EP1624105A1 - Alkanol-ammonia containing triazinylflavonat brightener - Google Patents

Abstract

Method for whitening paper in the size press comprises a size press fleet containing an alkanolammonium containing triazinyl flavone compound (I) as the optical whitener. Method for whitening paper in the size press comprises a size press fleet containing an alkanolammonium containing triazinyl flavone compound of formula (I) as the optical whitener. X : alkyl compounds of formula (a) or (b); either R 1>, R-1a : 1-6C alkyl; and R 2>, R-2a : H; or R 3>, R-3a : H, CH 3, CH 2CH 3, CH 2CH 2OH or CH 2CH 2OCH 3; R 4>H or 1-4C alkyl; M : an equivalent inorganic cation (preferably Li, Na, K, Ca, Mg or ammonium) or a substituted ammonium of formula (II) (where at least 10 mol.% of all cation corresponds to formula (II)); R 5>-R 7>H, 1-4C alkyl or optionally substituted 2-4C hydroxyalkyl; and R 8>optionally further substituted 2-4C hydroxy alkyl. Independent claims are also included for: (1) an optical whitener preparation comprising more than 50 (preferably more than 95) wt.% of (I); and (2) a size press fleet comprising (I) or an optical whitener preparation and at least a surface sizing agent (preferably starch). [Image] [Image] [Image].

Description

The invention relates to a process for lightening paper in the size press, whitener preparations and size press liquors.

In the production of paper, a sizing step is usually carried out to achieve good writability and strength, which can be done on the one hand before sheet formation in the pulp (engine sizing), on the other hand after sheet formation in the size press. A combination of these two methods is possible. In one or both stages of manufacture of the paper, a brightening of the paper pulp or of the paper sheet is usually carried out by optical brighteners, wherein usually in the mass application, the sizing agent and the brightener of the pulp are fed separately, while incorporated in surface sizing the brightener in the size press liquor and applied together with this on the paper sheet.

The combination of surface sizing and whitening of papers is widely used in the paper making industry. Especially in the paper segment Printing & Writing (Copy, Inkjet, Offset, etc.) this method is widely used. In addition to the more efficient lightening, a faster correction (online measurement) of the whiteness levels to be achieved is also possible. Furthermore, with the surface application, the wet end of additional anionic freights (whiteners) spared.

In GB-A-896,533, triazinyl flavonate brighteners are already described as K or Na salts as optical brighteners in the size press process for lightening paper. However, these still have some application disadvantages, in particular in the whiteness.

There is a continuing trend for top-grade papers with high levels of whiteness and, therefore, the desire for most effective optical brighteners as size press liquor component, especially those brighteners that do not have the disadvantages of the prior art.

worin

X

unabhängig voneinander einen Rest der Formel

oder

bedeutet und

R¹

für C₁-C₆-Alkyl und

R²

für H, oder

R¹

für H und

R²

für C₁-C₆-Alkyl steht, und unabhängig davon

R³

für H, Methyl, Ethyl, CH₂CH₂OH oder CH₂CH₂OCH₃ steht,

R^1'

für C₁-C₆-Alkyl und

R^2'

für H, oder

R^1'

für H und

R^2'

für C₁-C₆-Alkyl steht, und unabhängig davon

R^3'

für H, Methyl, Ethyl, CH₂CH₂OH oder CH₂CH₂OCH₃ sowie

R⁴

für C₁-C₄-Alkyl steht und

M

H, ein Äquivalent eines anorganischen Kations, insbesondere Li, Na, K, Ca, Mg oder Ammonium, oder ein substituiertes Ammonium der Formel II

bedeutet, wobei

R⁵ bis R⁷

unabhängig voneinander Wasserstoff, einen C₁-C₄-Alkylrest oder einen ggf. weiter substituierten C₂-C₄-Hydroxyalkylrest bedeuten, und R⁸ einen ggf. weiter substituierten C₂-C₄-Hydroxyalkylrest bedeutet,

wobei wenigstens 10 mol-% aller Kationen M der Formel II entsprechen.The invention therefore relates to a method for lightening paper in the size press, characterized in that the size press liquor contains a brightener of the formula I,

wherein

X

independently of one another a radical of the formula

or

means and

R ¹

for C ₁ -C ₆ -alkyl and

R ²

for H, or

R ¹

for H and

R ²

is C ₁ -C ₆ -alkyl, and independently thereof

R ³

is H, methyl, ethyl, CH ₂ CH ₂ OH or CH ₂ CH ₂ OCH ₃ ,

R ^{1 '}

for C ₁ -C ₆ -alkyl and

R ^{2 '}

for H, or

R ^{1 '}

for H and

R ^{2 '}

is C ₁ -C ₆ -alkyl, and independently thereof

R ^{3 '}

for H, methyl, ethyl, CH ₂ CH ₂ OH or CH ₂ CH ₂ OCH ₃ as well

R ⁴

is C ₁ -C ₄ -alkyl and

M

H, one equivalent of an inorganic cation, in particular Li, Na, K, Ca, Mg or ammonium, or a substituted ammonium of the formula II

means, where

R ⁵ to R ⁷

independently of one another are hydrogen, a C ₁ -C ₄ -alkyl radical or an optionally further substituted C ₂ -C ₄ -hydroxyalkyl radical, and R ^{8 is} an optionally further substituted C ₂ -C ₄ -hydroxyalkyl radical,

wherein at least 10 mol% of all cations M correspond to the formula II.

Preferably, at least 20 mol%, in particular more than 50 mol%, very particularly preferably more than 80 mol% of all cations M have the meaning of the formula II.

It is very particularly preferred to use brighteners containing more than 50% by weight, preferably more than 60% by weight, preferably more than 75% by weight, in particular more than 95% by weight, of a brightener Formula I exist.

• R¹ = H,
• R² = lineares C₁-C₆-Alkyl sowie
• R³ = H;

weiterhin der Formel (I) mit

• R^1' = H,
• R^2' = lineares C₁-C₆-Alkyl sowie
• R^3' = H und R4 = H oder Methyl,

in denen M jeweils eine Mischung von Kationen enthaltend Alkanolammoniumionen der Formel II, wobei die Reste R⁵ für H; R⁶ für H oder C₂-C₄-Hydroxyalkyl und R⁷ und R⁸ für C₂-C_4-Hydroxyalkyl stehen und Na- oder K-Ionen bedeutet.Preferred optical brighteners correspond to the formula (I) with

• R ¹ = H,
• R ² = linear C ₁ -C ₆ -alkyl and
• R ³ = H;

furthermore of the formula (I)

• R ^{1 '} = H,
• R ^{2 '} = linear C ₁ -C ₆ -alkyl and
• R ^{3 '} = H and R 4 = H or methyl,

in which M is in each case a mixture of cations containing alkanolammonium ions of the formula II, where the radicals R ^{5 are} H; R ^{6 is} H or C ₂ -C ₄ hydroxyalkyl and R ⁷ and R ^{8 are} C ₂ -C ₄ hydroxyalkyl and denote Na or K ions.

worin

M

eine Mischung enthaltend das Kation der Formel II

und Na⁺ oder K⁺ bedeutet.The brightener of the formula (Ia) is particularly preferably

wherein

M

a mixture containing the cation of formula II

and Na ⁺ or K ⁺ means.

The particular suitability of the alkanolammonium brightener of formula I for the inventive use means that in the event that at least one of R ⁵ -R ^{7 is} hydrogen, the pH in the size press liquor is preferably adjusted so that one for the present Amount of Aufhelleranionen optimal minimum amount of protonated alkanolamine is available. This is generally the case in the range of pH <= 7.5; preferably adjusted in the application medium, a pH at which as far as possible all present alkanolamine is protonated, ie, a pH range of 4-7.

In the inventive use of the brightener of the formula (I) may additionally be present in excess alkanolamine or alkanolammonium in the form of the free bases or corresponding salts with other, inorganic or organic, anions in the size press liquor.

Under size press is understood in the context of this invention, a surface application unit preferably the paper machine in which the cellulose sheet formed with an aqueous liquor containing at least one surface sizing agent, in particular starch, for example, native, derivatized or degraded, preferably oxidatively degraded starch, the so-called size press liquor brought into contact is, and in which the proportion of the fleet, which is to be absorbed by the sheet (liquor pickup) can be preferably adjusted by the roll pressure.

Recent developments in the size press, namely the Speedsizer as well as the Symsizer are also understood by the term size press.

Thus, e.g. the brighteners are already prepared and / or formulated in the form of their alkanolammonium salts or mixed salts of their alkanolammonium salts with their salts of inorganic bases and are finally incorporated into size press liquors in such a form which are then applied in the described preferred pH range. The use can, however, e.g. also be effected by reacting with an inorganic counterion, e.g. Lithium, sodium, potassium, calcium, magnesium, or ammonium whitening agent is contacted with the salt of an inorganic or organic acid of an alkanolamine, e.g., an alkanolamine hydrochloride or alkanolamine sulfate, and then applied in a size press liquor of suitable pH, or e.g. in that this matching only happens in the size press fleet, or z. B. also in that the alkanolamine underlying the alkanolamine is introduced in free form at any time and at any point in the manufacturing or processing and neutralized in the course with a suitable inorganic or organic acid. This of course also applies to the opposite case, namely that first the inorganic or organic acid and only then the alkanolamine is introduced.

The use according to the invention is preferably carried out by introducing into the size press liquor an aqueous solution of the brightener of suitable pH, which may possibly contain additional substances, such as carrier substances, salts or setting agents.

Suitable carrier substances are, for example, hydrophilic polymers capable of forming hydrogen bonds. Preferred carrier substances are polyvinyl alcohols, carboxymethylcelluloses and polyethylene glycols having a number-average molecular weight of from 200 to 8000 g / mol, as well as any desired mixtures of these substances, these polymers optionally being able to be modified. Preferred polyvinyl alcohols are those with a degree of hydrolysis> 85%, preferred carboxymethylcelluloses are those with a degree of substitution DS of> 0.5. Particularly preferred are polyethylene glycols having a number average molecular weight Mn of 200 to 8000 g / mol.

With such formulations, generally more favorable whiteness build-up curves and higher greening limits can be realized than with carrier-free whitener preparations.

In addition, in the carrier-free or carrier-containing formulations in smaller amounts, usually in amounts below 5 wt .-%, other auxiliaries such. As dispersants, thickeners, antifreeze, preservatives, complexing agents, etc., or organic by-products from the brightener synthesis, which were not completely removed in the workup, may be included.

If one compares the extinction-like use of the brighteners shown in formula (I) in a size press application in the form of their salts, where M are only inorganic cations, with their alkanolammonium-containing salts, the brightener with only inorganic cations shows a saturation behavior with respect to the CIE from certain brightener addition amounts. Whiteness, ie larger amounts do not lead to whiteness build-up any more and can even have a negative effect on the whiteness. This saturation behavior occurs when using the alkanolammonium brightener only at much higher levels, compared to the salt with only inorganic cations, on. As a result, it is possible with the alkanolammonium-containing formulations to achieve surprisingly higher degrees of whiteness than with formulations which contain only inorganic cations. The effect of saturation is also called greening. The greening border, i. the point above which increasing brightener amounts cause virtually no increase in whiteness can e.g. are derived from the a * -b * diagram, where a * and b * are the color coordinates in the CIE-L * a * b * system.

Aqueous whitener preparations are usually characterized by the so-called E1 / 1 value. For this purpose, the extinction of a highly diluted solution of the preparation is determined by the usual and known to the expert methods of UV / Vis spectroscopy in a 1 cm cuvette at a specific wavelength. This wavelength corresponds to the long-wavelength absorption maximum of the respective brightener molecule. For flavonate brighteners it is about 350 nm. The E1 / 1 value then corresponds to the imaginary extinction value extrapolated to a 1% solution of the sample to be determined.

Since the greening of alkanolammoniumhaltigen types only occurs at relatively high levels, their use according to the invention is particularly suitable for the production of high white papers. The exact conditions of use in which the greening in the size press application depends on the composition of the respective size press liquor.

In EP-A-1355004 brighteners of the formula (I) are also described, but they are mentioned there only in connection with the use in coating compositions.

WO 0046336 describes mixtures of brighteners which contain, inter alia, up to 45 mol% of brightener of the formula (I) where R ¹ = R ³ = H; R ² = methyl; M = Na, Li, Ca, Mg, ammonium or ammonium which is mono-, di-, tri-, or tetra-substituted by C ₁ -C ₄ alkyl or C ₁ -C ₄ hydroxyalkyl, which may contain, inter alia to lighten of paper. Whether these mixtures are particularly well suited for use in the size press, however, is nowhere mentioned. In addition, it could be shown by comparative investigations that the brightener of the formula Ia (corresponding to 1b from WO 00/46336) described in the present invention, when prepared according to the method described in WO 0046336, Example 2 as a single compound, in the size press application shows a significantly better brightening effect than the mixture prepared in the same way according to WO 0046336, and that this effect can be further increased by neutralizing the present excess alkanolamine.

The invention therefore furthermore relates to a whitener preparation comprising brighteners which contain more than 50% by weight, preferably more than 60% by weight, preferably more than 75% by weight, in particular more than 95% by weight, of a brightener of the formula I exist. Preference is given to aqueous whitener preparations which may optionally contain additional substances, such as those already mentioned, for example, above.

The preparations according to the invention can preferably be used in the lightening process according to the invention.

Particular preference is given to aqueous whitener preparations comprising at least one brightener of the formula (I), in particular (Ia).

The inventive, preferably aqueous brightener preparation preferably contains at least 2.5% by weight of brightener, particularly preferably 5 to 40% by weight, in particular 10 to 30% by weight.

Furthermore, the brightener preparations according to the invention may contain inorganic or organic salts, in addition free alkanolamine, in addition alkanolamine salts, carriers and other substances.

• a) wenigstens einen Aufheller der Formel (I) insbesondere (Ia) oder eine erfindungsgemäße Aufhellerpräparation und
• b) wenigstens ein Oberflächenleimungsmittel, vorzugsweise Stärke.

Another object of the invention are size press liquors, containing

• a) at least one brightener of the formula (I) in particular (Ia) or a whitener preparation according to the invention and
• b) at least one surface sizing agent, preferably starch.

Furthermore, the size press liquor may contain inorganic or organic salts, in addition free alkanolamine, in addition alkanolamine salts, carriers and other substances.

Preferably, the size press liquor contains less than 2.5% by weight of brightener, in particular from 0.01 to 2.0% by weight. The total brightener preferably consists, as already described for the whitener preparation, of more than 50% by weight, preferably more than 60% by weight, preferably more than 75% by weight, in particular more than 95% by weight, of one Brightener of formula I.

The proportion of surface sizing agent, in particular starch, based on the size press liquor, is preferably from 2 to 25% by weight, in particular from 5 to 15% by weight.

The water content of the size press liquor is preferably at least 70% by weight.

Examples Comparative Example 1 (Brightener from GB 896533, Example 2, lines 118-122; corresponds to brightener of the formula I of the present application, wherein the two anilene-bonded sulfo groups are p-continuous, with R ¹ = R ³ = H, R ² = CH ₃ , M only Na:

229 g of a membrane-filtered aqueous concentrate having an E1 / 1 value of 148 and a pH of 8.5, which contains the brightener of formula I with R ¹ = R ³ = H, R ² = CH ₃ , M exclusively Na , wherein the two aniloxed sulfo groups are p-type, are added with stirring at room temperature with 71 g of demineralized water and adjusted to pH 9.0 with about 10% sodium hydroxide solution. This gives an aqueous brightener preparation with an E1 / 1 value of 113 in the form of a yellow-brownish homogeneous liquid. This corresponds to a brightener content of approx. 21%

Comparative Examples 2a, b (corresponds to Comparative Example 1 with the difference that in addition different amounts of free triethanolamine are present):

229 g of the membrane-filtered aqueous concentrate from Comparative Example 1 are mixed with stirring at room temperature with a) 15.0 b) 30.0 and a) 56 g b) 41 g demineralized water and then stirred for 10 min. Triethanolamine-containing brightener preparations having an E1 / 1 value of 113 in the form of yellow-brownish homogeneous liquids are obtained. This corresponds to a content of brightener of about 21% and a content of triethanolamine of a) 5% b) 10%.

Comparative Example 3 corresponds to Example 2 of WO 00 46336. Examples 1a, 1b:

1200 g of the membrane-filtered aqueous concentrate from Comparative Example 1 are evaporated in vacuo. The crystallizate obtained has an E1 / 1 value of 472 after homogenization.

In each case a mixture of a) 140 g demineralized water and 15 g of triethanolamine, b) 90 g of demineralized water and 30 g of triethanolamine is adjusted to pH 6 by addition of a) about 36 g b) about 73 g, 10% hydrochloric acid. Subsequently, 71.8 g of the above-described crystals are introduced at about 60 ° C. with stirring. The mixture is stirred until the crystals have dissolved, the respective E1 / 1 value is determined, and the mixture is then diluted at room temperature with demineralized water to the same calculated E1 / 1 value of 113.

In each case about 300 g of a brightener setting is obtained which contains the same number of moles of brightener as comparative examples 1 or 2a, 2b and a) about 5% by weight (corresponds to an M with about 50 mol%). Triethanolammonium residue Na ⁺ ) b) about 10 wt .-% (corresponding to a M with about 100 mol% triethanolammonium) triethanolammonium ions.

Example 2

The procedure is up to and including the introduction of the crystals as described for Example 1b. After dissolution of the crystals, 15 g of polyethylene glycol 1500 are added, the mixture is stirred until dissolved and determines the E1 / 1 value. The mixture is then diluted at room temperature with demineralized water to a calculated E1 / 1 value of 113.

This gives about 300 g of a brightener formulation which contains the same number of moles of brighteners and triethanolammonium ions as in Example 1b and also 5% polyethylene glycol 1500 as a carrier.

Example 3 corresponds to Example 2 of WO 0046336 with the difference that the preparation of stage 2 is not carried out with the mixture of diethanolamine and diisopropanolamine described therein, but with an equimolar amount of this mixture diisopropanolamine. (M = about 50 mol% triethanolammonium).

Example 4 (corresponds to Example 2 of WO 0046336, with the difference that the preparation of stage 2 is not carried out with the mixture of diethanolamine and diisopropanolamine described therein, but with a mixture equimolar amount of diisopropanolamine, and in addition excess triethanolamine by adjustment of pH 6 with Hydrochloric acid has been neutralized (M = about 100 mol% triethanolammonium)

Application examples: General description of the brightener test / glue press application (applies to all application examples): 1. Equipment and aids

Starch solution 10%:

Perfectamyl A 4692 from Avebe (oxidatively degraded potato starch)

test paper:

Schleicher and Schuell MicroSience 3014, blanks 240X250 mm, Ref. No. 10344684

Laboratory size press, padder:

Fa. Mathis, type HF 52499, Zurich Oberhasli, Switzerland

2. Preparation of the starch solution

Approximately 120 g of Perfectamyl A 4692 are slurried with approx. 200 ml of cold water without lumps. Conn. About 700 ml of hot water are added with stirring to the initial charge and stirring is continued until a clear starch solution is formed. After cooling to room temperature, a concentration control by hand refractometer. Possibly. set by adding additional water to 10%.

3. Equipment of the papers

First, the liquor pick-up ratio of the test paper is determined in a separate determination.

For this purpose, 50.0 g of the 10% strength starch solution are diluted to 100.0 g with water, mixed thoroughly, the solution is transferred to the laboratory size press and a weighed sheet (weight 1 = m ₁ g) of the test paper is passed through the size press. The glue press speed should be around 4m / min and the roller contact pressure should be around 3 bar. Immediately after passing through the size press, the now moist sheet is weighed again (weight 2 = m ₂ g). The difference m ₂ -m ₁ gives the amount of liquor absorbed; Based on the weight of the sheet used, the liquor pickup ratio = (m ₂ -m ₁ ) / m _{1 is obtained} .

The test of the individual brightener preparations is then carried out by diluting the respective preparation as a concentration series to a further 50.0 g of the same starch solution, diluted to 100.0 g with water, thoroughly mixed, and the resulting brightener-containing size press liquors as described above Help the Apply the laboratory size press to further test paper sheets. Finally, the papers so finished in the drying cylinder at about 100 ° C dried.

The brightener preparations to be compared are each used in a concentration range of 0.5% by weight / 1.0% by weight / 1.5% by weight / 2.0% by weight, based on the weight of the test paper used. The relationship of the concentrations of brightener preparations in relation to the weight of the test paper to the corresponding concentrations in relation to the size of liquor press liquor is established using the previously separately determined liquor pick-up ratio. For example, at a liquor pick-up ratio of 0.9 in the experiment without brightener described above, the values of the above concentration series must still be divided by the divisor 0.9 to obtain their values in terms of size press liquor quantity.

Thus, for example, when using 0.5% by weight of whitener preparation based on test paper, at a liquor pick-up ratio of 0.9, an amount of 0.55% by weight of whitener preparation, based on the amount of size press liquor, results.

Furthermore, the above concentration series refers to preparations with an E1 / 1 value of 113. If preparations with a deviating E1 / 1 value are to be tested, their E1 / 1 value deviation from the guide value 113 must additionally be compensated for by: changing the concentration series in inverse proportion (for example, at an E1 / 1 value of 105, 0.538 wt% preparation is equivalent to 0.5% preparation of E1 / 1 value 113, etc.).

Application Example 1

Table 1: Brightener preparation from Comparative Example 1 Amount (%) CIE whiteness L * a * b * 0.50 138.08 95.95 2.96 -10.83 1.00 144.11 96.12 3.04 -12.13 1.50 145.80 96.28 2.87 -12.44 2.00 146.46 96.32 2.69 -12.57 Table 2: Brightener preparation from Comparative Example 2a Amount (%) CIE whiteness L * a * b * 0.50 135.50 95.92 2.83 -10.26 1.00 142.76 96.12 2.98 -11.82 1.50 144.48 96.28 2.83 -12.14 2.00 145.87 96.33 2.69 -12.43 Table 3: Brightener preparation from Comparative Example 2b Amount (%) CIE whiteness L * a * b * 0.50 135.40 95.82 2.84 -10.28 1.00 142.37 96.11 2.97 -11.73 1.50 144.24 96.22 2.87 -12.11 2.00 145.10 96.31 2.69 -12.26

It can be seen that the presence of triethanolamine in the form of the free base does not improve the lightening.

Application Example 2:

Table 1: Brightener preparation from Comparative Example 1 Amount (%) CIE whiteness L * a * b * 0.50 138.08 95.95 2.96 -10.83 1.00 144.11 96.12 3.04 -12.13 1.50 145.80 96.28 2.87 -12.44 2.00 146.46 96.32 2.69 -12.57 Table 4: Brightener preparation from Example 1a Amount (%) CIE whiteness L * a * b * 0.50 138.12 96.05 2.95 -10.80 1.00 145.36 96.31 3.09 -12.33 1.50 146.98 96.34 2.96 -12.68 2.00 148.48 96.57 2.79 -12.92 Table 5: Brightener preparation from Example 1b Amount (%) CIE whiteness L * a * b * 0.50 138.33 95.96 2.98 -10.88 1.00 145.58 96.26 3.12 -12.40 1.50 147.59 96.25 3.03 -12.86 2.00 148.26 96.46 2.80 -12.92

It can be seen that the presence of triethanolammonium causes a significant improvement in lightening.

Application Example 3

Table 5: Brightener preparation from Example 1b Amount (%) CIE whiteness L * a * b * 0.50 138.33 95.96 2.98 -10.88 1.00 145.58 96.26 3.12 -12.40 1.50 147.59 96.25 3.03 -12.86 2.00 148.26 96.46 2.80 -12.92 Table 6: Brightener preparation from Example 2 Amount (%) CIE whiteness L * a * b * 0.50 138.69 95.96 3.02 -10.97 1.00 145.83 96.23 3.16 -12.47 1.50 148.12 96.41 3.08 -12.92 2.00 148.74 96,39 2.86 -13.06

It can be seen that the lightening effect improved by triethanolammonium can be further increased by adding polyglycol.

Application Example 4: (all amounts used are based on an E _1/1 value of 113)

Table 7: Brightener preparation from Comparative Example 3 Amount (%) CIE whiteness L * a * b * 0.50 137.64 95.95 2.89 -10.73 1.00 144.62 96.29 2.95 -12.16 1.50 146.04 96.37 2.78 -12.45 2.00 147.17 96.5 2.56 -12.65 Table 8: Brightener preparation from Example 3 Amount (%) CIE whiteness L * a * b * 0.50 137.8 95.93 2.94 -10.78 1.00 145.6, 96.21 3.11 -12.43 1.50 147.6 96.32 2.96 -12.82 2.00 148.9 96.43 2.79 -13.08 Table 9: Brightener preparation from Example 4 Amount (%) CIE whiteness L * a * b * 0.50 138.9 95.94 2.99 -11.02 1.00 146.3 96.29 3.11 -12.55 1.50 148.4 96,39 2.97 -12.98 2.00 149.6 96.53 2.80 -13.19

It can be seen, on the one hand, that in the same extinction use, a brightener preparation containing the brightener of the formula Ia (with diisopropanolamine residues on the triazine rings prepared analogously to Example 2 of WO 0046336) has a better brightening effect than the brightener preparation of Example 2 of WO 0046336, which contains a brightener mixture which additionally contains a brightener substituted with diethanolamine radicals on the triazine rings and a brightener unsymmetrically substituted with diisopropanolamine radicals and diethanolamine radicals on the triazine rings, and on the other hand that the brightening effect can be additionally increased if the free triethanolamine which is used in the procedure of Example 2 of WO 0046336 prepared whitener preparation containing the brightener of formula Ia, is neutralized by the addition of acid.

Claims (6)

A process for lightening paper in the size press, characterized in that the size press liquor contains a brightener of the formula I,

wherein X is independently a radical of the formula

or

means and R ^{1 is} C ₁ -C ₆ -alkyl and R ² for H, or R ¹ for H and R ^{2 is} C ₁ -C ₆ alkyl, and independently thereof R ^{3 is} H, methyl, ethyl, CH ₂ CH ₂ OH or CH ₂ CH ₂ OCH ₃ , R ^{1 '} for C ₁ -C ₆ alkyl and R ^{2 '} for H, or R ^{1 '} for H and R ^{2 'is} C ₁ -C ₆ alkyl, and independently thereof R ^{3 '} for H, methyl, ethyl, CH ₂ CH ₂ OH or CH ₂ CH ₂ OCH ₃ and R ^{4 is} C ₁ -C ₄ alkyl and MH, one equivalent of an inorganic cation, in particular Li, Na, K, Ca, Mg or ammonium, or a substituted ammonium of the formula II

means, where R ⁵ to R ⁷ independently of one another are hydrogen, a C ₁ -C ₄ -alkyl radical or an optionally further substituted C ₂ -C ₄ -hydroxyalkyl radical, and R ^{8 is} an optionally further substituted C ₂ -C ₄ -hydroxyalkyl radical,
wherein at least 10 mol% of all cations M correspond to the formula II. Process according to Claim 1, characterized in that the size press liquor contains brighteners which contain more than 50% by weight, preferably more than 60% by weight, preferably more than 75% by weight, in particular more than 95% by weight. consist of a brightener of formula I. Method according to at least one of claims 1 or 2, characterized in that R ¹ = H, R ² = linear C ₁ -C ₆ -alkyl and R ³ = H;
furthermore of the formula (I) R ¹ = H, R ^{2 '} = linear C ₁ -C ₆ -alkyl and R ^{3 '} = H and R 4 = H or methyl,
in which M is in each case a mixture of cations containing alkanolammonium ions of the formula II, where the radicals R ^{5 are} H; R ^{6 is} H or C ₂ -C ₄ -hydroxyalkyl and R ⁷ and R ^{8 are} C ₂ -C ₄ -hydroxyalkyl and denote Na or K ions. Method according to at least one of claims 1 to 4, characterized in that a brightener of formula Ia is used

wherein M is a mixture containing the cation of formula II

and Na ⁺ or K ⁺ means. Brightener preparation containing brighteners consisting of more than 50 wt .-%, preferably more than 60 wt .-%, preferably more than 75 wt .-%, in particular more than 95 wt .-% of a brightener of the formula I.

wherein X is independently a radical of the formula

or

means and R ^{1 is} C ₁ -C ₆ -alkyl and R ² for H, or R ¹ for H and R ^{2 is} C ₁ -C ₆ alkyl, and independently thereof R ^{3 is} H, methyl, ethyl, CH ₂ CH ₂ OH or CH ₂ CH ₂ OCH ₃ , R ^{1 '} for C ₁ -C ₆ alkyl and R ^{2 '} for H, or R ^{1 '} for H and R ^{2 'is} C ₁ -C ₆ alkyl, and independently thereof R ^{3 '} for H, methyl, ethyl, CH ₂ CH ₂ OH or CH ₂ CH ₂ OCH ₃ and R ^{4 is} C ₁ -C ₄ alkyl and MH, one equivalent of an inorganic cation, in particular Li, Na, K, Ca, Mg or ammonium, or a substituted ammonium of the formula II

means, where R ⁵ to R ⁷ independently of one another are hydrogen, a C ₁ -C ₄ -alkyl radical or an optionally further substituted C ₂ -C ₄ -hydroxyalkyl radical, and R ^{8 is} an optionally further substituted C ₂ -C ₄ -hydroxyalkyl radical,
wherein at least 10 mol% of all cations M correspond to the formula II. Containing size press fleet a) at least one brightener of the formula (1) in particular (Ia) or a brightener preparation according to claim 5 and b) at least one surface sizing agent, in particular starch.