阅读说明：本技术 用于增白纸的光学增亮剂 (Optical brightening agent for whitening paper ) 是由 克里斯蒂娜·多明格斯 安德鲁·杰克逊 戴维·阿特金森 梅拉尔·伊兰 马克·布可夫斯基 于 2018-12-14 设计创作，主要内容包括：本发明涉及一种用于增白和增亮纸、纸板、纺织品和非织造物的光学增亮剂,一种制备所述光学增亮剂的方法,所述增亮剂在造纸工艺中的用途和增白纸的方法。(The present invention relates to an optical brightener for whitening and brightening paper, paperboard, textiles and nonwovens, a process for preparing the optical brightener, the use of the brightener in a papermaking process and a process for whitening paper.)

1. A compound of formula (2)

Wherein

Z¹And Z²Each independently represents OR⁹OR OR¹⁰Wherein

R⁹And R¹⁰Each independently represents a linear C₁To C₃Alkyl or branched C₃An alkyl group; or

Z¹And Z²Each independently represents NR²R³Or NR⁴R⁵Wherein

R²And R⁴Each independently represents hydrogen, linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, linear C₂、C₃Hydroxyalkyl or branched C₃Hydroxyalkyl, CH₂CO₂M、CH₂CH₂CONH₂Or CH₂CH₂CN，

R³And R⁵Each independently represents a linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, linear C₂、C₃Hydroxyalkyl or branched C₃Hydroxyalkyl, CH₂CH₂SO₃M CH₂CO₂M、CH(CO₂M)CH₂CO₂M or CH (CO)₂M)CH₂CH₂CO₂M, benzyl, or

R²And R³

And/or

R⁴And R⁵Together with their adjacent nitrogen atom represent a morpholine ring, an

R¹And R⁶Each independently represents hydrogen, other linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, linear C₂To C₃Hydroxyalkyl or branched C₃Hydroxyalkyl, CH₂CH₂CONH₂Or CH₂CH₂CN，

R⁷And R⁸Each independently represents hydrogen, linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, provided that R is⁷Or R⁸Is linear C₁To C₄Alkyl or branched C₃、C₄An alkyl group;

x and Y each independently represent CO₂M or SO₃M，

m and n are 0, 1 or 2, with the proviso that at least one of m or n is at least 1, and

m represents a cation for balancing anionic charge selected from the group comprising or consisting essentially of: hydrogen, alkali metal cation, alkaline earth metal cation, ammonium, linear C₁To C₄Alkyl or branched C₃、C₄Ammonium mono-, di-, tri-or tetrasubstituted with alkyl, by linear C₁To C₄Hydroxyalkyl or branched C₃、C₄Ammonium mono-, di-, tri-or tetrasubstituted with hydroxyalkyl radicals, by linear C₁To C₄Alkyl or branched C₃、C₄Alkyl or linear C₁To C₄Hydroxyalkyl or branched C₃、C₄Mixtures of hydroxyalkyl di-, tri-or tetra-substituted ammonium or saidA mixture of the cations of the organic acid,

wherein if R is⁷Is linear C₁To C₄Alkyl or branched C₃、C₄N is at least 1, and/or if R is alkyl⁸Is linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, then m is at least 1.

2. The compound of claim 1, wherein R⁹And R¹⁰Each independently represents a methyl group, an ethyl group, a propyl group or an isopropyl group, preferably a methyl group.

3. The compound of claim 1, wherein R⁷And/or R⁸Represents hydrogen, methyl or ethyl, preferably R⁷And R⁸One or two of which are each at R bearing a nitrogen atom¹Or R⁶Para with the proviso that R is⁷Or R⁸At least one of which is methyl or ethyl.

4. A compound according to claim 1 or 3, wherein R⁷And/or R⁸Represents methyl, preferably R⁷And R⁸One or two of which are each at R bearing a nitrogen atom¹Or R⁶And (4) contraposition.

5. The compound according to at least one of claims 1 to 3, wherein

X and Y represent SO₃M, and

m represents a cation for balancing the anionic charge selected from the group consisting of L i⁺、Na⁺、K⁺、¹/₂Ca²⁺、¹/₂Mg²⁺Is linear C₁To C₄Alkyl or branched C₃、C₄Ammonium mono-, di-, tri-or tetrasubstituted with alkyl, by linear C₁To C₄Hydroxyalkyl or branched C₃、C₄Ammonium mono-, di-, tri-or tetrasubstituted with hydroxyalkyl radicals, by linear C₁To C₄Alkyl or branchedModified C₃、C₄Alkyl or linear C₁To C₄Hydroxyalkyl or branched C₃、C₄A mixture of hydroxyalkyl di-, tri-or tetra-substituted ammonium, and

m and n are each a number 1,

or therein

X and Y represent SO₃M, and

m represents Na⁺And is and

m and n are 1.

6. A compound according to claim 5, wherein X is at R carrying a nitrogen atom¹And Y is in the meta position of (A) and R carrying a nitrogen atom⁶Meta position of (b).

7. The compound according to at least one of claims 1 and 3 to 6, wherein R¹And/or R⁶Represents hydrogen.

8. The compound according to at least one of claims 1 and 3 to 7, wherein

R²And R⁴

And/or

R³And R⁵Each independently represents hydroxyethyl and/or hydroxyisopropyl, preferably hydroxyethyl.

9. A concentrated aqueous composition comprising from 5 to 60% by weight of at least one compound of formula (2) according to at least one of claims 1 to 8.

10. A concentrated aqueous composition according to claim 9 comprising one or more additives of: biocides, thickeners, shading colorants, solubilizers, polymers such as poly (vinyl alcohol) and polyethylene glycol, or inorganic salts such as sodium chloride.

11. The aqueous composition of claim 9 or 10, wherein the aqueous composition is a slurry.

12. A process for the preparation of compounds of the formula (2) according to at least one of claims 1 to 8, wherein in a first step cyanuric halide is reacted with

A compound of formula (4) and/or a compound of formula (5)

Wherein

R⁷、R⁸X, Y, m and n have the meanings defined in at least one of claims 1 to 6, and wherein in the second step the reaction product of the first step is reacted with

A compound of formula (6)

Wherein M has the meaning defined in at least one of claims 1 to 5,

or wherein a cyanuric halide is reacted in a first step with a compound of formula (6) and the reaction product of the first step is reacted in a second step with a compound of formula (4) and/or formula (5),

and wherein the reaction product of the second step is reacted in a third step with a compound of formula (7) and/or a compound of formula (8)

Wherein R is²、R³、R⁴、R⁵Has the meaning as defined in claim 1 or 8, or

Wherein the reaction product of the second step is reacted in a third step with a compound of formula (9) and/or a compound of formula (10)

H-OR⁹(9)

H-OR¹⁰(10)

Wherein R is⁹And R¹⁰Have the meaning defined in claim 1 or 2.

13. The process according to claim 12, wherein the reaction is carried out in an aqueous medium and the first step is carried out at a temperature in the range of 0 ℃ to 20 ℃ and at a pH in the range of 4 to 6, the second step is carried out at a temperature in the range of 20 to 80 ℃ and at a pH in the range of 6 to 7.5, and the third step is carried out at a temperature in the range of 60 ℃ to 102 ℃ and at a pH in the range of 7.5 to 9.

14. A method of whitening paper comprising the steps of:

providing a suspension of a pulp slurry, and,

adding from 0.01 to 5% by weight, based on dry fibers of the pulp, of an aqueous composition according to at least one of claims 9 to 11 to obtain a brightened pulp,

the moisture of the blend was drained off,

the blend was pressed and dried to form paper.

15. Use of a compound of formula (2) according to at least one of claims 1 to 8 or a concentrated aqueous composition according to at least one of claims 9 to 11 for optical brightening of textiles, paper, cardboard and nonwovens.

16. Use according to claim 15, wherein the compound of formula (2) is added to pulp.

Background

The present invention relates to an optical brightener for whitening and brightening paper, paperboard, textiles and nonwovens, a process for preparing the optical brightener, the use of the brightener in a papermaking process and a process for whitening paper.

High levels of whiteness (commonly referred to as CIE whiteness) and brightness (e.g., ISO brightness) are important parameters for evaluating the quality of cellulosic substrates, particularly paper products for end users. The most important raw materials for these products are cellulose, pulp and lignin. However, these materials naturally absorb blue light, so the color is yellowish and gives the product a dull appearance.

To compensate for the natural absorption of blue light by the raw materials, optical brighteners (also known as optical brightening agents or OBAs, or fluorescent whitening agents or FWAs) are used. OBAs typically absorb UV light with a maximum wavelength of 350nm to 360nm and convert this absorbed light into visible blue light with a maximum wavelength of 440 nm.

The optical properties of products formed from cellulosic substrates were evaluated according to known standard procedures for CIE whiteness and ISO brightness measurements. The CIE whiteness values are derived from measurements of light reflected by the paper over the entire visible spectrum. Brightness is a measure of the amount of blue light reflected.

It is known in the art to apply Optical Brighteners (OBAs) to paper, paperboard, textiles and nonwovens by different methods to improve the whiteness, brightness and appeal of these products. The most widely used optical brighteners in these industries are anilino-substituted bistriazinyl derivatives of 4, 4 '-diaminostilbene-2, 2' -disulphonic acid.

In the paper industry, the most widely used OBA is of formula (1). The OBA of formula (1) provides flexibility of application at the wet end (application to the stock) or application to the paper surface using sizing or coating techniques at any point in the paper machine. Other OBAs in which the anilino substituent contains two sulfonic acid groups provide particularly high whiteness when applied to the paper surface.

EP 0884312a1 discloses a formulation comprising an optical brightener in an active substance concentration of more than 30% by weight. The active substance is a hydrate of 4, 4 '-bistriazinylamino-2, 2' -disulfostilbene which carries no substituents on the terminal anilino substituents.

WO 2010/060570a1 discloses optical brightening compositions comprising bis (triazinylamino) stilbene type OBAs containing two sulpho groups on the terminal anilino substituent. The whitening agent is well compatible with sizing compositions containing divalent metal salts.

There is a continuing need in the paper industry to provide improved OBAs and OBA compositions. It is therefore an object of the present invention to provide OBAs capable of delivering whiteness and brightness with higher efficiency with the attendant benefits of improved sustainability and reduced cost while maintaining good affinity to cellulosic substrates such as paper and paperboard.

Disclosure of Invention

In a first aspect of the invention, the object is solved by compounds of the formula (2)

Wherein

Z¹And Z²Each independently represents OR⁹OR OR¹⁰Wherein

R⁹And R¹⁰Each independently represents a linear C₁To C₃Alkyl or branched C₃Alkyl, or

Z¹And Z²Each independently represents NR²R³Or NR⁴R⁵Wherein

R²And R⁴Each independently represents hydrogen, linear C₁To C₄Alkyl or branchedC of (A)₃、C₄Alkyl, linear C₂To C₃Hydroxyalkyl or branched C₃Hydroxyalkyl, CH₂CO₂M、CH₂CH₂CONH₂Or CH₂CH₂CN，R³And R⁵Independently of one another, linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, linear C₂To C₃Hydroxyalkyl or branched C₃Hydroxyalkyl, CH₂CH₂SO₃M CH₂CO₂M、CH(CO₂M)CH₂CO₂M or CH (CO)₂M)CH₂CH₂CO₂M, benzyl, or

R²And R³

And/or

R⁴And R⁵Together with their adjacent nitrogen atom represent a morpholine ring, an

R¹And R⁶Each independently represents hydrogen, linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, linear C₂To C₃Hydroxyalkyl or branched C₃Hydroxyalkyl, CH₂CH₂CONH₂Or CH₂CH₂CN，

R⁷And R⁸Each independently represents hydrogen, linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, provided that R is⁷Or R⁸Is linear C₁To C₄Alkyl or branched C₃、C₄An alkyl group, a carboxyl group,

x and Y each independently represent CO₂M or SO₃M，

m and n are 0, 1 or 2, with the proviso that at least one of m or n is at least 1, and

m represents a cation for balancing anionic charge selected from the group comprising or consisting essentially of: hydrogen, alkali metal cation, alkaline earth metal cation, ammonium, linear C₁To C₄Alkyl or branched C₃、C₄Ammonium mono-, di-, tri-or tetrasubstituted with alkyl, by linear C₁To C₄Ammonium mono-, di-, tri-or tetrasubstituted with hydroxyalkyl or branched hydroxyalkyl groups, by linear C₁To C₄Alkyl or branched C₃、C₄Alkyl or linear C₁To C₄Hydroxyalkyl or branched C₃、C₄Mixtures of hydroxyalkyl groups or mixtures of said cations,

wherein if R is⁷Is linear C₁To C₄Alkyl or branched C₃、C₄N is at least 1, and/or if R is alkyl₈Is linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, then m is at least 1.

Preferably, according to the first aspect of the invention, R⁷And/or R⁸Represents hydrogen, methyl or ethyl, preferably R⁷And R⁸One or two of which are each at R bearing a nitrogen atom¹Or R⁶Para with the proviso that R is⁷Or R⁸At least one of which is methyl or ethyl.

Preferably, according to the first aspect of the invention, R⁷And/or R⁸Represents methyl, preferably R⁷And R⁸One or two of which are each at R bearing a nitrogen atom¹Or R⁶And (4) contraposition.

Preferably, according to the first aspect of the invention,

x and Y represent SO₃M, and

m represents a cation for balancing the anionic charge selected from the group consisting of L i⁺、Na⁺、K⁺、1/2Ca²⁺、1/2Mg²⁺Is linear C₁To C₄Hydroxyalkyl or branched C₃、C₄Ammonium mono-, di-, tri-or tetrasubstituted with hydroxyalkyl radicals, by linear C₁To C₄Alkyl or branched C₃、C₄Alkyl and linear C₁To C₄Hydroxyalkyl or branched C₃、C₄Ammonium di-, tri-or tetrasubstituted with mixtures of hydroxyalkyl radicals, or the cationsA mixture of seeds, and

m and n are each a number 1,

or therein

X and Y represent SO₃M, and

m represents Na⁺And is and

m and n are 1.

Preferably, according to the first aspect of the invention, X is at R carrying a nitrogen atom¹And Y is in the meta position of (A) and R carrying a nitrogen atom⁶Meta position of (b).

Preferably, according to the first aspect of the invention, R⁹And R¹⁰Each independently represents a methyl group, an ethyl group, a propyl group or an isopropyl group, preferably a methyl group.

Preferably, according to the first aspect of the invention, R¹And/or R⁶Represents hydrogen.

Preferably, according to the first aspect of the invention,

R²and R⁴

And/or

R³And R⁵Each independently represents a hydroxymethyl group and/or a hydroxyisopropyl group, preferably a hydroxyethyl group.

In a second aspect, the present invention relates to a concentrated aqueous composition comprising 5 to 60% by weight of at least one compound of formula (2) according to at least one embodiment of the first aspect of the present invention.

Preferably, according to the second aspect of the invention, the concentrated aqueous composition comprises one or more additives of: biocides, thickeners, shading colorants, solubilizers, polymers such as poly (vinyl alcohol) and polyethylene glycol, or inorganic salts such as sodium chloride.

Preferably, according to the second aspect of the invention, the concentrated aqueous composition is in the form of a slurry.

In a third aspect, the present invention relates to a process for the preparation of a compound of formula (2) according to at least one embodiment of the first aspect of the present invention, wherein in a first step a cyanuric halide is reacted with a compound of formula (4) and/or a compound of formula (5) below

Wherein

R⁷、R⁸X, Y, m and n have the meanings defined in at least one embodiment according to the first aspect of the invention, and wherein in the second step the reaction product of the first step is reacted with

A compound of formula (6)

Wherein M has the meaning defined in at least one of the above embodiments,

or wherein the cyanuric halide is reacted in a first step with a compound of formula (6) and the product of the first step is reacted in a second step with a compound of formula (4) and/or formula (5),

and wherein the reaction product of the second step is reacted in a third step with

A compound of formula (7) and/or a compound of formula (8)

Wherein R is²、R³、R⁴、R⁵Has the meaning as defined above, or

Wherein the reaction product of the second step is reacted in a third step with a compound of formula (9) and/or a compound of formula (10)

H-OR⁹(9)

H-OR¹⁰(10)

Wherein R is⁹And R¹⁰Have the meaning defined above.

Preferably, according to the third aspect of the invention, the reaction is carried out in an aqueous medium and the first step is carried out at a temperature in the range of 0 ℃ to 20 ℃ and a pH in the range of pH 4 to 6, the second step is carried out at a temperature in the range of 20 ℃ to 80 ℃ and a pH in the range of pH 6 to 7.5, and the third step is carried out at a temperature in the range of 60 ℃ to 102 ℃ and a pH in the range of pH 7.5 to 9.

In a fourth aspect, the present invention relates to a method of whitening paper comprising the steps of:

providing a suspension of a pulp slurry, and,

adding from 0.01 to 5% by weight, based on dry fibres of the pulp, of an aqueous composition according to at least one embodiment of the second aspect of the invention to obtain a brightened pulp,

the moisture of the blend was drained off,

the blend was pressed and dried to form paper.

In a fifth aspect, the present invention relates to a composition for surface brightening of paper comprising at least one surface sizing agent and at least one compound of formula (2) according to at least one embodiment of the first aspect of the invention and water.

Preferably, according to the fifth aspect of the present invention, the surface sizing agent comprises one or more starch materials.

Preferably, according to the fifth aspect of the invention, the one or more starch materials are selected from the group consisting of: enzymatically, chemically or thermally modified starch, oxidized starch, hydroxyethylated starch, acetylated starch, native starch, anionic starch, cationic starch or amphiphilic starch.

Preferably, according to the fifth aspect of the present invention, the amount of surface sizing agent in the surface brightening composition is from 1 wt% to 30 wt%, preferably from 2 wt% to 20 wt%, more preferably from 5 wt% to 15 wt%, said wt% being based on the total weight of the surface brightening composition.

Preferably, according to the fifth aspect of the present invention, the surface brightening composition has a pH in the range of 4 to 13, preferably 6 to 11.

In a sixth aspect, the present invention relates to the preparation of a surface brightening composition by adding a compound of formula (2) according to at least one embodiment of the first aspect of the present invention as optical brightener to a pre-made aqueous solution of a surface sizing agent at a temperature of 20 ℃ to 90 ℃.

In a seventh aspect, the present invention relates to a pigmented coating composition comprising at least one pigment, at least one binder, at least one compound of formula (2) according to at least one embodiment of the first aspect of the invention and water.

Preferably, according to a seventh aspect of the present invention, the pigmented coating composition comprises 10 to 70 wt. -%, preferably 40 to 60 wt. -% of at least one white pigment, wherein wt. -% is based on the total weight of the pigmented coating composition.

Preferably, according to a seventh aspect of the present invention, the pigmented coating composition comprises 0.01 to 1 wt. -%, preferably 0.05 to 0.5 wt. -% of a compound of formula (2) according to at least one embodiment of the first aspect of the present invention, said wt. -% being based on the total weight of the dry weight of white pigments in the pigmented coating composition.

Preferably, according to a seventh aspect of the invention, the white pigment is selected from the group consisting of: aluminum silicate, calcium carbonate, titanium dioxide, aluminum hydroxide, barium carbonate, barium sulfate, and calcium sulfate, or mixtures thereof.

Preferably, according to a seventh aspect of the invention, the binder is selected from a first binder comprising one or more of a synthetic latex, styrene-butadiene, vinyl acetate, styrene acrylic, vinyl acrylic or ethylene vinyl acetate polymer, and optionally a second binder comprising one or more of starch, carboxymethyl cellulose, casein, soy polymer, polyvinyl alcohol.

In an eighth aspect, the present invention relates to a detergent composition comprising one or more surfactants and at least one compound of formula (2) according to at least one embodiment of the first aspect of the present invention.

Preferably, according to an eighth aspect of the invention, the detergent composition is in liquid form and the amount of the compound of formula (2) is from 0.005 wt% to 1 wt%, preferably from 0.01 wt% to 0.5 wt%, most preferably from 0.02 wt% to 0.25 wt%. The wt% is based on the total weight of the detergent composition.

Preferably, according to an eighth aspect of the present invention, the detergent composition further comprises a builder (builder) selected from alkali metal polyphosphates, sodium carbonate and zeolites, an anti-redeposition agent selected from carboxymethylcellulose and poly (vinylpyrrolidone), and an enzyme selected from proteases, amylases and lipases.

In a ninth aspect, the present invention relates to the use of a compound of formula (2) according to at least one embodiment of the first aspect of the present invention, or the use of an aqueous composition according to at least one embodiment of the second aspect of the present invention, for optical brightening of textiles, paper, cardboard and nonwovens.

Preferably, according to a ninth aspect, the present invention relates to the use of a compound of formula (2) according to at least one embodiment of the first aspect of the present invention in a papermaking process, wherein the compound of formula (2) is added to the pulp.

Preferably, according to a ninth aspect, the present invention relates to the use of a compound of formula (2) according to at least one embodiment of the first aspect of the present invention in a composition for brightening a paper surface according to at least one embodiment of the fifth aspect of the present invention, or in a colored coating composition according to at least one embodiment of the seventh aspect of the present invention, or in a detergent composition according to at least one embodiment of the eighth aspect of the present invention.

Detailed Description

In a first aspect, the present invention relates to a compound of formula (2)

Wherein

Z¹And Z²Each independently represents OR⁹OR OR¹⁰Wherein

R⁹And R¹⁰Each independently represents a linear C₁To C₃Alkyl or branched C₃Alkyl, or

Z¹And Z²Each independently represents NR²R³Or NR⁴R⁵Wherein

R²And R⁴Each independently represents hydrogen, linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, linear C₂、C₃Hydroxyalkyl or branched C₃Hydroxyalkyl, CH₂CO₂M、CH₂CH₂CONH₂Or CH₂CH₂CN，

R³And R⁵Each independently represents a linear or branched C₁To C₄Alkyl, linear C₂To C₃Hydroxyalkyl or branched C₃Hydroxyalkyl, CH₂CH₂SO₃M CH₂CO₂M、CH(CO₂M)CH₂CO₂M or CH (CO)₂M)CH₂CH₂CO₂M, benzyl, or

R²And R³

And/or

R⁴And R⁵Together with their adjacent nitrogen atom represent a morpholine ring, an

R¹And R⁶Each independently represents hydrogen, linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, linear C₂To C₃Hydroxyalkyl or branched C₃Hydroxyalkyl, CH₂CH₂CONH₂Or CH₂CH₂CN，

R⁷And R⁸Each independently represents hydrogen, linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, provided that R is⁷Or R⁸Is linear C₁To C₄Alkyl or branched C₃、C₄An alkyl group, a carboxyl group,

x and Y each independently represent CO₂M or SO₃M，

m and n are 0, 1 or 2, with the proviso that at least one of m or n is at least 1, and

m represents a cation for balancing anionic charge selected from the group comprising or consisting essentially of: hydrogen, alkali metal cations, alkaline earth metal cationsSeed, ammonium, quilt linear C₁To C₄Alkyl or branched C₃、C₄Ammonium mono-, di-, tri-or tetrasubstituted with alkyl, by linear C₁To C₄Hydroxyalkyl or branched C₃、C₄Ammonium mono-, di-, tri-or tetrasubstituted with hydroxyalkyl radicals, by linear C₁To C₄Alkyl or branched C₃、C₄Alkyl or linear C₁To C₄Hydroxyalkyl or branched C₃、C₄Mixtures of hydroxyalkyl groups or mixtures of said cations,

wherein if R is⁷Is linear C₁To C₄Alkyl or branched C₃、C₄N is at least 1, and/or if R is alkyl⁸Is linear C₁To C₄Alkyl or branched C₃、C₄Alkyl, then m is at least 1.

The compounds of formula (2) have surprisingly good whitening and lightening effects while retaining good affinity to cellulose fibres. Thus, smaller amounts of the compound of formula (2) are needed to achieve the desired whitening effect on paper or paperboard, with the benefit of improved sustainability and reduced cost.

In the present application, the compound of formula (2) is referred to as Optical Brightener (OBA).

In this connection, the inventors have found that if at least one terminal anilino substituent in the compound of formula (2) simultaneously carries a linear or branched C₁To C₄Alkyl and at least one SO₃M or CO₂M groups, the quality of OBA in whitening and brightening properties is improved.

The compound of formula (2) may be applied to the cellulose fibres by addition to the stock or by treating the surface of the paper in a sizing or coating composition.

In certain embodiments, the compound of formula (2) is characterized by R⁹Or R¹⁰Independently of one another, methyl, ethyl, propyl, branched-chain propyl, butyl or branched butyl. In other embodiments, R⁹And R¹⁰Same, preferably R⁹And R¹⁰All represent methyl, i.e. Z¹And Z²Represents O-CH₃。

Preferably, the compound of formula (2) is characterized by R⁷And/or R⁸Is hydrogen, methyl or ethyl, preferably R⁷And R⁸One or two of which are each at R bearing a nitrogen atom¹Or R⁶Para with the proviso that R is⁷Or R⁸At least one of which is methyl or ethyl.

Preferably, the compound of formula (2) is characterized by R⁷And/or R⁸Represents methyl, preferably R⁷And R⁸One or two of which are each at R bearing a nitrogen atom¹Or R⁶And (4) contraposition. It has been surprisingly found that when R is⁷And R⁸In the case of methyl, affinity and affinity for cellulose fibers are improved.

According to one embodiment of the first aspect of the present invention, the sum of m and n is 2, 3 or 4. In one embodiment, m-n-2 is excluded. Preferably, m-n-1.

Preferably, the compounds of formula (2) are characterized in that

X and Y represent SO₃M, and

m represents a cation for balancing the anionic charge selected from the group consisting of L i⁺、Na⁺、K⁺、1/2Ca²⁺、1/2Mg²⁺Is linear C₁To C₄Alkyl or branched C₃、C₄Ammonium mono-, di-, tri-or tetrasubstituted with alkyl, by linear C₁To C₄Hydroxyalkyl or branched C₃、C₄Ammonium mono-, di-, tri-or tetrasubstituted with hydroxyalkyl radicals, by linear C₁To C₄Alkyl or branched C₃、C₄Alkyl or linear C₁To C₄Hydroxyalkyl or branched C₃、C₄A mixture of hydroxyalkyl di-, tri-or tetra-substituted ammonium, and

m and n are each a number 1,

or therein

X and Y represent SO₃M, and

m represents Na⁺、K⁺、Li⁺Trimethyl ammonium and dimethylethanolammonium, and

m and n are 1.

In the present application, the term "1/2 Ca²⁺"and" 1/2Mg²⁺The "representational form symbol" is used to indicate the equilibrium stoichiometry of the cationic and anionic charges in the compound of formula (2). Effectively, one divalent calcium or magnesium cation compensates for two anionic charges originating from one or both compounds of formula (2).

Preferably, the compounds of formula (2) are characterized in that X is at R carrying a nitrogen atom¹And Y is in the meta position of (A) and R carrying a nitrogen atom⁶Meta position of (b).

Preferably, the compound of formula (2) is characterized by R¹And/or R⁶Represents hydrogen.

Preferably, the compound of formula (2) is characterized by R²And R⁴And/or R³And R⁵Independently of one another, hydroxyethyl and/or hydroxyisopropyl, preferably hydroxyethyl.

In a second aspect, the present invention relates to an aqueous composition comprising or consisting of 5 to 60% by weight, relative to the total weight of the aqueous composition, of at least one compound of formula (2).

Preferably, the amount of the compound of formula (2) in the aqueous composition is at least 7.5 wt.%, or at least 10 wt.%, or at least 12.5 wt.% or at least 15 wt.%, and at most 55 wt.%, or at most 50 wt.%, or at most 45 wt.%, or at most 40 wt.%, preferably from 7.5 to 55 wt.%, or from 10 to 50 wt.%, or from 12.5 to 45 wt.%, or from 15 to 40 wt.%, wherein the wt.% is based on the total weight of the aqueous composition.

The aqueous composition according to the invention may contain one or more additives selected from the group consisting of: biocides, thickeners, shading colorants, solubilizers, polymers such as poly (vinyl alcohol) and polyethylene glycol, or inorganic salts such as sodium chloride.

The term "aqueous composition" as used in the context of the present application refers to a water-based composition, i.e. the composition comprises water.

In a third aspect, the present invention relates to a process for the preparation of a compound of formula (2) according to any one of the embodiments of the first aspect of the present invention. Said method is characterized in that the cyanuric halide is reacted in a first step with a compound of formula (4) and/or a compound of formula (5)

Wherein

R⁷、R⁸X, Y, m and n have the meanings defined above, and wherein in a second step the reaction product of the first step is reacted with

Diamine compound of formula (6)

Wherein M has the meaning as defined above,

or wherein the cyanuric halide is reacted in a first step with a compound of formula (6) and the reaction product of the first step is reacted in a second step with a compound of formula (4) and/or a compound of formula (5)

And wherein the reaction product of the second step is reacted in a third step with

A compound of formula (7) and/or a compound of formula (8)

Wherein R is²、R³、R⁴、R⁵Has the meaning as defined above, or

Wherein the reaction product of the second step is reacted in a third step with a compound of formula (9) and/or a compound of formula (10)

H-OR⁹(9)

H-OR¹⁰(10)

Wherein R is⁹And R¹⁰Have the meaning defined above.

As cyanuric halide, fluoride, chloride or bromide may be used. Cyanuric chloride is preferred. The reaction may be carried out in an aqueous medium in which the cyanuric halide is suspended in water or an aqueous/organic medium, or dissolved in a solvent such as acetone.

The compounds of formulae (4) and (5) can be added in one of the first or second steps of the preparation process undiluted or in the form of aqueous or organic solvent solutions or in the form of aqueous suspensions. The compounds of the formulae (4) and (5) may be identical compounds, but may also be due to different substituents R⁷、R⁸X, Y and different degrees of substitution m and n. In a particular embodiment, the compounds of formula (4) and (5) are different. For example, the compound of formula (4) may be aniline-4-sulfonic acid, and the compound of formula (5) may be 4-aminotoluene-2-sulfonic acid. If the amines of formulae (4) and (5) are different, they can be reacted simultaneously with cyanuric halide. They may also be reacted in succession with cyanuric halide. If the amines of formulae (4) and (5) are different, they can be reacted simultaneously with cyanuric halide. They may also be reacted in succession with cyanuric halide.

Preferably, the compounds of formulae (4) and (5) are the same, for example 4-aminotoluene-2-sulfonic acid or 3-sulfonic acid-4-ethylaniline. Preferably, the compounds of formulae (4) and (5) are 4-aminotoluene-2-sulfonic acid.

The compound of formula (6) may be added in the first step if the compound of formula (4) and/or (5) is added in the second step, or the compound of formula (6) may be added in the second step when the compound of formula (4) and/or (5) is added in the first step of the preparation process. The compounds of formula (6) may be used in their free acid form or in the form of their salts or as mixed salts. By "free acid" form is meant that M of the diamine of formula (6) represents hydrogen.

The reaction product of the second reaction step is reacted in a third reaction step with an amine of the formulae (7) and (8) or an alcohol of the formulae (9) and (10). The amines of the formulae (7) and (8) or the alcohols of the formulae (9) and (10) can be added without dilution or in aqueous or organic solution or in the form of aqueous suspensions. The compounds of the formulae (7) and (8) may be identical compounds, but may also be due to different substituents R²、R³、R⁴、R⁵But are different from each other. Example (b)For example, the compound of formula (7) is iminodiacetic acid and the compound of formula (8) is diethanolamine. In another embodiment, the compound of formula (7) is diisopropanolamine and the compound of formula (8) is diethanolamine. The compounds of the formulae (9) and (10) may be identical compounds, but may also be due to different substituents R⁹And R¹⁰But are different from each other. For example, the compound of formula (9) is propanol and the compound of formula (10) is methanol. If the compounds of the formulae (7) and (8) or (9) and (10) are different, they can be reacted simultaneously with the reaction product of the second reaction step. They may also be reacted sequentially.

Preferably, the compounds of formulae (7) and (8) are the same, for example diisopropanolamine, diethanolamine or morpholine.

In another preferred embodiment, the compounds of formula (9) and (10) are the same, for example ethanol, preferably methanol.

In one embodiment of the process according to the invention, the reaction step is carried out in an aqueous medium and in the first step the first halogen of the cyanuric halide is substituted by an amine of formula (4) and/or formula (5), the temperature is maintained in the range of from 0 ℃ to 20 ℃ and the pH is maintained in the range of from pH 4 to 6. In the second step, the substitution of the second halogen of the cyanuric halide with the amine of the compound of formula (6) is carried out at a temperature in the range of from 20 to 80 ℃ and the pH is maintained in the range of from pH 6 to 7.5. In the third step, the substitution of the third halogen of the cyanuric halide with an amine of formula (7) and/or formula (8) is carried out at a temperature in the range of 60 ℃ to 102 ℃ and the pH is maintained in the range of pH 7.5 to 9.

The temperature range in each reaction step is maintained by cooling or heating the reaction mixture. The pH can be controlled if desired by adding a suitable acid or base, the preferred acid being hydrochloric acid, sulfuric acid, formic acid or acetic acid, and the preferred base being an alkali metal (lithium, sodium, potassium) hydroxide, carbonate or bicarbonate or an aliphatic tertiary amine, such as triethanolamine or triisopropanolamine. The pH can be monitored throughout the reaction and an appropriate amount of acid or base can be added to the reaction formulation.

The reaction product can be used as such or after desalting using membrane filtration, or the compound of formula (2) according to the invention can be isolated, for example, by precipitation or phase separation.

If Z in the compound of formula (2)¹And Z²Is NR²R³And NR³R₄Then a slight excess of the aliphatic amine of the compounds of formulae (7) and (8) is typically used to promote the desired conversion of the reactants. If Z in the compound of formula (2)¹And Z²Is OR⁹And OR¹⁰Then a large excess of the compounds of formulae (9) and (10) is required.

In general, the compounds of formula (2) according to the invention can be prepared by the known methods for preparing 4, 4 '-diamino-stilbene-2, 2' -disulfonic acid OBAs.

In a fourth aspect, the present invention relates to a method of whitening paper comprising the steps of: providing a pulp suspension, adding 0.01 to 5 wt.%, based on dry fibers of the pulp, of an aqueous composition according to the invention to obtain brightened pulp, draining the pulp of water, pressing and drying the pulp into paper.

In a fifth aspect, the present invention relates to a composition for brightening the surface of paper, comprising or consisting of: at least one surface sizing agent, at least one compound of formula (2) according to the invention as optical brightener, and water.

The surface brightening composition may be from 0.2 to 30g/l, preferably from 1 to 15g/l, most preferably from 2 to 12g/l, based on the total volume of the surface brightening composition.

The surface sizing agent includes one or more starch materials. The surface sizing agent is typically an enzymatically, chemically, or thermally modified starch, such as oxidized, hydroxyethylated, or acetylated starch. The starch may also be a native starch, an anionic starch, a cationic starch, or an amphoteric starch, depending on the particular embodiment being practiced. Although the starch source may be any starch source, examples of starch sources include corn, wheat, potato, rice, tapioca, and sago.

The surface sizing agent is present in the surface brightening composition in an amount of 1 to 30 wt.%, preferably 2 to 20 wt.%, more preferably 5 to 15 wt.%, the wt.% being based on the total weight of the surface brightening composition.

The pH of the surface brightening composition is generally in the range of from 4 to 13, preferably from 6 to 11.

In addition to the surface sizing agent, the compound of formula (2) and water, the surface brightening composition may contain by-products formed during the preparation of the compound of formula (2) of the present invention, as well as other conventional paper additives. Examples of such additives are carriers such as polyvinyl alcohol, antifoaming agents, wax emulsions, dyes, pigments, monovalent metal salts such as sodium chloride, divalent metal salts such as calcium chloride, solubilizing aids, preservatives, complexing agents, crosslinking agents, special resins, and the like.

The surface brightening composition may be applied to the surface of the paper substrate by any surface treatment method known in the art. Examples of application methods include size press application, calender-size application, slot sizing, coating application and spray application (see, e.g., Handbook for Pulp & Paper technologies, 2 nd edition, Angus Wilde publications, 1992, pp 283-. The preferred method of application is at a size press such as an agitated size press or a rod metering size press. The preformed paper sheet is passed through a two-roll nip filled with a sizing composition. The paper absorbs some of the composition and the remainder is removed in the nip.

The paper substrate comprises a cellulosic fibrous web, which may be synthetic or derived from any fibrous plant, including woody and non-woody sources. Preferably, the cellulose fibers are derived from hardwood and/or softwood. The fibers may be virgin fibers or recycled fibers, or any combination of virgin and recycled fibers.

The cellulose fibers contained in the Paper substrate can be modified by physical and/or chemical methods as described, for example, in Handbook for pulp & Paper technologies, 2 nd edition Angus Wilde publication, 1992, chapters 13 and 15, respectively, of g.a. An example of chemical modification of cellulose fibers is the addition of optical brighteners as described, for example, in EP 0884312a1, EP0899373a1, WO 02/055646a1, WO 2006/061399a2, WO 2007/017336a1, WO 2007/143182a2, US 2006/0185808 and US 2007/0193707.

In a sixth aspect, the present invention relates to the preparation of a surface whitening composition by adding at least one compound of formula (2) according to the present invention as optical brightener to a preformed aqueous solution of at least one surface sizing agent at a temperature of 20 ℃ to 90 ℃.

The paper substrate containing the surface brightening composition according to the invention may have any ISO brightness, including an ISO brightness of at least 80, at least 90, or at least 95.

Paper substrates containing the surface brightening composition according to the present invention can have any CIE whiteness, including at least 110, at least 115, at least 120, at least 125, at least 130, at least 135, at least 140, at least 145. The surface brightening composition according to the present invention has a tendency to increase the CIE whiteness of paper compared to conventional surface brightening compositions containing similar levels of optical brightener.

The surface brightening composition according to the invention has a reduced tendency to afforest the paper to which it is applied, greening is a phenomenon related to saturation of the paper, so that the CIE whiteness of the paper does not increase even when the amount of optical brightener is increased, in the CIE L ab system, the tendency to afforest is represented by the a-b diagram, where a and b are the color coordinates.

In a seventh aspect, the present invention relates to a pigmented coating composition for surface brightening of paper comprising or consisting of: at least one pigment, at least one binder and at least one compound of formula (2) according to the invention as optical brightener, and water.

The pigmented coating composition comprises 10 to 70 wt%, preferably 40 to 60 wt% of a white pigment, wherein the wt% is based on the total weight of the pigmented coating composition. Although coating compositions can be produced that do not contain white pigments, the best white substrates for printing are prepared using opaque coating compositions that contain white pigments in the amounts described above.

The white pigment is selected from inorganic pigments, preferably selected from the group consisting of: for example, aluminium silicates (kaolin, otherwise known as china clay), calcium carbonate (chalk), titanium dioxide, aluminium hydroxide, barium carbonate, barium sulphate or calcium sulphate (gypsum) or mixtures thereof. Preferably, a mixture of 10 to 20 wt% clay and 30 to 40 wt% chalk is used as white pigment, wherein the wt% is based on the total weight of the pigmented coating composition. The term "pigment" as used in the context of the present application refers to a water-insoluble compound.

The pigmented coating composition comprises the compound of formula (2) according to the invention in an amount of usually 0.01 to 1% by weight, preferably 0.05 to 0.5% by weight, based on the total weight of the dry white pigment present in the pigmented coating composition.

The binder may be any of those commonly used in the paper industry for producing coating compositions, and may consist of a single binder or a mixture of a first binder and a second binder. The binder is selected from a first binder comprising one or more of a synthetic latex, styrene-butadiene, vinyl acetate, styrene acrylic, vinyl acrylic or ethylene vinyl acetate polymer, and optionally a second binder comprising one or more of starch, carboxymethyl cellulose, casein, soy polymer, polyvinyl alcohol.

The single binder or first binder is preferably a synthetic latex, typically a styrene-butadiene, vinyl acetate, styrene acrylic, vinyl acrylic or ethylene vinyl acetate polymer. The preferred first binder is a latex binder.

The amount of the single binder or first binder is generally from 2 to 25% by weight, preferably from 4 to 20% by weight, based on the total weight of white pigment present in the pigmented coating composition.

The second binder that may optionally be used may be, for example, starch, carboxymethyl cellulose, casein, soy polymers, polyvinyl alcohol, or a mixture thereof. A preferred second binder that may optionally be used is a polyvinyl alcohol binder.

The polyvinyl alcohol which may optionally be used as a second binder in the pigmented coating composition preferably has a degree of hydrolysis of greater than or equal to 60% and a Brookfield viscosity (4% aqueous solution at 20 ℃) of from 2 to 80 mpa.s. More preferably, the polyvinyl alcohol has a degree of hydrolysis greater than or equal to 80% and a Brookfield viscosity (4% aqueous solution at 20 ℃) of between 2 and 40 mPa.s.

When optionally used, the second binder is typically used in an amount of 0.1 to 20 wt.%, preferably 0.2 to 8 wt.%, more preferably 0.3 to 6 wt.%, the wt.% being based on the total weight of white pigment present in the colored coating composition.

The pH of the coating composition is generally in the range of 5 to 13, preferably 6 to 11, more preferably 7 to 10. When it is necessary to adjust the pH of the colored coating composition, an acid or a base may be used. Examples of acids that may be used include, but are not limited to, hydrochloric acid, sulfuric acid, formic acid, and acetic acid. Examples of bases that may be used include, but are not limited to, alkali and alkaline earth metal hydroxides or carbonates, ammonia, or amines.

In addition to the one or more compounds of formula (2), the one or more white pigments, the one or more binders, optionally the one or more secondary binders and water, the coating composition may contain by-products formed during the preparation of the compounds of formula (2) as well as other conventional paper additives. Examples of such additives are, for example, antifreezes, dispersants, synthetic or natural thickeners, carriers, defoamers, wax emulsions, dyes, inorganic salts, solubilizing aids, preservatives, complexing agents, biocides, crosslinkers, pigments, special resins, etc.

The coating composition may be prepared by adding the optical brightener of formula (2) according to the invention to a preformed aqueous dispersion of one or more binders, optionally one or more secondary binders and one or more white pigments.

In an eighth aspect, the present invention relates to a detergent composition for brightening textiles, carpets or natural fibers comprising or consisting of: at least one surfactant and at least one compound of formula (2) according to the invention. The detergent composition may be in liquid or powder form.

The compound of formula (2) may be present in the detergent composition in an amount of from 0.005 to 1.0 wt%, more preferably from 0.01 to 0.5 wt%, most preferably from 0.02 to 0.25 wt%, said wt% being based on the total weight of the detergent composition.

The detergent composition may further comprise

One or more surfactants, which may be anionic or nonionic,

one or more builders, such as alkali metal polyphosphates, sodium carbonate and zeolites, which promote the performance of the surfactants by removing calcium and magnesium ions respectively by complexation, precipitation and ion exchange,

antiredeposition agents, e.g. carboxymethylcellulose and poly (vinylpyrrolidone), and

enzymes, such as proteases, amylases and lipases.

In addition, the detergent composition may also include pH adjusters (typically alkalis), perfumes, shading dyes, anti-microbial agents, bleaches, preservatives, fabric softeners and corrosion inhibitors.

In a ninth aspect, the present invention relates to the use of a compound of formula (2) according to the invention or the use of an aqueous composition according to the invention for optical brightening of textiles, paper, cardboard and nonwovens. The compounds of the formula (2) are particularly suitable as optical brighteners for brightening and whitening paper, paperboard and nonwovens.

A preferred use of the compound of formula (2) according to the invention is as an additive in a papermaking process, wherein the compound of formula (2) is added to the pulp.

Another preferred use of the compounds of formula (2) according to the invention is in the compositions for the lightening of paper surfaces according to the invention or in the pigmented coating compositions according to the invention or in the detergent compositions according to the invention.