CA2636234A1 - Process for producing optically brightened paper - Google Patents
Process for producing optically brightened paper Download PDFInfo
- Publication number
- CA2636234A1 CA2636234A1 CA002636234A CA2636234A CA2636234A1 CA 2636234 A1 CA2636234 A1 CA 2636234A1 CA 002636234 A CA002636234 A CA 002636234A CA 2636234 A CA2636234 A CA 2636234A CA 2636234 A1 CA2636234 A1 CA 2636234A1
- Authority
- CA
- Canada
- Prior art keywords
- optically brightened
- fibres
- process according
- paper
- pulp
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
- D21H21/30—Luminescent or fluorescent substances, e.g. for optical bleaching
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H3/00—Paper or cardboard prepared by adding substances to the pulp or to the formed web on the paper-making machine and by applying substances to finished paper or cardboard (on the paper-making machine), also when the intention is to impregnate at least a part of the paper body
- D21H3/82—Paper or cardboard prepared by adding substances to the pulp or to the formed web on the paper-making machine and by applying substances to finished paper or cardboard (on the paper-making machine), also when the intention is to impregnate at least a part of the paper body by adding insoluble coloured substances, e.g. powders, fibres, pieces of metal, for obtaining different colours in the paper fancy papers; substances characterised by their physical appearance, e.g. form, rather than by their chemical constitution
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/10—Organic non-cellulose fibres
- D21H13/12—Organic non-cellulose fibres from macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D21H13/14—Polyalkenes, e.g. polystyrene polyethylene
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/10—Organic non-cellulose fibres
- D21H13/20—Organic non-cellulose fibres from macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- D21H13/24—Polyesters
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/10—Organic non-cellulose fibres
- D21H13/20—Organic non-cellulose fibres from macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- D21H13/26—Polyamides; Polyimides
Abstract
The instant invention relates to a process for the production of optically brightened paper by treating the pulp suspension with an optically brightened filler composition comprising optically brightened plastic fibres, preferably polyester fibres, which leads to a surprising high lightfastness of the resulting paper.
Description
PROCESS FOR PRODUCING OPTICALLY BRIGHTENED PAPER
The present invention relates to a process for the production of optically brightened paper by treating the pulp suspension with an optically brightened filler composition.
A high degree of brightness is a desirable property of paper and cardboard articles.
The most important raw material of the papermaking industry is pulp, which naturally absorbs blue light and therefore is yellowish in color and imparts a dull appearance to the paper. Optical brighteners are used in the papermaking industry to compensate for the absorption of blue light by absorbing UV-Iight with a maximum wavelength of 350-380nm and converting it into visible blue light with a maximum wavelength of 440nm.
Optical brighteners of the triazinylaminostilbene type have been used almost exclusively to brighten paper either by application to pulp or to the paper surface. It is well-known however that the lightfastness of brighteners of this type is no better than poor to moderate, or I to approximately 3 on the "Blue Wool Scale". (See "Optische Aufheller - neuere Erkenntnisse zu Eigenschaften und Verhalten im Papier" by F.
Muller, D. Loewe and B. Hunke in Wochenblatt fur Papierfabrikation 1991, 6, pages 191-203.) There is therefore a demand to protect optically brightened papers from yellowing in light.
In order to provide optically brightened papers of high lightfastness, it is generally recognized that brighteners other than those of the triazinylaminostilbene type must be used; in particular, brighteners typically used for the optical brightening of textiles, such as those of the benzoxazole, naphthalimide, triazolylcoumarin or triazinylpyrene types.
Such brighteners are however typically much more expensive, and can only be applied with difficulty to either pulp or to the paper surface.
EP-A-801 700 overcomes some of these problems by describing the use of optically brightened polyacrylonitrile powder to prepare white coating slips for paper.
Preferred optical brighteners are those typically used to provide a high lightfastness on textiles, for example of the triazolylcoumarin or benzoxazole type. Papers prepared using such coating slips show excellent whitening effects with high lightfastness. There is no suggestion however that this approach could be used to prepare optically brightened papers by a more economic pulp application.
The present invention relates to a process for the production of optically brightened paper by treating the pulp suspension with an optically brightened filler composition.
A high degree of brightness is a desirable property of paper and cardboard articles.
The most important raw material of the papermaking industry is pulp, which naturally absorbs blue light and therefore is yellowish in color and imparts a dull appearance to the paper. Optical brighteners are used in the papermaking industry to compensate for the absorption of blue light by absorbing UV-Iight with a maximum wavelength of 350-380nm and converting it into visible blue light with a maximum wavelength of 440nm.
Optical brighteners of the triazinylaminostilbene type have been used almost exclusively to brighten paper either by application to pulp or to the paper surface. It is well-known however that the lightfastness of brighteners of this type is no better than poor to moderate, or I to approximately 3 on the "Blue Wool Scale". (See "Optische Aufheller - neuere Erkenntnisse zu Eigenschaften und Verhalten im Papier" by F.
Muller, D. Loewe and B. Hunke in Wochenblatt fur Papierfabrikation 1991, 6, pages 191-203.) There is therefore a demand to protect optically brightened papers from yellowing in light.
In order to provide optically brightened papers of high lightfastness, it is generally recognized that brighteners other than those of the triazinylaminostilbene type must be used; in particular, brighteners typically used for the optical brightening of textiles, such as those of the benzoxazole, naphthalimide, triazolylcoumarin or triazinylpyrene types.
Such brighteners are however typically much more expensive, and can only be applied with difficulty to either pulp or to the paper surface.
EP-A-801 700 overcomes some of these problems by describing the use of optically brightened polyacrylonitrile powder to prepare white coating slips for paper.
Preferred optical brighteners are those typically used to provide a high lightfastness on textiles, for example of the triazolylcoumarin or benzoxazole type. Papers prepared using such coating slips show excellent whitening effects with high lightfastness. There is no suggestion however that this approach could be used to prepare optically brightened papers by a more economic pulp application.
The economic use of textile brighteners to prepare optically brightened papers is therefore a difficult problem to which a satisfactory solution has not yet been found.
Surprisingly, it has now been found that by treating a pulp suspension with a filler composition comprising finely divided optically brightened plastic fibres, an optically brightened paper of high lightfastness is obtained in an economic manner.
Therefore an object of the instant invention is a process for optical brightening of paper wherein a filler composition comprising optically brightened plastic fibres is added to the pulp suspension.
Said fibres preferably can be made from polyester, polyethylene, polypropylene or polyamide. Most preferably the fibres are made from polyester.
The fibres have a fineness between 1 and 10 dtex and are cut to a length of between 0.1 and 1 mm, preferably they have a fineness between 1 and 2 dtex and a length between 0.2 and 0.6mm.
The preparation of polyester fibres is well-known and is described, for example, in "Handbook of Fiber Chemistry" by Menachem Lewin published in 1998 by Marcel Dekker, page 18.
The production of optically brightened polyester is equally well-known and is described, for example, in GB 835,898 and EP-A-1 379 585.
For the purpose of the present invention, the fibres are preferably optically brightened with compounds of formulae (1) to (4) R4 R5 (1) I_;_I /A----~
Ri Rs (CI-C4)AlkyI (2) O N O
I \ \
0-(C1-C4)AlkyI
(3) / \ \
N, N O O
N
O (C1-C4)Alkyl (4) N
N ~>-O-(C1-C4)AlkyI
- -N
where in formula (1) R, to R$ independently of one another are hydrogen, C,-C20-alkyl or groups of the formula -COOR9, where R9 is hydrogen, Cl-C2o-alkyl or phenyl, or R, to R8 are a group of the formula -S02R,o, where R,o is hydrogen, C,-Clo-alkyl or C,-Clo-hydroxyalkyl, and A is stilbene, naphthalene, phenylene, thiophenylene or biphenylene, or mixtures of said compounds.
More preferred optical brighteners are compounds of formula (1) where R, to R8 independently of one another are hydrogen or C,-C4-alkyl, and A is stilbene, naphthalene, phenylene, thiophenylene or biphenylene.
Most preferred optical brighteners are compounds of formula (1) where R, to R8 independently of one another are hydrogen or methyl, and A is stilbene.
Surprisingly, it has now been found that by treating a pulp suspension with a filler composition comprising finely divided optically brightened plastic fibres, an optically brightened paper of high lightfastness is obtained in an economic manner.
Therefore an object of the instant invention is a process for optical brightening of paper wherein a filler composition comprising optically brightened plastic fibres is added to the pulp suspension.
Said fibres preferably can be made from polyester, polyethylene, polypropylene or polyamide. Most preferably the fibres are made from polyester.
The fibres have a fineness between 1 and 10 dtex and are cut to a length of between 0.1 and 1 mm, preferably they have a fineness between 1 and 2 dtex and a length between 0.2 and 0.6mm.
The preparation of polyester fibres is well-known and is described, for example, in "Handbook of Fiber Chemistry" by Menachem Lewin published in 1998 by Marcel Dekker, page 18.
The production of optically brightened polyester is equally well-known and is described, for example, in GB 835,898 and EP-A-1 379 585.
For the purpose of the present invention, the fibres are preferably optically brightened with compounds of formulae (1) to (4) R4 R5 (1) I_;_I /A----~
Ri Rs (CI-C4)AlkyI (2) O N O
I \ \
0-(C1-C4)AlkyI
(3) / \ \
N, N O O
N
O (C1-C4)Alkyl (4) N
N ~>-O-(C1-C4)AlkyI
- -N
where in formula (1) R, to R$ independently of one another are hydrogen, C,-C20-alkyl or groups of the formula -COOR9, where R9 is hydrogen, Cl-C2o-alkyl or phenyl, or R, to R8 are a group of the formula -S02R,o, where R,o is hydrogen, C,-Clo-alkyl or C,-Clo-hydroxyalkyl, and A is stilbene, naphthalene, phenylene, thiophenylene or biphenylene, or mixtures of said compounds.
More preferred optical brighteners are compounds of formula (1) where R, to R8 independently of one another are hydrogen or C,-C4-alkyl, and A is stilbene, naphthalene, phenylene, thiophenylene or biphenylene.
Most preferred optical brighteners are compounds of formula (1) where R, to R8 independently of one another are hydrogen or methyl, and A is stilbene.
The optically brightened plastic fibre contains between 10 and 500 ppm optical brightener, preferably between 20 and 250 ppm.
The pulp may be any conventional pulp used to produce paper, for example stone groundwood pulp, thermomechanical pulp, chemithermomechanical pulp, semichemical pulp, sulphite pulp or kraft pulp, or a mixture of these.
In general the pulp suspension is treated with 2 to 60%, preferably 10 to 40%
by weight, based on weight of dry pulp, of the instant filler composition.
The filler composition may be added to the pulp suspension either in dry form or, preferably, in the form of an aqueous dispersion. It may be useful to add a dispersing agent, particularly suitable dispersing agents being of the type described in 015. Finally, the paper is formed on a wire screen of a conventional paper machine, pressed and dried.
The present invention also provides an optically brightened paper produced according to the instant process and which comprises 2 to 60%, preferably 10 to 40% by weight, based on weight of dry pulp, of the filler composition of the instant invention.
The optically brightened paper may also contain other additives commonly employed in the papermaking industry. Examples of such additives include sizing agents (for example, rosin, starch, alkyl ketene dimer, alkenyl succinic anhydride), wet strength resins (for example, poly-aminoamide-epichlorohydrin resins), retention- and drainage aids (for example, poly-aluminium chloride, polydiallyldimethylammonium chloride), and shading dyes.
The following example further serves to illustrate the invention. All parts and all percentages are by weight, unless indicated to the contrary.
EXAMPLE
The pulp may be any conventional pulp used to produce paper, for example stone groundwood pulp, thermomechanical pulp, chemithermomechanical pulp, semichemical pulp, sulphite pulp or kraft pulp, or a mixture of these.
In general the pulp suspension is treated with 2 to 60%, preferably 10 to 40%
by weight, based on weight of dry pulp, of the instant filler composition.
The filler composition may be added to the pulp suspension either in dry form or, preferably, in the form of an aqueous dispersion. It may be useful to add a dispersing agent, particularly suitable dispersing agents being of the type described in 015. Finally, the paper is formed on a wire screen of a conventional paper machine, pressed and dried.
The present invention also provides an optically brightened paper produced according to the instant process and which comprises 2 to 60%, preferably 10 to 40% by weight, based on weight of dry pulp, of the filler composition of the instant invention.
The optically brightened paper may also contain other additives commonly employed in the papermaking industry. Examples of such additives include sizing agents (for example, rosin, starch, alkyl ketene dimer, alkenyl succinic anhydride), wet strength resins (for example, poly-aminoamide-epichlorohydrin resins), retention- and drainage aids (for example, poly-aluminium chloride, polydiallyldimethylammonium chloride), and shading dyes.
The following example further serves to illustrate the invention. All parts and all percentages are by weight, unless indicated to the contrary.
EXAMPLE
5 parts polyester fibres of fineness 1.7 dtex made by known methods, containing 0.014% of a mixture of optical brighteners of structures 5a-c in an approximate ratio of 30:50:20, and cut to 0.5 mm, are stirred with 0.025 parts dispersing agent 5 (Cartaspers PSM, commercially available from Clariant) and 1000 parts water for 5 minutes to form a 0.5% dispersion of optically brightened fibres.
0 _ (5a) C N X
N
u 0 _ (5b) CN \ / \ j CH3 o ~
o (5c) j :( ::: C
/>-H N
C
3 O x parts of the 0.5% dispersion of optically brightened fibres are then added to (1 000-x) parts of a stirred 0.5% aqueous suspension of a 50:50 mixture of bleached birch and spruce wood pulps beaten to a Schopper-Riegler freeness of 35 . A paper sheet is then made by drawing the dispersed suspension through a wire mesh. After being pressed and dried, the optically brightened paper contains between 5% (x = 50) and 30% (x = 300) optically brightened polyester fibres, equivalent to an optical brightener content of between 7 ppm and 42 ppm.
Each paper sheet is measured for R457 Brightness on a calibrated Minolta 3270D
spectrophotometer.
Accelerated ageing experiments are conducted by exposing the papers in a Xenotest apparatus. R457 Brightness measurements are made at intervals of 70, 140 and hours. The results are shown below in tabular (Table 1) and graphical (Fig 1) forms.
0 _ (5a) C N X
N
u 0 _ (5b) CN \ / \ j CH3 o ~
o (5c) j :( ::: C
/>-H N
C
3 O x parts of the 0.5% dispersion of optically brightened fibres are then added to (1 000-x) parts of a stirred 0.5% aqueous suspension of a 50:50 mixture of bleached birch and spruce wood pulps beaten to a Schopper-Riegler freeness of 35 . A paper sheet is then made by drawing the dispersed suspension through a wire mesh. After being pressed and dried, the optically brightened paper contains between 5% (x = 50) and 30% (x = 300) optically brightened polyester fibres, equivalent to an optical brightener content of between 7 ppm and 42 ppm.
Each paper sheet is measured for R457 Brightness on a calibrated Minolta 3270D
spectrophotometer.
Accelerated ageing experiments are conducted by exposing the papers in a Xenotest apparatus. R457 Brightness measurements are made at intervals of 70, 140 and hours. The results are shown below in tabular (Table 1) and graphical (Fig 1) forms.
% Brightened R457 Brightness R457 Brightness R457 Brightness R457 Brightness fibres in paper before exposure after 70h after 140h after 280h 0 82.6 83.6 84.3 85.9 84.0 85.0 85.3 86.3 86.1 86.6 86.6 88.0 88.0 88.6 88.6 89.3 89.0 89.5 89.3 90.1 91.0 91.6 91.3 91.7 91.4 92.0 91.8 92.3 92 - - - -~
~ ~ ~ - -- - - . --_~.__-- -------~---U) 30 ia ------------------~ @0 ---------- --- ------------- ~- - ---~-_.~ ,o --o---25%
~p A--- L0%
---------- - -a ~ _ .-A
(Y) 1 ` a _---= ~ -~- 10%
--- --0 50 100 150 200 250 Si.:19~
~ Xposure time in hours 5 Fig 1: Effect of exposure to light over 280 hours on R457 Brightness of papers containing 5-30% optically brightened polyester fibres.
It is clear from the results that the present invention provides an optically brightened paper of high lightfastness, with the additional advantage that a surprisingly low 10 concentration (7-42 ppm) of optical brightener is required to achieve a high degree of brightness.
~ ~ ~ - -- - - . --_~.__-- -------~---U) 30 ia ------------------~ @0 ---------- --- ------------- ~- - ---~-_.~ ,o --o---25%
~p A--- L0%
---------- - -a ~ _ .-A
(Y) 1 ` a _---= ~ -~- 10%
--- --0 50 100 150 200 250 Si.:19~
~ Xposure time in hours 5 Fig 1: Effect of exposure to light over 280 hours on R457 Brightness of papers containing 5-30% optically brightened polyester fibres.
It is clear from the results that the present invention provides an optically brightened paper of high lightfastness, with the additional advantage that a surprisingly low 10 concentration (7-42 ppm) of optical brightener is required to achieve a high degree of brightness.
COIVIPA TIVE EXAMPLES
Comparative Example 1: Brightened polyester fibres A paper sheet is made as in the Example, containing 25% (x = 250) optically brightened polyester fibres.
Comparative Example 2: Unbrightened pulp A paper sheet is made as in the Example, but without the addition of optically brightened polyester fibres.
Comparative Example 3: Unbrightened polyester fibres A paper sheet is made as in the Example, but containing 25% (x = 250) unbrightened polyester fibres in place of the optically brightened polyester fibres.
Comparative Example 4: Unbrightened polyester fibres and optical brightener (5a-c) A paper sheet is made as in the Example, but containing 25% (x = 250) unbrightened polyester fibres and - added separately to the 1000 parts of 0.5% aqueous suspension of fibres - 0.000175 parts of a mixture of optical brighteners of structures (5a-c) in an approximate ratio of 30:50:20, all in place of the optically brightened polyester fibres.
Comparative Example 5: Unbrightened polyester fibres and optical brightener (6) HO H - (6) N ~ ~ S03Na N-C~ ~ N
N - NaO3S
HO H ~ ~ \ N OH
SO3Na N
N ~-N
N
NaO3S H
OH
A paper sheet is made as in the Example, but containing 25% (x = 250) unbrightened polyester fibres and - added separately to the 1000 parts of 0.5% aqueous suspension of fibres - 0.004 parts of an optical brightener of structure (6), all in place of the optically brightened polyester fibres.
Accelerated ageing experiments are conducted as in the Example. The results are shown below in tabular (Table 2) and graphical (Fig 2) forms.
Comparative R457 Brightness R457 Brightness R457 Brightness R457 Brightness Example before exposure after 70h after 140h after 280h 1 92.1 93.0 92.9 92.7 2 83.8 85.6 86.5 87.5 3 85.3 87.0 87.7 88.5 4 85.5 87.1 87.8 88.4 5 97.5 90.5 88.7 87.5 ~
a) ~---- --- 0 --_-- --------~ -~- Compar<{dve Examp[e 1 -- s~ Cc. qrara'aveExarnple 2 g0 -Gu -~caraWe Examp[~ 3 rTA ~^`_ 4-a _-- -~-Cc ;~ arativeExarnpIe 4 ~
LO . - ¾ __ - - ^ = rcm urativeExamp~~ 5 10 Exposure 'Llllne !n hours Fig 2: Effect of exposure to light over 280 hours on R457 Brightness of papers.
The Comparative Examples demonstrate the advantage of the invention in providing a bright paper with excellent lightfastness.
It is clear that the addition of optically brightened polyester fibres (Comparative Example 1) gives a much brighter paper than does the addition of unbrightened polyester fibres (Comparative Example 3). It is equally clear that the optical brightener must be incorporated into the polyester fibre, rather than added separately (Comparative Example 4). Whereas the separate addition of an optical brightener (6) of the triazinylaminostilbene type gives a particularly bright paper, the lightfastness of said paper is poor (Comparative Example 5).
Comparative Example 1: Brightened polyester fibres A paper sheet is made as in the Example, containing 25% (x = 250) optically brightened polyester fibres.
Comparative Example 2: Unbrightened pulp A paper sheet is made as in the Example, but without the addition of optically brightened polyester fibres.
Comparative Example 3: Unbrightened polyester fibres A paper sheet is made as in the Example, but containing 25% (x = 250) unbrightened polyester fibres in place of the optically brightened polyester fibres.
Comparative Example 4: Unbrightened polyester fibres and optical brightener (5a-c) A paper sheet is made as in the Example, but containing 25% (x = 250) unbrightened polyester fibres and - added separately to the 1000 parts of 0.5% aqueous suspension of fibres - 0.000175 parts of a mixture of optical brighteners of structures (5a-c) in an approximate ratio of 30:50:20, all in place of the optically brightened polyester fibres.
Comparative Example 5: Unbrightened polyester fibres and optical brightener (6) HO H - (6) N ~ ~ S03Na N-C~ ~ N
N - NaO3S
HO H ~ ~ \ N OH
SO3Na N
N ~-N
N
NaO3S H
OH
A paper sheet is made as in the Example, but containing 25% (x = 250) unbrightened polyester fibres and - added separately to the 1000 parts of 0.5% aqueous suspension of fibres - 0.004 parts of an optical brightener of structure (6), all in place of the optically brightened polyester fibres.
Accelerated ageing experiments are conducted as in the Example. The results are shown below in tabular (Table 2) and graphical (Fig 2) forms.
Comparative R457 Brightness R457 Brightness R457 Brightness R457 Brightness Example before exposure after 70h after 140h after 280h 1 92.1 93.0 92.9 92.7 2 83.8 85.6 86.5 87.5 3 85.3 87.0 87.7 88.5 4 85.5 87.1 87.8 88.4 5 97.5 90.5 88.7 87.5 ~
a) ~---- --- 0 --_-- --------~ -~- Compar<{dve Examp[e 1 -- s~ Cc. qrara'aveExarnple 2 g0 -Gu -~caraWe Examp[~ 3 rTA ~^`_ 4-a _-- -~-Cc ;~ arativeExarnpIe 4 ~
LO . - ¾ __ - - ^ = rcm urativeExamp~~ 5 10 Exposure 'Llllne !n hours Fig 2: Effect of exposure to light over 280 hours on R457 Brightness of papers.
The Comparative Examples demonstrate the advantage of the invention in providing a bright paper with excellent lightfastness.
It is clear that the addition of optically brightened polyester fibres (Comparative Example 1) gives a much brighter paper than does the addition of unbrightened polyester fibres (Comparative Example 3). It is equally clear that the optical brightener must be incorporated into the polyester fibre, rather than added separately (Comparative Example 4). Whereas the separate addition of an optical brightener (6) of the triazinylaminostilbene type gives a particularly bright paper, the lightfastness of said paper is poor (Comparative Example 5).
Claims (14)
1. Process for optical brightening of paper wherein a filler composition comprising optically brightened plastic fibres is added to the pulp suspension.
2. Process according to claim 1 wherein the fibres are made from polyester, polyethylene, polypropylene or polyamide.
3. Process according to claim 2 wherein the fibres are made from polyester.
4. Process according to claim 3 wherein the fibres have a fineness between 1 and dtex and are cut to a length of between 0.1 and 1 mm.
5. Process according to claim 4 wherein the fibres have a fineness between 1 and 2 dtex and are cut to a length of between 0.2 and 0.6 mm.
6. Process according to any of the preceding claims wherein the fibres are optically brightened with compounds of formulae (1) to (4) and where in formula (1) R1 to R8 independently of one another are hydrogen, C1-C20-alkyl or groups of the formula -COOR9, R9 is hydrogen, C1-C20-alkyl or phenyl, or R1 to R8 are a group of the formula -SO2R10, where R10 is hydrogen, C1-C10-alkyl or C1-C10-hydroxyalkyl, and A is stilbene, naphthalene, phenylene, thiophenylene or biphenylene, or mixtures of said compounds.
7. Process according to claim 6 wherein the fibres are optically brightened with a compound of formula (1) wherein R1 to R8 independently of one another are hydrogen or C1-C4-alkyl, and A is stilbene, naphthalene, phenylene, thiophenylene or biphenylene.
8. Process according to claim 7 wherein R1 to R8 independently of one another are hydrogen or methyl, and A is stilbene.
9. Process according to any of claims 2 to 8 wherein the optically brightened plastic fibres contain between 10 and 500 ppm optical brightener.
10. Process according to claim 9 wherein the optically brightened plastic fibres contain between 20 and 250 ppm optical brightener.
11. Process according to any of the preceding claims wherein 2 to 60 % by weight, based on the weight of the dry pulp, of the optically brightened filler composition is added to the pulp suspension.
12. Process according to claim 11 wherein 10 to 40 % by weight, based on the weight of the dry pulp, of the optically brightened filler composition is added to the pulp suspension.
13. Process according to claims 11 or 12 wherein the optically brightened filler composition is added to the pulp suspension in the form of an aqueous dispersion.
14. Optically brightened paper produced by a process according to any of the preceding claims.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP06001577.3 | 2006-01-26 | ||
| EP06001577 | 2006-01-26 | ||
| PCT/EP2006/070148 WO2007085337A1 (en) | 2006-01-26 | 2006-12-22 | Process for producing optically brightened paper |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2636234A1 true CA2636234A1 (en) | 2007-08-02 |
Family
ID=36636660
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002636234A Abandoned CA2636234A1 (en) | 2006-01-26 | 2006-12-22 | Process for producing optically brightened paper |
Country Status (17)
| Country | Link |
|---|---|
| US (1) | US20100230061A1 (en) |
| EP (1) | EP1982017B1 (en) |
| JP (1) | JP2009524747A (en) |
| KR (1) | KR20080095862A (en) |
| CN (1) | CN101365843A (en) |
| AR (1) | AR059215A1 (en) |
| AT (1) | ATE434083T1 (en) |
| AU (1) | AU2006336948A1 (en) |
| BR (1) | BRPI0621286A2 (en) |
| CA (1) | CA2636234A1 (en) |
| DE (1) | DE602006007388D1 (en) |
| IL (1) | IL192985A0 (en) |
| NO (1) | NO20083311L (en) |
| RU (1) | RU2008134714A (en) |
| TW (1) | TW200738936A (en) |
| WO (1) | WO2007085337A1 (en) |
| ZA (1) | ZA200806504B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2906611A1 (en) * | 2012-10-10 | 2015-08-19 | Invista Technologies S.A R.L. | Polyamide compositions and processes |
Family Cites Families (26)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB835898A (en) * | 1955-06-17 | 1960-05-25 | Ciba Ltd | New ª:ª-di-[benzoxazolyl-(2)]-ethylenes |
| US3342921A (en) * | 1966-03-16 | 1967-09-19 | West Virginia Pulp & Paper Co | Process for producing fibrous filler having high wet end retention |
| US3597312A (en) * | 1969-05-07 | 1971-08-03 | Westvaco Corp | Synthetic fibrous filler and paper containing the filler |
| BE755820A (en) * | 1969-09-12 | 1971-03-08 | Sandoz Sa | COMPOSITION OF OPTICAL BLEACH |
| US3871898A (en) * | 1969-11-14 | 1975-03-18 | Ciba Geigy Ag | Process for the optical brightening of organic fibre material |
| US3775353A (en) * | 1971-11-05 | 1973-11-27 | Westvaco Corp | Blushed polystyrene pigment |
| DE2420473A1 (en) * | 1974-04-27 | 1975-12-11 | Bayer Ag | WHITE TONES OF POLYESTER FIBERS |
| US3983288A (en) * | 1974-11-04 | 1976-09-28 | Eastman Kodak Company | Fibers and fabrics containing optical brightening agents |
| DE2500915C3 (en) * | 1975-01-11 | 1980-09-18 | Bayer Ag, 5090 Leverkusen | Process for tinting textile fibers made of polyesters or mixed fibers of polyesters and cellulose or wool white |
| US4095939A (en) * | 1977-05-09 | 1978-06-20 | Eastman Kodak Company | Optically brightened polyesters with 2,5-bis-(p-carboalkylstyryl)-oxadiazole |
| US4460647A (en) * | 1982-09-13 | 1984-07-17 | Celanese Corporation | Fibrets suitable for paper opacification |
| US4859539A (en) * | 1987-03-23 | 1989-08-22 | Eastman Kodak Company | Optically brightened polyolefin coated paper support |
| ES2029345T3 (en) * | 1987-08-26 | 1992-08-01 | Ciba-Geigy Ag | OPTICAL DISPERSION BLEACHERS. |
| US5213883A (en) * | 1991-05-14 | 1993-05-25 | The Mead Corporation | Decor sheet containing fibrets |
| DE4230655A1 (en) * | 1992-09-14 | 1994-03-17 | Ciba Geigy | Process for improving the whiteness, brightness and color location of fibrous materials |
| DE19500195A1 (en) * | 1995-01-05 | 1996-07-11 | Bayer Ag | Use of white-tinted plastics for tinting paper coating slips and such white-tinted paper coating slips |
| US5759349A (en) * | 1995-12-14 | 1998-06-02 | Westvaco Corporation | Lumen loading of hygienic end use paper fibers |
| NZ331438A (en) * | 1997-09-16 | 2000-01-28 | Ciba Sc Holding Ag | A method of increasing the whiteness of paper by using a formulation containing a swellale layered silicate and an optical brightener 4,4-bis-(triazinylamino)-stilbene-2,2-disulphonic acid |
| DE10114696A1 (en) * | 2001-03-23 | 2002-11-07 | Clariant Gmbh | Process for the production of optically brightened polyester |
| US6893473B2 (en) * | 2002-05-07 | 2005-05-17 | Weyerhaeuser.Company | Whitened fluff pulp |
| DE10237186A1 (en) * | 2002-08-14 | 2004-03-18 | Clariant Gmbh | Process for lightening synthetic fibers and plastics with granulated optical brighteners |
| US6818367B2 (en) * | 2003-04-15 | 2004-11-16 | Eastman Kodak Company | Support with reduced optical brightener migration |
| US20040260034A1 (en) * | 2003-06-19 | 2004-12-23 | Haile William Alston | Water-dispersible fibers and fibrous articles |
| DE102004011957A1 (en) * | 2004-03-11 | 2005-09-29 | Basf Ag | Process for the optical whitening of synthetic fibers or of synthetic fibers mixed with natural fibers |
| US7638016B2 (en) * | 2005-02-19 | 2009-12-29 | International Paper Company | Method for treating kraft pulp with optical brighteners after chlorine bleaching to increase brightness |
| US7622022B2 (en) * | 2006-06-01 | 2009-11-24 | Benny J Skaggs | Surface treatment of substrate or paper/paperboard products using optical brightening agent |
-
2006
- 2006-12-22 AU AU2006336948A patent/AU2006336948A1/en not_active Abandoned
- 2006-12-22 DE DE602006007388T patent/DE602006007388D1/en not_active Expired - Fee Related
- 2006-12-22 JP JP2008551681A patent/JP2009524747A/en active Pending
- 2006-12-22 KR KR1020087018263A patent/KR20080095862A/en not_active Application Discontinuation
- 2006-12-22 WO PCT/EP2006/070148 patent/WO2007085337A1/en active Application Filing
- 2006-12-22 EP EP06830803A patent/EP1982017B1/en not_active Not-in-force
- 2006-12-22 US US12/223,267 patent/US20100230061A1/en not_active Abandoned
- 2006-12-22 BR BRPI0621286-7A patent/BRPI0621286A2/en not_active Application Discontinuation
- 2006-12-22 RU RU2008134714/12A patent/RU2008134714A/en unknown
- 2006-12-22 CA CA002636234A patent/CA2636234A1/en not_active Abandoned
- 2006-12-22 AT AT06830803T patent/ATE434083T1/en not_active IP Right Cessation
- 2006-12-22 CN CNA200680051825XA patent/CN101365843A/en active Pending
-
2007
- 2007-01-24 TW TW096102710A patent/TW200738936A/en unknown
- 2007-01-26 AR ARP070100354A patent/AR059215A1/en unknown
-
2008
- 2008-07-23 IL IL192985A patent/IL192985A0/en unknown
- 2008-07-25 NO NO20083311A patent/NO20083311L/en not_active Application Discontinuation
- 2008-07-25 ZA ZA200806504A patent/ZA200806504B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| ATE434083T1 (en) | 2009-07-15 |
| RU2008134714A (en) | 2010-03-10 |
| TW200738936A (en) | 2007-10-16 |
| KR20080095862A (en) | 2008-10-29 |
| AR059215A1 (en) | 2008-03-19 |
| JP2009524747A (en) | 2009-07-02 |
| EP1982017B1 (en) | 2009-06-17 |
| DE602006007388D1 (en) | 2009-07-30 |
| IL192985A0 (en) | 2009-02-11 |
| EP1982017A1 (en) | 2008-10-22 |
| NO20083311L (en) | 2008-10-27 |
| CN101365843A (en) | 2009-02-11 |
| WO2007085337A1 (en) | 2007-08-02 |
| AU2006336948A1 (en) | 2007-08-02 |
| ZA200806504B (en) | 2009-11-25 |
| US20100230061A1 (en) | 2010-09-16 |
| BRPI0621286A2 (en) | 2011-12-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0561828B1 (en) | Paper and a method of paper manufacture | |
| US8871054B2 (en) | Process for preparing fluff pulp sheet with cationic dye and debonder surfactant | |
| AU2006235427B2 (en) | Improved composition and processes for paper production | |
| KR100952554B1 (en) | Improvements relating to optical brighteners | |
| CA2910585C (en) | Use of micronized cellulose and fluorescent whitening agent for surface treatment of cellulosic materials | |
| CA2789548C (en) | Aqueous sizing compositions for shading in size press applications | |
| KR20110007604A (en) | Improved optical brightening compositions | |
| PL201227B1 (en) | Decorative substrate paper and decorative paper | |
| CA2636234A1 (en) | Process for producing optically brightened paper | |
| JP5365898B2 (en) | Newspaper production method and newsprint | |
| CA2713268A1 (en) | A method for production of paper | |
| TWM581605U (en) | Fluorescent-free paper | |
| WO2017198694A1 (en) | Fluorescent whitening agents and mixtures thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |