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
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06L—DRY-CLEANING, WASHING OR BLEACHING FIBRES, FILAMENTS, THREADS, YARNS, FABRICS, FEATHERS OR MADE-UP FIBROUS GOODS; BLEACHING LEATHER OR FURS
  • D06L4/00—Bleaching fibres, filaments, threads, yarns, fabrics, feathers or made-up fibrous goods; Bleaching leather or furs
  • D06L4/60—Optical bleaching or brightening
  • D06L4/664—Preparations of optical brighteners; Optical brighteners in aerosol form; Physical treatment of optical brighteners

Definitions

• liquid aqueous brightener preparations which, in addition to an optical brightener of the diaminostilbenedisulfonic acid series, contain a solubilizer which, inter alia, can be a "not too high molecular weight" polyglycol ether; In example 5 of this patent, polyethylene glycol 400 is used.
• a solubilizer which, inter alia, can be a "not too high molecular weight" polyglycol ether
• polyethylene glycol 400 is used.
• British Patent 1,391,593 describes aqueous paper coating slips which, in addition to a water-soluble optical brightener of the diaminostilbenedisulfonic acid series, contain a polyethylene glycol, in particular a polyethylene glycol 4000, and certain methylated polymethylolmelamine / urea resins in addition to a synthetic latex and a dispersed white pigment.
• German patent specifications 21 45 384 and 24 30 624 describe aqueous paper coating slips which, in addition to a water-soluble optical brightener for the diaminostilbenedisulfonic acid series, white pigment and binder, contain a polyethylene glycol 5000-6000 and the paper is coated with these coating slips; In this way, high white effects can be achieved in the paper coating.
• the additives described in these three patents, in particular the brightener and the polyethylene glycol, are individually added to the paper coating slips.
• aqueous brightener preparations which are distinguished by a surprisingly good stability and can be prepared which paper coating, in particular paper coating containing a synthetic latex, can be surprisingly well brightened optically, the formulation and preparation of the paper coating slips being particularly simple and efficient using the liquid brightener preparations.
• the invention thus relates to the corresponding brightener preparations and their use for optically brightening paper coating or for producing coated paper, at least the coating being optically brightened.
• the compounds of formula (I) are known as such and also as optical brighteners.
• Preferred compounds of the formula (I) are those in which R 3 is hydrogen, ⁇ -hydroxyethyl, ⁇ -hydroxypropyl, methyl, ethyl, ⁇ -cyanoethyl or ⁇ -carbamoylethyl and R 4 is ⁇ -hydroxyethyl, ⁇ -hydroxypropyl or ⁇ ( ß'-Hydroxy-ethoxy) ethyl means or R 3 and R 4 together with the adjacent nitrogen atom means a morpholino radical.
• a uniform optical brightener is used as component (a), then this is preferably as defined under (a l ), in particular one in which R 1 is hydrogen; if component (a) is a mixture of brighteners, then it is preferably a mixture of components (a l ) and (a 2 ), where (a 1 ) is also a mixture of brighteners in which R l is hydrogen and R 1 is sulfo means can be.
• the weight ratio (a l ) / (a 2 ) can vary widely and is particularly dependent on the binders used in the coating slip, essentially as described below.
• the symbol M preferably represents a colorless cation, primarily an alkali metal (in particular lithium, potassium or preferably sodium) or an ammonium cation which can be unsubstituted or substituted by lower alkyl or alkanol radicals, in particular by methyl, ethyl, ⁇ -hydroxyethyl and / or ß-hydroxypropyl; preferred cations M are potassium, sodium, unsubstituted ammonium and mono-, di- or triethanolammonium.
• alkali metal in particular lithium, potassium or preferably sodium
• ammonium cation which can be unsubstituted or substituted by lower alkyl or alkanol radicals, in particular by methyl, ethyl, ⁇ -hydroxyethyl and / or ß-hydroxypropyl
• preferred cations M are potassium, sodium, unsubstituted ammonium and mono-, di- or triethanolammonium.
• optical brighteners of the formula (I) used as component (a) can contain up to 12% by weight of salt from the preparation, but are preferably salt-free as far as possible (what is meant here are essentially the inorganic salts - especially alkali metal salts - and optionally Amine salts, which can occur as by-products in the manufacture and isolation of optical brighteners); the compounds of the formula (I), in which R 1 is hydrogen, precipitate out after production in an aqueous medium by salting out in the form of alkali metal salts and, after filtration and washing, are sufficiently pure to be used according to the invention; If amine salts are prepared, the compound can be acidified and the precipitated acid can, after filtering and optionally washing, be reacted with water, with the corresponding amine or with ammonia, which gives a very pure product.
• the compounds of formula (I), in which R 1 and R 2 each represent a sulfo group, are preferably dialyzed in the form of acid or alkali metal salt in aqueous solution, after which the acid can, if desired, be neutralized with an appropriate base; very pure products can be obtained in this way.
• Components (a) preferably contain no more than 5% by weight of inorganic salts from the preparation.
• the polyethylene glycol used as component (b) advantageously has an average molecular mass in the range from 1000-2500, preferably in the range from 1500-2500, in particular in the range from 1500-2200.
• the polyethylene glycols (b) can be used as commercial technical products.
• the molecular mass of such a polyethylene glycol generally varies within a relatively narrow range, in particular in the range from ⁇ 5% to ⁇ 10% of the relevant molecular mass, primarily from t5% for polyethylene glycol 1000 to ⁇ 10% for polyethylene glycol 3000.
• the weight ratio of component (b) to component (a) is advantageously in the range from 0.2: 1 to 5.0: 1; at least part of component (a) is preferably a component (a l ) and the weight ratio of component (b) to component (a l ) is advantageously in the range from 1.5: 1 to 5.0: 1; preferably 2.5: 1 to 5.0: .1; in particular 3.0: 1 to 4.0: 1. If component (a) is a mixture of (a l ) and (a 2 ), then is preferred the weight ratio of component (b) based only on component (a l ), while component (a 2 ) is not taken into account.
• the water content of the preparation is expediently at least that much that the preparation can still be stirred and is preferably easy to pour; in the case of concentrated preparations, the concentration of component (a) is advantageously 5-30, preferably 7-25,% by weight of the preparation, the water content is advantageously chosen so that the dry matter content of the preparation is in the range of 10-80%, preferably 25-60% by weight; if only (a l ) is used as component (a), then the dry substance content of the preparation is advantageously in the range of 35-60% by weight in the case of concentrated preparations.
• the aqueous preparations according to the invention preferably have a neutral to clearly alkaline pH, in particular in the range from pH 7 to pH 10; if necessary, this can be adjusted by adding bases, in particular bases corresponding to M (e.g. alkali metal hydroxides or carbonates, ammonia or amines).
• bases in particular bases corresponding to M (e.g. alkali metal hydroxides or carbonates, ammonia or amines).
• the brightener preparations according to the invention are very stable in storage and can be processed directly, i.e. diluted with water and / or metered directly into the coating slip preparations, and a further object of the invention is the use of the preparations according to the invention in paper coating slips for the production of lightening-containing paper coating slips or for the production of optically brightened, coated paper, in particular a process for the production of coated, at least brightened paper, which is characterized in that, after the sheet has been formed, a coating slip mixed with a preparation according to the invention is applied to the paper and fixed by thermal treatment .
• the coating slips are essentially aqueous preparations which contain at least one binder and, if appropriate, a white pigment, in particular a matting white pigment, and can additionally contain other customary additives (dispersants, iron ion binders, defoamers, etc.); the preparation according to the invention, which can optionally be prediluted, is added to these in the formulation.
• the binders can generally be any binders of the kind used in paper technology for the production of coating slips and can consist of a single binder (d 1 ) or also a mixture of (d 1 ) primary and (d 2 ) secondary binders.
• the sole or primary binder (d 1 ) is preferably a synthetic latex.
• the synthetic latices (synthetic resins) which are used in the coating slips as sole or primary binders are generally known and are described in numerous technical literature.
• polymers and copolymers of ethylenically unsaturated compounds primarily the following: butadiene styrene copolymers, which may additionally contain a carboxylated comonomer, polyacrylates, copolymers of alkyl acrylate and vinyl acetate, which may contain a comonomer containing carboxy groups, such as acrylic acid, itaconic acid or maleic acid and polyvinyl acetates containing a carboxy group-containing 5 comonomer.
• the secondary binders (d 2 ), which can optionally be used together with the primary binders (d l ), are generally known and are described in detail in the specialist literature, the most important representatives being the following: starch or casein (which, if appropriate can also be partially oxidized and / or hydrolyzed), modified cellulose such as carboxymethyl cellulose, and cellulose methyl ether, polyvinyl alcohol, low molecular weight, carboxyl group-containing polymers (in particular polycarboxylic acids, for example copolymers of acrylic acid C 1-4 alkyl ester and acrylic acid, which additionally contains as dispersing agent and as iron ions binder can serve), among them, in particular, the casein and the carboxy-containing polymers and polyvinyl alcohol are preferred.
• starch or casein which, if appropriate can also be partially oxidized and / or hydrolyzed
• modified cellulose such as carboxymethyl cellulose, and cellulose methyl ether
• polyvinyl alcohol low molecular weight
• substantially non-ionic emulsifiers in addition to the synthetic Lati e ces, in addition to the Polycarboxyitatien and / or in lieu of such conventional dispersants used for the latices to be dispersed in water, substantially non-ionic emulsifiers.
• the synthetic binders are already sold as dispersions, which may contain dispersants (eg from dispersion polymerization).
• Such white pigments are essentially matting white pigments and are generally inorganic or mineral substances, mainly calcium carbonate, calcium sulfate (satin white), aluminum silicates and aluminum hydroxides, aluminum magnesium silicates (chinaclay), titanium dioxide or barium sulfate (Blancfix) and also mixtures of such pigments.
• the white pigments and any other suitable additives are generally known in paper technology and are widely described in the specialist literature.
• Component (D) comprises the total binder content, ie the primary binder (d l ) and, if available, also the secondary binder (d 2 ), as well as the corresponding water contained in the latex (these latices are usually in water-containing form traded, mostly about 40-70%).
• Component (E) represents the additional water that is required for the desired coating slip.
• Component (F) is generally any white pigment, as is usually used in coating slips, in particular for matting the paper coating, and as described above.
• the relative weight ratios of components (D), (E) and (F) generally correspond to the usual coating slip compositions, and the coating slips may also contain other conventional additives, such as defoamers, buffer salts, bases, flow agents, etc. (see e.g. B.JJ Casey , "Pulp and Paper”;. Chemistry and Chemical Technology, 2nd Ed, Vol III, p 1646-1650).
• the optimal whiteness range can vary and can be determined for a given coating paste by a few preliminary tests; the optimum brightener concentration is generally advantageously in the range from 0.005 to 8.0, preferably — especially if component (a) component (a l ) is used without (a 2 ) - 0.05 to 4.0 parts by weight of the above-defined component (a), based on 100 parts by weight of white pigment (as a reference).
• the content of secondary binder (d 2 ) is advantageously chosen to be as low as possible, preferably no more than 1 part by weight (d 2 ) is then used per 100 parts by weight of white pigment.
• a preparation according to the invention is preferably used as component (X) which, as component (a), contains component (a l ) without (a 2 ) contains, as defined above and particularly preferred.
• a mixture of a synthetic latex (d l ) and a secondary binder or binder mixture (d 2 ) is used as the binder (D)
• one which the component (a l ) is mixed with is advantageously used as the preparation (X) component (a 2 ) as defined above; either the components (a 1 ) and (a 2 ) are both present in the preparation according to the invention, or the component (a 1 ) is added in the form of an inventive preparation and K o MPO component (a 2) is added as such or as an aqueous solution either with the inventive preparation containing the component (a l) prior to the metering into the coating composition, or is metered separately into the coating slip;
• Components (a l ) and (a 2 ) are preferably formulated together as a preparation according to the invention and the whole of the coating slip is metered in during the production thereof.
• component (D) is a mixture of a synthetic latex (d l ) and a secondary binder (d 2 ), then depending on the composition of the binder (D ) the optimal composition of the mixture (a l ) / (a 2 ) vary widely;
• the weight ratio (a l ) / (a 2 ) is, for example, in the range from 1: 0.05 to 1:20, primarily in the range from 1: 0.1 to 1:10;
• the weight ratio (a l ) / (a 2 ) is advantageously in the range from 1 / 0.5 to 1/10, in particular in the range from 1/1 to 1/5.
• the pH of the aqueous coating slips is preferably alkaline and can be adjusted with conventional bases (for example with alkali metal hydroxides or carbonates or preferably with ammonia) to values which are advantageously between 7.5 and 9, preferably between 8 and 8.5 .
• Suitable substrates for the coating slips are any type of paper, such as can usually be used for coating, from fine thin printing paper to cardboard and heavy cardboard, as are generally produced from a wide variety of cellulose fiber materials, e.g. Wood fibers, wood pulp, 1-year plant fibers, rags (linen, hemp, cotton, jute etc.) or refurbished waste paper.
• the paper to be coated can be unsized or sized. Occasionally, synthetic papers can also be used as a substrate.
• the new coating slips can be applied to the paper after sheet formation in a manner known per se using conventional coating devices (for example with a doctor blade, with brushes, with a knife or even with an air knife).
• the coating can be carried out batchwise or continuously, in particular also in the continuous production of paper at high speed.
• Fixing the brightener containing coating slip is carried out by heating, expediently as usual when drying (for example at 50-120 ° C., preferably 65-95 ° C.).
• the paper coated according to the invention can also be subjected to a special gloss aftertreatment.
• the coated papers obtained are ideal for good, clean and clear printing.
• the parts mean parts by weight and percentages by weight; the temperatures are given in degrees Celsius.
• the brightener numbering used in the examples corresponds to that in Table 1.
• table 3 lists further brightener preparations which are prepared as described in example 3, but using the optical brighteners (a 1 ) and (a 2 ) listed in table 3; in columns 4 and 5 the amounts of the respective optical brightener used are listed.
• the coating slips obtained in this way which have different proportions of brightener formulation, are then knife-coated onto the felt side of coating base paper in an application quantity of 20 g / m 2 using a roller knife and then dried with a warm air dryer at 90-95 ° C. for 1 minute.
• butadiene-styrene copolymer can also be used in the coating slip, e.g. 20% higher or lower, depending on the requirements placed on the physical properties of the coating. You also get a significant increase in whiteness compared to the blank.
• the brightener preparations (1) to (22) or (24) are used, which also enables high degrees of whiteness to be achieved.
• the papers coated with it have a high degree of lightening.
• the papers coated with this coating slip have a high degree of whiteness.
• the brightener preparations from Examples 3a to 3g are used instead of the brightener preparation from Example 3.
• Example C1 The procedure described in Example C1 is used, but that of Example 4 is used instead of the preparation of Example 2. A very good white effect is obtained. Instead of the preparation from Example 4, those from Examples 4a to 4k can be used.
• Example C2 The procedure is as described in Example C2, but instead of the preparation of Example 3, that of Example 4 is used. A very good white effect is obtained. Instead of the preparation from Example 4, those from Examples 4a to 4k can be used.

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• 1985
  • 1985-01-23 DE DE19853502038 patent/DE3502038A1/de not_active Withdrawn
• 1986
  • 1986-01-14 EP EP86810011A patent/EP0192600B1/fr not_active Expired
  • 1986-01-14 AT AT86810011T patent/ATE44785T1/de active
  • 1986-01-14 DE DE8686810011T patent/DE3664499D1/de not_active Expired
  • 1986-01-21 US US06/820,043 patent/US4717502A/en not_active Expired - Fee Related
  • 1986-01-22 JP JP61010288A patent/JPS61174269A/ja active Pending
  • 1986-01-23 ZA ZA86526A patent/ZA86526B/xx unknown

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