FI76827B - TRYCKFAERG, TRYCKFOERFARANDE OCH TRYCKT PRODUKT. - Google Patents

Description

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Printing ink, Printing method and printed product

The invention relates to an ink comprising a solution of a water-soluble salt formed between an acid and an alkaloid, a printing method in which the ink is printed on a substrate, preferably by gravure or screen printing, and a printed product, preferably a cigarette wrapper, comprising a substrate, preferably paper, between an alkaloid and an acid. the printed precipitate-10 nuclei of the water-soluble salt formed.

Alkaloids have a variety of uses, but they tend to have the disadvantage of difficult to achieve prolonged and controlled availability. They are bases, so they can form salts with simple acids, but they are generally very soluble and easily leave surfaces. Salts with crosslinked cation exchange resins are known, but they are insoluble and thus mainly inactive and difficult to apply. For example, nicotine (which is useful as an insecticide for insects) is highly volatile and its salts with simple acids are highly soluble.

GB 1 391 614 proposes the formation of nicotine pectinate or nicotine alginate and its incorporation into tobacco products. Typically, a slurry is formed from the tobacco screening waste and / or wreck and the nicotine pectinate or alginate is added to the slurry, either as a powder or solution, and the slurry is cast into a sheet. The values mentioned in the patent for the nicotine content of the salts are between 20 and 31.5%. The values mentioned in 30 for the salt concentration in solution are about 1 or 2%.

U.S. Patent No. 4,236,532 discloses tobacco rods in which the wrapper is film-printed with ink dots containing a nicotine salt, usually 35 nicotine hydrogen tartrate. The salt is first prepared as a printing ink with rheological properties suitable for film printing by combining silica and carboxymethylcellulose with a solution of nicotine hydrogen tartrate. .

The presence of volatile acid components is particularly undesirable in tobacco products.

Despite the undesirability of these factors, it has previously been accepted that they are unavoidable and that successful printing of alkalis makes it necessary to incorporate conventional printing additives and provide the alkaloid with a volatile acid salt. The present invention is based in part on the realization that these considerations can be avoided.

The ink according to the invention, which contains a solution of a water-soluble salt formed between an acid and an alkaloid, is characterized in that the salt acts as a binder and viscosity regulator and that the acid is a polymeric acid which is a polysaccharide and the alkaloid is selected from nicotine, anabasine and nornicotine.

The ink preferably consists essentially only of solvent and salt, so that the ink is preferably free of other viscosity control agents, binders or additional components used to control the rheology or other printing properties of the ink. However, if desired, one or more such components may be present, but it is generally unnecessary to include organic thickeners in the ink because the salt formed by the alkaloid and the polymeric acid is capable of imparting the necessary organic thickening properties. If an inorganic substance is required to regulate the rheology, then this may be present. Suitable inorganic materials include silica, titanium dioxide or the like. The ink may contain additives necessary to modify the properties of the final printed substrate. For example, if the printed substrate is used as a wrapper for a tobacco can, the ink may contain burning additives such as spices,

II

3 76827 musters or combustion modifiers and may contain dyes.

The viscosity and other flow properties of the ink can be selected by properly selecting the solids content of the ink, the molecular weight of the polymer salt used to form the salt, and the molecular weight of the polymeric acid used to form the salt. The viscosity is generally selected to be 10-500 poise, with the exact value selected according to the printing method. For example, the gravure viscosity is preferably 10 to 200, most preferably 50 to 150 poise, while the film printing viscosity is preferably 100 to 450, most preferably 150 to 400 poise.

The ink solvent must be one in which the salt is soluble, i.e., in which the salt forms a true or colloidal solution. Generally, the solvent is a polar solvent. It may be an organic polar solvent, for example an alcohol, but water or a mixture of water and an organic polar solvent is preferred.

The alkaloid may be nicotine, anabasine or norni-20 cotin. Alkaloids are compounds that may occur in nature or may be analogous to them or derivatives thereof that need to be synthesized. Nicotine is the most preferred alkaloid.

The ink is preferably substantially free of any alkaloid that is not present as a salt with the polymeric acid.

A polymeric acid is a polymer that contains a repeating moiety that contains at least one acid group. In the present invention, the polymeric acid is preferably a polysaccharide capable of forming a water-soluble salt having the desired alkaloid content. When a salt is said to be water-soluble, it is meant that it forms a true solution or a colloidal solution in water or an aqueous organic solvent.

The acidic groups of a polymeric acid are generally carboxyl groups, but other salt-forming acid groups that may be present include phosphate, borate, sulfate, and sulfonate.

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The polymeric acid may be naturally occurring or synthetic. If it occurs naturally, it is generally modified to increase the content of its acidic groups to thus allow the added alkaloid content in the salt. The salt usually contains at least 20% and often at least 30% by weight of alkaloid, but by increasing the content of acid groups the amount of alkaloid in the salt can be increased to at least 40% and even up to 60% or more.

Preferably, the polymeric acid is a polysaccharide modified by adding its acidic content. The average number of acid groups per saccharide unit is generally increased by at least 0.1 and preferably by at least 1. A preferred way to increase the acid content of a polysaccharide is carboxyalkylation. The alkyl group of the carboxyalkyl generally contains 1 to 6, preferably 1 to 4 carbon atoms, e.g. methyl or butyl. Another way to increase the acidity of a polysaccharide is to react it with a polyhydric acid (or a salt thereof, followed by acidification if necessary). Suitable polyhydric acids include phosphoric, boric, sulfuric, tartaric and malonic acids. The polyhydric acid is usually dibasic or tribasic.

The polysaccharide may consist of 5-membered rings, but is preferably composed of 6-membered rings. Suitable polysaccharides include alginic acid and pectic acid. The salts of these disclosed in GB Patent 1,391,614 may be useful in some printing methods, but tend to be quite unsatisfactory because the salts of alginic acid and pectic acid 30 tend to have a high molecular weight and therefore tend to form very low viscosities. Thus, when using such salts, it is generally possible to obtain only very small increases in nicotine content. More satisfactory results can be obtained if the alginic acid, pectic acid or other polysaccharide is modified to increase its acid content, usually by carboxyalkylation or by reacting it with a polybasic acid to increase the degree of acid substitution by at least 0.1 per unit number of acid substitutes (i.e. 5 by at least 0.1). In general, the replacement rate increases by (0.1 or 1) -2. Suitable polysaccharides thus comprise borated, carboxymethylated, carboxybutylated or phosphatized alginic or pectic acid with increased acid substitution rates by 0.1-2.

IQ The preferred polysaccharide is cellulose, in part due to the easy availability of relatively low molecular weight celluloses. Again, it is desirable to modify it with an acid substitution of at least 0.1 and preferably (0.8 or 1) -3. Each hydroxyl group in cellulose or other polysaccharide remaining after acid substitution is present as free hydroxy groups or is present as ether groups formed with, for example, C 1-6 alkyl or hydroxyalkyl groups such as methyl, ethyl, hydroxyethyl and hydroxypropyl.

20 ° Preferred cellulose compounds are carboxymethylated and carboxybutylated cellulose and cellulose phosphate, each of which has an acid substitution degree of at least (0.8 or 1) up to 3, and the corresponding compounds in which the hydroxy groups in the ring have been converted to ethers of methyl, ethyl , hydroxyethyl or hydroxypropyl groups.

The polysaccharide contains at least three units and normally more, for example at least 40 and often at least 100 units. In general, it is desirable that it does not retain more than 10,000 units of si-30 and normally contains significantly less than this, typically less than 5,000 units, because higher molecular weights result in products that form very viscous solutions that can be difficult to handle. . Preferably, the polysaccharide contains less than 1000 units and the best results are often obtained with polysaccharides containing 50-300 units.

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Preferred synthetic polymers that can be used as the polymeric acids in the invention are polymers of acrylic, methacrylic and maleic acids. The polymers preferably contain 500 to 4,000 repeating units and thus may have molecular weights of, for example, 10,000 to 1 million, but again lower molecular weights, typically 10,000 to 100,000, are often preferred. Other polymeric acids may be used for some purposes, for example, polymers of butadiene carboxylic acid 10 and straight-chain styrenesulfonic acid. Although high molecular weight synthetic polymers (e.g., polyacrylic acid, molecular weight greater than 100,000) can provide useful results, the best printing combinations are generally formed using polysaccharide acids.

Polymeric acids are known substances or can be prepared by methods consistent with well known methods. Alkaloid salts of polymeric acids can be prepared by combining the alkaloid with a polymeric acid dissolved in a polar solvent. If the polymeric acid is initially obtained in the form of an alkali metal salt (e.g. sodium carboxymethylcellulose), it is preferably converted to its free acid form before mixing with the alkaloid. This conversion can be carried out in a known manner by treatment with a mineral acid, but it has been found that the best results and the highest conversion and thus the highest possible alkaloid content are obtained if the conversion is carried out by ion exchange with a cation exchange resin.

A common way to isolate an amine salt is to crystallize or precipitate it from the solution in which it is formed and separate the precipitate by filtration. For example, after the addition of nicotine to an aqueous solution of a polyacrylic acid or other synthetic polymer, a precipitate of a polyacrylic alkaloid salt is formed on standing, which can be separated by filtration.

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The salt can also be formed in the same way when polysaccharic acid is used instead of polyacrylic acid, but the yield of the salt, and in particular the nicotine content of the salt, tends to be rather low. Surprisingly, it has been found that improved results can be obtained if a polysaccharide-alkaloid solution is formed by combining a polysaccharide and an alkaloid in a polar solvent and this solution is then evaporated. Evaporation can be completed to give a solid, or the solid can be separated from the concentrated solution by crystallization or precipitation, and the solid can then be redissolved in the selected polar solvent to form an ink. Preferably, however, the ink is prepared merely by evaporating the solution 15 to the desired concentration and desired physical properties.

Evaporation can take place by conventional methods, e.g. by distillation (preferably under reduced pressure) or by spray drying.

The salt content of the ink is generally at least 10% or 20% by weight and most preferably 30-40% by weight and can be up to 50%. The content of nicotine or other alkaloid present as a salt with the polymeric acid is generally at least 10% by weight of the ink, normally at least 17% and preferably 20-25% or more.

The sheet substrate printed in accordance with the invention is generally paper, but any substrate may be used, provided that it is suitable for the intended end use of the printed product. The printing can take place by conventional printing methods, such as film or gravure printing.

Preferably, the ink is printed as a dot pattern. The printed dots or other layers are preferably elevated on the substrate and are typically 50-100 microns high and 0.2-1.0 mm in diameter or other maximum size.

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The printed substrate can be used as a source from which an alkaloid with known properties can be released in a controlled manner at a selected location. If an alkaloid (e.g., anabazine or nicotine) is an insecticide, the substrate is toxic to insects.

Preferably, however, the alkaloid is nicotine and the printed substrate forms part of the tobacco rod, and even more preferably it is used as a tobacco rod wrapper. Thus, the advantages described in U.S. Patent No. 4,236,532 can be achieved without suffering the disadvantages of incorporating tartaric acid or excess carboxymethylcellulose.

The following examples illustrate the invention.

Example 1 30 g of sodium carboxymethylcellulose with a degree of substitution of 1.2 and an average degree of polymerization of about 1100 were geled in 300 ml of water. 50 g of a cation exchange resin sold under the trade name Duolite 225 in acid form was stirred in the solution and the mixture was allowed to stand for 20 hours. The resulting gel was filtered through a muslin cloth to remove the ion exchange resin and was a solution of the acid form of carboxymethylcellulose.

30 g of nicotine was added to the filtrate, and the mixture was mixed well. Water was removed from the solution by distillation under reduced pressure using a rotary evaporator. Evaporation was continued until the solution was sufficiently concentrated to a consistency suitable for printing. At this point, its solids content was about 33% by weight and analysis showed that its nicotine content was about 17% by weight.

Its viscosity was 130 poise.

The solution was then gravure printed on one surface of a conventional cigarette paper and the dots were dried by exposure to air at 100 ° C for 1 minute. The dried-35 points had a diameter of about 1 mm and a height of about 75 p., And the distance between their centers ti 9 76327 was essentially flat and was about 2 mm. The dry weight of the printed material was about 3 mg / cm and the analysis showed that the dots consisted of the Nicotine salt of carboxymethylcellulose containing 47% by weight of nicotine. Nicotine-5 could not be removed by washing with hexane or diethyl ether.

In another process, the solution was concentrated to a dry matter content of about 20% and printed on a conventional paper surface using an intaglio printing machine. The printed product was dried by exposure to air at 100 ° C for 1 minute. The dried printed dots had a diameter of about 1 mm and a height of about 40 microns, with a distance between the centers of the printed dots of about 2 mm. The weight of the printed material was about 1.9 mg / cm 2 and the nicotine content of the dots was about 44% by weight.

Example 2 288 g of carboxybutylcellulose having a degree of substitution of 1.2 and a degree of polymerization of less than 1100 were slurried in 2500 ml of water, 200 g of nicotine as the free base were added to the slurry, and stirring was continued until a homogeneous gel formed. The gel was suitable for use as a printing combination. The printed precipitates contained 40% by weight of free base nicotine.

Example 3 50 g of carboxymethylhydroxypropylcellulose prepared by carboxymethylation of hydroxypropylcellulose having a degree of polymerization of less than 500 was dispersed in 500 ml of water. To the stirred dispersion was added 36 g of nicotine free base to give a homogeneous gel suitable for use as a printing combination. The printed precipitates contained 40% nicotine.

Example 4 50 g of cellulose phosphate having a degree of substitution of 35 0.9 and a degree of polymerization of less than 1,000 were dispersed in 500 ml of water. To the stirred dispersion was added 10 76827 38 g of nicotine as the free base and stirring was continued until a homogeneous gel formed. The gel was suitable for use as a printing combination. The printed precipitates contained 43% by weight of nicotine.

Example 5 195 g of a phosphate ester of alginic acid with a degree of substitution of 0.9 and a degree of polymerization of 1000 were slurried in 1950 ml of water. To the rapidly stirred slurry was added 215 g of nicotine as the free base; 10 a homogeneous gel was formed which was suitable for use as a printing combination. The printed precipitates contained 53% nicotine.

Example 6 175 g of alginic acid (Alginate Industries, LDB grade) was slurried in 1450 ml of water and 180 g of nicotine as the free base was added to the slurry. To the gelled solution was added 31 g of ortho-boric acid dissolved in 600 ml of water, which caused the viscosity of the gel to increase significantly. The gelled product was suitable for use as a printing combination. The printed precipitates contained 50% by weight of nicotine.

Example 7 76 g of alginic acid were slurried in a solvent mixture of 480 ml of methanol and 120 ml of water. 112 g of nicotine-25 as the free base was added to the slurry, which was stirred at high speed until a homogeneous gel having a viscosity of 150-400 poise was formed; the gel was printed on a roll film press and the print was dried by exposure to air at 90 ° C for 1 to 30 minutes. The dried printed dots had a diameter of about 1 mm and a height of about 60 microns. The nicotine content of the printed dots was about 38% by weight.

Example 8

The ink combination described in Example 7 was diluted with methanol / water (4: 1) to give a printing compound 76827 / having a viscosity of 150 po at 20 ° C. The combination was applied to conventional cigarette paper by gravure printing and the print was dried by exposure to air at 85 ° C for 1 minute.

5 The printed dots were about 1 mm in diameter and about 45 microns high. The nicotine content of the printed dots was about 38% by weight.

Example 9 19.5 g of a phosphate ester of alginic acid having a degree of substitution of 0.9 and a degree of polymerization of 1000 were slurried in 200 ml of water. 21.5 g of anabasine, 1-2 (3-pyridyl) -piperidine were added and the mixture was stirred well. A homogeneous gel was formed which was suitable for use as a printing combination. The printed precipitates contained 51% ana-15 basin.

Example 10 19.5 g of a phosphate ester of alginic acid having a degree of substitution of 0.9 and a degree of polymerization of 1000 were slurried in 200 ml of water. 19.5 g of nornicotine, 1-3 (2-20 pyrrolidyl) pyridine were added and the mixture was stirred well. A homogeneous gel was formed which was suitable for use in the printing combination. The printed precipitates contained 48% nornicotine.

Example 11 73 g of polyacrylic acid having a degree of polymerization of 3000 were dispersed in 1 liter of water, and 7 g of nicotine as the free base were added to the stirred mixture. Evaporation of the solvent under reduced pressure gave a brittle hygroscopic solid containing 50% by weight of nicotine. Nicotine could not be removed by repeated washing with hexane. The solution could be used for printing after partial evaporation.

Claims (10)

12 7 682 7 A printing ink comprising a solution of a water-soluble salt formed between an acid and an alkaloid, characterized in that the salt acts as a binder and a viscosity regulator and in that the acid is a polymeric acid which is a polysaccharide and the alkaloid is selected from nicotine, anabasine and nornicotine . The ink according to claim 1, characterized in that the alkaloid, binder and viscosity regulating components of the ink consist essentially only of an aqueous solution of salt and the ink optionally contains one or more additives selected from dyes, spices, smoke generators and combustion modifiers. . Ink according to Claim 1, characterized in that the alkaloid is nicotine. Ink according to one of the preceding claims 20, characterized in that the polymeric acid is a polysaccharide selected from alginic acid, pectic acid and cellulose, and that the polysaccharide is preferably modified to increase its acid content by carboxyalkylation or reaction with a polybasic acid. . Printing ink according to one of the preceding claims, characterized in that the amount of alkaloid is at least 40% by weight of the polymeric acid and alkaloid. Ink according to Claim 1, characterized in that the amount of salt in the solution is at least 20% by weight. The ink according to claim 1, characterized in that it has a viscosity of 10 to 35,500 poise. Il 13 7632 7 Printing method in which the printing ink is printed on a substrate, preferably by gravure or screen printing, characterized in that the printing ink is an printing ink according to any one of claims 1 to 7. 9. A printed product, preferably a cigarette wrapper, comprising a substrate, preferably paper, with printed precipitates of a water-soluble salt formed between an alkaloid and an acid, characterized in that the acid is a polymeric acid which is a polysaccharide and the alkaloid is selected from nicotine, anabasine and nornicotin . A product according to claim 9, characterized in that the alkaloid is substantially completely present as a salt with a polymeric acid which is a polysaccharide and the alkaloid is nicotine. 14 76327