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
  • D21H19/00—Coated paper; Coating material
  • D21H19/02—Metal coatings
• • 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
  • D21H19/00—Coated paper; Coating material
  • D21H19/80—Paper comprising more than one coating
  • D21H19/82—Paper comprising more than one coating superposed
• • 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
  • D21H25/00—After-treatment of paper not provided for in groups D21H17/00 - D21H23/00
  • D21H25/08—Rearranging applied substances, e.g. metering, smoothing; Removing excess material
  • D21H25/12—Rearranging applied substances, e.g. metering, smoothing; Removing excess material with an essentially cylindrical body, e.g. roll or rod
  • D21H25/14—Rearranging applied substances, e.g. metering, smoothing; Removing excess material with an essentially cylindrical body, e.g. roll or rod the body being a casting drum, a heated roll or a calender

Definitions

• the present invention relates to a carton with a coating applied on one side by means of a cast coating process, a process for its production and its use.
• DE-B-1233248 describes a casting process in which a coating composition containing a metallic pigment and organic binder is applied to e.g. B. a paper web is applied and dried in contact with a heated high-gloss cylinder.
• a paper or cardboard is produced with a die-casting method Layer used.
• the layer consists of a synthetic resin binder not film-forming at normal temperature, the particles of which are melted between 71 ° C. and 99 ° C. to form a hard and glossy, continuous film during the casting process.
• the layer can also be applied to a base layer which, in addition to filler, contains one of the customary synthetic resin binders.
• a part of the synthetic resin binder to be used in the base layer can also be replaced by natural binders, so that 10 to 30% by weight of the total binder content of the base layer from e.g. B. starch, modified starch, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose and similar substances.
• the so-called “direct method”, as described above for DE-B-1233248, is specified and also the “indirect method”, in which the coating composition is applied to the high-gloss cylinder and the dry one before it is dried Paper is brought into contact with the still wet film, which is absorbed by the paper and pulled off the drum.
• the process known from DE-B-2310891 is not the casting process known from DE-A-1233248 (also called the direct method). Rather, with simultaneous formation of a continuous film from the polymer contained in the coating composition, one is initially used Part of the water evaporated and the film formed at a temperature above 100 ° C under a minimum pressure of 5 kp / cm2 against a high gloss cylinder. In order to prevent the film formed from sticking to the high-gloss cylinder during molding under pressure, up to less than 30% of an anti-sticking agent can be added to the coating composition. Among other things, z. B.
• sodium carboxymethyl cellulose, methyl cellulose, polyvinyl alcohol and polyvinyl pyrrolidone in amounts up to 10% based on the weight of the main polymer.
• the usual pre-coatings known from paper production, with and without pigment addition, are provided as the base layer.
• a metallized paper is known from EP-B-98368, in which the layer intended for metallization is shaped under similar process conditions as specified for DE-B-2310891.
• the coating composition contains 5 to 25 parts by weight of film-forming binder, based on 100 parts by weight of pigment, and thus has the pigment / binder ratio of the conventional paper coatings.
• This proposal is intended to eliminate the disadvantage which hitherto existed, which consisted in the fact that the coating surface intended for the metallization first had to be provided with a pre-coating based on organic solvents.
• the object of the present invention is now to provide a one-sided coated line cardboard using inexpensive coating raw materials, which due to its high gloss, smoothness and closeness should be used where a decorative impression is desired.
• the invention sees a special task in the formation of a line which is a direct metallization, i. H. Permitted without pre-painting with a varnish based on organic solvents, so that a product of the highest smoothness with high gloss and metallic appearance results.
• the invention also intends to provide a carton that can be printed by gravure printing in the non-metallized state and - at least with special printing inks - in offset printing. The printed product should have a good color balance and high print gloss.
• the present invention provides in a carton that has a coating applied on one side by means of a cast coating process, that the carton has a Cobb water absorption of 25 to 40 g / m 2 before application of the coating on the side provided for receiving the coating for 60 seconds and the line consists of a film-forming synthetic resin binder with a film-forming temperature ⁇ 40 ° C, a natural binder in an amount of 10 to 60% by weight, based on the total binder content, the rest: thickening agents and / or release agents and / or crosslinking agents in a total of not more than 10% by weight, based on the total binder content.
• cardboard means a flat structure, that is to say a cardboard web or a cardboard sheet.
• the carton is single-ply, in particular a carton is preferred, the pulp mass of which consists of 100% by weight of pulp fibers, based on the pulp mass.
• Another preferred embodiment provides for the admixture of up to 5% by weight of wood pulp fibers, based on the total fiber mass of a single-ply carton.
• a multi-layer cardboard can also be used, but it is necessary that the cardboard has a cover layer, the fibrous mass of which consists of 100% by weight of cellulose, or up to max . 5% by weight wood pulp fibers, rest: cellulose fibers are present.
• the top layer serves to apply the coat by means of the cast coating process.
• a cardboard is preferably used, the basis weight of which is between 150 and 350 g / m 2, calculated as fiber mass.
• a carton is used in which the required water absorption capacity of 25 to 40 g / m 2 was adjusted according to Cobb for 60 seconds by soaking the carton with a synthetic resin binder before application of the cast coating and after drying was treated with a soft or satin calender.
• Plastic dispersions based on butadiene-styrene, acrylic resin, methacrylic resin based, based on polyvinyl acetate or polyvinyl alcohol solutions and mixtures thereof are particularly suitable as synthetic resin binders.
• polyacrylamide has also proven to be very suitable.
• the amount of synthetic resin binder to be applied is at least 1 g / m2 and max. 10 g / m2.
• the amount applied is preferably 1 to 3 g / m2, in particular 1 to 2 g / m2.
• a coating of one or more superimposed layers can also be applied to the side provided for receiving the cast coating, which coating consists of a film-forming synthetic resin binder and / or natural binder composition, and the coating formed to form the desired surface properties is satined.
• This coating can be produced with the usual coating devices of the paper and cardboard industry; in addition, the coating still contain mineral pigment or dyes.
• the thickness of the cardboard should be in the range from 145 to 400 »m, preferably the thickness is not greater than 370» m.
• mineral pigment can also be contained in the cardboard, preferably in the range from 9 to 13% by weight, expressed as ash content, based on the total mass per unit area of the cardboard.
• the proportion of the natural binder in the coat applied on one side by means of a cast coating process is 20 to 35% by weight, based on the total binder content.
• the smoothness of the side of the cardboard intended to receive the cast line should be at least 50 Bekk-sec. lie, preferably the Bekk smoothness is> 150 sec.
• the amount of the coating applied by means of the casting process is at least 5 g / m 2, but preferably more than 10 to max. 15 g / m2.
• the application of lower coat weights - calculated as dry weight fractions - can lead to the result that the surface of the carton produced does not have the closed structure and the desired high gloss, which according to a preferred embodiment is 88 to 98% - measured at an angle of 75 Degrees (according to Lehmann) - lies.
• the coating applied by means of a casting process consists at least of 90% by weight only of binder and, moreover, only contains the usual auxiliaries which are used in the coating process, that is to say e.g. B. release agents such. B. calcium stearate, crosslinking aid or one of the usual thickening aids on a natural or synthetic basis.
• B. release agents such. B. calcium stearate, crosslinking aid or one of the usual thickening aids on a natural or synthetic basis.
• the invention also encompasses a method of making a high gloss, glossy cardboard coated on one side.
• a raw cardboard is impregnated with an impregnating liquid containing or consisting of a synthetic resin binder, dried and satinized with a super or soft calender.
• a composition is applied to the satin surface, which consists of a film-forming synthetic resin binder, a natural binder in an amount of 20 to 60% by weight, based on the total binder content, the rest: thickening agents and / or releasing agents and / or crosslinking agents in an amount of in total not more than 10% by weight, based on the total binder content, and the applied coat is leveled and with a heated high-gloss cylinder with simultaneous drying Formation of a high-gloss surface contacted.
• the raw cardboard instead of impregnating the raw cardboard with a synthetic resin binder, the raw cardboard is coated by coating it with one or more layers with a composition containing or consisting of a film-forming binder and / or natural binder, and the coating formed is dried and satinized.
• a cast line is then applied in the manner described above. After each of the two processes, a cast line is formed, which can be called a less porous, closed film layer.
• the film-forming synthetic resin binders to be used to form the cast coating come in the form of aqueous dispersions, preferably based on the polymers and copolymers of acrylic acid esters, methacrylic acid esters, butadiene-styrene, vinyl acetate and vinylidene chloride.
• the synthetic resin binders preferably have film-forming temperatures of ⁇ 30 ° C.
• the raw cardboard is impregnated with synthetic resin binder, this is preferably already done in the paper machine, e.g. B. in a size press.
• the cardboard web is coated with a synthetic resin binder on the side of the cardboard intended to hold the cast coating instead of an impregnation, the same film-forming synthetic resin binders as for the cast coating are preferably used for this, however, synthetic resin binders with a higher film-forming temperature may also be used here .
• Cellulose derivatives such as carboxymethyl cellulose, hydroxyethyl cellulose, preferably casein and starch, modified starch and mixtures of the above-mentioned natural binders serve as natural binders for producing the coating and the cast coating.
• the proportion of the natural binder in the coating is preferably not more than 70% by weight, very particularly preferably in a range between 10 and 50% by weight, in each case calculated as dry weight proportions based on the total binder content.
• Chalk, kaolin and titanium dioxide can be used as the mineral pigment in the coating, the total binder content being calculated as Dry weight fractions, based on the pigment fraction, is 10 to 20% by weight.
• the carton according to the invention can be produced particularly inexpensively.
• a disadvantage arises in that only coating compositions with a low solids content can be produced and the economics are questioned by the high drying effort required.
• the coating has a Bekk smoothness in the range from 200 to 2,000 seconds.
• a coating with a mass per unit area of at least 5 g / m 2 has proven to be necessary to achieve such a smoothness value.
• the smoothness of the cast coating is so high that it cannot be measured with the usual Bekk method.
• the cardboard according to the invention is suitable for direct metallization without pre-coating the cast coating on the basis of organic solvents.
• the carton according to the invention is the use as a print carrier for the gravure printing process.
• the gravure printing ink has a very good color level and a print image with high printing gloss is created.
• a single-layer cardboard the pulp of which consists of 100% by weight of cellulose fibers and has a mass per unit area of 180 g / m2, is impregnated with polyacrylamide as a synthetic resin binder, with 2 g / m2 - calculated as dry weight fractions - being absorbed. After the cardboard web has dried, it is calendered. A measurement of the water absorption capacity according to Cobb gives a result of 26 g / m2 reduced value during 60 seconds. A Bekk smoothness of 120 seconds is measured.
• composition is applied to the cardboard prepared in this way: starch soluble in cold water 29 parts by weight synthetic binder based on polyacrylate resin 68 parts by weight Calcium stearate 3 parts by weight
• This example describes the use of a multi-layer cardboard with a waste paper-containing insert and a cover layer, the fiber mass of which consists of 100% by weight of cellulose.
• the ceiling has one Basis weight of 25 g / m2, while the total basis weight of the raw cardboard is 210 g / m2.
• Example 1 With the recipe for the production of the cast coating given in Example 1, a cast coating is formed on the calendered coating in accordance with the procedure given in Example 1, an application weight of 7 g / m 2 - calculated as dry weight fractions - being achieved. The result obtained corresponds to that of Example 1 with regard to the gloss produced and the surface being closed.
• the cardboard is excellently metallizable.
• the binder composition for the coating corresponds to that given in Example 2.
• the result obtained shows a good covering of the waste paper insert of the cardboard, so that an excellent printable cardboard is produced.

Landscapes

• Paper (AREA)
• Diaphragms For Electromechanical Transducers (AREA)
• Portable Nailing Machines And Staplers (AREA)
• Orthopedics, Nursing, And Contraception (AREA)
• Machines For Manufacturing Corrugated Board In Mechanical Paper-Making Processes (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=6445915

Family Applications (1)

Country Status (9)

Families Citing this family (4)

Family Cites Families (3)

• 1991
  • 1991-11-29 DE DE4139386A patent/DE4139386C1/de not_active Expired - Fee Related
• 1992
  • 1992-10-30 DE DE59202829T patent/DE59202829D1/de not_active Expired - Fee Related
  • 1992-10-30 DK DK92923153.8T patent/DK0614502T3/da active
  • 1992-10-30 AT AT92923153T patent/ATE124741T1/de not_active IP Right Cessation
  • 1992-10-30 JP JP5509750A patent/JPH07501362A/ja active Pending
  • 1992-10-30 EP EP92923153A patent/EP0614502B1/de not_active Expired - Lifetime
  • 1992-10-30 WO PCT/EP1992/002488 patent/WO1993011299A1/de active IP Right Grant
  • 1992-10-30 ES ES92923153T patent/ES2074368T3/es not_active Expired - Lifetime
  • 1992-10-30 CA CA002124576A patent/CA2124576A1/en not_active Abandoned
• 1994
  • 1994-05-25 FI FI942441A patent/FI942441A/fi not_active Application Discontinuation

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