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
  • D21H19/36—Coatings with pigments
  • D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
  • D21H19/54—Starch
• • 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
  • D21H19/36—Coatings with pigments
  • D21H19/44—Coatings with pigments characterised by the other ingredients, e.g. the binder or dispersing agent
  • D21H19/56—Macromolecular organic compounds or oligomers thereof obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H19/58—Polymers or oligomers of diolefins, aromatic vinyl monomers or unsaturated acids or derivatives thereof

Definitions

• the invention relates to a heat-sealable paper, the backing paper of which is provided on one of its main surfaces with a heat-sealable coating and the use of this paper for lamination with other material surfaces.
• heat-sealable papers are known. These materials have, on a main surface of the backing paper, a polymeric binder which, at temperatures above 80 ° C., softens and develops adhesive strength and optionally contains pigments, so that these papers can be bonded to other material surfaces using heat and pressure.
• the disadvantage of such heat-sealable coatings is their tendency to block, ie undesirable premature adhesion with other layers, especially if the papers are rolled up after the heat-sealable layer has been applied and dried. In this case, adhesion of the coated main surface to the uncoated main surface occurs, so that re-unrolling and further processing of the heat-sealable papers, in particular after storage, is difficult or prevented.
• the object of the invention is to reduce the tendency of the heat-sealable layer to block without the heat-sealability being impaired thereby.
• a heat-sealable paper with a backing paper and a pigmented heat-sealable layer applied to one of the main surfaces of the backing paper which is characterized in that the heat-sealable layer contains 8 to 25% by weight, based on the dry substance of the heat-sealable layer, contains calibrated starch grains with an average grain size over 15 ⁇ m.
• the content of non-gelatinized starch granules is preferably 12 to 15% by weight, based on the dry substance of the heat-sealable layer.
• the tendency of the heat seal layer to block can be reduced by changing the composition and using particulate materials that do not soften at sealing temperatures.
• such additives generally also change the behavior in heat seals, for example higher temperatures or pressures are required in order to achieve the desired adhesion of the heat seal layer to surfaces to be connected to it.
• the blocking tendency of heat seal layers can be reduced or eliminated without impairing or changing the behavior during heat sealing if the heat sealable layer contains unglazed starch granules, the size of which is selected such that they extend to and beyond the surface of the heat sealable layer .
• the average grain size of the calibrated, non-gelatinized starch granules is preferably more than 20 ⁇ m.
• a grain size distribution of 98% by weight> 10 ⁇ m, 55% by weight> 20 ⁇ m, 82% by weight> 16 to 32 ⁇ m has proven to be particularly favorable.
• Maize, potato, cereal (such as wheat, rye, etc.), rice, tapioca or arrowroot starch (arrowroot starch) can be used as the non-gelatinized coarse-grained starch.
• the starch particles can be classified by various known methods, for example air classification, sieving methods, wet methods or cyclones.
• the starch In order to increase the gelatinization temperature of the starch granules, the starch can be chemically modified or cross-linked.
• the heat seal layer can contain the known heat sealable, film-forming polymers.
• Suitable heat-sealable polymers are, for example, polyvinyl acetate, polyvinyl chloride, copolymers of styrene and acrylic esters.
• the heat-sealable coating is applied to the backing paper from aqueous dispersion by conventional means and then dried under conditions under which the non-gelatinized starch granules contained in the heat-sealable coating composition do not gelatinize, so that the particle structure of the starch granules is retained in the dried layer.
• the heat-sealable layer is applied to the backing paper in an amount of 12 to 24 g / m2, preferably 15 to 20 g / m2.
• the layer thickness of the heat-sealable layer is preferably 10 to 20 ⁇ m, very particularly preferably 15 to 18 ⁇ m.
• the heat-sealable paper according to the invention can be used for lamination with other material surfaces, such as paper, cardboard, textiles and plastic films in the form of sheets or sheets.
• the heat-sealable layer to be bonded to one another and the further material surface are brought into full-area contact with one another using heat and pressure, and the layers are adhesively bonded to one another.
• the heat-sealable paper according to the invention can be sealed in a heat-sealing calender with paper or cardboard to form a composite material.
• the backing paper used can be subjected to a satin coating before the heat-sealable coating is applied.
• Suitable correspondingly sized backing papers can be produced from conventional cellulose mixtures with basis weights of 80 g / m2 to 300 g / m2, preferably 140 g / m2 to 200 g / m2.
• heat-sealable paper according to the invention it is also possible to divide the heat-sealable paper according to the invention into sheets and to connect sheet-like or otherwise divided heat-sealable paper to other desired material surfaces by heat sealing.
• heat-sealable sheets with paper or cardboard sheets of the appropriate size can be laminated into a composite material.
• the heat-sealable paper according to the invention also shows under unfavorable conditions, e.g. high room temperatures up to 45 ° C and the usual pressure loads in paper rolls or paper stacks no undesirable blocking and can therefore be processed without problems even after storage. Changes to the sealing conditions are not necessary for later heat sealing.
• a paper with a mass per unit area of 140 ⁇ 5 g / m2 is produced on a Fourdrinier paper machine.
• the paper stock composition consists of 62.5% by weight long fiber sulfite pulp, 25% by weight short fiber sulfate pulp and 12.5% by weight linters.
• the paper is sized in the usual way with 1.0% by weight of resin soap and 3 to 4% by weight of alum.
• the pulp contains further additives such as 6% by weight TiO2, 1.9% by weight Na stearate, 6% by weight carboxymethyl cellulose and optical brighteners to increase the whiteness.
• the percentages of the other additives relate to the fiber content.
• the paper thus produced is then satinized in a super calender, so that a Bekk smoothness of 100 to 200 sec. results.
• a paper with a mass per unit area of 140 ⁇ 5 g / m2 is produced on a Fourdrinier paper machine.
• the paper stock composition consists of 62.5% by weight long fiber sulfite pulp 25% by weight, short fiber sulfate pulp and 12.5% by weight linters.
• the paper is sized in the usual way with 1.0% by weight of resin soap and 3 to 4% by weight of alum.
• the pulp contains further additives such as 6% by weight Ti02, 1.9% by weight Na stearate, 6% by weight carboxymethyl cellulose and optical brighteners to increase the whiteness.
• the percentages of the other additives relate to the fiber content.
• the paper thus produced is then satin-finished in a super calender, so that a Bekk smoothness of 100 to 200 seconds results.
• This paper was coated on one side with the following coating composition on a test coating machine with a blade coater as the coating unit:
• the backing paper is produced in the same way as in Example 1.
• the following coating composition was applied on a coating machine, equipped with an air brush as a coating head, in comparison to the standard coating without starch granules:
• the block test was carried out in the same way as in Example 1, and the paper according to the invention also showed no appreciable sticking of the individual paper layers.
• the paper rolls were stored for 8 weeks. Even after this long storage period, there was no picking / sticking when rolling on a cross cutter.
• the paper cut to size 75 x 105 cm was then stored again in a stack height of approx. 150 cm, resulting in a total weight of approx. 750 kg, 8 weeks before it was subjected to single sheet sorting and as a finished product in pack sizes from a paper giant (1,000 sheets) was packed.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Paper (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6453763

Family Applications (1)

Country Status (2)

Cited By (2)

Citations (1)

Family Cites Families (1)

• 1992
  • 1992-03-11 DE DE19924207690 patent/DE4207690C1/de not_active Expired - Fee Related
• 1993
  • 1993-03-02 EP EP93103271A patent/EP0560174A1/fr not_active Withdrawn

Patent Citations (1)

Also Published As

Similar Documents

Legal Events