EP0895553B1 - Process for surface treatment of material webs, in particular paper and cardboard webs, using anti-adhesive agents - Google Patents

Abstract

PCT No. PCT/EP97/01953 Sec. 371 Date Nov. 5, 1998 Sec. 102(e) Date Nov. 5, 1998 PCT Filed Apr. 18, 1997 PCT Pub. No. WO97/41300 PCT Pub. Date Nov. 6, 1997The invention relates to a process for the thermomechanical surface treatment of flat webs of material, particularly those made of paper and carton, and to agents for performing said process. According to the process of the invention, adhesion between the flat web of material and the surface of the tool used in thermomechanical surface treatment, e.g., a roll or a press, is reduced or prevented by using an abhesive agent, which contains dicarboxylic dialkyl esters and/or diisoalkyl esters of C2-C12 dicarboxylic acids with C1-C13 n- and/or iso-alkanols as component with abhesive effect. The abhesive agent is preferably employed as an oil-in-water emulsion and is either applied to the surface of the tool used in said thermomechanical treatment or is added to the impregnating fluid or the paper coating mass or the moistening water or the steam in pre-moistening, or is applied to the paper web after the impregnating unit or directly before the smoothing roll. A steam-volatile abhesive agent is preferably used which then is metered through the steam line for steam moistening.

Description

The invention relates to the improvement of the thermal-mechanical surface treatment of sheet-like material webs, in particular paper and cardboard webs, through the Use of means that improve the adhesion between the sheet-like material web and the surface of the used for thermal-mechanical surface treatment Tool, e.g. B. a roller, reduce or even avoid (so-called abhesive).

The methods for thermal-mechanical surface treatment represent the manufacturing process special paper and cardboard qualities represent the last process stage in which the Properties of the material web changed significantly and adapted to the requirements of use can be. The requirement profile for types of paper and cardboard is varied and includes properties such as permeability, color absorption, printability or special barrier properties, e.g. B. compared to solvent-based or aqueous coatings, which in turn are characterized by such paper properties as micro and Macro roughness, porosity, absorbency, resistance to picking and abrasion, freedom from dust influenced become. Many of these characteristic properties that influence the surface are very closely related to the local distribution of moisture and bulk density.

All processes for the thermal-mechanical surface forming of flat material webs, Paper and cardboard in particular are based on the principle of simultaneous action or immediately successive exposure to heat and pressure deforming flat material when passing the web between two or more rollers different surface properties, hardness and elasticity. This is often a thermal-mechanical process Surface treatment a moist pre-treatment of the sheet to be deformed ahead, whereby the pre-wetting can be done by water or steam. Dependent on the type of paper or cardboard quality, the required surface quality and production speed for this smoothing units, calendering calenders, hot gloss presses, smoothing cylinders, Soft calenders and similar devices used.

However, the known methods for thermal-mechanical surface treatment have significant disadvantages that arise from the fact that when heating the materials higher temperatures the melting or softening temperatures of components of the treating material can be achieved. This leads to partial adhesion or completely sticking the material webs to the surfaces of the above Aggregates, e.g. B. rollers, so that it is not possible, for example in terms of Heat supply and production speeds achievable aggregate conditions for to use a rational production flow.

These disadvantages occur particularly in the production of coated papers with high Latex components in the pigment line, with surface-sized or coated papers Water and / or heat-sensitive binder components as well as latex-reinforced, latex-impregnated or latex-coated and synthetic fiber-containing special papers, whereby it, for example, at a certain temperature and / or throughput speed Disruptions to the production process in the manner specified.

The use of means to reduce adhesive forces between each other bordering surfaces (so-called abhesives) is known. For this, silicones, Oil-in-water emulsions, metal soaps, waxes and especially paraffins and talc are used. When processing thermoplastics, these substances are used to form films Tetrafluoroethylene polymers used as antiblocking agents. In the food industry is the use of separation emulsions based on oil-in-water emulsions known from self-emulsifying fatty acid mono- and triglycerides.

According to this status, anionic co-emulsions are produced according to EP 0 478 177 A1 Carnauba wax and paraffin wax are used as antiblocking agents in cardboard production.

The abhesives mentioned so far are for thermal-mechanical surface treatment not suitable because they are either insufficiently effective or not procedural, for example, without affecting the desired surface quality of the products can be.

The patent DE 43 01 677 C2 is used to improve the printability of plastic films for the furniture industry in the production of thermoplastic laminating films on calenders proposed the use of certain ethylene-acrylate copolymers.

In DE 44 12 624 A1, paper production is covered with satin in an off-line calender described, in which the material web wound on a roll in the meantime for uniform treatment and improvement of printability in a temperature and / or Moisture-controlled ambient atmosphere is stored.

Compositions are also known from EP 0 648 820 A2 which are used to remove Toning of paper surfaces, adhesive residues of plastics, for removing plastic coatings and for cleaning metal surfaces from cutting oil residues or colored pencil markings used, as well as used to remove PVC parts attached by adhesives become. Concentrated oil-in-water emulsions are used non-aqueous phase of 8-90% by weight, the most diverse organic compounds, as well as dicarboxylic acid diesters, and those with the partial use of ultrasound and other auxiliary materials (unwoven fabric strips) in the temperature range of 5 - 70 ° C, partially with additional heating of the cleaning agent during the cleaning process be used. The emulsions also contain solvents such as isopropanol, Toluene, benzyl alcohol, methyl ethyl ketone, N-methyl pyrrolidone, di- and triethylene glycol dimethyl ether as well as 3-methyl-3-methoxybutanol, which are the use of these emulsions in closed systems for reasons of occupational safety and health risks limit.

German patent application P 195 19 268 relates to the use of compositions those for cleaning machine and plant parts in the production of pulp, Paper, cardboard and cardboard as well as to prevent contamination by adhesives and adhesive resins on such aggregates are used as emulsions and as Part of the oil phase saturated or unsaturated fatty acids monoalkyl esters and monooder Polyester of a saturated or unsaturated mono- or polyvalent carboxylic acid with 2 contain up to 30 carbon atoms and polyols.

EP 0 529 385 B1 describes a method for producing smoothness and / or gloss on paper surfaces described in which after heating and pressurizing the paper web is subjected to a shock treatment to fix the gloss and smoothness of the surface the preformed fibers.

Furthermore, from the publication by F. Debuan and P. Hänßle in Erdöl & Kohlen, Erdgas, Petrochemie 37 , Heft 11, pp. 511 to 514 (1984), the use of aliphatic dicarboxylic acid esters because of their high temperature viscosity, the low tendency to evaporation and resistance to oxidation as a component known for synthetic lubricating oils, it being found that dicarboxylic acid esters cover the metal surfaces in internal combustion engines and improved piston cleanliness is achieved.

In US 4,776,970 lubricants with a separating effect for use in the Paper coating, especially when printing on paper, describes the fatty acid esters of C11-C21 fatty acids with C12-C22 alkanols and as an additive to the coating as well as for calendering in the temperature range of 40-100 ° C. The comparatively tested ethylene glycol distearate shows a lower effectiveness against the fatty acid esters described.

Similarly, according to Römpp, 9th edition, p. 5019 (1992), the use is more specific Dicarboxylic acid esters, especially adipic acid, phthalic acid, sebacic acid and Azelaic acid known for the production of plastic products and films.

The object of the invention is therefore, the adhesion effects, in particular that Gluing material webs to device parts of units such as rollers and Pressing tools in the thermal-mechanical surface treatment of sheet-like materials, especially paper and cardboard webs reduce or avoid, so the production of such webs with to enable improved surface properties and at the same time the existing process engineering options in the production of such better use of sheet-like materials, i.e. z. B. with higher throughput speeds and to be able to work at higher temperatures.

This object is achieved by the use of agents which are dialkyl dicarboxylates and / or esters of saturated and / or unsaturated C8-C18 Fatty acids with glycers and / or one and / or polyunsaturated CI6-C22 Contain fatty acids as an abhesive component.

The invention accordingly relates to a method for thermal mechanical Surface treatment of paper and cardboard webs, preferably with one Water content below 50% by weight, by simultaneously or immediately successive exposure to heat and pressure to produce special paper and cardboard qualities, using at least one Abhesive, which is characterized in that the abhesive Dicarboxylic acid dialkyl esters and / or esters of saturated and / or unsaturated C8-C18 fatty acids with glycerin and / or mono- and / or polyunsaturated C16-C22 Contains fatty acids.

It has been found that dicarboxylic acid esters, esters of unsaturated and / or unsaturated C8-C18 fatty acids with glycerin and unsaturated C16-C22 fatty acids a surprising abhesive effect on the thermo-mechanical Perform the machining process so that the materials stick to parts of the device, how heated roller or press surfaces are reduced or completely omitted.

The use of the agents according to the invention is particularly in the production of paper and Cardboard webs and especially in the production of surface-treated special papers as well as for coating, smoothing or satinizing.

The abhesive agents to be used according to the invention are preferably dicarboxylic acid esters Dicarboxylic acid dialkyl and / or diisoalkyl esters of C2 - C12 dicarboxylic acids with C1 - C13 n- and / or iso-alkanols, such as di-n-butyl oxalate, di-n-butylmalonate, di-n-butyl succinate, din-butyl glutarate, Di-n-butyl adipate, di-n-butyl suberate, di-n-butyl sebacate, dimethyl adipate, diethyl adipate, Di-n-propyl adipate, diisopropyl adipate, diisobutyl adipate, di-tert-butyl adipate, diisoamyl adipate, Di-n-hexyl adipate, di- (2-ethylbutyl) adipate, di- (2-ethylhexyl) adipate, diisodecyl adipate, Dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, Di- (2-ethylhexyl) phthalate and diisodecyl phthalate and the diesters of C9 dicarboxylic acid (Trimethyladipic acid) and dodecanedicarboxylic acid.

Esters of saturated and / or unsaturated C8 to C18 fatty acids are also to be used with glycerin, z. B. glycerol mono- and / or glycerol di- and / or Glycerintrifettsäureester.

The esters of adipic acid or sorbitan are preferably used and particularly preferably the adipic acid esters of C1 to C6 n- and / or iso-alkanols, such as dimethyl adipate. Diethyl adipate, di-n-isopropyl adipate and diisopropyl adipate, di-n-butyl adipate and / or Diisobutyl adipate, as well as glycerol trioleate and the mixed esters from the above Dicarboxylic acids and different C1 - C6 n- and / or iso-alkanols.

The unsaturated fatty acids to be used as abhesive agents according to the invention are unsaturated C16 - C22 carboxylic acids, preferably oleic acid, linoleic acid, linolenic acid, Eleaostearic acid and 5, 9, 12 octadecantrienoic acid, which as mixtures in vegetable and Animal oils occur and are known for example as tall oil fatty acids.

The esters and unsaturated fatty acids are directly or as diluted or concentrated water-containing or water-free solution or in the form of water-containing dispersions used. Suitable solvents are n- and iso-alkanols, liquid hydrocarbons, Acetone and other known solvents, especially natural oils or modified natural oils, such as beet oil methyl ester.

The abhesive ester and unsaturated fatty acids can be used alone or in combination with such water-soluble or water-insoluble solvents to form emulsions dispersed, non-ionic, ionic and amphoteric. in particular nonionic and anionic surfactants can be used as emulsifiers.

Suitable nonionic emulsifiers are, for example, oxalkyl ethers, preferably Oxethylates and / or terminally blocked oxethylates of fatty alcohols and fatty acids or Oil. Anionic emulsifiers are alkyl and / or aryl sulfonates, α-olefin sulfonates, α-sulfo fatty acid esters, Sulfosuccinic acid esters as well as alkyl sulfates and ether sulfates as well carboxymethylated oxethylates and soaps. The production of the preferably stable emulsions are known. For example, the hydrophobic Phase, which contains the abhesive component, entered in the aqueous emulsifier-containing phase and dispersed with stirring or pumping.

According to the invention, the thermally stable abhesive agents according to the invention can be applied directly the surfaces of the devices, e.g. B. applied by rollers and and presses, but they can also impregnating liquid or paper coating or added to the dampening water or steam during the pre-moistening or, preferably shortly after the impregnation or application plant or directly in front of the smoothing roller on the finished paper web be applied.

The abhesive agent according to the invention is preferably the superheated steam for steam humidification, preferably continuously, metered in, the volatile abhesive, for example dissolved in a water-miscible solvent such as ethanol, isopropanol or acetone is metered in.

The amount of the abhesive used can be determined by the amount applied to the surfaces of the devices, e.g. B. from rollers and presses, depending on the required effect, the desired temperature increase or other process measures. Usually 0.1 to 10.0 g / m ² , preferably 0.1 to 5 g / m ^{2 of} the abhesive is applied to the surface of the aggregate. When metering into the superheated steam line, 0.1 to 10.0 kg / hour. Abhesive, preferably 0.2 to 4.0 kg / h. Abhesive added to the steam. The amounts given relate in each case to the active substance of an anti-abhesive composition.

According to the invention, the abhesive agents can also be used as a mixture or as a mixture with known ones Abhesives are used.

The use of the compositions according to the invention makes pigment-coated papers more significant Improvement of the surface properties, especially the smoothness, the gloss and the micro-roughness, while the bulk density of the paper web remains unchanged. The paper properties of the papers treated according to the invention reach during processing almost one level of quality in one process step, previously only possible through two Soft calendering was possible.

In the manufacture of furniture pre-impregnates, the gloss is evident after painting improved without a negative influence on the wettability compared to aqueous and / or solvent-based gravure inks. Likewise, gravure printing is not essential changed.

In the inventive production of sheet-like material webs according to the invention The use of the abhesive agents will significantly improve other products Preserve properties: For example, when manufacturing from both sides latex-impregnated and one-sided latex-coated, flexible abrasive base paper the abhesive applied to heated steel rollers, causing an increase in surface temperature values of over 70 ° C is possible without adhesive effects. The temperature increase results in a smoothness increase of approx. 80%, a decrease micro roughness and a reduction in thickness and a reduction in rigidity reached.

Similar advantages are obtained when using the agents according to the invention the production of surface pigmented silicone base papers.

The invention is illustrated by the following examples; here the substance-related Percentages in each case on the weight of the components.

example 1

Strips of approx. 20 cm width and approx. 80 cm length of a 120 g / m ² abrasive base paper impregnated with latex on both sides and then coated on one side with a total latex of approx. 25% and an equilibrium moisture content of approx. 6% in a two-roll laboratory calender from Fa Kleinewefers AG, D-47803 Krefeld, smoothed with the highest possible line pressure and increasing temperature of the heated steel roller. The counter roll was a cotton hard paper roll analogous to a conventional hard nip calender construction.

Already at a surface temperature of the steel roller of approx. 60 ° C there was a slight sticking the paper web on the roller, which was observed increasingly at about 70 ° C.

When applying the thermostable abhesive agent according to the invention, consisting of 1.85 Parts by weight of a nonionic vegetable oil ethoxylate, 17.1 parts by weight of water and 3.1 parts by weight of di-n-butyl adipate, on the heating roller (steel) and further heating the The heating roller did not strongly adhere the paper web to the steel roller until the surface temperature from 150 ° C. In comparison between untreated and treated Heating roller had the effect of sticking when using the abhesive only after a temperature increase of over 70 ° C. The way of working possible in this way with increased heating of the material web, the smoothness increased by approx. 755 Bekk-s to approx. 1180 Bekk-s, a reduction in micro-roughness (Parker Print Surf) from approx. 2.8 µm to approx. 2.4 µm, a reduction in thickness from 124 mm to 118 mm and a Reduction of rigidity from 227 mN to 212 mN.

Example 2

A latex-impregnated and coated abrasive base paper of 120 g / m ² according to Example 1 was moistened to approx. 13%, stored in a closed plastic bag for approx. 1 hour for the purpose of uniform moisture distribution and then satinized. While the paper web again began to stick strongly at a surface temperature of the untreated steel roller above 60 ° C, the adhesive of the paper web to the steel roller treated with the thematically stable abhesive agent according to Example 1 only occurred at a surface temperature of approx. 140 ° C, the improvements Due to the higher moisture content of the paper webs before the satin finish (13%, instead of 6% in Example 1), the surface properties of the processed abrasive base paper was even clearer than the improvements described in Example 1.

Example 3

The latex-impregnated and -coated abrasive base paper of 120 g / m ² , according to Examples 1 and 2, was calendered in a pilot plant smoothing machine with maximum possible line pressure and the lowest possible web speed of 5 m / min and with increasing warming to temperatures up to a maximum of 200 ° C subjected to the surface of the steel roller. The counter roll had a fiber / plastic cover of 91 ° Sh D hardness analogous to a soft calendar construction.

The calendering was carried out with a moisture content of the paper samples of 7.7 and 9.7%. at Heating roller surface not treated according to the invention already occurred at a surface temperature from 70 ° C a slight sticking or with the paper sample with a higher moisture content a strong sticking on. None could surface temperatures of over 80 ° C of the two pre-moistened papers can be adjusted because the sticking effect Wrinkling in the paper web led.

After a surface treatment of the heating roller with the thermally stable abhesive according to Example 1 could not visually stick the paper webs at the maximum possible Surface temperature can be determined. By increasing the temperature from 80 to 200 ° C a smoothness increase of approx. 80% and a reduction in micro-roughness on the abrasive base paper (Parker Print Surf) achieved by approx. 25%. The reduction in thickness and rigidity were in the range of the values of Example 1.

Example 4

Strips approx. 20 cm wide and approx. 80 cm long of a furniture film of 70 g / m ² pre-impregnated with a mixture of latex and urea-formaldehyde resin and having a latex / resin content of approx. 30% were heated in a two-roll calender according to Example 1 the steel roller is smoothed to the maximum possible surface temperature of 150 ° C. Previously, the paper had been brought to different moisture contents of 2.5%, 6.4%, 7.1% and 9.4% and then stored separately in a sealed plastic bag for 1 hour.

During calendering, the surface of the heating roller was half covered with a thermo-stable one Abhesive, consisting of 4.2 parts by weight of di- (2-ethylbutyl) adipate, 23.2 Parts by weight of water and 2.5 parts by weight of a nonionic surfactant, treated.

When calendering, the paper samples stuck on from a web moisture of 7.1% on the untreated roller surface, while on the surface treated Even at the highest web moisture of 9.4%, the roll side does not stick to the paper webs was found.

Example 5

The experiments were repeated analogously to Example 4 with a pre-impregnated furniture film of 80 g / m ² , but with a very high filler content, the individual samples again differing in moisture content of 2.5%, 5.8%, 6.4% and 8 , 5% were set. During calendering, the untreated steel roller with a surface temperature of 150 ° C already showed 5.8% sticking effects on the sample with a humidity, which became increasingly stronger in samples with higher web moisture. On the surface treated with a thermally stable abhesive, consisting of 4.2 parts by weight of diisodecyl adipate, 23.2 parts by weight of water and 2.5 parts by weight of a nonionic surfactant, a light surface only became visible at a web moisture of 8.5% Sticking noted.

Example 6

The experiments were repeated analogously to the conditions of Example 4 with samples of a silicone base paper of 62 g / m ² pigmented on one side. The coating was 5 g / m ² with a very high latex content of over 40%. The samples were pre-moistened to 4.5%, 8.1%, 9.2% and 12.0% respectively and again stored separately. After heating the steel roller to the maximum possible surface temperature of 150 ° C, a slight sticking occurred on the untreated roller side at 12%. On the steel roller treated with a thermally stable abhesive, consisting of 5.46 parts by weight of trimethyladipic acid C _8/10 aluminum foil, 25.0 parts by weight of water, 5.2 parts of isopropanol and 3.3 parts by weight of a nonionic surfactant no sticking of the paper found, even at the highest web moisture.

Examples 7 to 12

In a heated laboratory calender according to Example 1, sandpaper was applied with a finish at a line pressure of 400 bar satin, the surface of the steel cylinder on Temperatures of 70 ° C or 130 ° C was set. Various abhesives were used tested in the form of an oil-in-water emulsion, with the abhesive on the surface by rubbing in the heated steel cylinder. The emulsions were from 2.0 parts by weight of a fatty alcohol oxyethylate, 11.6 parts by weight of water and 1.3 Parts by weight of the abhesive component are formed. The adhesive behavior during calendering as well as the flatness of the satin paper with the features: easy rolling (+), almost level flatness (++) and ideal flatness (+++) assessed. When sticking (+) the paper on The surface of the roll was twisted to a crepe paper-like state.

The results are summarized in Table 1 below : example abhesive Adhesion behavior at Flatness at 70 ° C 130 ° C 70 ° C 130 ° C 7 tall oil fatty acid ++ + 9 glycerol trioleate ++ ++ 10 Di-n-butyl phthalate + + 11 Diisononylphthalat + + 12 Di-n-butyl adipate +++ +++

Example 13

It was examined whether the surface properties when using the thermo-stable abhesive of papers with regard to wetting with water, water-based paints or aqueous gravure inks.

For this purpose, the abhesive was applied in a ratio of 1 to a furniture pre-impregnate according to Example 4: 1 or 1:10 diluted with water using a laboratory doctor applicator and then in a two-roll laboratory calender, according to Example 1, with the highest possible Line pressure and a surface temperature of the heated steel roller of 150 ° C satin.

The smoothness level of the paper samples thus satin was 300 ± 30 Bekk-s smoothness. As a comparison sample was also a laboratory-patterned paper sample with approx. 300 Bekk-s, but without used this surface application. The data in Table 2 show that the The abrasive agent did not significantly change the contact angle to the water in the satined sample is, while the gloss after painting by using the abhesive a significant improvement is achieved in a 1: 1 mixing ratio with water. The gravure printability is changed insignificantly compared to the comparison sample.

The experimental data further show that the paper which has been surface-treated with thermally stable abhesive agents is not impaired in terms of water wettability and is in some cases even somewhat improved. In the same way, no significant difference in the wetting behavior of the papers was determined compared to solvent-based printing inks. For further comparison, the data of an unsmoothed paper (blank sample) and a paper produced in production are given in Table 2. Properties of furniture pre-impregnates, 70 g / m ² after different surface treatment Example 13 Contact angle, degree Gloss (75 °) (aqueous after SH coating),% Printability (laboratory gravure, watery), grade laboratory calender - without abhesive 102.9 59.2 2 - with abhesive Diluted 1: 1 102.8 64.5 3 Diluted 1:10 104.4 52.8 4 Blank sample (without abhesive) 105.6 45.3 5 Soft nip calender (without abhesive) 92.4 71.4 1

Example 14

Geschwindigkeit: 500 m/min

Liniendruck: 400 kN/m²

beidseitige Dampffeuchtung vor 1. Durchgang

Oberflächentemperatur der Heizwalze (unten)

1. Durchgang 120 °C bzw. 160 °C

2. Durchgang 160 °C

A one-sided pigment-coated paper of 50 g / m ² (base paper, Vers.-Nr. 200) was smoothed in a technical smoothing machine (soft calender: steel / plastic roller) under the following practical conditions:

Speed: 500 m / min

Line pressure: 400 kN / m ²

Steam humidification on both sides before 1st pass

Surface temperature of the heating roller (below)

1st pass 120 ° C or 160 ° C

2nd pass 160 ° C

The completely volatile abhesive consisting of a 10% solution of di-n-butyl adipate in isopropanol was continuously introduced into the at a dosage of 1 l / h Heating steam line introduced for the lower steam humidifier.

The experiment was carried out in the sub-steps of version no. 201 to version no. 204 performed. in this connection as much steam should be applied to the paper web before the first pass until an increasing occupancy of the heated smoothing roller (steel) was observed.

In experiment 201 2 x 58 kg steam / hour at 120 ° C. be applied before it came to cover the heating roller. In experiment 203, the addition of the fiction The abhesive agent according to Example 1 has a maximum possible amount of steam of approx. 110 kg steam / hour be applied without the roller being loaded. simultaneously however, the final moisture content of the paper also increased by approx. 0.5% (absolute), making it easier Drop in the values of the surface properties occurred. Trial 204 failed Use the abhesive at an elevated roller temperature of 160 ° C the paper web with a maximum possible amount of steam of 170 kg steam / hour. (total) applied without any deposits on the smoothing roller.

By increasing the temperature by 40 ° C and at the same time increasing steam absorption of 54 kg / h (overall) was a significant improvement in surface properties of paper in terms of smoothness, gloss and micro-roughness, while the bulk density remains unchanged remained.

The paper properties almost reach a quality level that has only been achieved twice before Soft calendering (version no. 202) was reached.

The test data and paper properties after soft calendering with and without the use of the abhesive agent are listed in Table 3 for comparison. Soft calendering of thin paper P, 50 g / m ² Vers softcalender VIB-Gloss Profiler amount of steam in kg / h paper properties nip Temperature ° C above below Final moisture,% Gross density, g / cm ³ Gloss (75 °),% PPS µm Smooth Bekk-s 200 (base paper) 0 - - - 5.0 0.80 7 7.56 11 201 1 x 120 58 58 6.7 1.02 32 3.36 229 203 1 x 120 58 110 *) 7.2 1.01 28 3.53 197 204 1 x 160 80 90 *) 5.1 1.02 38 3.09 288 202 2 x 120/160 58 58 6.2 1.04 40 2.87 347 (1st round)

Claims (12)

1. Process for thermomechanical surface treatment of paper and board webs by simultaneous or simultaneously successive action of heat and pressure to produce specific paper and board grades by using abhesive agents to reduce or avoid web adhesion to thermomechanical surface treatment assemblies, characterized in that at least one abhesive agent used contains dialkyl dicarboxylates and/or esters of saturated and/or unsaturated C₈-C₁₈-fatty acids with glycerol, glycerol trioleate and/or mono- and/or polyunsaturated C₁₆-C₂₂-fatty acids as an abhesively active component.
2. Process according to Claim 1 for producing furniture preimpregnates, latex-reinforced, latex-impregnated or latex-coated and synthetic-fibre-containing specialty papers or slip-coated papers having high latex fractions in the pigment slip.
3. Process according to Claim 1 or 2, characterized in that an abhesive agent used contains dialkyl and/or diisoalkyl esters of C₂-C₁₂-dicarboxylic acids with C₁-C₁₃n- and/or iso-alkanols as an abhesively active component.
4. Process according to Claim 3, characterized in that the dialkyl and/or diisoalkyl dicarboxylates used are adipic diesters of C₁-C₆n- and/or iso-alkanols.
5. Process according to Claim 1, characterized in that an abhesive agent used contains linoleic acid, linolenic acid, eleaostearic acid and 5,9,12-octadecanetrienoic acid as unsaturated C₆-C₂₂ fatty acids.
6. Process according to any of Claims 1 to5 , characterized in that the abhesive agent is used as an oil-in-water emulsion.
7. Process according to any of Claims 1 to6 , characterized in that the abhesive agent is applied to the surface of the thermomechanical treatment assembly or is added to the impregnating liquid or to the paper-coating composition or to the moistening water or to the steam in pre-moistening or is applied to the paper web preferably shortly after the impregnating or coating unit and directly before the smoothing roll.
8. Process according to Claim 7, characterized in that the abhesive agent is water vapour volatile and is metered directly, preferably continuously, through the steam line for steam moistening.
9. Process according to Claim 8, characterized in that the abhesive agent is used in amounts of 0.1 to 10.0 g/m² of assembly surface, based on active substance in the abhesive agent.
10. Process according to Claim 9, characterized in that the abhesive agent is added to steam in amounts of 0.1 to 10.0 kg/h and preferably 0.2 to 4.0 kg/h, based on active substance.
11. Process according to Claim 7, characterized in that the oil-in-water emulsion of the abhesive agent contains a nonionic, anionic or amphoteric emulsifier, preferably a nonionic or anionic emulsifier.
12. Process according to any of Claims 1 to 11, characterized in that the paper or board webs have a water content of below 50% by weight.