NO154529B - COMPLETELY DRY-REMOVABLE WALL COVERINGS. - Google Patents

Description

The object of the invention is dry-removable, optionally adhesive wall covering whose back side is equipped with a hydrophobic multi-component layer, and optionally a water-activatable adhesive material layer.

Hydrophobing of wall coverings, especially wallpaper, belongs to the state of the art. According to German patent 1 635 623, a textile web is hydrophobicized using wax containing zirconium salts. In another work process, a cationic acrylate resin emulsion is then applied in an amount of 100-150 g/m 2 to the weave to achieve a textile wallpaper that is dimensionally stable against water, respectively water vapor and mechanical influences. After application of the water-activatable adhesive layer, a directly stickable, but in a completely dry state, peelable wallpaper is indeed obtained.

The dry-removable wallpapers on the market are also equipped with a hydrophobic layer on the back to ensure their dimensional stability when pasted. These wallpapers, however, must swell for at least 15 minutes after being coated with commercially available wallpaper adhesive, as otherwise sufficient adhesion of the wallpapers will not be achieved. This swelling time can be greatly shortened when a wallpaper raw paper is equipped with the hydrophobic layer according to the invention.

The invention relates to completely dry-removable, optionally adhesive wall coverings whose back side is equipped with a hydrophobic multi-component layer, and optionally a water-activatable adhesive material layer, the wall coverings being characterized by the fact that the multi-component layer is composed of

1) 30-85% by weight of a copolymer made up of

a) 25-75% by weight vinylidene chloride units,

d) 10-50% by weight ethyl acrylate units, and

c) 10-50% by weight methyl acrylate units,

2) 0-40% by weight of a copolymer made up of

d) 8 5-6 5% by weight alkyl acrylate units:, - and

e) 35-15% by weight monoolefin units,

3) 15-70% by weight of a conventional wax with a solidification point of at least 40°C (according to DIN 51556), 4) 0.05-2.5% by weight of a conventional impregnating agent,

5) 0.05-5% by weight of conventional coagulant,

6) 0-5% by weight of a conventional thickener,

whereby the sum of l)-6), a)-c) and d) + e) each amounts to 100% by weight.

The hydrophobic multi-component layer is preferably applied as an aqueous dispersion to the wall covering, preferably to wallpaper and paper, with the solid parts of the component in the dispersion corresponding to the weight % stated above. Known application units are wind brush, squeegee, roller or glue press. In preliminary trials, it is easy to determine which concentration, respectively viscosity, is most suitable for the relevant application system. Preferably, the coating should have 1-10 g/m 2 , preferably 3-7 g/m 2 of the hydrophobic layer on the back. Too strong, machine-dependent foam formation can be avoided by using suitable foam barriers.

After application of the dispersion, the paper web is dried with drying apparatus (e.g. drying channel with IR or gas jets, heated rollers).

The thus hydrophobicized wall covering, preferably wallpaper raw paper, can be printed according to known methods, and glued with commercially available adhesive.

Thereby, in the case of the known, completely dry-removable wallpapers, it was necessary to let the pasted-on wallpapers swell for at least 15 minutes in order to achieve the necessary "softness" with a wet leather cloth on the wallpaper. Only then can it be glued.

As the impact time cannot be determined absolutely precisely, the paper and wallpaper industry uses the Cobb-Wert method according to DIN 53 132 to obtain an objective measure

for the impact time. The Cobb value is a measure of the water absorption capacity of a paper per unit of time and area. The larger this value is, the faster the paper absorbs water, and the faster the desired so-called "softness" of the paper is achieved. In the case of the previously known completely dry-removable wallpapers

after a three-minute exposure time, a Cobb value of approx. 20. In contrast, the wall coverings equipped according to the invention succeeded, after the three-minute exposure time, already in achieving a Cobb value of 30-70.

A water-activatable adhesive can also be applied to the hydrophobic layer to obtain adhesive wall coverings. The adhesive is preferably applied in amounts of 5-15 g/m 2 , particularly preferably 7-12 g/m 2 . The applied adhesive is dried in known drying devices.

You thus get a wallpaper that only needs to be pulled through a water bath, in which it stays for a short time to stick, and later in a dry state can be easily pulled off.

The copolymer used to produce the hydrophobic layer is produced according to known methods. Preferably, it should have a molecular weight of at least 50,000.

The copolymer 2) is preferably made up of alkyl acrylate with C-^-C^ in the alkyl radical, particularly preferably of methyl acrylate or ethyl acrylate and of aliphatic monoolefins with C^-C^ or aromatic monoolefins, preferably

show the board.

Commercially available waxes are used as wax, preferably those with a solidification point of at least 40°C (according to DIN 51556) in the form of dispersions. Particularly preferred is a wax dispersion with a density of 0.945 to 0.97 g/cm<3> at 15°C, "MOBILCER", is particularly preferred.

As impregnating agents, conventional fluorinated polymers on a polyacrylate basis, known as impregnating agents, are preferably used.

It is particularly preferred to use "Scotchban" FC 824, a

40% by weight aqueous emulsion of a fluorinated polymer compound for the production of the hydrophobic layer.

The silicone compounds commonly known as coagulating agents, preferably siloxanes with polyoxyalkane groups, are introduced into the dispersion used for coating. "Tegopren" 100 is particularly preferred.

Preferably, thickeners of the substance class cellulose ether, polyvinyl alkyl ether-maleic acid ester, poly-alkylene oxides, polyvinyl pyrrolidone copolymers can be used.

As an adhesive, the usual wallpaper adhesives can be used

based on cellulose ether. Suitable cellulose ethers are e.g. methyl cellulose and carboxymethyl cellulose.

The measurement data listed in the examples were determined as follows: The wallpaper is coated with a 2% by weight aqueous adhesive solution. The time that elapses from coating to softening of the wallpaper is measured.

2. Cobb value:

The test procedure serves to determine water absorption

of paper, solid cardboard and corrugated cardboard, each time from one side (top and bottom) and referred to in DIN regulation 53 132.

The amount of water in grams that is absorbed by 1 m<2> paper surface on one side after an exposure time t (t = 3 min.) is determined. After storage in a standard climate of 20°C and 65% relative humidity (DIN 50014), the paper sample is exposed to water in accordance with the standard. The water absorption is determined by the difference before and after the impact of water, and is converted to the plate of 1 m 2.

3- Withdrawal force:

The pull-off force is used to assess the adhesion of the wallpaper to the substrate. A pressure and tension force meter type 901-001 was used.

The wallpaper pattern, which is glued to a flat surface and dried for 2-3 days in the air, has a width of 29 cm and a length of 39 cm. The narrow side of the wallpaper leaf is detached 4-8 cm from the substrate, and placed around a metal rod with a hole in the middle, and the upper paper end is glued with an adhesive strip to the wallpaper and paper sticking to the substrate.

At the point where the metal rod has holes, the paper is pushed through, and the extraction device is engaged.

Pulling off the 39 cm long sample takes place at an angle

at 90° to the wall.

The resulting pulling force is read on the above-mentioned pulling device and recorded.

It has been shown that values < 1 kp mean too easy withdrawability. For values > 1 kp, it has been established that good drawability is achieved.

The following substances are used for the production:

"Mobilcer C": 46% by weight wax dispersion with a density

of 0.955 g/cm<3> (15°C).

"Scotchban" FC 824: 40% by weight aqueous emulsion of a fluorinated

polymer compound. Density: 1.13 g/cm 3. "Tegopren" 100: Solid (100%) of an organic solvent in water in completely soluble

3 silicone compound. Density: 1.0 g/cm

(250°C).

"Walocel" MV 40,000 GB: Methyl cellulose (100%).

"Borchigel L 75": 50% by weight aqueous solution of a non-ionic polyurethane-based thickener.

"Thickner L": 15% by weight aqueous thickener solution of polymeric alkyl vinyl ether/maleic noble esters.

"Polyox WSE 750": 100% by weight solids based on polyethylene oxide.

"Waloran": 50% by weight aqueous copolymer dispersion based on vinylidene chloride, ethyl acrylate

and methyl acrylate.

"Acronal" 170 D: 45% by weight aqueous dispersion of et

acrylate/styrene polymer.

"Ukaphob B 486": Approx. 30% aqueous dispersion for hydrophobicizing wallpaper raw paper.

"Auroplex": Wallpaper tread paper.

"Valocel CT 30G01": Carboxymethylcellulose

Examples:

Eczemagel_l:

a) The manufacture of the dispers ion

The following amounts of material are prepared in storage vessels A to E:

The dispersion's solids make up 42.92% by weight.

The contents of storage containers B, E, A,

C and D while stirring in a 5 liter mixing vessel, as with increasing volume and increasing viscosity, the speed of the stirring blades is increased so that a good mixing of the individual components can take place.

After a further stirring time of 10 minutes, the homogenization of the mixture is finished.

<b>) E2E§Ebeidelse_av_disgersjonen

The dispersion prepared under point a) is applied over

a conventional roller application system the wallpaper raw paper "Auroplex" and is then dried in a drying channel. To pass through a cooling roll station, the coated paper is wound up.

c) Examination se_av_de t_bela2te_ tap_e trågair When liquidating the paper rolls manufactured under point b)

attention is paid to possible block conditions (gluing and bonding properties of the individual paper layers with each other).

Blocks cannot be determined. The block ratio is described as good.

The 3-min Cobb value was determined to be 50.

One sheet of embossed or unembossed coated raw paper of size

39 x 28 cm is coated each time on the back with an adhesive solution (diluted 1:50) of "Walocel Universal" with a brush. The exposure time was 5 minutes. The paper sheet was then glued to an Eternite wall. The adhesion was good. After two days of drying, the pattern leaves completely

and dry pull off. With unembossed paper, a pull-off force of 1.9 was measured and with embossed paper one of 2.9 kp. Overall rating: Very good.

Example_el_2-5:

Examples 2-5 and the comparison example have been carried out analogously to example 1, and the necessary data listed in the following table 1.

Example_el_6-9:

Analogous to examples 1-5, a wallpaper raw paper was hydrophobicized, this layer being applied in an amount of 4.8-6.0 g/m 2.

Embossed and unembossed wallpaper paper is then coated on the coated side with a 14% by weight "Walocel CT 30G01" solution at a speed of 2.5 m/min. in a roller application system, dried in a drying channel and wound up. The adhesive uptake amounted to 8-12 g/m<2>.

Coated, embossed and unembossed paper patterns of size

39 x 29 cm, dipped in water for 8 seconds. Excess water is allowed to drip off for 20 seconds and the paper sheet is glued to an eternite wall. After a two-day drying time, the pattern can be completely and dry removed. Thereby, a pull-off force of 1.5-2.3 kp was measured for unembossed paper, and one of 2.5-3.8 kp for embossed paper.

Overall rating: Very good.

The measured values in examples 6-9 and the comparison example

B is listed in table 2.

Claims (6)

1. Completely dry-removable, optionally adhesive wall coverings whose back side is equipped with a hydrophobic multi-component layer, and optionally a water-activatable adhesive material layer, characterized in that the multi-component layer is composed of 1) 30-85% by weight of a copolymer made up of a) 25-75% by weight vinylidene chloride units, b) 10-50% by weight ethyl acrylate units, and c) 10-50% by weight methyl acrylate units, 2) 0-40% by weight of a copolymer made up of d) 85-65% by weight alkyl acrylate units, and e) 35-15% by weight monoolefin units, 3) 15-70% by weight of a conventional wax with a solidification point of at least 40°C (according to DIN 51556), 4) 0.05-2.5% by weight of a conventional impregnating agent, 5) 0.05-5% by weight of conventional coagulant, 6) 0-5% by weight of a conventional thickener, whereby the sum of l)-6), a)-c) and d) + e) each amounts to 100% by weight. 2. Wall covering, especially paper wallpaper, according to claim 1, characterized in that as component 4) a fluorinated polymer compound is used and as component 5) an organic silicone compound. 3. Wall covering according to claims 1 and 2, characterized in that the hydrophobic layer is applied in an amount of 1-10 g/m 2, and the possible adhesive in an amount of 5-15 g/m 2.