DE1594057A1 - Adhesive strips or separating foils with separating layers and with non-porous films as carriers - Google Patents

Description

PATENT ADVOCATE DR. HANS.-GUNTHER EGGERT, DIPLOMA CHEMIST

5 COLOGNE UNDENTHAI. PETBR-KINTGEN-STRASSE 8 1594057

^ "^ -" · "~ 'Eg / Dr / La

Cologne, August 20, 1965

JUr "' ^T

Johnson & Johnson, 501 George Street, New Brunswick,

N.J. (V.St.A.)

Adhesive strips or release films with release layers and with non-porous films as a carrier

The present invention relates to sheets and strips comprising a thin, flexible film or sheet of non-porous material; such as acetate cellulose, regenerated cellulose, Polyethylene terephthalate or the like have as a carrier, in particular strips in which one side of this Carrier is provided with a layer of a pressure-sensitive adhesive.

Self-adhesive tapes are commonly wound into rolls manufactured and put on the market. When using the strip, it should therefore be possible to use a piece of the strip without applying excessive force, without gluing the backing, removing the adhesive or the like from the Unwind roll, regardless of the time and the conditions under which the roll of adhesive tape before this Use 'has been kept.

For these reasons it is necessary to provide the back of the strip with a layer called a release layer, which has the purpose of reducing the forces necessary for unwinding the roll. The adhesive layer comes in the roll the one layer of strips in direct contact with the back of the inside of the roll below Strip layer. Without a separating layer on the back, the

009832/1608

Adhesive come into direct contact with the carrier. Due to the properties of the carrier and the adhesive could however, there is generally an excessively strong bond between the two, so that an extraordinary one Force is required to unwind the roll.

Separating layers are used to reduce the force required to unwind the roll. These are layers applied to the back of the strips to which the pressure-sensitive adhesives only have a low level of adhesion. Various types of release agents have been used in such layers. According to US Pat. No. 2,032,845, wax is used in such layers. Various soaps and other surfactants are recommended for this in U.S. Patent 2,358,831. Materials are also already known which - such as the Werner ¹ see chromium complex of stearic acid, which is described in US Pat. No. 2,803,557 - are polymerized after application. Many polymers with separating properties have also been recommended, for example copolymers of octadecyl acrylate and acrylic acid according to US Pat. No. 2,607,711. According to US Pat. No. 2,985,554, silicon-containing polymers can also be used for this purpose.

However, these previously known separating materials and separating layers all have disadvantages. The release agent according to the present Invention overcomes all these difficulties In " truly surprising if it is within the scope of the invention Back cover is used.

The greatest disadvantage of the previously known release layers was the loss of release properties during aging. In a strip roll, for at a Abwiokelgesohwindigkeit of approximately 45.7 per minute, initially a force of perhaps 567 g / cm width was necessary to Abwiokeln, BKF had after prolonged storage a Abwiokelkraft 1417-2835 g / om or width about it can be applied. This

0098 :) 2/1508

Disadvantage occurs especially when the strip grooves are stored at higher temperatures, as they are for example

the wise near the roofs of department stores during / summer months, especially in the southern areas of the United States and in other areas with hot and humid climates to be expected.

The second major disadvantage of the prior art release liners is that they cause loss of adhesiveness or tackiness. These losses can occur immediately on contact between the separating layer and the adhesive or only after a long period of storage. Again, aging at elevated temperatures generally exacerbates this condition. A known adhesive, which had an initial adhesive strength of 992 g / cm width on stainless steel, showed an adhesive strength of only 709 g / cm after contact with the release layer. In some cases the adhesive strength can drop to 0 *

A third disadvantage of the previously known release layers shows up when a piece of an "adhesive tape" is attached to the rear surface of another piece of tape. This type of application arises in the packaging or when many strip sections are used to cover a surface. The failure of one end of the strip to adhere to another section of the road is called "flutter", while the top lobe of several strip sections when covering a surface is called "shingles".

For a successful application of this kind, the adhesive must adhere tenaciously to the separating layer. This, of course, runs counter to the need for easy unwinding of the adhesive tape from the roll. It is therefore a general view that release liners with good unwinding properties have the property of "peeling" and are only suitable for "shingling" to a limited extent or vice versa. Fortunately, this view is not generally correct. During the "shingling" process, the adhesive strip loosens

009832/160 6

e.g. by sliding relatively slowly at a low peeling angle while rolling off a roll goes on very quickly and at a 90 ° angle. the Bond strength is very much dependent on both the peeling angle and the peeling speed. For various adhesives and for different release liners the effects of peel angle and speed are very different. It has been found that, surprisingly, in the case of a large number of adhesives with the release layer according to the invention favorable conditions for an unexpectedly advantageous combination of "non-fluttering and good" shingling properties " are given with easy unrollability.

Another disadvantage of most of the previously known separating layers is that they are too specific in their effect are. While one works well against certain adhesives, it can work against another's adhesive Type to be largely worthless. The release agent used in the practice of the present invention has proven its usefulness against any of the many adhesives with which it has been tested.

A pressure sensitive adhesive tape has been found which is a thin, pliable and practically non-porous film or has a film as a carrier and overcomes all of these disadvantages of the prior art strips of this type.

the
In accordance with the invention, a separating layer is to be used which has the following unexpected combination of properties:

1. Regarding the power requirement, controlled rolling the strip roll, for example, neither too heavy nor too borrowed with improved evenness of unwinding.

2. Preservation of these properties over a long storage period under different temperature and humidity conditions.

J. Little tendency to decrease the tack of the pressure sensitive adhesive layer of the strip.

0 098 3 2/1506

BATH ORIGINAL

4. Good anti-platter and shingling properties th,

5. Many choices in the choice of the pressure sensitive Adhesive that can be used and still have all of the aforementioned properties of the Adhesive tape of the invention met.

Difficulty in achieving these goals of which at least some seem fundamental, cannot be emphasized enough. Pressure sensitive adhesives by their nature are necessarily semi-liquid in order to achieve adhesion with little or no pressure. They are mixtures of different substances and heterogeneous in their phase structure, especially on the surface is in contact with the separating layer. The production of the release agent film, which weighs perhaps only 0.0 ^ 4 g / m and alone Some molecules thick is obviously the most difficult one, because he has to keep his cinematic integrity and also his high level of planar orientation while facing the heterogeneous exposed to semi-liquid adhesive. It follows that the discovery of release backing layers of the type of the present invention not by scientific Predictions could be promoted. The implication that a low energy surface allows for easy separation what is needed was roughly the knowledge available. An adhesive strip with the desired release properties under a variety of conditions, such as economy and all the other features of a technical valuable product can be found empirically alone.

The invention relates to adhesive tape or release films with release liners and thin, flexible and substantially non-porous films as the carrier, which is characterized in that the separating layers of a copolymer of 50 - 8o wt -.% * Octadecylrnethacrylat or a mixture of alkyl methacrylates having at least 12 C atoms in the molecule, which mainly consists of ociadecyliiiethaorylate, and

00 3 832/1608 Ο · '*' ™ ^{m JAl} . _6th

-D-

Contains from 5o - 2o wt .- ^ acrylonitrile as a release agent.

The normal tacky, pressure-sensitive adhesive tapes according to the invention obtain a thin, flexible, practical one non-porous support in the form of a film or sheet, a layer of a normal, sticky and pressure-sensitive Adhesive on one side of the backing and a release liner on the other side of the backing. the The release layer contains copolymers of stearyl methacrylate and acrylonitrile as release agents in ratios between 5o parts by weight of stearyl methacrylate and 5o parts by weight of acrylonitrile to 80 parts by weight of stearyl methacrylate and 2o parts by weight. Parts of acrylonitrile lie. Preference is given to 50 parts by weight of stearyl methacrylate and 50 parts by weight of acrylonitrile up to 60 parts by weight of stearyl methacrylate and 40 parts by weight of acrylonitrile are used. If the copolymer is less than 20 parts by weight Contains acrylonitrile, the advantages sought with the invention cannot be realized. The one in this Application term used stearyl methacrylate means octadecyl methacrylate or higher alkyl methacrylates, which have at least 12 carbon atoms in the molecule and consist mainly of octadecyl methacrylate.

The separating layer can be applied to the carrier in the form of a solution

pressure

can be applied, for example by MCIQirolltechnik or by spatula technique in the case of heavy application or by any other technique that makes it possible Apply separating material in the desired thickness. After application, the solvents are removed from the layer evaporated by air drying or in an air circulation oven or on steam heated rollers or the like. The choice of the solid to solvent ratio depends largely on the method of application and the drying equipment available.

/ 1! .06

Aromatic hydrocarbons, ketones, esters and the like should be mentioned here as solvents which can be used. The solvents can also contain a proportion of aliphatic or naphthenic hydrocarbon solvents. In general, the solvent used, the level of pesticides and the method of application and drying do not have any significant influence on the basic properties of the adhesive tape produced, provided, however, that uniform coverage and drying are achieved for the release agent layer. Separating layers according to the invention which range from about 0.0;
siaid weigh.

P P

from about 0.0539 g / m to about 0.678 g / m in dry conditions

Other advantages of the invention over the prior art can be recognized from the following description, examples and claims together with the drawings.

Figure 1 is a schematic partial view of a self-adhesive tape according to an embodiment of the invention.

FIG. 2 is a likewise schematic view of a release film according to another embodiment of the invention.

Figure 5 is a schematic view of a fiber reinforced, pressure sensitive adhesive tape according to a somewhat different embodiment of the invention. The cut is laid across the tape to show the layers of threads that belong together.

In Fig. 1 of the drawings is a pressure sensitive adhesive tape of the one embodiment of the invention shown, which is a thin, flexible and practically non-porous Backing film 11 contains, as well as a pressure sensitive adhesive layer 12 on one side and a separating layer 15

009832/1506

the other side of the carrier 11. This strip is intended to be wound into a roll that the pressure-sensitive adhesive layer 12 faces down or inwards and in each turn the underside of the adhesive layer 12 remains in intimate contact with the outer surface of the separating layer 15. As described above, When the strip is unrolled, the adhesive layer separates easily from the separating layer without the use of extraordinary forces, wherein the adhesive does not adhere to and without any adhesion of the adhesive to the release liner remain. A conventional first intermediate layer, which is not shown in the drawing, can be between the carrier 11 and the adhesive layer 12 are arranged in order to better adhere the adhesive layer to the carrier to secure.

Another embodiment of this invention, as shown in Figure 2 is shown is a release film consisting of a flexible and practically non-porous carrier film 21, which is provided with the separating layers 22 according to the invention on both sides. This type of release film is called dfcft Designated cover film and is provided together with a self-adhesive, preferably a double-sided adhesive Adhesive tape, which has adhesive layers on both surfaces, to be used in such a way that the release liner the opposing layers of the adhesive strip will separate if the strip and the release liner fail to form one shown roll is wound. In another embodiment, also not shown, the separating film has a separating layer only on one side. This is applied to the adhesive layer of a one-sided adhesive Adhesive tape or an adhesive film applied for protective purposes. Therefore, this type of inventive Products generally as a release liner made from a thin, flexible and practically non-porous carrier film and a release layer according to the invention can be described on one side of the carrier. With such a release film

009832/150

the separating layer is supposed to have intimate contact with a normal, sticky layer of a pressure-sensitive layer for protective purposes Adhesive and still have an even and easy separation of the release film from the adhesive layer make it possible, regardless of whether this separating layer is on the carrier strip itself or on one or on both Pages of a separate release film is applied, which is then applied to the adhesive layer of an adhesive strip can be.

The embodiment according to Figure 3 includes a non-porous support film 31 ^an d an inventive release liner 32 on one side of the carrier 31 · The following layers are on the opposite side of the carrier 31 i the recorded order ⁿ arranged, for example, directly on the support a thin Pre-sizing 33, a first adhesive layer 3 ^, a layer of glass threads 35 which are embedded in a layer 36 impregnated with adhesive and a final layer of a pressure-sensitive adhesive 37 which is arranged over the layer 36 impregnated with adhesive. The separating layer 32 effects an easy and relatively uniform unwinding of sections of the adhesive strip wound into a roll without the adhesive being torn off. The threads 35 ensure a high tensile strength and tear resistance of the adhesive tape, which can be used as an insulating tape. In the following specific examples of possible embodiments of the invention are given, although the invention is not restricted to these examples,

example 1

49.8 g stearylraethaorylate, 60.9 g acrylonitrile and 1 g benzoyl peroxide v / earth blurred. In one with three necks Round-bottomed flask with a capacity of 500 cm, which is fitted with a Rülier, a ' A reflux condenser and a heating mantle are provided, 200 g of toluene are heated to reflux. From the Iloriomeregemlson were then at intervals of, 15 minutes each

BATH

about 10 ecm entered into the round-bottomed flask over a period of 3 hours, while the temperature in it drops from 112 ° C to 92 ° C. After the reaction mixture has been kept at a temperature of 92-94 ° C. for a further 2 hours, a solution of 33 g of benzoyl peroxide in 3.3 g of toluene is also added to it. The reaction mixture is then for a further 3 hours at a temperature of. 94 C to 98 C held. The total reaction time is 8 hours. The product obtained has a Peststoffgehalt of 25j6 wt -.% To. Are not ^ its share of substances, the constant during a 15 minutes heating to 204 C at a pressure of 10 mm Hg volatile, is 24.8 wt -.% And the amount of precipitate which, coming from the product having the same weight Methanol can be precipitated is 25% by weight . The intrinsic viscosity of the precipitated polymer is determined in ethyl methyl ketone - toluene 1; 4, is 0.04 and the acrylonitrile content of the precipitated polymer, as determined by nitrogen determination, is 47.1 %. The stearyl methacrylate content results from the difference to 52.9 # · The softening point is 99 ° C

This release agent solution is diluted with a toluene-Methyläthylketongemisch (volume ratio 3 J 1) to 2% Peststoffgehalt and 2 to a cellulose acetate film coated mm, so that a film having a dry weight of 0.17 g / m corresponds _n stands. The solvent is removed by au for 5 minutes Aufheize of the film to a temperature of 65 ⁰ C. On the ■. On the opposite side of the film, a pre-layer is applied, the dry weight of which is 0.68 g / m 2. After drying, an adhesive layer with the following composition in parts by weight of solids is applied over this preliminary layer;

- 11 -

BATH ORIGINAL

Colorless foam rubber · ■ Polyterpene resin F.P. 115 ° C Polyterpene resin F.P. 40 ° C butylated urea formaldehyde resin 2,5-di-tertiary-amylhydroehinone zinc dibutyldithiocarbarate p-toluenesulfonic acid

1 594057 100 Parts by weight 100 Parts by weight 10 Parts by weight 15th Parts by weight 2 Parts by weight 2 Parts by weight

2.95 parts by weight

After the adhesive has dried, the adhesive strip is cut and rolled up into rolls.

The unwinding adhesion is initially 189.2 g / cm width, after storage for 6 days at 49 ° C Kk £ a also 189.2 g / cm width and after 6 days of storage at. a temperature of 66 ⁰ C 446.4 g / cm width. Whenever the term "peel adhesion" is used in this specification in relation to an adhesive tape or release liner, it is meant the force in grams / centimeter width necessary to apply the strip or film at a speed of 47.7 meters / min by pulling its end in the radial direction from a roll of the strip or film which is wound on a freely rotatable core. The stick adhesion is initially 1.14 and after 6 days of storage at 49 ° C. 0.86 and after 6 days of storage at 66 ° C. 0.85. The quick adhesion, which is a very sensitive measure for the sinking, the stickiness, is determined as follows:

A piece of the adhesive tape is placed with the adhesive layer up on a horizontal surface and a hollow one Plastic ball rolled onto the adhesive tape at a certain angle. The vertical height from which the ball is started, is determined and the distance is measured that the ball rolls along the adhesive tape until it reaches the Calm comes. The value that results when the square root of the third is called rapid adhesion Power of the starting height multiplied by 2: * 54 in cm

- 12 -

009832/1506

the rait is 2.54 multiplied by the distance in inches that the ball is rolled, is divided. This ratio is a constant for a given adhesive tape. The ball used is made of nitrocellulose and has a diameter of 2.8l cm and a weight of 1.916 grams cleaned with petroleum ether and then dried. Of the Adhesive tape is for normal acetate film tape applications such as touching up paper, As a packaging closure and the like., excellently suited.

Example 2

100 g of toluene are brought to the boil in a 500 cm three-necked flask equipped with a stirrer, a reflux condenser and a heating mantle. In the boiling toluene, a mixture of 69.2 g of stearyl methacrylate, 4l, 5 g of acrylonitrile and 1.0 g of benzoyl peroxide in amounts of 10 ml at intervals of 15 minutes in a total of 3 hours is entered, the temperature of the The reaction mixture drops from 111.degree. C. to 91.degree. After the reaction mixture has been kept at a temperature of 91-97 ° C. for a further 2 hours, a further 0.33 g of benzoyl peroxide dissolved in 3 * 3 g of toluene are added, whereupon the reaction mixture is kept at a temperature of 97-98 ^{0 for a further 3 hours} C is held. The total reaction time is 8 hours. The product has a solids content of 45.6% by weight. The non-volatile residue remaining after 15 minutes of heating to 204 ° C. at a pressure of 10 mm Hg is 41.3% by weight. A precipitate can be obtained from 76.9 g of the product with 300 g of methanol, the amount of which is 44.8% by weight of the product. The acrylonitrile content of the product determined by nitrogen analysis is 37.5% by weight and the stearyl methacrylate content determined by differential calculation is 62.5% by weight. The intrinsic viscosity of the obtained with methanol at 30 C in a solvent consisting of toluene and methyl ethyl ketone in a volume ratio of 4: 1

- 13 009832/1506

average precipitation is 0.11. The melting point is 74 ° C.

The adhesive tape is produced as in example 1, only the release agent used in example 1 being replaced by the release agent obtained according to this example 2. The adhesive strength of the strip when unrolled is initially 200.9 g / cm width, after 6 days of storage at 49 ° C 457 * 6 g. The quick adhesion is initially ~ $, 8 after 6 days of storage at 49 ° C it is 4.2, and 3.6 after 6 Tqgen storage at 66 ⁰ C. The adhesive tape is very suitable for repairing and sealing.

Example 3

A release agent is prepared as follows: 18.0 kg of toluene are poured into a 75 l stainless steel vessel, which is sealed with a condenser and a stirrer, and brought to the boil. A mixture of 11 kg of stearyl methacrylate, 8.9 kg of acrylonitrile and 0.18 kg of azo- to isobutyronitrile is introduced into the reaction vessel over a period of about 3 hours at a rate of 0.11 kg / minute, while the temperature gradually increases from HO ⁰ C to 90 ⁰ C falls. The temperature is then increased again and ^{kept at 96-100 °} C. during the further reaction time. Two hours after the end of the addition of the monomer-catalyst mixture, a further 0.06 kg of azo-bis-isobutyronitrile dissolved in 0.8 kg of toluene are added. The heating of the reaction mixture is then continued for a further 3 hours. After a total reaction period of 8 hours, 36.3 kg of toluene are introduced into the reaction vessel in order to cool the product and adjust it to a suitable viscosity.

The Peststoffgehalt of the product is 25.2 wt -.%, Of mm after 15 minutes of heating at 204 ° C at a pressure of 10 Hg • remaining non-volatile residue is 24.2 wt -.%, And from 204 g of the product can precipitate out with 200 g of methanol, de »dry 24.5 Qew. ~ # des

BAD OBIGlNAl \

Product. The viscosity at 26 ° C. is 98 centipoise (determined according to Brookfield, with spindle No. 1 and βθ RPM). The softening point of precipitated with methanol low _T beat is 85 ⁰ C, its intrinsic viscosity, measured in A'thylmethylketon - toluene mixture in the volume ratio 1: at a temperature of 3O ⁰ C is 0.131, and its average molecular weight is 5 840. Its by nitrogen determination detected acrylonitrile content is 45.5 wt -.% and the calculated as the difference between content of stearyl methacrylate 54.5 wt .- ^. The release agent is diluted with a toluene-methyl-ethyl ketone mixture in a volume ratio of 3 '· 1 ^{to form} a 2-strength solution and applied to a 1.5 mm cellulose acetate film using a paint roller in such quantities that after drying, a layer with a dry weight of 0.12 g / m results. At the same time, an intermediate layer with a dry weight of 0.47 g / m 2 is applied to the opposite side of the film. After steam drying, an adhesive layer is applied to the intermediate layer, which has the following composition:

Colorless foam rubber, styrene-butadiene copolymer, aluminum hydrate

2,6-m-tolylene diisocyanate Phenol-formaldehyde resin modified with rosin, P.P.

2,5-di-tert-amyl-hydroquinone Dl-tert-butyl-p-cresol zinc dlbutyldithiocarbamate

150 ⁰ C

Polyterpene resin

O.

F.P. 115 C

87.5 parts by weight 12.5 parts by weight 50.0 parts by weight 2.2 parts by weight

10.0 parts by weight 2.0 parts by weight 2.0 parts by weight 2.5 parts by weight

80.0 parts by weight

This adhesive is prepared from a 28 weight - applied% solids containing solution in toluene with a dry weight of 25i ^ g / M.. Per cm of width, the adhesive

- 14 -

* »'R- fs fs

■ - 15 -

fabric layer then 25 parallel threads of 15O - I / O glass yarn

p arranged that 7 g / m dry weight of the aforementioned adhesive are covered with a further layer of 37 *, in the form of a 22 wt -.% solids containing solution to tiawird lacked.

A release paper protected with silicone is then applied Layer of the adhesive mentioned below, dissolved in toluene, applied to a dry weight of 50.85 g / m2:

Colorless rubber crepe / ⁺ loo parts by weight

Phenol modified

Polyterpene resin F.P. 115 ° C 40 Parts by weight Glycol ester one hydrogenated resin F.P. 8O ⁰ C 30th Parts by weight Polyterpene resin F.P. 40 ° C 2 Parts by weight oil soluble, hot hardening phenolic resin 5 Parts by weight Zinc resin LOi Parts by weight Zinc dibutyl dithiocarbamate 1 Parts by weight 2,5-di-n-amy-hydroquinone 2 Parts by weight Di-pentamethylene thioram tetrasulfite 1 Parts by weight

This layer is dried with removal of the solvent and ^{cured at a temperature of 176 °} C. for 45 seconds. The layer is then applied to the previously prepared carrier in order to form the last adhesive layer after the carrier paper provided with a silicone coating has been removed. The resulting adhesive tape, which corresponds to the representations as shown schematically in FIG. 3, is cut and wound up into rolls which can easily be unwound. This adhesive tape has the following properties: 368.3 g / cm wide adhesive strength on steel (PSTC-1 method). Rapid adhesion 53, unwinding adhesion bfti 45.72 m / minute .ναπ: '479.88 g / cm width, and an O ° adhesion on a box board of 3 hours. After aging

/ light creped natural rubber _ χβ _

BAD ORlGlNAt 009832/1506

159A057

- ιβ -

of the roll over a period of 6 days at a temperature of 66 ° C, the corresponding properties are 9 ^ 5 * 96 g / cm wide steel adhesion, quick adhesion 47, 81.4.7 g / cm wide unwinding adhesion and 4 hours 0 ° adhesive on one Crate board. The O ° -Liability on a box board is determined by applying a J, Q cm long and 1.27 cm wide portion of the adhesive tape to a box board, attaching a 200 g weight to the Klebstreifenende for generating a 0 -Scherkraft and measuring the time to to tear off at 21 ° C.

The adhesive tape produced according to the above has excellent properties for use in the Packaging and is useful for closing heavy cardboard boxes, for keeping refrigerator doors closed during the Transportes, for bundling floating objects such as wood, Pipes or automobile telephones and the like. The adhesive tape sticks excellent on its own support, so that the problem of detachment of strip ends when more than one layer around one Bundle is made is not given. Even so, the role can be unrolled with ease that it can without Difficulty to handle is.

Example 4

The release agent used here is the same as in Example J>. A solution of the release agent is prepared in such a way that an emulsion polymer of ethyl acrylate, styrene and methacrylic acid is first dissolved in methyl ethyl ketone and, after it has completely dissolved, a solution of the release agent in toluene containing 25% solids is added. The weight ratios are such that the solids ratio of the copolymer to the release agent is 1: 4 and the total solids content of the solution is 2 % . This solution is applied using a paint roller to a film of regenerated cellulose with 15 wt -% polyethylene glycol has been softened.. A coating forms with one

- 17 -

on η β 311 16 ο 6

BATH ORIGINAL

- ΪΓ -

Dry weight of about ο.17 gr / m ² . At the same time, an intermediate layer, also using a paint roller, is applied to the opposite side, which has a dry weight of about 0.68 g / m 2. These layers are then dried on steam-heated drying rollers. An adhesive layer of toluene solution is applied over the intermediate layer and dried, which has the following composition in parts by weight:

Synthetic polyisoprene, polyterpene resin P.P. 115 ° C Polyterpene resin P.P. 125 ° C di - t - butyl-p-cresol

loo

30th

4o

The dry weight of this adhesive layer is 23.7 m ² . The tape is then cut into smaller widths and wrapped around cores. The properties of this adhesive tape are as follows:

Adhesion on fast-unwinding steel adhesion

in gr / cm width in gr / cm width

without storage 457.56

after 6 days of storage

at 49 ⁰ C 546.84

at 66 ° C 468.72

8th, O 245 52 5, 6th 334, 8th 4, 5 557, 12th

Example 5:

The release agent according to Example 3 is diluted to a 2% pesticide-containing solution with a toluene - methyl ethyl ketone mixture (volume ratio 3: 1) and applied to a 2 mm thick film of cellulose acetate using a paint roller, so that a layer with a dry weight of about 0.17 gr / m ² is produced, which is dried over steam-heated rollers. The composition of the adhesive in weight points solid is:

eiπ-Ge

BATH ORIGINAL

-IH-

2 ethylhexyl acrylate vinyl acetate

polymeric 43.3 parts by weight

Polyvinyl ethyl ether. 25, ² I parts by weight

• 2,5-di ^p BERT Amy! Hydroquinone 1.3 parts by weight

The adhesive tape produced in this way is cut and wound on cores. The properties are the following:

Adhesion on unwinding adhesion steel

in g / cm width in g / cm width

without storage 301.32 78.12

after 7 days of storage

at 49 ° C 290.16 78.12

After 14 days of storage

at 49 ° C 279.0 89.28

after 6 months of storage

at room temperature 357.12 89.28

The adhesive tape is ideal for repairing, sealing and other applications in packaging.

Example 6

The carrier provided with the release layer of Example 5 is provided with an intermediate layer over which one Layer of adhesive according to the following composition

is raised, which has about 33.9 b / w dry weight.

Colorless rubber crepe
(light-colored creped natural rubber) 95 parts by weight

Polyisoprene rubber with high

cio content 112.5 parts by weight

Styrene-butadiene copolymer 100.8 parts by weight

Aluminum hydrate 111.0 parts by weight

Lanolin 3 * 2 parts by weight

Di-tert-butyl-p-cresol 7.2 parts by weight

2.5-Dl-tert-amy! .Hydroquinone ■ 4.0 parts by weight

BATH ORIGINAL

in

Polyterpene resin F.P. 115 ° C 138.2 parts by weight zinc resin 24, ο "

oil-soluble, hot-hardening

of phenolic resin 5o, 4 "

Phenol modified polyterpene resin F.P. 115 ° C 3o, o "

This adhesive is applied from a toluene solution and dried. The resulting adhesive tape is cut and wound on cores. The adhesive tape has the following properties:

Adhesion on fast-unwinding steel adhesion

in gr / cm width in gr / cm width

without storage 491, o4 o, l4 111.6o after 7 days of storage.

at 49 ° C 553.68 o.5o 178.56 after 14 days of storage.

at 49 ° C 446.040.33 178.56

The adhesive tape is very suitable as an electrical insulating and retaining tape.

Example 7;

The adhesive strip is produced according to Example 6, but with an adhesive layer of 37.29 g / m ² dry weight on a 1 mm polyester resin film, instead of the film made of acetate cellulose. The adhesive tape has the following properties:

Adhesion fast unwinding steel adhesion adhesion in gr / cm Br. In gr / cm Br.

without storage 542.52 o, 2o I45, o8 after 7 days of storage

at 49 ° C 5o2.2o o.25,312.48 after 14 days of storage

at 49 ° C 513.36 o, 33 323.64

0 0, 9 B 3 2/1 b 0 6

This adhesive tape is also ideally suited as an electrical insulating and retaining tape in areas to be used where the greater strength of the polyester film serving as a carrier is useful is.

There is a wide range of materials that can be used instead of thin, flexible, non-porous carrier films can be used according to the invention. In particular, materials such as cellulose acetate, regenerated cellulose, polyethylene, polypropylene, Vinyl films, polyesters such as polyethylene therphthalate and the like. The invention is merine are described in detail and it is also indicated in what way they are translated into practice can. In contrast to the known state of the art, it will be easy to identify innumerable variations, applications, Modifications and expansions of the principle on which the invention is based can be found without the area to leave the invention.

009832/1506

Claims (1)

- Wk- Claims Claim ii Adhesive strips or release films with release layers and with thin, flexible and practically non-porous films as a carrier, characterized in that the release layers are a copolymer of 5o - 80 wt .- ^ octadecyl methacrylate or a mixture of alkyl methacrylates with at least 12 carbon atoms in the molecule, the consists in the bulk of octadecyl methacrylate, and 5o - 2o wt -.% of acrylonitrile as a release agent. Claim ^g * Adhesive strips or release films according to claim 1, characterized in that the release layer has a dry weight of 0.0559 to 0.678 gr / m ² Igat. Blank page