DE1113777B - Method and device for the production of self-adhesive sheets or tapes with a pressure-sensitive adhesive layer on a carrier or a base - Google Patents

Description

GERMAN

PATENT OFFICE

B58683IVc / 22i

REGISTRATION DATE: JULY 20, 1960

NOTICE
THE REGISTRATION
AND ISSUE OF
EDITORIAL: SEPTEMBER 14, 1961

The invention relates to a method and an apparatus for producing self-adhesive Sheets or ribbons with a pressure sensitive adhesive on a backing or backing.

Pressure sensitive self-adhesive tapes or plasters are preferably used solvent-based adhesives produced. The adhesives are made from natural or synthetic rubber or rubber-like plastics together with adhesive resins, fillers, anti-aging agents, etc. using primarily flammable solvents and usually by means of a coating system applied to the web-shaped carrier. After applying the adhesive the adhesive strip produced in this way is usually evaporated through a drying tunnel and led to the recovery of the solvent and finally in the desired dimensions Rolls wrapped.

The known process for the production of self-adhesive tapes makes the use of expensive machines required, the installation of which also takes up a lot of space. Despite considerable expenditure for the systems provided for the recovery of solvents there are considerable solvent losses inevitable. The production speed of the self-adhesive tapes produced by the known method is essentially Extent determined by the comparatively low drying speed of the self-adhesive tapes.

It is also known that self-adhesive tapes can be produced by using solvent-free plasticized adhesives be rolled onto the carrier using a calender. For this procedure However, only supports made of resistant material can be used, as they are calendered z. B. creped papers or sensitive plastic films can be destroyed or damaged. For this process, too, comparatively expensive machines are required.

Finally, it is known to produce melts from suitable plastics and to store them in hot, to be applied to the carrier in a low-viscosity state by means of conventional coating devices. For this Only a few plastics, such as polyvinyl ether, come in various degrees of polymerisation as raw materials in question.

The invention aims to provide a method and an apparatus for the production of self-adhesive sheets or tapes, in which the disadvantages of the known working methods are avoided and a great variety of raw procedures and device

for the production of self-adhesive sheets or tapes with a pressure-sensitive Adhesive layer on a carrier

or a pad

Applicant:

P. Beiersdorf & Co. A. G., Hamburg 20, Unnastr. 48

Dipl.-Chem. Dr. Wilhelm Sahler,

Aumühle near Hamburg has been named as the inventor

substances for the self-adhesive can be used without the use of solvents.

The invention is based on the knowledge that self-adhesive sheets and self-adhesive tapes or plasters produced in a simple and advantageous manner using solvent-free adhesives can be prepared in a heated screw press and from this in the form of a melted Mass are applied to the carrier.

According to the invention, a mixture of the components of the self-adhesive composition is produced, transferred the mixture in grain or granulate form, the granular material leads a heated screw press and from this the molten mass is continuously sprayed through a slot nozzle the carrier as it is moved past the nozzle.

For this purpose, skins made of natural rubber, synthetic rubber, or high molecular weight can be used on a mixing roller Polyisobutylene, polyvinyl ether or mixtures of these substances with adhesive properties

109 688/205

3 4

averaging material, such as resins, e.g. rosin, in order to provide the the heated screw polyacrylic acid ester and. If necessary, to facilitate mixed polypress granular goods to be fed in, merizates of acrylic acid esters and vinyl ethers, aluminum and a sticking or caking of the goods kydharze, polyterpene resins, and optionally to prevent plasticizer, this can be prevented after granulating, such as hard paraffin or paraffin oil, or never- 5 process or after the mixing process obtained kördermolecular polyisobutylene types or polyvinyl nige Gut with a surface to protect against isobutyl ether and, if desired, fillers, such as baking, with the same zinc oxide, and other additives, such as antioxy- timely a precise dosage of the components of the dationsmittel, processed into an intimate mixture of granular goods and a homogeneous mixture of which are then cut into ribbons and z. B. is guaranteed on io components,
a belt granulator in grain or granulate form in order to stick or stick together. To prevent the elastomeric materials, the particles of the granular and / or the adhesive properties imparting material can be wetted with solutions or dispersions of film image materials, polymers of the same type, such as non-adhesive synthetic or natural resins, but with different degrees of polymerization be dried with agitation, so will. that a non-sticky film like a wire

According to a modified embodiment of the yaw results. The granular material can be you can spray or bathe the components of the self with aqueous polyvinyl alcohol adhesives in grain or granulate form or powder and polyacrylic acid solutions, aqueous plastic form with each other intimately to form a granular mass 20 dispersions or solutions of suitable resins mix and this mixture of the heated screw in solvents, which the grapress to be coated respectively. nulate not attack or only slightly attack, be provided

The method according to the invention has the advantages. All substances are suitable as film-forming agents

part that for the production of the self-adhesive, all the, although they are sticking together or

Raw materials commonly used in engineering to prevent the particles from sticking onto the

in particular also natural and synthetic rubber and the self-adhesive mass to be produced no disadvantageous

Difficult-to-melt plastics are used to exert influence, but whenever possible

can. The method according to the invention even improves its properties. That with the

net is that the production speed solutions or dispersions provided granular material

Compared to the known processes, the excess liquid is separated

borrowed increased and the space requirement for the whole dried, whereby by whirling up in

system is considerably reduced, so that the capacity of the heated air or tumbling a possible collapse

In a given space, the system prevents sticking during the drying process

is increased significantly. can be. An increased separation effect is too

A significant advantage of the method according to FIG. 35 can be achieved if towards the end of the drying pre-invention Compared to the known processes, powdery substances such as zinc oxide are used of plastic melt is to be blown. A treatment, e.g. B. circulation that the process is carried out completely continuously with powdery substances such as zinc oxide or can be. colloidal silica, if appropriate, also performs

Since no solvents are used, 40 without the use of solutions or dispersions

a fire or explosion hazard is excluded, from film formers to usable, not combined

there are no recovery losses and the sticky granular material.

Cost of a recovery system. The drawing shows a device for executing

According to this embodiment of the invention, the method according to the invention can be exemplified the carrier material is shown by a guide device. With 1 is generally a heated one tung are worn, the z. B. a pair of co-screw press or an extruder referred to, the has menarbeitenden rollers, of which at least a hopper 2, an extruder body 3 and at least one roller is driven. The temperature has a slot nozzle 4, which is preferably one or both rollers can also be heated by heat. The extruder is for step transfer media set in the desired way 50 wise heating set up and has when presented, Embodiment provided five heating zones. Under-

In this mode of operation, the output of the slot nozzle 4 can also be sensed

Lighter carriers, such as thin plastic films, a perfect guide device for the carrier material 5

can be coated freely because the temperature of the see, which has a pair of rollers 6 ', 6 "of which

Rolls is adjustable and this optionally ge 55 at least one roller, z. B. the roller 6 ', driven

can be cooled, while in the known ben is.

Calender process the use of heated. The carrier material 5 is taken from a supply roll 7

Rollers for plasticizing the adhesive required- pulled off and over a deflection roller 8 over the

is borrowed. Roller 6 'out.

When using rollers according to method 60, the molten material prepared in the extruder

According to the invention, the contact pressure can be low. The adhesive mass runs in the form of a thin, flowable adhesive

be held because the adhesive mass through the loading film from the gap of the slot nozzle 4 on the

handling in the heated screw press carrier material already fed from the roller 6 ',

into a liquid, plastic and easily spreadable

State has been transferred. In the known 65 arranged slot nozzle 4 directed so that the film

This state must first be applied to the gap of the calendering process from molten adhesive

the presence of the underlay material by means of a considerable two rotating in opposite directions with a pull-in effect

Pressure and heat are generated. Rolls 6 ', 6 "is directed.

5 6

The drawing) introduced in direct contact with the adhesive, the cylinder and nozzle '

Coming counter roller 6 ″ can one the adhesive heating in the direction of the outflow gap on the following

mass-repellent coating made of z. B. Polytetrafluor (increasing) temperatures were set: ethylene, polytrifluoromonochlorethylene or silicone

have rubber. 5 ^zone * ^{40 C}

The two rollers 6 ', 6 "can pass through water zone 2 at 80 ° C

or another heat transfer medium cooled zone 3 120 ° C

will. If necessary, however, a heating zone 4 can also be 190 ° C

tion take place through the heat transfer medium. Zone 5 250 ° C

The application thickness of the adhesive mass can be determined by the io

Screw speed of the extruder, the contact pressure that emerges from the slot of the slot die

the rollers and the speed of rotation of the whale liquid film was applied to a cellulose fabric

zen can be adjusted as required. gen, which is pulled from a supply roll and through.

The components for the self-adhesive mass are a guide device with two working together or in a mixture on a rolling mill to 15-tend, counter-rotating rollers, rolled out and cut into strips of about 5 mm thickness by regulating the screw to close by turning it into strips of 300 mm width - number of the extruder and the contact pressure of the beds. In this form, the material is applied to the infeed layering rollers with an application thickness of approximately the slit of a "band granulator", construction 120 g / m ² . That be-CONDUX, fed in this way. The tissue layered on an axis parallel 20 had a firmly adhering superordinate rotating circular knife cut the train of adhesive with self-adhesive property tapes first into narrow strips of about 5 mm and, if it was to a dry, grease-free width, then by a Cross-cutting surface was glued on, can be chopped up by this residue knife, so that an approximately dice-free peel off again, mige granules with an edge length of 5 mm
stands. _R. -19

The cut material can be poured into a container

be dropped that contains a solution or dispersion 20 parts of a partially vulcanized chewing

sion of an anti-sticking agent contains. Tschuks,

Thereafter, it is separated by sieving of the excess 30 ₂ 0 parts of polyisobutylene with a mole-liquid and then with a moist weight of from about 150,000 ( "Oppaten film surrounded material by vortexing in _ηο ^ g - ^ q jjaSF) a heated air stream or by sucking _{OQ T.} , ", ". ,, '. . _Λ ,, warm air by the material applied to the surface of a ^{29 T} f ^e polyisobutylene with an emem Mole drying drum. 35 kukr weight of about 15,000 (»Oppa-

The invention is described below with reference to Bei- “ _n ° ™ * ° ^ ' . ^'. ,. «, ....

play explained in more detail: ^{j0 parts} hydrogenated rosin (Staybilite

Resin),

1 part anti-aging agent (a-naphthyl example _{40 aminaldehyde condensation product)}

It became a homogeneous mixture

. "_., _,. ,,. . ,,, were according to the work described in Example 1

40 parts of polyisobutylene having a molecular _{wdse gemisdlt granulated} \ _mt made flowable and

Weight of about 150,000 (»Oppa- processed. Instead of the cellulose fabric, a

nol «B 150 BASh), _4g creped, tempered by plastic impregnation

30 parts of polyisobutylene are used with a mole paper. A pressure sensitive one was obtained

Weight of about 15,000 (»Oppa adhesive tape, in which the self-adhesive compound is a good

nol «B 15 BASF), had adhesion to the crepe paper backing.

15 parts rosin,

14 parts of cyclohexanone resin (synthetic resin 5 ° Example 3

AW 2 BASF)

, _φ .,!,. ,. ..., 20 parts natural rubber (air dry),

1 part anti-aging agent. _Λ,,

(2,5-di-terL-amylhydroquinone) (»Santo- ^{20 parts} crepe rubber,

var ^ 4 «) 20 parts of polyisobutylene with a MoIe-

55 gross weight of around 15,000 (»Oppa-

_W i it. * ii a ■ nol «B15, BASF),

Manufactured on a rolling mill and converted into an approx. _{25 Tdl phthalic acid ester of Abitol}

5 mm thick skin rolled out. The fur became lim on m Banrr ii

cut about 30 cm wide. The so- _ ^, *? ^ '\ _ _. ,. .,

The last ribbons were pulled into a "ribbon granulator" 60 ⁵ parts paraffin oil (Paraffinum liquidum

leads and transformed into a granulate, which in ^{5 En} ^ ^{er at 50 C)} '

a 5% aqueous polyvinyl alcohol solution to 10 parts of zinc oxide

was caught. After draining the liquid

the granular material was mixed with continuous stirring as described in Example 1, Belung dried in a heated air stream. 65 granulated, made pourable and over the with The granular material was then fed into the feed slot-fitted extruder onto the upper hopper a surface of a stretched hard polyvinyl chloride film provided with a slot nozzle Screw press or an extruder (cf.

A self-adhesive tape with good adhesive properties was obtained.

Example 4

The granules obtained according to Example 3 were used instead of treatment with aqueous polyvinyl alcohol solution with an aqueous dispersion of a carboxyl group-containing copolymer based on vinyl chloride (»Lutofan« 200 D) impregnated and dried. The granules had after this treatment no tendency to stick together, was free-flowing and was easy to process on the extruder. A synthetic leather (cotton fabric coated with polyvinyl chloride on one side), which is made with the heated extruder ejected adhesive was coated in the manner described in Example 1, provided a pressure-sensitive self-adhesive tape with good adhesive properties.

Example 5 _ao

Sheets made of partially vulcanized rubber (Perfect Sheets) were granulated by themselves and treated with a dispersion of a copolymer containing carboxyl groups based on vinyl chloride ("Lutofan" -200-D-Dispersion) made non-adhesive. After drying, the granules were with coarsely ground rosin and aldol-a-naphthylamine mixed.

Composition: “ ₀

45 parts partially vulcanized rubber,
44 parts rosin,
1 part aldol-a-naphthylamine (anti-aging agent AP).

35

The mixture was filled into the hopper of an extruder heated as in Example 1, and it 10 parts of paraffin oil (Paraffinum liquidum 5 ° Engler at 50 ° C) were used during processing a short tube ending above the screw, adapted to the processing speed, is metered in. A coated with this mass, with an emulsion of a synthetic rubber based on butadiene-acrylonitrile ("Perbunan" emulsion) pre-coated hydrate cellulose film showed good, self-adhesive Properties.

Example 6

A mixture of 20 parts of natural rubber (air-dry),
20 parts crepe rubber,
20 parts of polyisobutylene with a molecular weight of about 15,000 ("Oppanol" B 15, BASF),
25 parts of phthalic acid ester of the dihydro

abietyl alcohol,
10 parts zinc oxide,
5 parts hard paraffin

produced and converted into a free-flowing granulate according to the procedure according to Example 1, the one for the heated extruder with a slot die on a carrier made of cellulose fabric and hydrate cellulose was applied.

Self-adhesive tapes with very good adhesive properties were obtained.

Claims (12)

PATENT CLAIMS: 55 1. A process for the production of self-adhesive sheets or tapes with a pressure-sensitive adhesive layer on a carrier or a base, characterized in that a mixture of the components of the self-adhesive composition is produced, the mixture is converted into granular or granular form, and the granular material is fed to a heated screw press and from this the molten mass is continuously sprayed through a slot nozzle onto the carrier while it is moved past the nozzle. 2. Modification of the method according to claim 1, characterized in that the Components of the self-adhesive in grain or granule form or powder form intimately with one another mixes to a granular mass and the mixture obtained is fed to the heated screw press. 3. The method according to claim 1 or 2, characterized in that after the granulating process or the mixing process obtained granular material with a surface against caking protective layer. 4. The method according to claim 3, characterized in that the particles of the granular Good things with solutions or dispersions of film images, such as non-adhesive synthetic or natural resins, wetted and dries with movement. 5. The method according to claim 3, characterized in that the particles of the granular Good things are circulated with a powdery material such as zinc oxide or colloidal silica. 6. The method according to claim 3 or 4, characterized in that the particles of the granular Good can be treated with aqueous polyvinyl alcohol solutions or polyacrylate solutions. 7. The method according to any one of claims 1 to 6, characterized in that the components the self-adhesive made of elastomeric material, such as natural rubber, synthetic rubber, polyisobutylene, Polyvinyl ether or mixtures of these substances, and material that provides adhesive properties, such as rosin, polyacrylic acid esters and, if appropriate, copolymers of acrylic acid esters and vinyl ethers, alkyd resins, polyterpene resins, and optionally plasticizers, such as hard paraffin or paraffin oil, and, if desired, additives such as antioxidants, Zinc oxide or the like., Exist. 8. The method according to claim ?, characterized in that the elastomeric materials and / or the adhesive property-imparting materials made from different polymers Degree of polymerization exist. 9. Device for carrying out the method according to one of claims 1 to 8, characterized by a mixing device for the components of the self-adhesive, one expedient arranged below the extruder, which is set up for step-by-step heating, and one to the Outlet opening of the extruder connected heated slot die and a guide device for flexible sheet or sheet material. 10. The device according to claim 9, characterized in that the guide device for the backing material is a pair of working rolls, of which at least a roller is driven. 11. The device according to claim 10, characterized in that the temperature of one or both rollers is adjustable by heat transfer means. 10 12. The device according spoke 10, characterized in that the with the self-adhesive coming into contact roller with a coating of z. B. Polytetrafluoroethylene, Polytrifluoromonochlorethylene or silicone rubber is provided. 1 sheet of drawings