DK173619B1 - Multi-layer, flexible self-adhesive transfer tape to cover text or drawing by manual application and method of making it - Google Patents

Description

in DK 173619 B1

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a multilayer, flexible self-adhesive transfer tape for covering text or drawing by manual application, comprising an auxiliary support member and a contact adhesive layer in between, which is provided with a binder-containing transfer layer that adheres more strongly to the contact adhesive layer than to the auxiliary base layer.

Various possibilities are known for the use of pigmented, liquid systems to cover erroneous writing. Thus, it is known in the office field for the correction of typefaces and the like to use white pigmented dispersions containing a slightly volatile organic solvent and applied with a brush. However, the evaporation of the slightly volatile organic solvent is detrimental to the environment. Furthermore, it takes a relatively long time for the volatile solvent to evaporate and an overwrite can be made. When applying the correction dispersion by means of a brush, a uniform coat of cover is not usually obtained.

A better solution is disclosed in DE Publication No. 26 26 891, which discloses a multilayer, flexible transfer sheet formed by an auxiliary layer coated adhesive body, a polyvinyl alcohol bonded transfer layer, and a thin adhesive layer. The transfer layer additionally contains titanium white as pigment. After removing the auxiliary body, the transfer layer serves as the correction layer for erroneous characters. This German publication disclosure does not disclose the use of such a hand operated roller holder, which will be described in greater detail later in the present invention, and experiments have shown that with such a hand operated roller holder, the desired sharp tearing of the proofing layer cannot be achieved by this known transfer sheets.

2 DK 173619 B1 GB-A-1 036 743 discloses a multilayer transfer sheet which has a color-emitting layer between a base layer with a plastic binder and a cover layer with a plastic and / or wax binder. The color-emitting layer may comprise ethyl cellulose. Such a transfer sheet is used in connection with typing, where it is stated that even a slight touch will cause the color-emitting layer to be transferred to the paper.

The object of the present invention is to further design the transfer belt initially described in such a way that the binder-containing transfer layer can be transferred cleanly and sharply to the sites to be covered and the transfer belt can be used in a hand operated roller holder for a quick and uniform transfer to the substrate in a simple manner.

20

This task is solved according to the invention in that the binder-containing transfer layer contains a tear-off aid in the form of a soluble cellulose derivative.

The auxiliary carrier body of the flexible conveyor belt preferably comprises such a plastic film, e.g. of polyethylene terephthalate, polypropylene, polyethylene, polyvinyl chloride, and polycarbonate, used as supporting bodies used in typewriter ribbon. Also, silicone-coated paper is suitable as an auxiliary support body. The silicone coating reduces the adhesive tension between the binder-containing transfer layer and the auxiliary support body. Instead of the silicone coating, various anti-sticking agents, e.g. polytetrafluoroethylene.

DK 173619 B1 3

Preferably, the auxiliary support body has a thickness of approx. 10-60 μπι, preferably 15-55 μκι, the cover layer thickness of approx.

5-40 µm, preferably approx. 15-25 pm, and the self-adhesive 5 adhesive layer a thickness of approx. 1-8 µπ \, preferably approx.

2-5 μπι. In order to optimize the transfer belt according to the invention, it is convenient to choose a thickness ratio between the self-adhesive adhesive layer and the transfer layer of between approx. 1: 4 and approx. 1:12, preferably between ca. 1: 8 and approx. 1:10.

The adhesive layer may comprise conventional commercially available contact adhesives. These are materials which form elastic, durable, self-adhesive masses, which have high adhesion forces, and which, at room temperature and already under low pressure, immediately adhere to different surfaces. They are preferably applied in aqueous solution to the transfer layer already applied to the auxiliary body, in that way the already formed binder-containing transfer layer is not redissolved. Among contact adhesives of this kind are particularly advantageous ones which are based on acrylate. The starting materials may be viscous solutions or dispersions based on rubber, polyacrylates, polyvinyl ethers or polyvinylisobutylene. In particular, materials based on polyacrylates are preferred. Suitable trading products are Ucecryl 913R and Ucecryl PC80 (sold by the company UCB, Ammelicht, Belgium) and plastic dispersion VP 859/6 (sold by Freihoff). The contact adhesive to be applied and usually present in an aqueous medium preferably contains wetting agents or surfactants (sold under the trade name Byk W). Said solutions or dispersions of the contact adhesive to form the contact adhesive are preferably applied in an amount of about 10%. 1-5 g / n, and particularly preferred in an amount of approx. 2-4 g / no on the transfer layer.

For forming the binder-containing transfer layer, thermoplastic or thermoelastic polymers are preferably used in solution or in the form of a dispersion.

According to the invention, the following substances are advantageously used for solving the stated task: 10 I. polyurethanes having a molecular weight of 15,000 50,000, e.g. Permuthan U 4924 from Stahl-Chemie or Dosmolac 2100 from Bayer AG, 15 II. linear saturated polyesters having a molecular weight of 20,000 - 30,000, e.g. Vitel PE 307 from the company

Goodyear Tire & Rubber, III. styrene-isoprene-styrene copolymers, e.g. Coriflex TR 1107 from Shell-Chemie, IV. acrylates and methacrylates, e.g. Pexigum 7 H from Roehm GmbH, 25 V. diphenylcarboxylic acid modified polyamides, e.g. Scope 30 from Rhone-Poulenc or Eme-rez 1533 from Emery Chemicals, VI. polymeric dispersions based on vinyl propianate, e.g. propiophane 6D from the company BASF, VII. carboxymethyl group-containing water-soluble poly-methacrylate, e.g. Rohagit SD15 from the company Roehm GmbH.

DK 173619 B1 5

In order to obtain an optimum embodiment of the invention, the choice of the binder for forming the transfer layer must also take into account the nature of the plasticizer used. A plasticizer should be used which, when applying the transfer layer to the surface to be corrected or covered, does not penetrate the usually thin contact adhesive layer and comes into contact with the site to be corrected or with the dyes present. settle at this site and dissolve these with the resulting unfortunate discoloration of the transfer layer. It has been found that standard plasticizers such as silicone, castor oil and mineral oil are suitable. Other plasticizers, such as e.g. phthalates and olein alcohol, which are preferably used in other applications, are not well suited. In order to counteract the said adverse effect of the plasticizer in boundary cases, the binder-containing transfer layer may be added a so-called "binder lacquer" which precipitates any migrating dye or makes it insoluble, so that it does not migrate into the applied transfer layer and colors. this. Suitable binder varnishes are tanine and tanine derivatives. Usually, it is possible to use adhesive varnishes of the same type known to be used in ink and ink. The adhesive varnish is preferably used in an amount of approx. 0.5-5% by weight and especially about 1.5-3.5% by weight in the binder-containing transfer layer. Particularly preferred is an amount of approx. 2-2.5% by weight.

30

In the preparation of the transfer belt according to the invention, the selected binder is used to form the transfer layer preferably in the form of a solution or is used if there is a polymer dispersion such as a dispersion. The choice of the solvent depends on the nature of the binder used. Preferably, low to medium boiling organic solvents of the group of alcohols such as ethanol sapropanol and butanol, ketones such as acetone and methyl ethyl ketones, esters such as methyl and ethyl acetate, aromatic hydrocarbons such as toluene, aliphatic hydrocarbons such as benzenes are used. with boiling point in the range of 70-140 ° C, either alone or in admixture, as well as in water or in admixture with low boiling water-soluble organic solvents. The concentration of the binder in the solution and dispersion, respectively, is not essential to the invention. As a rough guideline, it can be stated that it can be approx. 3-15% by weight and preferably approx. 4-10% by weight. To form the transfer layer, this solution or dispersion is preferably applied in an amount of 15-25 g / πτ and especially preferably in an amount of 18-22 g / m 2 2 on the auxiliary support body.

In the context of the present invention, the term "colorant" is to be understood in the broadest sense as a common term for all color-emitting substances, so that it also includes dyes and pigments, the latter of which may also have the character of fillers.

2

Dyes are those dyes which are soluble in water, organic solvents or binders as opposed to insoluble pigments. The coloration may be direct, but may also appear by fluorescence. The latter occurs e.g. in the case of fluorescent luminous colors. If the transfer tape according to the invention is used to correct printed characters, pictorial illustrations or the like, the binder-containing transfer layers especially contain white pigments, such as e.g. titanium white, precipitated chalk, clay soil or colloidal silicic acids. In order for the transfer layer to be colored, the dye used is inorganic pigments such as chromium yellow, ocher, iron oxide red, cobalt blue, ultramarine blue, berliner blue, or organic pigments such as alkali blue, phthalocyanines, azo dye pesticides, antioxidant substances, carbon black and iron oxide black. Examples of fluorescent dyes are Blaze Orange T 15 from Dayglo, Ma-xilon brilliant flavin 10 GFF from Ciba Geigy, Pyra-nin from Bayer AG and Basonyl red 540 from 10 BASF.

The control of the optimum covering function of the transfer belt according to the invention and especially of the binder-containing transfer layer can be effected by means of the pigment content. The optimum pigment content depends on various factors such as the nature of the binder selected, the pigment in question and the additives added. A specific critical value or range cannot be specified. As a rough guideline, for the binder / pigment 20 ratio, a weight ratio of about approx. 1: 1 and approx. 1:12, preferably between about. 1: 3 and approx. 1: 8 and quite preferably between ca. 1: 4 and approx. 1: 7th

An important component of the binder-containing transfer layer of the transfer belt according to the invention is a "tear-off aid". Only by using such a tear-off aid is it ensured that upon application of the transfer layer to a substrate, a clean tear is obtained under tensile stress conditions. Surprisingly, it has been found that one relatively limited group of compounds, namely soluble cellulose derivatives, has the desired properties as a tear-off aid according to the invention. Particularly preferred cellulose derivatives are the cellulose soluble ether such as methyl, ethyl, hydroxyethyl, ethyl hydroxyethyl and carboxymethyl celluloses, cellulose esters such as cellulose acetate, acetate, acetobutyrates and organic solvents and / or water soluble cellulose esters. propionates. However, various other soluble cellulose derivatives are also suitable and give the desired effect.

It appears that the cellulose base structure of the soluble cellulose derivative is important, while the introduced groups such as the ethyl group etc. cause the resulting derivative to be soluble in the selected solvent.

The amount of the tear aid introduced into the transfer layer is not critical as it depends on the nature of the binder, the nature of the pigment and the nature of the other introduced additives. Preferably, an amount of approx.

0.5 to 5% by weight, and particularly preferably an amount of approx.

1.5-3.5% by weight. Quite particularly preferred is an amount of approx. 2.0-2.5% by weight. These amounts are calculated on the basis of the dry matter. Thus, the amount ratio of the tear aid to the binder can be used as the basis for the preparation of the transfer layer.

As a rough guideline, a ratio between the tear aid and the binder of between approx. 1: 2 and approx. 1:20 and preferably between about. 1: 4 and approx. 1:10.

25

To control the application as well as the properties of the transfer layer applied to the substrate, additional additives may be added. In particular, these may be means of improving the capability, including in particular aluminosilicate, toning agents such as e.g. carbon black, or the aforementioned binder varnishes, especially for basic dyes, e.g. in the form of gallic acid derivatives, such as printan from the company Ciba Geigy.

DK 173619 B1 9

The aforementioned materials for the various layers of the conveyor belt according to the invention are usually sufficient to meet the basic requirement that the adhesive stress (defined by the adhesion work corresponding to Dupre's equation, cf. KK Wolf '' Physics und Chemie der Grenzflåchen ', Springer Verlag 1957 , page 164) between the self-adhesive contact adhesive layer and the transfer layer must be greater than the adhesive tension between the auxiliary carrier and the transfer layer. In this case, if this condition 10 is not met, a suitable anti-adhesive layer must be applied to the auxiliary carrier body to meet this basic requirement. In such cases, the additional condition is usually fulfilled that the transfer layer formed on the substrate is non-adhesive to other materials, especially paper that comes into contact with it, thus the following adhesive stress conditions can lead to successful use of the transfer belt according to the invention. , the symbol "S" denotes the adhesive stress ratio of the various materials, e.g. Sj_ paper / contact adhesive layer, S2 transfer layer / contact adhesive layer, S3 transfer layer / auxiliary body, S4 transfer layer / paper and S5 auxiliary adhesive layer / auxiliary body and the following conditions are met: S ^ larger than S3, S2 larger than S3, S5 much smaller than S £, and S5 less than S3. Furthermore, the free surface 25 of transfer layer applied to a substrate, preferably paper, should have no adhesive outward, i.e. that S 4 is zero or approaches zero. In other words, the applied transfer layer should not be sticky when touching a hand or with paper.

30

The advantageous method of preparing the transfer belt according to the invention is characterized in that a plastic solution containing a tear-off aid in the form of a soluble cellulose derivative is applied to a flexible auxiliary body by conventional application methods, by evaporating the solvent, then on the formed transfer layer by conventional application methods, an aqueous dispersion containing a contact adhesive is applied and the water is then evaporated.

Using the transfer belt according to the invention, it is advantageous to use conventional commercially available applicators enabling the transfer layer provided with the self-adhesive contact adhesive to be coiled while simultaneously pulling the auxiliary body. This enables particularly easy handling of the transfer belt according to the invention. The applicators 15 may be the usual hand-held hand tools. A particularly suitable apparatus of this kind is a so-called "" hand-rolling clay tool, "in which is placed in the interior of a housing having a hand-advantageous shape a supply coil with the transfer belt, and the transfer belt is passed A suitable drive between the two coils in the housing ensures that the conveyor belt is kept sufficiently tight at all times using a conveyor belt which protrudes from the housing extending from the housing and from which it is retracted. his hand and, by means of the applicator foot, presses the outwardly extending, tear-off layer of the tape down towards its substrate to which it is to be transferred (for example, a printed sheet of paper for effecting corrections). against the substrate, the apparatus is moved relative thereto, thereby transferring, for example, a covering or fluorescent layer to the substrate, e.g. round the flexible auxiliary body is unwound from the supply coil and coiled on the reel coil.

DK 173619 B1 11

The conveyor belt according to the invention is especially suitable for use as a correction agent in offices, in schools and homes by covering printed typos, erroneous markings, drawings and re-writing. Another application of the transfer band may be the color labeling of surfaces, documents and / or characters, in which case the transfer band comprises a transfer layer containing a colored pigment. A further use is the highlighting of text sites, symbols or illustrations. For this purpose, the transfer layer is preferably transparent and stained with a luminous fluorescent dye. In all the aforementioned application examples, it is particularly advantageous for the application to be "dry", ie.

15 that there is no smearing of liquid coating layers and evaporation of unacceptable solvents, and that re-writing can be done immediately. The transfer belt according to the invention thus permits an easy, fast and uniform transmission of e.g. cover layers which preferably contain dyes for substrates. If the transfer layer of the transfer belt according to the invention is transparent, i.e. that it is e.g. does not contain covering pigments, it can be used exclusively as a cover layer without color effect and thus to preserve and protect 25 characters otherwise sensitive to the influence of air and the like.

In the following, the invention is further explained by way of examples.

30

Example 1.

First, the following dispersion is prepared to form the dye-containing transfer layer: DK 173619 B1 12 In solvent-soluble polyurethane 19.0 parts by weight (Permubutan U 4924) (25¾ in isopropyl alcohol / toluene, 1: 1 ratio)

Isopropanol 10.0

Toluene 35.0

Adhesive lacquer (Printan G) 1.0

Ethyl cellulose N7 (tear aid 1.0 part)

Titanium Dioxide (Kronos RN34) 29.0

Aluminum silicate P820 (means for improving the coating performance 5.0)

Carbon black (Printex 140V) (tint average 0.01 deD

100.01 parts by weight

The foregoing cover was applied in an amount of 18 g / m2 to a silicone treated paper carrier by means of a doctor blade. Then, the solvent was evaporated by means of 5 hot air at a temperature of 100 ° C. Then, by means of a blade, one of the following constituents comprising aqueous dispersion was applied to the surface of the colorant-containing cover layer:

Acrylate-based, self-adhesive contact adhesive 66.9 parts by weight of agent (plastic dispersion VP 859/6 from Freihoff) (acrylic acid ester based copolymer

Water 3 3, 0 - "-

Wetting agent or surfactant 0.1 substance (Byk W) ....................................... ...........................................

100.01 parts by weight DK 173619 B1 13

The self-adhesive contact adhesive was applied at a thickness of 2 g / m2 using a blade. The water fraction was then evaporated at approx. 100 ° C using hot air.

5

The obtained transfer tape was particularly suitable for covering printed characters on paper. It enabled a quick uniform application of a tire strip that could be immediately re-described. The application was done by means of a sperm commonly used hand rolling tool.

Example 2.

Example 1 was changed by using the following composition to form the dye-containing transfer layer:

Polyurethane (Desmolac 2100 from the company 5.0 parts by weight)

Bayer AG)

Methylethyl ketone 30.0

Toluene 28.6

Maxilon Brilliant Flavin 10 GFF (BASF) 1.0

Basonyl Red 540 (BASF) 0.4 - "-

Titanium Dioxide (Kronos RN 34) 29.0

Aluminum silicate P 820 (Degussa) „„ .S'0

Ethyl cellulose N7 (Hercules) 1.0

The transfer layer of the transfer band thus obtained had a good coverage and was colored (orange) and was not fluorescent.

Example 3

Example 1 was changed by using the following composition to form the dye-containing transfer layer: DK 173619 B1 14

Linear, saturated polyester (Vitel PE 700 4.0 parts by weight -Goodyear)

Methylethyl ketone 30.0

Toluene 31.0 - "-

White pig, graft, zinc sulfide (Sachtolith L 25.0 - Sachtleben HiabH)

Ethyl cellulose N7 (Hercules) 1.0

Blaze orange T 15 (Dayglo) 9.0

The transfer layer of the obtained band had a good coverage, was colored (orange) and was fluorescent.

5

Example1 4.

Example 1 was changed by using the following composition to form the dye-containing transfer layer:

Styrene-isoprene-styrene copolymer (about 4.7 parts by weight of rifle TR 1107 - Shell)

Methyl ketone 42.0

Toluene 42.0

Redglo Soluble Toner GF 13 (Redglo) 0.8

Ethyl cellulose N 22 (Hercules) 1.0

Aluminum stearate alugel TH 34 (Bar- 8.0 locher)

Silica (Aerosil 200 - Degussa) 1.0 parts by weight

The obtained transfer band's transfer layer was transparent and colored (orange).

Example 5.

DK 173619 B1 15

Example 1 was changed by using the following composition to form the dye-containing transfer layer;

Vinyl Propionate Based Polymer Dispersion 20.0 parts by weight (propiophane 6D - BASF)

Titanium Dioxide (Kronos RNCX) _30, 0_____________

Aluminum Silicate P 820 5.0 - "-

Water __ 28_j_5_ _

Walocel MW 50 GB (Wolff & Co.) _______ 1.0 ..............................

I soup call ano 1 _____ 14.0 __________

Aqueous solution of a silicone-free, ha 1.0 - "- liquefied organic compound (antifoam SF - Hoechst AG) _____ ____ ___________

Sodium dioctyl sulfosuccinate (Lutensite 0.5 ABO / wetting agent - BASF) _____________ __________ _____________ 5

The transfer band obtained layer had a good coverage and was white.

10

Claims (16)

A multilayer, flexible self-adhesive transfer tape for covering text or drawing by manual application, comprising an auxiliary support member and a contact adhesive layer between which is disposed a binder-containing transfer layer that adheres more strongly to the contact adhesive layer than to the auxiliary support body 10. in that the binder-containing transfer layer contains a tear-off aid in the form of a soluble cellulose derivative. Transfer belt according to claim 1, characterized in that the tear aid is present in the transfer layer in an amount of approx. 0.5-5% by weight. Transfer belt according to claim 1 or 2, characterized in that the cellulose derivative is ethyl cellulose. Transfer belt according to at least one of claims 1-3, characterized in that the auxiliary support body consists of a plastic and / or a silicone coated paper. 25 Transfer belt according to at least one of claims 1-4, characterized in that the transfer layer contains a polyurethane as a binder. Transfer belt according to claim 5, characterized in that the polyurethane is an aliphatic single-component polyurethane. DK 173619 B1 Transfer tape according to at least one of claims 1-6, characterized in that the transfer layer contains a coloring agent. Transfer tape according to claim 7, characterized in that the colorant is a pigment. Transfer tape according to claim 8, especially for correction purposes, characterized in that the pigment is a white coverage pigment with good coverage. Transfer tape according to claim 8, especially for marking purposes, characterized in that the pigment is an organic or inorganic colored pigment. 15 Transfer tape according to claim 7, in particular for highlighting text characters and illustrations, characterized in that the colorant is a fluorescent dye. Transfer belt according to at least one of claims 1 to 11, characterized in that the transfer layer, in the case of containing a basic dye, contains a binder for this. Transfer belt according to at least one of claims 1 to 12, characterized in that the ratio of the thickness of the contact adhesive layer to the thickness of the transfer layer is between approx. 1: 4 and approx. 1:12. Conveyor belt according to claim 13, characterized in that the thickness ratio is between approx. 1: 8 and approx. 1:10. DK 173619 B1 Process for preparing a transfer belt according to at least one of claims 1 to 14, characterized in that a solvent solution containing a tear-off aid in the form of a soluble cellulose derivative is applied to a flexible auxiliary body by conventional application methods. at elevated temperature, then an aqueous dispersion containing a contact adhesive is applied to the formed transfer layer by conventional application methods and the water is then evaporated. Use of the conveyor belt according to at least one of claims 1-14 in coiled form in a hand tool.