EP3863861A1

EP3863861A1 - Transfer paper for transferring images to substrates

Info

Publication number: EP3863861A1
Application number: EP19787202.1A
Authority: EP
Inventors: Bülent Öz
Original assignee: Forever GmbH
Current assignee: Forever GmbH
Priority date: 2018-10-11
Filing date: 2019-10-10
Publication date: 2021-08-18
Also published as: US20210379918A1; WO2020074663A1; DE102018125221A1; US11458756B2

Abstract

The present invention relates to a transfer paper for transferring images to substrates, comprising: a carrier with a wax coating; a layer (A) disposed thereon, containing a wax emulsion, a binding agent, an inorganic crystalline substance and a pigment; a layer (B) disposed on the layer (A), containing an organic polymer, an inorganic crystalline substance, a fixing agent, a copolymer and a pigment; and a layer (C) disposed on the layer (B), containing an organic polymer, a binding agent, an inorganic crystalline substance, a wax emulsion, a copolymer and a pigment. The invention also relates to a method for transferring images to substrates using the transfer paper.

Description

Transfer paper for transferring images to substrates

The present invention relates to a system for transferring images to substrates (transfer printing), such as textile documents, in particular T-shirts.

The invention also relates to a corresponding method for transferring images to solids.

When transfer printing, i.e. the transfer of images to substrates, such as textile documents, with the help of so-called transfer papers, to which the image to be transferred is applied in advance, under increased pressure and

Temperature conditions, there is often an undesirable

Background transfer, namely for transferring parts of the coating of the transfer paper that are not part of the illustration.

In order to prevent this, additional work steps, such as contour cutting on the transfer paper and subsequent weeding, are necessary and / or different temperatures have to be used when preparing the

Transfer paper and during the actual transfer process.

Especially with dark substrates, such as dark colored or black ones

Textiles, the color of the transferred image, in particular the strength and brilliance of the colors when using the single-sheet systems available on the market, which are basically produced for light-colored textiles, are not satisfactory.

Another criterion is the wash resistance of the transferred image on the substrate, which is often unsatisfactory.

The currently known solutions for transfer transfer without background to "dark-colored and black" substrates and fabrics with a correspondingly good strength, brilliance of colors and good wash resistance are currently limited to so-called two-sheet systems. A two-sheet system for transferring images to is known

Substrates, wherein a printable carrier (component A), which comprises the image in the form of an at least partial surface toner layer, and a component B, comprising a carrier and a polymer layer arranged thereon and a further opaque layer (WO 2013/159922 A1). This system is a

"Self-weeding" system, whereby essentially only the printed areas are transferred to the substrate without the need for one

Contour cutting and weeding. However, it is disadvantageous that two different sheets have to be handled, and the transfer process requires two steps under elevated temperature and pressure conditions and an additional separation step of components A and B.

The image is advantageously applied to the carrier material / transfer paper by means of digital printing, laser printing, in particular by means of

(Color) copiers or (color) laser printers, inkjet printers, using commercially available inks or toners.

The present invention has therefore set itself the task of a simplified system and method for transferring images to substrates

to provide that overcomes the disadvantages mentioned above.

The present invention therefore relates to a transfer paper for transferring images to substrates, comprising a support with one or more wax coatings; a layer (A) arranged thereon, containing a wax emulsion, a binder, an inorganic crystalline substance and a pigment; a layer (B) arranged on the layer (A), comprising an organic polymer, in particular a polydiallyldimethylammonium chloride, a binder, a fixing agent, a copolymer and a pigment; a layer (C) arranged on the layer (B), comprising an organic polymer, in particular a polydiallyldimethylammonium chloride, a wax emulsion, a copolymer, an inorganic crystalline substance, and a pigment. The present invention represents a single-sheet solution for light-colored and, above all, dark-colored and black substrates, in particular dark-colored and black textiles, fabrics and solids.

The invention provides a so-called self-weeding one-sheet system, in which the transfer paper is printed with an image to be transferred, the printed transfer paper with the printed side is arranged on a substrate, the substrate with the transfer paper arranged thereon under the action of pressure and exposed to temperature, e.g. by means of a thermal transfer press or an iron, the transfer paper is pulled off the substrate in such a way that the unprinted areas remain on the support of the paper and the printed areas, i.e. the image, remain on the substrate. The carrier is removed in the warm or hot state (so-called "warm peel" or "hot peel"). When warm, that means

Deducted after a waiting period following the transfer process. The waiting time is typically up to approx. 15 seconds. When hot, this means that the device is removed immediately after the transfer process. The removal / separation thus takes place essentially in the region of the temperature of the pressing process or somewhat lower, in particular above room temperature.

The present invention is particularly suitable for the transmission of

Images on dark substrates, such as dark or black textiles.

The image is applied to the transfer paper using customary printing processes, advantageously using digital printing, laser printing, in particular using (color) copiers or (color) laser printers, inkjet printers, commercially available inks or toners advantageously being used.

Water-soluble or solvent-containing inks, sublimation inks, polymer inks, so-called flexo inks, screen printing inks, offset inks or the like are suitable as inks for the purposes of the present invention. Prefers sublimation inks are used to apply the image to the transfer paper.

Toners consist of the corresponding color pigments in a plastic matrix, usually made of polyester with a melting range of e.g. approx. 80 - 120 ° C and any auxiliary materials. The layer thickness of the toner layer is at the usual technical values and is typically 5 - 50, preferably 5 - 20 g / m2 (in basis weight).

Carriers for transfer papers are known per se and can be made from nonwovens, in particular based on cellulose fibers, such as coated or

uncoated paper or cardboard or plastic films. The carrier is e.g. a film, cardboard or paper, especially a paper with a basis weight of z. B. approx. 80-150, preferably approx. 90-100 g / m2, such as a machine-smooth paper suitable for (color) copiers, (color) laser printers or ink-jet printers.

At least one surface of the carrier or paper mentioned is equipped with a polymer coating (also referred to below as a wax layer) made of polyolefins, polyolefin copolymers or polyurethanes with a layer thickness of approximately 20-60, preferably approximately 25-50 g / m 2.

As polyolefins, for example, LDPE optionally with maleic anhydride, EVA with approx. 7-28%, preferably approx. 7-15% VA content,

Ethylene acrylic acid copolymers or ethylene methyl acrylate copolymers with approx. 5-12% acrylic acid, ethylene butyl acrylate copolymers with approx. 5-20% acrylate are used, which preferably have a melt index according to ASTM-D-1238 (MFI) of approx. 3.5 -22, preferably approx. 7-15 g / 10 min at 2.16 kg / 190 ° C.

The layer preferably contains wax. As waxes come e.g. Paraffins or paraffin waxes or mixtures of paraffin waxes with LDPE, in

Consideration. The waxes typically have melting points in the range of approx. 60 - 100 ° C. In particular, between the carrier surface and the

Extrusion layer can also be arranged a wax layer, the

typically a layer thickness of e.g. 10 - 20 g / m2.

The wax layer can have one or more layers. The is preferred

Layered wax layer.

Methods for changing the surface structure of the support, e.g. by

Treatment of the surface by means of profile rollers or the like are also familiar to the person skilled in the art.

To improve the wettability of the surface and the adhesive force of the inks or toners, the surface of the carrier can optionally be another

Surface treatment to increase the surface tension are subjected, in particular, according to the invention, a plasma or corona treatment.

A layer (A) is arranged on the wax coating of the carrier, which comprises the following ingredients (percentages relate to% by weight based on the total weight of the layer): a wax emulsion, in particular based on polyethylene wax. The proportion of the wax emulsion is typically approximately 15-40%, in particular approximately 20-30%, a binder based on polyurethane for the elasticity. The share of

Binder is typically about 40-70%, in particular about 40-60%, an inorganic crystalline substance, such as in particular silica, but also calcium carbonate or concrete. The proportion of the inorganic crystalline substance is typically approximately 5-35%, in particular approximately 10-25%, of a pigment, advantageously in an acrylate-based binder. The proportion of the pigment is typically approximately 15-40%, in particular approximately 20-35%. The pigment is organic and / or inorganic and selected from

White pigment, color pigments, glitter, metal pigments, functional pigments or mixtures thereof. For example, the pigment can consist of several

Color pigments must be selected.

The structure of the white pigment preferably contains approximately 25-75% of one

White pigments, for example titanium dioxide, chalk, barium sulfate, zinc sulfide, zinc sulfate or kaolin, preferably titanium dioxide, about 25-75% of one

Plastic binder, which can be a polyolefin, polyolefin copolymer or polyurethane, reference being made to the above list of possible substances. Alternatively, a color pigment or functional pigment can also be used.

Functional pigments include pigments with reflective,

understood phosphorescent, fluorescent, photoluminescent or similar optical properties.

The layer thickness of the A-layer is approximately approx. 2-15 g / m2, preferably approximately 4-10 g / m2, in particular approximately 2-6 g / m2, particularly approximately 7-15 g / m2.

The A-layer advantageously has glass transition or softening temperatures in the range of approximately 130-200 ° C.

The function of the layer (A) is essentially the basic coloring. This is particularly important when one or more color pigments are included. In the case of monochrome images in particular, layer (A) then serves as the basic coloring of the image.

A layer (B) is arranged on the layer (A) and comprises the following ingredients (percentages relate to% by weight based on the

Total weight of the layer): an organic polymer, especially based on

Diallylmethylammonium chloride (polydiallyldimethylammonium chloride), which is used in particular to bind the color pigments. The proportion of the organic polymer is typically approximately 5-30%, in particular approximately 10-25%; a binder, especially based on polyurethane, for elasticity. The proportion of binder is typically about 5-30%, in particular about 10-25%; a fixative, especially based on polyurethane, to improve wash resistance. The proportion of fixative is typically about 1-20%, especially about 5-15%; a copolymer, especially based on vinyl acetate and ethylene, for absorbing the ink and drying it. The proportion of copolymer is typically approximately 10-35%, in particular approximately 15-30%. a pigment, especially in an acrylate-based binder. The proportion of the organic or inorganic pigment is typically approximately 25-50%, in particular approximately 30-45%.

Optionally, additives such as an inorganic crystalline substance, e.g.

Silicic acid or cellulose esters or other known processing aids can be added. Preferably in a proportion of about 5-35%, preferably 10-30%.

The following may also be included as further components: a plastic are particularly suitable polyesters, polyurethanes, polyacrylates and other compounds, for example flomo- or copolymers of vinyl acetate, vinyl alcohol,

Vinyl chloride, vinylidene chloride, methyl and / or ethyl acrylic acid or methacrylic acid, maleic acid compounds, styrene and others Cellulose esters and cellulose ethers such as ethyl cellulose, benzyl cellulose, cellulose propionates or acetates or butyrates or polyesters of terephthalic acid or polyamides such as nylon or perlon are also suitable.

The pigment is organic and / or inorganic and selected from

Color pigments must be selected.

The layer thickness of the B layer is approximately 5-20 g / m2, preferably approximately 10-15 g / m2, in particular approximately 5-12 g / m2, particularly approximately 13-20 g / m2.

The B layer advantageously has glass transition or softening temperatures in the range from approximately 130 to 200 ° C.

The function of the layer (B) is essentially to absorb the ink, in particular the color particles after sublimation of the ink and to improve the washability and elasticity of the image on the substrate.

Another function of layer (B) is good adhesion to layer (A).

A layer (C) is arranged on the layer (B), which comprises the following ingredients (percentages relate to% by weight based on the

Total weight of the layer): an organic polymer, in particular based on

Diallylmethylammonium chloride, which in particular the binding of

Color pigments are used. The proportion of the organic polymer is typically approx. 10-40%, in particular approx. 15-30%; a wax emulsion, especially based on polyethylene wax. The proportion of the wax emulsion is typically approximately 15-40%, in particular approximately 20-35%; a copolymer, especially based on vinyl acetate and ethylene, for the absorption of the toner or the ink and their drying. The share of

Copolymer is typically about 15-40%, especially about 20-35%; an inorganic crystalline substance, such as in particular silica, but also calcium carbonate or concrete. The proportion of the inorganic crystalline substance is typically approximately 5-30%, in particular approximately 10-25%; a pigment, especially in an acrylate-based binder. The proportion of pigment is typically approximately 10-35%, in particular approximately 15-30%.

The pigment is organic and / or inorganic and selected from

Color pigments must be selected. The pigment is advantageously a white pigment.

The layer thickness of the C layer is approximately 5-20 g / m2, preferably approximately 10-15 g / m2, in particular approximately 5-12 g / m2, particularly approximately 13-20 g / m2.

The C layer advantageously has glass transition or softening temperatures in the range of approximately 130-200 ° C.

Layer (C) is the printable layer to which the image is applied. Functionally, it essentially serves to absorb the ink, in particular the color particles after sublimation of the ink, and to adhere to the substrate.

Further functions of layer (C) are good adhesion to layer (B) and a covering of the substrate color.

In the case of monochrome images, the pigments of layer (A) are preferably selected from color pigments and thus specify the basic color of the image. The pigments of layers (A) and (B) are advantageously chosen from color pigments of the same color. By specifying the basic color of the illustration in in this case, the color of the ink takes precedence. A transparent ink or toner could even be used.

The pigment of layer (C) is preferably a white pigment. This serves to cover the color of the substrate. Furthermore, a metallic pigment can also be used to better cover the substrate surface

be added.

In the case of colored images, the pigments of layers (A), (B) and (C) are preferably chosen from white pigments. The ink, especially the color particles after sublimation of the ink, penetrate all layers (A) - (C) and result in a colored image on the substrate.

It is provided according to the invention that further optional layers can be present. It is possible, for example, that instead of one layer (B) there are also two layers (B) or instead of one layer (C) there are also two layers (C). In this case, the two layers (B) or (C) advantageously each have a smaller layer thickness on their own than when only one layer (B) or (C) is present.

It is also possible to have an optional layer (D), e.g. a metal layer made of metal pigments, which is arranged above the layer (C) and thus represents the outermost layer of the transfer paper.

The respective layers are preferably applied separately one after the other to the carrier, in particular with sufficient drying times.

The layers (A), (B) and (C), optionally further optional layers, can be formulated in such a way that they are formed by an alcoholic-aqueous fluid, such as the liquid phase of the ink, or by a melting toner under increased pressure. and temperature are activated, but the layer structures are essentially retained.

Without being bound by any theory, it is believed that the process of self-weeding of the printed transfect paper is caused by the fact that the outermost layer of the transfect paper, typically the layer (C), by interaction with the toner or the ink under pressure and

Temperature becomes sticky. Under these conditions, a melting toner or the solvent-containing medium of an ink will at least partially dissolve the layer (C) and thus cause stickiness to the substrate surface.

Layer (C) adheres to the substrate surface. The formulation of the layers causes a certain brittleness in the heat in the printed area, so that when the backing (backing paper) is peeled off, a kind of vertical break in the layer sequence (ie from layer (C) towards layer (B), layer (A) and possibly . the wax layer) takes place along the printed area and so the layers (B) and (A) and possibly parts of the wax layer are held by the layer (C) on the substrate, while in the unprinted area there is no adhesion to the substrate.

The present invention also relates to the use of the transfer paper according to the invention.

Another object of the present invention is a method for

Transfer images to a substrate using the

Transfer paper according to the invention.

The method according to the invention for transferring images onto substrates comprises

- the provision of a transfer paper according to the invention; - The application of the image on the layer (C) by means of a

Printing method, advantageously by means of digital printing, with printed and non-printed areas being defined on the layer (C);

- Applying the transfer paper to a substrate with the printed side (layer (C)) facing the surface of the substrate;

- Subsequent pressing of the arrangement of substrate and transfer paper at approx. 2-5 bar in the temperature range from a minimum of approximately 100-150 ° C to a maximum of approximately 200-250 ° C, for example approximately 100-250 ° C, particularly approximately 150 ° C up to a maximum of about

200 - 250 ° C, in particular from about 150 - 220 ° C, especially from about 150 - 200 ° C, also 180 - 220 ° C, typically for a minimum of about

15-20 seconds to a maximum of approximately 60 seconds, in particular approximately 15-45 seconds, preferably 15-30 seconds, the image being transferred to the substrate; and

- Tear off the carrier of the transfer paper in warm or hot

Status.

The method according to the invention can be carried out using conventional devices, so-called

Transfer presses are carried out.

According to one embodiment of the invention, after the image has been transferred to the substrate, the image is additionally treated.

So-called refinement is preferably carried out, in particular by

Applying a finishing foil, such as hot stamping foil or flock sheet. The specialist is familiar with the use of appropriate foils in the field of transfer printing (https: //www.forever- ots.de/produkt/hot-stamping-foils/; https://www.plottermarie.de/folien/825- veredelungsfolien-meterware.html; https://www.printequipment.de/heisspraege/; https://lfp-partner.eu/datenblatt/forever/HSF-Anleitung-DE.pdf;

https://www.forevertransferpaper.com/no-cut-flock-sheets).

The hot stamping foil is usually applied at temperatures in the range from approximately 150 to 200 ° C. and medium to high pressures of approximately 3 to 6 bar, preferably high pressures of approximately 5 bar for approximately 10 to 120 seconds, preferably approximately 25 to 45 seconds. The hot stamping foil is usually removed when it is cold.

The invention therefore also relates to a combination of the transfer paper according to the invention with a finishing film. The combination can be in a spatially separated form or in a common packaging.

Unless otherwise stated or the context clearly indicates otherwise, percentages relate to the weight, in doubt to the total weight of the mixture.

The invention also relates to all combinations of preferred configurations, insofar as these are not mutually exclusive. The information "about" or "approx." in connection with a number means that at least 10% higher or lower values or 5% higher or lower values and in any case 1% higher or lower values are included. Where an indefinite article such as "a", "one" or "one" has been used in relation to a term, this also includes the meaning "one or more" or "at least one".

Claims

1. Transfer paper for transferring images to substrates, comprising a support with a wax coating;

(A) a layer arranged thereon, containing a wax emulsion, a binder, an inorganic crystalline substance, such as, in particular, silica, but also calcium carbonate or bentonite, and a pigment;

(B) a layer arranged on the layer (A), containing a

organic polymer, in particular based on

Diallylmethylammonium chloride, a binder, a fixing agent, a copolymer and a pigment;

(C) a layer arranged on the layer (B), containing a

organic polymer, in particular based on

Diallylmethylammonium chloride, a binder, an inorganic crystalline substance such as in particular silica but also calcium carbonate or bentonite, a wax emulsion, a copolymer and a pigment.

2. Transfer paper according to claim 1, wherein the carrier is selected from

Paper, foil or cardboard.

3. Transfer paper according to claim 1 or 2, wherein the pigment is selected from white pigment, color pigments, glitter, metal pigments,

Functional pigments or mixtures thereof.

4. Transfer paper according to claim 3, wherein the pigment in layer (A) is a white pigment or one or more color pigments.

5. Transfer paper according to one of claims 1 to 4, wherein the organic polymer in layer (B) and / or (C) is a polydiallyldimethylammonium chloride.

6. Transfer paper according to one of claims 1 to 5, wherein layer (B) additionally contains an inorganic crystalline substance.

7. A method of transferring images to substrates, comprising

- the provision of a transfer paper according to any one of claims 1-6;

- The application of an image on the layer (C) by means of a

Printing method, wherein printed and unprinted areas are defined on the layer (C);

15-20 seconds to a maximum of approximately 60 seconds, in particular approximately 15-45 seconds, preferably 15-30 seconds, the image being transferred to the substrate; and - Tear off the carrier of the transfer paper when it is warm or hot.

8. Use of the transfer paper according to one of claims 1 to 6 for transferring images to substrates, in particular dark-colored or black textiles.