DE112011105593T5 - recording medium - Google Patents

Abstract

A recording medium contains a substrate and a deinking agent, which is coated in the substrate, on the substrate in a layer or both in the substrate and on the substrate in a layer. The deinking agent is selected from an unsaturated fatty acid having 19 to 23 carbon atoms and combinations of these unsaturated fatty acids. The deinking agent interacts with an ink that is printed on the recording medium to remove the ink during a deinking process.

Description

BACKGROUND

The present disclosure generally relates to recording media.

Recycling processes can be used to regenerate useful cellulose fibers from waste paper. Some recycling processes include a deinking process that removes ink from the waste paper pulp. In some cases, the deinking process involves applying deinking chemicals to waste paper that interacts with and removes ink particles from the paper. Such deinking processes can be challenging in some cases for the recycling of some digitally printed papers.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of examples of the present disclosure will become apparent with reference to the following detailed description and drawings, in which like reference numbers correspond to similar but perhaps not identical components. For the sake of brevity, reference signs or features having a function described above may or may not be described in conjunction with other drawings in which they occur.

1 schematically illustrates an example of a recording medium;

2 schematically illustrates another example of a recording medium;

3 Fig. 12 schematically illustrates yet another example of a recording medium;

4 Fig. 10 is a flowchart illustrating an example of a deinking process;

5A and 5B are schematic representations of hand samples from non-depressed pulps ( 5A ) and deprived pulps ( 5B ), which pulps were from a liquid electrophotography (LEP) printing medium and oleic acid was used as a deinking chemical when converted into pulp;

6A and 6B are schematic representations of hand samples from non-depressed pulps ( 6A ) and deprived pulps ( 6B ), the pulps being from an LEP printing medium and erucic acid used as a deinking chemical when converting to pulp;

7A and 7B are schematic representations of hand samples from non-depressed pulps ( 7A ) and deprived pulps ( 7B ), wherein the pulps came from a dye ink printing medium and oleic acid was used as a deinking chemical when converting into pulp, and 7C Figure 3 is a schematic representation of a membrane filter showing the presence of dissolved ink left after conversion to pulp and flotation in a flotation tank;

8A and 8B are schematic representations of hand samples from non-depressed pulps ( 8A ) and deprived pulps ( 8B ), wherein the pulps came from a dye ink printing medium and erucic acid was used as a deinking chemical when converting into pulp, and 8C Figure 3 is a schematic representation of a membrane filter showing the presence of dissolved ink left after conversion to pulp and flotation in a flotation tank;

9A and 9B are schematic representations of hand samples from non-depressed pulps ( 9A ) and deprived pulps ( 9B ), wherein the pulps came from a pigmented ink-printing medium and oleic acid was used as a deinking chemical when converting into pulp, and 9C Figure 3 is a schematic representation of a membrane filter showing the presence of dissolved ink left after conversion to pulp and flotation in a flotation tank;

10A and 10B are schematic representations of hand samples from non-depressed pulps ( 10A ) and deprived pulps ( 10B ), wherein the pulps came from a pigmented ink printing medium and erucic acid was used as a deinking chemical when converting into pulp, and 10C Figure 3 is a schematic representation of a membrane filter showing the presence of dissolved ink left after conversion to pulp and flotation in a flotation tank;

11A and 11B are schematic representations of hand samples from non-depressed pulps ( 11A ) and deprived pulps ( 11B ), the pulps being from an offset printing medium and oleic acid used as a deinking chemical when converting to pulp; and

12A and 12B are schematic representations of hand samples from non-depressed pulps ( 12A ) and deprived pulps ( 12B ), the pulps being from an offset printing medium and using erucic acid as a deinking chemical when converting to pulp.

DETAILED DESCRIPTION

Processes for the recycling of printed waste paper sometimes involve converting the waste paper into a pulp, whereupon the pulp is contacted with deinking chemicals. The deinking chemicals interact with the ink and then separate the ink from the waste paper. This recycling process has been well suited for use with offset-printed waste paper, but there may be some challenges in separating and removing digital inks (such as liquid-electrophotography (LEP) or other digitally printed inks) from waste paper. For example, conventional deinking involves the removal of ink particles that fall within a size range of about 10 μm to about 100 μm. Some challenges in removing digital ink, particularly digital pigmented inkjet inks or digital inkjet dye inks, include finding a solution to aggregate the pigment particles or dye molecules to a desired size range and changing the physical properties of the particles / molecules from too hydrophilic to more hydrophobic. It has been found that some existing deinking chemicals in some cases do not efficiently separate the ink from fibers of a waste paper. It is believed that the challenges are / are at least partially related to the material composition and / or properties of the digital ink, which in some cases may adversely or not interact with the deinking chemicals used by the recycle paper mill. In many cases, the digital ink can not be separated from the waste paper and removed to the extent necessary for adequate waste paper recycling.

The inventors of the present disclosure have determined that digital inks can be suitably and successfully separated from wastepaper by choosing a correct deinking agent. As used herein, a deinking agent is a component of a substrate or layer that is applied to the substrate while a deinking chemical is a component that is added during the conversion phase in pulp to a deinking process. It should be understood that examples of the deinking chemicals disclosed herein may also be used as examples of the deinking agent. Certain fatty acids (such as those having a carbon chain length of 18 carbons or less (eg, oleic acid) or those having a carbon chain length of 24 carbons or more (eg, nervonic acid) have been successfully used as a deinking chemical for the alkaline deinking used by offset printing. It has been found, however, that these fatty acids are less effective for deinking other selected digital prints, such as: As the deinking of LEP and / or thermal inkjet printing. In contrast, it has also been found that erucic acid (which has a carbon chain length of 22 carbon atoms) effectively deprives digital LEP prints as well as other prints, e.g. Digital pigmented inkjet inks or digital inkjet dye inks and non-digital prints.

It is believed that unsaturated fatty acids having 19 to 23 carbon atoms or combination of these unsaturated fatty acids can be successfully incorporated as a deinking agent in or on a substrate. Examples of such unsaturated fatty acids include 18-nonadecanoic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, erucic acid and docos-21-enoic acid. If the unsaturated fatty acid has the chemical formula C ₂₂ H ₄₂ O _2, it is assumed that the double bond at any position along the carbon chain may be present. For example, the C ₂₂ H ₄₂ O ₂ acid may be erucic acid or docos-21-enoic acid.

At least in part, based on the results disclosed herein, it is believed that an erucic acid deinking agent can be incorporated into the substrate (e.g., between the cellulosic fibers of the paper or as part of a coating layer formed on the paper), and the inventors In the present disclosure, it is believed that the erucic acid contained as part of the substrate may be effective as a non-liquid deinking agent. As a component of the substrate, it is considered that the deinking agent of an unsaturated fatty acid having 19 to 23 carbon atoms (eg, the erucic acid deinking agent) during the pulping stage and the flotation stage of a deinking process is very close the ink is. It is believed that this will deink ink from the underlying substrate for digital printing as well as for non-digital prints, including, for example, paper. B. offset inks, advantageously improved. In particular, with respect to erucic acid, since erucic acid emulsifies in water, it is considered that introduction of a minimum amount of erucic acid into the substrate in papermaking brings no trouble. It is believed that this is at least partly due to the fact that erucic acid forms a workable emulsion in water, and that this emulsion can be easily incorporated into the slurry from which the paper base is made or into the coating formed on the paper base. It is also believed that erucic acid or any unsaturated fatty acid having 19 to 23 carbon atoms does not adversely affect the integrity of the substrate.

In the figures, an example of the recording medium 10 of the present disclosure schematically in FIG 1 shown. In this example, the recording medium contains 10 a substrate 12 and one in the substrate 12 introduced deinking agent DA, 14 ,

The substrate 12 for the medium 10 may be selected from any raw material containing any type of pulp fiber, and may be referred to herein as a pulp-based substrate or a cellulose fiber-based substrate. The substrate 12 may consist of pulp fibers derived from wood, such as. Hardwood trees (eg deciduous trees such as birch, oak, beech, maple and eucalyptus) and / or softwood trees (eg coniferous trees such as species of fir) Spruce and pine, for example frankincense pine, Elliott pine, prickly spruce, balsam fir and Douglas fir), and these pulp fibers can be made by any known transformation process in pulp. The substrate 12 may also consist of non-wood fibers (such as bagasse, straw and bamboo) or recycled fibers. The raw material for the substrate 12 Can be made with wood containing fibers, such as. Thermomechanical pulp (TMP) fibers, chemothermomechanical pulp (CTMP) fibers, mechanical refiner pulp fibers (RMP), groundwood pulp fibers (GW), and / or the like. Furthermore, the raw material may contain one or more fillers and / or binders for controlling the physical properties of the substrate 12 contain. Examples of fillers include carbonates (eg, ground calcium carbonate and precipitated calcium carbonate), titanium dioxide, clays (eg, kaolin), silicates, oxides, zeolites, talc, and combinations thereof. An example for. a binder is styrene-butadiene rubber (SBR). The filler and / or binder may be added to the fibrous structure of the furnish or added in a size press.

In one example, the substrate may be 12 Some additives include, for example, internal sizing agents, dry reinforcing agents, wet reinforcing agents, fixatives, pH regulators and / or colorants. Examples of internal sizing agents include fatty acids, metal salts of fatty acids, alkyl ketene dimer emulsion products, epoxidized higher fatty acid amides, alkenylic anhydride emulsion products and rosin derivatives, alkylated succinic anhydride emulsion products and rosin derivatives and / or combinations thereof. Examples of dry reinforcing agents which may be used include anionic polyacrylamides, cationic polyacrylamides, amphoteric polyacrylamides, polyvinyl alcohol, cationized starch, plant galactomannan and / or combinations thereof. Examples of moisturizing agents include polyamine-polyamide-epichlorohydrin resins, and the fixing agents include, for example, water-soluble aluminum salts, aluminum chloride and / or aluminum sulfate. Further, examples of the pH regulator include sodium hydroxide, sodium carbonate and / or sulfuric acid, and examples of colorants include pigments, dyes and / or fluorescent brighteners.

The deinking agent DA, 14 is any unsaturated fatty acid having 19 to 23 carbon atoms or combinations of these unsaturated fatty acids. If the selected unsaturated acid has the chemical formula C ₂₂ H ₄₂ O _2, it is assumed that can be located, the double bond at any position along the carbon chain. In one example, the deinking agent is DA, 14 Erucic acid. In the in 1 example shown is the deinking agent DA, 14 in the material of the substrate 12 brought in. The deinking agent DA, 14 can during paper making in the substrate 12 are introduced and, when introduced, distributed in the mass of the paper formed. For example, the substrate 12 a paper base is formed by the chemical and / or mechanical treatment of wood pulp (for example by a conventional papermaking process) and then the deinking agent DA, 14 is added to the paper base. In cases where the substrate 12 Contains fillers, the deinking agent DA, 14 be added to the paper base at the same time as the fillers are added, or the deinking agent DA, 14 can be added in a separate step. In cases where the substrate 12 contains no fillers, the deinking agent DA, 14 be added alone as soon as the paper base is formed.

In one example, the amount of deinking agent DA, 14 in the substrate 12 from about 0.2% to about 0.8% by weight of the total weight percent of the substrate 12 , This area is suitable for most, if not all, used papers. It is assumed that more than 0.8% by weight of the deinking agent DA, 14 in the substrate 12 up to about 2 percent by weight of the total weight percent of the substrate 12 , The greater amount of deinking agent DA, 14 can be used, for example, for graphic papers where high ink coverage may occur (eg, more than 50% of the paper is covered in ink). It was found to be a minimal in the substrate 12 Existing amount of deinking agent DA, 14 (eg, about 0.2% to about 2% by weight) is enough of the deinking agent to interact effectively with an ink with which the medium 10 (ie a print) was printed to remove the ink during deinking. Furthermore, it is assumed that the minimum amount of deinking agent DA, 14 also in the substrate 12 can be introduced without adversely affecting the papermaking process. It is assumed that, for example, when using larger amounts of the deinking agent DA, 14 the excess deinking agent DA, 14 can aggregate to larger particles and remain in the slurry during papermaking.

In one example, the deinking agent is DA, 14 and at least one further deinking agent (not shown) in the substrate 12 brought in. It is assumed that the presence of the further deinking agent further improves the deinking process (for example, makes the deinking process more efficient, at least as regards the period of deinking). The other deinking agent (s) is / are from another fatty acid, such as. A saturated fatty acid, another unsaturated fatty acid or combinations thereof. Examples of the saturated fatty acid which can be used as the other deinking agent include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, Stearic acid, nonadecanoic acid, arachic acid, heneicosanoic acid, behenic acid, tricosanoic acid, lignoceric acid, pentacosanoic acid, cerotic acid, heptacosanoic acid, montanic acid, nonacosanic acid, melissic acid, hentriacontanoic acid, lacceric acid, psyllic acid, geddic acid, ceroplastinic acid, hexatriacontanoic acid and combinations thereof. Examples of other unsaturated fatty acids which may be used as the further deinking agent include α-linolenic acid, stearidonic acid, eicosapentaenoic acid, docosahexaenoic acid, linoleic acid, γ-linolenic acid, dihomo-γ-linolenic acid, arachidonic acid, oleic acid, eicosanoic acid, nervonic acid, mead ' acid and combinations thereof. In one example, the more fatty acid that is used in combination with the deinking agent DA, 14 is selected from oleic acid (an unsaturated fatty acid) and / or arachidic acid (a saturated fatty acid). It should be understood that the additional deinking agent is a single deinking agent (a saturated fatty acid or an unsaturated fatty acid), a combination of two or more saturated fatty acids, a combination of two or more unsaturated fatty acids or a combination of one or more more saturated fatty acids and one or more unsaturated fatty acids can be selected.

In one example, the amount of the further deinking agent that is in the substrate 12 is present in the range of about 0.2% to about 2% by weight of the total weight percent of the substrate 12 and in another example, the amount of the further deinking agent ranges from about 0.2% to about 0.6% by weight of the total weight percent of the substrate 12 ,

Another example of the recording medium 10 ' is schematic in 2 displayed. The medium 10 ' contains a substrate 12 ' and one on the substrate 12 formed layer 16 , It should be understood that the terms "formed on,""disposedon,""appliedto,""createdon," and the like, as used herein, are broadly defined to encompass a variety of divergent layering arrangements and ordering techniques. These arrangements and techniques include i) direct attachment of the layer 16 on another layer (eg the substrate 12 ' ) with no intervening layers in between, ii) the attachment of the layer 16 on another layer (eg the substrate 12 ' with one or more layers therebetween; and iii) the application of a layer (different from the layer 16 ) on the substrate 12 (shown in 1 ) with one or more layers therebetween, provided that the one layer which is "formed", "arranged", "applied" or "created" on the further or on the further layer is somehow supported by the further layer (despite the presence of one or more additional layers of material therebetween). The other layer (s) (ie not the layer 16 ) may be, for example, a first rough coating layer for plain paper or an upper smooth coating for graphic papers. In some cases, an adhesive layer may be incorporated between layers, such as e.g. B. between the layer 16 and the substrate 12 ' or between a smooth coating and the substrate 12 , Further, the terms "directly formed on,""directly disposed on,""directly applied to,""directly created on," and / or the like are broadly defined herein to encompass (a) matter (s) in which / a given layer (eg the layer 16 ) on another layer (eg the substrate 12 ' ) without any intervening layers between them is attached. Any statement made herein that indicates that one layer is on another layer is to be understood to mean that the layer in question that is "on" that particular layer is the outermost of the two layers in relation to incoming ink materials dispensed by the particular printing system. It should be understood that the characterizations listed above are independent of the orientation of the materials of the recording medium being considered.

In one example, the substrate may be 12 ' be the pulp or fiber based substrate material described above. In this example is on the substrate 12 ' a coating layer 16 educated. The recording medium 10 ' may therefore be referred to as a coated substrate.

The coating layer 16 may contain inorganic pigments / fillers (eg calcium carbonate, kaolin etc.), natural or synthetic binders (eg styrene-butadiene rubber (SBR), polyvinyl alcohol, starches, polyethyleneimine, polyamide resins, polyesters, aqueous polyurethane dispersions, polyethylene Acrylic acid or the like or combinations thereof) and possibly further additives (eg a whitening agent such as zinc oxide, titanium oxide and alumina).

In one example, the deinking agent is DA, 14 in the layer 16 brought in. In another example, the deinking agent is DA, 14 and one or more further deinking agents in the layer 16 brought in. The one or more other deinking agents is / are selected from saturated fatty acids, unsaturated fatty acids, or combinations thereof, and examples of these other deinking agents are listed above.

The medium 10 ' can be made by using the deinking agent DA, 14 a combination of the pigment (s) / filler (s) and binder (s) to form a relatively dilute coating layer composition (e.g., the coating layer composition may contain from about 2% to about 5% by weight solids in an aqueous mixture). This coating layer composition may then be applied to one surface of the substrate 12 ' be applied to the layer 16 to build. In one example, the composition is applied to a single area (eg, S ₁ ) of the substrate 12 ' applied, or it is applied to both surfaces (eg, opposite surfaces S ₁ , S ₂ ) of the substrate 12 ' applied. The composition may be on the substrate 12 ' be applied to the coating layer 16 using a dosing sizing press, a sizing press, roll coating, conventional slot die processing, knife coating, slot die cascade coating, curtain coating, bar coating and / or gravure air knife coating. In one example, the coating layer composition becomes on the base substrate 12 ' applied with a coating machine using a combination of a sponge and a metering blade, followed by heating and / or drying. In some cases, spray coating, dip coating and / or casting coating techniques may also be used.

In the in 2 shown example medium 10 ' contains the substrate 12 ' not the deinking agent DA, 14 in this. In yet another example, as in 3 shown, contains the medium 10 '' a substrate 12 in which the deinking agent DA, 14 is introduced, and in which a layer 16 on the substrate 12 is formed. In this example, the deinking agent is DA, 14 also in the shift 16 brought in. This in 3 shown example medium 10 '' can be made by using the deinking agent DA, 14 as described above during preparation in the substrate 12 is introduced and the substrate 12 then coated with the coating layer composition as described above to form the layer 16 to build.

The medium 10 . 10 ' . 10 '' can be printed with any suitable ink and printing system.

Fibers of the medium 10 . 10 ' . 10 '' to which an ink may be applied to form a printed medium (or print) may be recycled by a conventional paper recycling process. For example, the printed medium may be placed in a recycled paper mill, and then the dye of the ink applied to the printed medium may be separated from the fibers of the medium 10 . 10 ' . 10 '' be separated to form a de-inked pulp. Separating the dye from the medium 10 . 10 ' . 10 '' may be referred to herein as a deinking process, and an example of the deinking process is in 4 shown in a diagram. This deinking process involves converting the printed medium on whose surface the ink has been printed into pulp in the presence of a deinking liquid to form a slurry, as indicated by the reference numeral 100 shown. The conversion to pulp can be accomplished by placing the printed media in a pulper of the recycled paper mill and the printed medium is then chopped into smaller pieces. In a neutral or near-neutral deinking process, conversion to pulp occurs in the presence of neutral or near-neutral deinking chemicals (eg, those chemicals having a pH in the range of about 7 to about 8). In an alkaline deinking process, the conversion to pulp occurs in the presence of alkaline deinking chemicals, such as. NaOH (a modifier of alkalinity), a Na ₂ SiO ₃ solution (an alkalinity buffering agent), oleic acid or another suitable acid, and H ₂ O ₂ (a bleaching agent). It is believed that some deinking chemicals (eg, oleic acid) during conversion to pulp will be at least partially due to the required specifications (such as those dictated by the deinking method used) for the recovered pulps for particular paper End products (eg tissue paper) can not be used. It should be understood that either during the neutral / near-neutral deinking process or the alkaline deinking process, water may be added to the pulper while the printed media is being chopped, thereby converting the printed media into a slurry of pulp and ink.

During the pulp conversion process, the deinking agent DA interacts 14 in and / or on the medium 10 . 10 ' . 10 '' with the ink, with which the medium 10 . 10 ' . 10 '' was printed. During this interaction, the ink is broken up into smaller particles that are removable during a flotation process, described below. Inks that may be removed from a printed medium by the deinking process described herein include LEP inks, pigmented inkjet inks, inkjet dye inks, and offset inks such as the like. For example, water-based inks for aqueous flexo offset printing, oil-based inks for offset sheet fed, and solvent-based inks (eg, those containing toluene) for roto-gravure offset printing.

Regardless of the deinking process used to prepare the slurry, examples of the method after making the slurry include performing a flotation process as indicated by the reference numeral 102 in 4 shown. The flotation process is used to separate the ink from the slurry.

Using a neutral or near-neutral deinking process, the slurry is introduced into a foam flotation cell and then a collector (eg, a frother) is introduced into the slurry. An example of a suitable foamer is sodium dodecyl sulfate. The frother allows for the formation of foam which permits removal of the separated ink particles from the fibers. Since the foamer has an affinity for the now separated dye particles, in particular the dye particles adhere to the foam of the foamer. The foam has sufficient yield strength to transport a large distribution of dye particles into the top of the foam flotation cell. In one example, air may also be blown into the slurry. The air bubbles lift the dye particles as a thick foam that can be removed from the cell to the surface of the flotation cell.

When applying an alkaline deinking process, the slurry is introduced into a foam flotation cell. The flotation process of this example may take place in the presence or absence of a foamer.

In some cases, the pulp slurry is screened to remove any matter that may be denser than the pulp, such as the pulp slurry. As impurities or other foreign bodies. In one example, coarse and fine sieving can be performed by adding the slurry to e.g. B. is passed over or through a sieve with different sized slit openings to separate such substances from the slurry, and these substances can be collected with another mesh screen.

To further illustrate the present disclosure, examples are given herein. It should be understood that these examples are provided for purposes of illustration and are not to be considered as limiting the scope of the disclosed example (s).

EXAMPLES

example 1

Some saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids have been tested for deinking LEP inks. Print samples were made by printing different cellulose-based papers with LEP ink, each paper being de-inked with a different fatty acid. The amount of fatty acid used was in the range of about 0.2% per unit paper weight to about 2.0% per unit paper weight. Printing was done on an ^HP® Indigo 5500 digital press and the prints were deinked using a deinking laboratory setup using deinking chemicals during the pulping step. The deinking chemicals contained the selected fatty acid, about 0.6 weight percent sodium hydroxide, about 1.8 weight percent sodium silicate, and about 0.7 weight percent hydrogen peroxide, the weight percent of which is based on the weight of the paper products.

Tabelle 2: Tinten-/Schmutzpunkte von nicht deinkten Pulpen (UP), d. h. jenen, die keiner Flotation unterzogen wurden, und deinkten Pulpen (DP), d. h. jenen, die Umwandeln in Pulpe und Flotation unterzogen wurden, wobei ungesättigte Fettsäuren als Deinking-Mittel verwendet wurden

Tables 1 and 2 below set ink / dirt dots (A, measured in terms of dot area per unit area) of deinked pulp (DP) for both ink / dirt dots of 50 μm or larger (A ₅₀ ) and ink dots. / Dirt spots of 250 μm or larger (A ₂₅₀ ), where A ₅₀ and A _{250 are} each expressed in mm ² / m ² . The ink / dirt dots were determined by analyzing hand patterns using image analysis algorithms performed by a processor, and the algorithm (s) generated a distribution of dot diameters for the analyzed handsamples. Table 1: Ink / Dirt spots of non-depressed pulp (UP), ie those which have not been flotated, and deinked pulps (DP), ie those which have undergone pulping and flotation conversion, with saturated fatty acids as deinking agent were used

Table 2: Ink / Dirt spots of non-depressed pulp (UP), ie those which have not been subjected to flotation, and deinked pulps (DP), ie those which have undergone pulping and flotation conversion, with unsaturated fatty acids as deinking agent were used

As shown in Table 1 above, the ink / dirt dots (i.e., area of dots per unit area) decreased as the length of the saturated fatty alkyl chain increased from 12 carbons to 20 carbons. Fatty acids with carbon chain lengths of 22 and 24 carbons had relatively many ink / dirt spots that did not match the decreasing trend exhibited by the other fatty acids. Based on these data, it is believed that the saturated fatty acids used in and / or on the paper as a deinking agent may be suitably used for neutral or near-neutral deinking of non-digital inks; but the saturated fatty acids may not be suitable for deinking LEP inks.

Further, as shown in Table 2 above, it has been found that some of the monounsaturated fatty acids are very effective for deinking. The ink / soils of oleic acid (having 18 carbon atoms) were too many (ie, ink / dirt dots (A ₅₀ ) were greater than about 4,000 m ² / m ² after deinking (ie, de-inked pulp (DP)), and so on There was no appreciable change in dot count between non-deinked pulps (UP) and deinked pulps (DP) It is thus believed that oleic acid may be unsuitable as a substrate / paper component for achieving effective deinking of LEP inks. Dirt spots of nervonic acid (having 24 carbon atoms) were too many (ie, ink / dirt dots (A ₅₀ ) were greater than about 2000 mm ² / m ² after deinking (ie depressed pulp (DP)), although a noticeable change the dot count was observed between non-depressed pulp (UP) and depressed pulp (DP) It is thus believed that nerve acid as a substrate / paper component to achieve effective deinking of LEP inks may possibly be unsuitable It has been found, however, that erucic acid (which has 22 carbon atoms) is particularly effective for removing LEP ink / dirt spots. This is due, at least in part, to the noticeable change (which is at least an order of magnitude less) in the ink / dirt points (A ₅₀ ) between non-depressed pulp (UP) and de-inked pulp (DP). Furthermore, after deinking, it was determined that the erucic acid ink / dirt dots (A ₅₀ ) were 186 mm ² / m ² , which is significantly lower than the threshold of 600 mm ² / m ² (which is due to the parameters on the deinking Point card issued by the European Recycling Paper Council). These results indicate that erucic acid can be incorporated into and / or onto the substrate / paper and / or applied to achieve effective deinking of LEP inks.

It should be noted that the weight percent values in Examples 2-5 are based on the weight of the comparative paper sample or paper sample; whichever is discussed.

Example 2

5A and 5B are schematic representations of handsheets (ie, those who were not subjected to flotation) or deinked pulps a comparative LEP print medium sample were made of non-deinked pulps, wherein the ink Hewlett Packard EI 4.5-ink and the medium STERLING ^® ultra Digital ^TM Paper (available from Newpage Corp., Miamisburg, Ohio, USA). For the comparative LEP print media sample, oleic acid was used as a deinking chemical. 6A and 6B are schematic representations of handsheets were made of non-deinked pulps and deinked pulps a LEP print medium sample, wherein the ink Hewlett Packard EI 4.5-ink and the medium STERLING ^® ultra Digital ^™ paper (available from Newpage Corp., Miamisburg, Ohio, USA). For the LEP print media sample, erucic acid was used as a deinking chemical.

An alkaline deinking process was carried out for the comparative sample or for the sample. The alkaline deinking processes followed the protocol according to method 11p of INGEDE (International Association of the Deinking Industry). The deinking processes were performed with deinking chemicals, including about 0.3 weight percent sodium hydroxide and 0.9 weight percent sodium silicate. Further, as mentioned above, oleic acid was used as a deinking chemical when converting into pulp of the comparative LEP print media sample, and erucic acid was used as a deinking chemical when converting to pulp of the LEP print media sample. In each of the deinking processes, each of the acids was used in an amount of about 0.8% by weight.

The results obtained for the comparative LEP print media sample showed that poor deinkability of LEP prints occurred when oleic acid was used as a deinking chemical. As in 5B The ink / dirt points (A ₅₀ ) of the Comparative De-inked Pulp (DP) were 4403 mm ² / m ² , which was representative of the fact that after deinking there was still a significant amount of ink in the pulp. The results obtained for the LEP print media sample showed that good deinkability of LEP prints occurred when erucic acid was used as a deinking chemical. As in 6B At the ink / dirt points (A ₅₀ ) of the deinked pulp (DP), about 186 mm ² / m ^{2 was} measured, and at the ink / dirt points (A ₂₅₀ ) of the depressed pulp (DP), about 24 mm ^{2 was} measured / m ² measured. This was a significant change from the non-depressed pulp (UP) shown in 6A , and showed that deinking had removed a significant amount of the LEP ink from the pulp. In fact, after deinking, so few particles of the LEP ink remained that the average diameter (d _avg ) could not be measured.

These results further support the conclusion that oleic acid may be an inappropriate paper component for achieving effective deinking of LEP inks and that erucic acid may be a suitable paper component for achieving effective deinking of LEP inks.

Example 3

7A and 7B are schematic representations of handsheets (ie, those who were not subjected to flotation) or deinked pulps a comparative dye-based inkjet print medium sample were made of non-deinked pulps, wherein the medium COLORLOK ^® -paper (Hewlett-Packard Co., Houston, Texas, USA). For the comparative dye inkjet print media sample, oleic acid was used as a deinking chemical. 8A and 8B are schematic representations of handsheets were made of non-deinked pulps and deinked pulps of a dye-based inkjet print medium sample, wherein the medium COLORLOK ^® -paper (Hewlett-Packard Co., Houston, Texas, USA). For the dye-inkjet print media sample, erucic acid was used as a deinking chemical. The hand pattern in 7A - 8B were formed from prints made with a cyan, magenta and / or yellow and / or black dye ink containing carbon black nanoparticles.

An alkaline deinking process was performed for the Comparative Dye Inkjet Print Media Sample and for the Dye Inkjet Print Media Sample, respectively. The respective alkaline deinking processes followed the protocol according to method 11p of INGEDE (International Association of the Deinking Industry). The deinking processes were performed with deinking chemicals, including about 0.3 weight percent sodium hydroxide, 0.9 weight percent sodium silicate and 0.7 weight percent hydrogen peroxide. As mentioned above, oleic acid was used as a deinking chemical when converting to pulp of the Comparative Dye Inkjet Print Media Sample and erucic acid as a deinking chemical when converting to pulp Dye inkjet print media sample used. In each of the deinking processes, each of the acids was used in an amount of about 0.8% by weight.

The brightness (Y) of the water in the flotation tank was measured both after conversion to pulp and after conversion to pulp and flotation for both the comparative samples and the samples. This was done by an optical measurement of the filter mat made of the non-depressed pulp and the de-inked pulp using a standard industry process called INGEDE Method 2 (International Association of the Deinking Industry) entitled "Measurement of Optical Characteristics of Pulps and Filtrates from Deinking Processes "(measurement of optical properties of pulps and filtrates from deinking processes). The ink removal (IE) of the comparative deinked sample and the deinked sample was also measured by the same process, method 2 of INGEDE.

A comparison between the comparative sample and the sample was made in terms of ink removal (IE) and brightness difference (ΔY). The results show that the erucic acid-depleted sample had a higher IE (which was about 43.8% removed ink particles) than the oleic acid-depleted comparative sample (where the IE was about 40.3% removed ink particles). Further, in the oleic acid-depleted comparative sample, a significantly greater brightness difference (ΔY) was observed (ie, a ΔY of about 31.7) compared to the erucic acid-depleted sample (ie, a ΔY of about 11.7 lower than the threshold was from 18). Based on these results, it can be concluded that erucic acid is more effective as a deinking chemical for inkjet dye inks than oleic acid. In this sense, it is believed that erucic acid can be incorporated or applied into or onto a paper substrate as an effective deinking agent for the deinking of inkjet dye inks printed on such a paper substrate.

7C respectively. 8C are representations of a membrane filter made with the process water that i) after deinking the comparative dye inkjet print media sample using oleic acid as a deinking chemical; and ii) after deinking the dye inkjet print media sample at the erucic acid was used as a deinking chemical. The membrane filter is representative of the quality of process water remaining after conversion to pulp and flotation in the tank. More specifically, a sample of about one liter containing de-inked pulp was removed from the flotation tank after the flotation cycle was completed. The liquid was then passed through Whatman 41 grade medium pore filter paper using a Buchner filter. Approximately 100 ml of the filtrate from the Buchner filter was collected and completely drained in a vacuum filter unit with a cellulose nitrate membrane filter (ie the membrane filter). The membrane filter was then dried and used as a measure of the dissolved ink in the flotation tank. The darker color shown in the membrane filter (MF) for the comparative pressure sample containing oleic acid ( 7C ), shows that too much paint (ie the presence of ink particles) was left after deinking in the water, so that the water could not be reused for another deinking process. In contrast, the membrane filter for the pressure sample in which erucic acid was used as a deinking chemical was substantially clear (see 8C ) and indicated that the water did not contain as much ink and was reusable.

Example 4

9A and 9B are schematic representations of handsheets of non deinked pulps (ie, those who were not subjected to flotation) or deinked pulps a comparative pigmented inkjet print medium sample were made, wherein the medium COLORLOK ^® -paper (Hewlett-Packard Co., Houston , Texas, USA). For the comparative pigmented inkjet print media sample, oleic acid was used as a deinking chemical. 10A and 10B are schematic representations of handsheets were made of non-deinked pulps and deinked pulps of pigmented inkjet printing media samples, wherein the medium COLORLOK ^® -paper (Hewlett-Packard Co., Houston, Texas, USA). For the pigmented inkjet print media sample, erucic acid was used as a deinking chemical. The hand pattern in 9A - 10B were formed by printing, (Houston, Texas, USA available from Hewlett-Packard Co.) were generated with pigmented inks for HP ^® Edge Line printers.

An alkaline deinking process was carried out for the comparative pigmented inkjet print media sample and for the pigmented inkjet print media sample, respectively. The respective alkaline deinking processes followed the protocol according to method 11p of INGEDE (International Association of the Deinking Industry). The deinking processes were performed with deinking chemicals, including about 0.3 weight percent sodium hydroxide, 0.9 weight percent sodium silicate and 0.7 weight percent hydrogen peroxide. Further, as mentioned above, oleic acid was used as a deinking chemical when converting into pulp of the comparative pigmented inkjet print medium sample, and erucic acid was used as a deinking chemical when converting into pulp of the pigmented inkjet print medium sample. In each of the deinking processes, each of the acids was used in an amount of about 0.8% by weight.

The brightness (Y) of the water in the flotation tank was measured after both converting to pulp and converting to pulp and flotation for both the comparative pigmented inkjet print media sample and the pigmented inkjet print media sample. The brightness (Y) was measured by the method 2 of INGEDE mentioned above. The ink removal (IE) of the comparative deinked sample and the deinked sample was also measured by Method 2 of the INGEDE.

A comparison between the comparative pigmented inkjet print media sample and the pigmented inkjet print media sample was made for ink removal (IE) and brightness difference (ΔY). The results show that the sample deinked with erucic acid as a deinking chemical had higher ink removal (which was about 71.5 removed ink particles) than the comparative sample depleted with oleic acid as a deinking chemical (IE was about 43.4 inches of ink particles removed amounted to). Further, in the oleic acid-depleted comparative pigmented inkjet print media sample, a significantly greater brightness difference (ΔY) was observed (ie, a ΔY of approximately 35) compared to the erucic acid-deinked pigmented inkjet print media sample (ie, a ΔY of approximately 9.9; again lower than the threshold of 18). Based on these results, it can be concluded that erucic acid is more effective than oleic acid as a deinking chemical for pigmented inkjet inks. In this sense, it is believed that erucic acid can be incorporated or applied into or onto a paper substrate as an effective deinking agent for the deinking of pigmented inkjet inks printed on such a paper substrate.

9C respectively. 10C are representations of a membrane filter made with the process water that i) after deinking the comparative pigmented inkjet print media sample using oleic acid as a deinking chemical; and ii) after deinking the pigmented inkjet print media sample for erucic acid as deinking Chemical was used. These membrane filters were formed and treated in the same manner as the membrane filters described in Example 3. The darker color shown in the membrane filter for the comparative pigmented inkjet print media sample depleted with oleic acid ( 9C ), shows that too much paint (ie ink particles) was left in the water after deinking, so that the water could not be reused for another deinking process. In contrast, the membrane filter for the pigmented inkjet print media sample which had been deucrose-scavenged was essentially clear (see 10C ) and indicated that the water did not contain as much ink and was reusable.

Example 5

11A and 11B Figures 12 and 12 are schematic representations of handsheets made from non-depressed pulps (ie, those that were not flotated) and de-inked pulps from coldset comparative offset coldset web offset paper samples where the media was matte coated paper. For this comparative sample, oleic acid was used as a deinking chemical. 12A and 12B are schematic illustrations of handsheets made from non-depressed pulps of dull coldset web offset paper samples, the media being dull coated paper. In this sample, deinking with erucic acid as a deinking chemical was performed. The hand pattern in 11A - 12B were formed from prints using offset inks.

An alkaline deinking process was performed for the comparative coldset coldset web offset print media sample and the matte coldset web offset print media sample. The alkaline deinking processes followed the protocol according to method 11p of INGEDE (International Association of the Deinking Industry). The respective deinking processes were carried out with deinking chemicals, including about 0.3 weight percent sodium hydroxide, 0.9 weight percent sodium silicate and 0.7 weight percent hydrogen peroxide. Further, as mentioned above, oleic acid was used as a deinking chemical when converting into pulp of the Comparative Matt Coldset web offset print media sample, and erucic acid was used as a deinking chemical when converting into pulp of the coldset web offset wet offset print media sample. In each deinking process, each of the acids was present in an amount of about 0.8% by weight.

The results obtained for the comparative matte coldset web offset print media sample and the matte coldset web offset print media sample provide adequate deinkability for offset printing when deinking either oleic acid or erucic acid was used as the deinking chemical. This is both in 11B as well as in 12B for oleic acid and erucic acid deinked samples, respectively.

In Examples 2 to 5 above, it has been found that erucic acid can be used as a suitable deinking chemical in pulp conversion for the removal of LEP inks, dye inks, pigmented inks, and offset inks from various papers. Based on these results, it is believed that the erucic acid also acts in the same way when the fatty acid is applied and / or applied as a deinking agent in and / or on the paper. When incorporated in and / or on paper, erucic acid will be closer to the inks so it is anticipated that the deinking results for these examples may be even better than the deinking results reported herein ,

Example 6

Table 3 shows the results according to the deinking score card of the European Recycling Paper Council for the comparative deinked samples and deinked samples of each of Examples 2-5. The first section of Table 3 presents the parameters of the European Recycling Paper Council's deinking point card; and the following sections of Table 3 represent the points for the various Examples 2-5. Table 3: Results from the European Recycling Paper Council's deinking score card for the comparative samples and samples in Examples 2-5 Parameters of the deinking points card of the European Recycling Paper Council optical brightness, Y Color, a * Dirt, A ₅₀ (mm ² / m ² ) Dirt, A ₂₅₀ (mm ² / m ² ) Ink removal, IE (%) Filtrate darkening, ΔY Total score threshold 47 -3 / + 2 2000 600 40 18 100 aim 90 -2 / + 1 600 180 80 6 Max. score 35 20 15 10 10 10 Comparative examples with oleic acid Example no. optical brightness, Y Color, a * Dirt, A ₅₀ (mm ² / m ² ) Dirt, A ₂₅₀ (mm ² / m ² ) Ink removal, IE (%) Filtrate darkening, ΔY Total score 2 33 20 -15 -10 10 10 Ungen. 3 26 20 15 10 1 -10 Ungen. 4 17 20 15 10 1 -1 Ungen. 5 35 20 15 10 10 10 100 Examples with erucic acid Example no. optical brightness, Y Color, a * Dirt, A ₅₀ (mm ² / m ² ) Dirt, A ₂₅₀ (mm ² / m ² ) Ink removal, IE (%) Filtrate darkening, ΔY Total score 2 35 20 15 10 10 10 100 3 17 20 15 10 1 5 68 4 35 19 15 10 10 7 96 5 35 20 15 10 10 10 100

It should be understood that a total score of 70 on the deinking score card of the European Recycling Paper Council is considered good deinkability.

In Table 3, if any print sample of any category (eg, A ₅₀ , ΔY, etc.) does not do justice (as indicated by the term "unspecified" in the total score of the table), the print sample could be deinked 11p INGEDE is not properly deinked and is considered inappropriate for deinking. As shown in Table 3, deinking for all four of the papers can be achieved with the deinking agent erucic acid in the paper, whereas in Comparative Examples 2-4 the incorporation of oleic acid into the paper was determined by the procedure of 11p INGEDE predetermined standards of existence can not be achieved. In fact, it has been found that of all the comparative examples, only the offset paper (Comparative Example 5) can be properly deinked with the deinking agent oleic acid as a component of the paper.

It should be understood that the ranges provided herein include the specified range and any value or subrange within the specified range. For example, a range of about 0.2% to about 2% by weight is to be interpreted as including not only the explicitly stated limits of from about 0.2% to about 2% by weight, but also individual values such as, for example; B. 0.2 weight percent, 0.7 weight percent, 1 weight percent, etc., and subregions such. From about 0.5 weight percent to about 1 weight percent, from about 0.75 weight percent to about 1.6 weight percent, etc. Furthermore, using "about" to describe a value implies that minor deviations (up to +/- 10%) from the indicated value are included.

While several examples have been described in detail, it will be apparent to those skilled in the art that the disclosed examples may be modified. The foregoing description is therefore intended to be non-limiting.

Claims (15)

A recording medium comprising: a substrate; and a deinking agent, incorporated: i) in the substrate, ii) on the substrate in a layer; or iii) both i and ii, wherein the deinking agent is selected from an unsaturated fatty acid having 19 to 23 carbon atoms and combinations of these unsaturated fatty acids, wherein the deinking agent is intended to interact with an ink which is printed on the recording medium to remove the ink during a deinking process. The recording medium as defined in claim 1, wherein the unsaturated fatty acid has a chemical formula of C ₂₂ H ₄₂ O ₂ , and wherein a double bond of C ₂₂ H ₄₂ O _{2 is located} at any position along its carbon chain. The recording medium as defined in claim 2, wherein the unsaturated fatty acid is erucic acid. The recording medium as defined in claim 1, wherein the unsaturated fatty acid is present in an amount ranging from about 0.2% to about 2% by weight per unit weight of the substrate. The recording medium as defined in claim 1, further comprising another deinking agent selected from a saturated fatty acid, another unsaturated fatty acid and combinations thereof. The recording medium as defined in claim 5, wherein: the saturated fatty acid is selected from acetic, propionic, butyric, valeric, caproic, enanthic, caprylic, pelargonic, capric, undecanoic, lauric, tridecanoic, myristic, pentadecanoic, palmitic, margaric, stearic, Nonadecanoic acid, arachic acid, heneicosanoic acid, behenic acid, tricanoic acid, lignoceric acid, pentacosanoic acid, cerotic acid, heptacosanoic acid, montanic acid, nonacanoic acid, melissic acid, hentriacontanoic acid, lacceric acid, psyllic acid, geddic acid, ceroplastinic acid and hexatriacontanoic acid; and the other unsaturated fatty acid is selected from α-linolenic acid, stearidonic acid, eicosapentaenoic acid, docosahexaenoic acid, linoleic acid, γ-linolenic acid, dihomo-γ-linolenic acid, arachidonic acid, oleic acid, eicosenoic acid, nervonic acid and Mead's acid. The recording medium as defined in claim 1, wherein the recording medium contains the layer in which the deinking agent is incorporated. The recording medium as defined in claim 7, wherein the layer further has another deinking agent therein, wherein the further deinking agent is selected from a saturated fatty acid, another unsaturated fatty acid or combinations thereof. The recording medium as defined in claim 1, wherein the substrate is selected from a base paper containing cellulose fibers. A method of forming the recording medium as defined in claim 1, comprising introducing the deinking agent into the substrate by: Forming a paper base by any chemical or mechanical treatment of wood pulp; and Add the deinking agent to the paper base. A method of forming the recording medium as defined in claim 1, comprising: Adding the deinking agent to a combination of a pigment and a binder to form a coating layer composition; and Applying the coating layer composition to a surface of the substrate to form the layer. Deinking process, comprising: Converting into pulp a medium of which an area is imprinted with an ink in the presence of a deinking chemical to form a slurry, the medium having a deinking agent which: i) is introduced into the medium, ii) in a layer formed on one surface of the medium is introduced; or iii) is both i and ii, the deinking agent being selected from an unsaturated fatty acid having 19 to 23 carbon atoms and combinations of these unsaturated fatty acids; and Perform a flotation process with the slurry and a frother. The deinking process as defined in claim 12, wherein the deinking agent, when interacting with the ink during the process of pulping, breaks up the ink into smaller particles which are removable during the flotation process, and wherein the ink is from liquid electrophotography (Fig. LEP) inks, pigmented inkjet inks, inkjet dye inks and inks for offset printing. The deinking process as defined in claim 12, wherein the medium further contains another deinking agent in combination with the deinking agent, wherein the further deinking agent is selected from a saturated fatty acid, another unsaturated fatty acid, and combinations thereof. The deinking process as defined in claim 12, wherein the deinking chemical is a mixture of sodium hydroxide, sodium silicate and hydrogen peroxide.

Images