Patent Application
20210230806
The invention relates to a water-disintegratable fiber composite material, comprising a number of fiber elements and at least one binding agent, which is formed of or comprises a water-soluble polysaccharide.
Corresponding water-disintegratable fiber composite materials, or fiber products produced therefrom, are essentially known. Corresponding fiber composite materials are required to undergo rapid and full disintegration or rapid and full dispersibility upon contact with water. Corresponding fiber composite materials are therefore to disintegrate or disperse both quickly and fully, to as great an extent as possible, upon contact with water.
To achieve such dispersion properties, various fiber composite materials have been proposed in the prior art, which have low wet strength, that is, a high disintegration or dispersion capability upon contact with water.
At times, the structural properties of corresponding fiber composite materials, that is, in particular the mechanical properties thereof, offer room for improvement. This applies in particular to fiber composite materials having specific fields of application or use that encompass a certain degree of mechanical stress being applied to the fiber composite materials, at least intermittently.
It is the object of the invention to provide a water-disintegratable fiber composite material that is, in particular, improved with respect to the structural properties thereof, that is, in particular, the mechanical properties thereof.
The object is achieved by a water-disintegratable fiber composite material according to claim 1. The associated dependent claims relate to possible embodiments of the water-disintegratable fiber composite material.
The water-disintegratable fiber composite material described herein, referred to hereafter as “fiber composite material” for short, has special properties, which are, in particular, special disintegration properties in water as well as special structural properties, that is, in particular mechanical properties.
The fiber composite material has comparatively low wet strength, that is, comparatively low mechanical strength upon contact with water. The low wet strength enables rapid and full disintegration, or rapid and full dispersion, of the fiber composite material into individual fiber elements upon contact with water. After being introduced in water, the fiber composite material disintegrates or the fiber composite material disperses very quickly as a result of the low wet strength thereof, or the high disintegratability or dispersibility thereof, so that clogging of a waste water system after disposal of the fiber composite material, for example in drains, toilets, and the like, is avoided, or the fiber composite material does not have to be removed separately at the sewage treatment plant prior to the actual purification process of the waste water. The fiber composite material thus enables (substantially) complete disintegration upon contact with water, that is, in particular after being introduced in water. After being introduced in water, the fiber composite material typically disintegrates or disperses within less than 1 hour, preferably within less than 15 minutes, more preferably within less than 1 minute, more preferably within less than 30 seconds, and more preferably within less than 10 seconds. As mentioned, individual fiber elements are present after disintegration, which are no longer bound to one another and, in particular due to a comparatively short fiber length, also can no longer be bound to one another in dispersion, whereby, for example, deposits, clumping or clogging in/of waste water systems can be avoided. The fiber length, as will be apparent hereafter, is typically so short that it is not possible for the fiber elements to become entwined in a (turbulent) flow field, for example of a waste water system.
The low wet strength as well as the generally favorable biodegradability and bioavailability of the fiber composite material results in rapid and full disintegration, up to and including complete metabolic degradation, of the fiber composite material, even if (inadvertently) released into nature and the environment.
The term “wet strength” shall be understood to mean the strength of the fiber composite material upon contact with water, or in the presence of an excess of water. The wet strength can be determined, for example, by way of a wet tensile test according to DIN EN ISO 12625, Part 5 (publication date: 2005-09) “Determination of wet tensile strength.”
The fiber composite material preferably has wet strength, determined by way of the wet tensile test according to DIN EN ISO 12625 at 20° C. and relative humidity of 65%, of no more than 2 N, preferably of no more than 1 N, and more preferably of no more than 0.5 N. In particular, the fiber composite material has wet strength of no more than 2 N, preferably no more than 1 N, and more preferably no more than 0.5 N. This applies in particular to moisture strength of more than 3 N, preferably in a range between 3 N and 250 N, more preferably in a range between 6 N and 210 N, more preferably in a range between 5 N and 80 N, more preferably in a range between 6 N and 55 N, more preferably in a range between 5 and 20 N. Depending on the requirement profile with regard to a specific end product, exceptions, both upward and downward, are of course conceivable.
In addition to the low wet strength, the fiber composite material thus typically also has comparatively high moisture strength, that is, comparatively high mechanical strength when wet. The fiber composite material thus even has comparatively high mechanical strength when wet if exposed briefly to mechanical stress, for example due to friction with a surface.
The term “moisture strength” shall be understood to mean the strength of the fiber composite material, in particular in water or in the presence of an aqueous liquid comprising at least one organic component. The at least one organic component can, for example, be selected from the group consisting of aliphatic alcohols, aliphatic ethers, aliphatic esters, monosaccharides, oligosaccharides, and mixtures or combinations thereof. The moisture strength can be ascertained, for example, by way of a tensile test using the strip method according to DIN EN ISO 13934-1 (publication date: 1999-04).
The fiber composite material preferably has moisture strength, determined by way of the tensile test using the strip method according to DIN EN ISO 13934-1 at 20° C. and relative humidity of 65%, of more than 3 N, in particular in a range between 3 N and 250 N, preferably in a range between 4 N and 150 N, more preferably in a range between 4.5 N and 120 N, more preferably in a range between 5 N and 80 N, and more preferably in a range between 6 N and 55 N. Depending on the requirements profile with respect to a specific end product, exceptions, both upward and downward, are of course conceivable.
The wet strength of the fiber composite material is defined by the composition of the constituents or components forming the fiber composite material, or can be defined in a targeted manner by deliberately varying the composition of the constituents or components forming the fiber composite material. In particular, it is possible to match the wet strength of the fiber composite material to a certain application or use of the fiber composite material, by deliberately varying the composition of the constituents or components forming the fiber composite material. This applies analogously to the moisture strength of the fiber composite material.
The fiber composite material comprises a number or a plurality of fiber elements as well as at least one binding agent as essential constituents or components. Specific embodiments of the fiber elements or of the binding agent, as well as potential further constituents or components of the fiber composite material, are described in more detail below.
The fiber elements are wettable in water or in an aqueous solution. The fiber elements can be swellable upon contact with water. The fiber elements thus can have a certain degree of water absorbency, which results in swelling (increase in volume) of the fiber elements upon contact with water. The fiber elements can form a basic matrix of the fiber composite material or be understood as such.
The fiber elements can be formed of natural, that is animal or plant, or synthetic inorganic and/or organic fibers or fiber materials. The fiber elements are preferably formed of natural organic fibers or fiber materials. It is possible to use fiber elements that are identical chemically and/or geometrically and/or physically and/or that differ chemically and/or geometrically and/or physically. As a result, mixtures of different fiber elements, that is, which differ in at least one chemical, geometric or physical property, may thus also be present. Examples of inorganic fiber elements are basalt, glass, silica, mineral, and carbon fibers. Examples of organic fiber elements are hemp or pulp fibers (cellulose fibers). Examples of synthetic organic fiber elements are polyester, polyamide, polyimide, polyamide-imide, polyethylene, polypropylene, and polyvinyl chloride fibers.
Preferably, primarily natural fiber elements, that is, in particular pulp fibers, are used. Additionally, it is possible, for example, to use rayon, cotton, wool, acetate or Tencel fibers. In a preferred embodiment, the fiber elements comprise 40 to approximately 98 wt. %, and more preferably 60 to 95 wt. % pulp fibers, in each case based on the total weight of the dry fiber composite material. The pulp fibers used can be obtained by way of chemical digestion of plant fibers or by using recycled fibers. It is possible to use both ligneous fibers, fibers from palms or annuals, such as hey, straw, bagasse, kenaf, or bamboo, and mixtures or combinations thereof. Moreover, any wood pulp, that is, both coniferous wood pulp and hardwood pulp, can be used.
The fiber elements preferably have a length of at least 0.1 mm, preferably in a range between 0.1 mm and 10 mm, more preferably in a range between 0.2 and 6 mm, more preferably in a range between 1 mm and 4 mm, and more preferably in a range between 1.1 and 3 mm. The fiber composite material preferably does not comprise any fiber elements that have a fiber length of more than 6 mm. After the fiber composite material has been dissolved in water, the use of accordingly short fiber elements prevents individual or multiple fibers from becoming mechanically joined, that is, for example, becoming tangled, looped, felted or entwined, forming fiber element aggregates, the fiber element aggregates possibly resulting in clogging. As mentioned, the fiber elements thus typically have a fiber length below a concentration-dependent and fiber material-dependent entwining limit. The fiber elements are preferably soluble and/or dispersible in water, regardless of the geometry thereof.
The fiber elements can have a certain fiber geometry, that is, in particular a certain fiber length, which, after the fiber composite material has disintegrated, makes it more difficult or impossible for the fiber elements to become joined to one another. As mentioned, the fiber elements are typically selected to be so short, and in particular these typically have a fiber length of less than 6 mm, that they are unable to mechanically join to one another, formed, for example, by becoming tangled, looped, or entwined, neither in a dry, moist or wet state, nor in a state in which these have disintegrated or dispersed after the fiber composite material has been introduced in water. The fiber elements thus typically have a fiber length below a, possibly fiber element-specific, entwining limit, above which mechanical joining of the fiber elements would be possible, formed, for example, by becoming tangled, looped or entwined. The entwining limit, which can also be referred to or considered as an entwining limit fiber length, shall be understood to mean a concentration-dependent and fiber material-dependent fiber length that, in the flow field, results in the formation of mechanically stable fiber-fiber agglomerates, or fiber-fiber bonds.
The structural cohesion, or the structural or mechanical properties resulting therefrom, that is, in particular the strength of the fiber composite material when dry, moist or wet, is typically established by the binding agent or the hardening process thereof. As a result, only the binding agent is typically used to form or ensure a sufficiently stable bond of the fiber elements, or between the fiber elements, which is typically formed by chemical or physicochemical fixation, that is, in particular the formation of hydrogen bonds, fiber element-fiber element bonds or binding agent films. For this purpose, the fiber elements are, at least in sections, and in particular completely, surrounded by the binding agent or embedded therein, or fixed to one another at contact points and fiber element-fiber element intersecting points (wedge region).
The binding agent is formed of a water-soluble, in particular acid group-containing, polysaccharide, that is, comprising at least one acid group, or comprises at least one such polysaccharide. The water solubility of the polysaccharide means, in particular, that at least 1 g, in particular at least 2 g, preferably at least 5 g is soluble in 100 g distilled water at a temperature of 25° C. and a pressure of 1 atm.
The binding agent, which can be applied, for example, in the form of an aqueous solution and/or a foam, typically has a certain ability to absorb water, which is preserved even after the binding agent has hardened and, upon renewed contact with water, results in swelling (increase in volume) and/or dissolution of the binding agent. The binding agent, as mentioned, is used to bind the fiber elements to one another, for example adhesively or cohesively. For example, the binding agent, after having been applied to the fiber elements and subsequently dried, can adhere to the fiber elements, whereby the fiber elements are bound to one another adhesively or cohesively. As mentioned, the binding agent can be bound to the fiber elements by hydrogen bonds.
What is essential is that the binding agent has a viscosity of more than 500 mPas, measured on an aqueous solution containing 2 wt. % binding agent or in water at 20° C. In particular, the binding agent has a viscosity of (far) more than 500 mPas, measured on an aqueous solution containing 2 wt. % binding agent or in water at 20° C. The viscosity of the binding agent is (was) measured, for example, by way of a rotational viscometer, for example of the type Haake Viscotester VT 550, with a cylinder system, and cup, at a speed of 2.55 s−1.
Again measured on an aqueous solution containing 2 wt. % binding agent or in water at 20° C., the binding agent can have a viscosity in a range of 501 mPas to 3000 mPas, in particular in a range between 520 mPas and 1200 mPas, and preferably in a range between 550 mPas and 900 mPas. Specific conceivable viscosity ranges, again measured on an aqueous solution containing 2 wt. % binding agent or in water at 20° C., are, for example, ranges between 550 mPas and 600 mPas, between 520 and 660 mPas, between 600 and 700 mPas, and between 880 and 1150 mPas.
The binding agent can thus, for example, have a viscosity of more than 550 mPas, preferably more than 600 mPas, more preferably more than 700 mPas, more preferably more than 800 mPas, more preferably more than 900 mPas, more preferably more than 1000 mPas, more preferably more than 1100 mPas, more preferably more than 1200 mPas, more preferably more than 1300 mPas, more preferably more than 1400 mPas, more preferably more than 1500 mPas, more preferably more than 1600 mPas, more preferably more than 1700 mPas, more preferably more than 1800 mPas, more preferably more than 1900 mPas, more preferably more than 2000 mPas, more preferably more than 2100 mPas, more preferably more than 2200 mPas, more preferably more than 2300 mPas, more preferably more than 2400 mPas, more preferably more than 2500 mPas, more preferably more than 2600 mPas, more preferably more than 2700 mPas, more preferably more than 2800 mPas, more preferably more than 2900 mPas, and more preferably more than 3000 mPas, measured on an aqueous solution containing 2 wt. % binding agent at 20° C.
In particular, the binding agent can have a viscosity of more than 510 mPas, in particular more than 520 mPas, preferably more than 530 mPas, more preferably more than 540 mPas, more preferably more than 550 mPas, more preferably more than 560 mPas, more preferably more than 570 mPas, more preferably more than 580 mPas, more preferably more than 590 mPas, more preferably more than 600 mPas, more preferably more than 610 mPas, more preferably more than 620 mPas, more preferably more than 630 mPas, more preferably more than 640 mPas, more preferably more than 650 mPas, more preferably more than 660 mPas, more preferably more than 670 mPas, more preferably more than 680 mPas, more preferably more than 690 mPas, more preferably more than 700 mPas, more preferably more than 710 mPas, more preferably more than 720 mPas, more preferably more than 730 mPas, more preferably more than 740 mPas, more preferably more than 750 mPas, more preferably more than 760 mPas, more preferably more than 770 mPas, more preferably more than 780 mPas, more preferably more than 790 mPas, more preferably more than 800 mPas, more preferably more than 810 mPas, more preferably more than 820 mPas, more preferably more than 830 mPas, more preferably more than 840 mPas, more preferably more than 850 mPas, more preferably more than 860 mPas, more preferably more than 870 mPas, more preferably more than 880 mPas, more preferably more than 890 mPas, more preferably more than 900 mPas, more preferably more than 910 mPas, more preferably more than 920 mPas, more preferably more than 930 mPas, more preferably more than 940 mPas, more preferably more than 950 mPas, more preferably more than 960 mPas, more preferably more than 970 mPas, more preferably more than 980 mPas, more preferably more than 990 mPas, more preferably more than 1000 mPas, more preferably more than 1010 mPas, more preferably more than 1020 mPas, more preferably more than 1030 mPas, more preferably more than 1040 mPas, more preferably more than 1050 mPas, more preferably more than 1060 mPas, more preferably more than 1070 mPas, more preferably more than 1080 mPas, more preferably more than 1090 mPas, more preferably more than 1100 mPas, more preferably more than 1110 mPas, more preferably more than 1120 mPas, more preferably more than 1130 mPas, more preferably more than 1140 mPas, more preferably more than 1150 mPas, more preferably more than 1160 mPas, more preferably more than 1170 mPas, more preferably more than 1180 mPas, more preferably more than 1190 mPas, more preferably more than 1200 mPas, more preferably more than 1210 mPas, more preferably more than 1220 mPas, more preferably more than 1230 mPas, more preferably more than 1240 mPas, more preferably more than 1250 mPas, more preferably more than 1260 mPas, more preferably more than 1270 mPas, more preferably more than 1280 mPas, more preferably more than 1290 mPas, more preferably more than 1300 mPas, more preferably more than 1310 mPas, more preferably more than 1320 mPas, more preferably more than 1330 mPas, more preferably more than 1340 mPas, more preferably more than 1350 mPas, more preferably more than 1360 mPas, more preferably more than 1370 mPas, more preferably more than 1380 mPas, more preferably more than 1390 mPas, more preferably more than 1400 mPas, more preferably more than 1410 mPas, more preferably more than 1420 mPas, more preferably more than 1430 mPas, more preferably more than 1440 mPas, more preferably more than 1450 mPas, more preferably more than 1460 mPas, more preferably more than 1470 mPas, more preferably more than 1480 mPas, more preferably more than 1490 mPas, more preferably more than 1500 mPas, more preferably more than 1510 mPas, more preferably more than 1520 mPas, more preferably more than 1530 mPas, more preferably more than 1540 mPas, more preferably more than 1550 mPas, more preferably more than 1560 mPas, more preferably more than 1570 mPas, more preferably more than 1580 mPas, more preferably more than 1590 mPas, more preferably more than 1600 mPas, more preferably more than 1610 mPas, more preferably more than 1620 mPas, more preferably more than 1630 mPas, more preferably more than 1640 mPas, more preferably more than 1650 mPas, more preferably more than 1660 mPas, more preferably more than 1670 mPas, more preferably more than 1680 mPas, more preferably more than 1690 mPas, more preferably more than 1700 mPas, more preferably more than 1710 mPas, more preferably more than 1720 mPas, more preferably more than 1730 mPas, more preferably more than 1740 mPas, more preferably more than 1750 mPas, more preferably more than 1760 mPas, more preferably more than 1770 mPas, more preferably more than 1780 mPas, more preferably more than 1790 mPas, more preferably more than 1800 mPas, more preferably more than 1810 mPas, more preferably more than 1820 mPas, more preferably more than 1830 mPas, more preferably more than 1840 mPas, more preferably more than 1850 mPas, more preferably more than 1860 mPas, more preferably more than 1870 mPas, more preferably more than 1880 mPas, more preferably more than 1890 mPas, more preferably more than 1900 mPas, more preferably more than 1910 mPas, more preferably more than 1920 mPas, more preferably more than 1930 mPas, more preferably more than 1940 mPas, more preferably more than 1950 mPas, more preferably more than 1960 mPas, more preferably more than 1970 mPas, more preferably more than 1980 mPas, more preferably more than 1990 mPas, more preferably more than 2000 mPas, more preferably more than 2010 mPas, more preferably more than 2020 mPas, more preferably more than 2030 mPas, more preferably more than 2040 mPas, more preferably more than 2050 mPas, more preferably more than 2060 mPas, more preferably more than 2070 mPas, more preferably more than 2080 mPas, more preferably more than 2090 mPas, more preferably more than 2100 mPas, more preferably more than 2110 mPas, more preferably more than 2120 mPas, more preferably more than 2130 mPas, more preferably more than 2140 mPas, more preferably more than 2150 mPas, more preferably more than 2160 mPas, more preferably more than 2170 mPas, more preferably more than 2180 mPas, more preferably more than 2190 mPas, more preferably more than 2200 mPas, more preferably more than 2210 mPas, more preferably more than 2220 mPas, more preferably more than 2230 mPas, more preferably more than 2240 mPas, more preferably more than 2250 mPas, more preferably more than 2260 mPas, more preferably more than 2270 mPas, more preferably more than 2280 mPas, more preferably more than 2290 mPas, more preferably more than 2300 mPas, more preferably more than 2310 mPas, more preferably more than 2320 mPas, more preferably more than 2330 mPas, more preferably more than 2340 mPas, more preferably more than 2350 mPas, more preferably more than 2360 mPas, more preferably more than 2370 mPas, more preferably more than 2380 mPas, more preferably more than 2390 mPas, more preferably more than 2400 mPas, more preferably more than 2410 mPas, more preferably more than 2420 mPas, more preferably more than 2430 mPas, more preferably more than 2440 mPas, more preferably more than 2450 mPas, more preferably more than 2460 mPas, more preferably more than 2470 mPas, more preferably more than 2480 mPas, more preferably more than 2490 mPas, more preferably more than 2500 mPas, more preferably more than 2510 mPas, more preferably more than 2520 mPas, more preferably more than 2530 mPas, more preferably more than 2540 mPas, more preferably more than 2550 mPas, more preferably more than 2560 mPas, more preferably more than 2570 mPas, more preferably more than 2580 mPas, more preferably more than 2590 mPas, more preferably more than 2600 mPas, more preferably more than 2610 mPas, more preferably more than 2620 mPas, more preferably more than 2630 mPas, more preferably more than 2640 mPas, more preferably more than 2650 mPas, more preferably more than 2660 mPas, more preferably more than 2670 mPas, more preferably more than 2680 mPas, more preferably more than 2690 mPas, more preferably more than 2700 mPas, more preferably more than 2710 mPas, more preferably more than 2720 mPas, more preferably more than 2730 mPas, more preferably more than 2740 mPas, more preferably more than 2750 mPas, more preferably more than 2760 mPas, more preferably more than 2770 mPas, more preferably more than 2780 mPas, more preferably more than 2790 mPas, more preferably more than 2800 mPas, more preferably more than 2810 mPas, more preferably more than 2820 mPas, more preferably more than 2830 mPas, more preferably more than 2840 mPas, more preferably more than 2850 mPas, more preferably more than 2860 mPas, more preferably more than 2870 mPas, more preferably more than 2880 mPas, more preferably more than 2890 mPas, more preferably more than 2900 mPas, more preferably more than 2910 mPas, more preferably more than 2920 mPas, more preferably more than 2930 mPas, more preferably more than 2940 mPas, more preferably more than 2950 mPas, more preferably more than 2960 mPas, more preferably more than 2970 mPas, more preferably more than 2980 mPas, more preferably more than 2990 mPas, and more preferably more than 3000 mPas, measured on an aqueous solution containing 2 wt. % binding agent at 20° C.
Each of the aforementioned viscosity values can also be understood or used as limit values for certain viscosity ranges.
In any case, the binding agent thus has a comparatively high viscosity. The comparatively high viscosity of the binding agent is typically linked to a comparatively high molar mass of the binding agent or of the binding agent molecules. The binding agent thus typically has a comparatively high molar mass. The molar mass of the binding agent can, for example, be in a range between 50,000 g/mol and 400,000 g/mol, in particular in a range between 100,000 g/mol and 350,000 g/mol, and preferably in a range between 150,000 g/mol and 300,000 g/mol.
The binding agent can thus, for example, have a molar mass of more than 50,000 g/mol, in particular more than 75,000 g/mol, in particular more than 100,000 g/mol, in particular more than 125,000 g/mol, in particular more than 150,000 g/mol, in particular more than 175,000 g/mol, in particular more than 200,000 g/mol, in particular more than 225,000 g/mol, in particular more than 250,000 g/mol, in particular more than 275,000 g/mol, in particular more than 300,000 g/mol, in particular more than 325,000 g/mol, in particular more than 350,000 g/mol, in particular more than 375,000 g/mol, and in particular more than 400,000 g/mol.
The comparatively high viscosity of the binding agent surprisingly results in special structural properties, that is, in particular in special mechanical properties, of the fiber composite material. In contrast to known fiber composite materials, which have a viscosity of the binding agent, in some instances, of considerably less than 500 mPas, measured on an aqueous solution containing 2 wt. % binding agent at 20° C., the composition of the fiber composite material described herein is thus based on the finding that, surprisingly, especially higher viscosities of the binding agent result in considerably improved structural or mechanical properties of the fiber composite material. The special structural or mechanical properties of the fiber composite material result, in particular, in comparatively high ultimate tensile strength (dry) or in a comparatively high tear value (dry).
In particular due to the comparatively high viscosity of the binding agent, overall a fiber composite material is obtained which is improved with respect to the structural or mechanical properties thereof. The fiber composite material is thus suitable, in particular, for fields of application or uses that encompass a certain degree of mechanical stress being applied to the fiber composite material, at least intermittently.
The weight fraction of the binding agent can thus be 0.5 to 50 wt. %, based on the dry weight or the total dry weight of the fiber composite material. The weight fraction of the binding agent, based on the dry weight or the total dry weight of the fiber composite material, is typically in a range between 1 and 20 wt. %, in particular in a range between 2 and 17 wt. %, and preferably in a range between 3 and 15 wt. %.
As mentioned, the special structural or mechanical properties of the fiber composite material result, in particular, in comparatively high ultimate tensile strength (dry) or in a comparatively high tear value (dry) of the fiber composite material. For example, the fiber composite material can have a tear value (dry) of at least 30 N, preferably at least 35 N, more preferably at least 40 N, more preferably at least 45 N, more preferably at least 50 N, more preferably at least 55 N, more preferably at least 60 N, more preferably at least 65 N, more preferably at least 70 N, more preferably at least 75 N, more preferably at least 80 N, more preferably at least 90 N, and more preferably at least 100 N. The tear values can in particular range between 45 and 60 N. The tear values are measured in each case in the dry state in the longitudinal direction. The tear values (dry) can be ascertained according to DIN EN ISO 1924-2, for example.
As mentioned, the binding agent is a water-soluble polysaccharide, or the binding agent comprises such as polysaccharide. The water-soluble polysaccharide typically includes at least one acid group-containing or carboxyl group-containing moiety. The water-soluble polysaccharide can, for example, be selected from the group consisting of: carboxymethyl cellulose (CMC), carboxymethyl starch (CMS), carboxyethyl cellulose (CEC), carboxypropyl cellulose, carboxymethyl methyl cellulose (CMMC), carboxymethyl ethyl cellulose, carboxymethyl propyl cellulose, carboxyethyl methyl cellulose, carboxyethyl ethyl cellulose, carboxymethyl hydroxymethyl cellulose, carboxymethyl hydroxyethyl cellulose (CMHEC), carboxymethyl hydroxypropyl cellulose, carboxyethyl hydroxymethyl cellulose, carboxyethyl hydroxyethyl cellulose, and mixtures or combinations thereof.
The binding agent can also be formed of water-soluble starch, that is, in particular of water-soluble starch kinds or types other than those mentioned above.
Suitable commercially available binding agents are, for example, the sodium carboxymethyl celluloses Rheolon® 30, Rheolon® 30N, Rheolon® 100N or Rheolon® 300, Rheolon® 300N, Rheolon® 500G and Rheolon® 1000G, each available from Ugur Seluloz Kimya (Aydin, TR), for example. Further suitable commercially available binding agents are, for example, the carboxymethyl celluloses of the types Calexis® and Finnfix®, which are each available, for example, from CP Kelco Germany GmbH (Grossenbrode, DE).
In addition to the fiber elements and the binding agent, the fiber composite material can also contain or comprise at least one dampening solution, that is, in particular an organic dampening solution. The dampening solution can in particular be selected from the group consisting of: aliphatic alcohols, aliphatic ethers, aliphatic esters, or mixtures of at least one aliphatic alcohol and/or at least one aliphatic ether and/or at least one aliphatic ester. In particular, ethanol, propanol, ethane-1,2-diol, propane-1,2-diol, propane-1,3-diol, 1,2,3-propanetriol, and mixtures or combinations may be used. The dampening solution can thus contain at least one readily volatile organic constituent, that is, for example, ethanol, and/or also at least one hardly volatile organic constituent, in particular a monomeric, oligomeric or polymeric diol or polyol compound, that is, for example, propylene glycol.
The weight fraction of the dampening solution can be 1 to 90 wt. %, in particular below 50 wt. %, preferably below 35 wt. %, more preferably below 20 wt. %, and particularly preferably below 10 wt. %, based on the weight or total weight of the fiber composite material. The fraction of the dampening solution is typically in a range between 30 and 70 wt. %, in particular in a range between 35 and 65 wt. %, and preferably in a range between 40 and 60 wt. %.
The dampening solution or the fiber composite material can have disinfecting properties, in particular when it comprises alcoholic constituents, such as ethanol and/or propanol, in particular mixtures of ethanol and 1-propanol and 2-propanol. The fiber composite material is thus in particular suitable for use as a disinfecting or cleaning tissue.
The dampening solution or the fiber composite material can furthermore have bactericidal and/or bacteriostatic or fungicidal and/or fungistatic properties, in particular when it comprises alcoholic constituents. Bactericidal and/or bacteriostatic or fungicidal and/or fungistatic properties can be expedient for certain fields of application of the fiber composite material.
The fiber composite material can additionally contain or comprise an organic amphoteric component. The organic amphoteric component is typically water-soluble. The amphoteric organic component, which is in particular, as will be apparent hereafter, an amphoteric amine or amine salt, can serve both as an acceptor and as a donor for protons, that is, both as a Brønsted acid and as a Brønsted base. The amphoteric organic component, in combination with the binding agent, can in particular be used to form a (structure-forming) polysalt and/or a polymeric aggregate, which together with the dampening solution, if present, is non-soluble or non-dispersible.
The organic amphoteric component can, as mentioned, in particular be an amphoteric amine or amine salt. The organic amphoteric component is not a surfactant, that is, in particular not an amphoteric surfactant. The organic amphoteric component is thus not a surfactant, that is, in particular not an amine-based or amine salt-based surfactant. Typically, (also) quaternary or long-chain, high molecular weight amphoteric amines are not suitable organic amphoteric components, since these have a dispersing or structure-destroying effect when used as plasticizers and/or having a permanent cationic charge, and impair or prevent the moisture strength of the fiber composite material.
A corresponding amine suitable for use as an amphoteric organic component for the fiber composite material can be a, preferably water-soluble, aminocarboxylic acid, preferably alpha-aminocarboxylic acid, which is preferably selected from the group consisting of: alanine, arginine, asparagine, aspartic acid, citrulline, cysteine, S-methylcysteine, cystine, creatine, homocysteine, homoserine, norleucine, 2-aminobutanoic acid, 2-amino-3-mercapto-3-methylbutanoic acid, 3-aminobutanoic acid, 2-amino-3,3-dimethylbutanoic acid, 4-aminobutanoic acid, 2-amino-2-methylpropanoic acid, 2-amino-3-cyclohexylpropanoic acid, 3-aminopropanoic acid, 2,3-diaminopropanoic acid, 3-aminohexanoic acid, gamma-carboxyglutamic acid (3-aminopropane-1,1,3-tricarboxylic acid), glutamine, glutamic acid, glycine, histidine, hydroxyproline, p-hydroxyphenylglycine, isoleucine, isovaline, leucine, lysine, methionine, ornithine ((S)-(+)-2,5-diaminopentanoic acid), phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, salts thereof, complexes thereof and mixtures or combinations thereof, preferably of alanine, arginine, glycine, proline, lysine, histidine, glutamine, glutamic acid, aspartic acid, ornithine, salts thereof, complexes thereof, and mixtures or combinations thereof, more preferably of alanine, arginine, glycine, proline, lysine, ornithine, salts thereof, complexes thereof, and mixtures or combinations thereof, more preferably arginine, lysine, ornithine, salts thereof, complexes thereof, and mixtures or combinations thereof, more preferably alanine, glycine, proline, salts thereof, complexes thereof, and mixtures or combinations thereof, more preferably histidine, glutamine, glutamic acid, aspartic acid, salts thereof, complexes thereof, and mixtures or combinations thereof.
Furthermore, short-chain peptides, that is, for example, dipeptides, tripeptides, up to oligomeric peptides or oligopeptides having up to eight amino acid building blocks, consisting of one or different amino acids, can serve as the amphoteric organic component and can thus be used.
Furthermore, all, in particular low molecular weight, non-physiological amines or amino acids as well as the derivatives thereof can serve as the amphoteric organic component and can thus be used.
If present, the amphoteric component preferably comprises at least one protonatable and/or protonated amino group, and furthermore at least one deprotonable and/or deprotonated acid group, more preferably carboxyl group. The protonatable and/or protonated amino group is preferably selected from the group consisting of: primary amino group, secondary amino group, and combinations thereof. An amphoteric amine is preferably an aminocarboxylic acid and/or a salt and/or a complex thereof, and more preferably an alpha-amino acid and/or a salt and/or a complex thereof.
A salt of an amphoteric amine is in particular a salt of a polyvalent metal cation, advantageously having a uniform spherical charge distribution on the surface, that is, preferably Ca2+ and/or Zn2+.
A complex of an amphoteric amine is in particular a complex of a polyvalent metal cation, preferably Ca2+ and/or Zn2+. More preferably, an amphoteric amine comprises a first, preferably protonatable and/or protonated, amino group and a first acid group, preferably a carboxyl group, and optionally furthermore a second, preferably protonatable and/or protonated, amino group and/or a second acid group, preferably a carboxyl group. An amphoteric amine preferably does not comprise any permanently positively charged nitrogen atoms, and more preferably no quaternary ammonium group, such as a tetraalkylammonium group.
The fiber composite material can thus in particular comprise polyvalent metal cations or in particular polyvalent metal cation salts for forming complexes with further constituents of the fiber composite material, in particular with the binding agent and/or with a or the amphoteric organic component, if present. Corresponding metal cations or metal cation salts can in particular be water structure-forming and/or hygroscopically and/or osmotically active or effective. Examples of corresponding salts can be organic salts based on low molecular weight organic acids or amino acids including polyvalent metal cations, for example calcium ions, magnesium ions, zinc ions, and/or inorganic metal cation salts, for example calcium chloride, zinc chloride, in general preferably strongly hygroscopic metal cations or metal cation salts, as well as mixtures of different metal cations or metal cation salts. The weight fraction of corresponding metal cations or metal cation salts is in particular between 0.01 and 20 wt. %, preferably between 0.1 and 10 wt. %, more preferably between 0.2 and 8 wt. %, and particularly preferably between 0.3 and 5 wt. %.
Preferably, suitable polyvalent metal cations are selected from the group consisting of polyvalent, that is, in particular bivalent or trivalent, ions of the transition metals, polyvalent ions of the metals from groups 3A and 4A of the periodic table of the elements, ions of the alkaline earth metals, ions of the transition metals, and mixtures or combinations thereof. Furthermore or accordingly, suitable polyvalent metal cations can be selected from the group consisting of Al3+, Mg2+, Co2+, Fe2+, Fe3+, Ca2+, Mn2+, Ni2+, Zn2+, and mixtures or combinations thereof, in particular preferably Ca2+, Zn2+, and mixtures or combinations thereof.
Suitable metal cations can be introduced into the, preferably aqueous, solution, and preferably lotion, for example, in the form of water-soluble salts and/or complexes of the corresponding metal cations, preferably in the form of hydrogen carbonate, chloride, acetate, lactate, tartrate, fumarate, in the form of carboxylate and/or a complex of any of the above-mentioned aminocarboxylic acids or a mixture thereof, preferably in the form of chloride, carboxylate and/or a complex of any of the above-mentioned aminocarboxylic acids or a mixture thereof, of the corresponding metal cations.
Suitable amphoteric amines are preferably selected from the group consisting of aminocarboxylic acids, which can be unsubstituted or substituted, salts thereof, complexes thereof, and mixtures or combinations thereof. Suitable aminocarboxylic acids, which can be unsubstituted or substituted, are organic compounds that preferably comprise at least one carboxyl group and at least one amino group. As mentioned, suitable amphoteric amines are not surfactants, that is, in particular not amphoteric surfactants.
Suitable aminocarboxylic acids are preferably selected from the group consisting of alanine, arginine, asparagine, aspartic acid, citrulline, cysteine, S-methylcysteine, cystine, creatine, homocysteine, homoserine, norleucine, 2-aminobutanoic acid, 2-amino-3-mercapto-3-methylbutanoic acid, 3-aminobutanoic acid, 2-amino-3,3-dimethylbutanoic acid, 4-aminobutanoic acid, 2-amino-2-methylpropanoic acid, 2-amino-3-cyclohexylpropanoic acid, 3-aminopropanoic acid, 2,3-diaminopropanoic acid, 3-aminohexanoic acid, gamma-carboxyglutamic acid (3-aminopropane-1,1,3-tricarboxylic acid), glutamine, glutamic acid, glycine, histidine, hydroxyproline, p-hydroxyphenylglycine, isoleucine, isovaline, leucine, lysine, methionine, ornithine ((S)-(+)-2,5 diaminopentanoic acid), phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, salts thereof, complexes thereof and mixtures or combinations thereof, preferably alanine, arginine, glycine, proline, lysine, histidine, glutamine, glutamic acid, aspartic acid, ornithine, salts thereof, complexes thereof, and mixtures or combinations thereof, more preferably of alanine, arginine, glycine, proline, lysine, ornithine, salts thereof, complexes thereof, and mixtures or combinations thereof, more preferably arginine, lysine, ornithine, salts thereof, complexes thereof, and mixtures or combinations thereof, more preferably alanine, glycine, proline, salts thereof, complexes thereof, and mixtures or combinations thereof, more preferably histidine, glutamine, glutamic acid, aspartic acid, salts thereof, complexes thereof, and mixtures or combinations thereof.
In a further preferred embodiment, the one amphoteric amine is selected from the group consisting of the aforementioned peptides, consisting of one or different amino acids of those listed directly above.
Metal cations, preferably polyvalent metal cations, can form salts and/or complexes with one of the aforementioned aminocarboxylic acids. More preferably, aforementioned amphoteric amines, and preferably aforementioned aminocarboxylic acids, can be used as salts and/or complexes of polyvalent metal cations, preferably Ca2+ and/or Zn2+.
As mentioned, a corresponding amphoteric amine, preferably the at least one aminocarboxylic acid, which can be unsubstituted or substituted, and/or a salt thereof and/or a complex thereof, can form a polysalt with an acid group-containing moiety, preferably carboxyl group-containing moiety, of the binding agent or polysaccharide, after having been applied to the fiber elements.
As was likewise mentioned, the control of the wet strength of the fiber composite material, that is, the dispersibility of the fiber composite material in water, can be improved by using at least one organic amphoteric component, that is, in particular an amphoteric amine, preferably at least one aminocarboxylic acid, and/or a salt thereof and/or a complex thereof. In particular, the moisture strength of the fiber composite material can also be positively influenced through the aforementioned formation of salts or complexes or polysalts of organic amphoteric components, that is, in particular aminocarboxylic acids, and metal cations.
A weight fraction of a corresponding amphoteric amine, which is preferably selected from the group of aforementioned aminocarboxylic acids, which can be unsubstituted or substituted, salts thereof, complexes thereof, and mixtures or combinations thereof, is preferably in a range between 0.1 wt. % and 30 wt. %, preferably in a range between 0.5 wt. % and 20 wt. %, more preferably in a range between 0.7 weights and 17 wt. %, more preferably in a range between 2 wt. % and 15 wt. %, and more preferably in a range between 3.3 wt. % and 13 wt. %, in each case based on the weight or total weight of the dry fiber composite material.
Even though embodiments according to which the fiber composite material contains or comprises at least one amphoteric organic component are conceivable, it is expressly also conceivable that the fiber composite material does not contain or comprise a (single) amphoteric organic component.
The fiber composite material is in particular suitable for use as a disinfecting or cleaning tissue. The fiber composite material can thus in particular be designed as a disinfecting or cleaning tissue. It must be noted in the process that the special wet strength is to be considered as an indicator action for the (instantaneous) disinfecting or cleaning action of the fiber composite material, since the disinfecting or cleaning action of the fiber composite material decreases when the fiber composite material disintegrates. The disintegration of the fiber composite material is thus typically accompanied by a decrease in the disinfecting or cleaning action of the fiber composite material.
In addition to the use as a disinfecting or cleaning tissue, the fiber composite material is also suitable, for example, for use as a water-disintegratable sanitary tissue, in particular as a moisture-resistant, water-disintegratable cosmetic tissue, or water-disintegratable toilet tissue, and the fiber composite material can thus be designed as water-disintegratable sanitary tissue, in particular as water-disintegratable cleaning tissue or as water-disintegratable toilet tissue.
In addition to the fiber elements and the binding agent, the fiber composite material can, of course, also contain water, that is, have a water fraction. The water fraction thus results from the fractions of the fiber elements, the binding agent, and possibly remaining (optional) constituents, such as the dampening solution and the organic amphoteric component, of the fiber composite material. The water fraction typically represents the remainder, so that the respective constituents of the fiber composite material add up to 100%.
The fiber composite material can have a one-ply or multi-ply design.
In addition to the fiber composite material, the invention also relates to a method for producing a water-disintegratable fiber composite material, in particular a fiber composite material as described herein. The method comprises the following steps:
All embodiments in connection with the fiber composite material apply analogously to the method, and vice versa.
The fiber elements can be provided or be present in the manner or in the form of a nonwoven. The fiber elements to be provided or present can be converted into a fibrous web, for example by way of carding, wet laying, air laying, spun bonding or melt blowing, and can be present in the form of a fiber element web. The fiber element web can be formed using the air laying process, which is also referred to as air forming process and in which the fiber elements are tightly intermingled. The air-laid fiber elements can subsequently be compressed or compacted.
As a result, the following embodiment of the method is conceivable, which, in particular in connection with the provision or production of the fiber elements, comprises the following steps:
The fiber composite material, which can be provided or be present in the form of a nonwoven fabric or nonwoven material, is produced by way of a method, comprising the additional following steps:
(a1) providing fiber elements;
(a2) depositing the fiber elements on a receiving surface, yielding a fiber element web;
(a3) compacting or compressing the fiber element web, yielding a compacted or compressed fiber element web.
In particular, the binding agent and the organic amphoteric component, if present, are applied in step (a1) and/or during steps (a2) and/or (a3) consecutively, together or simultaneously in the form of an aqueous solution and/or in the form of a foam, and thereafter are compacted at a temperature greater than 100° C., preferably greater than 120° C., and preferably greater than 150° C. Thereafter, the dampening solution, if present, can be applied. In an alternative embodiment, the binding agent, the organic amphoteric component, if present, and the dampening solution, if present, are applied in or after step (a3).
The application of the binding agent, the optional organic amphoteric component, and the optional dampening solution preferably each take place independently of one another by way of foulard application, foam application, and/or spraying. The binding agent, the optional organic amphoteric component, and the optional dampening solution can be applied separately from one another to the same side, or to different sides, of the fiber elements or of the fiber composite material. The application of the binding agent, of the optional organic amphoteric component, and of the optional dampening solution can take place simultaneously or not simultaneously (sequentially), wherein the order of application can be varied.
The compaction or compression carried out in step (a3) can be carried out by different, simultaneous or chronologically staggered methods, that is, for example divided into pre- and post-compaction or -compression, such as calendaring, rolling, embossing. By compacting or compressing the fiber composite material, the thickness and/or density of the fiber composite material can be set.
If not already implemented in step (a3), a step (a4) following step (a3) can be carried out for forming a three-dimensional structuring or surface structuring of the fiber composite material, for example by embossing the fiber composite material. In this way, it is possible to form depressions and/or elevations in a targeted manner in the fiber composite material.
The invention is described based on an exemplary embodiment in the drawing. The FIGURE shows a representative illustration of a fiber composite material according to one exemplary embodiment.
The FIGURE shows a representative illustration of a single-ply or multi-ply water-disintegratable fiber composite material 1 according to one exemplary embodiment.
The fiber composite material 1, on the one hand, has comparatively high moisture strength, that is, comparatively high mechanical strength when wet, and, on the other hand, comparatively low wet strength, that is, comparatively low mechanical strength upon contact with water. The comparatively low wet strength allows the fiber composite material 1 to disperse quickly and fully into individual fiber elements 2 upon contact with water. The fiber composite material 1 thus has sufficiently high mechanical moisture strength if exposed briefly to mechanical stress, for example due to friction with a surface. After being introduced in water, the fiber composite material 1 has sufficiently low wet strength or high dispersibility, so that clogging in a waste water system is avoided after disposal of the fiber composite material 1. The fiber composite material 1 is thus in particular suitable for use as a water-disintegratable disinfecting or cleaning tissue. A use as water-disintegratable sanitary tissue, water-disintegratable cosmetic tissue, or as water-disintegratable toilet tissue is also conceivable.
The fiber composite material 1 comprises a number of fiber elements 2, that is, for example, pulp fibers, and a binding agent 3 surrounding the fiber elements 2, which is formed of or comprises a water-soluble polysaccharide. The water-soluble polysaccharide can be carboxymethyl cellulose (CMC), for example.
The binding agent 3 has a viscosity of more than 500 mPas, measured on an aqueous solution containing 2 wt. % binding agent or in water at 20° C. The viscosity of the binding agent 3 is (was) measured, for example, by way of a rotational viscometer, for example of the type Haake Viscotester VT 550, with a cylinder system, and cup, at a speed of 2.55 s−1.
The high viscosity of the binding agent 3 yields special structural properties, that is, in particular special mechanical properties, of the fiber composite material 1, which in particular result in a high tear value (dry).
The table below, by way of example, shows possible compositions of the fiber composite material 1, that is, in particular different binding agents #1 to #4, and related tear values (dry) averaged in each case from six measured values.
Binding agent #1 is a carboxymethyl cellulose of the type Rheolon® 1000 G, binding agent #2 is a carboxymethyl cellulose of the type Calexis®, binding agent #3 is a carboxymethyl cellulose of the type Rheolon® 500 G, and binding agent #4 is a carboxymethyl cellulose of the type Finnfix®.
The viscosity of the binding agent 3 is (was) measured by way of a rotational viscometer of the type Haake Viscotester VT 550, with a cylinder system, and cup, at a speed of 2.55 s−1.
The tear values were measured on dry sample bodies having a width of 50 mm and a length of 100 mm in the longitudinal direction.
The fiber composite material 1 can be produced by a method comprising the following steps:
providing a number of fiber elements 2, in particular in the form of a fiber element web containing the fiber elements;
applying at least one binding agent 3 to the fiber elements 2, in particular to the fiber element web which is formed of or comprises an acid group-containing polysaccharide, wherein the at least one binding agent 3 has a viscosity of more than 500 mPas, measured on an aqueous solution containing 2 wt. % binding agent 3 at 20° C.
| Number | Date | Country | Kind |
|---|---|---|---|
| 18174929.2 | May 2018 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2019/063447 | 5/24/2019 | WO | 00 |
