DE102012109242A1 - Material web useful as a suction pad, comprises a bonded fibrous web made of cellulose, comprising a layer of cellulose fibers which are regionally pressed with each other, and at least one quaternary ammonium compound as an additive - Google Patents

Abstract

Material web comprises a bonded fibrous web (1) made of cellulose, comprising a layer of cellulose fibers (2) which are regionally pressed with each other, and at least one quaternary ammonium compound (3) as an additive.

Description

The present invention relates to a material web with a fibrous web based on pulp, which contains as additives quaternary ammonium compound.

Multi-layered suction mats are widely used in the food industry and also in the hygiene sector. For example, in food packaging they are used as packaging inserts to contain liquid leaking from meat products. Absorbent hygienic articles in the field of hygiene and medicine include changing table covers, hospital pads, head and shoe protection pads and the like. These articles have in common that they are able to absorb and bind liquid.

The known from the prior art absorbent mats are equipped differently depending on the application and contain in addition to the sheet-like base materials nor additives that have to fulfill different tasks, such as to bind the liquid or the absorbent mat to give special properties such as antibacterial properties.

An essential task of these absorbent mats is to absorb and bind fluid. The uptake of the liquid should take place quickly and a backflow of this liquid absorbed in the direction of fluid-emitting body be avoided. The disadvantage is that the absorbent mats can contain several, different aggregates, which should affect their properties. The addition of several additives is both expensive to manufacture and may also cause problems in disposal.

It is an object of the present invention to positively change the absorption behavior of a absorbent mat without negatively influencing the behavior / properties of the absorbent mat in another area.

The subject of the present invention is accordingly a material web in the form of a fibrous web of pulp, consisting of a layer of cellulose fibers which are pressed together in some areas, which is characterized in that quaternary ammonium compounds are contained as aggregate (s).

Surprisingly, it has been found that the rate at which liquids are taken up by a web of pulp can be positively influenced when the web is equipped with quaternary ammonium compounds. The use of quaternary ammonium compounds also has the additional advantage that they have an antimicrobial effect. With the addition of quaternary ammonium compounds, the properties of a material web which is used as a suction mat are therefore positively influenced in two ways.

worin
R¹ und R² unabhängig voneinander ausgewählt sind aus linearen oder verzweigten (C₁-C₆)-Kohlenwasserstoffketten,
x von 0 bis 1 bedeutet,
R⁴ ausgewählt ist aus einer direkten Bindung oder einer linearen oder verzweigten (C₁-C₆)-Kohlenwasserstoffkette,
R⁵ ausgewählt ist aus Wasserstoff oder einer linearen oder verzweigten (C₁-C₆)-Kohlenwasserstoffkette,
R⁶ ausgewählt ist aus einer direkten Bindung und einer linearen oder verzweigten (C₁-C₆)-Kohlenwasserstoffkette, und
Ar⁷ eine N-haltige heteroaromatische Gruppe ist, und
worin die Polymervorstufe derart modifiziert ist, dass mindestens ein Teil der N-Atome substituiert sind mit einem Substituenten ausgewählt aus der Gruppe bestehend aus linearen oder verzweigten (C₁-C₂₀)-Alkylen, und mindestens ein Teil der N-Atome in dieser Polymervorstufe quartärniert sind,

worin
R² eine Alkylengruppe mit 3 bis 10 Kohlenstoffen bedeutet,
R⁴ eine Heteroalkylengruppe mit 2 bis 6 Kohlenstoffatomen und
A^– ein Anion bedeuten und
R¹⁰, R¹¹, R¹² und R¹³ jeweils unabhängig voneinander eine Alkylgruppe mit 1 bis 4 Kohlenstoffatomen, eine Hydroxialkylgruppe mit 1 bis 4 Kohlenstoffatomen oder eine Alkenylgruppe mit 2 bis 4 Kohlenstoffatomen bedeuten;
und/oder Verbindungen mit der Formel V

worin
R¹⁴ eine C₁-C₃₀-Alkylgruppe, vorzugsweise eine C₈-C₃₀-Alkylgruppe ist,
R¹⁵, R¹⁷ und R¹⁸ jeweils unabhängig voneinander eine C₁-C₃₀-Alkylgruppe oder Wasserstoff bedeuten und
R¹⁶ für eine C₁-C₃₀-Alkylengruppe steht, und
X ein Gegenion ist wie Cl^–, Br^–, I^– oder CH₃COO^–.The quaternary ammonium compounds are preferably selected from oligomeric and polymeric quaternary ammonium compounds. Examples of suitable quaternary ammonium compounds are compounds having the following formulas:

wherein
R ¹ and R ^{2 are} independently selected from linear or branched (C ₁ -C ₆ ) -hydrocarbon chains,
x from 0 to 1 means
R ^{4 is} selected from a direct bond or a linear or branched (C ₁ -C ₆ ) -hydrocarbon chain,
R ^{5 is} selected from hydrogen or a linear or branched (C ₁ -C ₆ ) -hydrocarbon chain,
R ^{6 is} selected from a direct bond and a linear or branched (C ₁ -C ₆ ) hydrocarbon chain, and
Ar ^{7 is} an N-containing heteroaromatic group, and
wherein the polymer precursor is modified such that at least a portion of the N atoms are substituted with a substituent selected from the group consisting of linear or branched (C ₁ -C ₂₀ ) alkylene, and at least a portion of the N atoms in this polymer precursor are quaternary,

wherein
R ^{2 represents} an alkylene group of 3 to 10 carbons,
R ^{4 is} a heteroalkylene group having 2 to 6 carbon atoms and
A ^- mean an anion and
R ¹⁰ , R ¹¹ , R ¹² and R ¹³ each independently represent an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms;
and / or compounds of the formula V

wherein
R ^{14 is} a C ₁ -C ₃₀ -alkyl group, preferably a C ₈ -C ₃₀ -alkyl group,
R ¹⁵ , R ¹⁷ and R ¹⁸ each independently represent a C ₁ -C ₃₀ alkyl group or hydrogen, and
R ^{16 is} a C ₁ -C ₃₀ alkylene group, and
X is a counterion such as Cl ^- , Br ^- , I ^- or CH ₃ COO ^- .

The quaternary ammonium compounds may be applied or incorporated in solid form or in the form of solutions or suspensions onto the fibrous web of pulp. It is also possible to use the quaternary ammonium compounds in immobilized form, for example by applying them to support materials. Suitable examples of the compounds of the formulas I, II and III and of the radicals R ¹ , R ² , R ⁴ , R ⁵ and R ⁶ as well as Ar and x are described in the WO 2006/071191 specified. Suitable compounds for the compounds of the formula IV and examples of the radicals R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² and R ¹³ and A ^- are in the EP 1 269 848 and for the compounds of the formula V and the radicals R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ mentioned therein as well as x ^- in the WO 2004/087226 shown. The cited references are hereby incorporated by reference.

In addition to the quaternary ammonium compounds according to the invention, the material web may contain further additives. These additives can be selected from superabsorbent polymers, for example based on carboxymethylcellulose derivatives or polymers based on (meth) acrylic acid and / or (meth) acrylates, and cyclodextrins, or other auxiliaries and fillers, such as titanium dioxide, chalk or kaolin , or herbal substances such as spices, fragrances, etc. be. These further additives may be present in an amount of from 0.1 to 70% by weight, preferably up to 60% by weight, based on the fibrous web.

The quaternary ammonium salts and any other additives, fillers and adjuvants should be present in the material web in such an amount that its structuring stability and tear resistance are still present for the particular application.

In one possible embodiment, the quaternary ammonium salts and any additives present are incorporated in layers in the fibrous web. A uniform effect of the substances is achieved if the substances are distributed as homogeneously as possible.

By means of the substances and additives according to the invention, web-shaped filter materials or absorption materials with a total basis weight of 20 to 600 g / m ² , preferably 30 to 500 g / m ² , can be produced.

The material web according to the invention has a fibrous web of pulp. This fibrous web can be made by any method of making such webs. The fibrous web is preferably produced by the processing method known as the airlaid method. In the airlaid process, a cotton-like product made of pulp fibers, namely fluff pulp, be deposited in an air stream and form a completely random pulp layer, which is then partially compressed in a conventional manner.

In one possible embodiment of the present invention, the quaternary ammonium salts may be applied during the airlaid process. For this purpose, the compounds in the form of solutions, suspensions or emulsions are sprayed onto the fluff pulp. It is also possible to incorporate these active ingredients in solid form in the preparation of the fluff pulp, which is usually obtained by processing pulp fibers in a hammer mill.

In a preferred embodiment of the present invention, the web of cellulose fibers is provided with embossed regions distributed over the surface of the material web, in which the cellulose fibers are pressed together more strongly than in the remaining regions and are thereby compressed with adhesive and / or binder-free. are pressed. An embossed pattern is obtained with point, area or line embossing areas. The fibrous layer is thus structured such that the pulp fibers outside of these discrete embossed areas are loosely superimposed or only weakly adhering to one another, whereas in the embossing area they form an intimate connection with the respectively adjacent pulp fibers. A complete absence of adhesives and binders to form the composite of pulp fibers allows easy and complete recycling. In the embossing areas, the fibers do not merely adhere to one another. Rather, it is achieved by the pressurization that adjacent pulp fibers are firmly and intimately connected in these embossed areas. The embossing ensures that the surface of the material web has a three-dimensional structure on at least one side. The embossing pattern may have any shape, for example, it may be a lettering or a symbol.

In a further embodiment of the present invention, the quaternary ammonium salts and optionally further additives can also be applied to the already partially compressed material web, z. B. by spraying or printing.

In applications where the strength of the fibrous webs is insufficient, further consolidation by additional melt fibers and / or binders or by water needling can be achieved.

For the adsorption and / or absorption behavior of the material web, it may be advantageous if the cellulose fibers of the layer are unbleached or low bleached or dyed.

In a further possible embodiment of the present invention, the fibrous web is composed of individual partial material webs. The density of the individual partial material webs can be different. For example, they can be connected together by a binder. With this embodiment, it is possible to further vary the properties of the material web according to the invention.

To increase the tensile strength of the material web, in a further embodiment of the present invention, this may comprise a reinforcing web, which is inserted between at least two partial fiber webs and firmly connected with these partial fiber webs to the fibrous web. As a reinforcing sheet is particularly suitable a flexible web, with a mesh web with a mesh size between 15 and 50 mm ^{2 is} particularly preferred. The reinforcing sheet may be, for example, a woven fabric, a knitted fabric or a nonwoven web. Depending on the field of application, the reinforcing web may also be a continuous film with perforations torn open in the printing areas and / or perforated. The choice of the material for a reinforcing sheet is usually based on the field of application of the material web to be produced, for example, according to the requirements of tear strength, etc.

In a further embodiment of the present invention, for. B. to increase the strength, d. H. Tear strength and / or stiffness, has the material web on one side of the fibrous web or on both sides of a cover layer of a sheet material. This sheet material may in particular be a textile, nonwoven or film-like material or even a tissue. This cover layer can be glued to the fibrous web and / or welded and / or mechanically connected. In this embodiment, the fibrous web and / or one or both cover layers may comprise quaternary ammonium compounds.

The material web according to the invention is usually produced in roll form. The material is preferably so flexible that three-dimensional bodies can be formed therefrom. In one possible embodiment of the present invention, the pleats, d. H. folded in a zigzag shape.

The material web according to the invention is particularly suitable for use in the field of hygiene, for example as an underlayer, changing table support, incontinence product, feminine hygiene product, disposable diaper or in a wound treatment system. A further field of application are food packaging, for example for fresh meat, fish, cheese, etc. In these areas, adsorbents which act in particular as odor inhibitors are used as further additives. Other suitable additives are superabsorbent polymers that can absorb body fluids.

Below, the material web according to the invention will be explained in more detail using an exemplary embodiment with reference to the drawing. Show:

1 a greatly enlarged partial section through the material web,

2 a material web in a perspective view from above and

3 a partial section through a multilayer material web

The 1 shows a partial section through the material web according to the invention. The fibrous web 1 consists of a high proportion of pulp fibers 2 , in the quaternary ammonium compound 3 is incorporated.

The pulp fibers 2 are in the stamping area 4 compacted and connected in this way. The stamping areas 4 lie on the top and bottom opposite each other, so that in the respective embossing area 4 a narrow web of interconnected pulp remains. The rest, between the stamping areas 4 arranged areas of the layer 1 have a loose pulp layer. There is no intimate connection between the pulp fibers in these areas.

The layer which determines the adsorption behavior for the substances to be removed 1 consists of pulp fibers 2 with quaternary ammonium compounds 3 and possibly further additives. The material web 1 has in the stamping areas 4 in the embodiment illustrated here, the shape of truncated pyramids or truncated cones, wherein the angle of the bevels formed thereby should preferably be between 10 ° and 45 °.

As cellulosic material for the fibrous web 1 can be used inexpensively available mass material. Preferably, a so-called "fluff pulp" is used, which is characterized by a very good binding behavior, which improves the mechanical strength of the web against vertical tensile forces.

When manufactured in a continuous process, the later becomes the layer 1 forming fibrous web from a bed of air-laid pile of pulp fibers 2 made from defiberized pulp (wood pulp) and antimicrobial (s) aggregate (s) and possibly incorporated further aggregates. For the production of a standardized, defiberized commodity, it is possible to make use of the renewable raw materials available on the market.

The method of pulp as the starting material for the layer 1 allows dry processing of the pulp fibers 2 and thus in the subsequent embossing of the multilayer web between two structural rolls a very good compaction of the pulp fibers in the discrete embossing areas. Outside the stamping areas 4 The fibers lie loosely together, what the absorption behavior for liquids to be absorbed as well as the flexibility of the layer 1 improved.

The production takes place from web material, which is manufactured in a continuous process. In air-assisted stratification, first the pulp fibers and the quaternary ammonium compounds 3 and optionally further additives to form the layer 1 placed. This is followed by the production of the embossed areas in a calender with two structured calender rolls 4 , A possible manufacturing process is z. In the European Patent 1,032,342 disclosed.

In a further embodiment of the present invention, the quaternary ammonium salts are applied in the form of solutions to the pulp, preferably shortly before this pulp is introduced into the structure of rolls. This embodiment has the advantage that the ammonium compounds distribute evenly on the pulp fibers. The supplied solvent, usually water, evaporates during the manufacturing process. Another advantage of this embodiment is that by using an aqueous solution, fine cellulose particles, which are present as dust and often have to be removed by special filters, are bound by the fine spray mist.

The pulp web 1 can be further processed in subsequent process steps to a multilayer web, as in 2 is shown. In these further continuous steps above are the topcoat 6 and below the base layer 7 arranged and with the core layer 2 connected. The web material thus produced can finally be used as a web material and cut directly on site for the particular application or immediately after the preparation or molded into a three-dimensional molded body.

Alternatively, the multi-ply web can also be made by applying the topcoat 6 or the base layer 7 initially used as a carrier layer. On this carrier layer 6 respectively. 7 becomes the bed of pulp fibers 2 and optionally attached quaternary ammonium salts and other auxiliaries and additives 3 applied in the air stream. Subsequently, this arrangement of carrier layer and bed is passed together through the structural rollers of the calender. Alternatively, previously, ie before the final passage through the calender, the other of the two layers 6 . 7 , which is not already the carrier layer, nor on the pulp layer 1 be hung up.

The other layers can be subsequently applied in a conventional manner. If the other layers are subsequently applied, then they can have any surface structure, for example smooth.

In an alternative embodiment of the present invention, the quaternary ammonium salts are not applied directly to the pulp fibers or incorporated into the layer of pulp fibers, they can also be applied to the cover layer 6 or the base layer 7 be applied, for example, in their pure form or in the form of aqueous solutions.

The 3 shows in a view obliquely from above in the embodiment of a total of three layers or layers 6 . 1 and 7 composite material web.

The lowest layer is a base material 7 and as the topmost layer, a topcoat 6 , If the material web used as a hospital pad, the top layer should 6 be permeable to the body fluid to be absorbed. The base material 7 is preferably impermeable to this application to prevent passage of body fluid (s) onto the mattress. The base material may, for. B. be formed by a film.

Above the base material 7 is, in this embodiment, the entire surface in contact with this, a layer 1 from pulp fibers, which optionally contains quaternary ammonium compounds and other additives. This layer 1 is permeable to body fluids, they are made of the pulp fibers of the layer 1 added. When used as an absorbent absorbent material, the layer shows 1 a high absorption capacity for liquids, especially for body fluids. It is in the embodiment shown here on its upper side over its entire surface with a cover layer 6 in contact and covered by this. The cover layer 6 additionally serves to protect the pulp web from damage and destruction during use.

To the base material 7 and the topcoat 6 To distinguish easier from each other, it has proven to be advantageous to mark one or both sides. In this way, if this is used as a medical document, z. B. Nursing staff quickly recognize even at high workload, which side is above and which below. A particular advantage of marking the pages in color is in such an application that the mark through the bed sheet appears through and is visible. When changing the bedding, the nursing staff sees that under the sheet is a mattress, which must be removed before the bed sheet is placed in the laundry.

The material web according to the invention may be surrounded by further layers which are larger than the pulp layer 1 and the layers possibly arranged thereon 6 and 7 , are connected to each other without the web is detected. These further layers form an envelope for the material web. They may be of textile, non-woven or foil-like material or of tissue.

LIST OF REFERENCE NUMBERS

1

Fibrous web

2

Cellulose fibers

3

Aggregate, quaternary ammonium compound

4

stamping area

5

multilayer material web

6

topcoat

7

base material

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2006/071191 [0009]
• EP 1269848 [0009]
• WO 2004/087226 [0009]
• EP 1032342 [0035]

Claims (12)

Material web with a bonded fibrous web ( 1 ) of pulp consisting of a layer of pulp fibers ( 2 ) which are pressed together in some areas, characterized in that one or more quaternary ammonium compounds ( 3 ) in the fibrous web ( 1 ) are contained as aggregates. Material web according to claim 1, characterized in that the quaternary ammonium compounds are selected from compounds having the following formulas:

wherein R ¹ and R ^{2 are} independently selected from linear or branched (C ₁ -C ₆ ) -hydrocarbon chains, x is from 0 to 1, R ^{4 is} selected from a direct bond or a linear or branched (C ₁ -C ₆ ) Hydrocarbon chain, R ^{5 is} selected from hydrogen or a linear or branched (C ₁ -C ₆ ) hydrocarbon chain, R ^{6 is} selected from a direct bond and a linear or branched (C ₁ -C ₆ ) hydrocarbon chain, and Ar ^{7 is} an N-containing heteroaromatic group, and wherein the polymer precursor is modified such that at least a portion of the N atoms are substituted with a substituent selected from the group consisting of linear or branched (C ₁ -C ₂₀ ) alkylene, and at least a portion of the N atoms in this polymer precursor are quaternary,

wherein R ^{2 is} an alkylene group having 3 to 10 carbons, R ^{4 is} a heteroalkylene group having 2 to 6 carbon atoms and A ^{- is} an anion and R ¹⁰ , R ¹¹ , R ¹² and R ^{13 are} each independently an alkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms or an alkenyl group having 2 to 4 carbon atoms; and / or compounds of the formula V

wherein R ^{14 is} a C ₁ -C ₃₀ alkyl group, preferably a C ₈ -C ₃₀ alkyl group, R ¹⁵ , R ¹⁷ and R ^{18 are} each independently a C ₁ -C ₃₀ alkyl group or hydrogen and R ^{16 is} a C ₁ -C ₃₀ alkylene group, and X is a counterion such as Cl ^- , Br ^- , I ^- or CH ₃ COO ^- . Material web according to claim 1 or 2, characterized in that the quaternary ammonium compounds are brought in solid form or in the form of solutions or suspensions. Material web according to one of claims 1 to 3, characterized in that the quaternary ammonium compounds are applied to carrier materials. Material web according to one of claims 1 to 4, characterized in that the quaternary ammonium compounds ( 3 ) and / or other aggregates homogeneously in the fibrous web ( 1 ) are incorporated. Material web according to one of claims 1 to 5, characterized in that it has a total basis weight of 20 to 600 g / m ² , in particular from 30 to 500 g / m ² . Material web according to one of claims 1 to 6, characterized in that the fibrous web ( 1 ) was prepared by an airlaid method. Material web according to claim 7, characterized in that the pulp fibers of the fibrous web ( 1 ) in an embossed pattern of punctiform or linear embossed areas ( 4 ) are pressed together and compressed adhesive and / or binder-free in the embossing areas of the embossing pattern due to high pressure. Material web according to claim 8, characterized in that the surface has a three-dimensional structure on at least one side. Material web according to one of claims 1 to 9, characterized in that on one side or on both sides of the fibrous web ( 1 ) a train ( 6 . 7 ) is arranged from textile, fleece-like or foil-like material. Material web according to claim 10, characterized in that the quaternary ammonium compounds on one or both tracks ( 6 . 7 ) are applied. Material web according to claim 11, characterized in that the quaternary ammonium compounds in the form of a solution or suspension on the web ( 6 . 7 ) is applied.

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