DK153894B - ABSORBING MASS COMPREHENSIVE CELLULOSE FLUID OF IMPROVED COLOR AND DISPOSABLE PRODUCTS CONTAINING THIS ABSORBING MASS - Google Patents

Description

... DK 153894B

The present invention relates to an absorbent mass comprising cellulosic moisture derived from thermomechanical pulp and a disposable product comprising the absorbent mass. The flakes are used as the primary absorbent mass in these products, and reference may be made to such recent patents as US Patent Nos. 4,069,821, 4,066,081, 4,062,362, 4,060,085, 4,044,768, 4,029,101, 4,029 .100 and 4,027,672, wherein cellulosic fluff is used as an absorbent pulp in products of the type of the present application. The said patents are incorporated herein by this reference. The pulp used to make the flakes in these prior patents has generally been chemical pulp, and such wood flakes are a very bleached product with a whiteness of approx.

90 or more. The standard whiteness of 10Q is based on a 15 magnesium carbonate surface and is accepted as criteria for excellent whiteness. Chemical pulp is also advantageous in providing optimum fiber lengths of the wood, leading to absorbent pads of acceptable structural completeness (i.e., strength and shape stability) which are highly desirable, since the method of forming the pad is generally by laying down. with air.

It has been found desirable and advantageous to use thermomechanical pulp in disposable absorbent structures, not only because of the obvious economic advantage, but also because of improvements in absorbency. The latter is the result of the semi-hydrophobic nature of thermomechanical pulp due to the presence of natural lignins, which gives the nonwoven pad greater elasticity and articulated increased fluid retention ability.

One of the disadvantages of thermomechanical pulp lies in the unclean color of the product which makes disposable articles made less desirable to the consumer, especially those consumers who use disposable diapers on toddlers, where a very

2 DK 153894 B

white product is a requirement.

It has now been found that the whiteness of thermomechanical pipe can be greatly improved and approach the whiteness of the best chemical pulp (i.e., liberated from lignin and bleached) by treating the pulp, preferably in slurry form, with a mixed dye system comprising ( a) Color-Index acid violet 49 and (b) Color-Index acid violet 47 in a weight ratio of 4: 1 to 1: 1, so that the pulp gets from 0.001% to 0.05% by weight of dye calculated on the dry pulp weight.

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Color-Index acid violet 49 is a triphenylmethane type dye (Color-Index Ko. 42640) and Color-Index acid violet 47 is an anthraquinone dye (Color-Index No. 47).

* 5 The dye mixture is conveniently added to the aqueous pulp (usually about 85-90% solids or more) as a solution, preferably aqueous solution, but any suitable dye solvent (e.g., alcohol, alcohol and water) can be used. The dye solution may be of any desirable concentration, but it is generally preferred to use dilute solutions to avoid over-staining in local parts of the pulp, which may occur as a result of rapid and fairly high extraction of the dye from the solution on the pulp's cellulose material.

After treatment, the pulp is handled in the usual manner to form plate products for any subsequent use, and in particular, the pulp can be converted into plate to form cardboard used to make absorbent fluff for the above disposable products.

The following examples illustrate the invention.

Example 1 35

To 1.5 g of an aqueous cellulose pulp (thermomechanical pulp,

; First DK 153894B

3 is not liberated from lignin) with 90% solids cellulose 3 is added 50 cm of a dye solution containing (a) 5 7.5 mg / l of Color Index acid violet 47 and (b) 2.5 mg / l of

Color Index acid violet 49. After drying the pulp, after sieving to form a plate, it turns out that the Tappi clarity measured in the usual manner on a G.E. reflectometer is 80%, whereas untreated (i.e., without dye treatment) 10 pulp converted to plate similarly has a Tappi clarity of only 65%. The dye-treated product not only has improved clarity and clarity but is equivalent to the usual chemical pulp (liberated from lignin) when converted to plate in a similar manner, despite the presence of the lignin in the thermomechanical material.

It may also be desirable to add a small amount of titanium dioxide or barium sulfate pigment to the aqueous pulp to further make the product white. Generally, only very small amounts of about 0.01% to approx. 10 wt% and preferably 0.5 to 3 wt% excellent results, as shown in the following example.

Example 2 a) Example 1 is repeated with the addition of the dye solution of 0.5 g / l titanium dioxide.

b) Example 1 is repeated with the addition of the dye solution of Q, 5 g / l barium sulfate.

In the case of cases al and bl, the clarity value of the sample is 85%.

The invention has been described with reference to a blend of dyes Color-Index 47 and Color-Index 49. One of the significant features of the Color index 47 dye (0.001% in water) is a prominent absorption in the visible range from ca. 4800 Angstroms to approx. 6000 Angstroms with a flat

Claims (2)

An absorbent mass suitable for absorbing body fluids comprising cellulosic fluids derived from thermomechanical pulp such that the flakes are air-filled, characterized in that the flakes are treated with a mixed dye material comprising Color-Index dye 47 and Color-Index dye 49 in a weight ratio of 4: 1 to 1: 1, wherein the flies contain from 0.001 to 0.05% by weight of dye mats in all et al. 2. A disposable product suitable for absorbing body fluids and comprising an absorbent mass for the body fluids, a water-impervious backing and a cover layer, characterized in that the absorbent mass is as defined in claim 1. 25 30 35