NO811651L - TREMASSES CONTAINING A HYDROPHIL BINDING REMOVER AND PROCEDURE USING SUCH AGENT - Google Patents

Abstract

Cellulose-containing pulp with reduced breaking strength. and excellent hydrophilic properties. The mass produced-; using a hydrophilic bond remover of the general formula :. where:. = methyl, ethyl, propyl, hydrogen or hydroxyethyl ,. R = methyl, ethyl, propyl or [ethylene oxide] wherein. n = 1-50, = aliphatic chain with at least 4 carbon atoms ,. R [ethylene oxide] or [propylene oxide] wherein. n = 1-50, and. X = Cl, I, Br, SC ~, PO ~, CHCO.

Description

The present invention relates to a mass which has

low breaking strength and excellent hydrophilic properties produced by the incorporation of a hydrophilic debonder of the quaternary amine type.

In recent years, constant attempts have been made

on improving the specific properties of cellulosic pulp-derivative products using a variety of different debonding agents. These debonding agents quite often contain a quaternary amine component due to the high degree of independence of this part for cellulose. Examples of quaternary amine debonders are found in US Patent Nos. 3,554,863, 3,554,862. 3,395,708 and Reissue 26,939. Additional examples of such debonders are found in US Patent No. 3,617,439, Canadian Patent No. 1,020,935, British Patent Nos. 1,282,593 and 1,180,801, as well as in US Patent No. 3,556,931, 3,510,246 and 3,356,526.

Until fairly recently, it has been axiomatic in the pulp and paper industry that debonding function was inversely related to hydrophilicity, i.e. the increase in debonding efficiency represented by reduced breaking strength would result in reduced water absorption. US Patent No. 4,144,122 describes a quaternary amine compound containing repeating ethylene oxide units at two of the quaternary positions. These ethylene oxide units are attached to the ammonium ion with propylene bonds in each case and are also characterized by an ether bond to an aliphatic chain in both positions.

According to US Patent No. 4,144,122, bond removal is achieved, while the hydrophilic character of the pulp treated for bond removal is improved compared to conventional pulps treated in such a manner.

According to the present invention, it is identified

another class of such bond-removal compounds which provide pulp that is even more hydrophilic than the pulp prepared according to US patent 4,144,122.

According to the present invention, a hydrophilic bond remover is provided with the general formula:

where:

= methyl, ethyl, propyl, hydrogen or hydroxyethyl,

R2= methyl, ethyl, propyl or [ethylene oxide] where

n = 1 to 50, R^ = an aliphatic chain of at least 4 carbon atoms,

R^= [ethylene oxide] n or [propylene oxide] where

n = 1 to 50 , and

X = Cl, I, Br, SO~, PO~, CH 3 CO 2 .

Compounds of this general formula actually show increased capacity with respect to the production of hydrophilic mass compared to the compounds described in US Patent No. 4,144,122. Any of the selected chemicals defined by the above general formula may be introduced into the pulp or pulp sheet at a number of different locations during the forming operations of the commercial pulp sheet. Due to the hydrophilic properties of the pulp after treatment with the bond remover, the application of products produced from this pulp varies from fluff used in conventional absorbent materials such as sanitary napkins and diapers to absorbent sheet materials such as paper towels. With regard to diapers, it should be pointed out that a number of absorption tests indicate a significant increase in the absorption of urine compared to more conventional bond removers and therefore the products according to the present invention have a special beneficial effect in diaper products. (The terms diapers and diaper products used shall here in particular include all incontinence pads and products, whether they are specially designed for children or adults or whether they are in sheet form such as for use by children or adults with incontinence problems in a hospital or orphanage.)

Quaternary amraonium compounds according to the invention

should be added to the wet pulp after delignification or bleaching, either before or during formation into sheets or continuous webs in the pulp machine or a paper machine. The compounds are preferably in an aqueous carrier in a concentration in the range from approx. 1 to approx. 15% by weight of the bond remover. These treatment solutions may also contain conventional viscosity-reducing additives

such as ethanol, propanol, monoethyl ether or diethylene glycol, and other additives which are traditionally associated with processes for the addition of bond removers. The amount of the new bond remover based on the dry weight of the cellulose varies from approx. 0.1 to approx. 5.0% and preferably between approx. 0.2 and

es.. 2 f 5 "o •

The treatment solution can be applied by mixing with a pulp slurry. It can also be applied by spraying or dipping, using so-called kissing rollers or using other suitable techniques. After application, the treated cellulose pulp or paper can be dried in the usual way. The treated cellulose can be converted into cellulose fluff as mentioned above, for use in various hygienic products. In all other respects, paper and pulp processing associated with handling pulp containing these compounds is essentially conventional.

Fruit products covered by the present invention

are commercially available and. sold under the trade name: "ETHOQUAD", and is generally used for antistatic agents, bath additives for electroplating and pigment leveling agents. Also useful is the class of compounds marketed under the designation "EMCOL" and used for similar purposes.

An example of bond removers according to the invention is given below. The example compares the debonding ability measured by blasting according to Tappi standard method T40 3 OS-76 and breaking strength according to Tappi standard method T494 OS-70. Water absorption is determined using the following method. Specimens are obtained from bond remover-treated hand sheets by cutting three random strips of size 25 mm X 75 mm from each sheet. It is found that five sheets are sufficient for each test condition. Each strip is marked at 0.5 cm intervals for a length of 3.5 cm starting from the edge of the 25 mm end.

Deionized water (surface tension = 72 dyne/cm) is placed in a two-litre glass bottle. Test strips are attached to the bottle just above and perpendicular to the liquid surface. The liquid level is then adjusted until the liquid surface just contacts the strip. The sheet then absorbs the liquid that rises in the strip. A light source placed behind the bottle helps the observation of the rise of the liquid. When the liquid contacts the first 0.5 cm line, a timer device is started. Each time the liquid touches the next higher 0.5 cm line, the time is recorded. This results in 90 measurements for each test condition (3 strips/sheet x 6 measurements/strip X 5 sheets/test condition).

The speed is determined by fitting the data to a regression in the height traveled up the strip against the square root of the time required for this. The square root is written from the application of the Lucas-Washburn equation. The fits are excellent with r > 0.98 in all cases considered. This results in speeds calculated to be better than<+>4%. All data obtained are corrected for density.

For all described experiments, hand-made

sheets with a basis weight of 9.8 g/1000 cm 2. Three compounds according to the invention were prepared as bond removers and with the following formulas:

These compounds were tested against the commercially available bond removers "QUAKER 2006" and "ARQUAD 2HT-75", as well as "BEROCELL 579, 582 and 584" manufactured according to US Patent No. 4,144,122. The structure of the "BEROCELL" compounds is not specifically identified other than by patent specification; The "ARQUAD" compound is a quaternary amine with a methyl group at R₂ and R₂ and saturated C₁₂ groups at R₃ and R₄. The "QUAKER 2006" compound is not specifically stated by the manufacturer, but it is believed to have a five-membered ring structure containing two nitrogen atoms with one nitrogen atom doubly bonded to one of the carbon atoms in the ring structure, the other nitrogen atom having two substituents attached to it

in addition to the bond associated with the ring structure.

By comparison according to the one described above

test, the following values were determined:

While sufficient breaking strength reduction is achieved with the bond removers according to the invention, it appears from the above data that significantly improved water absorption is provided with the same compounds in comparison with e.g. "BEROCELL" compounds which allegedly provide increased hydrophilicity for the bond removers described in US Patent No. 4,144,122. These values are correct for different levels of bond removers. What is even more important in certain cases at lower addition levels for bond removers according to the invention is that the hydrophilicity of the pulp treated with bond removers is actually greater than that of the untreated pulp.

The above table also illustrates that the data, although they change somewhat as the mass source changes, are valid in the same general size range.

When the compounds according to the invention were tested for urinary absorption, based on a synthetic urine containing the following compounds: the values obtained were significantly greater than those for comparable commercially available bond removers, as can be seen from the table below:

As can be seen from the above table, significant beneficial effects are achieved from the use of the present bond remover when the end product is intended for

to be a fluff material that is later used in diapers or products of a similar type.

As mentioned above, the increase in hydrophilicity can naturally have significant additional beneficial effects with respect to fluff in its conventional applications such as e.g.

in sanitary napkins or other hygienic products.

Claims (13)

1. Wood pulp, characterized in that it contains a hydrophilic bond remover with the general formula: where: = methyl, ethyl, propyl, hydrogen or hydroxyethyl, R0 ^ = methyl, ethyl, propyl or [ethylene oxide] where n = 1-50, R^ = aliphatic chain with at least 4 carbon atoms, R4 = [ethylene oxide]n or [propylene oxide] where n = 1-50, and X = Cl, I, Br, SO~, PO~, CH3 CO2 . 2. Method for treating cellulose pulp fibers to reduce bonding between fibers while preserving the hydrophilicity of the pulp, characterized in that to a slurry of cellulose pulp fibers before or during the formation of the slurry into a web, a quaternary ammonium compound with the formula is added: where: R^ = methyl, ethyl, propyl, hydrogen or hydroxyethyl, R~ = methyl, ethyl, propyl or [ethylene oxide] where n = 1-50, R, = aliphatic chain with at least 4 carbon atoms, R^ ■= [ethylene oxide] n or [propylene oxide]n where n = 1-50, X = Cl, I, Br, SO~, PO~ , CH 3 CO 2 and forming and drying said web. 3. Method according to claim 2, characterized in that the quaternary ammonium compound is in an aqueous carrier in amounts from 1 to 15% by weight. 4. Method according to claim 2, characterized in that the quaternary ammonium compound is applied to the fibers in an amount of from approx. 0.1 to 5.0% based on the dry weight of the cellulose. 5. Method according to claim 2, characterized in that the quaternary ammonium compound is added by spraying a solution thereof onto the web, and the web is dried. 6. Method according to claim 2, characterized in that the quaternary ammonium compound is added to the slurry of cellulose pulp fibers, and the pulp is then dried. 7. Method according to claim 2, characterized in that the web is divided into fibers for cellulose fluff. 8. Method according to claim 2, characterized in that the quaternary ammonium compound is added during the formation of the slurry of cellulose pulp fibers into a web. 9. Combination according to claim 1, characterized in that the bond remover is present in an amount from approx. 0.1 to 5.0% by weight of the dry cellulosic material. 10. Absorbent fluff material, characterized in that it contains the hydrophilic bond remover according to claim 1. 11. Absorbent fluff material according to claim 10, characterized in that the hydrophilic bond remover is present in an amount from approx. 0.1 to 5.0% by weight of the dry cellulosic material. 12. Diaper, characterized in that it contains an absorbent fluff material having a hydrophilic bond remover of the general formula: where R1 = methyl, ethyl, propyl, hydrogen or hydroxyethyl, R2 = methyl, ethyl, propyl or [ethylene oxide]n where n = 1-50,' R3 = aliphatic chain with at least 4 carbon atoms, R^ = [ethylene oxide] or [propylene oxide]n where n = 1-50, and X = Cl, I, Br, SO~, PO~, CH3 CO2 . 13. Absorbent cellulose-based sheet material, characterized in that it contains a hydrophilic bond remover with the general formula: where: R^ = methyl, ethyl, propyl, hydrogen or hydroxyethyl, R2 = methyl, ethyl, propyl or [ethylene oxide]n where n = 1-50, R3 = aliphatic chain with at least 4 carbon atoms, R^ = [ethylene oxide] or [propylene oxide]n where n = 1-50, and X = Cl, I, Br, CO~, PO~, CH3 CO2 .