DE1619013A1 - Method for consolidating material made up of fibers, in particular sheet-like material - Google Patents

Description

PATENTANWÄLTE, ₀ /, _{c /} o _Q ίο

78/25/29 g MÖNCHEN 22 · "·

DR.-ING. WOLFF, H. BARTELS, ⁸ Schstwssea DR. BRANDES, DR.-ING, HELD phone = «with) 293297

Registration number. 120 781

EASTMAN KODAK COMPANY, 343 State Street, Rochester, New York State, United States of America

Method for consolidating fiber-based, especially sheet material

Materials made of fibers, such as paper, felt and fabrics, are known to be used in a wide variety of areas, for example in the packaging and clothing sector and as carrier materials for photographic emulsions. In all these cases, the materials made up of individual fibers must be in a dry as well as in a wet state have a certain minimum strength.

The invention was based on the object of providing a method for solidifying which can be carried out quickly and easily and which is inexpensive of materials made up of fibers, in particular sheet-like materials, in which there is no inappropriate

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Modification of the desirable properties of these materials, their strength in both dry and dry conditions can improve when wet.

The invention was based on the knowledge that the asked The problem can be solved by treating the materials made up of fibers with certain amine oxides.

The invention accordingly provides a method for consolidating material made up of fibers, which is characterized in that the fibrous material is mixed with an amine oxide of the following formula:

I '

R, N »O

R,

wherein R-, R ₂ and R _{3 are} each either optionally substituted alkyl, cycloalkyl, aralkyl or heterocyclic radicals or two of the radicals R «, R- and R _{3 can} together form a heterocyclic ring,

treated and heated to a temperature at which the Amine oxide causes the fibers to swell.

When carrying out the method according to the invention comes there is no discoloration or degradation of the fibers

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constructed or existing material. Residues leading to disadvantages do not remain in the treated material »The Materials treated according to the invention have a permanent or at least long lasting strength * These properties are achieved by washing these materials with water not repealed *

Particularly suitable for carrying out the process of the invention amine oxides are cyclic N-methylamine oxides of the general formula:

CH,.

Z N — fO, * ^ '

where Z is the atoms necessary to complete a saturated heterocyclic ring.

Particularly advantageous ones falling under the formula given Connections are for example:

N-methylraorpholine-N-oxide, N-methylpipefldine-N-oxide, N-methylpyrrolide-N-oxide, N-methylazacyclcheptane-N-oxide and Nicotine t-oxide.

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A typical example of one suitable for carrying out the method according to the invention and under the general amine oxide formula falling amine oxide is triethylamine-N-oxide »

The fibrous material can either be soaked directly with the amine oxide present in liquid form or with a solution of the Amine oxide dissolved in a liquid solvent can be treated. If solvents are used, one can either volatile solvents that can be easily removed by evaporation or also liquid solvents that cannot be removed by evaporation Use solvents. In the latter case, the particular solvent used may have the strengthening effect of the respective Do not adversely affect amine oxide on the material consisting of fibers

During or after the fibrous material with the amine oxide is or has been treated, in particular soaked, it is necessary to use a sufficiently high temperature, so that the amine oxide can act on the fibers as a solvent or swelling agent. This temperature can vary greatly and depends on the amine oxide used or the fiber material to be treated * In the Cases where the amine oxide is applied either neat or in the form of a solution in a volatile solvent the required minimum temperature the melting point temperature

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of the amine oxide in question will not become a through evaporation solvent to be removed is used, the minimum temperature required is quite simply the temperature at which the solution of the amine oxide causes the fibers to swell or begins to dissolve. This temperature depends on the individual components the solution and its concentrations.

Suitable volatile solvents are e.g. water, methanol and acetonitrile. Suitable solvents that cannot be removed by evaporation are, for example, dimethyl sulfoxide and N-methylpyrrolidone and sulfolane.

After the amine oxide has acted on the fibrous material and has caused its solidification, the amine oxide can, for example, by washing with water or another, for the relevant amine oxide selective solvent are removed.

The most varied of these are referred to as "fibrous material" To understand products and articles (e.g. woven and non-woven fabrics) that are made from or are soluble in amine oxides swellable fibers are built up or at least predominantly consist of them. The fibers can for example consist of natural cellulose fibers, such as in the case of wood pulp, tree corrugation, linen and the like. Or made of animal fibers, as in the case of wool, fur and the like,

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or from synthetic fibers such as polyamide, rayon and Polyester fibers and mixtures thereof. The fibers can either form aggregates or clusters, such as for example in the case of papers or in felted and so-called, non-woven "non-woven" products and the like. Or they can be in In the form of woven and knitted fabrics.

The method according to the invention is particularly suitable for consolidating papers made from cellulose fibers.

One possible mechanism by which the amine oxides take effect is is to be explained using the example of the treatment of a paper made of cellulose fibers.

If such a paper is treated with an amine oxide, it dissolves this on the surface areas of the cellulose threads forming the paper structure or causes them to swell, which allows them to merge or weld into a solid fiber network. Before the treatment with the amine oxide, the paper consists of Fibers, which are mainly held together by the forces occurring between the individual fibers.

The described mechanism of the solidification process results from photomicrographs of a cellulose Single layer of paper before, during and after the treatment with an amine oxide «Obviously during the treatment

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also the fine grus in the structure of the paper Cellulose fibers fused, becoming an essential Becomes part of the paper itself. This process can also weaken the dust-forming properties of paper.

By the same mechanism, flaking of the flakes of flaky fibers such as wool is evident. reduced. In solidifying woven articles, the amine oxides act by the same mechanism, and presumably they do weld the warp threads to the weft threads. Simultaneously the twisted single threads are stiffened by welding the fibers in the thread. This gives the fiber and Twisted threads create a stronger physical connection than is possible through the forces between the individual fibers.

Most of the known methods of improving the strength or stiffness of papers in the dry and wet states exist to provide the paper surface with a coating of a certain material or the paper structure with to soak a certain material. The stiffening takes place here either by chemical reaction of the relevant Material with the paper or in that this material remains a part of the treated paper. With such treatment however, on the one hand, the paper can be degraded or, on the other hand, it can be harmful or undesirable in this Chemicals remain behind.

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Another known method of stiffening paper is to coat it with a material which a continuous, stiffening phase forms either in the paper structure itself or on the paper surface. This method of stiffening paper is typically expensive and produces a rigid or brittle paper.

The amine oxides used according to the invention go neither with the Paper still undergoes a chemical reaction with the fibrous materials treated with it, nor is it required to be part of them of the stiffened material.

The method according to the invention overcomes many of the disadvantages of the known methods of stiffening paper. Since the amine oxides used do not react with the paper fibers and the Temperatures to which the paper must be heated are not extreme, no chemical degradation takes place in the fibers. The end product stiffened after the treatment need no longer contain amine oxide. In this way it can be avoided when carrying out the method according to the invention, discoloration or any strong smelling or otherwise harmful chemicals must remain in the finished product.

Another advantage of the method according to the invention is that the amine oxide is recovered and reused

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because on the one hand it does not react with the fiber and on the other hand does not have to remain in the finished product. Thus, the method according to the invention is relatively cheap, simple and effective.

Since the fibrous materials imparted both in the dry and in the wet state, no improved strength depends on whether a stiffening agent is present in the finished product the material can be treated without taking any precautions to protect the stiffener Need to become. The stiffened products obtained by the process of the invention can be treated with water, an aqueous acid, an aqueous base or organic solvents, such as methanol or acetone, can be washed and dried again without losing their improved strength. Is a stiffened which can be produced according to the invention. Paper used as a carrier for layers to be applied on it, so the coatings can be applied using solvents without sacrificing strength the wearer suffers * Correspondingly, the improved Strength of fabrics or products consolidated by the process of the invention which are dyed should not be adversely affected by the dye solvent.

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The following examples are intended to further illustrate the process of the invention.

example 1

In a shallow dish, which was held by a thermostat at 110 ⁰ C, 20 g of N-methylmorpholine-N-oxide melted · A strip of Whatman paper (j ^ M) was rapidly pulled through the melt and then immediately with methanol or if necessary also washed with water and dried

the JRöC resistance values, expressed in kg / cm -mindens /

untreated treated wet 0 4.13 dry 0.84 7.21 Example 2

A solution of 10 g of N-methylmorpholine-N-oxide in 20 ml of Dime Thylsulfoxyd was in a shallow dish which was using a thermostat was kept at 100 ° C, heated. A strip of Whatman paper (# 4) was taken at such speed pulled through this solution so that both sides of the sheet were completely wetted. The paper was

The burst strength was determined using a test device from

Minden Paper Gauge Company, New York, USA,

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then heated to 120 ° G, with methanol or optionally also washed with water and then dried. The paper strengthened in this way was wet and dry Condition following folding strength values, expressed in kg / cm -Mindtni

treated untreated

wet O 2.73

dry 0.84 4.34

Example 3

A piece of Whatman filter paper (# 1) was treated with a methanolic solution of 25-1igen N-methylmorpholine-N-oxide impregnated · Then the paper was heated for 1 minute to 120 ⁰ C, then washed with water and dried "in The paper stiffened this way had in wet and dry

2 Condition following folding strength values, expressed in kg / cm - Minden;

treated untreated

wet 0 2.94

dry 1.33 5.32

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The strength or stiffness of the treated paper was determined by

Washing with water, an aqueous acid, or an aqueous one Base hardly affected. Samples of the with N-methylmorpholine-N-oxide treated paper was kept in running water for 18 months. The loss of strength or stiffness was both in the wet and in the dry state less than 5 1.

Example 4

In the following Table I the effectiveness of a number of amine oxides specified as stiffening agents for paper. Of each of the amine oxides listed in Table I, one was 50% methanolic solution prepared, each of which was filled into a shallow bowl. In each of these solutions was dipped a sheet of Whatman filter paper (# 1), then removed and drained to remove excess solution left and heated to 120 ° C. The papers solidified in this way were wet and dry the following folding strength values, expressed in kg / cm -Minden:

- 13 -

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Table I.

Amine oxide

Comparison test (untreated paper)

N-methylpyrrolidine-N-oxide, N-methylpiperidine-N-oxide N-methylazacycloheptane-N-oxide, N-methylmorpholine-N-oxide Nicotine-1-oxide

Folding strength
• when wet
in kg / cm2

2.45
4.27
3.15
4.55
4.06

Fold strength in the dry state in kg / cnr

1.33

4.27 7.63 5.95 8.26 6.44

Example 5

The following Table II shows the relationship which exists between the concentration of amine oxide in the to stiffen the respective The methanolic solution used for the paper and the folding strength values to be achieved therewith exist. This was done the procedure described in Example 4 was repeated, with the exception that different concentrations of N-methylmor- » pholine-N-oxide in the methane formulation intended for treatment Solution were used. The papers consolidated in this way had those in the wet and dry state Fold strength values given in Table II below.

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Konζ, an N-methylmorpholine-N-oxide

Vergleidhsversuch (untreated paper)

50%

25 I 12.5 I.

Table II Folding strength
in the dry too
was standing Folding strength
in the wet too
was standing in kg / cm in kg / cm 1.33 0 8.26 4.55 5.32 2.94 4.06 2.17

Example 6

A piece of paper, consisting of 85 I of bleached sulfite pulp and 15 1 of polyethylene terephthalate fibers, was with a 20-1 solution of N-methylmorpholine-N-oxide soaked in ethanol. The paper was then heated to $ 12 for one minute, then washed with water and dried. What paper solidified in this way possessed in both wet and dry conditions Condition following folding strength values, expressed in? kg / cm -Mindeni

wet dry

untreated

0
0.84

treated

2.94 5.46

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Example 7

A piece of paper consisting of 75 liters of bleached sulfite pulp and 25% rayon fibers (30 denier, 3.81 cm long) was used with. a 20% methanolic solution of N-methylazacycloheptane-N-oxide. Then the paper was heated for 1 minute to 120 ⁰ C, then washed with water and dried _# The solidified in this manner had paper in the wet and dry state, the following Falzfestigkeitswerte, expressed in kg / cm -Minden.

treated untreated

wet 0.07 2.59

dry 0.63 6.86

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Claims (8)

- IO - r claims 1) A method for consolidating made up of fibers, in particular sheet-like materials, characterized in that 4 <Φ the fibrous material with an amine oxide of the following formula: R ₂ -N wherein R-, R ₂ and R ₃ are either optionally substituted alkyl, cycloalkyl, aralkyl or heterocyclic radicals or two of the radicals R, R ₂ and R ₃ can together form a heterocyclic ring, treated and heated to a temperature at which the amine oxide causes the fibers to swell 2) Process according to claim 1, characterized in that the amine oxide used is N-methylmorpholine-N-oxide, N-methylpiperidine-N-oxide, N-methylpyrrolidine-N-oxide, N-methylazacycloheptane-N-oxide or nicotine-1- oxide used. 0 098 3 9/1982 3) Method according to claims 1 and 2, characterized in that treating the fibrous material with a solution of an amine oxide in a non-volatile liquid solvent. 4) Process according to claims 1 to 3, characterized in that that the fibrous material with a solution of an amine oxide in dimethyl sulfoxide, N-methylpyrrolidone, sulfolane or mixtures thereof. 5) Process according to claims 1 and 2, characterized in that that the fibrous material is soaked with a solution of an amine oxide in a volatile, liquid solvent and removing the solvent from the fibrous material before heating it to a temperature at which the amine oxide causes the fibers of the fibrous material to swell. 6) Method according to claims 1, 2 and 5, characterized in that that the fibrous material with a solution of an amine oxide in methanolj water, acetonitrile, methanol-bioxane, Methanol-acetone or mixtures thereof soak. 7) Process according to Claims 1 to 6, characterized in that the amine oxide is used following the heat treatment removed. 009839 / 19J2 8) Method according to claims 1 to 7 "characterized in that that a sheet-like material consisting of cellulose fibers is used as the fibrous material.