DE1222363B - Process for the production of papers consisting at least partially of man-made fibers - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

D21h

German class: 55f-16

Number: 1222363

File number: S75536VIb / 55f

Filing date: August 31, 1961

Opening day: August 4, 1966

The invention relates to a process for the production of at least partially from man-made fibers existing papers, in which produced from an aqueous suspension of the fiber material Paper impregnated with a polyamide binder solution and dried hot, if necessary under pressure will.

"Papers" do not include paper-type products made on a paper machine to understand woven fabrics and the like flat structures.

For the production of papers and exclusively made of synthetic fiber material Various methods have been developed for paper-like structures. Production runs counter to this Corresponding products made from mixtures of synthetic, man-made and cellulose fibers for lack Ability of the former to fibrillate and because of their physical and chemical differences Behavior of the fiber components on difficulties.

A method has been proposed which succeeded in using modified Polyamide resins as binders Cellulose-containing papers and paper-like structures with excellent mechanical properties Produce properties in which, for example, the strength and the porosity through Change of process conditions - in particular by adjusting the content of polyamide fibers - can be varied or improved at the same time independently of one another. With this one Process, it is necessary that the N-alkoxy polyamide used as a binder to achieve a good solubility is relatively highly substituted, which is in the subsequent process stages possibly to difficulties due to formaldehyde elimination and to a certain tendency the papers can lead to sticking during hot pressing.

The use of amine-formaldehyde precondensates is known in paper sizing. Here it is a treatment which, in addition to a certain wet strength, particularly gives the paper gives water-repellent properties, whereby products are obtained that are no longer readily available can be impregnated.

In a known method, the sizing of fibrous structures such. B. Natural paper Cellulose material with emulsions of curable synthetic resins from z. B. formaldehyde and phenols or urea-thiourea.

It is also known to use finished paper sheets with adhesive processes for the production of at least
Papers consisting partly of man-made fibers

Applicant:

Societe de la Viscose Suisse,
Emmenbrücke (Switzerland)
Representative:

Dr. E. Wiegand and Dipl.-Ing. W. Niemann,
Patent Attorneys, Munich 15, Nussbaumstr. 10

Named as inventor:

Dr. Bruno S. W. Marek,

Josef Gneisz, Emmenbrücke (Switzerland)

Claimed priority:

Great Britain September 1, 1960 (30 241)

Starch-based substances that are waterproof by adding thermosetting amine-formaldehyde condensates were made to glue together.

The object of the invention is to provide a method for producing ink-resistant and highly moisture-resistant Papers made from synthetic fibers and possibly cellulose fibers using amine-formaldehyde precondensates, the porosity of the papers obtained should be maintained so that they are subsequently impregnated can.

The invention is based on the knowledge that particularly valuable paper products are obtained, if an agent is added to the fiber suspension or paper pulp, which is applied for impregnation Mixed polyamide cross-linked. For this purpose, cation-active ones have been drawn up onto the fiber Melamine-formaldehyde precondensates proved to be particularly suitable.

The method according to the invention is characterized in that an aqueous alcoholic solution of a binary mixed polyamide is used as the impregnation solution from hexamethylenediamonium adipate and ε-Αηήη-caprolactam or a ternary mixed polyamide of the above is used with co-aminoundecanoic acid and a known amine-formaldehyde precondensate, in particular a cationic trimethylolmelamine already incorporated into the pulp as a crosslinking agent for the polyamide binder will.

609 608/336

3 4

The amine-formaldehyde precondensate containing has been proposed. So is the Swiss

aqueous dispersion of the fibers can be described in a minor patent specification 267,963 a method at

Amount of a water-soluble salt of a polyvalent one that can be obtained by layering it on top of one another

Metal, e.g. B. aluminum sulfate, can be added. flat, fibrous structure and subsequent binding

The high molecular weight, linear mixed polyamide is formed into layered bodies by means of dissolved mixed polyamides expediently reaches an aqueous-alcoholic solution, which proves itself to be an insulating and material solution to use. The solution can turn around. From the description of this decay a crosslinking substance and / or a driving can not be deduced that with the substrate and the mixed polyamide chemically through the impregnation provided according to the invention contain reactive water repellant. io of made of fiber material and crosslinking ais Man-made fibers come from sheets or webs of papers and man-made fibers preferably with a titer of 1.5 to 3 den and 2 to can produce paper-like structures which the 4 mm cutting length and / or synthetic fibers with conventional products in terms of flexibility, a titer of 1.5 to 3 denier and 3 to 6 mm cut-fold resistance, optionally also wet strength length into consideration, which with usual, with the paper 15 and the like, surpass.

production used paper fibers, such as Ha- After the method according to the invention can

the, bleached or unbleached pulp, etc., from natural, artificial and synthetic fibers

can be mixed. Papers consisting of or mixtures of these fibers are preferably used

Mixtures of 20 to 80 percent by weight of chemical and paper-like products with excellent

fibers with 80 to 20 percent by weight of the 20 mentioned strength properties can be achieved without

Paper fibers used. the porosity is substantially impaired.

The mixed polyamides, which are used for the subsequent In the fiber suspension as a crosslinking agent Treatment of the dried sheet can be used for the mixing applied by impregnation, should have good solubility in aqueous alcohol, polyamide with particular advantage on the fiber Colorlessness. and above all stability and a low tendency to gelling cationic melamine-formaldehyde have in their solutions. Such precondensate, if necessary in the presence of a Mixed polyamides have a good film formation - small amount of aluminum sulfate, used, fortune and melt at relatively This precondensate is z. B. by resolving low temperatures. Trimethylolamine in water, addition of ant

The below-mentioned reduced viscosity 30 acid to this solution and maturing for several hours

corresponds to the formula for bluish opalescence. Such a one

I _n η solution is stable for 12 to 14 hours.

^ -, The networking of the substrate with the mixed

^c polyamide is made with the application of heat and

measured on a solution of the mixed polyamide of 35, optionally under pressure. This can be a minor

the concentration c = 0.2 g mixed polyamide per 100 ml portion of a catalyst, consisting of a water-

Solution in 93.7% H ₂ SO ₄ at 20 ⁰ C. soluble salt of a polyvalent, in the aqueous

In the method according to the invention, such alcoholic solutions are soluble metal cations, the

Mixed polyamides advantageous, which by polymer when exposed to higher temperatures during the

sation of a mixture of a salt from a diamine 40 hot-pressing developed acidic properties, such as

and a dicarboxylic acid with a lactam of e.g. B. aluminum sulfate, aluminum or zinc nitrate,

ω-aminocarboxylic acid and / or with an amino can be added.

carboxylic acid have been produced. For example, to further improve the wet strength or binary polyamides made of hexamethylene are suitable. diammonium adipate and ε-aminocaprolactam internal crosslinking substance, such as. 1.6 hexamethylene half the limits of 35 to 45 percent by weight of N, N'-bis (ethylene urea) or a formaldehyde-hexamethylenediammonium adipate and 65 to 55 donors, and / or one also with the substrate weight percent e-aminocaprolactam. For the manufacture and the mixed polyamide chemically reactive ternary mixed polyamides can, for example, micro-water repellants, such as octadecylethylene urea, 10 to 20 percent by weight ω-amino 50 of the impregnation solution are added. Such undecanoic acid, 40 to 30 percent by weight of hexa additives must be mixed with the dissolved polyamide methylenediammonium adipate and 50 percent by weight be compatible, d. i.e., they must not consist of the mixed ε-aminocaprolactam be used. Such polyamide solutions fail or are not inactivated. Mixed polyamides have a reduced viscosity from additions of acidic catalysts when imines 1.10 to 1.30. They melt depending on the mix 55 are present, inexpedient, since otherwise the ethylene ratio between 165 and 185 ° C and imide derivatives are released from aqueous-alcoholic solutions 60 ° C, after previous swelling in case of falling or being inactivated.

Room temperature, in 67% strength aqueous ethanol ^he n The use of Äthylenimmverbindung is methanol or to 8 to 12% solutions. This is known per se. According to the German patent specification solutions are clear and viscous, they gel even after 60 880 740 fibrous materials, such as. B. papers from standing for several days not. Solutions of 10% by weight of 100% bleached sulphite pulp or of _ 100% percent in 95% alcohol, on the other hand, gel for a few hours after unbleached pulp with solutions of ethylene. The treated imine derivatives from a 7.5% solution. These papers are cast in films that are clear, tough, and stretchable; the usual way on the drying cylinder at 100 ° C films show tear lengths of 1.7 to 2.5 km at break 65 dried,
elongations of 150 to 300% ■ In the method according to the invention

The use of mixed polyamides as binders, on the other hand, from mixtures of synthetic and / or

The agent for porous, fibrous bodies has been artificial fibers and cellulose fibers with additives

an amine-formaldehyde precondensate produced Papers with aqueous-alcoholic solutions of a mixed polyamide, optionally with the addition of a Water repellant, such as octadecylethylene urea, treated in the presence of ethylene imine derivatives, dried and optionally pressed at a higher temperature.

The invention is explained in more detail below with the aid of examples.

example 1

650 g (dry weight) of bleached sulfate cellulose were in a small jar in 251 of water during Beat with a high speed mixer for 23 minutes. In a second vessel, 475 g (dry weight) bleached spruce sulphite cellulose and 475 g (dry weight) bleached aspen sulphite cellulose in 75 liters of water Whipped for half an hour and ground for 1 hour. Then the sulfate cellulose suspension was used first to the spruce and aspen sulphite cellulose suspension and finally 400 g (dry weight) in 201 Water pre-swollen fibers of polyhexamethylene adipamide with a titer of 3 den and a cut length of 6 mm was added. The combined suspensions were diluted with water to a total volume of 2001 topped up and the whole thing with 62 g of alum (15% strength aqueous solution) and with a solution of a melamine-formaldehyde precondensate offset. To prepare this solution, 60 g of trimethylolmelamine in 750 ml of water and 15 ml of formic acid were added Stirring dissolved; the solution was left to stand until a bluish opalescence appeared, with Water made up to 21 and then added to the fiber suspension.

The pH of the aqueous suspension in the inlet box of the paper machine was between 5 and 6. A paper web was formed with the suspension on a Fourdrinier machine and this was dried. The setting of the paper machine was such that a paper with a weight of 70 to 75 g / m ² and an average thickness of 0.19 mm was formed.

Sheets of the paper produced in this way were treated with an 11% by weight solution in 67% strength ethanol of a mixed polyamide which was produced from 40% by weight of hexamethylene diammonium adipate and 60% by weight of ε-aminocaprolactam and which had a reduced viscosity of 1.18 and a melting point of 180 ^° C. was impregnated, dried and pressed at 18O ⁰ C.

The paper treated in this way had a relative wet strength of 40% at 6700 m dry tear length (MR). A product prepared under otherwise identical conditions, but without the content of Trimethylolmelaminvorkondensat impregnated, dried and pressed at 18O ⁰ C Comparison paper showed a relative wet strength of 21% with an average breaking length (MR) of 6050 m dry.

Example 2

Sheets of paper produced in the same way as in Example 1 and not yet impregnated were made with a solution of 11 percent by weight of the mixed polyamide used in Example 1 40 percent by weight of AH salt / 60 percent by weight of e-aminocaprolactam (reduced viscosity = 1.18),

ao 1.5 percent by weight 1,6-hexamethylene-N, N'-bis- (ethylene urea) and 0.75 percent by weight octadecylethylene urea impregnated in 67% aqueous ethanol and placed on a steam-heated cylinder dried. The dried paper had a relative wet strength of 44% at 6000 m tear length dry (MR) on. One under otherwise identical conditions, but without melamine-formaldehyde precondensate Impregnated and dried comparison paper produced showed a relative wet strength of ' 24% dry at 6350 m tear length (MR).

Example3

One paper produced according to Example 1 with and without a cationic trimethylolmelamine precondensate (referred to as "precondensate" for short) and not yet impregnated was treated with a solution of 11 percent by weight of the mixed polyamide used in Example 1 consisting of 40 percent by weight hexamethylene diammonium adipate / 60 percent by weight ε-aminocaprolactam (reduced viscosity = 1.18) and 0.75 percent by weight of pctadecylethylene urea impregnated in 67% aqueous ethanol. Each one of these samples was dried on a steam-heated cylinder and a second sample additionally pressed at 180 ⁰ C. The properties of these papers are given in Table I.

Table I.

Without pre-condensate
Tear length

km
dry I wet

Wet strength with precondensate
Tear length

km
dry I wet

Wet strength

% Increase in wet strength **

Dried
Hot pressed

6.5
6.0

1.55
1.9

25th
32 5.8 5.7

2.3 2.7

40.5
47.1

* Tear length wet in% of the tear length dry.

% Wet strength »with precondensate« · 100 ** wet strength »with precondensate« =

% Wet strength »without precondensate«

- 100.

61.9 46.3

Example 4

With 800 g (dry weight) pre-ground, bleached sulfate cellulose and 400 g (dry weight) Pre-ground, bleached sulfite cellulose from aspen wood was made into a suspension in 100 liters of water. 800 g (dry weight) of polyhexamethylene adipamide fibers pre-swollen in 40 liters of water were added to this suspension with a titer of 2 den and a cut length of 4 mm were added. Then it was topped up with water to 2001 and the whole thing with 62 g of alum (15% strength aqueous solution) and with a solution of a melamine-formaldehyde precondensate offset. To make this solution, 40 g

Trimethylolmelamine in 500 ml of water and 10 ml Formic acid dissolved with stirring, the solution was until the appearance of a bluish opalescence left to stand, made up to 21 with water and then added to the fiber suspension.

Of two-dried, not yet impregnated sheets of paper produced in this way was a sheet with a 10% igea solution of the copolyamide used in Example 1 from 40 weight percent hexamethylene diammonium adipate / 60 weight percent ε-aminocaprolactam (F. 18O ⁰ C, reduced viscosity = 1.18) in 67% ethanol and the other sheet with an 8.75% solution of a mixed polyamide of 10 percent by weight ω-aminoundecanoic acid / 40 percent by weight hexamethylene diammonium adipate / 50 percent by weight ε-aminocaprolactam (F. 168 ⁰ C, reduced viscosity = 1 , 30) impregnated in 67% aqueous ethanol. The impregnated sheets were dried on a steam heated drying cylinder and pressed at 165 ⁰ C.

The properties of these papers can be seen from Table II. The binary 40: 60-copolyamide of melting point 180 ⁰ C in the table II A, the ternary 10: designated 50-copolyamide of melting point 168 ° C and B: 40th

Tear length
dry
km Extensibility
dry
% Table II Extensibility
wet
% Wet strength
7o * Tear strength
_g ** Mixed polyamide 4.63
5.08 7.3
10.1 Tear length
wet
km 8.1
11.2 37.0
40.0 244
234 * "" A
"B. 1.72
2.02

* Tear length wet in% of the tear length dry. ** Elmendorf tear strength, MR (machine direction) corrected to a weight per square meter of 100 g.

The comparison of the table values shows that by impregnating with the ternary mixed polyamide B, papers can be produced that are different from the with the binary mixed polyamide A impregnated papers have a higher wet strength and a slightly have lower tear strength.

During 24 hours at 20 ⁰ C conditioned papers showed after lstündigem immersion in water of 20 ⁰ C, an increase in elongation to (+) 0.156% in the machine direction and (+) 1,732% in the transverse direction and, after further conditioning for 24 hours at 20 ⁰ C a shrinkage of (-) 0.314% in the machine direction or (-) 0.227% in the transverse direction.

The papers can be used on the normal and joiner's calender as well as on the Gaufrage calender processing and pleating.

Example 5

The same procedure as in Example 4 was used to produce a paper from an aqueous suspension containing 400 g (dry weight) of pre-ground rags, 1600 g (dry weight) of viscose fibers swollen in water with a titer of 1.5 denier and a cut length of 4 mm , 62 g of alum and 60 g of trimethylol melamine. The dried, not yet impregnated paper was treated with a solution of 10 weight percent of the described in Example 1 copolyamide from 40 weight percent hexamethylene diammonium adipate / 60 weight percent ε-aminocaprolactam in 67% igern aqueous ethanol, was dried on the steam-heated drying cylinder, and pressed at 170 ⁰ C. The paper treated in this way had a relative wet strength of 45% at a dry tear length of 5420 m.

Example 6

The same procedure as in Example 4 was followed to produce a paper from an aqueous suspension, the 400 g (dry weight) pre-ground rags, 1000 g (dry weight) pre-swollen in water Viscose fibers with a titer of 1.5 denier and a cut length of 4 mm, 600 g (dry weight) in Water pre-swollen fibers of polyhexamethylene adipamide with a titer of 2 denier and a cut length of 4 mm, 62 g of alum and 60 g of trimethylol melamine contained.

The dried, not yet impregnated paper was with a solution of 10 percent by weight of the in Example 1 described mixed polyamides from 40 percent by weight. Hexamethylene diammonium adipate / 60 Percent by weight ε-aminocaprolactam in 67% aqueous ethynol treated on the dried steam-heated drying cylinder and pressed at 170 ° C. This paper exhibited relative wet strength of 52% with a dry tearing length of 5000 m.

Example 7

Paper produced according to Examples 5 and 6 but not yet impregnated was made with that in Example 3 described solution of a mixed polyamide of 40 weight percent hexamethylene diammonium adipate / 60 percent by weight ε-aminocaprolactam and 0.75 percent by weight octadecylethylene urea in

Treated 67% aqueous ethanol, dried and pressed at 170 ° C.

Paper samples of the papers obtained in this way and of papers made by the method according to the Examples 2 and 3 were prepared, were each for 4 hours in water, 4% hydrochloric acid, 4% sodium hydroxide solution and immersed in organic solvents such as benzene, alcohol and trichlorethylene. The immersion samples remained resistant to these liquids; they let themselves be taken after drying Write on ink and Indian ink without running.

Claims (3)

Patent claims: 1. A process for the production of paper consisting at least partially of man-made fibers, in which paper made from an aqueous suspension of the fiber material with a polyamide binder solution soaked and hot, optionally dried under pressure, thereby characterized in that (a) an aqueous-alcoholic solution of a binary as impregnation solution Mixed polyamide from hexamethylene diammonium adipate and ε-aminocaprolactam or a ternary one Mixed polyamide of the above is used with co-aminoundecanoic acid and (b) an amine-formaldehyde precondensate known per se, in particular a cation-active trimethylolmelamine, is already incorporated into the pulp as a crosslinking agent for the polyamide binder. 2. The method according to claim 1, characterized in that a fiber suspension is used which additionally contains a small amount of a water-soluble salt of polyvalent metals, z. B. aluminum sulfate contains. 10 3. The method according to claim 1 or 2, characterized in that the impregnation solution is low Amount of a crosslinking substance such as a bifunctional ethyleneimine derivative or a Formaldehyde donor and / or a crosslinking water repellent, such as octadecylethylene urea, contains. Considered publications:
German Patent No. 965 864;
U.S. Patent No. 2,629,699;
H ο uwi η k, »Chemistry and Technology
Kunststoffe ", Vol. 2, 3rd edition, 1956, p. 355;
TAPPI, 41 (1958), pp. 430 to 433;
AlIg. Papierrundschau (1956), no. 10, pp. 478 to 480. 609 608/336 7.66 © Bundesdruckerei Berlin