DE2315283C3 - Color-stabilized homopolymers or copolymers of acrylonitrile - Google Patents

Description

Il

MOP-

R O

I I

-C P-OM

(D '5

OM OH OM

in which M is a hydrogen atom, a sodium, lithium and / or potassium atom and R is a lower alkyl radical with 1 to 11 carbon atoms, a phenyl radical and / or an alkylphenyl radical with up to 8 Carbon atoms is included.

2. Color-stabilized homopolymers or copolymers of acrylonitrile according to Claim 1, characterized characterized in that they contain 1-hydroxy-ethane-1.l-diphosphonic acid as the organophosphorus compound.

3. Process for the production of color-stabilized homo- or copolymers of acrylonitrile, characterized in that the polymer with an organophosphorus compound of the general Formula (I) is brought into contact in such a way that the spun polymer through a bath which contains the organophosphorus compound and that the threads are then dried will.

40

The invention relates to color-stabilized homopolymers or copolymers of acrylonitrile, the copolymers contain at least 60 percent by weight of acrylonitrile as polymerized units.

Acrylonitrile homopolymers and copolymers containing at least 60 percent by weight acrylonitrile, are usually insoluble in the usual solvents and even in special solvents the Dissolution rate slow at room temperature. To find a solution, use the general heat, which often leads to a dark coloration of the polymer solution. Such a dark color which occurs even more if the solution is left to stand for a long time is undesirable because it causes the polymer is also colored dark. It is believed that the presence of certain substances and im special ions such as iron, copper and manganese ions in traces for this dark color are responsible. By using the commonly used solvent dimethylacetamide the darkening can be further intensified. It is also believed that impurities in the solvent which also cause the darkening. Regardless of the cause of this The products made from them have undesirable properties when they are dark in color. Up to now, attempts have been made to to solve this problem with the help of organic additives. So were certain optical brighteners Spinning solutions added The factors that cause the discoloration are not eliminated and the color stabilization problem has not really been solved. In addition, various methods have been made using sequestering agents in the washing process designed around this way the Remove metal ions. This is how ethylenediaminetetraacetic acid became added to the spinning solution to remove the metal ions Disadvantages that the respective organic acid must be removed by thorough washing.

There is therefore a great need for color-stabilized ones Homopolymers or copolymers of acrylonitrile which, in particular, are no longer dark in color.

The invention thus relates to homopolymers or copolymers of acrylonitrile, the copolymers contain at least 60 percent by weight of acrylonitrile polymerized, which is characterized are that the polymers as a color stabilizer 0.01 to 5 percent by weight, based on the weight of the Polymerisates, an organophosphorus compound of the general formula

O R

MO-P C P-OM

! I I

OM OH OM

in which M is a hydrogen atom, a sodium, lithium and / or potassium atom and R is a lower alkyl radical with 1 to 11 carbon atoms, a phenyl radical and / or a It contains alkylphenyl radicals with up to 8 carbon atoms.

Color-stabilized homopolymers or copolymers of acrylonitrile, in which as Organophosphorus compound l-hydroxy-ethane-l-diphosphonic acid is used.

The invention also relates to a process for producing color-stabilized homopolymers or copolymers of acrylonitrile.

The method is characterized in that the polymer with an organophosphorus compound of general formula (I) is brought into contact in such a way that the spun polymer through a bath is passed which contains the organophosphorus compound and then the threads are dried will.

Surprisingly, it has now been found that the polymers according to the invention are practically color-stable in that their solutions do not discolour even when left to stand for a long time or when heated, so that the molded articles produced therefrom, in particular fibers, practically no longer discolor.

The color-stabilized acrylonitrile polymers can also be prepared in such a way that the Organophosphorus compound and the freshly prepared polymers, as long as they are still in a slurry, be mixed.

The polymer treated in this way is then isolated using customary methods. You can go further the organophosphorus compound to the polymer solvent prior to addition to the polymer admit, because that way any color that turns out

could develop, for example by heating, is inhibited at the time of their formation.

As a solvent for dissolving the acrylonitrile polymers come N, N-dimethylformamide, NJM-dimethylacetamide, Ethylene carbonate, dimethyl sulfoxide or 55% aqueous sodium thiocyanate can be considered

Suitable organophosphorus compounds are:

HO-P-

CH ₃ O

I I

-C P-OH

OH OH OH

CH ₃
O CH ₂ O

!! I I!

HO-P C P-OH

I I I

OH OH OH

0 CH, O

Il I "Il

Na ⁺ O PC PO Na ⁺

1 I I

Na ⁺ ~ O OH O ~ Na ⁺

QH ₅
O CH, O

HO-P-

-P-OH

OH OH OH

The polyacrylonitrile or acrylonitrile copolymer may also contain 2 to 50% other polymers. The acrylonitrile content in the mixture should, however also make up at least 60 percent by weight. Acrylonitrile-containing polymers with less than 60 Weight percent acrylonitrile is not suitable for the formation of fibers, films, lacquers.

For example, the polymer can be a copolymer of 60 to 98% acrylonitrile and 2 to 40% other monomers that are copolymerizable with acrylonitrile. Suitable other monomers are

Acrylic, chloroacrylic and methacrylic acids,
Acrylates, such as methyl acrylate, methyl methacrylate,
jJ-chloroethyl methacrylate and the corresponding
Esters of acrylic and chloroacrylic acids,
Vinyl chloride, vinyl bromide, vinylidene chloride,
1 -Chlor-1 -bromoethylene, methacrylonitrile, acrylamide and methacrylamide, «-chloroacrylamide or their monoalkyl substitution products,
Methyl vinyl ketone, vinyl carboxylates, such as
Vinyl acetate, vinyl chloroacetate, vinyl propionate and vinyl stearate, methylenemalonic acid ester,
Itaconic acid and itacondimethyl ester,
N-vinyl carbazole, vinyl furan, vinyl sulfonic acid,
Sodium methallyl sulfonate, sodium styrene sulfonate, sodium p-sulfophenylmethallyl ether,
Ethylene - «, j3-dicarboxylic acids or their derivatives,
such as diethyl citraconate, diethyl mesaconate, styrene,
Vinyl naphthalene.

The polymer can also be a multicomponent polymer, for example a polymer which by polymerizing acrylonitrile and two or more other monomers as mentioned above can be obtained.

The polymers can be prepared by any conventional polymerization process, such as, for example by block polymerisation, solution polymerisation or emulsion polymerisation. The suspension polymerization process but is preferred.

ίο The use of the organophosphorus compounds described leads to an improvement in the color properties in the solutions and the moldings produced from them, in particular fibers.
The tests used in the examples

ι S for the color stability of the fibers consist of measurements of the purity (P), the brightness (Y) and the dominant wavelength (DWL), which result from the spectra. The measurement method used here is described as the "Standard Observer and Coordinate System" in the Handbook of Colorimetry. Although the complete specification of the fiber color requires the combination of the purity, the lightness and the dominant wavelength, it is possible to qualify the color of a number of fibers by the numerical values of the lightness and purity alone, provided that the dominant wavelength remains practically the same. This applies to the examples given here, since the dominant wavelength in the control and the test samples does not differ by more than 2 nm. Higher brightness values (Y) and / or lower purity values (P) mean an improvement in the degree of fiber whiteness. The fiber brightness and the purity values were determined by means of various samples under initial conditions and after heating at 145 ° C. for 25 minutes in a forced air oven. A completely white fiber would correspond to a purity value of zero and a brightness of 100.

The polymers of the present invention have many advantages. For example, those from the Products made from polymer solutions are free of disruptive colorations. The production of the polymer solutions can also be carried out with warming without risk. The polymer solutions can also be left to stand for a long time, whereby they remain color-free.

In addition, the organophosphorus compounds are readily available.

The following examples illustrate the invention. Parts, proportions and percentages are parts by weight, Weight ratios and percentages by weight, unless otherwise specified.

example 1

A discontinuous one initiated with free radicals

Suspension polymer was used to produce a multi-component polymer that is 66 percent by weight Acrylonitrile, 20 weight percent vinylidene chloride, 11 weight percent vinyl bromide, 1 weight percent Styrene and 2 percent by weight sodium p-sulfophenylmethallyl ether contained, carried out. After removing the unreacted monomers by means of volatilization the aqueous polymer slurry was transferred to a container for temporary storage. the Polymer sludge was obtained by adding 0.2 percent by weight of 1-hydroxyethane-1,1-diphosphonic acid, based on the polymer present to which

Container treated The contents of the container were mixed thoroughly by stirring. The average residence time and the storage temperature of the polymer was about 10 hours at 50 ° C In the following work processes was the treated polymer was isolated in the usual manner by filtration, washed with deionized water, dried, gemanlen and in storage containers transferred to the specific viscosity {η ^) of the isolated polymer was 0.16, measured at 25 ° C. in a concentration of ro 0.1 gm / dl in dimethylformamide which contained 0.2% lithium chloride

The color properties of the fibers spun from the polymer treated with l-hydroxyethane-l, l-diphosphonic acid were compared with the color properties of fibers which had remained untreated but otherwise had the same composition. To obtain such fibers, portions of the treated and untreated polymers were used separately to prepare spinning solutions containing 23 percent by weight polymer in dimethylacetamide. The spinning solutions were stirred at 60 to 70 ° C for 30 to 40 minutes before spinning. These were then spun into a mixture of dimethylacetamide and water (40:60 weight ratio) at about 50 ° C. The threads obtained in this way were orientated to 5.5 times their original length by means of cascade washing ^{and passed over heated bobbins at about 130 ° C. The fibers were tempered by steam treatment at 1.4 kg / cm 2. The tempered denier was 3.0} . The fiber color was determined for brightness and purity at the beginning and after heating for 25 minutes at 145 ° C. in an air-circulating oven. The values obtained in Example 1 are given in Table 1 below. The higher the brightness value and / or the lower the purity value, the better the fiber color.

example

An acrylic polymer was produced analogously to Example 1. The polymer had the same composition and the same specific viscosity as that of Example 1. The polymer was in conventional Way, d. H. without the organophosphorus compound being added, isolated and stored.

Four spinning solutions were prepared using dimethylacetamide as solvent, each with 23% by weight in the multicomponent acrylic polymer. The first spinning solution was used as a comparison solution, the other spinning solutions were 0.05, 0.10 and 0.15% by weight, based on weight of the polymer, 1-hydroxyethane-1, l-diphosphonic acid was added. 1 percent by weight of antimony trioxide (SbjCh), based on the polymer, was added to all spinning solutions, including the comparison solution. The spinning solutions were stirred at 60 to 70 ° C for 30 to 40 minutes before being spun. The spinning solutions were spun into a mixture of dimethylacetamide and water (55:45 weight ratio) at about 30 ° C. The threads obtained in this way were orientated to 5.5 times their original length with the aid of cascade washing and passed over heated bobbins at 130.degree. The fiber was annealed by steam treatment at 1.75 kg / cm ^2. The annealed denier was 3.0. The degree of lightness and purity of the fibers at the beginning and after heating for 25 minutes at 145 ° C. in an air-circulating oven is given in Table I.

example

A conventional free radical initiated, continuous polymerization process has been used for Production of a polymer used, the 88 percent by weight acrylonitrile, 7 percent by weight vinyl acetate and contained 5 weight percent vinyl bromide. The polymer became from the aqueous polymer sludge isolated by filtration, washed with deionized water, dried, ground and stored. The specific weight of the isolated polymer was 0.15, measured at a concentration of 0.1 g / dl in dimethylformamide.

Three spinning solutions were prepared using dimethylacetamide as the solvent, each containing 25 percent by weight acrylonitrile-vinyl acetate-vinyl bromide terpolymer. The first spinning solution was used as a comparison solution and 0.10 and 0.20 percent by weight, based on the polymer, of 1-hydroxyethane-1,1-diphosphonic acid were added to the other spinning solutions. The spinning solutions were stirred for 20 minutes before spinning at 60 to 70 ° C. They are spun in a mixture of dimethylacetamide and water (60:40 weight ratio) at about 30 ° C. The threads obtained in this way were oriented in a cascade wash to 6 times their original length and passed over heated bobbins at 130.degree. The fiber was annealed by steam treatment at 2.45 kg / cm ^2. The annealed denier was 16.5. The degree of lightness and purity of the fibers was determined at the beginning and after heating for 25 minutes at 145 ° C. in an air circulation oven; the values obtained are shown in Table I.

example

A conventional free radical initiated, aqueous polymer sludge isolated by filtration,

continuous polymerization process was washed to 65 with deionized water, dried,

Used to produce a polymer that was ground in 93 and stored. The specific viscosity of the

Percent by weight of acrylonitrile and 7 percent by weight of isolated polymer was 0.15, measured on a

Contained vinyl acetate. The polymer was made from the concentration of 0.1 u / dl in dimethylformamide.

Four spinning solutions were prepared using dimethylacetamide as the solvent, each containing 25 percent by weight of acrylonitrile-vinyl acetate copolymer the polymer, l-hydroxyethan-II-diphosphonic acid added. The spinning solutions were ^{stirred for 20 minutes at 60 to 70 °} C. before they were spun. The spinning solutions were in a mixture of dimethylacetamide and water (57: 43 weight ratio) spun at about 4O ⁰ C. The filaments thus obtained were analyzed using cascade washing to 5.3 times their original length and orientierungsverstreckt pass through heated coils at about 130 ⁰ C the fibers were by steaming at 2.45 kg / cm ² annealed, the annealed denier was 3.0 . The degree of lightness and purity of the fibers at the beginning and after heating for 25 minutes at 145 ° C. in an air-circulating oven is given in Table I.

Table I.

Example 1 Example 2

Example 3 Example 4

Weight Fiber color values • Pure after heating Pure percent at the start Ness Ness Color 5.9 Bright 17.9 suabilizer Holy- 5.6 speed 16.0 speed 103 72.4 18.9 comparison 88.2 7.8 76.2 15.9 0.20 89.4 7.1 73.0 14.3 comparison 853 7.0 77.9 14.9 0.05 89.5 10.5 79.8 15.1 0.10 90.6 8.6 79.4 13.6 0.15 903 6.9 75.3 12.6 comparison 82.6 5.5 77.5 9.5 1 (1.10 85.5 4.8 79.7 8.1 0 £ 0 87.8 4.8 84.8 8.2 comparison 89.6 5.1 87.1 7.9 ΙΪ, 05 91.8 86.8 0.10 91.1 86.3 0.20 91.1

Claims (1)

Patent claims: 1. Color-stabilized homopolymers or copolymers of acrylonitrile, the copolymers containing at least 60 percent by weight of acrylonitrile Uymerized included, characterized in that that the polymers as color stabilizers ■ tor 0.01 to 5 percent by weight, based on the Mixture of the polymer, an organophosphorus compound of the general formula