DE1925228A1 - Process for the production of a pigment concentrate - Google Patents

Description

Process for the production of a pigment concentrate

The present invention "relates to a method of manufacture Clay pigment concentrates and in particular an improved one Dispersion of pigments in acrylonitrile polymers. e.g. cheese.

In the conventional dyeing of fibers, a colorless strand is passed through a dye bath to give the outer surface color. In a new development in the field of synthetic fibers, especially acrylonitrile polymers, an internal dyeing process is used, the so-called "spin dyeing" process , at. This method consists in that maji the pigment in the "spinning liquid", ie the solution of the acrylonitrile polymer, which is usually a polymer; concentration of 15 to 30 $, dispersed from which the fiber is spun. In such a method, the degree of pigment dispersion in the liquid determines the uniform, permeable coloration of the fiber and also influences its physical properties. ₍

The dry pigment can be incorporated directly into the spinning liquid by rapid mixing, but this leaves it alone

909ÖS0 / U35

■; BATH ORIGINAL

Procedure left a lot to be desired. Cure a small part of the Pigment is properly dispersed, while the reads agglomerate "forms, and a large part of the pigment is separated off, if the liquid is filtered before spinning. This often results in fibers of uneven color and inferior quality physical properties obtained.

A further process is used to predisperse dv3 pigment or ground in a solvent, often using the same solvent to make the liquid, or the solvent is at least compatible therewith. However, these solvent dispersions are inconsistent, flocculate quickly and settle. There was also> further flocculation will take place when introduced into the dope, and in some ± igment-solvent systems finds a pigment recrystallizer. instead, which results in a change in the color tone »Des i-polymer becomes sometimes the pigment-solvent dispersion before the introduction same in the spinning solution added to the dispersion to stabilize, however, this also has additional measures only led to indifferent results

The most successful attempt so far has been in the manufacture of Passed dry concentrates of the highly dispersed pigment in the polymer. Such concentrates can be used for a long time Periods without pigment agglomeration are allowed In use, the concentrate is combined with the solvent and subjected to an intensive church, whereby the polymer is dissolved and the pigment is present as a fine dispersion »The resulting liquid is then poured into the Spinning fluid introduced.

Corresponding processes for producing such solid color concentrates vary depending on the polymer and, to some extent, the type of pigment used. Cellulose acetate is popular because of its easy workability and its favorable solubility in the preferred solvents for the spin fluid largely than

909850/1435 "" -; -

IAD ORfGfMAL '

Medium used for pigment concentrates. For example be Pigment concentrates by grinding the pigment with cellulose ' ■ acetate produced in a heated two-roll mill or in another mixing device, e.g. a Baker-Perkins mixer, and the solid obtained is then comminuted by grinding. The pigment and the polymer can also be used in a solvent, e.g. acetone, using a ball mill, the solvent then evaporating and the concentrate further into lumps or powder is ground.

however, it was found that Celluloseacetatpigmentkonzentra- te for dyeing acrylonitrile polymer are undesirable · The two polymers are incompatible in the dry state, in general, so that a precipitation or a non-massive distribution of the cellulose acetate and of the dye within the Paser _s often occurs resulting in * a fiber with poor shine,

A pigment concentrate in the acrylonitrile polymer has therefore proven advantageous to achieve optimal results to be used for dyeing acrylonitrile fibers. The production of such concentrates is, however, more difficult than When using cellulose acetate, aeryl nitrile polymers are more heat sensitive, and suitable solvents are due to Their high boiling points are difficult to completely remove by evaporation.

In the past, for example, in the USA patent 3_215 663 proposed a pigment concentrate from a dispersion of pigment particles in a polymer solution by addition a non-solvent diluent to co-precipitate. The concentrates obtained by this process, while useful, provide for acrylonitrile polymers not the full color value, and besides, they tend to be out of the The following also result in renewed pigment agglomeration:

9 0-9 8 5 0 / U 3 5

As stated above, it was found to be a significant advantage to use acrylonitrile polymers as the pigment medium, where the concentrate is intended for use in dyeing acrylonitrile polymers. Unfortunately, disperse however, most pigments even in the solvents preferred for acrylonitrile polymers, e.g. in dimethyl., sulfoxide, dimethylformamide and dirnethylacetamide, only weak. Therefore, the co-precipitated pigment concentrates that are precipitated in a mixture of acrylonitrile polymer solution deliver due to the incomplete dispersion of the pigments not the full coloring power " Attempts to obtain better pigment dispersion by incorporating conventional surfactants, e.g. Cationic dispersants, in achieving pigment dispersion in acrylonitrile polymer solutions, generally result zii significant foaming problems, creating another difficulty or one problem through the other ' is replaced.

Another advance is achieved by a method described in U.S. Patent 3,361,705. Here the pigment is dissolved in the polymer solution with the aid of a solubilizer, then the pigment and the polymer are precipitated as a mixture by adding a non-dissolving diluent. Such a process makes a particularly fine pigment dispersion required and the ^w in this color concentrates else preserved lead to a substantially improved color depth for acrylonitrile.

It has been found, however, that a number of important classes of pigment in solvents for acrylonitrile polymers even where high concentrations of the solubilizer are used show an extremely low solubility. this applies particularly to the pigments of the disazo, quinacridone and Phthalocyanine class and also for pigments of the anthraquinone, Pyrazolone and thictodigoid classes too. Therefore, the above listed processes for the production of concentrates

909850 / 1Λ 35

■ - 5 -

These pigments used in acrylonitrile polymers are very good large volumes of solvent required, resulting in additional Cost led

A solution has now been found to these various problems, which in a new process for the manufacture of a. Pigment concentrate is embodied, According to this process, an intimate suspension of the pigment in the acrylonitrile polymer solution is produced with the aid of a very low concentration of the dissolved base of about 1 to 10% by weight, based on the pigment Method extremely fine pigment dispersions can be easily obtained without it being necessary ^{to dissolve the 1} pigment, with no flocculation problems at all. If such a suspension is brought into contact with a liquid in which the polymer and the pigment are insoluble, the contaminants precipitate together as a concentrate of finely dispersed pigment in the polymer. Such pigment concentrates are ideal for use in the spin dyeing of acrylonitrile polymers , especially for fibers, where they lead to an improved gloss, an improved transparency, and depth of the color as well as a better uniformity in color improved pigment concentrates avoided "

Such results are particularly surprising in view of the fact that in the manufacture of acrylonitrile polvene Bases are normally considered undesirable as they have been reported to promote gelling, discoloration and denaturation Favor dismantling. Neither of these problems was the only one Bases used in very low concentrations were found, instead those listed above became noticeable Benefits identified.

In a preferred embodiment of the new method

909850/1435

Suspension of the pigment in the polymer solution in a non-solvent Injected diluent, after which the pigment concentrate in the form of an easy-to-use, continuous Strand is obtained :.

The acrylonitrile polymers which can be used according to the present invention as media for the pigment concentrates according to the invention are polyacrylonitrile itself and interpolymers of acrylonitrile with other unsaturated monomers, for example with methyl methacrylate or vinyl chloride. Such interpolymers include the acrylonitrile copolymers, ie copolymers of acrylonitrile with about 15 to 60% by weight of other unsaturated monomers, as well as the copolymers of acrylonitrile with concentrations of monomers of less than 15 ° / ° A typical according to the invention The acrylonitrile polymer used consists of an interpolymer of acrylonitrile with an equal weight of vinyl chloride. For best results it is of course advisable to use the same polymer in the pigment concentrate as the fiber or other polymer that is dyed should be, exist, as this optimal compatibility, appearance and physical properties are obtained,

The solvent used can be any liquid in which the polymer can be dissolved in economical concentrations. Polar solvents are generally particularly effective, especially lower dialkyl _{sulfoxides, ζ β} Β _β dimethyl sulfoxide (DMSO), lower E "-alkyl or lower £:, ¥ - dialkylacetamides, for example dimethylacetamide (DMAc) and lower F-alkyl or lower Η , ϊΓ-Dialkylformam ^ e z. ^B · dimethylformamide (DMF) is particularly advantageous. to take the same solvent that is used in spinning of the finished fiber.

As already mentioned above, the pigments that are favored by the new process are the disazo pigments,

909Ö50 / 143S bad original *

for example benzidine OT-yellow, the quinacridones, for example quinacridone red B, the phthalocyanines, sB phthalocyanine green and blue, and the anthraquinone, pyrazolone and thioindigoid pigments. On the other hand, pigments of the monoazo and azonaphthol classes do not have the same problems and, moreover, are not generally used for coloring acrylonitrile polymers.

The percentage of pigment used in these concentrates is usually based on the total weight of polymer and Pigment, in a range of about 20 to 80 percent by weight, usually about 50 weight percent is preferred. Pigment proportions of under $ 20 are a little more diluted than is desirable while pigments that are well over $ 80 are difficult to achieve without adversely affecting the physical properties of the color concentrate. ·

Any .nase- which is soluble in the polar solvent can be used in the process according to the invention, including inorganic bases, for example sodium hydroxide, potassium hydroxide, potassium carbonate or ammonia, and organic bases, with organic amines, for example mono-, di- . and trialkylamines, and mono-, di- and Trialkylanolamine and alkylenediamines are preferred particular, mono; "thanolamin and Äthvlendiamin preferred, while the be · i - play for av ^ _e ^ v amines Dimethylaiiiin, triethylamine, Butylair in. Amy lam in, i'riäthanolamin, K-Artinoäthyläthanolamin, Diäthylesitriamiiund'Iropylendiair.in belong, all of which are readily available, '' he noted, is only a very _t: eri> .j he iasenqnteil necessary, 1- 1 Ο ^ ό, related to "ias aev / icht 'of the pigment.

At a tyi ijc-ier. iusleitungsform for the invention Processor, is it dirty, the pigment in the solvent beforehand suitable to disperse in a ball mill. At this stage the base can also be introduced, ur.d the solution cut. ' is usually the same as the

bad original 909850 / U35 ■

Dissolve the polymer and use it to spin the finished fiber * det is, for example dimethylaoetamide »It was found that the solvent is more conveniently used in such an amount that about 13-22% by weight of pigment in the solvent and a Stormer «* V-ißko @ ität of about 80-120 Cancer units, -preferably about 110, are obtained » Milling in the ball mill for about 8-16 hours gives an excellent transparent dispersion "" in which the Pigment particles generally have a "diameter" of less than 0.2 microns * When combining several pigments it is usually best to separate them before mixing to disperse in the solvent * .Instead of "the ball mill, another high-shear dispersing device can be used can be used, for example a sand mill or a Cowles dissolving vessel.

At this point it is appropriate. " the mer solution, for example in dimethylacetamide »to be added. A polymer concentration of about 20 $ causes a viscosity, which can be handled with no difficulty Third to add initially, and then half an hour or grind for an hour before adding the hest. The resulting dispersion of the pigment in the polymer base solution is relatively stable and can if kept in the ball mill until it is needed for precipitation with the non-dissolving diluent will. It is of course also possible to add the polymer directly and add it to the pigment suspension, without first preparing a separate polymer solution »The base can be added at any time prior to contact be dissolved with the non-solvent diluent.

The choice of a nonsolvent diluent or a precipitating liquid is not critical and any liquid in which the polymer and the

9098 5 0/1435 originally inspected

Substantially insoluble pigment can be used. Water is usually preferred, but other inert liquids can be used instead thereof, as for example, lower alkanol, ζ.B, methanol or ethanol, ketones ^ z ', B _e acetone, esters ,, eg ₄ Ithylaoetat or aliphatic or aromatic hydrocarbons, for example hexane, benzene or toluene *

If necessary, the non-dissolving diluent can Pigment-polymer dispersion can be added, whereby the Pigment concentrate precipitates in the form of individual particles. In this In the case, the best results are achieved when the dispersion is initially mixed with additional amounts of the polar solvent up to a total solids content of about $ 8 or less is diluted.

A preferred embodiment of the present invention causes the pigment-polymer dispersion to be extruded in the nonsolvent diluent to make the pigment concentrate as a continuous strand; to be obtained, the subsequent can be cut into the desired lengths. These Working method is particularly useful because of the complete .Relief from dust problems, caking or lumps

After redissolving in the spinning liquid or the solvent. If this process is used, it is desirable to produce a pigment concentrate that contains about 20-60 $ pigment, since the strand tends to break with higher pigment proportions. A pigment concentration of about $ 40-60 results in a non-breakable strand which can easily be cut into short pieces and is therefore particularly preferred.A total solids content in the pigment-polymer division for the extrusion process is in one range of about 13 to 25 ^ö ew * ~ $ (based on the total weight of pigment plus polymer), in a total solids content of less than about 13 $ of the strand may break and ■ »except learning of solvent consumption is unnecessarily high, while at a Content in excess of about $ 25 solids which. "Viscosity becomes excessively high. With total solids contents of approx

909 & 50 / H35

A "granular" product is obtained by this process at 8 % or less.

Before extrusion, the pigment dispersion is preferably pumped through filters which are coarse enough to allow the dispersed pigment particles to pass through. The filtered dispersion is then injected into the bath of water or other non-solvent diluent to form a gelatinous strand with a diameter, for example, about 0.16 cm. Several baths arranged one behind the other can be used, initially pressing into warm water and then into a cold water bath. The strand can now be cut into short pieces for further washing with water and methanol, before about 80 % of the volatile content is dried to below 2 ° F. During washing, the high-boiling solvent and the base are extracted from the pigment concentrate while water and methanol are removed in the drying step to obtain a dry porous concentrate of the pigment in the acrylonitrile polymer.

For use, the pigment concentrate can, for example, be dispersed in a concentration of about 15% in the spinning solvent, whereupon the polymer dissolves in a highly dispersed state, releasing the pigment. It was found that the liquid pigment dispersion obtained is stable over long periods of time and free from flake formation if it is not used until after a certain time. The dispersion is then measured into the spinning liquid, which is, for example, 25% Solution of acrylonitrile polymer in dimethyl acetamide The amount of pigment concentrate to be used will, of course, vary with the particular situation, but it is usually not necessary to add more than about T / ° pigment concentrate or the equivalent amount of about 3.5 % pigment use.

In the description above, the f-creation and

90985Q / U3S. - ^

BAD ORfGINAL

Use of pigment concentrates explained, however, lie for the expert many variations are obvious, so the dry pigment concentrate can be placed directly in the spinning solution if necessary, with stirring and heating, dispersed. Often it may be desirable to add additional pigments, such as "For example soot or titanium dioxide, as well as, if necessary, small amounts of stabilizers or other agents to be incorporated into the pigment concentrate «

According to the inventive method, an improved one is obtained Pigrnentdispersion with greater transparency, which in the various stages of manufacture dei? Pigment concentration is completely free from flocculation, i.e. in the initial dispersion before and after combining with the Polymers, as well as in the stages of using the concentrate, i.e. wen) them in the solvent or spin fluid is redispersed. Verbes: erte transparency, gloss and depth of color are in the solid pigment concentrates and what far more importantly, it is found in the colored polymer obtained as the final product.

The following examples illustrate the invention,

Example 1 ■

100 g quinacridone red

10 g of a 10% by weight solution of potassium hydroxide in methanol 4-74 g of bimethyl sulfoxide

667 g of a 15> - 'strength solution of iolyacrylonitrile homopolymer in DMSO

The l-aluminum hydroxide represented 1 # of the pigment weight. The ratio of pigment to polymeric was 1: 1, the total solids content is $ 16 of the liquid dispersion.

Pigment, Kaliuinhyiroxyd and DMSO were in a ball mill brought and dispersed for 16 hours. The mill was then opened and 1/3 of the polymer solution was added. The mill was

. 90S8EO / U3S BADOH, Q _IN AL

1B25228

closed, kept in operation for 30 minutes and switched off again ». net to add the rest of the polymer solution, then was closed-dia mill and. kept going for an hour »_ ■

The obtained liquid dispersion was placed in a pressure vessel. brought "the one" equipped with a jet head flusslerSung 'owns, d' ^ rch. which the drain under the water · »

surface in a bath takes place «The G-efäß works © unt © 2? -. ■. "■;-" nitrogen pressure, and the dispersion was pressed through the spinning nozzle in order to form strands of water in the water. and in., an ^{oven sn at 70 0} O get .ro oil © te. The dry strands were cut into short pieces of any "- .." dimension and formed the final dry surface. - .. ■ "-' . --- ._

The product became, by dissolving it in a 15 ^ igea Xtö · * ». ■ solution of polyacrylonitrile in DMSO in an amount of iron 4 g Pigment concentration ■ assessed per 100 g polyacrylonitrile *. Segos · * Several films made from this film solution (dope) showed a higher value Degree of transparency with a large color value and a bluer one Undertone of the color compared to control films, which were obtained from a pigment concentrate which, as described, but was produced without potassium hydroxide «

Example 2

100 g phthalocyanine blue pigment
397 grams of dimethylformamide
6 g of ethylenediamine

333 g of a 20% solution in DMF of an 86:14% by weight acrylonitrile; Methyl methacrylate copolymers

The ethylene diamine set 6 $> weight of the pigment is * Dae ratio of pigment to polymer was 3: 2nd The total solids content was 19.8% of the liquid dispersion. The color concentrate was made according to the procedure of the example. 1 "and had similar advantages.

909850 / U3S

«KV V

- ■ 13 -

Example 3

100 g llavanthron-G-erb ■ "-" -

647 g dimethylaoetamide.

6.67 grams of monoethanolamine

500 g 20% solution in DMAe of 50% 50% by weight acrylic «. nitril vinyl chloride polymers

The monoethanolamine represented $ 6.67 of the pigment weight ", The pigment to polymer ratio was Isi. The total solids content was $ 15.9 of the liquid dispersion, that Color concentrate was made by following the procedure of Example 1 to achieve comparable results. Results produced «" ■ /

Example 4 - '^; ..- "" - · '

100 g copper phthalocyanine green. ..

4 grams of monoethanolamine. .

389 grams of dimethylacetamide . .

166.67 g of 20% solution in DMAo ei3 | xes 86i14 Grev; .-% AcrypL-nitriltMethylmethacrylat-Mi ^ chpdlymeren

The monoethanol represented 4% of the pigment weight »The ratio of pigment to polymer was 3ί1> The total solids content represented 20.1 ° β> of the liquid dispersion» The pigment was in DMAc and monoethanolamine. Dispersed for 16 hours in a ball mill. The polymer solution was then placed in the ball mill as described in Example 1. 1007 g of DMAc were added to the bottom. The mill was rotated until a uniform dispersion was obtained At this point the mixture contained a total of 8 solids and the liquid had a low viscosity. The latter was placed in a well-stirred water bath in which the pigment and the polymer precipitated together in the form of small granules. These granules were separated off by filtration, washed with water to remove DMAc, rinsed with methanol and, as described in Example 1, dried in the oven. To obtain a dry color concentrate in granular form, containing 75 1 ° pigment,

909850 / U35

Example 5

100 g disazo red

364 g of dimethyl sulfoxide

10 g monoethanolamine
2o0Ö0 g 20-form solution in DFISO of polyacrylonitrile

The monoethanolamine represented 10 ^c / o of the pigment weight »The ratio of pigment to polymers! was 1: 4 «2 total solids content was 20.1 % of the liquid dispersion. The color concentrate was processed as described in Example 1, with equivalent results being achieved»

^ example 6

100 g pyrazolone red pigment

4 g ammonium hydroxide (28-30 $ M ^ - ^ econtains) 765 g dimethylacetamide
667 g of a 15% solution in DMAc of polyacrylonitrile

NH, represented 1.5 $ of the pigment weight "The ratio of pigment to polymer was 1: 1, the total solids content represented 13 % of the liquid dispersion" The color concentrate was prepared as described in Example 1 "

Example 7 ■ · '

100 g thioindigoides red pigment

1.5g potassium carbonate
474 grams of dimethylformamide

? 667 g I5 ^ solution in DMF of 93 "7 percent _e -tigern acrylonitrile: Vinylaeetat-Mischpoiymerem

D s _a potassium carbonate presented 1,5 / ^ weight of the pigment is _e ratio of pigment to polymer was 1: 1. The total solids content was 16 % of the liquid dispersion. The concentrate was prepared as described in Example 1.

909850 / U3S

Claims (1)

PATE N- TAN.SPRING E ": Process for the production of a pigment concentrate from about 2.0-80 & ew .- ^ a disazo-j Ghinacridon- _? Phthalocyanine-, anthraquinone-, pyrazolone- or thioindigoid pigments in actylnltrilpolymeren, which was obtained by preparing an intimate suspension of the pigment in a solution of the polymer and contacting this suspension with a non-dissolving diluent for this pigment and the polymer, whereby the concentrate is precipitated * characterized in that a base is dissolved in this suspension ₉ "before it is brought into contact with the non-dissolving diluent, the base being used in a length of about 1-10 parts by weight of the pigment. 2, The method according to claim 1, characterized in that one an organic Am in, preferably monoethanolamine, as the base or ethylenediarain used, 3 «The method according to claim 1, characterized in that a dimethyl sulfoxide solution is used as the polymer solution, 4 · The method according to claim 1, characterized in that one a Κ, ίί — pimethylacetamide solution is used as the polymer solution. 3, method according to claim 1, characterized in that one as a polyether solution a ft, H-diethylformamide solution is used, 6, Method NRICH claim 1, characterized in that one _ß da.s as polyacrylonitrile polymer used, 7, the method according to claim 1, characterized in that nan as a polymer, an interpolymer of acrylonitrile with up to 60 ίΚ- \ ν .-. Ό of another unsaturated i-ionomer was used. 909850/1435 - BATH K. Procedure ri ^ ch claim 1, whereby / ^ indicates that mail Wasoer reserved as a non-dissolving diluent. 9. VerfaJiren η rich claim 1, characterized ijekennzeicnriet that the precipitation drd \ n: c] i bev / irkt, d; t: 's nan the suspension in
the non-dissolving diluent is pressed, whereby the concentrate is obtained in the form of a continuous strand; _e 1Oo method according to claim 9 »characterized in that one a suspension used that totaled about 13 "to $ 25 Contains solids. For Chase Pfimer & Co., Inc.
New York,. ~ .Y _O , V.St.A, Lawyer BATHROOM ORiGINAL- 909850 / H3S