DE1939805A1 - Process for coloring microporous polyurethane - Google Patents

Description

description to the patent application

IMONT CORPORATION 113 Avenue of the Americas, New York, "N.Y. IO36, U.S.A.

concerning

Process for coloring microporous polyurethane

The invention relates to a method for dyeing microporous polyurethane in the form of sheets or films with the help of dyes soluble in organic solvents.

There are dyeing processes for microporous or foamed polyurethane known in which either the polymer in the Mass, i.e. before it is foamed or made microporous, dyes are added or in which the microporous film dyed with acidic or mordant dyes and then the color is developed. These known methods have disadvantages. For example, dyeing by adding dyes or pigments to the polymer mass can only be carried out in batches and a multitude of hues cannot be easily achieved. Acid or stain dyeing is a

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multi-stage process that is only carried out at a higher temperature and cannot easily be used for coloring thick sheets or films.

These disadvantages are alleviated by the method according to the invention avoided, which is based on a simple dyeing technique that is easily used for dyeing foils or films made of microporous polyurethane can be used. It has been found that inks soluble in organic solvents Coloring microporous polyurethane at room temperature. According to the invention, any solvent-soluble Dyes are used, however, certain are in solvents Soluble dyes are preferred, namely the metal chelates of certain 2: 1 hydroxyazo dyes of the .general formula

N = NA- (SO ₂ OH ») _n '

• χ

wherein A is a phenolic, naphtholic or enolic coupling component which is coupled in the o-position or near the hydroxyl group, while X is a metallizable group in the o-position to the azo group; the dye does not contain any other ionizing group, η stands for 1 or 2 and the methyl sulfone group is directly bound to an aromatic nucleus. Metallized dyes of this type are _{marketed by J 0} R. Geigy & Company under the registered trade name "Irgacet" and their constitution is described in US Pat. No. 2,551,056. These dyes are preferred according to the invention since they penetrate the polyurethane better than other dyes which are soluble in solvents and also give more uniform colorations than these.

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It has been found that metallized dyes of the above type which have been used in an organic solvent which does not contain. solvent for polyurethanes is, dissolved or dissolved and dispersed, microporous polyurethanes in deep and uniform Color shades.

The process according to the invention for dyeing microporous polyurethane accordingly consists of the following stages:

(1) Impregnation of the polyurethane with a dye bath that contains 0.1 to 21 <$> of a soluble dye and an organic solvent for this dye which does not dissolve the polyurethane

(2) Separating the excess dye bath from the impregnated polyurethane and · ·

(3) drying the impregnated polyurethane.

Preferably the soluble dye is a metallized monoazo dye, especially one in which the Monoazo dye's general formula

N = NA- (SO ₂ - CH,) _n

in which A is a member of a group of coupling components consisting of phenolic, naphtholic and enolic Coupling components consists in liachbarstellunp; are coupled to the hydroxyl group, while X represents a metallisable group in ortho to the azo group and the dye has no other ionizing group; in the formula η means 1 or 2.

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In order to keep any undissolved dye particles in dispersion, a dispersant which is soluble in the organic solvent is preferably added to the dyebath. The microporous polyurethane film is soaked in the dye liquid by immersing it in the dye bath at room temperature for a few seconds or until it has absorbed about 50 ti of its weight in liquid. The film or sheet can be kneaded a little so that the

solution penetrates better. After "removal from the Färbefc bath, the film or sheet is dried at around 65 to 120 C, so that a uniformly colored material is obtained. No further processing is necessary.

In the examples below, methanol is used as the organic solvent, but other organic liquids can also be used according to the invention. Examples include ethyl alcohol, butyl alcohol, acetone, 'Me'thyläthyiketon, methyl isobutyl ketone, cyclohexanone, diacetone alcohol, methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, benzyl alcohol, light mineral oils, methyl and ethyl cellosolve, etc. The dye concentration in the dye can between 0.1 and 21 io vary, depending on the desired solubility and the Far.b'tiefe * friendliness of the dye in the solvent in question.

Microporous polyurethane on which the inventive Process in particular refers, generally speaking, to those substances that are leather-like in nature .and can therefore be used as a leather substitute. These leather substitutes and methods of making them are in various patents, e.g. in U.S. Patents 3,100,721, 3,169,885, 3,214, 290, 3, 284, 274, 3,336,183 and 3,369,925; in the Belgian patent specification 636 018, the French. Patent specification 1 514 955 and the French. Patent 145,693.

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The preferred polyurethanes are the elastomeric polyester urethanes, those made from a polyester terminated with hydroxyl groups, a diol and diisocyanate or from caprolactone, a MoI and diisocyanate are made.

The examples in which the parts are parts by weight illustrate the invention in more detail without restricting it.

example 1

40 g of a polyether urethane prepared from hydroxylpolytetramethylene oxide, diphenylmethane-p, ρ'-diisocyanate and 1,4-butanediol according to US Pat. No. 2,899,411, Example III, are dissolved in 160 g of p-dioxane. The solution is ^{heated to 95 0} O and kept at 90 to 95 ° C, while 57.1 g of an alkane hydrocarbon solvent with a boiling range of 177 - 198 ⁰ C, a KB value of "27 and an aniline cloud point of 84, 8 ⁰ C are added to what is happening within 12 min with continued stirring. the initially clear solution is then cooled and opeleszent at 42 ⁰ C. It further allows to 39 ° C to cool and then sweeps the mass obtained in a thickness of about 5 mm on the surface of a cotton fabric, each dm weighing 0.88 g. The coated web is dried for 16 hours at room temperature or about 1 1/2 hours at room temperature and then for 2 hours at 65 ° C. After drying, has the spread is a little more than 1 mm thick and has a very similar feel to that of leather; in terms of resistance to wear and tear and permeability to water vapor or "breathability", the product is of course equivalent to leather.

The fabric coated according to the invention allowed 1.9 g of water through within 24 hours. The M.V.T. value can be 1.9 g / 10 cm / 24 hours are given, compared to leather that `` has a M.V.T.-

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Value from 0> 5 "to 3.5 g / 10 cm / 24 h, depending on the type of leather.

The breathable microporous material was placed at room temperature for 8 to 9 seconds in a dye bath consisting of 94 parts of methanol, 5 parts of Igepal C0210 and 1 part of Irgacet-Schwarz-RL. The available under the registered trademark "Irgacet Black RL" pre-metallized monoazo dye is including its preparation are described in U.S. Patent 2 551 056. The microporous polyurethane film is kneaded in the dye bath so that it absorbs about 50 io of the polyurethane weight in liquid. The web is then at 66-121 ⁰ C dried to obtain a uniformly black-colored sheet of microporous polyurethane which is equivalent in appearance to a black-colored leather. The breathability and other desirable properties of the microporous material are not affected by the coloring.

Example 2

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Using another black dye (Color Index Solvent Black 26) instead of Irgacet-Black-RL resulted in similar results Results obtained, however, the penetration of the dye and the uniformity of the coloration not quite as good were as in example 1.

Example 3

According to US Pat. No. 2,871,218, column 4, lines 13 to 27 j, a polyester urethane with a molecular weight is used manufactured by about 60,000. A mixture of 1447 .g (1.704 Mol) hydroxylpolytetramethylene adipate, molecular weight 849? Hydroxyl number 130.4, acid number 0.89, and 109.6 g (1.218 mol) of 1,4-butanediol is melted in a 4 liter flask and with

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a Spiralbandrührer 20 min at a pressure of 5 "mm to 6 and 100 - stirred 110 ⁰ C. To the mixture, then 730 g (2 _f 92 mol) of diphenylmethane pjP' diisocyanate added The mixture is stirred for 1 min and the.. The mixture is then poured into a greased can with a volume of 3.4 l, which is immediately closed with a screw cap and then ^{kept in the oven for 3 1/2 hours at HO 0} C. After cooling, the product is converted into a 20 # solution of polyester urethane in p-dioxane produced.

56.5 g of n-butanol are added to 43.5 g of the solution at 75.degree slowly admitted. A cloudy mixture forms, which becomes clear when heated to 80 ° C. The one when it cools down again The solution that becomes cloudy is then about 2.5 mm thick

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brushed onto a cotton cloth (0.88 g / dm) and air-dried at room temperature for 16 h; The finished product has a leather-like feel, excellent wear and tear resistance and is equivalent to natural leather in terms of its permeability to water vapor and its breathability.

The above product passed 2.7 g of water through within 24 hours. The MVT value of the product may be 2.8 g / 10 cm ² / h are given 24, compared to leather that a MVT value of 0.5 to 3.5 "g / 1O
concerned leather.

from 0.5 to 3.5 g / 10 cm / 24 h, depending on the type of

The microporous polyurethane primed with cotton is then placed in a dyebath consisting of 93 parts of methanol, 5 parts of Igepal CO 210, -2 parts of Irgacet-Braun 2 GL. And kneaded up to a liquid absorption of about 50 μ-. After drying at about 99 ° C., a smooth, uniformly colored microporous web was obtained. Breathability and other desirable properties were virtually unaffected by the dyeing.

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Example 4

The procedure is as in Example 3, but with one

20 $ solution of the polyester urethane in tetrahydrofuran used will. 50 g of the solution are then kept at 30 C, while 50 g of n-butanol are added. The mixture is then heated, with stirring, to about 65 ° C, at which temperature it is represents an opalescent dispersion. The dispersion is then about 2.5 mm thick on a cotton cloth (0.88 mm / ·

dm) and air-dried at room temperature for 16 h. The product has a leather-like feel, excellent wear and abrasion resistance, and permeability for water vapor or a breathability equivalent to that of leather.

2.7 g of water vapor penetrated through the product prepared according to the invention within 24 hours. The MVT value of the product can be specified cm h 24 / 2.8 g / 10 compared to leather, * depending on their nature an MVT value of 0.5 to 3.5 g / 10 cm ^2/24 h has.

The synthetic leather was g-dyed according to Example 1, the The dye bath, however, contained 1 ^ Irgacet-Red-BL »The resulting, evenly colored product had essentially the same breathability as the uncolored material.

Example 5

150 g of a 20% solution of that used in Example 4

Polyester urethanes are produced and ^{heated to 9O 0} C,

3 *

while 10 cm of n-hexanol are added within 20 minutes. the Solution, initially remains clear, but is then cooled by 5 ° C until opalescence occurs and then further. the chilled solution; is then cut to a thickness of 4.7 mm

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Poured on glass plate and dried at room temperature for 40 h and then at 66 ^{° C. for 2 h.} The film is then peeled off. The dried film has a thickness of about 1.3 mm

and a leather-like handle, good resistance to

2 Wear and tear and leaves 3> 5 g per 10 cm within 24 hours Water vapor through. Its resistance to permanent deformation through creasing or bending and its tensile strength are better than some types of leather, but not as good as the products from example 1 to 4 »

The 1.3 mm thick film made of microporous polyurethane was colored according to Example 1 with Irgacet Black RL and resulted in a evenly colored black product, which in terms of its breathability and other desirable properties corresponded to the uncolored material.

Example 6

Similar results as above were obtained when the in Example 5 used dye was replaced by index solvent black, but with the penetration of the dye and the uniformity of coloration was not as good * as when used from Irgacet dye.

Example 7

A sheet of white microporous polyurethane on top of fibrous backing (commercially available under the name "Corfam")> which is suitable for the production of shoe uppers was dyed black according to Example 1 and resulted in a Uniformly colored product with essentially the same properties as in the uncolored state.

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Example 8

30 g of a polyester-based polyurethane (obtained from 1000 parts of a linear polyester, e.g. ethylene glycol adipate, with a molecular weight of 2000, a hydroxyl number of about 50 and an acid number of 1; 90 g of 4-butylene glycol and 400 g of 4,4 ^I -diphenylmethane diisocyanate according to German Patent 1,189,268) are dissolved in 70 g of N, N ¹ -dimethylformamide. 53 g of sodium chloride, ground to an average particle size of 13 / U, are then dispersed in the solution and the whole thing is spread with a doctor blade on a temporary base made of porous, sintered polyethylene of high density and low permeability (1.6 mm thick ) consists. The spread with the backing is placed with the coated side down in water at 40 ° C. in order to coagulate the polymer. The spread is soaked in water until essentially all of the dimethylformamide and salt are removed. Then it is dried and stripped from the base.

The microporous film prepared as above has a

Thickness of about 1.8 mm and was made with Irgacet-Sehwarz RL according to Example 1 colored black; a uniformly colored one was obtained Product whose breathability, tensile strength and modulus hardly change compared to the uncolored state would have.

Example 9 '

The same results were obtained when the example 8 used Irgaeet-Schwarz RL was replaced by another black dye (Color Index Solvent Black 7), but not the penetration and uniformity of the color were just as good as in example 8. '

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All of the dyes mentioned in the examples were insoluble in water and therefore resistant to the tendency to leach out of the material when it is used for uppers of shoes or other objects which come into contact with moisture during use.

Claims

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Claims (2)

Claims 1. A method for dyeing microporous polyurethane, wherein the polyurethane is impregnated with a dye liquid which 0.1 to 21 wt .- $ dye in a liquid vehicle for the dye but not a solvent for the polyurethane contains, squeezes off the excess dye bath and dries the polyurethane soaked with dye liquid, characterized in that one is used as the dye a soluble metalized monoazo dye and as a bath liquid a solvent is used for this dye. 2. The method according to claim 1, characterized in that there is a metallized monoazo dye used, in which the konoazo component is the general formula N = NA- (SO ₂ where η = 1 or 2 and A is a member from a group of phenolic, naphtholic and enolic coupling components and is coupled adjacent to the hydroxyl group, while X is a metallizable group adjacent to the Represents azo group and the dye does not have any other ionizing group. 0 098 14/1772