DE4221917C2 - Use of antistatic additives for coating compositions for textile fabrics - Google Patents

Description

The invention relates to the use of antistatic additives Coating compounds for textile fabrics that make connections the groups of aminopolycarboxylic acids, aminopolyphosphonic acids or / and contain the alkylphosphonic acids.

The electrostatic charging of textile floor coverings is a Problem with carpet manufacturers and users in offices, restaurants, Hotels, computer rooms and in the living area are constantly confronted. In the winter months when the relative humidity in the centrally heated rooms is very low, d. H. often only at 20-30% malfunctions from electrostatic charging are more common than in the seasons when the relative humidity in the Clearing is higher. This affects not only textile floor coverings, but also other home and utility textiles.

To prevent or reduce electrostatic charge various paths have been taken or suggested, such as: Spraying on antistatic agents; Use of modified, conductive Fibers, carbon-coated fibers, steel fibers or metallized threads; Apply a conductive back coating or a conductive back consolidation primer. The usage antistatic or conductive pile fibers clearly leads to one Reduction of electrostatic charge, but still remains an additional conductive back coating is recommended, especially so  the annoyance caused by unpleasant electrical shock sensations to rule out with certainty. Especially when it comes to cut pile goods by cutting and shearing the pile the course of the yarn at each Loop is interrupted, is a conductive back coating still required.

From DE-AS 12 17 916 and 12 86 669 it is known to be carbon black Antistatic in natural and synthetic latices for carpet coatings to use. Because of the black inherent color of the soot Usability but set narrow limits. In U.S. Patent 3,658,744 the use of alkali or alkaline earth salts from low molecular organic acids such as B. Potassium formate as antistatic effective component in back coatings of textile surfaces formed described. Products on this basis are outstanding excellent antistatic effects have the disadvantage, however Under certain circumstances to cause water stains or soiling. Underneath is to be understood that phenomenon that when getting wet locally after the Drying or later use stains or clear spots become visible with increased soiling. To make antistatic of textile fabrics were also in DE-AS 28 24 614 and 25 29 939 polyaminopropionic acids or salts of polymer acids with amines wrote, but these substances behave with regard to water stains even worse.

It was therefore the task of antistatic treatment of textile fabrics to find the excellent antistatic effect with insensitivity to the formation of water stains or soiling on dried damp areas or water combine stained spots.

It has now been found that the undesirable formation of water stains and the resulting increased tendency to soiling is restricted if in coating compositions for textile fabrics as an antistatic additive complex-forming compounds  from the groups of the aminopolycarboxylic acids, the aminopoly phosphonic acids and / or the alkylphosphonic acids or their salts be used.

To the group of complexing aminopolycarboxylic acids include aminopolycarboxylic acids and / or their salts, that of the general formula

correspond in which mean:
R ₁ , R₂ and R _{3 are} the groups -CH ₂ COOH or -CH ₂ COO⊖, which can be the same or different,
R _{4 represents} the groups -CH ₂ COOH, -CH ₂ 2COO⊖ or -CH ₂ CH ₂ OH,
n = 2 or 3 and p = integers from 0 to 2.

Examples of such compounds are ethylenediaminetetraacetic acid (EDTA), Diethylenetriaminepentaacetic acid (DTPA), hydroxyethylethylenediamine triacetic acid (HEDTA), nitrilotriacetic acid.

To the group of complexing aminopolyphosphonic acids include aminopolyphosphonic acids and / or their salts of the general formula

in which mean:
R ₅ , R ₆ and R _{7 are} the groups -CH ₂ PO ₃ H₂; -CH ₂ PO ₃ H⊖ or -CH ₂ PO ₃ ² ⊖,
R ₈ as R ₅ , R ₆ , R ₇ , hydroxyalkyl or hydroxyalkylaryl,
m = 2 or 3 and q = integers from 0 to 5.

Examples of suitable aminopolyphosphonic acids are Amino-tris (methanephosphonic acid) (ATMP), Ethylenediamine tetrakis (methanephosphonic acid) (EDTMP), Diethylenetriamine pentakis (methanephosphonic acid) (DTPMP).  

Belong to the group of complexing alkylphosphonic acids 1-hydroxyethane-1,1-diphosphonic acid and 2-phosphonobutane-1,2,4- tricarboxylic acid (PBTC).

As salts of aminopolycarboxylic acids, polyphosphonic acids and Alkylphosphonic acids are preferably the alkali metal salts, however, others such as e.g. B. alkaline earth metal, suitable.

The amount of additives to be used according to the invention is in the range of approx. 1.0 to approx. 50 g quantity per square meter.

Furthermore, the coating composition consists of known and usual components such as latex, film formers, fillers and the Processability-improving substances such as thickeners, Setting agents, preservatives and solvents and / or Water together. Known other antistatic components can also contain in addition to the components of the invention be, provided that their amount to be achieved according to the invention Effect not affected or reduced.

Production of the antistatic additive Example 1

33.3 g of formic acid (85%) and 11.7 g of nitrilotriacetic acid are in Dissolved 60 g of deionized water and with 91.6 g of potassium hydroxide solution (45%) pH 8.1 adjusted. This gives a solution of approximately 34.5% content, of which approx. 26% potassium formate and approx. 8.5% dipotassium salt are nitrilotri are acetic acid.  

Example 2

19.7 g formic acid (85%) and 23.2 g nitrilotriacetic acid are dissolved in 60 g of deionized water and approx. 78 g Potassium hydroxide solution (45%) adjusted to pH 8.1. A solution results of approximately 35.2%, which is approximately half potassium formate and dipotassium salt which contains nitrilotriacetic acid.

Example 3

50 g of an aqueous amino-tris (methanephosphonic acid) solution (50%) are mixed with approx. 49 g of potassium hydroxide solution (45%) adjusted to pH 8.1 and then with 103.4 g of potassium formate solution (63%) stirred. The solution obtained contains 51.9% substance, half of which are potassium formate and potassium salts of the phosphonic acid.

Example 4

3.0 g of an aqueous solution are added to 30.0 g of deionized water (50%) of 2-phosphonobutane-1,2,4-tricarboxylic acid and with approx. 28 g potassium hydroxide solution (45%) adjusted to pH 8.1. Then be 15.9 g of a potassium formate solution (63% in water) and finally 10.0 g Sodium tripolyphosphate (powder) added. An end product is obtained of about 39% content, which is about 16% sodium tripolyphosphate, approx. 16% potassium formate and approx. 7% potassium salt of the 2-phosphonobutane 1,2,4-tricarboxylic acid distributed.  

Examples of use Example 5

The carpet primer compound used to test the antistatic additives according to Examples 1 to 4 had the following composition:
100 parts by weight of polymer latex with 50% solids, based on 35% butadiene and 65% styrene, in water or solvent
250 parts by weight of chalk
a parts by weight of the additives obtained according to Examples 1 to 4,
24 parts by weight of water and any other components.

The plain-colored tufted velor carpet was 100% of this Compounds coated. The quantities "a" of the antistatic additive effective according to the invention according to example 1 to 4 chosen so that after the application of the compound pro 13.5 g of the additive on the carpet were found.

Example 6

14 parts by weight of an aqueous polyacrylate solution (25%) are added to 100 parts by weight of the additive obtained according to Example 2. Based on the active substance, the amount of polyacrylate (dry substance) used is 10%. The corresponding coating then contains 13.5 g / m ^{2 of} active substance of the additive obtained according to Example 2 and 0.135 g / m of active substance of the polyacrylate.

That according to Example 5 with the antistatic additives Carpets equipped according to Examples 1 to 4 are 20 minutes dried at 130 ° C and to test their antistatic behavior according to DIN 54 345 (parts 3 to 6) at least 7 days in a dry climate of 25% relative humidity and 23 ° C air-conditioned. After that the antistatic test was carried out by measuring the surface resistance the back (in ohms) and the electrostatic charge in the walk test with the Estameter device (in kilovolts).  

To determine the sensitivity to water stains, the from Technical standards committee material testing FNMC9c21 recommended method applied (cf. chemical fibers / textile industry 1977, pages 828-829). For this purpose, carpet sections were coated in the manner indicated at least 50 × 50 cm in size at 65% relative humidity and air-conditioned at 20 ° C for 48 hours. Then 50 ml were desalted Water was applied and the test specimens were allowed to dry 65% / 20 ° C designed for 72 hours. After that was done in the usual way in a drum machine with a mixture of vacuum cleaner and model dirty and the intensity of the soiling after a five-level grading visually assessed. Here means Grade 1 that water spots are not recognizable and Grade 5 that it is very pronounced; the intermediate grades stand for indistinct, clear and strong water stains.

The test and rating values found for the respective additive application quantity "a" (equal to 13.5 g / m ² ) for surface resistance (in ohms). Estameter charging (in kilovolts) and soiling behavior (grades 1 to 5) are for examples 1 to 4 according to the invention, and also for a comparison example with a known antistatic agent with a strong tendency to water stains ("a" with potassium formate according to US Pat. No. 36 58 744) and a table for a test specimen without antistatic component "a".

Test results for Examples 1 to 7

The compilation shows that the Estameter charge decreases by an order of magnitude to about 1/10 compared to a coating without antistatic, with the same application quantity; likewise, the surface resistance decreases by about 5 orders of magnitude from 10 ¹² to about 10 ⁷ . With a known reference substance, the soiling behavior is a poor grade of 4.6 and improves to values in the range from 1.6 to 2.6 by using the antistatic new additives. The comparison of Examples 1 and 2 shows that an increase in the content of the nitrilotriacetic acid according to the invention compared to the content of known antistatic agent (potassium formate) has a significant reduction in the tendency to soiling.

Example 7

The combinations explained in Examples 1 to 6 Formats with complex-forming compounds are described in Example 7 (Table 2) in comparative experiments of the known combination Potassium formate polyol / polyglycol (the US-PS 3658744) contrasted, to the additional effect of inhibiting migration and reduced Water stains and soiling tendency when using the complex to show forming connections.

The application of the primer, which contains the active agent or its combination with potassium formate and agents 1-7 of the prior art, was carried out with a latex
500 parts of butadiene-styrene polymer (50% solids)
180 parts of water
1250 pieces of chalk.

Of these, 700 parts each with 12.5 parts of each Additive or its combination with potassium formate and with 12.5 parts of water are added and applied to 1 m² of carpet material (Middle edition in g / m²). The pollution of the water stains was with Grades from 1 (no soiling) to 5 (very heavy soiling) on 3 test objects by 2 test persons independently of one another visually assessed and is given as the mean of these 6 tests. In the combined uses with potassium formate (KF) is weight ratio 1: 1 each.

Potassium formate alone shows low charge and low Resistance is known to have good antistatic properties, however Water stain and soiling sensitivity with 4.7 very bad. Glycerin and polyethylene glycol 600 (alone and combined with KF in higher and lower quantities) already show somewhat higher charges values (0.20-0.32 kV) with resistance values, which can be combined with KF of 8.10⁸ or 1.10⁹ decrease by about two powers of ten; the higher KF content also acts as a lower resistance out. However, these known good antistatic values have the disadvantage that that their water stain contamination values with the grades 4-5 much too are high and are therefore not acceptable.  

In Examples Nos. 8-15 of Table 2, uses of complex-forming agents each individually and in a combination nation with potassium formate (1: 1). These funds show significant to substantial reduction in water stains, up to the excellent values of 1.3. The values for the Charging as well as for derivation remain in the area more well known Agent with an antistatic property but poor soiling property. If you combine the new, low-migration funds with a small amount of a known antistatic agent such as B. potassium formate, so you get another essential Improvement of the derivation (reduction of the resistance by 3 to 1 Powers of ten) with approximately constant soiling. The Connections according to the application thus result in the alone desired improvement of the soiling behavior in the case of more common Charging and in combination with potassium formate an additional one Improve the antistatic properties.  

Table 2

Assessment of re-pollution

Claims (6)

1. Use of complex-forming compounds from the groups of Aminopolycarboxylic acids, aminopolyphosphonic acids or / and the alkylphosphonic acids or their salts as antistatic effective additive in coating compositions for textile Flat structures with reduced dirtiness.   2. Use of compounds according to claim 1, characterized in that an aminopolycarboxylic acid of the general formula wherein R ₁ , R ₂ , R _{3 are} the groups -CH ₂ COOH or -CH ₂ COO⊖, identical or different,
R ₄ the groups -CH ₂ COOH, -CH ₂ COO⊖ or -CH ₂ CH ₂ OH
n 2 or 3
p integers from 0 to 2
mean, or / and a salt thereof is used. 3. Use of compounds according to claim 1, characterized in that an aminopolyphosphonic acid compound of the general formula wherein R ₅ , R ₆ , R ₇ , -CH ₂ PO ₃ H ₂ , -CH ₂ PO ₃ H⊖ or -CH ₂ PO ₃ ² ⊖
R ₈ R ₅ , R ₆ , R ₇ , hydroxylalkyl or hydroxyalkylaryl
m 2 or 3
q integers from 0 to 5
mean, or / and a salt thereof is used. 4. Use of compounds according to claim 1, characterized in that that 1-hydroxyethane-1,1-diphosphonic acid or / and a salt thereof is used.   5. Use of compounds according to claim 1, characterized in that 2-phosphonobutane-1,2,4-tricarboxylic acid and / or a salt the same is used. 6. Use of complex-forming compounds according to the claims 1 to 5 in combination with alkali or alkaline earth salts molecular organic acids as antistatic Additive in coating compositions for textile fabrics with reduced dirtiness.