CS242276B1 - Polypropylene mixture suitable for surface-dyeing fibres and foils production - Google Patents

Description

(54) Polypropylene blend suitable for the manufacture of super-dyeable fibers and films

The present invention relates to a polypropylene composition which contains basic modifiers and is suitable for the production of surface-colorable fibers and films.

Polypropylene fibers and films have advantageous physical and mechanical properties for wider applications. However, a certain limiting factor for the further spread of hydrophobic polypropylene fibers in the textile industry is their difficult dyeability by conventional methods.

Various methods have been proposed to improve the colorability of polypropylene, which have mostly used the possibility of physically modifying polypropylene with low molecular weight and polymeric substances.

When using polymer-type modifiers, difficulties often arise due to their poor compatibility with polypropylene, poor processability in the spinning process and reduced fiber strength.

Improvement of the compatibility of the components in the polypropylene composites can be achieved, according to some proposed methods, by using macromolecular modifiers based on basic nitrogen-containing copolymers in the backbone or in the side groups of the macromolecule, wherein these modifying agents bind the intermolecular interaction forces of the acid dye molecule. 22,523 (1967); 30,028 (1969); 17,242 (1981); U.S. Patent No. 192,298).

In order to achieve effective dyeing, some of the proposed processes require a higher concentration of modifier in the polypropylene, also in the presence of transfer agents, resulting in a reduction in the mechanical properties of the fibers.

The present invention provides an advantageous process for modifying polypropylene for applications to shaped articles. The invention relates to a polypropylene blend suitable for the production of surface-dyeable fibers and films, characterized in that it consists of 85 to 99% by weight of isotactic polypropylene and 1 to 15% by weight of a random copolymer comprising repeating units of formula A. with

OCOlCHJ N ^ * \ _n second

(A) wherein R ¹ and R ² denote the same or different alkyl groups having 1 to 4 carbon atoms, n is 1 to 11, x is 1 to 3, ethylene (B) and vinyl acetate (C) repeating units

-CřVCH _z - - -CH-CH 3> ~ [ ^A (A) in ococh ₃

where y is from 6 to 30 and z is from 1 to 4 obtainable by polymer-analogous transformation of 100 parts by weight of an ethylene-vinyl acetate copolymer, 5 to 300 parts by weight of an alkyl ester of a Ν, dial-dialkylsubstituted amino acid of formula

R ¹ O '

N- (CHzjn -C

FROM \

R ² OR ³ wherein R ¹ , R ² , n have the same meaning as in unit A and R ³ denotes a methyl or ethyl group, in a solution of aromatic solvents in the presence of basic catalysts such as alkali metal amides.

The polymer-analogue reaction product is preferably isolated from the solution by precipitation into ethanol and, after separation and drying, homogenized with polypropylene and melt granulated on an extruder.

Preferably, a product with an average molecular weight (Mn) in the range of 10,000 to 00,000 is used for the modification of the polypropylene, the polymerization step of which is analogous to that of the starting ethylene-vinyl acetate product.

The copolymers of the present invention are prepared by polymer-analogous transformation of an ethylene-vinyl acetate copolymer by the action of compounds such as e.g. methyl or ethyl ester of N-methylalanine, ethyl ester of N, N-diethylglycine, methyl or ethyl ester of N, N-diethyl-β-aminopropionic acid, ethyl ester of N-methyl-N-ethyl-β-aminopropionic acid, methyl or ethyl ester of N, N- dibutyl-β-aminopropionic acid, ethyl N-methyl-N-butyl-β-aminopropionic acid, methyl or ethyl N, N-dimethyl-s-aminocaproic acid, methyl or ethyl ester of N, N-diethyl-β-amino-caproic acid, methyl or ethyl N, N-dimethyl-.beta.-aminocaprylic acid or pelargonic acid, methyl or ethyl .beta., .beta.-dimethyl (or diethyl) .beta.-aminoundecanoic or lauric acid.

The polymer-analogue transformation process of the ethylene-vinyl acetate copolymer is carried out in a temperature range of 70-135 ° C, in a solution of dried xylene or toluene, in an inert atmosphere of dried nitrogen or argon, with the addition of powdered alkali metal amides of which lithium amide has high catalytic efficiency.

Upon completion of the polymer analog reaction in the conversion range of 60 to 80%, it is preferred to use an ethanol solution containing 7 to 15% water to precipitate the modified copolymer to deactivate the catalyst and extract the alkali metal hydroxides.

The product precipitation solution is preferably recovered by rectifying the filtrate after separation of the product, and unreacted N, N-dialkylamino acid ester is isolated from the distillation residue.

For the preparation of the fibers, it is preferred that the polypropylene mixture containing the modified copolymer in amounts of 1 to 15% by weight is homogenized with stabilizers and / or stabilizers. with the addition of calcium or sodium stearate and the granulated mixture is then melt-spun in an inert atmosphere.

The dyeing of the fibers is carried out at 100 ° C by conventional methods in aqueous solutions containing anionic dyes, electrolyte, at a pH preferably in the range of 2.5 to 4, at a weight ratio of the dyeed product to the dyeing solution in the range of 1:20 to 1:50.

When using acid dyes, it is advantageous to carry out the dyeing with the addition of surfactants, in particular when dyeing the mixture of modified fibers with polyamide fibers.

To adjust the pH of the bath, especially when the bath contains electrolytes such as salts of aliphatic or aromatic acids, it is preferred to use formic acid, acetic acid, benzenesulfonic acid, or inorganic acids such as sulfuric acid and phosphoric acid.

The following examples are given to illustrate the invention:

Example 1

150 g of granulated ethylene-vinyl acetate copolymer (EVA) (vacuum dried in the range of 0.07 to 0.2 kPa) at 50 ° C for 8 hours and after addition of 1,400 ml of distilled xylene (sodium-dried) are charged to the reactor. under reflux, the EVA copolymer containing 22% by weight of vinyl acetate is dissolved at 100 ° C with a slight flow of dried nitrogen.

6.7 g of lithium amide suspended in powder form in 100 ml of dried xylene are then added to the solution, and 90 ml of N, N-dimethyl-s-amino-caproic acid ethyl ester are added dropwise over a period of 45 minutes. P2O5 is used to dry the ester before vacuum distillation.

The temperature is raised to 125 degrees C over 15 minutes, 20 ml of N, N-dimethyl-.beta.-aminocaproic acid ethyl ester is added after 40 minutes and the re-esterification is continued under stirring for 110 minutes under a flow of dried nitrogen, ranging from 125 to 130. C.

After completion of the reaction, the solution, cooled to 80 ° C, was gradually added with stirring to 5,000 ml of a 90% aqueous ethanol solution. The copolymer is separated by filtration through a fabric, extracted again with an aqueous ethanol solution for 10 h. After isolation, the yellowish product is dried under vacuum at 0.1 to 0.2 kPa at 40 ° C (Mn = 36,000).

A dried copolymer containing 2.2 wt. nitrogen, is added in an amount of 140 g to

840 g of powdered polypropylene Tatren HPF and after addition of 20 g of sodium stearate, g of tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) hutane and 3 g of 2-hydroxy-4-octyloxybenzophenone, the mixture is granulated and spun 260 [deg.] C.

The knitted fibers in a ratio of 1: 3.7 are made for coloristic evaluation. The staining is carried out in a water bath containing 2% acid dye, e.g. Midlon Red PRS or Suminol Fast Blue PR, 2% polyethylene oxide / alkylphenol based surfactant, 4% sodium salicylate or sodium sulfate, at pH 3, adjusted with formic acid.

The modified fabric dyeing bath is first heated from 50 ° C to 100 ° C for a period of 40 min and dyeing is performed at 100 ° C for 60 min. Under these conditions, bath ¹ is pumped to 99-99.8% and after washing at 60 ° C for 15 min in a 0.5% sodium dodecyl sulfate solution, the amount of fixed dye in the fabric is in the range of 92-96%.

Example 2

10 g of granulated ethylene-vinyl acetate copolymer containing 34 wt. vinyl acetate (vacuum dried 0.1 kPa at 50 ° C for 8 h, Mn = 22,000), 110 ml of xylene (sodium boiling) and after dissolution of the copolymer at 125 ° C, dry argon flow was added 0.35 g of lithium amide and 0.2 g of sodium amide.

With vigorous stirring, 12 ml of N, N-dimethyl-11-aminoundecanoic acid methyl ester is added after 30 minutes and after 8 minutes 8 ml of ethyl N, N-diethyl-η-amino amino acid is added.

The temperature of the reaction mixture is maintained at 125-130 ° C for 120 min, then the solution is cooled and the modified copolymer is isolated by precipitation in an ethanol solution containing 10% by volume. water. The dried product (at a vacuum of 0.1 to 0.2 kPa at 45 ° C, containing 2.6% nitrogen by weight) is mixed in an amount of 1.65 g with 28.05 g of powdered polypropylene Tatren HPF, 0.3 g of stearate. sodium and 0.03 g of tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) buffet and 0.015 g of 2,6-di-tert-butyl-4-methylphenol.

The mixture was homogenized at 220 ° C under an inert atmosphere. Films with a thickness of 0.1 mm are prepared from the modified polypropylene by compression at 210 [deg.] C., which are used for coloristic tests according to the procedure of Example 1.

For stained deep foil shades of Midlon Blue E, at a bath yield of 99.8%, 7.6% dye is extracted while shampooing with a 0.5% sodium lauryl sulfate solution at 60 ° C for 15 minutes.

Example 3

150 g of ethylene-vinyl acetate copolymer containing 23 wt. The vinyl acetate was dissolved in 1400 xylene. (Drying procedures of the raw materials are given in Example 1.j) To the solution, 6.9 g of lithium amide are added at 125 ° C, and after 45 min, 140 ml of N, N-diethyl- / 3- ethyl ester are added successively with stirring under inert gas flow and stirring. of aminopropionic acid and after 30 min 20 ml of N, N-dibutyl- [3-aminopropionic acid methyl ester.

The further procedure for synthesis, product isolation, fiber preparation and color evaluation is the same as in Example 1. Using Midlon Blue E dye, the bath is depleted to 99.6% under the specified conditions and in the fabric after shampooing at 60 ° C for 15 min at 0 A 5% sodium dodecylsulfonate solution is fixed with 91% dye.

Example 4 g of ethylene-vinyl acetate copolymer with a content of 27% by weight. The vinyl acetate is dissolved in 100 ml of dried xylene at 125 ^DEG C., 0.48 g of lithium amide is added under the conditions of Example 1 and 2, and after 45 minutes under an inert atmosphere with vigorous stirring, 12 ml of N-ethyl ester, N are added. -butyl-β-aminopropionic acid and 5 ml of N, N-diethylglycine methyl ester.

The procedure is as in Example 2. When the films are dyed in a bath containing Dyeing Red PRS at a concentration of 2%, based on the weight of the films, the bath is depleted to 97%. After washing at 60 ° C for 15 min in a 0.5% sodium dodecylsulfonate solution, 88 percent of the fixed dye remains in the films.

The invention can find widespread use in the chemistry and processing of polymers for the manufacture of surface-colorable molded polypropylene articles.

Claims (1)

SUBJECT We claim: Polypropylene blend suitable for the manufacture of surface-dyeable fibers and films, characterized in that it consists of 85 to 99 percent by weight of isotactic polypropylene and 1 to 15% by weight of a random copolymer containing repeating units of formula A wherein y is 6 to 30 and z is 1 to 4 obtainable by polymer-analogue transformation of 100 parts by weight of a copolymer of ethylene with vinyl acetate, 5 to 300 parts by weight of alkyl esters of a Ν, dial-dialkylsubstituted amino acid of the general formula R ¹ O \ Z N - (CH 2) _n -C where R ¹ and R ² denote the same or different alkyl groups having a carbon number of 1 to 4, n being 1 to 11, x being 1 to 3, repeating units of ethylene (B) and vinyl acetate ( C) R ² OR ³ wherein R ¹ , R ² , n have the same meaning as in unit A and R ³ denotes a methyl or ethyl group, in a solution of aromatic solvents in the presence of basic catalysts such as alkali metal amides. -CHfCHi -CH-CHn-