DD129924B1 - METHOD FOR IMPREGNATING NEEDLE FELT - Google Patents

Description

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Title of the invention

Process for the preparation of a impregnating agent for needle felt

Field of application of the invention

The invention relates to a process for the preparation of a needle felt impregnating agent, preferably of synthetic fibers, which is used for example for the production of textile fabrics belonging to the class of so-called "lion-wovens" floor coverings. These needle felt carpets are more economical to produce than traditional woven fabrics. Would,

Characteristic of the known technical solutions

It is known to use carboxylated butadiene copolymer latexes as impregnating agents for the impregnation of needle felt by the method of full-bath impregnation or by application to the back of the needle felt (fluffing) (ТЬЗС 27 (1), 48-53 (1 ° 68)). In the full bath impregnation of the needle felt runs through the diluted binder in a padding, is then squeezed off and dried at temperatures between 110 and 150 ⁰ C, the height of the drying temperature of the type of fiber used in the felt is determined · The solidification of the back of the needle felt by Anflatsehen of the binder is somewhat uneconomical because

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more binder is required for the same Fasertnenge, as in the Vollbadimpprägniez'ung. It is advantageous here, however, that the surface of the felt remains free of binder and thereby retains its textile character. Maintaining a uniform depth of penetration of the binder into the felt is difficult because, inter alia, the prerequisite for this - a uniform needling of the fleece is often not guaranteed.

However, although carboxylated butadiene copolymer latexes are well-suited for their better adhesion to the fiber than other latexes or dispersions for impregnating needled felt, they have the particular drawback that they require drying temperatures in excess of 120 ° C. This is when using synthetic fibers in fleece, such as. As polypropylene fibers with a relatively low melting point, problematic and causes that at lower temperatures, the drying times must be extended. The economics of these methods for needle felt impregnation is therefore reduced. In the Ub-PS 3 215 647 the preparation of a latex Schauraes is described from a copolymer having reactive carboxyl groups together with a coreactive substance containing at least two reactive groups in the molecule »After drying, a product is obtained which is particularly suitable for foam coating; However, such compounds must also be dried at least at 120 ^° C. and can only be used if coagulation takes place before drying by increasing the temperature.

Object of the invention

The aim of the invention is, in the impregnation of needle felt, in particular of polypropylene fibers, with carboxylated Diencopolymerlatices to achieve sufficient adhesion of the binder on the fiber and thereby the drying of the web at low temperatures

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without prolonging the drying time. The dimensional stability of the impregnated needle felt is to be ensured or even improved,

Explanation of the essence of the invention

The invention is based on the object of developing a process for the preparation of an impregnating agent for polyamide _/ in particular of polypropylene fibers, based on carboxylated diene copolymer latices, which satisfies the above requirements.

The Aulgabe is inventively achieved in that for Nadelfilzimprägnierung a mixture of Diencopolyuierlatex is used with 1 to 5 T * carboxyl-containing monomers and an aqueous solution or dispersion of a reacting with the carboxyl group substance «The reactive substance during the preparation of the copolymer at a monomer conversion between 85 and 92 <f> , after which the polymerization is continued to almost 100 % Unjsatz. The amount of the reactive substance is 1 to I5 $> _t preferably 3 to 8% of the f Uesamtfeststoffgehaltes and is dependent on the amount of carboxyl groups in the latex. An excessively large amount of coreactive substance leads to a deterioration of the results until complete failure of felt consolidation.

According to the invention suitable coreactive substances are melamine, urea, phenolic, epoxy resins, ethylenediamine, dicyandiamides, polymer latices with functional groups, such as. B. Diaminäthylmethacrylatcopolymere.

The Diencopolymerlatex is in addition to the diene 1 to 5 Ъ unsaturated carboxylic acid at least 50 $> preferably 50 to 65 56, a vinyl aromatic compound such as styrene, wherein a portion of the styrenes can be replaced by acrylonitrile or other aliphatic monomers.

The carboxylic acids in the copolymer can mono- or polycarboxylic acids, individually or in a mixture, preferably with 2 to

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10 carbon atoms to be a molecule. Preferred monocarboxylic acids are, for example: acrylic acid, methacrylic acid, crotonic acid. As polycarboxylic acids кошшеп example Maieinsäure, Puraarsäure, itaconic acid in question. Substituted mono- or polycarboxylic acids are also suitable. The conjugated diene preferably contains 4 to 10 carbon atoms. Examples are butadiene, isoprene, 2,3-di ^m ethylbutadiene, but is preferably butadiene, to achieve special properties can also be substituted dienes such as ζ. As chlorine or Cyanbutadien be used. Although styrene is preferred as the vinyl aromatic compound in the copolymer, aliphatic monomers, such as. As acrylonitrile, methacrylonitrile, esters of unsaturated mono- or polycarboxylic acids with alcohols of chain length 1 to 10 carbon atoms, such as methyl acrylate, Athylaorylat, 2-ethylhexylacrylat be used. Substitution products such as hydroxyl or halogen compounds can also be used «

The emulsifiers used are sodium or potassium salts of alkylarylsulfonic acids having up to 20 carbon atoms. However, all known anionogenic and non-ionic polyraerization initiators can be used. Other polymerization auxiliaries, such as initiators, regulators and electrolytes, can be used in the emulsion polymerization in a known manner.

To achieve optimum properties when using the binder mixture according to the invention for impregnating needle felt, it is necessary, after addition of the coreactive substance to Diencopolymerlatex, the polymerization as far as complete conversion of the monomers, but at least up to a conversion of 98 / continue. In this case, a virtually complete pre-crosslinking of the polymer is achieved while maintaining the chemical and mechanical stability of the dispersion. The novel binder mixture of diene copolymer latex and coreactive substance gives an excellent impregnating agent for

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Needle felt made of synthetic fibers. In particular, it shows very good adhesion properties on polypropylene fibers whose impregnation as needle felt heretofore, also because of their low melting point, was problematic. It is surprising to the person skilled in the art that, in contrast to the known prior art, for example to the binder mixture according to US Pat. No. 3,215,647, the reactive substance added to the diene copolymer latex according to the invention does not cause coagulation before the end of the copolymerization, yet the strength of the needle felt with very good adhesion ensured on synthetic fibers and excellent dimensional stability and Florerholung of the finished product. Subsequent additional crosslinking at elevated temperatures is unnecessary.

Since with the latexes according to the invention optimum hardening of the needle felting is made possible already after the evaporation of the water, the user can optimally adjust the drying temperature of his processing plant taking into account the melting point of the fibers and thereby achieve a very high throughput speed of the needle felting material by his investment, resulting in a relative Energy savings equals. Regardless of the chosen curing temperature, the highest possible strength is always achieved.

Ausführunffsbeispiele

The properties of the butadiene copolymer latexes prepared according to the following examples, as well as the impregnated needled felts, are summarized in Table 1. These properties were determined as follows:

1І storage stability of the latex

A .probe of 100 ml is kept in a closed vessel at 60 ⁰ C and checked daily by viscosity measurements. At a viscosity increase of more

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$ 10 will end the exam. A test period of 6 days corresponds to a storage stability of more than 6 months under normal conditions.

Strength of latex filia

About 50 g of latex are thickened with a conventional thickening agent (eg, carboxymethylcellulose or sodium polyacrylate) and drawn out to a film on a glass plate using a 0.5- ^ш- VASAG ruler. This film is about 24 h at room temperature, dried, and then peeled from the glass plate and then at least 24 h at 22 ⁰ C £ 2 and stored 65 + I5% relative humidity.

From this film test pieces (standard rod 4 to TGL 1436О) are punched out with the following dimensions:

overall length 50 ШШ Width of the heads 8.5 mm land length 15 mm web width 4 mm

These test specimens are clamped in a tensile machine for low levels of strength (preferably up to 5 N maximum load) and stretched to break at a speed of 220 mm / min. The maximum strength value is read and converted to the area of 1 cm ^Ä .

3. Florian recovery

Flor recovery is determined according to TGL / 16-665 123/01 with a loading level of 20 N and a loading time of 2 h.

Dimension of the test piece: 10 cm χ 10 cm Testing and recovery takes place at room temperature.

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After 2 h and 20 h recovery, the thickness of the test piece is measured with a thickness gauge (adjusted to 50 mN / cm ² ) «

Thickness of specimen after recovery

^{Initial thickness of} the specimen ^{X 10} ° ~ * ^1огѳг -

HOLUNG

~. dimensional stability

For this purpose, the permanent elongation of impregnated needle felt samples is measured.

5 cm wide strips of 10 cm free clamping length are loaded in dry and wet condition in the needle direction with 5, 10 and 15 kg. Elongation is measured immediately after loading and after 1 h «

5, drying rate

The impregnated needle felt was dried for 25 minutes at 120 ⁰ C in a hot air oven "On the thus-dried material is performed Tetrapod test according TGL 16665128th

The needle felt of Example 5 was subsequently subjected to a crosslinking reaction of 15 minutes at I30 ⁰ C and the Tetrapod test on this material repeatedly "

example 1

In a stainless steel polymerization kettle with heater and stirrer, a mixture of 115 parts by weight of water

0.15 part by weight of lauryl sulfate (100 parts) 0.5 part by weight of fumaric acid 0.5 part by weight of acrylic acid 1.2 parts by weight of Ealiumpersulfat

"8th-

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0.8 parts by weight of potassium bicarbonate

0.5 parts by weight of dodecylmercaptan

9.25 parts by weight of styrene

6.2 parts by weight of butadiene

30 min. heated to 72 to 74 ⁰ C and then added within 5 to 6 h, the following mixture:

51 parts by weight of styrene

38 parts by weight of butadiene

2.05 parts by weight of cL-methylstyrene

2.5 parts by weight of acrylic acid

After completion of the addition, a conversion of 85 to 90 fo ~. Now 14.8 parts by weight of a 25 $ aqueous urea-formaldehyde-resin solution are added, the batch is further reacted at 85 ⁰ C for 2 h. A 46.2% total solids latex is obtained which was used to impregnate a polypropylene fiber needled felt by the full bath impregnation method.

Example 2

Preparation of the copolymer latex is carried out as in Example 1, but 4.16 parts of a 50 / ° ig ^en aqueous melamine resin solution are added as a coreactive substance instead of the urea resin

 The impregnation was also carried out as in the example

Example 3

Preparation of the Copolytaerlatex as in Example 1, as a coreactive substance but 14.3 parts of a 33% strength ^en aqueous epoxy resin dispersion are added. The treatment of a polypropylene fiber needle felt was thus also by Vollbadimprägnierung.

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example k

Preparation of the copolymer latex as in Example 1, as a coreactive substance, 65 parts of an aqueous 45-D butadiene-Diaminäthylraethacrylat Uopolymerlatex be added with about 7 $ copolymer component. A polypropylene fiber needle felt was also treated by full bath impregnation with this binder Gergerisch

Example 5

(for comparison with the prior art)

Preparation of the copolymer latex as in Example 1, but without the addition of a coreactive substance during the preparation, but only before processing; Impregnation was carried out analogously to the other examples,

Example 6

(not according to the invention)

Preparation of the copolymer latex as in Example 5 », after completion of the polymerization ^, 16 parts of a 50% aqueous melamine resin solution were added and finally after 2 hours at 85 ⁰ C was heated.

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table 6 1 impregnating ) 47.6 warehouse Movie needle felting I-iaß- Tetrapod- total stable festig pile stable exam Ex. firmly- formality ness erho formality No. material- lung salary days N / сш ² (Я grade (Я t> 840 <*) - 0.2 5 46.2 6 850 96 - 0.8 5 1 47.6 6 940 90 - 0.6 5 2 46,75 6 1240 92 - 0.3 5 3 47.0 6 820 95 - 1.5 3 4 47.6 - - 88 - 5 5 mm - 5 (after- comparable coagulated 680 - 1.0 4 wets' Iierung 89 to 24 hours

Claims (1)

- "- 19 6 1 8 6 Erfindunftsanspruch Process for the preparation of a needle felting agent, preferably of synthetic fibers, such as polypropylene fibers, based on carboxylated diene copolymer latices with 1 to 5 $ carboxylated monomers and an aqueous solution or dispersion of 1 to 15, preferably 3 to 8 %, of the total solids content of reacting to the carboxyl groups, for example melamine, urea, phenol, epoxy resin, ethylenediamine or dicyandiamide, characterized in that the reactive substance during the preparation of the copolymer at a Monomerenumsatζ mixed between 85 and 92 % and then the polymerization to nearly 100 $ Sales, but at least up to $ 98 sales will be continued »