CS214891B2 - Method of making the absorption mop - Google Patents

Description

(54) A method for producing an absorbent mop

The invention relates to a process for the production of highly porous absorbent mops composed of a fibrous material substrate and a flexible polymeric binder. Mops are useful for cleaning window panes, floors and similar purposes.

Products of this kind produced by impregnating nonwovens with mechanically foamable acrylic, butadiene nitrile or polyurethane emulsions are already known. The conventional manufacturing method involves the use of special machines and is associated with high production costs for the production of mechanical foams.

In the process according to the invention a textile fiber web · obtained in any manner and possibly mechanically strengthened, for example by needling к promote cohesion fibers, weighing from 50 to 300 'g / m ² was impregnated with an aqueous dispersion comprising, as ^one essential component of heat-coagulable polymer, suitable as a binder for textile fibers, and a volatile liquid suitable as a blowing agent during coagulation by heat treatment. In the heat treatment, the polymeric binder will obtain a porous structure due to the evaporation of the blowing agent, wherein the polymeric binder is bound by a fibrous substrate; the end product thus obtains good absorption properties.

Accordingly, the present invention provides a method for producing an absorbent mop consisting of a fibrous web of textile fibers at least partially on a cellulosic basis of 50-300 g / m ² and impregnated with a polymeric binder, characterized in that the fibrous web is impregnated with an aqueous dispersion containing 100 parts by weight to 00 parts by weight of a thermally coagulable polymer of the type generally used for bonding fibers, up to 120% by weight of a blowing agent consisting of a liquid having a boiling point of 30 ^; up to 80 ° C, which does not dissolve or swell the polymer, the amount of blowing agent being related to the polymer contained,

0.2 to 8 parts by weight of a coagulating agent for coagulating the polymeric binder by heat, optionally 0 to 2 parts by weight of an aqueous dispersion stabilizer, 0 to 5 parts by weight of dyes and solid fillers, 0 to 10 parts by weight of a water-miscible thermosetting resin; and the impregnated web is heat treated at a temperature of 40 ° to SD ° C to coagulate the polymer latex and evaporate the blowing agent, after which the article is washed with water and finally dried and partially crosslinked at a temperature of at least 100 ° C.

The fiber substrate used is made of cellulosic fibers, either natural or regenerated, optionally mixed with synthetic fibers of different chemical compositions. Thus, the textile substrate may be cotton, viscose fibers and mixtures thereof with polyamide fibers, polyester fibers, etc .; such fibrous substrates are particularly suitable according to the invention. The content of cellulosic fibers is necessary since they impart sufficient water-absorbing capacity to the finished product, while fibers of different compositions are suitable for improving the mechanical strength of the product.

Suitable polymers in the form of an aqueous dispersion are those commonly used as textile fiber binders and suitable for thermal coagulation treatment. Particularly suitable are acrylic polymers such as polymers and copolymers of acryloinitrile, esters of acrylic acid, acrylic acid, butadiene acrylonitrile copolymers. The concentration of the polymers in the aqueous dispersion is generally 15 to 60% by weight.

The blowing agent, consisting of one or more organic liquid compounds, should have a boiling point of 30 to 80 ° C and lower than the temperature used for thermal coagulation. The blowing agent must be insoluble in water or only partially miscible with water and compatible with the polymeric binder: practically it should not act on the polymer either as a solvent or as a swelling agent.

Particularly suitable are the following compounds and mixtures thereof:

trichlorofluoromethane,

1,1,2-trichlorotrifluoroethane, n-hexane, trichlorethylene, methylene chloride, n-pentane.

The blowing agent is used in an amount of 20-12% by weight, based on the dry weight of the polymer used as binder. The mixture of the above components, i.e., the binder and the blowing agent in an aqueous medium, further comprises suitable coagulation means capable of inducing the coagulation of the polymer by heat.

Products already known for the coagulation of polymeric latexes such as quaternary polyamines of polyhydroxyalkylenes such as Cartafix 1 from Sandoz, polyfunctional organopolysiloxanes such as WS coagulating agent Bayer, cationic quaternary ammonium salt cationic surfactants such as Rolquat CDM-BC from ROL .

The aqueous dispersion may also contain the following components as auxiliary agents: aqueous dispersions of stabilizers, such as nonionic surfactants, for example polycondensates of ethylene oxide with alkylphenols, or protective cotoids, such as especially suitable polyvinyl alcohol, the amount of stabilizer and amount of coagulating agent generally being the coagulation temperature of the latex is 40 to 70 ° C.

The aqueous dispersion may further comprise a water-miscible resin of a thermosetting type acting as a crosslinking agent and imparting greater rigidity and mechanical strength to the finished product; suitable examples of such resins are methylollated melamine-reductaldehyde resin of the Permafresh MEL type by ROL and similar products such as Aerotex M3 etc., or urea-formaldehyde resin such as Xilocolla 12570 'from Montedison. However, these resins require the presence of acid catalysts to crosslink them.

The aqueous dispersions may further comprise colorants, pigments and various solid fillers.

The aqueous dispersions used for impregnating the textile material preferably have the following composition:

weight parts polymeric binder 15 to 60 stabilizing nonionic surface active means 0 to 2 dye, pigment, solid filler 0 · to 5 a coagulation agent 0.2 to 8 thermoformable resin 0 to 10 acid catalyst for · heat curable resin 0 to 2 water sufficient for Addition to 100 ALIGN!

. The blowing agent is added to the aqueous dispersion in an amount of 20 to 120% by weight, based on the dry weight of the polymeric binder. The mixture is then homogenized by stirring prior to use.

The fibrous substrate is impregnated with the aqueous polymer dispersion in any suitable manner, for example by simple soaking in a bath.

The amount of adsorbed aqueous dispersion of fibrous substrate may be metered and controlled by passing the impregnated substrate between a pair of squeezing rollers: the amount of impregnation composition absorbed should be such that the dry matter content of the finished product is 100-250% with respect to the fiber substrate weight, and 120 to 180%.

The process according to the invention comprises as successive operations after impregnation of the fiber substrate with the above-mentioned dispersion:

(a) heat treatment for thermal coagulation. a polymer latex and to evaporate the blowing agent to obtain a porous structure of the polymeric binder,

(b) subsequent washing of the finished product in water;

c) further heat treatment for drying and partial cross-linking of polymer material ·

The first heat treatment is carried out at a temperature of 40 to 90 ° C, preferably at a temperature of 70 to 80 ° C. It can be carried out using any device, for example in a circulating air furnace or an infrared furnace.

The subsequent washing is preferably carried out in lukewarm water or warm water.

The drying is carried out at a temperature between 100 ° C to 120 ° C, while crosslinking; is carried out at a higher temperature, about 140 ° C. However, these thermal operations can also be carried out simultaneously or at least in one stage.

The process according to the invention produces products having a weight of 100 to 75 g / m @ ² . Further characteristics for good performance are given in the following examples. The following examples illustrate the process of the invention and do not limit it in any way. Parts and percentages are by weight unless otherwise indicated.

Example 1

The viscose fibrous web obtained by the cross-overlaying of fibers, weighing 120 g / m @ ² , is needled with 150 punctures / cm @ 2. It is impregnated in a bath containing:

parts by weight · heat-coagulable acrylic polymer in the form of 40% aqueous · dispersion of Crilat DR 1401 company

Montedison 400 nonylphenol, condensed with 40 moles of ethylene oxide as a 30% aqueous dispersion of Rioclene NF 40 '

ROL 5 blend of 100 parts yellow Velesta 2 GR, 1 part brown Velesta BR and 5 parts red Velesta FGR in the form of an aqueous dispersion of Vestaesta by ACNA 2 47.6% aqueous polyfunctional · polysiloxane · pH 8, density 1 With a cloud point of a 15% aqueous solution at 31 ° C as coagulant WS

of Bayer, diluted with 50 ·% water 5

1,1,2-tidt-lh ^ ll ^ i ^ tretlL ^ c ^^^anan 60

The bath is homogenized by stirring for five minutes using a Lenart stirrer

350 rpm Aqueous dispersion of pH

3,4 · has a coagulation temperature of 57 to 59 ° C before adding the blowing agent. The impregnated web is passed through a 0.5 mm twin roll, producing a pressure of 784.5 kPa to adjust the amount absorbed by the substrate to correspond to 220 g / m 2 of dry matter (meaning the sum of polymer plus auxiliary materials j. Thermal coagulation by heat treatment) In which the blowing agent also evaporates, it is carried out for 7 minutes in a circulating hot air BENZ-type furnace at a temperature of 80 ° C, followed by washing with water at a temperature of 50 to 60 ° C.

Final drying and heat treatment is carried out at 120 ° C for 7 minutes in a circulating hot air oven.

The characteristics of the finished product thus obtained are given in the attached Table I.

Example 2

The fiber web prepared as described in Example 1 is impregnated in the following bath:

parts by weight of butadiene acrylonitrile copolymer in the form of a 50% aqueous dispersion of Elaprim.

D 342 from Montedison 400 nonylphenol condensed with 80 moles of ethylene oxide as a 30% dispersion in water Rioklen NF 80

ROL 10 mixture of 100 parts yellow Velesta 2 GR, part brown Velesta BR and 5 parts red 'Velesta FGR in the form of an ACesta Velesta aqueous dispersion from ACNA 1.5 Cartafix U coagulating agent Sandoz in the form of a 14% aqueous dispersion 140

1,1,2-Thiophthifluoroethan 60

The bath is first homogenized by stirring as described in Example 1 and the pH is adjusted from 8.9 to 4.9 by addition of maleic acid.

The aqueous dispersion having a pH of 4.9 has a coagulation temperature of 46-48 ° C in the absence of a blowing agent.

The following operations were performed as described in Example 1.

The properties of the finished product are given in the attached Table 1.

Example 3

The procedure is as described in Example 1 using an impregnating bath of this composition. ·

Parts by weight

Crilat DR 1401 200

Elaprim D 342 200 ·

Rioclene NF 40 (30% vv vvdd) 5

Pigment Velesta (see Example 1) 1.5

Cartafix U (50% in water) 40 n-hexane 60

The bath is homogenized by stirring as described in Example 1 and the pH is adjusted to 4.9 with maleic acid. The aqueous dispersion at pH 4.9, free of the blowing agent, has a coagulation temperature of 40-42 ° C.

The following operations were performed as described in Example 1,

The properties of the finished product are given in the attached Table I.

EXAMPLE 1 a d 4

The procedure is as described in Example 1 using an impregnating bath of the following composition:

Parts by weight

Crilat DR 1401200

Elaprim D 342200 ·

Rioclene NF 40 (30% in water) 5

P'gment Velesta (see Example 1) 1.5

Permafresh MEL from ROL (methylated melamine-formaldehyde resin with 83% active ingredient) 5

Cartafix U (50% in water) 40 mixture of 1,1,2-trichlorotrifluoroethane trichlorofluoromethane and trichlorethylene in a weight ratio of 60: 10: 30 with a boiling point of 43 ° C 60

The bath is homogenized by stirring and the pH is adjusted to 4.9 with maleic acid. The aqueous dispersion, pH 4.9, in the absence of a blowing agent, has a coagulation temperature of 43-45 ° C. ·

The following operations were carried out as described in Example 1.

The properties of the finished product are given in the attached Table I.

Example 5

The procedure of Example 1 is followed using an impregnating bath of the following composition:

Parts by weight

Crilat DR 1401200;

Elaprim D 342200

Rioclene NP 40 (30% in water) 5 Velesta pigment (see Example 1) 1.5

Cartafix U (50% in water) 40 n-pentane 60

The following operations were performed as described in Example 1.

The properties of the finished product are given in the attached Table I.

Example 6

The procedure is as described in Example 1 using an impregnating bath of the following composition:

Parts by weight

Crilat DR 1401400

Rioclene NF 40 (30% in water) 5 pigment Velesta (see Example 1) 1.5 coagulating agent W.S.

diluted with 50% water5 a mixture of 1,1,2-trichlorotrifluoroethane and methylene chloride in a molar ratio of 50:50 (boiling point 37 ° C) 60

The bath was homogen'zuje mixing as described in Example 1. The aqueous dispersion of hodnoiě pH 3.4 and in the absence of blowing agent) has a coagulation temperature of 58 to 58 ^o _C;

The following operations were carried out as described in Example 1.

The properties of the finished product are given in the attached Table I.

The attached table shows a comparison of the value of the formulations according to the invention in comparison with the known products which are successfully used on the Italian market.

The properties of the products according to the invention are tested in the following ways:

1) Determination of capillarity

Method: i

A rectangular 2X15 cm sample is cut. Two notches are made at a distance of 5 cm and 10 cm. The test sample is immersed in a length of 5 cm in demineralised water at 20 ° C to avoid contact with the container edges. The time taken to wet the test sample to a height of 5 centimeters above the liquid level is measured. The test is performed with five samples.

Evaluation of results: The capillarity value shall be expressed by indicating the mean time required to wet the test sample to a height of 5 cm above the surface of the liquid.

2) Determination of water absorption

Method: Cut a square test specimen 5X5 cm side. After conditioning for 60 minutes in a drier containing calcium chloride, the test sample is weighed. It is then immersed in demineralised water at 20 ° C and left for 10 minutes. Remove the sample, allow to drain on the sieve for two minutes. Then weigh. The test is performed with five samples.

The bath is homogenized by stirring and the pH is adjusted to 4.9 with maleic acid. The aqueous dispersion, 0 'pH 4.9, in the absence of a blowing agent, has a coagulation temperature of 55-57 ° C.

Evaluation of results: Water absorption is expressed as a percentage weight gain.

3) Stability in normal washing

Method: Cut a 5 x 5 cm square sample. Condition for ¹ BO minutes in an oven containing calcium chloride and. then weigh. The test samples are placed in a suitable steel container containing an aqueous solution of 5 g / l household detergent and 50 stainless steel balls of 6 mm diameter. A five hour wash at 90 ° C is performed. The test samples are repeatedly rinsed with running water, dried at 80 ° C, conditioned for 60 minutes in an oven and weighed. · The test is performed on five samples.

Evaluation of results: Resistance to normal washing is judged by the test sample and any changes that may occur during the wash. Grades 1, poor, up to 10, · very good, compared to a suitable standard grade, also indicate% weight loss for evaluation.

4) Break test

Method: Pipette 1 ml of water onto a 20X30 cm glass plate. The 15X15 cm mop to be tested is placed on the deposited water and streaks, circles and opacity are observed, if any. Perform at least 5 tests, each with a dry mop.

Evaluation of the results: The expansion test is evaluated by the formation of bands, circles, opacity and the like and is graded 1, poor, up to 10, very good.

5) Determination of pilling

Equipment: Abrasion testing instrument Branca, Milan.

Method: Cut a 20 x 20 cm square sample. The sample is clamped onto a suitable nylon polyamide holder and brush. at a pressure of 4.9 kPa / cm ^2, rotate on the sample until hair formation is observed. · At least three samples shall be tested. .

Evaluation of results: Pilling resistance is expressed by the evaluation of hair consistency, indicating whether the lumps formed are large, small or very small, and with marks of 1, poor, · to · 5, very good, compared to an appropriate standard scale. The number of cycles required to induce sample changes is also calculated.

The tensile strength shall be tested in a standardized manner by UNI 5116..

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Claims (5)

Subject A process for the production of an absorbent mop consisting of a fibrous web of textile fibers at least partially on a cellulosic basis weighing 50 to 300 g / m ² - and impregnated with a polymeric binder, characterized in that the fibrous web is impregnated with an aqueous dispersion containing 100 parts by weight 15 to 60 parts by weight of a thermally coagulable polymer of the type generally used for bonding fibers; 20 to 120% by weight of a blowing agent consisting of a liquid having a boiling point of 30 to 80 ° C, which neither dissolves nor swells the polymer, the amount of blowing agent being in relation to the polymer contained therein, 0.2 to 8 parts by weight of a coagulating agent for coagulating the polymeric binder by heat, optionally 0- to 2 parts by weight, aqueous dispersion stabilizer, 0 to 5 parts by weight of dyes and solid fillers, 0 to 10 parts by weight of water-miscible resins OF THE INVENTION and the impregnated web is heat treated at 40 to 90 ° C to coagulate the polymer latex and evaporate the blowing agent, then the product is washed with water and finally dried and partially thickened at a temperature of at least - 100 ° C. 2. The method of claim 1, wherein the thermally coagulable polymer is selected from the group consisting of polymers and copolymers of acrylic acid esters, acrylic acid, acrylonitrile and butadiene-acrylonitrile copolymer. 3. The process of claim 1, wherein the blowing agent consists of one or more compounds selected from the group consisting of trichlorofluoromethane, trichlorotrifluoroethane of the formula CC12F-CCIF2, n-hexane, trichlorethylene, n-pentane and methylene chloride. 4. A method according to claim 1, wherein the fiber substrate is impregnated with an amount of aqueous dispersion corresponding to an amount of dry matter per substrate of from 100 to 250% by weight. 5. The process of claim 1 wherein the polymer is coagulated and the blowing agent is evaporated at a temperature of 70-80 ° C.