DE1129449B - Process for the production of a fiber fleece - Google Patents

Description

The invention relates to a method of manufacture a non-woven fabric that is resistant to chemical cleaning and dry cleaning. The fiber fleece can also be used to manufacture objects of either flat or three-dimensional shape As an insulating material or the like. Can be used.

Urea-formaldehyde and melamine-formaldehyde condensates are used as binders for the fibers known in nonwovens, but when used alone they provide stiff products that are used in the manufacture of Textiles are unsuitable because they drape poorly and feel rough. Furthermore, the so produced Nonwovens are not satisfactorily processed into garments that are more or less often need to be bleached. Examples of this are intermediate layers for collars and cuffs Shirts, especially those used for summer clothing, which are relatively openly woven types. The bleaching of such articles with the commonly used hypochlorites leads to discoloration and to decrease the strength of the fabrics, especially if heated or ironed after bleaching will. The use of such condensates in connection with certain addition polymers, as described in U.S. Pat. No. 2,823,142, provides a nonwoven which, although initially has a soft feel and the desired draping properties, but is chemical Cleaning the fleece gradually removes the addition polymer. As a result, the soft feel and good drape properties are lost, and the product decreases, although its fibers are still bound by the thermosetting condensate, have a rough grip and do not fall more in the way you want. In addition, the products obtained according to this patent show a Yellowing and a decrease in strength when bleached.

The invention relates to a process for the production of a nonwoven fabric which is resistant to chemical cleaning and dry cleaning, which is characterized in that a nonwoven fabric formed from fibers in a random layer is impregnated with an aqueous dispersion which, as the disperse phase, is a mixture of (1) 2 to 60 percent by weight a water-insoluble copolymer with a Γ-value not above 17 ° C of 1 to 10% acrylic acid amide and / or methacrylic acid amide and 90 to 99% monomeric acrylic acid nitrile or methacrylic acid nitrile, acrylate or methacrylate and (2) 5 to 17% of one in water Contains dispersible, thermosetting, resin-forming aminoplast condensate, whereupon the IMPRA process of manufacture
a fiber fleece

Applicant:

Rohm & Haas Company,
Philadelphia, Pa. (V. St. A.)

Representative: Dr.-Ing. H. Ruschke, Berlin-Grunewald,

and Dipl.-Ing. K. Grentzenberg,
Munich 27, Pienzenauer Str. 2, patent attorneys

Claimed priority:
V. St. v. America 9 April 1958 (No. 727 245)

Vincent John Moser, Willow Grove, Pa.,

and Benjamin BerrylKine, Levittown, Pa. (V. St. A.),

have been named as inventors

gnosed fleece dried at a temperature above the Γ value of the polymer and then the dried fleece is heated to 110 to 350 ° C.

The presence of the amide groups in the addition copolymer leads to during curing a reaction with the methylol units of the aminoplast condensate. Surprisingly it was found that the use of the amide copolymers in conjunction with the aminoplast condensate in the specified proportions leads to the tendency of the nonwovens to discolour and loss of strength if after bleaching with chlorine-containing agents such as those commonly used hypochlorites used in the textile industry. This is therefore surprising because the copolymer contains nitrogen atoms which, as expected, the Should increase the tendency to destruction by chlorine.

The acrylic copolymers used can be acrylic or methacrylic acid esters with benzyl alcohol or contain cyclohexanol.

The acrylate or methacrylate of component (1) is preferably derived from acrylic or methacrylate

209 580/413

acrylic acid and an alcohol having 1 to 18 carbon atoms.

The proportions of acrylonitrile and methacrylates of lower alcohols such as methyl methacrylate and ethyl methacrylate should be such that the r _r value of the polymer is preferably not above 5 ° C, even better not above -10 ° C, for the best possible drape properties and the softest To achieve grip. It is essential that the copolymer contain no chlorine. It is also important that the interpolymer contain no more than 89 percent by weight methyl acrylate or ethyl acrylate or both together. It is essential that the proportion of aerylic acid amide or methacrylic acid amide or a mixture of these two is not greater than 10 percent by weight, because it has been found that copolymers containing a larger proportion of the amide constituent entMischpolymerisats and condensate are applied. The catalyst can be used in an amount of 0.25 to 0.5 percent by weight of the aqueous dispersion when added directly to the dispersion. If it is applied separately, it is preferably used in such an amount that it ^{corresponds to 0.5 to 2 1} Vo of the weight of the condensate used. The acidic catalyst can either be an acid itself or it can be a potentially acidic substance that acts as a latent catalyst and releases acid when heated. Examples are ammonium chloride, diammonium hydrogen phosphate, zinc fluoroborate, zinc perchlorate, or a salt of an amine, such as the hydrochloride of monoethanolamine, diethylamine, triethylamine, 2-methyl-2-aminopropanol-1 and the like.

As stated above, the copolymer contains a large number of amide groups, by means of which it at Warming with the aminoplast in the presence or

hold, form a binder that is extraordinary

strongly swells and even disintegrates. Preferably, the absence of a suitable catalyst is an insoluble amount of aerylic acid amide and / or methacrylic or infusible. Thus, the cured fiber product has resistance to cleaning, dry cleaning, various chemicals and heat. The fiber webs according to the invention can be heated to moderate temperatures without their being discolored, increased in stiffness or undesirably disintegrated. They are characterized by excellent ironing resistance, although they are not 30

acid amide in the copolymer 2.5 to 5 percent by weight. It was found that this little one Amount of aerylic acid amide in the copolymer is the most favorable combination of insolubility, Heat resistance, solvent resistance, softness and resistance to change of Effect on handle and drape properties after dry cleaning.

A low molecular weight reaction product can be used as the aminoplast condensate of component (2) from formaldehyde and melamine or N, N-dimethylmelamine or dimethoxymethylmonomethylolamine or furthermore urea, thiourea, biuret or the like or one modified with alcohol, in the heat hardening melamine-formaldehyde condensate can be used.

As formaldehyde-urea condensates, some of Ν, Ν-ethylene urea, N, N'-ethylene urea

35 get sticky. The binders according to the invention apparently also have a very versatile adhesive capacity, since they are not only applied to hydrophilic fibers such as cotton, cellulose rayon and the like, but also to hydrophobic types of fibers such as nylon and, in particular, polyamide fibers, vinyl resins, e.g. B. copolymers of vinyl chloride with vinyl acetate or with acrylonitrile, polymers of 70 to 90% acrylonitrile with other monomers, such as vinyl chloride, vinyl acetate, one of the vinyl pyridines,

substance, Ν, Ν'-dimethylurea, N, N'-diethylurea, 40 such as 2-vinylpyridine, or mixtures of such auxiliary N, N'-dimethoxymethylurea, Ν, Ν-dimethoxy monomers, polyesters, such as polyethylene glycol teremethyl urea, Ν, Ν'-diethoxyethyl urea, tetraphthalate, and cellulose esters, such as cellulose acetate, methoxymethyl urea and tetraethoxyethyl urea, cellulose acetate propionate, cellulose acetate butyrate, etc.,

fabric can be used.

The degree of condensation of these resin-forming aminoplast condensates is preferably so great that they are still soluble in water or in it by themselves colloidal solutions are dispersible.

The quantitative ratio of the addition copolymer containing amide groups to that in the Heat curable resin-forming condensate is between 5: 1 and 19: 1, preferably between 9: 1 and 10: 1 (weight units). At a ratio of 5: 1, it is advisable to use copolymers with a to use a larger proportion of a plasticizing acrylate or methacrylate to achieve the desired ensure a soft grip. On the other hand, at a ratio of 19: 1, the harder copolymers with Γ, values from 5 to can be used at about 17 ° C without creating an overly stiff, rough handle.

The impregnation of the fiber product can optionally be made in the presence of an acidic catalyst. The acidic catalyst can then either added to the aqueous dispersion containing the copolymer and the condensate or separately on the nonwoven fabric before or after the action of the aqueous dispersion of the excellent adhesion. Because of the characteristic adhesion of the binder according to the application The nonwovens are excellent on both hydrophilic and hydrophobic fiber types Marked for resistance to roughening and abrasion. The binder can be dried and then can be hardened to an insoluble and infusible state, so that the bond is even under very much strong heat is not destroyed. The nonwovens containing the binder also have the advantage that they are in the moist state or during the first drying, but before the complete Drying, can be permanently embossed. This can already be seen from the fact that during drying on a suction device through which the excess water is sucked off the nonwoven fabric, the pattern of the screen remains indelibly imprinted on one side of the product and through itself Calendering can no longer be destroyed under normal conditions and temperatures. If also the binder can optionally preferably be applied to parts of the nonwoven fabric, e.g. B. on one or both sides of the same, it is nevertheless characteristic that one is practically uniform Distribution can be achieved easily because the binding

5 6

medium after the original distribution only one turns, in which the thermoplastic nature

has little effort to be harnessed while drying on the fibers themselves; and

to wander the surfaces. of course, such wool-like fibers can be

The hardened and insoluble binding with relatively non-sticky

Medium are used by water or organic solvent 5 fibers such as cellulose, nylon, wool, etc.

medium even at deformation temperatures.

The Γ, value mentioned here is the so-called preforms or mold inserts for the production of transition temperature of the 2nd order or freeze-stamping molded objects from different thermosetting temperatures, which can be used by applying the rigid module against bar resins, as in following aus- io the temperature is determined. A convenient seducer is set forth. The binders show drive to the determination of the rigid modulus and furthermore no cold flow and are flow resistant even at higher transition temperatures by I. Williamson in temperatures, whereby a ver British Plastics, 23, p. 87 to 90, 102 (September pushing the fibers or Threads in the finished 1950). The Γ value used here for fiber fleeces - even at elevated temperatures 15 was determined at 300 kg / cm ² , during the subsequent deformation - practically full. or reinforcing inserts or preforms used to be block copolymers. The binder according to the invention can be given

The molecular weight of the invention, if necessary in connection with other binders,

applied polymers should be used between 100,000 and like glue.

10 million treasures. Optionally, the aqueous dispersion of the

The fibers are in the form of a so-called polymer and condensate also a wetting agent Fleece, in which they are randomly distributed. The fleece contained in order to penetrate the fiber fleece can be made by carding if the 25 promote, and it can also be either a foam fiber are accessible to a carding process. The means to keep the binder in the finished product Nonwovens can also be converted into a foamed state by deposition of the fibers, or a dewatering a stream of air. contain foaming agents if the ingredients

The fleece can be made of natural fibers, such as. B. the aqueous dispersion has a tendency to foam

Jute, sisal, ramie, hemp and cotton, or syn- 30 and foaming is undesirable. as

synthetic fibers, such as B. rayon, nylon, wetting agents can be used, for. B. the sodium salt of di-

Vinyl resin, polyacrylic acid nitrile or polyethylene octyl succinate, as a foaming agent z. B. sodium soaps,

glycol terephthalate fibers, or mixtures formed including sodium oleate, and as defoaming

be. using octyl alcohol or certain silicones

If necessary, two or more of these can turn.

Nonwovens are layered one on top of the other, in particular the quantitative ratio of inventive for the production of thermal insulation. Thereby binding agent to the weight of the fiber component may alternate layers of carded fibers of the fibrous product depending on the nature of the product are stacked so that their fiber-desired product fluctuates greatly. For the Orientation directions angles of 60 or 90 ° with- 40 Manufacture of preforms that are shaped against each other form. stands to be transferred are preferred

The choice of fiber depends on the intended 2 to 10% of the binder according to the invention Intended use of the product. So are z. B. based on the weight of the fibers used. For the Silicic acid-like fibers for the production of shaped production of insulating compounds can be used Items of exceptional strength worth 45 amount of binder in the lower part of the specified fully. Should the bonded nonwovens be used for filtering areas if the binding agent is predominant For purposes of use, fibers are made up against the surface or surfaces of the sample Acid and alkali-resistant resins applied or in conjunction with others preferred, e.g. B. Polymers that have a high binder content should be used. The watery one of acrylonitrile or vinyl chloride, or 50% dispersion of the poly containing the amide groups such highly halogenated resins as polytetra- merizate is preferred in a concentration of fluoroethylene or poly (chlorotrifluoroethylene). Timmed for 20 to 40 weight percent solids content Purposes it may be desirable to bring the fiber.

Nonwovens made from a mixture of fibers of different types. The nonwoven fabric can be 10 to 200 percent by weight Ways to manufacture. One example is the use of 55 copolymer condensate binders on the based on thermoplastic fibers with adhesive nature, weight of the fibers included, depending on the in a mixture with other fibers that have such an intended use of the product. When the binding adhesiveness is missing. One of such a mixture means mainly to connect the fibers Existing nonwoven fabric can be applied to the corresponding one cohesive unitary structure Temperature are heated to serve the adhesive 60, which has the greatest possible porosity in To make fibers sticky and in this way a connection with the least possible change in the Connection of the fiber in the product is intended to maintain both the natural feel of the fiber by as well as by the binder according to the invention 10 to 50 percent by weight solid binder to which means to effect. The fiber obtained in the U.S. Patent can be used, with the 2 866 256 described flaky, wool-like 65 smaller proportions of course the largest possible Fibers can also be used to produce the fiber porosity and a minimum of change in the fleece can be used. Such wool-like natural fiber feel is achieved, although also with Fibers can increase the proportions in this area for the production of nonwovens

2 parts of tert-octylphenoxypolyathoxyethanol with about 35 oxyethylene units (emulsifier and dispersant),

0.4 parts octylphenoxyethoxysodium sulfate (wetting agent),

2.5 parts of dimethylol-N, N'-ethylene urea

0.1 part silicone antifoam agent

contains, up to a moisture absorption of about 600%

Porosity is largely retained and the grip
the fiber still predominates. The
Products can be used for many sanitary purposes,
z. B. as table napkins, bibs, tablecloths, medical cover sheets, removable table cloths, blankets
and as surgical drapes and poultices. It is characteristic of what has just happened
specified proportions of binders used,
that practically no so-called "window pulling" occurs, that is, the gaps between 10% of the weight of the fiber are impregnated. The fleece will remain open to the fibers, so that a very porous product, dried at 107 ° C. for 1.5 minutes and voluminous for 1.5 minutes, is formed. Of course it can be hardened at 177 ° C. The obtained fleece has a Ge-density of the product due to the application of pressure weight ratio of fiber to binder of about in different strengths before or in many cases ■ 33:67. It is very porous and has a soft, even after the hardening of the product affects 15 elastic grip. The fabric can be hypochlorite, solution bleached and then ironed. Nonwovens which contain 40 to 150 percent by weight of the binder without being discolored to any significant degree can usually lose their strength for or for the fibers. Garments for the production of supportive (b) The process of part (a) is repeated with »Pyrex« interlayers for coats, suits, etc. or for 20 fiberglass, only the carded production of outerwear such as blouses, shirt fabrics weighs 0.17 g / dm ² , and impregnation with the etc., can be used. The ones from these tissues
Manufactured garments do not need to be ironed
or to be pressed to their appearance, their shape
and its handle is obtained after washing, machine 25, which is extremely porous and soft, cleaning and dry cleaning and drying but is coherent. to regain. Except for general household and clothing use like those here
As mentioned, the fiber products according to the invention, which contain 10 to 100 percent by weight of binder, 30 of an identical aqueous dispersion based on the weight of the fiber, contain 25.0 parts of an emulsion copolymer

10% n-butyl acrylate and 89% ethyl acrylate as well 1% methacrylic acid amide and the same aminoplast. A porous, soft and cohesive-35 of the fleece is obtained. It can be bleached with hypochlorite solution and then ironed,

aqueous dispersion takes place up to a moisture absorption of 300%, whereby a weight ratio Fiber to binder of 53:47 in the finished web

Example 2 The procedure of Example 1, (a) is followed with

various technical uses as wipes, lining material for packaging purposes, as Filters and as protective covers and seals for machines can be found.

Nonwovens containing 100 to 200 percent by weight of binder, based on the weight of the fiber, are particularly suitable for technical purposes where durability and wear resistance are desired are e.g. B. as seals, protective covers, 40 filters, etc. The products that are 20 to 200 percent by weight of the binder according to the invention, based on the weight of the fiber, can be used as Layers, either as intermediate or basic

without discoloring to any significant degree or losing the strength of the fibers.

Example 3

The procedure of Example 1, (a) is repeated with an aqueous dispersion identical to that of 25.0 parts of an emulsion copolymer

layers, for plastic films and foils made of poly- 45 80% ethyl acrylate, 18.5% 2-ethylhexyl acrylate and ethylene, nylon, etc. or, for textile fabrics, contains 1.5% methacrylic acid amide. An extraordinary one well bonded fleece is obtained which is highly resistant to solvents and heat.

woven, braided, knitted, knotted or felted nature can be used.

The nonwovens connected to the binders

It can be bleached and tarnished with hypochlorite solution

can also be ironed as heat or sound insulation material, 50 closing without it being in

as permeable membranes in storage batteries or electrolytic capacitors, as cushions or cushioning material used for upholstery purposes, etc. The following examples illustrate the invention. Unless otherwise specified, all parts and percentages are units of weight.

discolored to a significant extent or the fibers lose their strength.

Example 4

An air-deposited random non-woven fabric composed of 50 parts of white viscose fiber and 50 parts dyed acrilan fiber (polymer from about 85 to example 1 90% acrylonitrile) (both fibers 3 denier, 3.8 cm

Pile), which weighs about 0.592 g / dm ² , is supplied with a

(a) A carded fabric composed of 75 parts of Vis- 6o aqueous dispersion, the kosef asern to 100 parts (3 denier, 2.5 cm stack) and 25 parts
bleached cotton (medium strength, 2.4 cm long) with
a weight of 0.254 g / dm ² with a
aqueous dispersion based on 100 parts

25th

25.0 parts of an emulsion copolymer of 5% methacrylic acid amide and 95% butyl acrylate,

Parts of an emulsion polymer made from 95% n-butyl acrylate and 5% methacrylic acid amide,

2 parts of tert-octylphenoxypolyethoxyethanol with about 35 oxyethylene units (emulsifier and dispersant),

2.5 parts urea-formaldehyde-methanol condensate,

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0.5 parts diammonium phosphate,
0.5 parts octylphenoxyethoxynatrium sulfate (wetting agent)
0.2 parts silicone antifoam

contains, impregnated at about 300 ^fl / o moisture absorption. The fleece is dried at 107 ° C. for 1.5 minutes and cured at 177 ° C. for 5 minutes. Product: 55 parts fiber / 45 parts binder; good cohesion, porous; soft, textile-like handle. It can be bleached with hypochlorite solution and then ironed without discoloring to any significant degree or losing the strength of the fibers.

Example 5

A random non-woven fabric made of nylon fibers (50 "/" 10 denier, 50% 3 denier, all 3.8 cm staple), which is obtained by air deposition and ^{weighs about 0.423 g / dm 2} , is treated with an aqueous dispersion of 100 parts

25 parts of an emulsion copolymer of 5% methacrylic acid amide and 95% n-butyl

acrylate,
2 parts of tert-octylphenoxypolyethoxyethanol with about 35 oxyethylene units (emulsifier and dispersant),

3.5 parts of methylated hexamethylolmelamine,
0.5 parts diethanolamine hydrochloride,
0.5 part of octylphenoxyethoxysodium sulfate (wetting agent

middle),
0.2 parts silicone antifoam

contains, impregnated with a moisture absorption of about 200%. It is dried at 107 ° C. for 1.5 minutes and cured at 177 ° C for 3 minutes. Product: 55 parts fiber / 45 parts binder; soft, elastic, resistant to cleaning and dry cleaning. The fleece can be bleached without discoloration and then ironed will.

Example 6

The procedure of Example 5 is followed with air-deposited webs made from the following fibers repeated:

(1) 100% regenerated cellulose (2.0 denier, 3.8 cm stack), 0.678 g / dm ² , carded fleece,

(2) 55% nylon 66 polyamide fibers and 45% regenerated Cellulose, both 5 denier, 4.44 cm stack,

(3) 100% cotton (card waste, loose fibers and yarn) 1.36 g / dm ² , carded fleece,

(4) 35% cotton, 65% polyethylene glycol terephthalate fiber, 0.423 g / dm ² , carded fleece.

The nonwovens can be bleached without significant discoloration and then ironed.

Example 7

The procedure of Example 5 is repeated, with 4 parts of one in place of the urea condensate Trimethylolmelamine can be used. A cohesive fleece is obtained without significant discoloration can be bleached and then ironed.

Claims (5)

PATENT CLAIMS: 1. A process for the production of a nonwoven fabric which is resistant to chemical cleaning and dry cleaning, characterized in that a nonwoven fabric formed from fibers in the active position is impregnated with an aqueous dispersion which, as a disperse phase, is a mixture of (1) 2 to 60 percent by weight of a water-insoluble one Copolymer with a ly value not above 17 ° C, from 1 to 10% acrylic acid amide and / or methacrylic acid amide and 90 to 99% monomeric acrylonitrile, methacrylonitrile, acrylate or methacrylate and (2) 5 to 17% of a water-dispersible, thermosetting, Contains resin-forming aminoplast condensate, whereupon the impregnated fleece is _{dried at a temperature above the T r} value of the polymer and then the dried fleece is heated to 110 to 350 ° C. 2. The method according to claim 1, characterized in that the fleece is made of natural Fibers such as B. jute, sisal, ramie, hemp and cotton, or synthetic fibers such. B. Rayon, nylon, vinyl resin, polyacrylonitrile or polyethylene glycol terephthalate fibers, or mixtures are formed. 3. The method according to any one of claims 1 and 2, characterized in that the Acrylate or methacrylate of component (1) of acrylic or methacrylic acid and an alcohol with 1 to 18 carbon atoms. 4. The method according to any one of claims 1 to 3, characterized in that the aminoplast condensate of component (2) a low molecular weight reaction product of formaldehyde and melamine or N, N-dimethylmelamine or Dimethoxymethylmonomethylolamine or further urea, thiourea, biuret or the like. Or a Melamine-formaldehyde condensate that has been modified with alcohol and cures in the heat is used will. 5. The method according to claim 4, characterized in that as formaldehyde-urea condensates which of Ν, Ν-ethylene urea, N, N'-ethylene urea, Ν, Ν'-dimethylurea, N ₅ N '- diethyl urea, N ₅ N' - Dimethoxymethylurea, Ν, Ν-dimethoxymethylurea, N ₅ N'-diethoxyethylurea, tetramethoxymethylurea or tetraethoxyethylurea can be used. Considered publications:
U.S. Patent No. 2,725,309;
American Dyestuff Reporter, 46, pp. 437 to R 442. © 209 580/413 5.