DE1148521B - Process for the production of a soft fleece - Google Patents

Description

GERMAN

PATENT OFFICE

R27969IVc / 8k

REGISTRATION DATE: MAY 12, 1960

NOTICE
THE REGISTRATION
AND ISSUE OF
EXPANDED: MAY 16, 1963

Linear, permanently thermoplastic copolymers are known as binders for nonwovens (cf. US Pat. No. 2,837,462). However, they do not give the products any strength when washed at higher temperatures or when dry-cleaned. It is also already known that addition polymers containing small amounts of acrylic acid amide or methacrylic acid amide can be used in conjunction with heat-curing condensates of aminoplast or epoxy resins to bind the fibers in nonwoven textiles. The use of condensates in connection with the amide polymer was necessary to produce a resistance to washing and dry cleaning, because by applying the amide-containing polymer to the nonwoven fibrous webs even after exposure to high temperatures, e.g. B. of 150 ⁰ C, a resistance of the bonded webs obtained both to washing and to dry cleaning could not be achieved. For example, a binder combination of a polyester and a water-soluble melamine-formaldehyde condensation product has been used for nonwovens (cf. British patent specification 774 620). Since the polyester itself does not contain any reactive groups that are necessary for curing, both components of the binder must be used to achieve the desired properties. In contrast, according to the present invention, even the sole use of a water-insoluble copolymer and subsequent heating leads to a product which is resistant to washing and dry cleaning.

According to the invention, a modified amide-containing addition copolymer is used as a binder used for the fibers of nonwoven products, resulting in nonwovens which, according to the Cure has sufficient resistance to washing for most practical purposes and dry cleaning with chlorinated hydrocarbons and which also compared to normal Washing processes with modern detergents are resistant without putting one in the heat hardening condensate resin, e.g. B. an aminoplast or polyepoxy resin, in addition to the amide containing Polymer must be used.

The inventive method is characterized in that the material with 15 to 50 percent by weight Binder, based on the total weight of binder and fibers, in the form of an aqueous Dispersion is treated, the binder being a process for producing a soft fleece

Applicant:

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

Representative: Dr.-Ing. H. Ruschke, patent attorney, Berlin 33, Auguste-Viktoria-Str. 65

Claimed priority: V. St. v. America May 13, 1959 (No. 812 802)

Vincent John Moser, Abington, Pa. (V. St. A.), has been named as the inventor

consists of a water-insoluble copolymer, the units of which are 4 to 6 percent by weight Methacrylic acid amide units, 5 to 15 percent by weight vinyl alcohol units, 1 to 45 percent by weight Vinyl acetate and 46 to 90 percent by weight of an ester of acrylic or methacrylic acid with an alkanol containing 4 to 18 carbon atoms.

Suitable acrylic and methacrylic acid esters are, for. B. butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and methacrylate, n-octyl acrylate or methacrylate, Dodecyl acrylate, hexadecyl acrylate and octadecyl acrylate.

The fleece impregnated with the binder is dried to melt the copolymer and bond the fibers and then the fibrous product is ^{heated to a temperature of 99 to 400 °} C. in order to make the bonded fibrous product resistant to washing and dry cleaning.

It has been found here that the methacrylic acid amide is not completely replaced by acrylic acid amide can be replaced. The polymers produced with acrylic acid amide do not provide the resistance compared to washing and dry cleaning with methacrylic acid amide copolymers is obtained.

The monomers from which the polymers are prepared are selected so that a Copolymer with an apparent second

309 580/399

Transition temperature, which has been designated here with "7 *", of not above 20 ⁰ C is obtained. The value of Ti given here denotes the transition or bending temperature, which is found by plotting the rigid modulus against the temperature. A suitable method for determining the rigid modulus and the transition temperature is from I. Williamson in "British Plastics", 23, pp. 87 to 90, 102 (September 1950),

is obtained, a reagent is added to the copolymer for partial hydrolysis of the vinyl ester, the introduction of the necessary vinyl alcohol units into the polymer to be produced causes. This hydrolysis can take place in either acidic or alkaline areas, however alkaline conditions are preferably used. To achieve hydrolysis it is necessary such an amount of an alkaline reagent,

has been described. The values given here ₁₀ such as sodium hydroxide to be added, which is the same as in vinyl

of Ti have been determined to be 300 kg / cm ² .

The polymers which are used according to the invention as binders can be linear addition polymers. You will be following a procedure

7 to 50 percent by weight of a vinyl ester such as vinyl acetate and 46 to 90 percent by weight at least an ester of acrylic or methacrylic acid with

alcohol units to be converted proportion of the vinyl ester units corresponds stoichiometrically. To adding the alkaline reagent, the polymer dispersion for one to use up the

obtained, in which first a copolymer of _i5 alkaline material is heated to about 66 4 to 6 percent by weight methacrylic acid amide and up to 93 ⁰ C for sufficient time, which is determined by checking the pH

the dispersion can be determined. The time required is the opposite of that used Temperature and is determined by the proportion of the amount

a (Ci- to Cie-) alkanol is produced. These 20 generating vinyl alcohol units are determined. at

small batches, a time between about 15 and 200 minutes can be used.

After the hydrolysis, the polymer dispersion can be diluted with water. Usually a

Mixture of the same, in conjunction with a free 25 dispersion applied to the fleece, which between Free radical generating catalyst is used, about 5 and 60 weight percent solids ent

Copolymers can be prepared by customary emulsion polymerization processes be prepared in which a suitable emulsifier, e.g. B. a nonionic or anionic emulsifier or a

which can optionally be a component of any of the known redox systems. Usable Emulsifiers are e.g. B. sodium auryl sulfate or tert-Octylphenoxypolyäthoxyäthanole, the approximately Contain 10 to 50 oxyethylene units per molecule. The amount of emulsifier can be between 0.5 and 6% of the monomer weight. Any free radical generating catalyst, such as azodiisobutyronitrile, tert-butyl hydroperoxide ammonium or potassium persulfate, can behave. The preparation of the copolymers and the dispersions therefrom is not the subject of these Invention.

The copolymer can also contain other monomers, such as styrene, vinyl toluene, vinyl chloride, acrylonitrile or methacrylonitrile, contained in small amounts.

The fibrous webs can be prepared by known and 35 methods, e.g. B. by carding, grooming or by deposition from a suspension of the fibers

be turned. The proportion used, which is in air, to be produced.

Catalyst can contain between 0.1 and 2% of the mono-

merenweight lie. fibers such as cotton, rayon, jute, ramie

The 40 and linen fibers used as binders according to the invention; Fibers made from cellulose esters, such as polymers, can also be grafted or block-mixed cellulose acetate; Silk, wool, casein and other polymers, with one or more, but protein-like fibers; Fibers made from polyester, like not all of the monomers initially polymerized poly (ethylene glycol terephthalate); Fibers made from poly- and then one or more of the other mono-amides such as nylon; Vinyl resin fibers such. B. from mers mixed with the polymer obtained first 45 a copolymer of vinyl chloride and vinyl polymerized. Methacrylic acid amide can acetate, from acrylonitrile polymers that 80 to initially homopolymerized or with one or
with several, but not with all of the others
Mixed monomers which are to be contained in the finished copolymer are copolymerized 50
be what the last monomer or the
added last monomers and with the first
produced homopolymer or copolymer
be copolymerized or grafted on. That

The same method can also be used in reverse series, an acid catalyst can be used in the sequence, so that the methacrylic acid application to the fibrous web incorporates amide on a previously prepared homopolymer
or copolymer of the other monomer units is grafted on. Again, you can
several monomeric units in succession 60
be introduced so that the methacrylic acid amide
at the beginning, during an intermediate stage
or can be introduced at the end.

After the production of the linear addition

95 percent by weight acrylonitrile, and finally silica-containing fibers, such as glass and mineral wool.

The aqueous dispersion of the water-insoluble copolymer proposed according to the invention is applied to the nonwovens by known methods, e.g. B. by spraying, dipping, transferring with the help of rollers and the like. Of the

be, or the acid catalyst can before or after the application of the copolymer to the fibrous web are applied.

The proportion of the copolymer applied to the fleece is measured in such a way that the Copolymer, based on the total weight of the copolymer and fibers, 15 to 50 percent by weight matters. After applying the aqueous

copolymer after the emulsion polymer dispersion of the water-insoluble copolymer sationsverfahren, in which the quantity used is the impregnated or saturated fleece in the case of spatial proportions usually be dimensioned in such a way that a temperature or at elevated temperatures ge-20 Product containing up to 60% solids dries. The track is either finished after

Drying or during the last part of the drying stage itself at a temperature between about 99 and 400 ⁰ C for a time between about half an hour at the lower temperature and only 5 seconds baked or hardened at the upper temperature. The baking and curing conditions are set so that there is no deterioration or destruction of the fibers or the copolymer. The curing takes place preferably at a temperature between 127 and 163 ^° C. for a time between 2 and 10 minutes.

It is assumed that the polymer molecules are crosslinked during the curing process are implemented and that a state is reached in which the binder against washing and dry cleaning is very resistant.

The nonwovens obtained according to the invention are characterized by softness, flexibility, resistance to resistance Discoloration when exposed to UV light, and also to chlorinated hydrocarbon liquids, which are used for dry cleaning, and by resistance to Wash excellent. Because of the softness and flexibility and the good wearing properties are the nonwovens obtained according to the invention are suitable for items of clothing in which porosity, especially for Water vapor and a soft feel and feel are particularly advantageous when these Products can come into contact with the wearer's skin. The products are fairly dimensionally stable, have good elasticity and shape retention properties. The products can be used not only for garments but also for padding and padding and for moisture-absorbing objects, such as children's bibs and documents. They are also used as heat and sound insulating materials and as Filter media useful for both liquids and gases.

For some uses, and especially when a treatment with chlorine and resp. or ironing is not intended, the copolymer used according to the invention can be used together with a thermosetting resin condensate, e.g. B. an aminoplast or polyepoxy resin, be used. The amount of resin condensate incorporated into the binder can be up to 20 percent by weight of the copolymer, with the use of such a condensate a proportion of 3 to 10% is preferably used.

Aminoplast condensates that can be used are the low molecular weight or monomeric reaction products of formaldehyde with urea, thiourea, biuret or other homologues or derivatives thereof, such as Ν, Ν-ethylene urea, N ₅ N'-ethylene urea, Ν, Ν'-dimethylurea, N, N'- Diethylurea, N ₅ N '- dimethoxymethylurea, N ₅ N - dimethoxymethylurea, N ₅ N' - diethoxyethylurea, tetramethoxymethylurea and tetraethoxyethylurea should be mentioned. Similar reaction products of formaldehyde and triazines, such as melamine and Ν, Ν-dimethylmelamine, can also be used, as can e.g. B. modified with methyl or ethyl alcohol and heat-curing melamine-formaldehyde resin condensates, such as dimethoxymethylmonomethylolmelamine. The degree of condensation of these resin-forming aminoplast condensates should be such that they are still soluble or dispersible in water.

Heat curable epoxy condensates can be either soluble in water or self-dispersible in Be water. Water-soluble epoxy resins correspond to the compounds of the formula (I), (II) and (III):

H ₂ C CHCH ₂ O (Ch ₂ CH (OH) CH ₂ O) ₂ CH ₂ CH CH ₂

ο ο

where χ is a number with an average value from 1 to 3,

H ₂ C CHCH ₂ O (CH ₂ ) JzOCH ₂ CH CH ₂

(I)

(Π)

where y is a number with an average value from 2 to 4, and

H ₂ C CHCH ₂ O (C _ra H _2m O) ₂ CH ₂ CH CH ₂

(III)

in which m is an integer with a value of 2 to 4 epoxy group-containing condensates

and ζ a number with an average value of compounds of the above formula (III),

1 to 5 is. 60 in which y has an average value of 5 to 10,

Regarding water-insoluble, but self-dispersible, and also compounds of the formula (IV):

H ₂ C CHCH ₂ O (<Z> C (CH3) 20O) j, CH ₂ CH CH ₂

(IV)

in which Φ is a p-phenylene group and ρ is a number with an average value of 1 to 3.

example 1

1000 parts of an aqueous dispersion containing 45 percent by weight of an emulsion copolymer of 86% butyl acrylate, 10% vinyl acetate and 4% methacrylic acid amide are mixed with 105 parts by weight of a 10% strength solution of sodium hydroxide. The dispersion is ^{heated to 93 °} C. and left to stand at this temperature for 20 minutes, a pH of 9.7 being reached. 50% of the vinyl acetate units are converted into vinyl alcohol units. It is neutralized up to pH 3 with dilute hydrochloric acid. 100 parts of the copolymer dispersion obtained, which contain 35 parts of the copolymer, are then mixed with 0.5 part of oxalic acid. A carded web of viscose fibers of 2 denier is drawn through the polymer dispersion up to an absorption of 125% dispersion. After drying in air, the impregnated web is ^{treated at 127 °} C. for 5 minutes. The bonded web obtained is pliable, soft and withstands washing in an automatic washing machine. The product also withstands dry cleaning in a cleaning liquid consisting of 11.3 liters of carbon tetrachloride, 31 g of water and 4.5 g of the sodium salt of dicapryl sulfosuccinate.

Example 2

30th

The process described in Example 1 is repeated, except that an emulsion copolymer is used Made from 74% butyl acrylate, 20% vinyl acetate and 6% methacrylic acid amide and used half the Vinyl acetate units hydrolyzed so that 10 percent by weight Vinyl alcohol units are introduced. The product shows among those described in Example 1 Conditions good resistance to both washing and dry cleaning. Example 3

(a) The procedure described in Example 2 is repeated, only curing takes place in 5 minutes at 149 ° C. A carded sheet made of viscose silk and bleached cotton is used There is a ratio of 75:25. The liquor pick-up is 600% of the fiber weight, while the The weight ratio of fiber to binder in the finished product is 33:67.

(b) The procedure described in part (a) is repeated except that the aqueous dispersion contains the Copolymer additionally 3.5% dimethylol-Ν, Ν'-ethylene urea.

(c) The procedure described in part (a) is repeated except that the aqueous dispersion contains the Copolymer additionally 3% dimethoxymethylurea.

(d) The procedure described in part (a) is repeated except that the aqueous dispersion contains the Copolymer additionally 2.5% trimethylolmelamine.

(e) The process described in part (a) is repeated, except that the aqueous dispersion of the copolymer additionally contains 4% of a polyepoxide of the formula (I) in which χ = 4.

The nonwovens produced according to (b), (c), (d) and (e) are more resilient than that fleece produced by the method of part (a), they withstand a large number of washing and dry cleaning operations.

Example 4

The procedure described in Example 2 is repeated, except that air is deposited Sheets of the following fibers are used:

1. 100% regenerated cellulose (2.0 denier, 3.8 cm staple length), carded web weighing 62.2 g / 0.84 m ² ;

2. 55% polyamide fibers ("nylon 66") and 45% regenerated cellulose fibers, both 5 denier, 4,, 45 cm Stack length;

3. 100% cotton, carded web weighing 124.4 g / 0.84 m ² ;

4. 35% cotton and 65% polyethylene glycol terephthalate, carded web with a weight of 38 g / 0.84 m ² .

Example 5

The same results are obtained when the procedure described in Example 1 is repeated, however, the butyl acrylate in the copolymer is replaced by a corresponding proportion of 2-ethylhexyl acrylate or lauryl methacrylate is replaced.

Claims (5)

PATENT CLAIMS: 1. A process for the production of a soft nonwoven fabric from fibers in random layers using a binder containing a thermoplastic polymer, characterized in that the material is treated with 15 to 50 percent by weight binder, based on the total weight of binder and fibers, in the form of an aqueous dispersion The binder consists of a water-insoluble copolymer whose units consist of 4 to 6 percent by weight methacrylic acid amide units, 5 to 15 percent by weight vinyl alcohol units, 1 to 45 percent by weight vinyl acetate and 46 to 90 percent by weight of an ester of acrylic or methacrylic acid with 4 to 18 carbon atoms alkanol containing exist, and that the impregnated fiber mass with the binder is dried and heated to a temperature of 99-400 ⁰ C. 2. The method according to claim 1, characterized in that that the copolymer component of the binder is either a linear addition copolymer or a graft copolymer is. 3. The method according to claim 1, characterized in that that, in addition, the binder is a water-dispersible, heat-curing one Contains resin condensate which is either an aminoplast condensate or a polyepoxy resin, wherein the proportion of this binder component up to 20 percent by weight of the copolymer matters. 4. The method according to claim 3, characterized in that the aminoplast used 9 10 condensate is a low molecular weight or monomeric triazine or such a product that with Reaction product of formaldehyde has been modified with urine alcohol. substance, thiourea, biuret or other homo- 5. The method according to claim 3, characterized in that logen or derivatives of these compounds, which characterizes that the polyepoxy resin is one of the Reaction product of formaldehyde with a 5 formulas (I), (II), (III) or (IV) corresponds to: H ₂ C CHCH ₂ O (CH ₂ CH (OH) Ch ₂ O) ₃₁ CH ₂ CH CH ₂ (I) O O in which λ: is a number from 1 to 3, H ₂ C CHCH ₂ O (CH ₂ ) ^ OCH ₂ Ch CH ₂ (II) where y is a number from 2 to 10, H ₂ C CHCH ₂ O (C _ro H _2ro O) _z CH ₂ CH CH ₂ (III) in which m is a number from 2 to 4 and ζ is a number from 1 to 5 or H ₂ C CHCH ₂ O (0C (CH ₃ ) ₂ 0O) _i) CH ₂ CH CH ₂ (IV) in which Φ is a p-phenylene group and ρ is a number from 1 to 3. Considered publications: U.S. Patent No. 2,837,462; British Patent No. 774620; Rev. Produits Chim., 1961, pp. 492-502. 309 SSO / 399 5.63