DE2364091C3 - Flameproof, infusible fibers and processes for their manufacture - Google Patents

Description

The invention relates to flame-retardant or flame-retardant, infusible fibers, especially fibers that mainly consist of a melamine-aldehyde resin, and processes for their manufacture.

For certain purposes and in general to prevent the risk of fire and thus There is a need for general textile products such as garments, in particular Children's clothing, bedding, curtains, mats, carpets, etc., made of flame retardant or flame retardant To manufacture fibers.

In addition to having flame retardant properties, it is desirable that the textiles and fibers be thermal are infusible, show little thermal shrinkage and so little when heated Smoke or toxic gas form as possible as these undesirable properties pose a significant hazard of the user.

Virtually all well known fibers in common use are extremely flammable and therefore dangerous. Exceptions are special fibers such as inorganic fibers, carbon fibers and phenolic resin fibers. Even if a fiber is flame retardant, it is usually fusible or shrinkable Exposure to heat or, if heated, may generate large amounts of smoke and / or toxic gas to develop. Thus, because of these properties, even if the fiber is flame retardant, the material is not suitable for preventing the risk of fire and possible physical harm. With others

Words, it is considered in addition to the flame resistance Such is often absolutely necessary that the fiber also has the properties indicated above

The special fibers mentioned are, in spite of their flame resistance properties, not for general use Suitable for use in the textile industry Therefore, the inorganic fibers and the Carbon fibers, although they have desirable flame retardancy properties, generally

Fibers are flame-resistant and infusible and show an extremely low thermal effect when heated Shrink. As a result, the subject matter of the invention differs significantly from that in the total mentioned Japanese patent application. From US-PS 23 76 511 fibers are already with increased softening point and improved water resistance, made from a synthetic thermosetting material Resin, for example a phenolic

do not mean that formaldehyde resin or a urea mold are used in the manufacture of textile goods, Since they are subject to certain conditions, aldehyde resin, and a synthetic thermodie for such purposes there should be plastic resin, as well as a method for their Hermusses, Have disadvantages. In particular, let position known. In this very general relate these fibers because of their sufficient strength ten prior art can be found among other things and flexibility only poorly and weave 15 the indication that than other synthetic heat-hardening and also show good thermal conductivity, bare resins also melamine resins can be used a low hygroscopicity, a bad handle can. These melamine resins are different and poor dyeability. Furthermore, however, it is difficult of the products according to the invention Phenolic resin fibers to be spun and through that they, as in this prior art weave, since they have only a low strength, 20 is indicated (p. 1, right column, lines 2 to 4) d. H. Tear strengths of only 1 to 1. S g / denier condensation products from dicyandiamide and even though these fibers are formaldehyde because of their nature. The condensation products Flame resistance properties of increasing interest differ from dicyandiamide and formaldehyde to win. Furthermore, the phenolic resin fibers have each other structurally and in terms of their a characteristic yellow-brown color and are properties of the reports according to the invention, even after they were practically white bleached amine-aldehyde resins, what from the reference "Aminoplastics," C. P. Vale and W.G. K.Taylor, colors. Furthermore, these fibers can be very poor p. 58 and 59, it continues to exist in this respect to be stained. Such properties are different from those in this prior art Textile fibers, which are to be used in general, 30 mentioned solvents not readily for the absolutely inadequate, so that phenolic resin fibers are suitable in melamine-aldehyde resins according to the invention the textile industry have not found widespread use. If in this state of the art on p. 1 to have. indicated that the thermosetting resin and the

There is therefore a need for fibers that are substantially the same as thermoplastic resin In addition to the flame retardancy, the other large quantities should also be used, so this is the case have stocks that are used to manufacture in connection with p. 2, left column enable textile goods to be developed.

It has not yet been described in the literature
been that you can produce fibers that consist predominantly of melamine-aldehyde resins. Thermosetting resins preferred in this prior art are phenol-formaldehyde resins, be-no. 47-14771 relates to fibers made from polyvinyl alcohol and N-methylol melamine or methylated
Methylolmelamine are made. Since the in this
The amount of N-methylolamine 45 present in the mixture,
only 5 to 20% by weight>, based on the ge It is also known

see, in which it is stated that normally the thermosetting resin with respect to the thermoplastic Resin is used in small amounts. The after

or urea-formaldehyde resins, which have the aforementioned disadvantages of the characteristic yellow-brown coloring and the bad coloring

that melamine form

weight of the polyvinyl alcohols, aldehyde resins are often used as finishes for textiles Fiber can be used as polyvinyl alcohol fiber to designate or fabric. In this net, as it consists mainly of this material. In this case, only a small amount of the melamine continues to adhere These fibers are flammable and show resin on the surface of the fabrics that make up the fabric Fibers, so that there is a considerable difference between those with a melamine resin coated fibers and those according to the invention

Fibers is made up of melamine-aldehyde resins

thermal shrinkage as they melt at 300 ° C. These fibers are therefore not flame-retardant Fibers in the sense given above. In contrast, the minimum amount of in the

Fibers according to the invention contained melamine 55 are constructed.

Resin at least 150 ^e / o by weight, based on the The object of the invention is to produce weight of other polymers, such as polyvinyl flame-retardant fibers, which at the same time alcohol, which can also be present. The infusible, show a low thermal shrinkage in the mentioned Japanese patent application, when heated only a small amount, the process is essentially a smoke and toxic gas and yet a dry spinning process for the production of poly- high strength, a high whiteness, a good vinyl alcohol fiber. In addition, the fibers produced according to the known method of flexibility, good grip and good dyeing are readily available.

essentially the same properties as poly- the subject of the invention are therefore flame-retardant,

vinyl alcohol fibers as they, when exposed to a flame 65, are infusible fibers made from a hardened

come into contact, burn and completely remove melamine-aldehyde resin or an alkyl ether.

melt and, when heated, a considerable amount of thermal energy, a hardened condensation product

show mixed shrinkage. The melamine-aldehyde resin according to the invention and a cocon-

23 64

condensable compound and / or a hardened one physical mixture of melamine-aldehyde resin with a thermosetting or thermoplastic, fiber-forming polymer, and optionally customary fiber additives exist, the Melamine-aldehyde resin makes up at least 60% by weight of the fibers in all cases.

The invention also relates to a method for producing these fibers, characterized in that is that you get a solution of a melamine-aldehyde precondensate or the fiber raw material containing at least 60% by weight of this precondensate in spun in a known manner in a heated atmosphere and at the same time the solvent evaporates and the precondensate hardens

According to the invention it is particularly preferred that the melamine-aldehyde resin with a second polymer, such as polyvinyl alcohol, modified or mixed, creating a spinning solution with extremely good spinnability and fibers with extremely advantageous properties.

Particularly preferred fibers according to the invention are flame-resistant and infusible fibers with a Swelling capacity in water of less than 2.0, which can be obtained by hardening the spinning de ' Melamine-aldehyde precondensates obtained fibers.

Further embodiments, objects and advantages of the invention emerge from the following Description and examples.

According to one embodiment of the invention, the melamine fibers are essentially closed 100% by weight from the melamine-aldehyde resins described below. Of course, minor Levels of impurities in these resins can be found in the manufacture of these materials may have crept in. According to a further embodiment of the invention exist the fibers made from melamine-aldehyde resins, which condense with other fiber-forming polymers or mixed. However, it is required that the fibers of this embodiment at least 60% by weight, preferably 70% by weight, based on the total weight of the fibers, of the further contain melamine-aldehyde resins described below. Thus, there is a significant difference between the fibers of the invention and the Fibers that contain only small amounts of melamine-aldehyde resins or are coated with such resins are. so

In the method according to the invention, as already indicated above, initially by dissolving A spinning solution in a melamine-aldehyde condensate in a suitable solvent manufactured. The precondensates are thermal and soluble in water and organic solvents meltable low molecular weight resins which can be prepared using conventional procedures Reacting a melamine with an aldehyde preserves what is usually in solution in a usual Solvent and optionally takes place in the presence of catalysts. In this context, let to the publications by VaIe and Taylor ("Aminoplastics", 1964, p. 44) and Walker ("Formaldehyde", 1944, p. 218) pointed out. Alternatively, in the method according to the invention Commercially available melamine-aldehyde precondensates can also be used.

The conditions in the reaction of the melamine with the aldehyde with the formation of the precondensates mentioned are not particularly critical. In general, the reaction can be carried out at a temperature of 50 to 90 ° C for a period of 10 minutes to 3 hours. Preferably Keeping the pH of the reaction mixture in a range from 5 to 9, although one is the reaction Can also be carried out under neutral or weakly acidic conditions

The reaction can be carried out in the presence of a solvent for one or both of the reactants the particular solvent used is not critical and any material employed can be in which one or both reactants can be dissolved. That at the moment preferred solvent is water, with additional solvents such as organic solvents, can be used. Typical organic solvents are alcohols, acetone, dimethylformamide, Dimethyl sulfoxide, dimethylacetamide, phenols, mixtures thereof, etc.

Additionally, the reaction can be carried out in the presence of either an acidic or an alkaline catalyst be performed. Typical acidic catalysts are hydrochloric acid, sulfuric acid, amicic acid, Acetic acid, oxalic acid, etc., while representatives of alkaline catalysts are sodium hydroxide, Potassium hydroxide, sodium carbonate and sodium bicarbonate, etc. are.

The ratio of the reactants is also not particularly critical. If, for example, the reaction between 2,4,6-triamino-s-triazine (hereinafter referred to as "melamine") and formaldehyde is considered, it is possible to react 1 mole of melamine with up to 6 moles of formaldehyde, which is due to the presence of the 3 amino groups in the triazine compound is possible. By definition, the reaction product has a degree of hydroxymethylation of 6 when 1 mol of melamine is combined with 6 mol of formaldehyde. The hydroxymethyl-Iierungsgrad may 2. B. be determined by that one determines the difference of the added amount of formaldehyde to the reaction system and the amount of unreacted formaldehyde remaining after the reaction, and sets with de "amount of melamine in reference. The fibers according to the invention can be made from precondensates which have a degree of hydroxymethylation of 1.5 to 6.0. The degree of hydroxymethylation of the precondensates should preferably be taken into account with regard to the flame resistance and the mechanical properties of the fibers. Range from 2.0 to 6.0

The reaction conditions mentioned in the reaction of melamine with the aldehyde can vary from can be changed by the specialist as desired. This reaction is not new, so that one skilled in the art would recognize you can easily operate.

The reaction is preferably carried out in a solvent, for which purpose one is advantageous Water used. The precondensate formed during the reaction can be isolated in the form of a powder when the solution obtained as the reaction product is concentrated, cooled, with a precipitating agent added and dries. The powdery product can then in a solvent, such as water, are dissolved, so that the spinning used in the process according to the invention

solution received. Alternatively, the solution obtained as the reaction product can be used directly, if appropriate after a concentration or a dilution to the desired concentration, as a spinning solution be used. For the production of the spinning solution used in the process according to the invention both alternatives are possible. Another alternative is to use commercially available powdered ones or to use melamine-formaldehyde precondensates in the form of aqueous solutions.

An example of a method for producing the melamine-aldehyde precondensate is nevertheless stated: By reacting melamine with formaldehyde, one produces N-methylolmelamine (i.e. N-methylol-2,4,6-triamino-s-triazine). The reactions of other melamines with other aldehydes can be carried out in the same way. A reaction vessel is charged with 1 mol of melamine and 3 moles of formaldehyde (in the form of a 37 weight percent aqueous solution) and sets the pH the resulting mixture with alkali, such as sodium hydroxide, sodium carbonate or sodium bicarbonate, to a value from 8 to 9. The reaction then takes place by heating for 50 minutes to a temperature of 75 to 85 ° C. A precondensate of N-methylolamine is obtained with a Degree of hydroxymethylation of 2.7, which is in the form of an aqueous solution with a concentration of 56% by weight is present.

A wide variety of melamines and aldehydes can be used according to the invention. In general 2,4,6-triamino-s-triazine, N-substituted derivatives are used as the melamine component of the resin this compound, guanamine or substituted guanamines. As substituted derivatives of the above Triazines can be N-. N, N- or N, N, N-substituted Triazines, the substituents of which are not critical, use Find. Typical substituents are alkyl groups with 1 to 8 carbon atoms, allyl groups, aryl groups with 6 to 10 carbon atoms or halogen-substituted alkyl groups having 1 to 8 carbon atoms. Examples of such N-substituted triazine derivatives are N-butyl-2,4,6-triamino-s-triazine, N, N-dialryl-2,4,6-triamino-s-triazine, N-tert-octyl-2,4,6-triamino-s-triazine and N-halomethyl-2,4,6-triamino-s -triazine etc.

Examples of substituted guanamines are diguanamine, acetoguanamm, benzoguanamine , etc.

It is also within the scope of the invention to use mixtures of the melam compounds mentioned. The particular substituted derivative of triazine or gaanamine is not critical, provided that the compound chosen can be reacted with an aldehyde to form the precondensate used in the process of the invention.

With regard to the aldehyde used for the formation of the precondensate, there are also no particular restrictions, so that, according to the invention, any aldehyde can be used which can be converted into a precondensate with a dam that can be spun into a fiber. Typical aldehydes are (saturated and unsaturated) aliphatic aldehydes, cyclic aldehydes and aromatic aldehydes as well as substituted derivatives of these compounds. Typical aldehydes suitable according to the invention are formaldehyde, acrolein, methylal, glyoxal, acetaldehyde, polyoxymethylene, polyoxymethylene glycol, paraformaldehyde, etc. Examples of cyclic aldehydes are paraformaldehyde, dioxolane, trioxane and tetraoxane. Examples of aromatic aldehydes are benzaldehyde, 2,4,6-trimethylbenzaldehyde and 1,2-diformylbenzene. According to the invention, substituted derivatives of the aldehydes mentioned can also be used, typical substituents being hydroxyl groups, amino groups and halogen atoms. Examples of substituted aldehyde derivatives are therefore glycolaldehyde, aminoacetaldehyde and chloral. Mixtures of the aldehydes mentioned can also be used according to the invention.

The preferred reactants are 2,4,6-triamino-s-triazine and formaldehyde.

Roughly speaking, the precondensates used according to the invention are condensation products a melamine and an aldehyde which condenses to a low molecular weight compound that can be thermally fusible, soluble in water and organic solvents and has a degree of hydroxymethylation of 1.5 to 6.0.

The precondensate used to produce the spinning solution used according to the invention can can be made from the following materials:

1. the condensation product of a melamine and an aldehyde as indicated above;

2. the condensation product of said melamine-aldehyde condensation product with a compound condensable therewith, such as other aldehydes or substituted guanamines (such as benzoguanamine or acetoguanamine) or other compounds such as amines, Ureas, phenols, etc .;

3. the condensation product of the melamine-aldehyde condensation product with a natural or synthetic, fiber-forming polymer, wherein the condensation product can be formed in such a way that the condensation reaction between the melamine and the aldehyde is carried out in the presence of such another polymer. Polymers of this type are various (different from melamine resins) heat-treatable, thermoplastic polymers and mixtures thereof, the water-soluble, thermoplastic, fiber-forming polymers being preferred and polyvinyl alcohol being particularly preferred;

4. the alkyl ether of the melamine-aldehyde condensation product, which is obtained by reacting this melamine-aldehyde condensation product forms with, for example, alcohols, whereby alkylated methylamines. An example this is methylated methylol-2,4,6-triaminos-triazine, which is obtained by reacting N-Methyiolmelamin obtained with methanol in the presence of an acidic catalyst Various alcohols can be used to form these alkylated derivatives, wherein the monohydric primary alcohols, especially monohydric primary alcohols with 1 to 4 carbon atoms, such as methanol, are preferred. These alkylated derivatives are generally

9 * ίο

ETS- ⁿ A ^d H ^d _h ^Ur ? V ^he ^ ^estelIt ' ^that , ^{the solution depends} on its viscosity, although the used melamine-aldehyde condensation product (given solvent, the pH value of the solution, the

? „/, Rl ^{m G} , ^egenwart ^ T ^K _a Ä ^at0 .!?> ^At aging temperature as well as the type and the amount

? 0 hJÄ T ^oF t rf Ail IS ^{irend the existing} "Additive some influence

Reacts with the alcohol for 10 to 60 minutes; ₅ exercise. A good spinnable wedge is achieved

5. the mixtures of the melamine-aldehyde if the viscosity determined at 35 ° C. with a rotational viscometer with a rotational viscometer condensation product with fiber-forming na- (B-type) is in the range from 40 to natural or synthetic polymers. 3600 poise. When the Vorkondensatkonzen-Iypische are polymers thermosetting (of tialion in the spinning solution is less than 20 weight / ^«0 the melamine resins different) is polymers ■", it is difficult to obtain a viscosity of 40 poise and thermoplastic polymers, as well as micro what poor spinnability to the mixtures thereof. preferred are water-soluble, has a row and a stable spinning process impossible thermoplastic fiber-forming polymers, power. on the other hand, the Vorkondensatkonzenwobei polyvinyl alcohol on bevorzugtesten concentration of the spinning solution more than 85 Vo is be ^{smd 'and 1} S is the probability that the viscosity of the

6. the mixtures of the above products. Spinning solute higher than 3600 poise so it lies

Any one of the six above-mentioned materials üSTb ^ SSR ΐί ί * ΪΓ ^ Ta ^ ^ Tf, to prepare the spinning of the invention SS2 ■ '' viscosity

solution can be used so that ta MateSen * o 2500 pTe S ÜLT "! ™ n ² ° i ^

hereinafter referred to as “precondensates” - 800 to 500Poise 1V f I ""! Γ? Λ ^V ° ". %%. Γ ?. , ™, ^Poise ' ^he & l · ^where the viscosities

For those precondensates where DkΓ aboveSS ^ ' Y

Other materials in addition to the melamine-aldehyde viscosity range ^ T "κ T ™haben"? '^ T condensation product are present, the * ₅ meaning _U n _B nkh Ϊ £ ηΓ, ί? 7 ^V ° " ^{considerableIlC} , f ^e _ß ^r melamine-aldehyde condensation product comprises at least Sc Shu ?, u ^{'tlSCh> replaces them ahead} 8' ^that

Make up 6O «/ o of the pre-condensate. For example AusdS> ZlZS Λ * ""' Ti ™, · ^ ? " For materials 3 and 5, the melamine solution in Zft' uT ' ^d ^ ^{dlC S} - ^{P !? N} " aldehyde condensation product must be in an amount of can Ξ into fibers with? ^"on _p ^nehmbar 7 ^Geschwindl ßmindestens 60 weight""," based on the weight 30 are S * ^ ^{e 'genscha th} spun the entire precondensate be present. pre- Z ^ that ^ Liszt v, * T ^Μ <<Τ * ΐ ™ "] is preferably the melamine-aldehyde condensation des 'VersnLens Sin Γι ^S S ^nla f ^{en or during} product in the precondensai in an amount of the KoSrSiJn rfl ν υ' ^ ¹ ' ^S ° ^{mit may contain} ' ^ U at least 70 weight · /,. The lower of the eenann III S K ^v ° ^ ondensats not within the limit of 60 weight- /, results from this? the range mentioned and / or the viscosity of the lower Getalteo 'Γμ ££ Α? . "Sft SJf, ^ _1« «^ ^VOD condensate ^te the properties of KbH- a W ₁ Sm, i ^{g 'still be possible to b} g ^hch!? -

the fibers go bad. For example kö'nnen η ^ wennTm Χη / 'ΐ'^"SP" ™ ^1NC """8 ™ ^erha1 '

The special properties attributable to the melamine-aldehyde condensation the D Jn ™ ν 'measures, 40 areas £ JS ^. ° ^nCentratIOnS "" ^{and viscosity} such as flame resistance, also deteriorate SS Voric "S JT ⁰ "" ⁸ * -

Also check out the mechanical properties such as kömmlichm F ^ rfrfv "" ¹¹ "* ^{different fro} 'the strength and the elongation subside, be offset ^ ml'chen fiber additives. However,

Accordingly, any of the above mentioned advantages can be used. ^{8, Me 'am} i ⁿ - ^Ald ehyd-Kondenkondensate for the preparation according to the invention ^_45! da Sf !, f ^te ? ^{S 60 weighting-} ts ° / <>, based dope used used werdln As additives betrf ⁸ ^ * ^{1 oF Vorkond} ensats and the already mentioned above, can the Vorkonden- As AddiriuPit

sat after its production as a powder gain * n> λ 1 ^{to the} precondensate

or you can the resulting ReaktionsCg _e J SJiiW ** J "? *" * ^Μ '^ ^Mattierun ^ conducive necessary after appropriate up so FaseraddST? · ■'!, 8 ^{endwelche andCTe} "ü ^usual concentration and / or dilution, as a spin - observations1 ^ 'T ^{dtm Vork} ° ndensat acceptable solution to use, or you can be a commercially ER könnenTSh ™ m' ™ ^{are herkömmiiche} "additives hältiiches melamine-aldehyde condensation product de" macil "^?" ⁸ ^ ^ & F * - ^with use. no matter how the precondensate tSLTrf ¹ ^ *** ^ & sette additive neither receives, should the dope one! wSStaS 55 ^ SÜÜ ^ f? ¹ ^ ^{of the} "<""""* ■ concentration of 20 to 85 weight - · / ,, related Ξη erfnrrf.iL ^CU " ^meltability and the white on the weight of the spinning solution. The wSLS £ *? **? *» «* &« ***** (as the spinning solution must be spinnable and be stable what Ben Kden «, * ^ "? ^ ^{der erf} ^^^ S ^^ - the reason for the preferred concentration- AlsTmS «u ^ 'f

range from 20 to 85 Ve. _6o SninnliS-making means can be used to that

The preferred solvent for the spinning solution "reaktiw" _fl ^{ng a} _n ^{nOr8aniSChe 'or} g ^an5sch and so-called e is water, and in addition, other solution * - seSrT TWT ^ausrüstende materials to-

medium such as organic solvents, used advertising means''rinrfn f ¹⁰ ^ ^{8 "151} * ⁶ fireproofing the can. Typical organic solvents are phosphate ^ and °' ™™ ° ™» ™ * ^ as ammonium alcohols, acetone, Dimethylformamide, Dimethyl- « ₅ Caldumrhi ^ S ^." F ^ 'umbromid. Chlorides such as sulfoxide, dimethylacetamide, ⁰ ^ ^ phenol mixtures ma hSfil ZTW ^lt * ^Chlond <* <* AlummiumchtoricL these compounds, etc. sänre ai ^verbmdun gen. As sodium, boron

In general, the spinnability of the antimony STyU depends on? -i ^ l ^md "**« «» * «°

«Niimon and Zmn. Typical organic flame retardant

11 12

Making agents are for example Tricresylphos- merisats or the polymers in a solution phosphate, Cresyl diphenyl phosphate, triphenyl phosphate, condense medium with the aldehyde, whereby one chlorinated paraffins, chlorinated polyphenyls, etc. the spinning solution receives. Alternatively, you can Typical "reactive" flame retardants are condensation products obtained as a powder and used for z. B. phosphorus oxychloride, tetrakis (hydroxymethyl) - 5 Preparation of the spinning solution in a solvent Dissolve phosphonium chloride and tris (aziridinyl) phosphine (e.g. water). For the production of such pre-oxide etc. condensate, any procedure can be used.

As a fiber-forming polymer (as used above.

As stated above, the minimum sation product is either physically mixed or io amount of melamine-aldehyde condensation product can be condensed, depending on various tes in the precondensate 60% by weight fiber-forming, thermosetting polymers which differ from the total weight of the precondensate and that of the melamine resins) and any fiber additives. Use the forming, thermoplastic polymers. The particular selected polymer depends on the amount of polymer additives (ie fiber-forming desired properties of the fibers, the resins that are mixed or condensed with the melamine-aldehyde Konwobei one also polymer mixtures and dcnsation product) mixtures with the above-mentioned additives are improved, but on the other hand they can set a flame. Examples of suitable fiber-forming, strength properties of the fibers obtained in the thermoplastic polymer are thermoplastic »o decrease in which the amount of polymer polymer, such as water-soluble polymers, eg. B. Additive increases, since these other polymers are cellulose derivatives and polyvinyl alcohol, and in orga- are normally combustible. In other words, polymers which are soluble in solvents, e.g. , B. is therefore from the standpoint of flame-polyvinyl formal, polyvinyl, polyamide, poly- the maximum amount of polyvinyl chloride, polyethylene terephthalate and acrylic 25 merisat additives strength of view, 40 weight -%>, preferably nitrile. 30% by weight), based on the total weight of the

Any thermoplastic precondensate and additives can be used as the polymer. The minimum besches or use thermosetting polymer, the preferred amount for the polymer additive, insbefür the fiber formation is suitable and with the particular the water-soluble, thermoplastic, faamin-aldehyde condensation product is tolerable. 30 serum-forming polymers, is 0.02% by weight, Thermoplastic, water-soluble, fa- based on the total weight of precondensate are preferred ser-forming polymers. To achieve various and additives. With polymer additive quantities unneeded Properties of the fiber product are below the lower limit of 0.02% by weight different polymers are used. For example, it can be difficult but possible to combine spinnability certain polymer be known to improve the 35.

To improve the dyeability of the fibers, so that the preferred polymer additives are fiber

for this purpose it adds to the precondensate forming, water-soluble, thermoplastic polymer

However, the person skilled in the art is easily able to provide appropriate information. The preferred water-soluble polymers

Appropriate polymers for appropriate purposes are cellulose derivatives, polyacrylic acid, polyacrylic

to choose and deploy. 4 ° amide, polyvinyl alcohol, polyvinyl pyrrolidone and

If these polymers simply lead to the formation of polyethylene oxide. Typical cellulose derivatives are

Pre-condensate physically with the melamine-alde-carboxymethyl cellulose, methyl cellulose, ethyl cellulose

hyd condensation product can be mixed, lulose, etc. These polymers can be used as such

The spinning solution can be prepared as follows: One or can be used in the form of mixtures

The spinning solution can be prepared by mixing an aqueous 45 The most preferred polymer is polyvinyl alcohol

gen precondensate solution (or a solution in one of the reasons for incorporating the

other solvent) with a separately manufactured polymer additive, especially the what

th aqueous solution (or a solution in an insoluble, thermoplastic polymer, in di <

their solvent) of the resin (polymer) in fibers according to the invention is the improvement dei

horse riding. When the melamine-aldehyde condensation 50 flexibility and mechanical properties

product, either as a commercial product or in the strength and elongation that results

produced above, in the form of a powder for bend fibers. Due to the fact that MeI

If available, the powdered melamine-aldehyde resin can be made essentially hard resin

amine-aldehyde condensation product and the poly are and continue to have the flexibility of a complete

merisat separated in water (or another company consisting of a melamine-aldehyde resin

solvent) and the two solutions are inferior to that of other synthetic fibers

mix, or you can alternatively first that it is preferred that the bevels according to the invention

Polymer in water (or at least another solution to improve the fiber properties

medium) and then the melamine-Alde- a small amount (0.02 ⁰ Zo) of this water-soluble]

hyd condensation product with formation of the 60 thermoplastic fiber-forming polymers eni

Mix in the spinning solution. The special way to hold on. Melamine Aldehyde Resin Fibers That Do This

from which the spinning solution is obtained is not critical, water-soluble, fiber-forming, thermoplastic

In particular, what the physical mixtures of polymers in mixed form (in the case of a

ot get it. physical mixture) or in condensed

In addition, the polymers under Aosbil 65 form (if the polymer with the melamine Alde

formation of the precondensate is reacted with the melamine-aldehyde-hyd condensation product)

Condensation product to be condensed. In addition, they have a more favorable flexibility and improved

You can sniel the melamine in the presence of the poly-mechanical properties, which essentially dt

.1

23 64 09

13 14

NEN conventional synthetic fibers equivalent sat modified) precondensate which is likely are a consequence of the fact that the melamine in the

Another reason for incorporating the was-formaldehyde-containing polymer solution dissolvable, thermoplastic, fiber-forming polymer is and the polymer and melamine are present in a dissolved state prior to merizate in the prior to the reaction used according to the invention. The fact that the condensates and spinning solutions consist in ensuring that the resulting mixture is homogeneous is improved by the spinnability of the latter. One fact makes it clear that the solution becomes completely transparent during the spinning solution, which consists exclusively of a MeI reaction. The reason that amine-aldehyde resin contains resin can, in this case, be a homogeneous solution when the solution has a viscosity of 200 to 2500 io is not known with certainty. It is believed that, by extrusion into an atmosphere, they are spun into fibers as a reaction product at high temperature. falling solution a mixture of 1) the (with the spinnability of this solution is however for the polymer additive) modified precondensate, technical application not sufficient, even 2) the melamine-aldehyde condensation product if it has a viscosity within the specified 15 and 3 ) the polymer additive and that this range is because the spinning speed is quite low due to the action of the precondensate modified with the poly (ie 10 to 20 m per minute of the polymer additive) and it is difficult in certain cases That gene can be mixed, despite the fact that the spinning act at higher speeds to be melamine-aldehyde condensation product with the. On the other hand, a spinning solution shows that the polymer additive is not sufficiently compatible. water-soluble, thermoplastic, fiber-forming poly- Regardless of the mechanism, a homerizate is obtained in amounts which are within the above-specified spinning solution, if the precondensate range, is formed at a viscosity of in the presence of the polymer additive.
200 to 2500 poise an excellent spinning The preferred spinning solution with the best

availability, so that it is possible to produce such solutions at 25 spinnability is a spinning solution, the poly vim lalko speeds to fetch from 10 to 150 m per minute. the precondensate and either boric acid or spin. However, the fact is that it is possible to contain a borate. This spinning solution can under Aneine To spin fibers made entirely from a MeI twist of any process amine-aldehyde resin without the named polymer and can either be a mixture of the preconding additives Although it is preferred, the latter consists of polyvinyl alcohol and boric acid or one incorporate ren materials. Borate or one modified with polyvinyl alcohol

The spinnability of a spinning solution can, as has already been indicated above, contain precondensate containing boric acid or a borate, the latter embodiment being improved beforehand by adding the polymer. The latter material is provided e.g. B. dasal additive physically mixed in. A further improvement is that the melamine with three aldehydes can be spinnable in solution in the presence of polyvinyl alcohol and in that the precondensate is reacted in the presence of boric acid or the borate.
Polymer additive, especially in the presence of the In the former case, when using the mixture

Water-soluble, thermoplastic, fiber-forming polyvinyl alcohol with the precondensate are polymer additives, most preferably polyvinyl alcohol for producing the spinning solutions. For example, one can use a spinning method. For example, boric acid or a solution with excellent spinnability can be prepared by adding the borate to an aqueous solution and the precondensate by adding the melamine to a solution of the solution containing the polyvinyl alcohol. Polymer additives in formalin (ie an aqueous solution of the boric acid or the borate can be used as formaldehyde solution) or alternatively to an either an aqueous solution of the precondensation aqueous solution containing formaldehyde or an aqueous solution of the polyvinyl polymer adding additives and the mixture sol or alcohol to give two solutions woraui chen conditions subjecting that the Vorkonden- mixing the solutions obtained. Another; sat is formed. Thus, a Spinngeschwindig- method is to use an aqueous polyvinyl wedge of up to about 210 m per minute, 5 ° alcohol solution with an aqueous solution to ver when using a spinning solution that mixes in the boric acid or a borate and the pre Reacting a melamine with formaldehyde contained in condensate, the latter being produced in the presence of the polymer additives. A further reason for the preferred preparation of the aldehyde in an aqueous solution of boron acid of the precondensate in the presence of a polymer or a borate is used to produce a solution

The additive is as follows. It is currently accepted with a polyvinyl alcohol modified pre

The fact that the homogeneity of the spinning solution achieves a condensate leads to a better spinnability having an influence on the spinning properties (ie that, as with a physical mixture of the two, the spinnability increases with increasing homogeneity, which in this type of spinning solution increases). If one used the dope by simply 60 additive polyvinyl alcohol has preferential physical mixing of the Vorpblymerisats with, a degree of polymerization 500-320 the polymer additive manufacturing, it is not completely in in it and a saponification degree of 75 to 100 MOI ⁰ / many cases The amount of polyvinyl alcohol in the mixture or an indication that the mixture is not completely homogeneous with preconditioner modified with polyvinyl alcohol is transparent. If one the other hand the spinning satellite 65 is preferably in a range of 5 b solution by preparing the precondensate in Gc 40 weight ⁰ / ", based on the total weight of the polymer ve prepares penwart additive, obtained precondensate and polyvinyl alcohol, to a homogeneous solution of the (with the polymeric The boric acid (H ₃ BO ₃ ) is preferably in cn *

15 " u

Yon amount from 0.2 to 20 weight ⁰ / ", based on the well these undesirable effects at pH values

Weight of the polyvinyl alcohol to which the spinning solution can occur that is outside this range

added, while the borate is preferably in, it is not absolutely necessary that the

Quantities νφη 0.02 to 10% by weight, based on the spinning solution, a pH value within this range

d & s weight of polyvinyl alcohol. 5 ches, although this is preferred.

The borates used according to the invention can Furthermore, the spinning solution after the manufacture

subject to customary treatments using the following general formula,

normally used in spinning conventional syn-

M ₁ ByO ₂ -MH ₂ O thüscher fibers can be used. For example!

ίο the spinning solution can be filtered and defoamed

in which M is an alkali metal atom, etc. Those skilled in the art are familiar with these conventional measures of an alkaline earth metal atom or the ammonium ion and their implementation.
B boron, Q oxygen, x, y and ζ a positive whole The next step of the VerZahl according to the invention and η 0 or an integer. One step after the production of the spinning solution and typical borate that can be used according to the invention, if necessary whose aging is of course that can be, is borax (ie Na ₂ B ₄ O ₇ · 10H ₂ O). Spinning the solution into fibers. So far have been

The most preferred, the precondensate, "the poly-fibers either by the melt spinning process, wet vinyl alcohol and boric acid or a borate-containing spinning process or dry spinning process can produce spinning solution according to the invention by Ex. In the first process, melt spinning or extrusion through a nozzle into a 20 process, a molten polymer to high temperature atmosphere with Spinnge- fibers is extruded, c ^'; s schwindigkeitcn then solidified by cooling to 500 m to be encrypted per minute In the wet spinning process will be Lösunsponnen This spinning solutions have further gen.. Polymers or polymer derivatives have excellent stability and good resistance - precipitated by spinning in a precipitation bath or rain sediment against gel formation or strong viscosity, which forms the fibers. Finally, wind changes. A typical solution of this type in the dry spinning process is a poly It is neither a gel, nor is it subject to strong viscous solution extruded or spun, whereupon the soldering changes if it is evaporated at 30 C during time solvent to dry the fibers for more than 10 hours. To solidify inside and the polymer,
The spinning solution is special, if it has been treated with Borax 30 process for the production of fibers from phenol, even after 80 hours (e.g. with 30 resins (which are of course thermosetting) are stable up to 70 C). Accordingly, such spinning-published Japanese patent application nos. Solutions containing boric acid can be stored or aged at temperatures 15,727/1966 and 6,596/1972 and in the "Textile from 30 to 50 C," Research Journal, Volume 28 , P. 473, described, rend borax-containing solutions at temperatures 35. In these processes, however, a conventional 30 to 70 C can be stored and sta- melt spinning process used, since the novolak remain bil. (a precursor to phenolic resins) heat fusible

With the exception of the borax containing spinning loam. and after the formation of the fibers a churning, the spinning solutions according to the invention should processing reaction is carried out. Although phenol is preferred at temperatures below 40 C resin fibers by dry spinning or wet aging or be stored. This is because the spinning process can be produced the precondensate at temperatures above 40 C always causes hardening after the fibers have formed, react further and its molecular weight by In the cited literature it is indicated that Crosslinking due to the formation of methylene the melt spinning process and the hardening of the same bonds can increase. When this happens, the> 5 tends to be able to be carried out in a timely manner, but this is the case when Spinning solution for gel formation, whereby the spinning melts the resin because of the above availability is reduced. Therefore, the melting point of the resin should be quite general mine the dope before spinning does not result in hardening of the resin melt, wocinc Temperature are heated, which is a further uncondensation due to further spinning after a short time of the precondensate with the formation of 50 becomes possible.

Compounds with a higher molecular weight to although the preconsequence used according to the invention could have. Furthermore, it is preferred that the densate also be used at temperatures above 150.degree Spinning solution after its production is in a molten state at Tempcratu-, perseverance occurs to be stored below 40 C until the viscosity of the precondensate reaches that of the infusible 40 to 3600 poise, preferably 200 to 2500 poise, 55 crosslinked product at such temperatures even more preferably 800 to 1500 Poisc (at 35 C with also quickly, whereby the polymer inside one cm Rotation viscometer type B measured) hardens or gels within a short time. As a result is enough if the viscosity is not unmiltelba. after it is not easy to use the fiberin according to the invention the production of the product within this range by means of a melt spinning process, obrcichc located. However, this precaution is only possible if certain precautionary measures are taken the preferred embodiment matters. taking is possible.

Weilerhin has the inventive spinning lo- It has therefore been shown that melamine-aldehyde

Solution preferably has a pH value of 5 to 9, so fibers from such precondensates do not pass

that the pH of the spinning solution can, if necessary, be established by known spinning processes,

should be adjusted to this area. At 65 which is the main reason that the crfind-

pH values below 5 or above 9 indicate that the fibers in question have not yet become known,

fmchmiisgemälic spinning solution has a tendency to gel- An essential feature of the invention is therefore the

hikluno and a worse Vcrspinnbarkcit. Whether to provide a suitable spinning process for

17th

Production of the fibers of the invention according to
that the dry spinning of the spinning solution takes place at the same time as the hardening of the precondensate

23 76511 described procedure «expires. Although given ter bottom factors According to the method of the invention analogous to manufacturing spinning temperature can subsequently hold _it extends conventional drying method since the se conducive or not necessary n In other the precondensate spin into a solution containing i "words that Hartungsrcaktion simultaneously with An atmosphere kept at high temperature exudes spinning, if the spinning temperature is high (to remove the solvent) enough is cherished Formation of the fibers conditions those that the material is dried during, but also at the same time a hardening i _{5 of} a necessary or sufficient time is carried out on a reaction by which the precondensate is heated to the conversion of the low molecular weight (by further K on-soluble and meltable melamine-aldehyde predensation reactions) to form a crosslinked polymer condensate in which the insoluble and infusible melamine-aldehyde resin in the form of fibers is cured three-dimensionally crosslinked melamine-aldehyde poly. The hardness reaction changes in the 20 merisat is sufficient. Depending on the particular melamines and aldehydes that are used in the reaction, the meltable and soluble pre-condensates and in the low molecular weight densates, the one three-dimensional sate vary the temperature and the curing time crosslinked structure, which is essentially a 35 corresponding. The person skilled in the art can, however, with mini-consequence of the crosslinking due to the formation of painful effort, the necessary conditions for methylene bonds. Determine achievement of the conversion mentioned.

If the spinning loam used according to the invention, in particular, sufficient hardening can be achieved

Solution merely by evaporating water to be determined by the following procedure Da Fibers is dried (as it is borrowed from a conventional 30 that makes up the fibers according to the invention Dry spinning process is the case), hardened melamine-aldehyde resin does not contain a linear polymer As the product is a fibrous solid from a merisate, it is impossible to determine its molecular weight Low molecular weight melamine resin that determine. The extent to which a three-dimensional poor strength and poor flexibility- sionally crosslinked, infusible and insoluble possesses speed, so that the winding of the fibers very 35 polymer is formed, but can through the becomes difficult or impossible. Therefore, the Her degree is that which occurred during the curing reaction Position of the fibers according to the invention can be expressed by a crosslinking, which by the swelling dry spinning process not preferred. capacity of the polymer is determined in particular

The precondensate is converted into a polymer with a low swelling conversion, a polymer with a high molecular weight 40 like a strongly three-dimensionally cross-linked structure and a colorless, transparent, flame door, while a polymer with a high swell resistance and infusible melamine aldehyde Resin fibers (converted to a suitable solvent. Similar melamine-aldehyde props) no excessive formation of a three-dimensional condensate are already known and in particular have a sional network and used according to the invention as molding compounds, adhesives and lacquers 45 can be described as insufficiently cured, The swelling capacity is found to be suitable as the ratio W ₁ ¹ W _{0 s or paper.} Because of the definition, where W is the weight of the fibers after the difficulty in providing a spinning process, immersion of the dry fibers for a period of time, however, no fibers have been produced so far, the correct length of time in a solvent and W ₀ consisting predominantly of such melamine resins. 50 weight of the same, but absolutely dry Fa-This problem is now according to the invention by ser mean. The swelling capacity increases with the said method being solved. mender crosslinking reaction, the minimum

If melamine and the aldehyde are equivalent to 1. A non-crosslinked polymer has an unlimited swelling capacity with an alkaline catalyst or without a catalyst, since the catalyst converts, the reaction product obtained is a polymer which is dissolved in the solvent.
N-alkylolmelamine with low molecular weight The sufficiently hardened, according to the invention one

(ie the precondensate). If an acidic catalyst is used for the reacted resins which have a swelling capacity of the cation, acids of less than 2.0 are formed in water, preferably the same N-alkylolmelamine, which, however, quickly becomes less than 1.5. Water is a solvent for alkylene bonds between neighboring molecules, the melamine-aldehyde precondensate. That forms in the oil. The initially formed precondensate scope of the invention process used to solidify upon heating by a condensation provision of this swelling power is as follows, tion reaction to an insoluble and infusible is dipped a dry fiber by the weight If ₀ cash, three-dimensionally crosslinked polymer which during 16 hours in water with a temperature according to the invention as melamine-aldehyde resin at 20 ° C and then dewatered while drawing and from which the fibers are produced for 5 minutes in a zen operated at 3000 rpm. This is the "hardening" reaction referred to above for trifuge at a centrifuge acceleration of FIG. 1 and that is used to produce the 1000 g. The resulting weight of the fa-

19 * 20

scr is denoted by W , while the ratio fertilize or the fiber-forming yon WZW ₀ mentioned under 3) stands for the swelling capacity that is condensed according to the invention, e.g. B. be thereby produced according to less than 2.0, preferably less than that the melamine and the aldehyde must be 1.5. If the swelling capacity reaches a value in the presence of the corresponding compound or of more than 2.0, the fiber has not converted enough of the fiber-forming polymer,
cured, which has the consequence that their tensile strength. If the melamine-aldehyde condensation pro-

and flexibility are too poor to simply physically duct a fiber with the fiber-forming poden to give the desired properties. lymerisat or mixtures thereof is mixed,

Accordingly, any suitable technique can be used to practice the present invention The products are completely or predominantly (i.e. to a minority. For example, one can gesture to the products 60% by weight) from a melamine-aldehyde separates dissolve in a solvent and the obtained resin Mix a few solutions with a swelling power in water.

less than 2.0. As stated above, the minimum,

one of the following materials or mixtures contained in the fibers according to the invention of which consist: 15 of melamine-aldehyde condensation product 60

% by weight, preferably at least 70% by weight,

1) at least 10% from a melamine based on the total weight of the fibers. Eriin-aldehyde condensation product; according to this, it is preferred that the fibers

2) at least 60% by weight (based on at least a certain amount of other fiber-forming buttocks weight the fiber) from a melamine-aldehyde ao contain lymerisate to give the fibers better self-condensation product, to lend that to one with it. The most preferred fiber forming densibles Compound is condensed, the polymers are the water described above Flame resistance properties and the soluble, thermoplastic polymers, whereby th fiber properties of these polymers according to the invention preferably in minimal men fibers not affected. Examples of compounds of 0.02% by weight based on weight Bonds of this kind are aldehydes (like acet- the fibers, contained in the fibers, being the aldehyde, acrolein, benzaldehyde or 2,4,6-tri maximum amount 40% by weight, more preferably 30 methylbenzaldehyde), substituted guanamines by weight, based on the weight of the fibers. B. benzoguanamine, acetoguanamine, etc.) carries. One of the reasons for incorporating such and other compounds such as phenol, cresol, water-soluble, thermoplastic polymers in the Urea, methylamine and ethylene diamine; fibers according to the invention (whether it is now

3) the condensation product or physical mixing with the melamine-aldehyde concave Mixture of at least 60 condensation products or by condensation in weight% (based on the weight of the con- this material takes place), is the, the flexibility and densation product or mixture) of the mechanical properties, such as strength Melamine-aldehyde condensation product with and the elongation to verbesanderen the fibers obtained fiber-forming natural or synthetic fibers. Melamine-aldehyde resin fibers that have these aesthetic properties Polymers. These »other polymer-soluble, fiber-forming, thermoplastic polymers« are thermosetting and thermoplastic merizates (of which polyvinyl alcohol is preferred) see polymers, which contain water-soluble, thermal 40 (in the case of a physical mixture) thermoplastic polymers are preferred. Poly or (in the case of the reaction of the polymer with vinyl alcohol is the preferred material and the melamine-aldehyde condensation product) will be incorporated Contained in amounts of 5 to 40% by weight, condensed, have improved flexural properties based on the weight of the fiber used. goodness and better mechanical properties that Examples of suitable fiber-forming thermosetting materials essentially those of conventional synthetic ones Bare resins are synthetic polymers, like fibers are equivalent.

Urea-formaldehyde resins, phenol form The fibers of the invention can be made from the

aldehyde resins and epoxy resins. Examples of melamine-aldehyde precondensates mentioned such as suitable fiber-forming thermoplastic resins are prepared as follows. Essentially that is are water-soluble polymers, e.g. B. Cellulose 50 process, as already mentioned, therein, from the fore derivatives and polyvinyl alcohol and to produce a spinning solution in organic condensate, the little spinning Solvent-soluble polymers, solution to be converted into fiber form and then z. B. Polyvinvlformal, Polyvinylbutylal, Poly- or at the same time the precondensate to the cross-linked, amide, polyvinyl chloride, polyethylene terephthalate thermally infusible and insoluble polymer and polyacrylonitrile. 55 seeds to harden, from which the invention

Fibers exist.

The preferred water-soluble, thermoplastic The spinning solution can be produced in any way

rule polymers are any polymers are made, whereby the used Verdieser Kinds that form fibers and are not critical with melamine driving. Thus, for. B. if that Aldehyde condensation product are compatible. At- 60 precondensate * completely from a melamine game for this purpose are cellulose derivatives (e.g. carboxy-aldehyde condensation product, which consists of spinning methyl cellulose, methyl cellulose, ethyl cellulose, etc.), solution can be prepared by using a MeI polyacrylic acid, Polyacrylamide, polyvinyl alcohol (the amine and an aldehyde in a solvent such as is most preferred), polyvinylpyrrolidone, poly-water, dissolves and reacts. The solution obtained can ethylene oxide etc. 65 used as it is as a spinning solution,

The fiber material according to the invention can, if necessary, have a corresponding concentration the melamine-aldehyde condensation product, adjustments are made. Alternatively, you can the compound-melamine-aldehyde condensation product mentioned with the above and under 2) thereby as

Powder win that you can be wound up as reaction products. This is a consequence resulting solution concentrated, cools, with the presence of polyvinyl alcohol in the fibers Precipitating agents added and sern for recovery, despite the fact that the hardening is insufficient of the powder dries The powder kai λ is then in one and to a swelling capacity in water of 2.0 suitable solvent such as water, 5 to 3.0 leads. Preferably and desirably whereby the spinning solution is obtained. Alternatively, the fibers can be further hardened by heating one commercially available, in powder form or in (what by treating the fibers with heated whale form Melamines present in aqueous solutions or in an atmosphere with a high temperature eraldehyde precondensates deploy. follows), so that fibers with a quenching capacity

When the melamine-aldehyde condensation proio in water is less than 2.0. The temperature duct with another condensable connection and the time required for this additional thermal insulation or with the other fiber-forming polymer treatment required depend on the source is condensed, this compound or by virtue of the starting material in water and the the resin is removed during the reaction of the melamine with the desired quenching capacity in water. The Fachdem Aldehyde be present. However, as the reaction pro 15 can easily be the temperature and the According to the invention, the resulting solution can select times which can be used to achieve a swelling can be used as a spinning solution, with liking in water of less than 2.0 necessary if necessary, any adjustments to the concentration are possible.

solutions carries out, or you can the reaction The dry reaction spinning according to the invention

Isolate the product in the form of a powder and then proceed as follows: The spinning

When the solution is in a suitable solvent, such as water, it is passed through a nozzle into a high temperature

solve in order to thereby maintain the temperature maintained atmosphere (air or an inert

To prepare dope. Atmosphere, such as nitrogen), whereupon the in

Regardless of how the fibers formed in this way according to the invention are produced on a reel or turned spinning solution, it is preferred that a bobbin be wound up. The Spinngeschwindie dope a precondensate concentration speed can dig of minimum values of approximately from 20 to 85 weight ⁰ / ", based on the weight of 10 to 20 m per minute (if the fibers fully stand spinning solution comprises. The term" precon- consist of the melamine-aldehyde resin) up to densat «stands for a condensation product, which at full speeds in the range of about 500 m per constantly from a melamine and an aldehyde - 30 minutes (if the fibers are a certain amount of poly-built, the condensation product of melamine vinyl alcohol contain) extend. The diameter of the aldehyde condensation product with the nozzle holes therewith can be about 0.05 to 1.0 mm, preferably condensable compounds, the mixture being 0.10 to 0.30 mm. The temperature of the fiber-forming polymers with the melamine atmosphere, into which the spinning solution is pressed or the aldehyde condensation product and the condensation product are extruded, can be 170 to 320.degree. A tion product of the melamine-aldehyde condensation temperature above about 170 C is required as a product with the fiber-forming polymers. the removal of that contained in the spinning solution

The spinning solution must be spinnable and stable solvent and the hardening reaction within

and for this reason preferably has to be carried out in a short time so that one

Concentration from 20 to 85%. 4 = contains hardened fibers, whereby the fact

If the spinning containing the precondensate is borne in such a way that in the case of molding processes under solution, hard ice is usually dried simply by evaporating the solvent. Using melamine resins, a fiber is formed from a processing temperature of 135 to 170 ° C. Low molecular weight melamine resin is used. A temperature above 320 C is and that the fiber obtained is soluble in water and a 45 is desirable, since the melamine resin and the others have unlimited swelling power. If, on the other hand, any polymers that may be present, the solvent can be damaged when the high temperatures in question are used,
according to the dry reaction spinning process The actual selected temperature depends on the vaporized and at the same time the curing reaction of many factors, such as the spinning speed, is carried out, one obtains fibers that are in water 50 the resin forming the fibers (ie whether the resin is insoluble and a quenching capacity in water of only a melamine-aldehyde resin or additionally less than 2.0. Furthermore, the extent to which a water-soluble, thermoplastic polymer, the extent to which the hardening reaction contains during the spinning, such as polyvinyl alcohol, takes place takes place , the swelling capacity in water, the swelling capacity in water etc. For the fibers that decrease in the direction of the minimum value of 1.0. According to the invention, however, it is only necessary to stand, to carry out the curing reaction at spinning speeds of 10 to so far that the 20 m per minute a temperature in the range of the cohesiveness of the fiber is less than 2, 0. Preferably 170 to 280 ° C. Similarly, it can be less than 1.5, since above this the temperature that is used for fibers, the fibers are not easily 60 that in addition to the melamine aldehyde Resin other can be wound up because they are insufficiently made of polymers, such as polyvinyl alcohol, are cured and have a low tensile strength and spinning speeds that are up to 500 in per minute poor flexibility., Extend from 190 to 320 ° C .

An exception is the embodiment, according to It is not necessary, according to the invention

the fibers produced in the spinning solutions polyvinyl alcohol and / or according to the method in the heat

Contain boric acid or a borate. To draw or stretch these fibers. However, the

can have a swelling capacity in water of 2.0 to 3.0 fibers, which are 5 to 40% by weight of a water-soluble

showcn and yet without the mentioned problems, thermoplastic, fiber-forming polymer

/ S

sats, such as polyvinyl alcohol, and containing a swelling property in water having in the range of 1.5 to 3.0, gewünsclitenfalls in the heat at temperatures above 100 ° C, preferably at 100 to 200 ^"!, C are stretched. The stretching or drawing can take place by reacting the fibers under tension with a hot roller or plate which is heated to said temperature, brought into contact or the fibers under tension through a heated atmosphere to the fibers at least 10 ¹ O its length to stretching, ie to achieve a stretching ratio of at least 1.1. The heat-stretched fiber is then wound onto the bobbin or the reel. At a temperature below 100 ° C., it is difficult to stretch the fiber by more than 10 ° .n its length so that this temperature must be at least 100 ° C., since stretching by this percentage is preferred and by at least ^ O "η is more preferred. Furthermore, if the fiber is drawn by less than 10 ° ο, a substantial increase in the strength of the fiber obtained cannot be achieved, and since this improvement in strength is the main purpose of the hot drawing, the fiber should be drawn by at least 10 ° ο Fiber cured to achieve the desired swelling capacity in water. If the swelling capacity in water is below 1.5, it is not possible with any of the fibers according to the invention to achieve a heat draw of at least 10% the hardened resin fibers has formed a three-dimensionally crosslinked network which is heat-stable, so that these fibers cannot be easily drawn by heating, which is the case with conventional linear polymer fibers which can be easily drawn in heat which are insufficiently hardened and which have a swelling capacity in water of more than 3.0, are not stretched at temperatures below 100 ° C. due to their lack of elasticity. Furthermore, such fibers (whose swelling capacity in water is above 3.0) cannot be drawn even at temperatures above 150.degree. C., since they tend to melt and lose their fiber shape, so that the fibers are drawn at temperatures between 100 and 150.degree but the drawn fibers show no increase in toughness.

Therefore, the fibers according to the invention, especially those which contain the water-soluble, thermoplastic, fiber-forming polymer (they 5 to 40 ° o polyvinyl alcohol) and which have a swelling capacity in water of 1.5 to 3.0, at temperatures above 100 C with a Stretching ratio of more than 10 ° Ό are stretched. In fact, such fibers can be up to about 200 ° ^; o (ie a draw ratio of 3) are drawn. Of course, the fibers must then be hardened sufficiently to bring the swelling capacity in water to below 2.0, preferably below 1.5.

The tensile strength of the fibers (which is generally increased by stretching) depends on the strength in water, the stretching temperature and the stretching ratio, as well as the type and amount of polymer additives incorporated into the fibers. The tensile strength of the drawn fibers is normally in the range of 1.7 to 5.0 g denier and is 0.1 to 1.5 g / denier greater than that of the undrawn fibers.

The fibers produced by the process according to the invention have the following properties. First, these fibers of the invention have excellent flame resistance, so that, even when they are brought into contact with a flame, they do not start to burn, only glow slightly and slowly. Will the flame

ίο removed, the glow stops almost immediately. Second, very little smoke is generated during this glow. Third are those Fibers are thermally infusible and show no significant shrinkage when heated.

Furthermore, the fibers of the invention have the properties required for general use are necessary. In particular, it is very easy to spin and weave these fibers, with you get products that have a good grip.

since the fibers have a tenacity of 1.6 to 5.0 g / denier and sufficient flexibility. Furthermore, they show excellent transparency and a good degree of whiteness as well as excellent colorability. In particular, the dye ^{absorption is practically 100 η} Ό if the fibers are immersed in an acid dye fiot at a temperature of 98 C. Furthermore, the fibers according to the invention have excellent coloring properties, the colored fibers showing high light resistance and good light fastness, the latter being classified in the fourth to sixth category according to JIS method L 0843-71. The fibers further have at 20 ° C and a relative humidity of 65 ° 0 excellent hygroscopicity 4-11 ⁰ O, equivalent to that of cellulose fibers. In addition, the fibers according to the invention show a low thermal conductivity and an adequate chemical resistance, with the exception of highly concentrated acids at high temperature. Finally, the properties mentioned are only slightly impaired during washing and dry cleaning.

The strength of the fibers according to the invention depends of course on the dimensions of the spinneret used, the nozzle usually having holes with a diameter of 0.05 to 1.0 mm, preferably 0.10 to 0.30 mm. In general, the fibers of the invention have a linear density of 0.5 to 1000 denier, although the strength of the fibers of the invention is not critical and the various fiber strengths depend on the intended end use.

In addition to the swelling capacity ii mentioned, water, which, as already stated, is below 2.0 is the birefringence (here with ".1" "from abbreviated) less than 0.02. In general mine corresponds to the .1n value of a polymer fiber to the extent of the orientation of the polymer forming the fiber, and it can be quite generally be noted that with increasing Reckver ratio (during the production of the fiber) 1 η values and the toughness of the fiber increase. This is because the higher the stretching ratio, the greater the orientation in general. In In contrast to these facts show the invention appropriate fibers, although the I n value is low and is below 0.02, a toughness of 1.6 bi 5.0 ρ denier and a sufficient flexible wedge

25 I ^y 26

Furthermore, the fibers according to the invention have knitted fabrics and, of course, nonwovens, are used excellent flame resistance properties and Furthermore, the fibers of the invention can be used as are thermally infusible. Those according to the invention or in the form of mixtures with others Fibers are used in particular previously known fibers with natural or synthetic fibers With regard to the latter property, consider what will be, what is common and within the scope of knowledge due to the degree of shrinkage of the fiber is within the range of the expert.

high temperature. The following examples are intended to further the invention

degree is the observed value of the shrinkage, explain without restricting it. The expression “melamine” given in expressed as a percentage, based on the original examples, stands for a fiber sample with a length of 10, unless otherwise stated, for 20 cm, which is exposed for 10 minutes with an air 2.4 , 6-triamino-s-triazine. atmosphere with a temperature of 300 ¹ C in.

Was brought into contact. It was found that, Example 1

although practically all organic synthetic fa- To 973 g formalin with a formaldehyde concentration

Sern completely decomposed at 300 ° C (ie carbonitration of 37 ⁰ O (ie 12 mol formaldehyde) there is) or a shrinkage of more than 189 g (1.5 mol) melamine and stir shows the Mi-50 ⁰ Zo , the melamine mixture according to the invention for 15 minutes at 85 C. The reachyd resin fibers a shrinkage of less than ionic mixture will then show under reduced pressure 10%, which is due to their superior infusibility with stirring at 60 ° C. for 3 hours indicates unity. In contrast to most of the organic fibers, the N-methylolmelamine precondensate according to the invention is obtained in 920 g of an aqueous solution of a synthetic fiber retained. The hygienic fibers, apart from their superior degree of droxymethylation of N-methylolmelamine be-infusibility, their original fiber state is 5.9. The concentration of this product in which the (through which they are not inflamed) in when brought into contact with fire advertising solution amounts from 49 weight 0. ⁰ and decompose 35 The solution is kept at 25 ° C, until they do not settle into carbon and form a good spinnability when it is produced, which then only heats very small amounts of smoke, and it is theirs if the strength predominantly retained at 35 ° C. with a rotational viscosity. certain meter of the type B viscosity of a value Due to these superior properties are achieved of 260 poise. At this point, the fibers according to the invention, in addition to the fact that the solution through a nozzle with holes with a diameter of 0.2 mm can be held in a nitrogen gas at 250 ° C. as excellent flame-retardant fibers, is a considerable enrichment - Pressed in atmosphere. The rotten technique represents. Spun fibers are simultaneously produced in this way.

Besides the fact that the invention dries and thermally cured and then Fibers wound up as flame-resistant fibers for the production of flame-retardant 35, whereby one fiber with a titer Solid textiles can be used, can of 12 denier and a swelling capacity? in water the fibers according to the invention generally also obtained from 1.26

can be used for other purposes, as they have a high degree of whiteness and good dyeability, since they are made of melamine-formaldehyde resin and have a good fit. The whiteness of the fibers 40 according to the invention is colorless and transparent. The tensile strength and that is above 0.7 and the elongation is 2.8 g denier or 14% by the following formula. The fiber of Judd defined: W = I- AE _SM prs _BM, burning in the when it is applied with a flame in contact ge-J E _SM the difference between the color of the fiber, not but smoulders slowly and and Color of the standard whiteness of Magne- slightly. The glow stops immediately after the sium oxide, ΔΕ _ΒΜ the color difference between the 45 distance from the flame. By heating, a fiber sample and a black body (the fiber of which does not melt. In addition, the specific reflectance shows 0) and W make the value of the fiber extremely small in shrinkage (i.e., a degree of whiteness ° / ₀ when heated in air to is essentially the same as that of 23O ^c C). The dyeability that a dye-absorbent fiber, which ^{corresponds to conventional linear polymerisation of 100 0} Z ₀ , if one is made of an acidic seed. Dye used at 98 ° C is just like that

Although the tear strength properties of the dyeing are excellent. The fibers produced according to the JIS regulation phenolic resins (the lightfastness of the dyed resins according to the invention, which is also heat-curable fibers, which is determined by L 0843-71, corresponds to the fifth category, the hygro resins) are good, have the phenolic resin poly- 55 scopicity at 20 C and one relative humidity merisate a characteristic light brown color. of 65 «0 is 8.6 · / <., which is sufficient for fibers, i.e. the dyeability of phenolic resins should also be used for items of clothing. The extremely poor, and the colored phenolic resin fibers water resistance is excellent as show the Fasei a dull appearance, which is a result of not substantially shrink when it is immersed in Wassei bad Flrbbarkeit and light brown character- 60 with a temperature of 120 ^c C teristic coloring of the fiber. The fibers are therefore not nearly as suitable for practical use as chemical chemicals or alkalis or even as the fibers according to the invention, which in addition to their acids, with the exception of concentrated hot acids, have excellent flatness properties, excellent toughness, flexibility, Degree of whiteness and 65.

Have dyeability. _Example 2 The fibers according to the invention can be used to dissolve 600 g of a melamine-aldehyde precone Position of various products, such as fabrics, densates with a Hj droxymethylierungsgrad of

23

O <& i J

3.0 in 400 g of dimethylformamide, 1000 g of a solution with a precondensate concentration of 60% by weight) being obtained. The solution is kept at 30 ° C until the viscosity, measured at 35 ⁰ C using a rotational viscometer of type B, reached 1100 poise, and the solution mm through a nozzle having holes with a diameter of 0.25 in a nitrogen gas atmosphere at a temperature of 280 ° C to effect dry-reaction spinning. A melamine-aldehyde resin fiber is obtained with a titer of 15 denier and a swelling capacity in water of 1.23, which is wound up at a speed of 12 m per minute. The flame retardancy properties are the same as those of the fiber of Example 1, as are toughness and dyeability. The shrinkage of the fiber in the air at 230 ° C is only 3%.

Example 3

Dissolve 0.2 g of polyethylene oxide with a molecular weight of 2,600,000 in 140 g of water. 259.8 g of a melamine precondensate with a degree of hydroxymethylation of 3.0 are then added. The mixture is stirred for 2 hours at 160 ° C., the pH value being adjusted to 7.0 for the preparation of the spinning solution. The amount of polyethylene oxide in the mixture is 0.077% by weight. The solution is kept at 30 ° C. until the viscosity determined with a type B rotary viscometer reaches 760 poise and excellent spinnability is achieved. The solution is then mm through a die having four holes with a diameter of 0.25 in air at a temperature of 210 ⁰ C pressed to a stable dry-response spinning at a rate of 40 m to reach per minute. The fibers obtained in this way are in the form of a colorless, transparent product with a swelling capacity in water of 1.23 and a titer of 9 denier. The tensile strength and elongation of the fibers are 2.3 g / denier and 11%, respectively. The fiber

has the same excellent flame retardancy properties like that of example 1. The shrinkage of the fiber at 230 ° C. in the air is only 2%. The fiber can be dyed excellently. In particular leaves with an acidic dye dye absorption of 100% at 98 ° C reach. The one determined in accordance with JIS L 0843-71 The lightfastness of the dyed fiber belongs to the sixth category. The hygroscopicity

ίο of the material is at 20 ° C and 65 ° / o more relative Moisture 6.2%>, which is essentially the value of cotton equates. The fiber is characterized by excellent water resistance, d. that is, it practically does not shrink at 120 ° C in water. The fiber is quite resistant to chemicals, with the exception of highly concentrated acids at high temperature.

Example 4

To prepare an aqueous solution, a completely saponified polyvinyl alcohol with a degree of polymerization of 1700 is dissolved in water at 95 ° C. with stirring. A melamine-aldehyde precondensate with a degree of hydroxymethylation of 3.0 is then dissolved in the solution with stirring at 60 ° C. for 2 hours and the pH of the solution is adjusted to 7.5. Then, aqueous solutions containing 0 to 30 wt are ⁰ / "polyvinyl alcohol based on the total weight of melamine resin and PoIyvinylalkohol containing, was prepared. The aqueous solutions with different polyvinyl alcohol ratios are stored at 25 ° C. until viscosities of 1700 to 1800 poise are reached. The solutions are then injected through a nozzle with four holes each 0.5 mm in diameter in nitrogen gas having a temperature of 250 ° C. to effect dry-reaction spinning at a speed of 80 m per minute . In this way fibers with a linear density of 7 denier are obtained. The results of the spinning process are summarized in Table I below.

Table I.

No. Polyvinyl alcohol Spinnability Swelling capacity Tear resistance node Flame crowd {%) (Broke the fibers in water (g / d) strength strength*) per hour) 4-1 0 (Winding up _ ___ . . , was not possible) 4-2 0.02 27 1.28 1.9 0.8 O 4-3 1 12th 1.28 2.0 0.9 O 4-4 10 5 1.27 2.0 1.2 O 4-5 20th 4th 1.30 2.1 1.4 O 4-6 30th 1 1.32 2a 1.4 © 4-7 40 0 1.32 23 1.5 © 4-8 50 0 1.34 2.3 1.6 X *} Flame-faced cat:

© Essentially non-flammable, self-extinguishing, but considerable smoke development x Flammable and violent smoke development

29 30

The above results show that the spinning is transparent. The pH of the solution is 6.7

availability (expressed by the frequency of the fiber The degree of hydroxymethylation of the Mclamin-Vor

fraction) with increasing amount of polyvinyl alcohol condensate is 2.5. Hence dii

is greatly improved. If there is no polyvinyl alcohol amount of that contained in the solution, with polyvinyl

hol, the winding at a speed 5 alcohol-modified precondensation is as 255 g, true

a speed of 80 m per minute is impossible. At 1% the amount of unmodified precondensate ii

Polyvinyl alcohol is made up of some 79% by weight of the total pre-condensate

Scope possible. With amounts above 10% it works. Therefore, the amount of polyvinyl alcohol is

stable winding. The toughness and the kno- 21% by weight (based on the weight of the ge

The strength of the yarn decreases with increasing total pre-condensate -f polyvinyl alcohol). Nacl

Amount of polyvinyl alcohol. The increase in the Kno- termination of the reaction is the concentrator

tenacity is particularly noteworthy. It leaves the melamine pre-modified with polyvinyl alcohol

There are also improvements in the flexibility of the condensate observed in the 42.5 weight-Ύι aqueous solution

th. On the other hand, a reduction in (based on the solution). The added boric acid

Flame resistance and an increase in the amount of smoke amounts to 5% by weight (based on

winding through the incorporation of the flammable poly- den polyvinyl alcohol).

vinyl alcohols. It is therefore assumed that the aqueous solution is at a temperature

men that the maximum amount of such water-soluble from 30 ⁰ C is kept. Can do it for 10 hours

Licher polymers 40% by weight, based on the neither a sharp increase in viscosity nor an Ent

The total weight of the melamine resin and the other 20 glazing can be determined. When the viscosity is dci

resins other than melamine. Solution prepared with a rotary viscometer

η. 15 type B is determined, is 1500 poise, di <

^1S P solution in the dry reaction spinning process

12.3 g of polyacrylamide are dissolved with a mole insert. The solution is through a nozzle with it Kular weight of 5 500 000 in 478 g of an aqueous 25 ben holes with a diameter of 0.2 mm ir Solution of 120 g (4 mol) of formaldehyde with an air with a temperature of 290'- 'C extruded. urr pH 7.0. Then the solution is added to evaporate the water and the han at the same time with 126 g (1 mol) of melamine and causes the reaction to harden. The fiber is moving at a speed a temperature of 60 ° C through, being wound speed of 260 m per minute. The number 616.3 g of an aqueous solution of one with polyacrylic 30 of the fiber breaks per hour is only two, amide modified melamine precondensate is obtained. However, if an aqueous solution is used. The solution is colorless and transparent. The hydroxy- the only modified one with polyvinyl alcohol Degree of methylation of the melamine precondensate is removed from melamine precondensate, but no boric acid 3.6. The dissolved reserve is accordingly, and the solution under the same conditions The amount of the bonded polyacrylamide poly- 35 used as the spinning solution results in a number merisat contains 246.3 g, which is a concentration of the fiber breaks per hour of 74. It is therefore klai Corresponds to 40% by weight. The amount of polyacrylic can be seen that the spinnability is through the Einamidpolymerisats The boric acid and polyvinyl alcohol work in the precondensate 5% by weight, based on the total weight of the spinning solution, is increased considerably. Precondensate and polyacrylamide. The solution becomes 40. The fiber has a linear density of 4 denier and a stored at 20 ° C until a viscosity of swelling capacity in water of 1.36. The tear strength; -1600 Poise has set. To achieve the dryness and the elongation are 2.8 g / denier resp. ken reaction spinning then the solution becomes 20%. The fiber has the same excellent properties through a seven-hole nozzle with flame retardant properties like the fiber of the BeiDiameter of 0.15 mm each in one at 250 ° C 45 game 1 and shows a in the air at 230 ° C sustained atmosphere extruded. The melamine resin shrinkage of only 3%. fiber with a swellability in water of 1.20

Example 7 is carried out at a speed of 90 m per minute wound up. The fiber has a titer of 50 g of polyvinyl alcohol (Polymerisations-9 Denier, a tear strength of 2.6 g / denier and 50 degrees 2400, degree of saponification 98 5%) in 640 g of a an elongation of 13%. The fiber has an aqueous solution that contains 90 g (3 mol) of formaldehyde and Signed flame resistance and is characterized by containing 2.5 g of boric acid and a pH of 7 legs particularly low smoke development and sits through. To the solution is then added 126 e (1 mol) the remeltability. The dyeability and the melamine too and causes the hydroxymethylation lightfastness of the dyed fibers are as good as the reaction of the melamine for 1 hour at 50 "C. the values obtained according to Example 1. After finishing the reaction is the resulting one Example 6 Aqueous solution which has a pH of 7.1.

"," -. "". ... .. ". . ,, _t completely colorless and transparent. The Hvdroxy

^ ^TO 13 ⁰ U ⁸ ^ "" -. '?? ¹¹⁸ ? ^ ^SUng '1? -? ° ^g ? ^ ^{oil) meth} y ^ degree of the melamine precondensate

Contains formaldehyde and 2.7 g of boric acid and carries a 60 2.3. Accordingly, 245 g are obtained in the solution

* £ '?? <?? ⁷ '°. ^{ouch knows} ·? ^b *, ™ \ ^ ^8. ^ y ™ * ¹ - ^a «™ t polyvinyl alcohol modified precondens-SS ¹¹⁰ I ^{ χ? ^yme "u T ^g i L ^{f Ver} ^ ^fu " ifi ^rad sats what a concentration in the solution of 99.9 »/«). The mixture is stirred to form 30 weight - «/», based on the total weight of the

a solution at a temperature of 95 ° C. Then solution. is equivalent to. The amount of unmodified is added to 126 g (1 mol) of melamine and the 6 _S precondensate is 80% by weight, so that the hydroxymethylation reaction of the melamine is 20% by weight, based on the amount of polyvinyl alcohol 1.5 hours by elev. zen to 60 ° C. The aqueous solution, which is based on the total weight of the precondensate and the polymer, is completely colorless and contains vinyl alcohol; _β ".""*"., ♦ ,. n ^ a ,, «» -

amount is 5 trade · / «(based on the polyvinyl alcohol).

The solution is maintained at a temperature of 50 ° C and, after a viscosity of 890 poise is reached, through a nozzle having 20 holes with diameters of 0.10 mm finem DurcMührung under the dry-response Spinnverfahreiis in at 32G ^V C The resulting fiber with a titer of 2 denier is wound onto a spool at a speed of 500 m per minute. The fiber has a swellability in water of 2.78. The fiber is then heated in nitrogen to a temperature of 200 ^° C. for 10 minutes in order to effect hardening. The fiber produced in this way shows a swelling capacity in water of 1.09.

The tear strength and percentage elongation are 3.8 g / denier and 10 ⁰ zo, respectively. The fiber obtained in this way has the same excellent flame resistance as the fiber of Example 1. The shrinkage of the fiber is only 2 ° o at 230 ° C. in air.

Example 8

375.5 to an aqueous solution, are 54 g of polyvinyl alcohol (having a polymerization degree of 1700 and a saponification degree of 99.9 ⁰ Zo) and containing 0.40 g of borax to 126 g of melamine and 112.5 g of paraformaldehyde g (purity 80 °, o). The hydroxymethylation is carried out for 1 hour at 80 ° C., after which the degree of hydroxymethylation of the resulting precondensate is 2.7. Accordingly, the solution contains the precondensate modified with polyvinyl alcohol in an amount of 261 g, which corresponds to a concentration in the solution of 42.5% by weight, based on the total weight of the solution. The amount of polyvinyl alcohol contained in the precondensate is 21% by weight, based on the total weight of the precondensate (including the portions modified and unmodified with polyvinyl alcohol) and the polyvinyl alcohol. The added Boraxmenge is 0.74 weight ⁰ 0, based on the polyvinyl alcohol.

The solution is kept at a temperature of 30 C for 80 hours, with none strong increase in viscosity can still be observed devitrification. After the viscosity is 1800 poise has reached, the solution is through a nozzle with seven holes each with a diameter of 0.2 mm to achieve dry reaction spinning in air at a temperature of 290 ° C extruded. No fiber breakage can be observed at a winding speed of 260 m per minute, the fiber can easily be wound up even at a speed of 500 m per minute. the Coiled fiber is then subjected to a heat treatment in air to cure the resin and a fiber with a water swellability of 1.20 and a linear density of 2 denier result. The fiber has essentially the same properties as that produced according to Example 6.

Example 9

Dissolve 50 g of polyvinyl alcohol (having a polymerization degree of 2400 and a Vcrscifungs-Rrad 98.5 ⁰ Zo) in 640 g of an aqueous solution (having a pH of 7). which contains 90 g (3 mol) of formaldehyde and 2.5 g of boric acid. 126 g (1 mol) of melamine are then added to the resulting solution and the hydroxynesethylation is effected for 1 hour at 50 ° C. After the reaction has ended, the pH is of the solution 7.1, while the degree of hydroxymethylation of the precondensate reaches a value of 2.3. The amount of polyvinyl alcohol-modified precondensate in the solution is 245 g, which corresponds to a concentration in the solution of 30% by weight, based on the total weight of the solution , is equivalent to. The amount of unmodified precondensate in the entire precondensate is 80%, so that the result is a polyvinyl alcohol amount of 20% by weight, based on the weight of the entire precondensate and the polyvinyl alcohol. The amount of boric acid added is 5 weight ⁰ 0, based on the weight of the polyvinyl alcohols.

The solution is kept at 50 ° C and, after the viscosity has reached 89C poise, in air with a temperature of 320 ° C, using a nozzle with 20 holes, each have a diameter of 0.10 mm. The dry reaction spinning process is carried out at a speed of 500 m per minute. The fiber obtained has a swelling capacity in Water of 2.86. Then the spun fiber is heated with heated rollers and a hot plate, each heated to a temperature of 140 ° C, brought into contact and then at a speed wound onto a reel at a rate of 1000 m per minute, whereby (because of the difference the speeds of the spinning process and winding) a stretching process in the heat 100 ° 0 is effected. The wound yarn is 15 minutes in a nitrogen atmosphere at a Temperature held at 200 ° C to complete the curing reaction and prepare a fiber, which has a swellability in water of 1.14 and a titer of 1.5 denier.

The tensile strength and the percentage elongation of the fiber obtained are 5.0 g / denier and 8 ° / u, respectively. The fiber shows excellent flame-extinguishing properties and is thermally infusible. The shrinkage of the fiber in the air at a temperature of 23O ⁰ C is only 3%. The fiber is also distinguished by excellent dyeability, in particular with an acidic dye. In particular, a dye absorption of 100% can be observed at 98 ° C. The light fastness of the dyed fiber corresponds to the sixth category, while the hygroscopicity of the fiber at 20 ^ C and a relative humidity of 65 ⁰ Zo amounts to 6.3 ⁰ Zo, which makes the fiber suitable for clothing. Furthermore, the fiber shows good resistance to hot water, since no significant shrinkage can be found in water at a temperature of 120 ° C. After all, the fiber is insoluble in normal solvents.

Example 10

^{An aqueous solution of N-methylolmelamine with a resin concentration of 70 0 is} prepared by dissolving a commercially available N-methylolmelamine (degree of methylolic acid = 3.0) in water at 60 ° C. with stirring for 1 hour. the

23 64

l / l

The solution is aged for 4 days at 25 ³ C until the viscosity (determined in the manner indicated above) is 450 poise . The nozzle has holes with a diameter of 0.25 mm. One irhalt a fiber of lflO ^e / * Melanun-formaldehyde resin. The whiteness of the fiber is 0.85, the titer 16.5 denier, the tensile strength 2.3 g / denier, the elongation 1 i "ο ίο and the swelling capacity in water 1.22. The J / i value amounts to 0.002, and it can be shown by X-ray analysis that the fiber is completely amorphous. After the evaluation, it is found that the fiber does not burn when it is brought into contact with a flame, but only glows and emits an extremely small amount of smoke If the flame is gone, the glow stops immediately, and no smoldering can be observed. The material shows no tendency to melt and decomposes only slowly when heated to a temperature of 500 ° C. The thermal shrinkage of the fiber in air is at 300 ⁰ C 6 ⁰ Zo, while the dyeability of the fiber is satisfactory. In particular, there is an absorption of an acidic dye from the dye liquor of 100% at 98 ° C. The lightfastness of the fiber dyed with this dye is if it is determined according to JIS regulation L 0843-71, to be classified in category 6.

The moisture absorption of the fiber at 20 ° C and a relative humidity of 65 ° 0 6.2 ⁰ Zo, a value which is similar to that of cotton. On the other hand, the fiber does not shrink when it is placed in hot water at a temperature of 120 ° C. Thus, in spite of the fact that the fiber has moisture absorbency similar to that of cotton, dimensional stability in hot water is very high, which is a characteristic of the fibers of the present invention.

Example 11

With gentle stirring are employed, a mixture of 973 g of a formaldehyde solution (an aqueous solution containing 37 wt ° / o formaldehyde [12 moles of formaldehyde]) and 189 g (1.5 moles) of melamine for 15 minutes at 85 ^C to C . The reaction mixture is then concentrated by evaporation for 3 hours with stirring. 920 g of a concentrated aqueous solution of N-methylolmelamine are obtained which contains 49% by weight of N-methylolmelamine with a degree of methylolation of 5.9. After aging the solution for 48 hours at 25 ° C until the solution is spinnable (i.e. has a viscosity of 230 poise), the reaction-spinning process is carried out, the solution being passed through a nozzle with holes with a diameter of 0, 20 mm into a nitrogen atmosphere maintained at 250 ° C. A fiber with a titer of 12 denier is obtained.

The fiber, which consists entirely of a melamine-formaldehyde resin, is colorless and transparent and has a swelling capacity in water of 1.26, a dn value of practically 0, a tear strength of 2.8 g / denier and an elongation of 14% . The X-ray analysis shows that the fiber is completely amorphous. The fiber is not flammable and only wilts. when brought into contact with the flame. When the flame is removed, the glow stops immediately, and no smoldering can be observed. On heating to a temperature of 500 ° C. no melting and only gradual decomposition can be observed. When heated in air to a temperature of 300 ° C, the shrinkage is only 5%. The dyeability of the fiber is excellent, especially when acidic dyes are used. In particular, when the fiber is immersed in an acidic dyeing liquor is, the dye at 98 ⁰ C to 100 ^o / o absorbed, wherein there is excellent coloring.

The lightfastness of the fiber dyed with the acidic dye is classified in category 5. the Moisture absorption is 7.6 °, '«what the fiber for making textiles for making used by clothing makes it suitable. The fiber is against various chemical Very resistant reagents. In particular, the fiber is against treatment with various organic Reagents and alkalis completely stable, which is also true of the acids, with one exception the hot concentrated acids.

Example 12

It is a mixture of 730 g aqueous formaldehyde solution (37 wt ⁰ "formaldehyde [Formaldehyde 9MoI] containing) and 189 g of melamine (1.5 moles) for 15 minutes at 75 ° C with stirring to. After the reaction mixture has been concentrated by evacuation at 60 ³ C for 2 hours, 835 g of an aqueous solution which has an N-methyloimelamine concentration of 54 ⁰ O is obtained. The degree of methylolation of the N-methylolmelamine obtained is 5.4. The solution is divided into 5 equal portions, which are transferred to 5 containers and placed in temperature-constant vessels that are kept at 20, 30, 40, 50 and 60 ³ C. The relationship between the spinnability and stability of the solutions and the aging time is observed, the results obtained being shown in Table II below. In the table, the spinnability is given as the period of time during which spinning is possible of each solution immersed in a bath at a certain temperature, the period of time being counted from the beginning of the immersion. The spinnability is examined via the fiber formation properties of each solution by dipping a glass rod into the solution and quickly pulling it out. The stability of the solutions given in the table below is given as gel time, which is determined from the point in time at which the solutions lose their fluidity.

table II Spinnable Gel time No. Aging Period temperature fhours) (Hours) ( ⁰ C) 15 to 51 60 12-1 20th 11 to 33 40 12-2 30th 4 to 17 21 12-3 40 1 to 3 4th 12-4 50 1 12-5 60

If the aging temperature is higher than 50 ° C, the aqueous N-methylolmelamine solution loses not only in a short time; it can be spinnable, but

which also their fluidity. Therefore, it can be seen that such aging conditions are not suitable according to the invention.

A TEU of the solution held at 40 ⁰ C (Nr. 12-3 Table II) is removed, if the solution viscosity, determined is using a rotational viscometer of type B, 540 poise, after which the Reaktionsverspinnen is carried out by the material through a 0.30 mm diameter nozzle into an air atmosphere

presses, which is kept at 240 ° C. The fiber obtained has a titer of 13 denier, a tensile strength of 2.5 g / denier, an elongation of 10 "Ve, a swelling capacity in water of 1.25, a type of

Value of 0.001 and is completely amorphous. The fiber is flame-retardant and infusible like that of Example 10 and has superior dyeability, especially in the case of acidic dyes (e.g. the red dye C. L Acid Red 89), where one

ίο a dyed fiber with a clean color is obtained.

Claims (13)

Patent claims: 1. Flameproof, infusible fibers, consisting of a hardened melamine-aldehyde resin or an alkyl ether thereof, a hardened condensation product of the melamine-aldehyde resin and a compound co-condensable therewith and / or a hardened physical one Mixture of the mdamin-aldehyde resin with a thermosetting or thermoplastic, fiber-forming. Polymer, as well as optionally customary fiber additives, the melamine-aldehyde resin in all cases at least 60% by weight of the fibers. 2. Fibers according to claim 1, characterized in that they have a swelling capacity in water of less than 2.0, a birefringence of less than 0.02, a degree of whiteness according to Judd of less than 0.7, a strength of 1.6 to 5.0 g / denier and / or ^{show a shrinkage of less than 10 e} / o when heated to 300 ° C. 3. Fibers according to claim 1, characterized in that they are the melamine-aldehyde resin Condensation product of a melamine, an N-substituted derivative thereof, guanamine, a substituted guanamine and / or a mixture thereof with an aliphatic, cyclic or aromatic aldehyde or a mixture of these aldehydes. 4. Fibers according to claim 1, characterized in that they consist essentially of the cured condensation product of a melamine-aldehyde resin and 0.02 to 40 wt. ⁰ Ό of a co-condensable compound or a cured physical mixture of the melamine-aldehyde resin with 0.02 to 40% by weight of a second fiber-forming polymer. 5. Fibers according to claim 4, characterized in that they are used as the second fiber-forming polymer contain a water-soluble, thermoplastic polymer. 6. Fibers according to claim 5, characterized in that they are a water-soluble, thermoplastic polymer, a polyvinyl alcohol with a degree of polymerization of 500 to 3200 and a degree of saponification of 75 to 100 mol ⁰ Zo in an amount of a to 40 wt% based on the weight of the mixture. 7. Fibers according to claim 6, characterized in that they contain 0.2 to 20 wt% boric acid or 0.02 to 10% by weight of a borate, based on the weight of the polyvinyl alcohol. 8. A method for producing the fibers according to any one of the preceding claims, characterized characterized in that a solution of a melamine-aldehyde precondensate or the at least 6OGew.-% of this pre-condensate containing fiber raw materials in a manner known per se spun in a heated atmosphere and at the same time the solvent evaporates and the precondensate hardens. 9. The method according to claim 8, characterized in that there is a fiber raw material through Condensation of a melamine with an aldehyde in the presence of a second fiber-forming polymer formed melamine-aldehyde precon- densat is used, the 0.02 to 40 wt .- · / «of the second Contains polymer 10. The method according to claim 8, characterized in that that a physical mixture of a melamine-aldehyde precondensal is used as the fiber raw material with 0.02 to 40 wt .-% of a second fiber-forming polymer is used. 11. The method according to claims 8 to 10, characterized in that a solution is used, having a certain with a rotary B type viscosity of 40-3600 poise and the fibrous raw material in a concentration of 20 to 85 wt ⁰ / ·, Based on the weight of the solution 12. The method according to claims 8 to 11, characterized in that a solution with a pH of 5 to 9 is used 13. The method according to any one of claims 8 to 12, characterized in that a solution of a melamine-aldehyde precondensate or the fiber raw material containing at least 60% by weight of this precondensate into an air or an atmosphere containing an inert gas heated to a temperature of 170 to 320 ° C spun into a fiber which has a swellability in water of 1.5 to 3.0, the fiber a temperature of more than 100 ° C in the heat with a draw ratio of at least stretched 1.1 times the original length of the fiber and then the stretched Fiber to a sufficient temperature by heating for a sufficient time hardens a fiber with a swellability in water of less than 1.5.