DE2313205C3 - Flame retardant fibers and processes for their manufacture - Google Patents

Description

The invention relates to flame retardant object of the invention is to create difficult

isern made from a mixture of polyvinyl alcohol and 60 flammable fibers made from a mixture of polyvinyl chloride, which contains other additives, vinyl alcohol and polyvinyl chloride with superior i wie on a process for their production. Flame resistance, strength and light resistance that

So far, many methods have been proposed that can be manufactured at low cost and η a flame retardant for adhering to not the disadvantages of the known polyvinyl alcohol aesthetic Have fibers or to react with these 65 polyvinyl chloride fibers. bring and thereby these flame retardant or according to the invention are flame retardant to make it unstable. Some of these workings are made from a mixture of polyvinyl alcohol and fibers are technically used. However, in order to be made of polyvinyl chloride, which also contains other additives,

created, which are characterized in that the fibers consist of polyvinyl alcohol with an average degree of polymerization of 500 to 3000 and a degree of saponification of at least 99.5 mol percent polyvinyl chloride and boric acid and optionally tin (Tv> oxide or tin (rv> acid, the weight ratio from polyvinyl alcohol to polyvinyl chloride is 90:10 to 55:45, the boric acid content is 0.02 to 0.5 percent by weight based on the weight of the polyvinyl alcohol, and, if present, the tin compound content is 0.1 to 5 percent by weight based on the total weight of the polymer is, wherein the fibers in the direction of the fiber axes are molecularly oriented and have a hot water resistance of at least 110 ⁰ C.

The manufacture of flame retardant fibers from a mixture of polyvinyl alcohol and polyvinyl chloride of the type indicated above takes place according to the invention by a method that thereby is characterized in that a partially saponified polyvinyl alcohol with an average degree of polymerization of 500 to 3000 and a degree of saponification of 88.5 to 99.5 mole percent, 0.5 to 4 weight percent based on the weight of the polyvinyl alcohol Boric acid and optionally a tin compound with an average particle size of not more than 20 microns, which consists of tin (IV) ~ oxide and / or stannous (IV) acid, can be dissolved in water, the obtained aqueous dispersion with an emulsion of polyvinyl chloride with an average particle diameter of not more than 1000 Å is mixed to form a spinning solution, the weight ratio of Polyvinyl alcohol to polyvinyl chloride 90:10 to 55:45 and the level of civil bond, if any, from 0.1 to 5 percent by weight based on total weight of the polymers, the resulting spinning solution is placed in an alkaline coagulating bath to form is spun by gel threads, the gel threads are stretched between rollers, then in an acidic bath neutralized and stretched again in moist heat, the threads before or after the second stretch be washed with water until the residual boric acid content reaches 0.02 to 0.5 percent by weight, the threads are dried, the dried threads are then stretched in dry heat subjected to a total draw ratio of at least 10 and then subjected to a shrink treatment will.

The fibers according to the invention have a sufficiently high flame resistance compared to hitherto known fibers. In particular, according to the invention, synthetic fibers with a superior Obtained flame retardancy, superior light resistance and high strength.

A special feature of the fibers according to the invention is that the polyvinyl alcohol-polyvinyl chloride fibers Contains boric acid. When boric acid in the polyvinyl alcohol-polyvinyl chloride fibers is included, the stretchability of the fibers is significantly improved. This allows the fibers to be on one Can be stretched to an extent that has not previously been achieved, for example to an overall stretch ratio of at least 10 and, under preferred conditions, more than 12, and that a higher Strength is achieved, which cannot be expected due to the known polyvinyl alcohol-polyvinyl chloride fibers was e.g. B. a strength of at least 6 g / den. It has also surprisingly been found that, although the usual polyvinyl alcohol-polyvinyl chloride fibers have poor water resistance, if they are not acetalized, the fibers according to the Invention, which have been extended to a large extent, due to the boric acid contained therein have sufficient water resistance without acetalization. It is believed that this is due to the fact is due; that if the boric acid containing Polyvinyl alcohol-polyvinyl chloride-dope

solution is spun in an alkaline coagulating bath, first a gelation of the same occurs and then freshly spun gel shutters with a homogeneous one Cross-sectional area are obtained and that by the subsequent drawing in of water the gel

is thread the threads under at a higher ratio Forming threads of a homogeneous structure with a practically circular cross-section can be stretched can.

Since the fibers according to the invention are not acetalized

ao may reduce the flame resistance and lightfastness, which inevitably occurs during acetalization, can be avoided, and these properties can also be significantly improved.

A second feature of the invention is based on the discovery that stannous oxide and stannous acid effective flame retardants for polyvinyl alcohol-polyvinyl chloride fibers are.

It has heretofore been known that antimony trioxide (Sb ₈ O ₃ ) has a synergistic effect with polyvinyl chloride as a flame retardant, and it is used in large amounts. On the other hand, it is also known that tin (IV) oxide (SnO ₄ ) has a synergistic effect with polyvinyl chloride. However, the latter was hardly used because it

effect is inferior to antimony oxide or at most equivalent and is also very expensive.

Attempts have been made to use flame-retardant polyvinyl

Manufacture alcohol-polyvinyl chloride fibers by adding a tin salt of a strong acid to an acetalizing bath for the fibers with the incorporation of stannic acid into the fibers (DT-OS 2 029 734). As will be shown in detail later, the flame resistance of the fibers is improved, however their strength and, in particular, light resistance deteriorates. For example, films were made from a Mixture of a polyvinyl alcohol-polyvinyl chloride polymer composition made with stannous oxide, stannous acid or antimony trioxide, and the flame retardant properties each film was expressed in terms of limiting oxygen index (LOI) values Oxygen index, determined according to ASTM method D-2863-70). The results are in Table I. reproduced.

Table I.

Amount of additives (%)

Sb ₁₁ O ₃

SnOg

Cinnamic acid

Polymer

Polyvinyl chloride

2
36

35.5

36.5

Polyvinyl alcohol

19.6
19.5

19.5

Ratio of PVA / PVC

75/25

27
31

32.5

67/33

5 ⁶

_Λ j »; _nl > to a larger extent, SnO ₄ or ZUm (IV) -

As can be seen from Table I, SnO ₄ or ^ f "Ä ^ _{length vou} 0.1 to 5 percent by weight

ZinnaV> acid a far larger f ammverzögerong- acidem ^ ^ ^ ^^ ^, ^

effect on the polyvinyl alcohol-polyvinyl chloride-related dw

System as Sb ₄ O ₃ . This was an expected result. ^ '^ mn-acid is preferred / * - stannic acid.

It is assumed that this result can be attributed to the following causes: if fibers, which if " ^e _ ^ ° £" XL. ^, ^ _N , the flame retardation of poly ^ ylalk ^ ol-Polyvinylchlorid exist, ^^^^^! ä ^ JS ^ SZ or those, which to the Anümontooxid as Flammverao- J ***** and if the amount 5 weight percent, containing detergent Polyvmylaikchol-Polvi- JJ * «J ^ * ^ e properties of fibers, such as: wwMeehtert Thus «ίη ^« ch m of heat under melting. On the other hand, for example, strengthened strands when fibers made of polyvinyl alcohol-polyvinyl quantities outside the above range _{contain SnO 1} or cinnamic acid, in good condition
Fire be gesetrt, a reduced tendency to As angegebrüten above, the fibers from the melt, however, immediately before the melting * s achieving ^ ^"high * ^A - ^ SS üSiÄ2 the polymer is cured and infusible with sufficient water, b" tenigk "t both m humid a high temperature, and its carbonization heat as well as in * «* f ^Q 5warm ^""**" ** is promoted. It seems that polyvinyl alcohol will become an important part of the hardening reaction of the polymer and that the fibers will be mocularly onenterted to a shrinkage treatment Further, it is believed that the polyvinyl chloride *> and also crystallize so that a strength of hydrogen chloride gas at the time of burning preferably develops at least 3.5 g / den and one water and the hydrogen chloride gas with SnO ₈ or resistance of at least 10 C tin (IV ) -acid reacts with the formation of a tin chloride. ·· «j π ej
that is effective in preventing the burning process of the fibers in the manufacture of the fibers according to the invention. Thus, the polyvinyl might »5 to boric acid is partially saponified polyvinyl alcohol-polyvinyl chloride-SnO, - added or tin (IV) -säure-, and the mixture is achieved a particularly good Flammverzögerungs- to 13O ⁰ C in water at 90 masses. The solution will have an effect of 40 to 75 C and cool with an aqueous emulsion of polyvinyl

To obtain fibers with high strength, chloride should be mixed and then kept at 40 to 75 ° C

the polyvinyl alcohol defoamed a medium polymerization 30 to achieve a spinning solution. the

degrees of 500 to 3000, and a high spinning solution kept at 40 to 75 ° C is in a

To maintain water resistance, the polyvinyl bath should be spun that has alkaline dehydrating salts

alcohol has a degree of saponification of at least 99.5 After various treatments, including

Own mole percent. The inclusion of polyvinyl lent roll stretching, neutralization, moist heat: -

Chloride is essential for achieving flame retardancy. The threads are 35 stretching and water washing

straight fibers. The weight ratio of poly- dried, drawn in dry heat and treated

vinyl alcohol to polyvinyl chloride should be 90:10 to shrink. If necessary, the threads can after

55: 45. For smaller quantities of polyvinyl the rinsing stage with an aqueous solution of salts

Chloride of a lower value given in the above will be treated.

achieved insufficient flame retardancy, and at 40 An essential feature of the process of making it larger Amounts of polyvinyl chloride is both the position of the fibers according to the invention is Both the strength and the light resistance of the spun gel threads are maintained to a high degree ten fibers. be stretched. However, in order to have superior fibers

The polyvinyl properties usable in accordance with the invention to easily produce are various

Chloride is not just a homopolymer of vinyl 45 grafts required. First of all, the

chloride, but can also be a copolymer made of applied polyvinyl alcohol, preferably a medium

At least 75 mole percent vinyl chloride with an other degree of polymerisation of 500 to 3000. If

their comonomers and a grafted vinyl chloride. the average degree of polymerization is less than 500

Copolymer, on which polyvinyl alcohol is grafted, makes it impossible to produce fibers of high strength

has been (the ratio of grafted so to be obtained, and if it is over 3000, the visco-

Pdyvinyl alcohol usually does not exceed 5 molar strength of the spinning solution at usual concentrations

Percent). If that with polyvinyl alcohol the polymer is too high, and the spinning process can

grafted vinyl chloride copolymers are used, are not carried out under good conditions,

the amount of polyvinyl alcohol in the graft when the concentration of the polymer is decreased

Copolymers to the amount of polyvinyl alcohol below 55 is used to reduce the viscosity of the spinning solution,

Calculation of polyvinyl alcohol-polyvinyl chloride can not be fibers with superior properties

Ratio admitted. can be obtained. The degree of saponification of the polyvinyl

In order to maintain the strength and water resistance, the alcohol is preferably 88.5 to 99.5 molar proportions, the boric acid is in an amount of 0.02 to cent. Even if the one used to make the dope 0.5 percent by weight, based on the polyvinyl alcohol to be used 60 is lower alcohol incorporated into fibers. If the amount has a degree of saponification, fibers with high Boric acid is outside this range, water resistance cannot be obtained because it is increased the stretchability of the spun threads soapy during the spinning process due to the expected and the desired results of the applied alkaline coagulating bath occur. In cannot be obtained. Instead of boric acid 65 depending on the concentration of the alkali A boric acid salt or boron oxide can also be used to make polyvinyl alcohols with a degree of saponification Get a turn. of less than 88% not completely

To increase the flame resistance of the fibers to a degree of saponification of at least 99.5%, and saponify it

7 8

cannot achieve sufficient water resistance dehydration-coagulation process under deterioration

will. Turn of a Glauber's salt bath.

The spinning process according to the invention must be made from the polyvinyl alcohol-polyvinyl chloride

a relatively low temperature of 40 to 75 ⁰ C emulsion and boric acid obtained spinning

With regard to the stability of the emulsion, defoaming is done by setting it at 30 to

be guided. Let stand completely saponified polyvinyl alcohol at 75 ° C. The polyvinyl alcohol gels at

get with a degree of saponification of 99.5.% or more, a temperature below 30 ⁰ C, and at a temperature

have poor dispersion stability at low temperatures of over 75 ° C, the polyvinyl coagulates

At low temperatures and due to shear forces, they become chloride emulsions. In both cases, neither can

gels, which in turn leads to a blockage of the ver io spinning solutions obtained with good spinnability

turned filter candle material leads and life.

the duration of the filter material is shortened. During the process The total polymer concentration of the spinning solution

according to the invention, therefore, a partially saponified one is not particularly critical, but it usually lies

Polyvinyl alcohol, which has good dispersion stability at 8 to 20 percent by weight,

at low temperatures, but polyvinyl 15 The spinning solution thus formed is then in an alkali

alcohol-polyvinyl chloride fibers spun from a bad hot coagulating bath, in which instantaneous

provides water resistance, used during the gelation of the threads and subsequent development

of the spinning process by using an alka-watering of the same take place. For example, Na-

lischen coagulating bath is completely saponified, with trium carbonate alone or a mixture of alkali

when using a high stretching ratio, the »o hydroxide or sodium carbonate is mixed with Glauber's salt

j Production of polyvinyl alcohol-polyvinyl chloride- suitable.

Fibers Excellent in Hot Water Resistance It is desirable that the coagulating bath make one possible will. constant saponification of the partially saponified polyvinyl

The boric acid (H _S BO _S ) can be any water-soluble alcohol and be a boric acid salt sufficient to coagulate, and the amount thereof is as. A typical bath contains sodium hydroxide, preferably 0.5 to 4 percent by weight, calculated and Glauber's salt. The concentration of sodium and boric acid, based on the weight of the polyvinyl hydroxide, should be adjusted to 5 to 200 g / l alcohol. If the content is less than 0.5%, though it does not sufficiently gel depending on the degree of saponification, and if the polyvinyl alcohols used varies. If it is less than 4%, gelation is too violent, and if it is 30 5 g / l, saponification of the polyvinyl brittle gel filaments proceeds, which leads to processing alcohol not sufficiently proceeding, and gelation of the strands. Likewise, threads do not pass through the boric acid

The spinning conditions can be improved completely. If it is over 200 g / l, it will decompose

by adding a small amount of an organic acid or the polyvinyl chloride due to the strong alkali

inorganic acid to the aqueous polyvinyl alcohol. The concentration of Glauber's salt is preferred

Get boric acid solution to adjust the pH value at α to (α - 200) g / l (except for values

to 3 to 6 to prevent excessive gelation of less than 0), where α is the saturation concentration

is added or by adding a dispersant to the respective sodium hydroxide concentration.

is given to the polyvinyl chloride emulsion, which should be used when sodium carbonate is used

should then be added to dispersible 40 whose concentration should be at least 30 g / l because

it is weakly alkaline and does not provide sufficient

Copolymers of vinyl chloride, which causes less than soaping of the polyvinyl alcohols.

Containing 75 mole percent vinyl chloride units, after roller stretching, neutralizing and

Because of their poor dyeability, the threads are not preferred to stretch in moist heat

admitted. 45 water washed until the residual boric acid content

The polyvinyl particles in the emulsion should be 0.02 to 0.5 percent by weight, based on the

Have a particle size of not more than 1000 Å. weight of the polyvinyl alcohols. After application

If the particle size is larger, the spinning of the salt solution on the fibers will become the filaments

conditions poor, and the toughness of the obtained dried. If the remaining boric acid content

Fiber is low. 5 ° is greater than 0.02%, the stretchability of the threads

Since the polyvinyl chloride emulsion is bad at a temperature, and it is impossible to have good strength and

temperature of 75 ° C or above, and polyvinyl hot water resistance to be maintained. If he owes

alcohol is at a temperature of 30 ° C or below 0.5%, the fibers obtained do not have a hot

coagulated, the aqueous polyvinyl alcohol-boron becomes water resistance and become brittle.

acid solution first cooled to 30 to 75 ° C and then after stretching the threads in moist heat

then mixed with the polyvinyl chloride malsion so as to be in an oriented state to some extent

that there is a weight ratio of polyvinyl alcohol , the threads are during the following «

to polyvinyl chloride gives from 55:45 to 90:10. If water wash step not swollen, and disadvantages, di <

the amount of polyvinyl chloride less than 10 Ge due to swelling may decrease

weight percent is the dyeability that can be obtained. The length of the wash bath to ent

Tend fibers poorly, and if it is over 45%, far from boric acid should be sufficiently large. At

the toughness of the fibers is reduced. Because after the turn, when the threads are in moist warmth

the process of the invention, the stretching of the threads are stretched after the roller stretching, new

Can be carried out at a high ratio, neutralized and washed with water and unites

the filaments obtained have high tenacity, even if salt solution is applied to the fiber, the fibers

if polyvinyl chloride in a larger amount ent- washed with water in bulk, and dafae

hold is as in the FaD of the production of polyvinyl · the fibers got swollen. In this case came

chkmd polyvinyl alcohol fibers according to the usual the length of the wash bath be large, but srad di

. 509640/24!

t>

10

Properties of the threads obtained because of the disadvantages of swelling somewhat impaired.

The filaments are then drawn in dry heat at a total draw ratio of at least 10 and a shrinking treatment for molecular orientation and complete crystallization subject to the threads. The shrinkage is generally about 2 to 25%, preferably about 5 to 15%. With the usual method using a Glauber's salt bath, it is difficult to do that Increase total draw ratio to more than 10 unless special conditions are applied. According to the invention, it is possible to increase the total draw ratio to more than 10, and through The polyvinyl alcohol-polyvinyl chloride fibers can use such a high draw ratio Have flame resistance, high strength and superior water resistance.

According to a further embodiment of the invention, partially saponified polyvinyl alcohol and H ₃ BO) are dissolved in an aqueous dispersion of pulverulent SnO ₁ with heating, and the solution is cooled ^{to 30 to 80 ° C.} The solution is then mixed with an aqueous emulsion of polyvinyl chloride and the mixture is defoamed to give a spinning solution. The spinning solution is spun in an alkaline coagulating bath, and then the threads are subjected to various treatments including roller drawing, neutralization, drawing in moist heat, washing with water in the same manner as described above with reference to the method for producing fibers from polyvinyl alcohol, polyvinyl chloride and boric acid , Drying, stretching in

ίο subject to dry heat and shrinkage.

The powdery SnO ₁ or stannous acid is readily dispersible, and the mean particle size of the dispersed particles should not be more than 20 microns. If the size is greater than 20 microns, the particles may precipitate at the time of defoaming or block the filter candle material. Even if the particles are dispersed in the fibers, the area of their contact with the poly-

also low, and the flame retardancy effect is reduced.

Optionally, other flame retardants such as Sb ₁ O _{3 in} addition to SO or stannic acid can be used.

Table II

Poly-
merisa-
functional Composition of the fibers PVA /
PVC SnO,
(V.) be
ugen H.BO,
(V.) loading DFA Total-
stretching
ver
ratio Properties of the fibers Hot-
water-
persistent Firm light
persist Flame
ver
hesitated attempt
No. graddes
Polyvinyl Ver
soapy
Degree
(Mol
percent) Ver
ratio on the
Poly pulled
on PVA • 2 age
• 3 speed
(g / den) age
• 4 hesitating
• 5 alcohols 99.9 mcrcn • 2 CQ % (Degree) 1750 99.9 60/40 _ 0.10 _ 12th 116 5.7 70 3 1 , 1750 99.9 75/25 1 0.15 - 12th 116 8.0 90 3 2 400 99.2 75/25 1 0.18 - 10 112 3.1 87 3 3 1750 99.9 75/25 1 0.12 - 11th 103 6.8 85 3 4th 1750 99.9 50/50 1 0.11 - 10.5 114 2.1 45 3 5 1750 99.9 95/5 5 0.21 - 12th 117 8.5 93 1 6th 1750 99.9 65/35 0.08 0.01 - 9.3 108 3.8 70 3 7th 1750 99.9 80/20 1.5 0.7 - 11th 109 6.2 91 3 8th 1750 99.9 75/25 1 0.15 - 9a 108 4.2 88 3 9 1750 99.9 75/25 0.5 0.13 - 12th 116 8.1 90 3 10 1750 99.9 75/25 0.5 0.13 - 7th 101 3.4 90 3 11th 1750 99.9 75/25 0.5 0.13 35 7th 120 3.3 45 1 12th 1750 99.9 59/41 0.5 0 * 6 - 8th 103 3.8 60 3 13th 1750 99.9 59/41 0.5 0 * 6 33 8th 119 3.5 30th 2 14th 1750 59/41 (1.2)
* 7 0 * 6 32 7th 121 2.4 25th 2 15th

• 1 DFA: Degree of formafization of the fibers, which are heat treated and then acetylized with formaldehyde (mol percent

based on polyvinyl alcohol). ♦ 2 total stretching ratio: with the exception of tests 9, 11, 12 and 15, the specified total stretching ratios are 90!

the maximum stretch ratio at which the thread could be pulled without breaking. Thus these show W <

; in essence

lent the stretchability of the threads.

"3 Heffiwasserbeständigkeft: been cingetaedrt The threads in the water, while a weight of 1/500 g / d of the threads be under hung The immersed threads been inι an extent of 2 ^e C is heated per minute, and the temperature at which n represents the Fade and the weight fell was measured Di Tt ib di Hit

underwent. the

solved and g

• 4 lightfastness

J e heated, and the T

and the weight fell was measured. The temperature gives the Vhaltis of the remaining Festigkit d Fäd hd di F

• 5 Fta

, g. e temperature

git: The ratio of the remaining strength of the threads after the FA-I type O-meters were exposed. Fäd i h

c 100 Stand αΆ a bath

g: Threads with a total denier of 1800 denier were twisted about 90 turns per meter and knitted using a knitting machine to a fine with a work weight of 250 g / m * The knitted TW is evaluated according to the method described in JIS-L-1091 A-I. Grade 3 is sufficient, end Grade 1 is not he

* 6 The spinning solution contained no H ₁ BO, and the spun threads wimped with Vg Qi

end coagDÜcrt.

• 7 The spinning solution contained no H ₁ BO) and dfc spun FSde ^

and coagulates. The obtained FSdene were heat-bonded and with an Acsiungsbad the Zämtetr

rden enter Veg of a Gtan make-up bath ss

The threads are acetatized and treated at the same time with the incorporation of Zmn <rv> acidic.

cbtoridenÖBcl

The polyvinyl alcohol-polyvinyl chloride fibers according to the invention have the following important ones Characteristics:

(1) Since the fibers are obtained by spinning an H ₃ BO ₃ gel, the stretchability of the spun filaments is superior, and sufficiently high water resistance can be obtained without acetalization of the filaments obtained.

(2) The fine particles of SnO ₈ or stannous acid, which is an extremely superior flame retardant and is hardly soluble in water, acid or alkali, are uniformly dispersed in the fibers.

Furthermore, the fibers have flame retardancy properties, strength and light resistance.

The fibers according to the invention retain the superior dyeability property of polyvinyl alcohol-polyvinyl chloride fibers and can also be used for fibrous interior decoration material such as carpets or curtains can be used.

The fibers according to the invention achieve excellent strength and light resistance and excellent flame resistance only if all conditions, such as the degree of polymerization and the degree of saponification of the polyvinyl alcohol, the mixing ratio of polyvinyl alcohol and polyvinyl chloride, the content of boric acid or the molecular orientation and crystallization of the fibers and im In the case of fibers with a higher degree of flame resistance, the content of SnO ₁ or tin (Tv> acid can be observed. This can be seen from Table II above, which shows how the properties of the fibers change with changes in the various manufacturing conditions Test procedures used here and in the examples are described in the footnote.

The invention will now be explained in more detail by the following examples:

example 1

H ₃ BO ₃ was added to polyvinyl alcohol having a degree of polymerization of 1700 and a degree of saponification of 97.8 mole percent, and the mixture was dissolved in water at 10O ⁰ C to form an aqueous solution containing 16.2% polyvinyl alcohol and 1.5% , based on polyvinyl alcohol, of H ₃ BO ₃ . The solution was cooled to 60 ⁰ C. A poly vinyl chloride emulsion with an average particle diameter of 200 Å and a pH of 7, the obtained by emulsion polymerization of vinyl chloride using sodium aautyl sulfate as an emulsifier was made with the above solution mixed, the PVA / PVC weight ratio and the total polymer concentration, as indicated in table ΙΠ, vary. The mixture was allowed 1 day at 6O ⁰ C stand for defoaming it. The spinning solution was placed in a coagulating bath

ao, which contained 50 g / l sodium hydroxide and 160 g / l sodium sulfate. The threads were spun stretched to 2 times the original length using rollers, then neutralized and in moist heat at a stretch ratio of 2

as stretches. The stretched threads were au! a residual content of H ₈ BO ₃ of 0.1%, based on the weight of polyvinyl alcohol, washed. The threads were passed through a bath that was 400 g /! Na ₁ contained SO ₄ to act on the threads of Glauber's salt spend, and then dried. The dry threads were in dry heat at 228 ° C stretched at a stretch ratio of 3 and shrunk 10% at 231 ° C in a dry state Obtain threads with a monofilament denier of 2 denier The total draw ratio was 12. The Eigen shafts of the threads that were subsequently heat treated were measured and the results are ii Table III reproduced.

Table ΙΠ

Attempt no.

Conditions of manufacture

Polymer-PVA / PVC concentration (V.)

Degree of saponification (Mole percent)

Properties of the threads

strength (g / den)

Water-

durability

CO

Lightfastness

Flame retardancy (degree)

1 2 3

85:15 75:25 65:35

15.7 16.5 18.6

more than 99.9 more than 99.9 more than 99.9 9.2 8.1 6.8

118 118 117

96 92 83

3 3 3

It is based on the results shown in table ΠΙ it is apparent that, according to the method of the invention, the Vetseflang fully advances and the sublime Fibers have excellent strength, water resistance, moisture resistance and retardation. The spinning state was for 5 days well, the method of the invention was found to be excellent in terms of workability.

Example 2

Η, ΒΟ, 2a became polyvinyl alcohol with a degree of poly of 1700 or a degree of saponification of 97.5% are added and the mixture is entered into water at HXTC to form an aqueous solution mixed which had 16.2% polyvinyl alcohol and 2.5%, b based on the weight of the polyvinyl alcohol, a Η, ΒΟ. The solution was heated to 50 ⁰ C geküM A Polyvinylchloridemalsion with a mean TeSchendarchmesser of 500 Å, by the emulsion:

Polymerization of vinyl chloride in Gege να polyvinyl alcohol was obtained, the above aqueous solution at 50 ° C with a PV / PVC ratio of 80:20 and a Pol; added mereakoettion of 16.4%. Man Ik the mixture was at 50 ° C for the day to defoam!

The spinning solution was in a Rour bath, ds

10 g / l Nstrixmihydroxid and 350 g / l Nt contained, "sposnen. The spun fidea became

13 14

to twice the original length by means of rollers. The spinning condition was quite good for 10 days and showed

stretches, in moist heat at a ratio of 2, superior workability.
stretched in a saturated Glauber's salt bath at 65 ^{° C}

and washed with water until the remaining HsBO ₃ - Example 4
Content reached 0.15% based on polyvinyl alcohol. 5

The threads were then immersed in an aqueous solution of polyvinyl alcohol with a degree of polymerization which contained 6 g / l Tire Cord Oil No. 2010 and dried at 1700 and a degree of saponification of 99.1 mol. The filaments were in the dry state percent borax and nitric acid (to adjust at a stretch ratio of 3 at 23O ⁰ C stretched pH to 4.5) were added to an aqueous dispersants and then to 10% in a dry heat at 235 ° C ge ίο sion of tin (IV) acid and Sb ₁ O ₃ with a medium shrink. The total draw ratio was 12, and particle size of 0.8 microns added and among the obtained fibers had a monofilament denier of heating dissolved. The solution was heated to 5O ⁰ C gevon 1.5 denier, a saponification degree of 99.9%, a supercooled. A polyvinyl chloride emulsion with a mitt strength of 8.9 g / den and a Heißwasserbestän- sized particle diameter of 500 A, the sionspolymerisation by Emuldigkeit of 118 ⁰ C. The light stability of the fibers 15 in the presence of vinyl chloride was 93%, and the degree dei Flame retardancy obtained from polyvinyl alcohol was 3. Thus, all properties of strength, of the above solution were mixed, with PVA / PVC hot water resistance, light resistance and weight ratio being 65:35, polymer concentration being superior to flame retardancy of filaments, and 17 .8%, the stannic acid content 0.3%, based on the spinning state, was good for 5 days. The properties of the polymer (calculated as SnO,) and the Sb _t O ₃ content were stable. 1%, based on the polymer, and the borax content Example 3 ² > ⁵ %> based on polyvinyl alcohol. the

obtained spinning solution was allowed to develop for 1 day

Polyvinyl alcohol with a degree of polymerization foam.

of 1750 and a saponification degree of 98.5% and 25 The spinning solution was introduced into a coagulating bath ge-H ₃ BO ₃ were spönnen to an aqueous dispersion of SnO _8, 15 g / l of sodium hydroxide and 350 g / l Namit an average particle size of Contained 1.2 microns of trium sulfate. The spun threads were given and dissolved therein with heating. The solution to twice the original length by rolling was cooled to 6O ⁰ C and stretched with a polyvinyl, neutralized and in moist heat in a chloride emulsion with an average particle diameter 30 saturated Glauber's salt bath at 68 ⁰ C with a knife of 200 A and a pH value of 6.9, the stretching ratio of 2. The stretched filaments by emulsion polymerization of vinyl chloride were _{diluted with water to a remaining H 3} BO ₃ using an emulsifier from Emal, content of 0.22%, based on polyvinyl alcohol. No. 0, which was washed by a 0.05 g / l sodium hydroxide and contained sodium lauryl sulfate as the main ingredient, was mixed. The bath containing 300 g / l sodium sulfate was passed and the weight ratio of polyvinyl alcohol to polyvinyl was then dried. The filaments were then in dry chloride was 75:25, the total polymer concentration at 235 ° C with a draw ratio was 16.5%, the SnO ₁ content was 2 Ge of 3.1 and stretched around 10% in dry State by weight, based on the polymers, and that at 235 ° C has shrunk. Threads with an H ₃ BO ₃ content of 1.8 percent by weight, based on 40 monofilament denier of 2.5 denier, were obtained. These threads on polyvinyl alcohol. The dope was allowed had MoI to stand for 1 day at 6O ⁰ C a PVA degree of hydrolysis of 99.96. percent, a hot water resistance of '117 ⁰ C,

The spinning solution was placed in a coagulating bath to a strength of 7.1 g / den, a light resistance

The 60 g / l sodium hydroxide and 160 g / l Na- of 75% and a flame retardancy of grade 3. contained trium sulfate. The threads spun became 45

to twice the original length using rollers
stretches, neutralizes and in moist warmth for you

Stretch ratio of 2 stretched. The same spinning solution as in Example 3 was _{spun with water to a residual H 3} BO ₃ content of 0.1 Ge in a coagulating bath containing 40 g / l sodium percent by weight, drawn on polyvinyl alcohol, 50 hydroxide and 250% by weight contained g / l sodium sulfate. Those seen passed through a bath containing 300 g / l sodium spoaneaen filaments were twice the original suffate to apply the salt to the filaments, stretched length using rollers, and dried. The threads were then neutralized at one and then either (1) in a moist draw ratio of 3 at 229 ° C in dry heat at a draw ratio of 2 ^ was stretched and at 10% in the dry state 55 washed with water and applied one shrunk at 233 ^C C The threads obtained had salt solution subjected to the threads or (2) not a degree of saponification of 99.95 mol percent, a water washed, the application of a salt solution PVA / PVC ratio of 75/25, iron SnO _t - Attack on the threads subjected to the weakened state of 2%, based on the polymer, and a content at a draw ratio of 2J. stretched Then at Η, ΒΟ, of 0.1%, based on polyvinyl alcohol, 60 was the same drying, stretching in and a monoradeatiter of 2 den. The total dry tub (with the exception of the stretching ratio) and the shrinkage treatment as in Example 3

Dw properties of the threads obtained have been carried out in. The properties of the thread obtained

in the same manner as indicated in tables, and the amount of washout of H ₃ BO _{1 was} measured. The threads were found to measure a 65. The results are shown in Table IV.

Hot water resistance of 116 ^e C, given a strength. The total stretching ratio shows a mtaa-

vtw 7.8g / den, a lightfastness of 78% and times the ratio of the pieces according to the procedure O)

Graduated from Grade 3. The or (2) manufactured threads.

Table IV

v «-
travel Total-
stretching
ver
ratio Washout
extent of
Η, ΒΟ,
(m) * Firm
speed
(g / den) Hot water
resistant
speed
( ⁰ Q (1)
(2) 12th
13.5 40
22nd 8.0
7.4 115
114

*) The required length of a wash bath to reduce the remaining HaBOj content to 0.11%, based on polyvinyl alcohol, to belittle.

From the results obtained, it can be seen that in the case of using the method (1), the length of the washing bath had to be large, but the threads obtained had high strength, while in the case of the Method (2) the length of the washing bath can be short, although the strength of the threads obtained something is low.

Example 6

Polyvinyl alcohol having a degree of polymerization of 1750 and a degree of saponification of 98.5 mol percent and H ₃ BO ₃ were added to an aqueous dispersion containing SnO ₂ having an average particle diameter of 2 microns and a known flame retardant, and dissolved therein with heating. The solution was cooled to 60 ⁰ C. A polyvinyl chloride emulsion with an average particle diameter of 250 ⁰ C and a pH of 6.9, which was obtained by emulsion polymerization of vinyl chloride using an emulsifier containing sodium lauryl sulfate as the main component, was with the above solution to form a spinning solution with a PVA / PVC weight ratio of 70:30, a total _{polymer concentration of 17.3%, an SnO 2} content of 0.5%, based on the polymer, a content of the known flame retardant of

ίο 1.3%, based on the polymer, and an H ₃ BO ₃ content of 2.0%, based on the polyvinyl alcohol, mixed. The spinning solution was allowed to stand for 12 hours to defoam.

The spinning solution was spun in a coagulating bath, which contained 120 g / l sodium carbonate and 180 g / l sodium sulfate. The spun threads were stretched to twice the original slope using rollers, neutralized, in a damp place Heat at a stretch ratio of 2 in one

ao stretched saturated Glaubersalzbad at 68 ⁰ C and washed with water to a remaining H ₃ BO ₃ content of 0.08%, based on polyvinyl alcohol. The yarns were then immersed in an aqueous solution containing 6 g / l Tire Cord Oil Nr. 2010 included, dried, stretched in dry condition at 230 ⁰ C at a draw ratio of 3 and shrunk by 10% at 235 ° C. The total draw ratio was 12. The obtained filaments had a monofilament denier of 1.8, a PVA saponification degree of 99.95 mol%, a hot water resistance of 117 ° C., a strength of 7.6 g / denier, a light resistance of 82% and a Grade 3 flame retardancy.

Claims (2)

Extensive flame retardation through aftertreatment Claims: S eSen, it is necessary to 1. To use flame-retardant fibers from a fermentation agent in large quantities, whereby Mixture of polyvinyl alcohol and polyvinyl chloride, which affects the properties of the fibers which also contains other additives, thereby becoming 5; in addition, the flame retardancy is marked, that the polykung fibers have recently been degraded by washing vinyl alcohol developed with a medium polymerization spinning process in which a degree of flame Spinning solution containing from 500 to 3000 and a degree of saponification retardant is used of at least 99.5 mole percent polyvinyl chloride becomes heavy to the direct spun fibers themselves and boric acid and optionally tin (IV) oxide to make it flammable. However, there were none or stannous acid, the results being satisfactory, Weight ratio of polyvinyl alcohol to poly- It is well known that polyvinyl chloride (PVC) has good properties vinyl chloride is 90:10 to 55:45, the content of flame retardant properties. However turn out to be of boric acid 0.02 to 0.5 percent by weight, based on fibers produced from this polymer on the weight of the polyvinyl alcohol, and if there is 15 reason of poor strength and heat resistance, the content of the tin compound 0.1 to the speed of this polymer for practical use 5 percent by weight, based on the total weight, is not considered satisfactory. To eliminate this of the polymers, whereby the fibers were generally made from a mixture of fibers, with the disadvantage of Rieh The fiber axes are molecularly oriented and polyvinyl chloride and polyvinyl alcohol (PVA) are predominant Beat water resistance of at least 100 ° C ao. However, since the polyvinyl alcohol is flammable exhibit. is, the fibers thus obtained are decreased 2. Process for the production of flame retardant, and if also the polyflammable Fibers made from a mixture of polyvinyl alcohol after the formation of the fibers not acetavinyl alcohol and polyvinyl chloride, which will lize still others, is the water resistance of the fibers and additives contains, characterized in that as sufficient. Another disadvantage of the fibers from one a partially saponified polyvinyl alcohol with a mixture of polyvinyl chloride and polyvinyl alcohol average degree of polymerization of 500 to 3000 is that they have a poor lightfast and a degree of saponification of 88.5 to 99.5 molar mass, although the two polymers at percent, 0.5 to 4 percent by weight, based on separate use, requires good lightfastness Shrewd! of polyvinyl alcohol, boric acid 30 sit. The usual polyvinyl chloride-polyvinyl alcohol and possibly a tin compound with a fiber therefore always proved to be unsatisfactory, mean particle size of not more than 20 microliters from Japanese Patent Laid-Open No. 7,128,219 crown made of tin (IV) oxide and / or tin (IV) - a manufacturing process for flame-retardant PVA-PVC acid consists, are dissolved in water, the preserved fibers indicated, their flame retardancy by tene aqueous dispersion with an emulsion of 35 added specific amounts of antimony compound polyvinyl chloride is achieved with a medium particle fertilization. The resulting PVA-PVC diameter of not more than 1000 Å among fibers, however, have insufficient strength Formation of a spinning solution is mixed, with and light resistance. In addition, they are there the weight ratio of polyvinyl alcohol to available fibers to achieve a sufficient Polyvinyl chloride 90:10 to 55:45 and the content 40 formalized hot water resistance. of the tin compound, if present, 0.1 to 5 Ge. Furthermore, in Belgian patent specification 759 394 weight percent, based on the total weight of the (according to the German Offenlegungsschrift Polymers, the spinning solution obtained in 2 055 320) is a method for improving the strength alkaline coagulating bath with formation of speed and the initial modulus of a PVA fiber Gel threads is spun, the gel threads between 45 the addition of boric acid or a borate to a Rolling stretched, then re-coagulating in a saiaren bath, in which the fibers are spun and rebalanced and stretched it again in moist warmth. In this publication, however, is the threads before or after the second do not indicate any fire resistance of the fibers Stretch washed with water until the contained. Residual boric acid content 0.02 to 0.5 wt reached, the threads are dried, the struggles with regard to flame retardant fibers. So Dried filaments in dry worms must have fibers that are suitable for use by the inferior Stretching up to a total position of industrial material, for example of aspect ratio of at least 10 and then tents, a high degree of flame retardancy be subjected to a shrink treatment. 55 in addition to sufficient strength and lightfastness own. So far, however, there have been no fibers which have been found to be satisfactory with regard to these requirements.