DE2313205B2 - Flame retardant fibers and processes for their manufacture - Google Patents

Description

The invention relates to flame-retardant _ISs made from a mixture of polyvinyl alcohol and vinyl chloride which also contains other additives, and to a process for their production.
Many methods have heretofore been proposed, 11 a flame retardant for adhering to or reacting with synthetic fibers

bring them and make them flame retardant or Lier-resistant. Some of these ways of working are technically applied. However, to get an out-mixture of P? ¹ ^! ^ ¹ ^ ™

then insists that she is one

ability, although Je

separate use

sit «The usual ^^^

Fibers have therefore proven to be steady

From the Japanese outlook. ".

a manufacturing process for permanent PVA PVC. Fibers indicated their nammfestigkeit ^e ^ t ^d urch ZusaU of specific quantities, is erre.cht to Ant.monverb.ndüngen. The dabe. obtained PVA-P \ C. However, fibers have a Jf »" «* ^^^" and light resistance. In addition, the fibers available there to achieve sufficient hot water resistance formally. ^s ' ^ert .

In the Belgian PaUns Further, "759 394 (corresponding to the German OBelegung" writing 2,055,320) a process for ^v? *? 5JJ _«F ^F Jl? G resistance and the initial modulus einerJ'VA fiber by the addition of boric acid or a Bo * ts for a coagulating bath, in which the fibers are spun, described. In this publication, however, there is no indication of the fire resistance of the fibers. A _{nfrir /} i »

Ir recent years various f fl rften m s ^ e Fa A s "i ° rd s e" wrestled with regard to hard ^ """^^ f ^ f V.?. 0 must be fibers that are suitable for use in the manufacture of industrial materials. for example tents, have a high degree of flame retardancy in addition to sufficient strength and resistance. To date, however, there have not been any fibers which have been found to be satisfactory with regard to these requirements.

The object of the invention is to create flame retardant fibers made from a mixture of polyvinyl alcohol and polyvinyl chloride with superior Flame resistance and light resistance the can be produced at low cost and not the disadvantages of the known polyvinyl alcohol. Have polyvinyl chloride fibers.

According to the invention are difficult to flam Fibers made from a mixture of polyvinyl alcohol and polyvinyl chloride containing 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 (IV oxide or tin (IV acid), the weight ratio being 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 on the total weight of the polymers is, 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 alcohols 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 tin (IV) acid, are 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 greatly 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 not acetalized, the fibers according to the invention have been stretched to a high degree are, due to the boric acid contained therein, sufficient water resistance without acetalization exhibit. It is believed that this is due to the fact that when containing boric acid 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 threads with a homogeneous one Cross-sectional area can be obtained and that the gel threads by the subsequent dehydration the threads at a higher ratio to form threads with a homogeneous structure practically circular cross-section can be stretched.

Since the fibers according to the invention do not have to be acetalized, the reduction in flame resistance can 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 tin (IV) oxide and tin (IV) acid

effective flame retardants for polyvinyl alcohol-polyvinyl chloride fibers are.

It has heretofore been known that antimony trioxide (Sb ₂ 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 ₂ ) has a synergistic effect with polyvinyl chloride. However, the latter has hardly been used because it is inferior to or at most equivalent to antimony oxide in terms of flame retardancy, and it is also very expensive. Attempts have been made to produce flame-retardant polyvinyl alcohol-polyvinyl chloride fibers by adding a tin salt of a strong acid to an acetalizing bath for the fibers with the incorporation of tin (IV) acid into the fibers (DT-OS 2 029 734). As will be shown later in detail, although the flame resistance of the fibers is improved, their strength and, in particular, light resistance are deteriorated. For example, films were made from a mixture of a polyvinyl alcohol-polyvinyl chloride polymer composition with stannous oxide, stannous acid or antimony trioxide, and the flame retardancy properties of each film were determined in terms of LOI values (limiting oxygen index) according to ASTM method D-2863-70). The results are given in Table I.

Table I.

Amount of additives (%)

Sb ₂ O ₃

SnO ₂

Stannous acid ....

Polymer

Polyvinyl
chloride

2
36

35.5

36.5

Polyvinyl
alcohol

2
19.6

19.5

19.5

PVA / PVC ratio

75/25

27
31

32.5

67/33

5 6

As can be seen from Table I, SnO ₁ , or to a greater extent, SnO ₄ or tin (IV) -tin (IV) acid have a far greater flame retardant acid in an amount of 0.1 to 5 percent by weight the polyvinyl alcohol-polyvinyl chloride- based on the polymer in the fibers, evenly system as Sb ₄ O ₃ . This was an unexpected result. dispersed.

It is believed that this result is based on 5 The stannic acid is preferred /? - stannic acid. When the amount of the tin compound is less than just polyvinyl alcohol-polyvinyl chloride is 0.1% by weight, the flame retardant or those consisting of antimony trioxide as the flame retardancy of the fibers is not satisfactorily mediated containing polyvinyl alcohol-polyvinyl improved, and if the amount of 5 percent by weight consist of nyl chloride, burned, decompose it exceeds io, the properties of the fibers, as in the heat with melting. On the other hand, strength, for example, deteriorates. Thus, if fibers made from polyvinyl alcohol-polyvinyl amounts outside the specified range, host chloride containing SnO ₂ or tin (IV) acid are economically disadvantageous and undesirable.
As stated above, the fibers should be used to set fire

Melting, however, immediately before melting 15, a high degree of strength is achieved and the polymer is hardened and infusible with sufficient water resistance both in moist and high temperatures, and its carbonization heat as well as fully stretched in dry heat is promoted. It appears that polyvinyl alcohol becomes and is subjected to a shrink treatment plays an important role in the curing reaction of the polymer, whereby the fibers are molecularly oriented. Further, it is believed that the polyvinyl chloride ao 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 that of water, and the hydrogen chloride gas with SnO ₂ or resistance of at least 11G ° C attains tin (IV) -acid with the formation of a tin chloride is rea-.

In order to prevent the burning process in the manufacture of the fibers according to the invention

Fibers is effective. Thus, the polyvinyl as is eoric acid to partially saponified polyvinyl alcohol alcohol-polyvinyl chloride-SnOj- or tin (IV) -acid- added, and the mixture is in water at 90 Masses have a particularly good flame retardancy up to 130 ° C. The solution is effective at 40 to 75 ° C exhibit. cools and with an aqueous emulsion of polyvinyl

In order to obtain fibers with high strength, the chloride should be mixed and then the polyvinyl alcohol should be defoamed at 40 to 75 ° C. with a medium polymerization temperature to achieve a spinning solution. The degrees of 500 to 3000, and in order to obtain a high ^{spinning solution maintained at 40 to 75 D} C in a water resistance, the polyvinyl bath should be spun, the alkaline dehydration alcohol contains a degree of saponification of at least 99.5. After various treatments, own inclusion mole percent. The inclusion of polyvinyl lent roll stretching, neutralization, moist heat; chloride is essential for achieving flame-retardant stretching and washing with water, the threads like fibers. The weight ratio of poly- dried, pulled in dry heat and vinyl alcohol to polyvinyl chloride should be 90:10 to shrink. If necessary, the threads can be after 55:45. In the case of smaller amounts of polyvinyl the rinsing stage with an aqueous solution of salt chloride of a lower value given 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 chlorinated but can also be a copolymer made of turned polyvinyl alcohol, preferably one in the middle 75 mole percent vinyl chloride with an external degree of polymerisation of 500 to 3000. If their comonomers and a grafted vinyl chloride - the average degree of polymerization less than 500 be-copolymer, Grafted onto the polyvinyl alcohol, it is impossible to obtain fibers of high strength has been (keeping the ratio of grafted 50, and if it is over 3000, the visco-Pr Lyvinyl alcohol usually no more than 5 molar content of the spinning solution at the 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, alcohols are 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. application 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 ° 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 tem-

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 lower temperatures, however, polyvinyl 15 The spinning solution thus formed is then converted into an alcohol-polyvinyl chloride fibers Spun by poor hot coagulating bath, in which instant water resistance supplies, used, which borrowed during the gelation of the threads and subsequent entdes Spinning process take place by using an alka-watering of the same. For example, is Nali Coagulating bath is completely saponified, using trium carbonate alone or a mixture of alkali Use of a high draw ratio to produce hydroxide or sodium carbonate with Glauber's salt 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 ₃ BO ₃ ) can be produced by any water-soluble alcohol and can be a boric acid salt with sufficient coagulability, and the amount is present. 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 % , although it does not sufficiently gel depending on the degree of saponification of the, and if the polyvinyl alcohol used varies. If it is less than 4%, the gelation is too violent, and if it becomes 30 5 g / l, saponification of the polyvinyl brittle gel filaments proceeds, which leads to processing alcohol not sufficiently proceeding, and gelation of the stanchions. 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 that does less than soaping of the polyvinyl alcohol.

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

The threads are not preferred because of their poor dyeability

admitted. 45 water washed until the remaining boric acid echo

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

Have particle size of not more than 1000 Å. weight of the polyvinyl alcohol. 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 echo

Fiber is low. 50 is less than 0.02 "", the extensibility of the threads becomes

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

temperature of 75 ^C C or above and polyvinyl to maintain hot water resistance. If he owes

alcohol at a temperature of 30 ^c C or below 0.5%, the fibers obtained are not 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 emulsion 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 bad, and if it is over 45 "·" far from boric acid should be sufficient resentment. An

the toughness of the fibers is reduced. On the other hand, if 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 fibers, the fibers

when polyvinyl chloride in a larger amount ent- washed with water in a loose state, and there

than in the case of the manufacture of polyvinyl, the fibers are well swollen. In this case came

Chloride-Polyvinylalkohol-Iasern according to the usual length of the wash bath be large, but are di

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 _{3 are dissolved} in an aqueous dispersion of pulverulent SnO ₂ with heating, and the solution is cooled ^{to 30 to 80 ° C.} The solution is then ver with an aqueous emulsion of polyvinyl chloride

mixes and the mixture is defoamed to obtain a spinning solution. The spinning solution is in a alkaline coagulating bath, and then the threads are spun in the same manner as above with reference to aul describes the process for making fibers from polyvinyl alcohol, polyvinyl chloride and boric acid various treatments including roller stretching, neutralization, stretching in moist eggs Heat, washing with water, drying, stretching in

ίο subject to dry heat and shrinkage.

The powdery SnO ₂ or the stannous acid is easily 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.

ze meren low, and the flame retardancy effect is reduced.

Optionally, other flame retardants such as Sb ₂ O _{3 in} addition to SnO _: or stannic acid can be used.

Table II

Poly-
merisa-
functional
degree of
Polyvinyl
alcohol Composition of the fibers PVA /
PVC
Ver
ratio SnO,
(° / o) be
pulled
on the
Poly
meren H ₃ BO,
(Vo) be
pulled
on PVA DFA
• 2 Total-
stretching
ver
ratio
♦ 2 Properties of the fibers Hot-
water-
persistent
age
* 3
CC) Firm
speed
(g / den) light
persist
age
• 4
% Flame
ver
hesitated
hesitation
• 5
(Degree) attempt
No. 1750 Ver
soapy
Degree
(Mol
percent) 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 99.9 75/25 1 0.18 - 10 112 3.1 87 3 3 1750 99.9 75/25 1 0.12 - 11 103 6.8 85 3 4th 1750 99.2 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 - 11 109 6.2 91 3 8th 1750 99.9 75/25 1 0.15 - 9.2 108 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 11 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, ^ 30th 2 14th 1750 99.9 59/41 (1.2)
• 7 0 * 6 32 7th 121 2.4 25th 2 15th 99.9

• 1 DFA: Degree of formalization of the fibers that have been heat treated and then acctylated with formaldehyde (mole percent

based on polyvinyl alcohol). '

• 2 total stretching ratios, with the exception of tests 9, 11, 12 and 15, the total stretching ratios given are 90 ° /

the laxinal piece diameter to which the threads could be drawn without breaking. Thus, these values show in essence

bark the extensibility of the thread. • 3 hot water resistance: the threads were immersed in water while weighing 1/500 a / den of the threads

underwent. The immersed threads were heated to an extent of 2'C per minute, and the temperature at de the thread

. "FSSJ ^ Ψ ^ * ^ Τΐϋ. ,, ^ TaU? * ¹ '£ "" £. ⁸⁶ T ^{8611 The} temperature indicates the hot water resistance • 4 Light resistance: The ratio of the remaining strength of the threads after the threads had been exposed for 100 hours with a Fade O-Meter of type FA-I.

• 5 Ftomnwerzögenmg: threads with a total denier of 1800 denier were twisted to an extent of 90 turns ie meters

and knitted into a cloth having a unit weight of 20 g / m 2 using a knitting machine. The knitted Tucl was evaluated according to the method described in m nS-L-1091 A1. Grade 3 is sufficient and Grade 1 m is not sufficient

• 6 The spinning solution contained no H ₁ BO ,, and the spun threads were dehydrated using a Glauber's salt bath

and coagulates.

• 7 The spinning solution contained ksine H ₁ BO, and the spun threads were dewatered and coagulated using a Clauhera bath. The obtained filaments were heat-treated and treated with an acetalizing bath. the tin tetrachloride contained in order to detail the threads and at the same time air treatment of tin (IV) acid treated

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 acetalizing the obtained filaments.

(2) The fine particles of SnO ₂ 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, strength and light resistance.

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

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 ₂ or stannous acid must be complied with. This can be seen from Table II above, which shows how the properties of the fibers change with changes in the various manufacturing conditions. The 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:

¹ 12

example 1

H ₃ BO ₃ was added to polyvinyl alcohol with a degree of polymerization of 1700 and a degree of saponification of 97.8 mol percent, and the mixture was dissolved in water at 100 ^° 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 polyvinyl chloride emulsion having an average particle diameter of 200 Å and a pH of 7, which was obtained by emulsion polymerization of vinyl chloride using sodium autyl sulfate as an emulsifier, was mixed with the above solution, the PVA / PVC weight ratio and the total polymer concentration such as given in Table III, vary. The mixture was left to stand at 60 ° C. for 1 day to defoam it.
The spinning solution was blown into a coagulating bath containing 50 g / l sodium hydroxide and 160 g / l sodium sulfate. The spun filaments were drawn to 2 times the original length using rollers, then neutralized and drawn in moist heat at a draw ratio of 2. The drawn threads were washed with water to a residual H ₃ BO ₃ content of 0.1%, based on the weight of polyvinyl alcohol. The threads were passed through a bath containing 400 g / 1 Na ₂ SO _{1 in} order to apply Glauber's salt to the threads, and then dried. The dry fibers were be in dry heat at 228 ⁰ C at a draw ratio of 3 and 10% stretched be 231 ° C in the dry state shrunk. The yarns with a monofilament denier of 2 denier were obtained. The total draw ratio was 12. The properties of the yarns, which were then heat-treated, were measured and the results are shown in Table III.

Table III

Manufacturing conditions polymer
concentration
("/") Degree of saponification
(Mole percent) strength
(g / den) Properties of the threads light
resistance Flame ver
hesitation
(Degree) Try Ni. PVA / PVC 15.7 more than 99.9 9.2 water
resistance
( ⁰ Q 96 3 1 85:15 16.5 more than 99.9 8.1 118 92 3 2 75:25 18.6 more than 99.9 6.8 118 83 3 3 65:35 117

From the results shown in Table HI, it can be seen that, according to the method of the invention, the Saponification progresses completely and the fibers obtained have excellent strength, hot water resistance, Have light resistance and flame retardancy. The spinning state was for 5 days good, and the method of the invention was found to be excellent in terms of workability.

Example 2

H ₃ BO ₈ was added to polyvinyl alcohol having a PoIymerisationsgrad of 1700 and a saponification degree of 97.5%, and the mixture was mixed in water at 100 ⁰ C to form an aqueous solution containing 16.2% polyvinyl alcohol and 2.5% , b based on the weight of the polyvinyl alcohols, ι H ₃ BO ₃ had. The solution was heated to 50 ⁰ C gekühl A polyvinyl chloride emulsion having an average TeiJchendurchmesser of 500 A, the polymerization by emulsion of vinyl chloride in the presence vt polyvinyl alcohol was obtained, was added to d above aqueous solution at 5O ⁰ C with a PV / PVC-weight ratio of 80:20 and a polymer concentration of 16.4% was added. The mixture was left to defoam at 50 ° C. for 1 day

10 g / l sodium hydroxide and 350 g / l sodium sulphate contained, vei fun. The spun threads were

23 13 205 υ

13 14

ψ 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.
| i stretched in a saturated Glauber's salt bath at 65 ° C

S. and washed with water until the remaining H ₃ BO ₃ - Example 4

Content reached 0.15% based on polyvinyl alcohol. 5

fc The threads were then placed in an aqueous solution of a polyvinyl alcohol having a degree of polymerization

dipped, which contained 6 g / l Tire Cord Oil No. 2010 and of 1700 and a degree of saponification of 99.1 mol

k dried. The threads were dried percent borax and nitric acid (to adjust the

at a stretching ratio of 3 at 230 ^c C stretched pH value to 4.5) were to an aqueous dispersion

and then by 10% in dry heat at 235 ^C C ίο sion of tin (IV) acid and Sb ₂ O ₃ with an average

shrinks. The total draw ratio was 12. and particle size of 0.8 microns added and under

\ the fibers obtained had a monofilament of heating dissolved. The solution was on 50 ⁰ C

ί of 1.5 den, a degree of saponification of 99.9%, one cools. A polyvinyl chloride emulsion with a medium

\ Strength of 8.9 g / denier and a hot water resistant particle diameter of 500 Å, which is

temperature of 118 ° C. The light resistance of the fibers 15 sion polymerization of vinyl chloride in the presence

; was 93%, and the degree of flame retardancy obtained from polyvinyl alcohol * ar was made with

j 3. Thus, all properties of the strength of the above solution were mixed, with the PVA / PVC-

Hot water resistance, light resistance and weight ratio 65:35, the polymer concentration

The flame retardancy of the threads is superior, and the 17.8%, based on the stannous acid content 0.3%

Spinning condition was good for 5 days. The properties of the polymer (calculated as SnO ₂ ), the Sb ₂ O ₃ content

\ were stable. 1%, based on the polymer, and the borax content

• B e i s ρ i e 1 3 were 2.5%, based on polyvinyl alcohol. the

; obtained spinning solution was allowed to develop for 1 day

j Polyvinyl alcohol with a degree of polymerisation will foam.

j of 1750 and a degree of saponification of 98.5% and 25 The spinning solution was placed in a coagulating bath

H3BO3 were spönnen to an aqueous dispersion of SnO ₂ , the 15 g / l sodium hydroxide and 350 g / l Na-

with an average particle size of 1.2 microns contained sodium sulfate. The threads that were spun

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 one

chloride emulsion with an average particle diameter of 3 ° saturated Glauber's salt bath at 68 ° C at a

knife of 200 Å and a pH of 6.9, the stretching ratio of 2 stretched. The stretched ones

by emulsion polymerization of vinyl chloride threads were with water on a remaining H ₃ BO ₃ -

using an emulsifier from Emal content of 0.22%, based on polyvinyl alcohol, g * -

No. 0, the sodium lauryl sulfate as the main ingredient, wash through a 0.05 g / l sodium hydroxide and

contained, had been obtained, mixed. The bath containing 300 g / l sodium sulphate is carried out unci

weight ratio of polyvinyl alcohol to polyvinyl then dried. The threads were then dried in

chloride was 75:25, the total polymer con? "- nem state at 235 ⁰ C with a stretching ratio

Tration was 16.5%, the content of SnO ₂ was 2 Ge of 3.1 stretched and around 10% in the dry state

weight percent, based on the polymer, and that shrunk at 235 ° C. There were threads with one

The H ₃ BO ₃ content was 1.8 percent by weight, based on 40 monofilament titers of 2.5 denier obtained. These threads

on polyvinyl alcohol. The spinning solution obtained had a PVA saponification degree of 99.96 mol

one day at 6O ⁰ C stand. percent, a hot water resistance of 117 ^C C

The spinning solution was placed in a coagulating bath with a strength of 7.1 g / den, a light-resistant wedge

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 threads were The same spinning solution was used as in the example:

spun with water to a residual H ₃ BO ₃ content of 0.1 Ge in a coagulating bath, the 40 g / l sodium

percent by weight, drawn on polyvinyl alcohol, contained 50 hydroxide and 250 g of sodium sulfate. The GE

see, passed through a bath, the 300 g / l sodium spun filaments were twice the origin

containing sulfate to apply the salt to the filaments, lent length stretched using rollers

and dried. The threads were then neutralized at one and then either (1) in moist

Stretching ratio of 3 at 229 ^° C. in dry add-on heat at a stretching ratio of 2.2

stood stretched and washed by 10% in the dry state 55 with water and applying one

shrunk at 233 ° C. The threads obtained possessed saline solution on the threads or (2) mi

a degree of saponification of 99.95 mole percent, a water washer., the application of a salt solution

PVA / PVC ratio of 75/25, subjected to a SnO ₂ content on the threads and in a moist state

of 2%, based on the polymer, and a content at a draw ratio of 2.2 stretched. Danacl

of H, BO _S of 0.1%, based on polyvinyl alcohol, 60 the same drying, stretching ii

and a monofilament denier of 2 den. The total dry heat (with the exception of the stretch ratio

stretching ratio was 12. nisses) and the shrink treatment as in the example

The properties of the threads obtained were carried out in The properties of the filaments obtained were measured in the same manner as shown in Table II, and the amount of washout of the H ₃ BO ₈ was measured. The threads were found to measure a 65. The results are given in Table FV as the hot water resistance of 116 ° C, a strength. The total stretching ratio shows a maxi

of 7.8 g / den, a light resistance of 78% and times the stretching ratio of the after VerM-en (1st possessed a degree 3 flan delay. The or (2) manufactured threads.

η
f
t
t

Table IV

Vsi-
travel Total-
stretching
ver
ratio Washout
wet des
Η, ΒΟ,
(m) · Firm
speed
(B / den) Hot water
resistant
speed
( ⁰ C) (1)
(2) 12th
13.5 40
22nd 8.0
7.4 115
114

*) The required length of a wash bath to the remaining Η, ΒΟ, 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 SnOg having an average particle diameter of 2 microns and a known flame retardant, and dissolved therein with heating. The solution was cooled ^{to 60 ° C.} A polyvinyl chloride emulsion having an average TeiJchendurchmesser of 250 ⁰ C and a pH of 6.9, which contained by emulsion polymerization of vinyl chloride using an emulsifier, sodium lauryl sulfate as the main component, was obtained, was charged with the above solution to form a spinning solution with a PVA / PVC weight ratio νση 70:30, a total polymer concentration of 17.3%, a SnO ₂ -GeImIt 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 into a coagulating bath containing 120 g / l sodium carbonate and 180 g / l sodium sulfate. The spun threads were stretched to twice the original length using rollers, neutralized, stretched in moist heat at a stretching ratio of 2 in a saturated Glauber's saline / bath at 68 "C and with water to a remaining H ₃ BO ₃ content of 0 The threads were then immersed in an aqueous solution containing 6 g / l Tire Cord Oil No. 2010, dried, stretched in the dry state at 230 ° C. at a stretching ratio of 3 and um Shrunk 10% at 235 ^° C. The total draw ratio was 12. The threads obtained had a monofilament liter of 1.8, a degree of PVA saponification of 99.95 mol.

zciit, a hot water resistance of 117'C, a Strength of 7.6 g / dcn, a light resistance of S2% and a flame retardation of grade 3.

Claims (1)

Patent claims: 1. Flame retardant fibers made from a mixture of polyvinyl alcohol and polyvinyl chlorides which also contain other additives, thereby geke η η ζ calibrated η et that the fibers made 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 (IV) oxide χα or tin (IV) acid, the weight ratio of polyvinyl alcohol to polyvinyl chloride being 90:10 to 55:45 and the boric acid content 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 polymers, the fibers being molecularly onentiated in the direction of the fiber axes and a hot water resistance of at least 100 ° C _M ^ Process for the production of flame-retardant fibers from a mixture of polyvinyl alcohol and polyvinyl chloride, which still contains other additives contains etching substances / characterized in that * ₅ 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 mol percent, 0.5 to 4 percent by weight, based on the weight of the Polyvinyl alcohol, boric acid and optionally a tin compound with a mutated particle size of not more than 20 microns, which consists of tin (IV) oxide and / or tin (IV) acid, are dissolved in water, the resulting aqueous dispersion with an emulsion of polyvinyl chloride having 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 being 90:10 to 55:45 and the content of the tin compound, if any, 0.1 to 5 weight percent , based on the total weight of the polymers, the resulting spinning solution is spun in an alkaline coagulating bath to form gel threads, the gel threads between hen rollers are stretched, then neutralized in an acidic bath and stretched again in moist heat, the threads are washed with water before or after the second stretching until the residual boric acid content reaches 0.02 to 0.5 percent by weight Threads are dried, the dried threads are subjected to a continuous stretching in dry heat up to a total stretching ratio of at least 10 and then a shrink treatment. sufficient flame retardation through aftertreatment ™ «, it is necessary to use the flame retardation to CUCIi-", Jj _{61st quantity} , whereby ™ ^η ^ ^η | ^ _Γη own properties affect the rase -m _B ^ _d ^ pjammverzögerungswir- «* ™ λ · ^^ _aadiea diminished. Recently kung «W ™ ^^ ^ j _dem a flame *? '! j ™ dope-containing dope - uses delay ^ tt « _{mn fibers se} ,, ^^ will be around the ™ ° £ * J _{E but} ^^ _no gii «received. Polyvinyl chloride (PVC) good quality. However, sera produced fibers prove to be strength and heat resistant. ^ g _ktische use elimination of this mixture from Sr ^ tia ^ u (PVA) vorgeder polyvinyl alcohol flammable ^^^^^ enen fibers have a reduced flame resistance and - - poly viny alcohol after J ^^ JJ ^ K ^ lized, is that Reason
ability this
not as