DE2019803A1 - Acrylic composite fiber and process for making them - Google Patents

Description

D.pi. Ing.H.?ini Usser. l \ >. ·· ■ -. «» v _a , t D-8M, · ϊ - '· Co'.imaslrafc · 81 · Telephone: (0811) 48'38.20

Mitsubishi Rayon Company Limited L 9087

Tokyo (Japan) April 23, 1970

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Acrylic composite fiber and process for its manufacture

The invention relates to an acrylic composite fiber and method for their production.

Compared to other synthetic fibers, the conventional ones Acrylic fibers and the textile goods made from them are better in terms of their grip, colorability and durability or strength. They are, however, in thermosetting, in dimensional ones Inferior in stability, wrinkle resistance and hot-wet properties. There is a desire to overcome such Disadvantages of acrylic fibers.

Acrylic composite fibers have properties similar to wool fibers. From these, however, the conventional acrylic composite fibers differ mainly in that wool fibers are the inner ones The crimp component is stiffer than its outer component, while in conventional acrylic composite fibers, both the outer component as well as the inner component are more pliable and in particular the inner component of the crimps compared to the outer Component thereof is even more pliable in a further degree.

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Thus, in the prior art acrylic composite fibers outer and inner components, in other words, a low Young's initial modulus, the modulus being the inner Component is lower than that of the outer component, namely at a temperature above their glass transition temperatures The conventional acrylic composite fibers are consequently inferior to wool fibers in the stability of their crimp.

With the foregoing in mind, the invention has set itself the goal of creating an acrylic composite fiber, which in particular in their thermosetting, in their dimensional Stability, in their hot-wet properties, in their pilling effect and in their grip is better than the conventional acrylic single or composite fibers. Looking for such an acrylic fiber the invention has specifically made use of the knowledge that in order to achieve these properties it appears necessary to use the two To give components a high Young's modulus, with improvement of the hot-wet properties components with a hydrophobic behavior should be chosen and these components in their Side-by-side arrangement must have an improved affinity for one another. The composite fiber should also be in its molecular The structure should be sufficiently oriented, and this orientation should be stronger than can usually be achieved with a pulling process.

The desired properties is now being leaves the invention with a two-component acrylic Verbundkräuselfaser achieve, in which the one component selected from polyacrylonitrile and the other component aua an acrylonitrile-Methakrylnitrii copolymer consists, daa between 5 and 50 wt.% MethakrylnitrU entbgl £ which Polyacrylonitrile component is attached to the outer side of the Krausefeagesi. Dis

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Attempts leading to the invention thus initially had the result that a polyacrylonitrile fiber has the highest Youn g modulus. On the other hand, it was found that an acrylonitrile-methacrylonitrile copolymer has almost the same properties as polyacrylonitrile. In particular, it has been found that methacrylonitrile is a Comonomer is compared to a decrystallization monomer According to the definition given below, it has different properties; as such a decrystallization monomer occurs for example vinyl acetate and methyl methacrylate into consideration. Methacrylonitrile does not reduce the crystallinity of the resulting acrylonitrile copolymera in its case to a decisive extent Incorporation by means of copolymerization, it forms mixed crystals, which can be viewed as paracrystals and a two-dimensional one Have a structure with acrylonitrile units.

The invention is now to be followed in its further features and advantages are described in more detail with reference to the drawing.

Ee show:

Figure 1 X-ray graphs of polyacrylonitrile

and of acrylonitrile-methacrylonitrile copolymers,

Figure 2 X-ray graphs of polyacrylonitrile

and of acrylonitrile-vinyl acetate copolymers,

3 shows the temperature dependency in a diagram

the vibration module E 'and the vibration «- loss module E "of polyacrylonitrile and of acrylonitrile-methakrylonitrile Miechpoiymeren,

4 shows the temperature dependency in a diagram

of the tangent of the oscillation loss · of

'1098 S1 / U22

D pi -Ing. Heinz Lester. P · ϊ 1 >r'ian «a! t D - 8 MunA'in b !. Cosimaitraf} 81 Telephone: (0811) 48 38 20
~ 4 - Polyacrylonitrile and acrylonitrile methacrylic nitrile copolymers, and Fig. 5 the temperature dependence in a graph of the vibration module E 'and the vibration loss modules E "of polyacrylonitrile and of Acrylonitrile-vinyl acetate copolymers,

From Fig. 1 it can be clearly seen that the degree of crystallinity of the copolymer is not significantly reduced with increasing methacrylonitrile content, which can be attributed to that methacrylonitrile, hereinafter referred to as MAN for short, with acrylonitrile units Forms mixed crystals. This becomes particularly clear via a comparison with the illustration according to FIG. 2. The Fig. 2 indicates that a higher level of vinyl acetate subsequently briefly referred to as VAC, in which the mixed polymer results in an extreme drop in the crystallinity, and that the paracrystalline structure is completely converted into an amorphous structure if the VAC content exceeds the value of 20% by weight. A such a monomer is referred to in this description as a "decrystallization comonomer" designated. Under a decrystallization monomer, for example, vinyl acetate, acrylic acid, methyl acrylate, Methacrylic acid, methyl methacrylate, acrylamide, methacrylamide, vinyl pyrrolidone, etc. can be understood. The conventional acrylic fibers now usually consist of an acrylonitrile copolymer that contains one of these decrystallization comonomers.

The methacrylonitrile-acrylonitrile copolymers are now particularly notable in their dynamic or oscillation flow behavior. In this context, FIG. 3 shows the temperature

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dependence of the vibration module E 'and the vibration loss module E "of acrylonitrile-methacrylonitrile copolymers, in particular that of a copolymer which contains 12.5% by weight MAN contains, which content essentially corresponds to that of polyacrylonitrile, hereinafter referred to as PAN for short. As Furthermore, Fig. 4 shows, with regard to the tangent of the vibration loss for the copolymer, there is an absorption peak; which is at a lower temperature than that of PAN. These properties of the acrylonitrile-methacrylonitrile copolymer are mainly due to the behavior of the methacrylonitrile unit returned in the copolymer, it can be assumed that, as mentioned above, this unit mixed crystals with Acrylonitrile forms and that the methacrylonitrile unit is higher Glass transition temperature, which finds its way into the polyacrylonitrile crystals, thereby retarding the molecular movement of the acrylonitrile polymer chain. From Fig. 5 is now further it can be deduced that the vibration modulus E 'and the vibration loss module E "of a decrystallization monomer containing Acrylonitrile copolymer drops abruptly when the amount of decrystallization monomer in the copolymer is increased.

From the foregoing it should be seen that the acrylonitrile-methacrylonitrile copolymer behaves completely differently As the acrylonitrile copolymer containing a decrystallization monomer, FIG. 13 shows its properties are similar to those of FIG Polyacrylonitrile.

Taking into account the aforementioned knowledge is now after the main feature of the invention is a two-part acrylic composite crimped fiber characterized by the existence of one

1Q9851 / U22

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Component made of polyacrylonitrile and, by virtue of the fact that the other component consists of an acrylonitrile-methacrylonitrile copolymer, the methacrylonitrile being contained in this copolymer in an amount between 5 and 50% by weight, in particular between 7 and 30% by weight, and where the polyacrylonitrile component is attached to the outside of the crimps. Such a composite fiber can now be means of a conjugated extruding two spinning masses produced, from which the one of polyacrylonitrile and the other of acrylonitrile Methakrylnitril copolymer with 5 to 50 wt -%, or 7 to 30 wt - consists% Methakrylnitril.. together through one and the same mouth of a spinneret in a dry process. The composite fibers are thus obtained in a very simple manner, which are then subsequently drawn and finally relaxed. Before relaxing, the drawn fibers can be mechanically crimped.

Special design features of the invention provide for the polyacrylonitrile to give a specific viscosity between 0.12 and 0.28, preferably between 0.15 and 0.23. These dimensions the viscosity is determined by a measurement in dimethyl formamide at a concentration of 0.1 at 25 ° C. Such a solution Polyacrylonitrile can be made in the conventional manner will. For the acrylonitrile-methacrylonitrile copolymer it has already been stated above that it is preferably between 5 and % By weight, in particular between 7 and 30% by weight, methacrylonitrile should contain. Both polyacrylonitrile as well as acrylonitrile-methacryl-! nitrile copolymers can contain small amounts of other comonomers, in particular in amounts between 0, 3 and 6% by weight

2 / -AIe comonomers in question can here 'vinylpyridine,

109851 / U22

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2-methyl-5-vinylpyridine, vinylbenzenesulfonic acid and sodium methallyleulfonate can be considered in order to improve the dyeability of the fibers, for example. The monomer unit should preferably be either a strong acid group Contain salt or free acid,

Polyacrylonitrile and the acrylonitrile-methacrylonitrile copolymer are separately dissolved in a suitable solvent and then conjugated extruded through the opening of a spinneret in order to achieve the To form composite fibers. The composite fibers can be either one Side-by-side arrangement of the two components or it can have one component as the core in the other component be included as a coat. The following aspects should be taken into account for the spinning process and for the aftertreatment will.

The two types of spinning lakes are created by means of a dry one Spinning process conjugated to form the composite fiber, which is then drawn in a hot water bath and finally dried, whereupon a heat treatment in relaxed State follows so as to cause a curl. The preferred solvents for preparing the spinning masses are dimethylformamide, dimethylazetamite, dimethyl sulfoxide, »Y-butyrolactone, hexamethylene phosphoramide, etc. use. The drawn, wet fiber can also be crimped mechanically before crimps develop as a result of the aforementioned heat treatment in the relaxed state. So lets the shape of the crimps modulate, the heat treatment following drying increasing the stability that leads to ripples. Alternatively, it can also be provided

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that on the formation of crimps, the fibers are then uncrimped and then processed into a fabric that
is then subjected to a heat treatment again, so that the
To let ripples arise again. You then receive a commodity
which is characterized by a special grip.

It is also possible to use the dried composite fibers under elongation j

stress, for example, of the order of 10 mg / d j

to subject them to steam heating and then j

to crimp mechanically, whereupon the composite fibers to staple j

ι fibers are cut and spun into yarns to produce ι

Manufacture of finished or semi-finished yarns. These will

then, in a relaxed state, a heat treatment under - I thrown to create crimps.

The crimp of the composite fiber of the invention is dimensionally '■

more stable than that of conventional acrylic fibers. This is mainly due to the fact that the fiber is composed of the polyacrylonitrile, which crystallizes very well, and the acrylonitrile-methacrylonitrile copolymer, and that these two polymer components
have a very high Young's modulus. The crimp of the composite fiber according to the invention is dimensionally very stable even under hot-wet conditions, which is due to the fact that the methacrylic!

nitrile unit of the composite fiber a better hydrophobic behavior ι

shows as the acrylonitrile unit.

109851 / U22

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- 9 - example 1

There were polyacrylonitrile in dimethylformamide, a 93% by weight |

Copolymer containing acrylonitrile and 7% by weight vinyl acetate, and j

an 87.5% by weight acrylonitrile and 12.5% by weight methacrylonitrile j containing copolymer dissolved separately so as to three kinds of

Obtain spinning masses. The spinning dope containing polyacrylonitrile;

possesses a specific viscosity of the polymer of 0.22 and a '·.

Concentration of the polymer of 24%, the closest spinning mass

had a specific viscosity of the polymer of 0.169 and a \

Concentration of the polymer of 29 % and the last spinning mass!

finally had a specific viscosity of 0.171 and a '

Concentration of 29%. The specific viscosity was each

in a dimethylformamide solution with a concentration of 0.1:

measured at 25 C.

i The first and third dope were then conjugated extruded

through the opening of a spinneret in a conventional manner to

thereby obtaining a composite fiber. The following prevailed:

Conditions before: extrusion temperature 120 C, opening diameter

0.15 mm, number of openings in the spinneret 50, temperature

of the heated air 180 C, flow velocity of the air '.

1 m / sec. and winding speed 300 m / min. The received ^,;

undrawn composite fiber contained 23.8% by weight dimethylformamide. .

They were then reduced to four times their original length in one

Bath drawn with boiling water and finally dried to

so to get a fixed length for the fiber. The composite fiber

was then in the relaxed state superheated steam of 3.0 kg / cm

Exposed to pressure.

109851/1422

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For comparison, a composite fiber was spun similarly from the first and second spinning masses, and it was found that, in terms of the crimp property, a crimp rigidity of 2.1 g / d and a crimp stability of 86% could be achieved in one case in the comparison case values of 1.3 g / d or 64 % were obtained. In this context, "rigidity of crimps" is understood to mean the minimum elongation, under which a crimp has its property of developing back again after the elongation. By "crimp stability" in this context is meant the crimp persistence expressed by the following equation.

^ _{lQQ (%)}
5% crimp '''

For both the 1% and the 5% crimp, the Values from the last reading are used, based on standards as set out in the JIS 1-1074 standard.

In the example described here, the component was polyacrylonitrile attached to the outside of the crimps.

Example 2

Polyacrylonitrile with a specific viscosity of 0.19 was used in Dissolved dimethylformamide in order to obtain a spinning mass in which the polymer was present in a concentration of 24% by weight. on the other hand became a 70 wt.% acrylonitrile and 30 wt.% methacrylonitrile containing copolymer with a specific viscosity of 0.175 dissolved in dimethylformamide in order to obtain a further spinning mill, in which the polymer was present in a concentration of 29% by weight.

109851/1422

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These two spinning masses were then conjugated and extruded through the openings of a spinneret under the conditions of the example The undrawn composite fiber was then stretched to four times its original length in a water bath at a temperature of 95 ° C, at the same time the remaining solvent was extracted. The drawn composite fiber was then placed on heated rollers dried and finally in a relaxed state by means of superheated steam of 2.0 kg / cm pressure heat nimble It to a crimp to build. The crimp stiffness and crimp stability the final fiber was 2.2 g / d or 88%. For comparison, let stated here that with the conventional acrylic composite fibers for the crimp stiffness values between 1.2 and 1.3 g / d and for the crimp stability values between 60 and 64% can be achieved so that it can be concluded that the acrylic composite fiber of the present invention is far from the conventional composite fiber is superior.

Example 3

A 92 wt -. ⁰ J ₀ acrylonitrile and 8 wt -.% Methakrylnitril-containing copolymer having a specific viscosity of 0, 170 was dissolved in dimethylamide, to obtain a spinning mass in which the polymer in a concentration of 29 wt - existed%. . This spinning mass was then conjugated with the first spinning mass of Example 1, a specific viscosity of 0.22 and a concentration of the polymer of 24%, under the conditions of Example 1. The undrawn composite fibers were then twice their original length in one Bath stretched with boiling water. The composite fiber was then dried,

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a length shrinkage of 10% was found. the The composite fiber was then steamed under a tensile load of 10 mg / denier to make it nimble so as to be crimped to obtain. When treated in a relaxed state in the bath with boiling water, the development of pimples could develop The curl stiffness was measured to be about 1.8 g / d.

Example 4

An 8 5 wt -.% Acrylonitrile and 15 wt -.% Methakrylnitril-containing copolymer having a specific viscosity of 0, 168 was dissolved in dimethylformamide to obtain a spinning mass in which the polymer in a concentration of 29 wt - existed%. . This spinning mass was extruded conjugate together with the first spinning mass of Example 1, namely under the conditions of Example 1, it being assumed that both spinning masses contained a strong acid group, which in the spinning mass of this example was in a concentration of 5, 6 χ 10 ^{e <} ? / G and for the first spinning mass of Example 1 in a concentration of

- 5th
2.7x10 eq / g was present. The composite fiber was then stretched to five times its original length in boiling water and then dried on heated rollers; after drying, the composite fiber was immersed in boiling water at a stretch rate of 15 mg / denier. This was followed by cutting into staple fibers, and these staple fibers were then spun into a yarn which was ultimately made into a fabric. The fabric was treated in boiling water in a relaxed state to ^ q K | ä "Succeeded to entwiche In _r was fixed

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put that the fabric has a very good grip and, in particular, greatly improved dimensional stability distinguished, it should be noted in particular that the fabric could not be discharged, as is the case with fabrics made from the conventional acrylic composite fibers.

Example 5

The unstretched composite fiber of Example 4 was applied to the Stretched twice their original length in hot water and then dried on heated rollers; subsequently became the composite fiber then immersed in boiling water in a relaxed state to create ripples. The resulting composite fiber possessed a crimp stiffness of 1.7 g / d, which is the comparative value of conventional acrylic composite fibers is further superior.

The crimped composite fibers were then 1, 15 times stretched their original length at a temperature of 70 C for de-crimping and then cut into staple fibers, which in turn become a Spun yarn and finally made into a fabric. The fabric was subjected to steam treatment in the relaxed state so that puckers developed. The mesh was characterized in particular by a dimensional stability and a favorable grip.

109B51 / U22

D'pl.-Ing. Heini Leisc-i, Ur -la

D - 8 Munich ^for Coslmosttofee B] · Telephone: (Fri..i) 48 332ß

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Example 6

A 86 wt -.% Acrylonitrile, 13 wt -.% Methacrylonitrile and 1 wt -.% Natriumvinylbenzolsulfon-containing copolymer having a specific viscosity of 0.172 was dissolved in dimethylformamide to obtain a spinning mass in which DA6 polymer in a concentration of 29, 5 wt -.% was present. This spinning mass was then extruded conjugate with the first spinning mass of Example 1, also here under the conditions of Example 1. The unstretched composite fiber was then stretched to four times its original length in hot water and finally dried; a pressure of 1.8 kg / cm heat treated in a relaxed state to develop puckers. The crimp stiffness of the resulting composite fiber was 2.2 g / d.

The crimped composite fiber was then adjusted to 1. IT times its original length stretched at a temperature of 70 C to de-curl it, followed by mechanical curling, cutting into staple fibers, spinning into a yarn and finally processing into a fabric. The fabric was treated with steam, to develop ripples on it. The resulting tissue was puffy, had good grip, and especially excellent dimensional stability.

Example 7

A 99% by weight acrylonitrile and 1% by weight sodium methallyisulfonate containing copolymer with a specific viscosity of 0.189 was dissolved in dimethylformamide to obtain a spider mole,

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Dip! -Ing. Heinz Usser, Pol.-n'ar.walt D - 8 Münzen 81, Cosimasttojje 81 Telephone: (0811) 483820

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at which the polymer in a concentration of 24 wt -.% was present. On the other hand, a copolymer containing 90% by weight of acrylonitrile and 10% by weight of methacrylonitrile and having a specific viscosity of 0.167 was dissolved in dimethylformamide to obtain a further spinning dimension in which the polymer was at a concentration of "29.5% by weight These two spinning masses were then conjugated extruded under the conditions of Example 1, the unstretched composite fiber was stretched to four times its original length and finally dried. The dried composite fiber was subjected to steam at a pressure of 2.5 kg / cm , in the relaxed state, in order to obtain crimps, which were characterized by a very high stability and uniformity.

1 0 9.8 5 1 /. U 2 2

Claims (3)

Dr-; NS . ι Uv-! ·; ..;> D - 8 mm -: · .- ■! rA (. · .. ..'-- ilio 81 · Telephone: (0811) 48 38 20 - 16 - PATENT CLAIMS 1. Two-component acrylic composite crimped fiber, one component of which is made of polyacrylonitrile and the other component of! consists of an acrylonitrile-methacrylonitrile copolymer which contains between 5 and 50% by weight , in particular between 7 and 30% by weight , of methacrylonitrile, the polyacrylonitrile component being attached to the outside of the crimps. 2. Two-component acrylic composite curls according to claim 1, i characterized in that at least one; of the two components between 0.3 and 6% by weight of one Contains a monomer unit that contains a strong acid group either as a salt or as a free acid. 3. Process for making a two-part acrylic composite crimped fiber according to claim 1 or 2, characterized in that the two components are conjugated by the Opening of a spinneret as spinning masses extruded in a manner known per se as part of a dry spinning process and the composite fiber obtained is then stretched and finally relaxed, optionally before this relaxation mechanical crimping is made. ■ 109851 / U22 Blank page