JPH01236210A - Acrylonitrile polymer - Google Patents

Abstract

PURPOSE:To make it possible to melt mold an acrylonitrile polymer and improve the gas barrier properties, by specifying the acrylonitrile content, the reduced viscosity and the content of acetone solubles. CONSTITUTION:70wt.% or more acrylonitrile and 30wt.% or less copolymerizable monomer having a glass transition point of -60-+30 deg.C (e.g., methyl acrylate) are subjected to suspension polymerization in the presence of an emulsifier, a polymerization initiator and a molecular weight modifier (e.g., n-lauryl mercaptan), thereby producing an acrylonitrile polymer which has a reduced viscosity of 0.2-1.0 and a content of acetone solubles of 5-20%, and wherein when acetone solubles (X) and acetone insolubles (Y) are separated, Y accounts for 50wt.% or more of the acrylonitrile content and the reduced viscosity is 0.05-0.2. The resulting polymer is heated to 160-230 deg.C to be melted and molded at a speed of 500-5,000m/min to obtain fiber or film.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for producing fibers useful for clothing and decoration, and a film useful as a gas barrier film.
This invention relates to a novel acrylonitrile polymer.

[Conventional technology]

2) Acrylonitrile polymers undergo heat treatment.
Since the cyclization reaction of the lJz group occurs and the product becomes infusible, it is impossible to mold by the melt molding method, so a wet molding method with a complicated manufacturing process is inevitably adopted. however,
Attempts to melt-shape such acrylonitrile polymers are known from U.S. Patent No. 2,412,034, Japanese Patent Publication No. 52-2007, etc.; A cyclization reaction of the nitrile group occurs,
It has been pointed out that it becomes infusible and also becomes colored. Another method is to coordinate a small amount of water to an acrylonitrile polymer and use water as a plasticizer to form fibers (% table No. 55-501061, Japanese Patent Publication No. 59-47725, Japanese Patent Publication No. 59-13Q15) JP-A-50-111148) and acrylonitrile-based polymers and acrylonitrile dimer or trimer compositions for melt molding (JP-A-50-111148).
Publication No.) etc. have been disclosed.

[Problem to be solved by the invention]

The above-mentioned method of using water as a plasticizer involves discharging the water-coordinated acrylonitrile polymer from a spinning nozzle under heating and pressure.
Even if humidity control conditions are strictly regulated, it is difficult to prevent the formation of voids due to water volatilization in the acrylonitrile polymer composition after shaping.

Furthermore, the method disclosed in JP-A No. 50-111148 requires a step of washing and removing acrylonitrile dimers (b and trimers) after spinning, and simplifies the steps specific to melting and shaping. This is not achieved.

Although methods have been proposed to produce Y fibers by melt spinning, which are inferior to fibers obtained by wet spinning or dry spinning, no satisfactory method has yet been developed. The current situation is that this is not the case.

In view of the current state of production of acrylonitrile fibers produced by the above-mentioned melt-spinning method, the present inventors have made extensive studies and found that by using an acrylonitrile polymer with a specific composition, it is easy to produce fibers without using plasticizers such as water. The inventors have discovered that acrylonitrile fibers can be produced using the method, and have completed the present invention.

[Means to solve the problem]

The gist of the present invention is an acrylonitrile polymer containing 70% by weight or more of acrylonitrile, which has a reduced viscosity of α
2 to 1.0 and containing an acetone soluble component of 5 to 20% by weight.

The acrylonitrile polymer of the present invention has a reduced viscosity of 12
~1.0 polymer is required. If the reduced viscosity is less than 112, the melt-forming properties may not be good, or the mechanical strength of the resulting fibers may not be sufficient for use as fibers or films.
The ill value is small. On the other hand, if the reduced viscosity exceeds to, the polymer will not melt and cannot be melt-shaped.

The acrylonitrile polymer of the present invention must contain 5 to 20% by weight of an acetone-soluble component; if the acetone-soluble component is less than 5% by weight, the acrylonitrile polymer will not melt, so It cannot be melt-shaped.

Moreover, if it exceeds 20% by weight, although the melt-forming property becomes good, the heat resistance of the resulting FIi fibers and films decreases significantly, making it impossible to obtain a practical melt-forming product.

The acrylonitrile polymer of the present invention has not only heat-melting properties but also fluidity and spinnability, which are important factors when shaping into fibers or films. The reason why the polymer exhibits such fluidity and stringability is that the acetone-soluble low molecular weight polymer contained in the acrylonitrile polymer of the present invention acts as a plasticizer. In order for this acetone-soluble component to act as a plasticizer, it is desirable that its composition be within the AM50 weight range and have a reduced viscosity of α05 to (1L2). If the molecular weight deviates from this range, it is undesirable because the physical properties of the obtained fiber will deteriorate, and the melt-shaped product obtained by shaping such a polymer is
Due to its low physical properties, it can only be used for special purposes.
.

Furthermore, a major feature of the acrylonitrile-based polymerization of the present invention is that it can be made into fibers by melt-forming, but in general, in melt spinning, the spinning speed cannot be significantly increased compared to the wet spinning method. It is possible, and productivity can be greatly improved by performing high-speed spinning.

Therefore, in order to improve the spinning speed, the quality of the spinnability when the polymer used is melted is an important factor, but in order to further improve the spinnability, the present invention When the acrylonitrile 4-based polymer is divided into an acetone-insoluble component α) and an acetone-soluble component (Y), (Y) contains acrylonitrile in an amount of 70 to 90% by weight, and the reduced viscosity is 3 to α8.
It is an acrylonitrile-based polymer in which (Y) contains acrylonitrile in the range of 68 to 88 weight percent, the reduced viscosity Q is 05 to 0.2, and the acrylonitrile in (Y) and (Yl) is The relationship between the contents is shown in Figure 1A,
It is preferable that it is within the range of B and O, and furthermore (
Y) has an acrylonitrile content of 84 to 88% by weight and a reduced viscosity (L4 to 0.6), (Y) has an acrylonitrile content of 74 to 86% by weight and a reduced viscosity of [LO5 to 0.2]
and (Xri, acryloni in (X) and (Y))
The relationship between the content of IJ A/ is A/ in Figure 1.

More preferably, it is within the ranges of B', C', and D'.

By incorporating such an acrylonitrile polymer, melt spinning at a spinning speed of 3000 m/min or more becomes possible.

In order to obtain the polymer of the present invention, if the polymerization is carried out to a polymerization rate of 90% or more, a polymer with a relatively high molecular weight will be produced because the monomer concentration is high in the early stage of the polymerization, but the polymerization rate in the late stage of the polymerization will be particularly high. When the temperature exceeds 1, the concentration of chloride decreases to a level of -10 compared to the initial stage of polymerization. The acrylonitrile polymer produced under such conditions inevitably has a low molecular weight. When producing the acrylonitrile-based polymer of the present invention, by carrying out the polymerization at a polymerization rate of 9 (Y% or more), a low molecular weight polymer that becomes a plasticizer can be appropriately contained in the polymer. Therefore, in order to obtain an acryloni-IJN polymer with good melt-forming properties, it is preferable to carry out the polymerization at a polymerization rate of 90 or more.

On the other hand, in producing the acrylonitrile-based polymer of the present invention, other weight substances to be copolymerized with acrylonitrile are:
The glass transition temperature (Tg) of the monomer is -60°C to +30°C
Seven polymers that can be copolymerized in the range of ℃ (Tg=3℃), ethyl acrylate (']'
g=-22℃), n-propyl acrylate (Tg=-
44°C), n-butyl acrylate (Tg=-56°C)
, n-hexyl methacrylate (Tg=-5°C), n-
octyl methacrylate) (Tg=-20℃), vinyl acetate (Tg=29℃), vinylidene chloride (Tg=-1
7° C.) is preferred, but monomers copolymerizable with acrylonitrile, such as acrylic acid, methacrylic acid, itaconic acid, hydroxyalkyl alkylate or methacrylate, acrylamide, methacrylamide, etc., are generally mentioned. It is possible to copolymerize these polymerizable unsaturated monomers alone or in combination.

Furthermore, if the copolymerization amount of acrylonitrile contained in the acrylonitrile-based polymer of the present invention is larger than a predetermined range, the melt-forming property will be decreased, while if the copolymerization amount is small, the melt-forming property will be lowered. The physical properties of objects deteriorate.

For copolymerization with these monomers, known methods can be applied, but from the point of view of the homogeneity of the resulting polymer, emulsion polymerization is preferred, and the emulsifier used in the b0 emulsion polymerization method may be any known emulsifier. For example, fatty acid salts, alkyl sulfate ester salts, alkylbenzene sulfonates,
Anionic surfactants such as alkyl phosphate ester salts and dialkyl sulfosuccinates, or nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, and glycerin fatty acid esters can be used. can.

As the polymerization initiator, a common water-soluble inorganic initiator such as persulfate can be used alone, or it can be used as a redox initiator in combination with sulfite, bisulfite, thiosulfate, etc. Furthermore, organic hydroperoxide ferrous salts, organic hydroperoxide sodium salts, redox initiators such as formaldehyde sulfoxylate, and azo compounds can also be used.

In order to control the reduced viscosity of the obtained polymer within the range of the present invention, K is n-lauryl mercaptan, t
This can be achieved by adding a molecular weight regulator consisting of mercaptans such as -dodecyl mercaptan and n-octyl mercaptan, and adjusting the amount added.

The polymer thus obtained contained 55% of the acetone-soluble component.
B, which contains up to 20% by weight, is in the form of a powder, and B is supplied in the form of pellets to a hot-melt extruder, where it is heated and melted and shaped. A method for shaping such an acrylonitrile polymer will be explained below using fiber as an example.

The heating and melting temperature for fiber shaping is 160 to 230°C.
A range of is preferred. If the heating melting temperature is less than 160°C, the polymer will not melt sufficiently to form fibers, while if it exceeds 230°C, the polymer will be markedly colored, which is not preferred. The polymer melted in the extruder is discharged through a spinning nozzle to form an undrawn yarn, which can then be drawn and heat-set to form a fiber. In this case, the spinning speed is 500~
It is possible to set it as 5000m/min. Furthermore, when shaping into a film, it is possible to form a film by a method similar to that used for fibers.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples. In addition,
In the text, "parts" indicate parts by weight.

The breaking strength and breaking elongation were measured using a Tensilon type testing machine at a sample length of 20 m and a tensile speed of 20 m/min.

The weight ratio of acrylonitrile (AN) and methyl acrylate (MA) in the obtained polymer was calculated based on the elemental analysis value of the polymer.

Reduced viscosity is polymer α5t dimethylformamide 100
This is a value measured at 325°C after dissolving 11tK.

Example 1 In a polymerization vessel equipped with a nitrogen introduction tube, a cooling tube, and a metering pump, 2000 parts by weight of distilled water adjusted to pH 4 with sulfuric acid, 20 parts by weight of sodium laurylbenzenesulfonate, and 9 parts by weight of lauri V mercaptan as a molecular weight regulator. After charging 170 parts by weight of acrylonitrile and 30 parts by weight of methyl acrylate and raising the temperature to 45°C, 1 part by weight of potassium persulfate and 1 part by weight of ammonium bisulfite were added, followed by 680 parts by weight of acrylonitrile and 120 parts by weight of methyl acrylate. 15 parts of a mixed solution of 36 parts by weight of laurylmetal butane
After 0 minutes of addition, the polymerization was further carried out at the same temperature for 60 minutes, and then the temperature of the polymerization system was raised to 60° C., and the polymerization was continued for 60 minutes to complete the polymerization. The obtained polymerized latex was coagulated according to a conventional method, dehydrated, washed, and then dried at 60°C. The polymerization rate was 99%, and the mu N/MA was 85/15.

The thus obtained powdered acryloni) IJA/
A system polymer (reduced viscosity α45) was supplied to a screw-type heating melt extruder, melted at 215°C, discharged from a nozzle using a metering pump, and spun at a spinning speed of 600 m/min to obtain an undrawn yarn. was stretched twice on a hot plate at 170°C, and relaxed by 20 inches in hot air at 150°C.

The strength of the obtained acrylic fiber is 1.9? /d, elongation 2 (Y
It was 1 liter.

Comparative Example 1 The Ac 1.1 ronitrile polymer obtained in Example 1 was washed with acetone. As a result, 11% by weight of the acetone soluble content was removed. Acetone soluble content is A N /
MA, 80/20, reduced viscosity (L14, acetone insoluble matter was AN/MA).

85/15. Reduced viscosity (Y49). When spinning was attempted in the same manner as in Example 1, spinning was impossible due to insufficient melting. When the heating melting temperature was raised to 230°C, it became 0 and completely Although it could be melted and spun, the resulting fiber was significantly colored.

Example 2 The polymers shown in Table 1 were obtained in the same manner as in Example 1, except that the weight ratio of acrylonitrile/methyl acrylate (AN/MA) and the amount of mercaptan added were changed, and the polymers were spun in the same manner as in Example 1. When the spinnability was examined, the results shown in Table 1 were obtained.

Example 3 The polymers shown in Table 2 were obtained in the same manner as in Example 1, except that the polymerization rate was changed, and the polymers shown in Table 2 were spun in the same manner as in Example 1 to examine the spinnability, and the force results shown in Table 2 were obtained. Ta.

Table 2 Example 4 Using the acrylonitrile N-based polymer obtained in Example 1, it was melted at 215° C. and extruded through a T-die to produce a planar film with a thickness of 10 μm.

The obtained film had practically sufficient physical properties.

Example 5 Polymers shown in Table 3 were obtained in the same manner as in Example 1 by changing the A N / IJ A composition ratio and the amount of lauryl mercaptan added, and were spun in the same manner as in Example 1 to determine spinnability (spinning properties). speed).

Table 3 [Effects of the Invention] The acrylonitrile polymer of the present invention can be easily melt-shaped, and therefore, compared to the wet-type molding method, the acrylonitrile polymer can be easily melt-formed using the Daifuku simplified molding method. It is possible to shape a 1-based polymer. Furthermore, the acrylonitrile fiber obtained by melt-shaping the acrylonitrile polymer of the present invention has a unique texture and luster, and has a curling characteristic compared to conventional acrylonitrile N-based polymers.

Furthermore, when shaped into a film, it is very useful as an oxygen barrier film.

Claims (1)

[Scope of Claims] 1. An acrylonitrile polymer containing 70% by weight or more of acrylonitrile, which has a reduced viscosity of 0.1 to 1.
0 and the acetone soluble content is 5 to 20% by weight.
A melt-formable acrylonitrile polymer comprising: 2. Acetone insoluble content (X) of acrylonitrile polymer
When separated into acetone soluble content (Y), (Y) has an acrylonitrile content of 50% by weight or more and a reduced viscosity of 0.0.
5. The polymer according to claim 1, which has a molecular weight of 5 to 0.2. 3. (X) is acrylonitrile content 70-90% by weight, reduced viscosity 0.3-0.8 (Y) is acrylonitrile content 68-88% by weight, reduced viscosity 0.05-0.2
Claim 1, wherein the relationship between the acrylonitrile contents in (X) and (Y) is within the ranges A, B, and C in Figure 1.
Polymers described. 4, (X) has an acrylonitrile content of 84-88% by weight and a reduced viscosity of 0.4-0.6; (Y) has an acrylonitrile content of 74-86% by weight and a reduced viscosity of 0.05-0.
6. The polymer according to claim 5, wherein the relationship between the acrylonitrile contents in (X) and (Y) is within the ranges A', B', C', and D' in FIG.