JPS5930803B2 - Acrylic synthetic fiber with excellent flame retardancy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an acrylic synthetic fiber that has good dyeability and excellent flame retardancy.

Specifically, the present invention provides an acrylic polymer with good dyeability and enhanced flame retardancy, which is made of an acrylonitrile polymer mainly composed of acrylonitrile, vinyl chloride, and/or vinylidene chloride, and finely divided zinc oxalate, zinc phosphate, or zinc borate. It concerns synthetic fibers.

It is well known that among acrylic synthetic fibers, those containing relatively high amounts of vinyl chloride and/or vinylidene chloride maintain the texture of acrylic fibers, but are far superior in flame retardancy to acrylic fibers. .

In addition, social demands for flame retardancy are becoming increasingly sophisticated, and in order to meet this demand, the present inventors have been studying additives that have a large flame retardant effect even when added in small amounts.

Many additives are known to improve flame retardancy, but among these, there are some that are effective when added in small amounts to acrylic synthetic fibers, but also have practical problems such as dyeability. There are few things without it.

For example, zinc compounds such as zinc oxide and zinc carbonate are also known, but these zinc compounds are effective in improving the flame retardance of acrylic synthetic fibers when added in small amounts, but they cannot be dyed with cationic dyes. In this case, the dye changes color, making it difficult to use practically.

Therefore, as a result of intensive studies to solve the problem of dye discoloration, the present inventors found that among zinc compounds, especially zinc oxalate, zinc phosphate, and zinc borate, when added in small amounts, flame retardancy was achieved without impairing dyeing properties. The inventors have discovered that it is possible to obtain acrylic synthetic fibers with excellent properties and have arrived at the present invention.

That is, the present invention uses 20 to 80% by weight of acrylonitrile.
and vinyl chloride and/or vinylidene chloride 80-20% by weight
An acrylic synthetic fiber made by adding 0.4 to 20% by weight of zinc oxalate, zinc phosphate, and zinc borate to an acrylonitrile polymer consisting of be.

The acrylonitrile polymer used in the present invention is composed of 20 to 80% by weight of acrylonitrile and 80 to 20% by weight of vinyl chloride and/or vinylidene chloride, and an olefinic monomer that can be copolymerized with these is copolymerized. However, I can't stand all of you.

However, if the acrylonitrile content is 80% by weight or more, it is very difficult to strengthen the flame retardancy, and if the acrylonitrile content is less than 20% by weight, it lacks the properties as an acrylic synthetic fiber.

Here, the olefinic monomer is not particularly limited, but can be used as long as it can be copolymerized with acrylonitrile, vinyl chloride, or vinylidene chloride.
Methyl acrylate, methyl methacrylate, vinyl acetate,
Sodium methallyl sulfonate, sodium sulfopropyl methacrylate, sodium p-styrene sulfonate, acrylamide, methacrylamide, vinyl bromide, vinylidene bromide, etc. used for the purpose of improving dyeability and other physical properties, polymerizable emulsifiers, etc. is commonly used.

The flame retardants used in the present invention are zinc oxalate, zinc phosphate, and zinc borate alone or in combination, and may also be used in combination with other flame retardants.

Flame retardants to be combined with these include, for example, inorganic metal compounds such as antimony trioxide and metastannic acid, aromatic halides such as hexabromobenzene, aliphatic halides such as chlorinated paraffin, and tris(2,3-dibromoglobyl) phosphate. These include halogen-containing phosphorus compounds such as, organic phosphorus compounds such as dibutylaminophosphate, and inorganic phosphorus compounds such as ammonium polyphosphate.

The above-mentioned zinc oxalate, zinc phosphate, and zinc borate can be used alone, in combination, or in combination with other flame retardants, but if added at 0.4% by weight or more to the acrylonitrile polymer, the flame retardance will improve. However, if the amount added is increased, the flame retardant effect will be even greater.

If the amount added is less than 0.4% by weight, the effect is not obvious, and if it is more than 20% by weight, it will adversely affect the properties of the fibers and is economically disadvantageous.

Even when antimony trioxide, metastannic acid, etc. are used as a flame retardant in combination with these zinc compounds, the total amount of flame retardant is preferably up to 20% by weight.

It is not clear why dye discoloration does not occur when zinc oxalate, zinc phosphate, or zinc borate is used, but unlike other zinc compounds, zinc oxalate, zinc phosphate, and zinc borate are stable in weak acid dye baths and do not elute. Even if it does not elute or elutes slightly, the staining bath P
It is assumed that this is to prevent H from increasing.

These additives are added to the acrylonitrile polymer before spinning, and the method may be either dry spinning or wet spinning.

In this case, the solvent may be any solvent as long as it dissolves the acrylonitrile polymer, such as acetone, acetonitrile, dimethylformamide, dimethylacetamide, and the like.

Next, Examples will be shown, but before that, a method for evaluating the flame retardance of fibers will be explained.

Flame retardancy was evaluated using the oxygen index method (JIS K7201-1
972).

The oxygen index method measures the minimum oxygen concentration required to continue combustion by changing the mixing ratio of oxygen and nitrogen.

Generally, the flame retardancy of fibers is evaluated in the state of woven fabrics, but in woven fabrics, the combustibility varies depending on the number of twists, thickness, number of threads, etc., so it is difficult to evaluate the flame retardance of the fibers themselves. ni (i.

Therefore, in order to evaluate the flame retardance of the fiber itself as much as possible, a twisted filament sample was prepared and evaluated using the oxygen index method.

That is, 12 filaments of 3 denier and 300 pieces were twisted, heat set, and stood upright in the holder of an oxygen index tester, and the percentage of oxygen required for this sample to continue burning as 5CrIL was measured.

Example 1 Fiber base resin composition contains 50.0% by weight of acrylonitrile
, vinyl chloride 46.0% by weight, methyl acrylate 3.0
An acrylonitrile polymer consisting of 1.0% by weight of sodium p-styrene sulfonate was dissolved in acetone to a resin concentration of 20.0% by weight, and various flame retardants as shown below were added to this. was added to prepare a spinning stock solution.

Next, this stock solution was spun in an acetone-water system using a nozzle with a nozzle diameter of 0.1φ1, dried at 120°C, then hot-stretched by 300%, heat-treated at 140°C for 5 minutes, and sampled using the method described above. The flame retardancy of each sample was evaluated using the oxygen index method described above.

As is clear from Table 1, the oxygen index increases in the materials to which zinc oxalate, zinc phosphate, and zinc borate are added, similar to those to which other zinc compounds are added, and an improvement in flame retardancy is recognized.

In addition, these flame retardant-added fibers were dyed under normal conditions, and the reflectance (R) of the dyed fibers was 4.
The degree of staining discoloration was measured using the Kubelka-Munk function (K/S
)=(1-R)2/2R.

As shown in Table 1, no dye discoloration was observed in the fibers to which zinc oxalate, zinc phosphate, and zinc borate were added.

Dyeing Condition Example 2 An acrylonitrile polymer whose fiber base resin composition is 54% by weight of acrylonitrile, 35% by weight of vinyl chloride, and 11% by weight of vinylidene chloride was added to dimethylformamide so that the resin concentration was 24.0% by weight. Dissolve and add 0.4 to 20% by weight of zinc borate based on the resin,
The flame retardancy of a sample prepared in the same manner as in Example 1 and spun in the same manner as in Example 1 was measured by the oxygen index method, and the results are shown in Table 2.

Example 3 An acrylonitrile polymer consisting of 38.0% by weight of acrylonitrile, 61% by weight of vinyl chloride, and 1.0% by weight of sulfopropyl sodium methacrylate was dissolved in acetone to a resin concentration of 23% by weight, and Various flame retardants were added in combination with zinc oxalate as described below, and spinning was carried out under the same conditions as in Example 1.

Samples were prepared in the same manner as in Example 1, and the measured flame retardance is shown in Table 3.
The effectiveness of the combination was observed.

Furthermore, as in Example 1, no dye discoloration was observed and the result was good.

Example 4 An acrylonitrile polymer consisting of vinyl chloride and acrylonitrile in the following proportions was dissolved in dimethylformamide to prepare a spinning stock solution, and 5% by weight of zinc phosphate was added to the resin, and the resulting fiber was spun. The flame retardance (oxygen index) measured in the same manner as in Example 1 was as shown in Table 4.

Claims (1)

[Claims] 1. An acrylonitrile polymer consisting of 20 to 80% by weight of acrylonitrile and 80 to 20% by weight of vinyl chloride and/or vinylidene chloride, and one or more selected from zinc oxalate, zinc phosphate, and zinc borate. An acrylic synthetic fiber with good dyeability and excellent flame retardancy, which is obtained by adding two or more types in an amount of 0.4 to 20% by weight based on the polymer and spinning the fiber. 2. The acrylic synthetic fiber according to claim 1, wherein antimony trioxide and/or metastannic acid are added such that the total amount of flame retardant is up to 20% by weight based on the polymer.