JPS58149937A - Polyacrylonitrile polymer composition - Google Patents

Abstract

PURPOSE:To provide a polyacrylonitrile polymer compsn. which can stably give expanded moldings having an arbitrary, uniform expansion degree, consiting of polyacrylonitrile polymer, a solvent therefor, water and a specified thermoplastic elastomer. CONSTITUTION:100pts.wt. polyacrylonitrile polymer contg. at least 40wt% acrylonitrile, 5-40pts.wt. water, 1-40pts.wt. thermoplastic elastomer consisting of a conjugated diolefin and a monovinyl-substd. arom. compd., and not more than 20pts.wt. solvent for polyacrylonitrile polymer are mixed together. In order to // improve uniform expandability and moldability in the expansion molding of the above compsn., it is preferred to blend further inorg. particles in an amount of 0.1-50pts.wt. based on that of said compsn. By blending said inorg. particles, the melt viscosity of the compsn. is lowered, and a uniform, fine cellular structure can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The invention relates to melt-formable polyacrylonitrile-based polymer compositions. The H-like part is,
Fiber with excellent melt moldability.

It is an object of the present invention to provide a polyacrylonitrile polymer composition that can be easily molded into films and other molded products by a melt molding method. In particular, the present invention provides a polymer composition suitable for molding foamed fibers and other foamed molded articles.

A polyacrylonitrile polymer containing acrylonitrile as a main component (hereinafter referred to as PAF'll yarn polymer) is a polymer that can be easily converted into S- by heating, and its molding method involves dissolving it in a solvent. Generally, wet or dry methods are used.

Conventionally, many attempts have been made to melt-mold PAh-based polymers. For example, (1) a method of mixing a PAN polymer as a solvent or an organic compound having a high dielectric constant as copper (Japanese Patent Publication No. 31-7065, U
S P 2585499, U S P 33882,
(2) Add water using the water method (U.S.P. 25
85444, JP 1848-49839 Newsletter,! -m
54-93122), (31 Method using a mixture of water and inorganic particles or water-based polymers as a plasticizer (%-
@47-9805, Japanese Unexamined Patent Publication No. 48-52832, USP 3402231), etc. have been proposed. However, all of the above methods have the following drawbacks for industrial application.

In method 11, the plasticizer must be used in a state that is substantially moldable, and in order to obtain molded products with excellent physical properties, a plasticizer extraction and recovery step is essential. It is also possible to reduce the amount of lubricant and mold at high temperatures, but this is not practical because the PAN polymer decomposes and becomes discolored.

In method (2), isobaric agent extraction step 1! is not necessary, but
Because it is necessary to heat and melt at a temperature higher than the boiling point of water, when extruded into a normal pressure zone, non-uniform foaming may occur, or water vapor may blow out from the molding oriice and cause it to break, making it difficult to stabilize a uniform molded product. What you get is separation. In method (3).

Although this method is useful as a method for producing pulp-like fibers, it is difficult to produce long continuous so-called filament-like materials.

In particular, when producing a foamed molded product, it is difficult to use water as both a plasticizer and a foaming agent, so the method (2) above is used. However, in this method, in order to increase the degree of INK foaming mentioned above, the amount of water is increased (this will result in more cuts due to the blowing out of steam), and if the amount of water is decreased, the viscosity of the melt increases, making molding difficult. At the same time, the degree of foaming becomes low and non-uniform foaming occurs, making it difficult to stably obtain a foam molded product with a uniform degree of foaming.

Non-explosion@Kan, etc. are the result of intensive research to solve various problems, specific formulations and compositions are suitable for melt molding, and foaming with any uniform foaming degree in %. It was discovered that the present invention is suitable for stably producing a molded article, and the present invention was achieved.

That is, the gist of the present invention is as follows.

■ PA containing less acrylonitrile (both 401% by weight)
100 parts by weight of N-based polymer, 5 to 40 parts by weight of water, 1 to 40 parts by weight of a thermoplastic elastomer (hereinafter referred to as thermoplastic elastomer 7) consisting of a conjugated diolefin and a monovinyl-substituted aromatic compound, and PAN 'jlf'll type polymer composition φ consisting of 20 parts by weight or less of a solvent for the type polymer
100 parts by weight of a PAN-based polymer containing at least 40% by weight of acrylonitrile, 5 to 401 parts of water [the remainder, 1 to 40,311 parts of heat-sealable elastomer, 201 parts or more of PAN yarn coalescing agent] and a small amount (both 111 parts by weight or more) 0 inorganic particles
．． The invention will be described in detail below. In the present invention, 5 PAN yarn 1 "combined" means acrylonitrile alone or acrylonitrile containing at least 40% by weight, more preferably 60% by weight or more of a binder, and the remainder consisting of at least one ethylenically unsaturated compound. It is. Here, the term "unsaturated compound" refers to vinyl chloride, vinyl bromide, vinyl fluoride; vinyl halides such as vinyl chloride, and vinylidene halides such as diacrylic acid, methacrylic acid, maleic acid, itaconic acid, etc. Unsaturated carboxylic acids and these -*; methyl acrylate, methyl acrylate, butyl acrylate, octyl acrylate; acrylic esters such as methoxy acrylate, phenyl acrylate, cyclohexyl acrylate; methacrylic acid Methacrylic acid esters such as butyl, methacrylic acid, methoxyethyl methacrylate, methacrylate allyenyl, methacrylic cyclohexyl; vinyl formate, vinyl vinyl, propionic vinyl, iron vinyl, benzoic acid Vinyl esters such as vinyl - vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; acrylamide and its alkyl substituted products; vinyl sulfonic acid.

Unsaturated sulfonic acids such as p-styrenesulfonic acid♦ and salts thereof; styrene, --methylstyrene.

Styrene and its alkyl or halogen substituted products such as chlorostyrene 7; allyl alcohol and its esters or ethers; basic vinyl compounds such as vinylpyridine, vinylimidazole and dimethylaminoethyl methacrylate; acrolein.

These include vinyl compounds such as methacrolein, vinylidene cyanide, pricidyl methacrylate, and methacrylonitrile, and include mixtures thereof.

In order to achieve the objectives of the present invention, the blending ratio of the PAN polymer, water, thermoplastic elastomer, PANif&polymer solvent, and inorganic particles is important.

When obtaining a molded body from a composition of only PAN system 1 coalescence and water, as in the conventional technology, for example, when trying to produce a foamed molded body, it is necessary to adjust the degree of foaming and #l#! Since controlling the viscosity of a product requires polymerization, it is extremely difficult to stably produce a molded product with a uniform degree of foaming.

The composition of the present invention can solve this problem, and the respective blending ratios will be described below.

The amount of water is 5 to 4 per 100 weight 11 of the PAN polymer.
It is 0 parts by weight. . Preferably it is 10 to 30 parts by weight. If the amount of water exceeds 40 parts by weight, when extrusion molding is performed using a normal extruder, water vapor may blow out from the molding orifice, or water may separate, causing puncture flow toward the porcelain feed hopper. Problems such as the raw material polymer becoming defective occur frequently.

If the amount of water is less than 5 parts by weight, the melt viscosity increases and molding becomes difficult, resulting in poor foaming.

In addition, raising the molding temperature in order to lower the viscosity is not preferable because decomposition and discoloration become more likely. One composition of the present invention is
An important feature is that it contains a thermoplastic elastomer.

In the present invention. The feeding effect of thermoplastic FSTMER is
It is said that stable molding is possible by improving the fluidity of the material during molding. In addition, when molding a foamed product, it has the advantage that a product with a uniform degree of foaming and a high degree of foaming can be obtained.

The monopolable elastomer as used in the present invention is a block copolymer composed of a conjugated diolefin and a monovinyl-substituted aromatic compound, and is represented by the following general formula.

-B-A (A-B)n B-(A-B)n (A-8)□. -A (A-B)nX (wherein A is essentially a monovinyl-substituted aromatic compound/grotter, B is one conjugated diolefin block, X is carbon or hydrocarbon bulk, carbonyl group, phosphorus, bulk, alkyl The block copolymers represented by these general formulas can generally be obtained as follows. That is, by using a lithium hydrocarbon as a polymerization initiator in a hydrocarbon-based solvent and adding a conjugated diolefin and a monovinyl-substituted aromatic compound simultaneously or alternately, blocks of each polymer are produced. . A block copolymer of a desired shape can be obtained by changing the order and number of additions or by using a coupling agent.

C When conjugated diolefin and monovinyl-substituted aromatic compound are added alternately and polymerized, the polymerization of the compound added first is completed,
Alternatively, any polymerization method may be used in which the next compound is added and polymerized once the polymerization is completed.

Further, these thermoplastic elastomers may be used alone or in a mixture of two or more.

The conjugated diolefins mentioned here include 1,3-butadiene, isoprene, 1,3-pentadiene, and 2.3-butadiene.
-dimethylbutadiene, etc., or a mixture of 211 or more thereof, and monovinyl aromatic compounds include styrene, vinyltoluene, vinylxylene, ethylstyrene, -methylstyrene, ethylstyrene, isopropylstyrene, Ethylvinyltoluene, t-butylstyrene, vinylnaphthalene, etc. or a mixture of two or more thereof can be selected. Examples of coupling agents that can be used include halogenated hydrocarbons having two or more halogen groups, phosgene, phosphorus trichloride, Wa silicon chloride, 1,2bis(methylfurlsilyl)ethane, and the like.

Further, in the present invention, the molecular weight of the block copolymer is preferably 500 to 50,000 G, and the content of the monovinyl-substituted aromatic compound is preferably 1'O to 70% by weight.

The blending amount of the thermoplastic elastomer is 10% of the PAN polymer.
The amount is 1 to 40 parts by weight, preferably S to 30 parts by weight, based on 0 weight 11K. If the blending amount is 40 parts by weight or more, the physical properties of the molded product will change drastically and the characteristics of the PAN polymer, such as weather resistance, I& resistance, and chestnut resistance, will be impaired. In addition, if the blending amount is 1 part by weight or less, most of the flLIII
The nature of PA remains unchanged, and the purpose of the present invention is to improve PA as described above.
This can be achieved by blending water and a thermoplastic elastomer with an N-based polymer, but in order to improve moldability, PAN
It is desirable to incorporate solvents into the polymer system.

The solvent for the 5PAN polymer used in the present invention is generally known, and dimethylformamide, dimethylacetamide, dimethylsulfoxide, r-butyrolactone, ethylene carbonate, sulfoC2, etc. can be used.

The amount of the scissor solvent to be blended is 20 parts by weight or less per 100 parts by weight of the PAN polymer. If the amount is 20 parts by weight or more, even if the amount is increased further, the viscosity lowering effect is small, the amount of solvent remaining in the molded product increases, and the disadvantage of deteriorating the physical properties of the molded product is noticeable, so this is not preferred.

Furthermore, in the case of foam molding, it is more desirable to blend inorganic particles in order to improve uniform foamability and moldability.

The effect of blending the inorganic particles is that, although the buried pores are not clearly ρ, the melt viscosity of the composition is further reduced and a uniform and fine pore structure can be obtained.

The inorganic particles referred to in the present invention are inorganic particles that are not substantially dissolved in water and the solvent of the PAN polymer and have an average diameter of 40 μm or less. Specifically, carbonic power ^ sium, ai
m Magnesium, barium carbonate.

Kaolin, alumina, Merck, *Titanium oxide, and mixtures thereof can be used, but when calcium fluoride, kaolin, and Merck are used as the base material, the effects of the present invention described above are most pronounced, and these are desirable inorganic substances. It is a particle.

The blending amount of these inorganic particles is 11% of the inorganic particles used.
Although the optimum range differs depending on 111, it is 0.1 to 50 parts by weight based on the weight of the PAN polymer Zoo, and more specifically, 0.1 to 20 parts by weight for calcium carbonate.
Parts by weight are preferably 0.2 to 15 parts by weight, and for kaolin and talc, 5 to 50 parts by weight, preferably 5 to 40 parts by weight. If the amount exceeds the upper limit, the molded product will become brittle and the physical properties will significantly deteriorate. In addition, in the case of the amount of viscera (lower than the lower part of the body), the above-mentioned effects aimed at by the present invention cannot be achieved, and when foaming and extrusion is carried out, the bubbles due to foaming are coarse and only uneven molding is obtained.

As described in detail above, the present invention involves blending the PtN polymer, water, and thermoplastic two-stomer in a specific ratio, and even if any of them is missing, the desired effect of the present invention cannot be obtained. do not have. Furthermore, the effect can be further increased by adding a PAN polymer solvent and inorganic particles to the iron composition.

When molding using the composition of the present invention, it must be made into an S-melt state, but various methods can be used to do so.

That is, (a) PAN polymer, water, and thermoplastic elastomer in a specific ratio are uniformly mixed with a solvent for the PAN polymer and inorganic particles as necessary using a suitable mixer such as a gate-lumil. The powdered composition is heated in a sealed container such as an autoclave. A method of supplying the granular composition of (cI3 above 0) to the hopper of a molded screw extruder and heating and melting it while transferring it in a heating zone, (when using a /-9 screw extruder, The PAh-based polymer, thermoplastic elastomer, and inorganic particles as needed are supplied from Netsuba, and the solvent for the PAN-based polymer is water S* or a water dispersion liquid as required. 1. In the middle of the extruder It is possible to adopt a method in which an injection hole is provided in a suitable tube place to inject the material, and then the material is heated S* while being transferred through a heating zone.

The heating temperature is 120 to 200°C, preferably 150°C.
~190°C. If the temperature is below 12Q'C, it will be difficult to melt and molding will be difficult, and if it is above 200°C, the polymer will decompose and color easily, making it impractical.

The PAN-based polymer composition obtained by
It has excellent shapeability and can stably produce a uniform foam molded product when producing a foam molded product for tatami mats.The present invention will be explained in more detail with reference to Examples below.

The present invention is not limited in any way by these examples.

--The degree of foaming described in the examples was determined by the following method.

The degree of foaming in the present invention is defined as the reciprocal (1/D) of the apparent density (D) measured by the following method.

Method for measuring apparent density (D): First, carefully consider a fibrous material as a sample for measurement, and randomly select 1 (
Take 10 samples of m length. Each sample is regarded as a cylinder, and the maximum and minimum diameters of each sample are kept constant and their average value is determined (d). From this average diameter, the volume of each sample (
(ma) is calculated using the following formula.

■=πa''/a Furthermore, let the sum of each Ma be the apparent volume (enemy), while keeping the total weight of lO samples constant W?) Apparent density (calculating the average D= W/V (y/mB) and melt viscosity were measured using a Koka flow tester at 180°C with a diameter of 1
The apparent viscosity is constant under the condition of an extrusion load of 30 kvat using an orifice having a pore of L/D=1.

Example 1 A thermostatic material consisting of a PAN polymer consisting of 90% by weight of acrylonitrile and 10% by weight of methyl acrylate, and 3 blocks of (styrene)-(butadiene)-(styrene) containing 40% by weight of styrene. Elastomer, a thermoplastic elastomer consisting of four blocks of (butadiene)-(styrene)-(1-tadiene)-(styrene), and a block consisting of 1(styrene)-(butadiene))4si containing 40% by weight of styrene. A granular composition was prepared by uniformly mixing the polymers in a ball mill with the formulation shown in Table 1, and the 1III viscosity was measured using a Koka type flow tester. For melting the sample, keep the sample at a constant temperature (18
After filling the cylinder at 0° C., the Oriice was plugged and held for 2 minutes.

Thereafter, the orifice was quickly uncorked and extrusion was resumed. Column fixed! The situation of the pot and the obtained extrudate is shown in Table 1.

In Table 1, the composition of the composition is in parts by weight.
-(phtadiene)-(styrene), C;((styrene)
-(butadiene))4Si solvent EC; ethylene carbonate, α-BL; α-bunarolactone.

(Remaining color below) Thermoplastic elastomer 2 consisting of 4 blocks of 92% by weight acrylonitrile and methyl(butadiene) acrylate-(styrene)-(butadiene)-(styrene)
A composition containing 0 parts by weight and 10 parts by weight of Merck was prepared in the same manner as in Example 1, and the granular composition was produced from a hopper in a single screw extruder having three heating zones. supply.

Foam extrusion was performed. Counting from the raw material supply hopper side
120℃ for the second heating zone, 170℃ for the second heating zone, and 180℃ for the third heating zone.
℃, and the spinning oriice was set at 190C. The spinning oriice having one pore of 1 liter diameter was used and extruded at an extrusion pressure of 901 mm. 150% of the extruded foam extrudate
A foamed fiber was obtained by winding at a speed of m/min. The spinning conditions and the degree of foaming of the obtained foamed fibers are shown in Table 2 together with comparative examples.

Example 3 Using the composition of Example 2, injection molding was performed using a plunger-type small-sized injection molding machine (KJ, Debuta Kikai Kogyo Co., Ltd.).

The cylinder temperature was 200°C, and the lid temperature was 90°C. The molded product obtained was milky white, smooth, and tough.

Comparative Example 1 Same PAN heavy weight as Example 2, 100 weight IUK [
A composition containing 40 parts by weight of water was prepared and extruded using the same equipment and conditions as in Example 2. Extrusion pressure is 20~50ψ
It fluctuated in the range of -3. The results are shown in Table 2.

Claims (1)

[Claims] 1,031 parts by weight of a polyacrylonitrile polymer containing at least 40% by weight of acrylonitrile and 5 to 40 parts of water
A polyacrylonitrile polymer composition comprising 1 to 40 parts by weight of an fIII fuzzy elastomer consisting of a conjugated diolefin and a monovinyl-substituted aromatic compound, and 20 parts by weight or less of a solvent for a polyacrylonitrile polymer.
2. The polyacrylonitrile according to item 881, wherein the l1knllll elastomer is a block copolymer of a conjugated diolefin and a monovinyl-substituted aromatic compound, containing 10 to 70% by weight of a monovinyl-substituted aromatic compound. based polymer composition 3, at least 4 acrylonitrile
Polyacrylonitrile system containing 40% by weight of 14 to 100%
Parts by weight and amount of water 5-4011 11. 1 to 40 parts by weight of a thermal elastomer consisting of a conjugated diolefin, a monovinyl-substituted aromatic compound, and τ, 20 parts by weight or less of a polyacrylonitrile-based combined solvent, and a small amount (0.1 to 50 parts by weight of inorganic particles of 11 m in length) a polyacrylonitrile polymer composition 4 consisting of parts by weight, the thermoplastic elastomer containing a monovinyl-substituted aromatic compound in an amount of 10 to 7031%;
The polyacrylonitrile polymer composition 5 according to claim 113, which is a block copolymer of a conjugated diolefin and a quinovinyl-substituted aromatic compound, wherein the inorganic particles are selected from calcium carbonate, kaolin, and talc. The polyacrylonitrile polymer composition according to claim 3