JPS60133012A - Preparation of fine particles of acrylonitrile polymer - Google Patents

Abstract

PURPOSE:To obtain industrially advantageously the titled fine particles having uniformity, fineness, and improved stability when it is allowed to stand, by polymerizing acrylonitrile in an organic solvent to dissolve it but not polyacrylonirile in the presence of a specific copolymer. CONSTITUTION:(A) Acrylonitrile (AN for short) or a mixture of >=60wt% AN and another ethylenic unsaturated compound is polymerized in (B) an organic solvent to dissolve AN but not polyacrylonitrile in the presence of (C) a copolymer consisting of >=50wt% styrene or alpha-methylstyrene and the rest of AN, to give the desired fine particles. A solvent such as toluene, etc. to dissolve an (alpha-methyl)styrene monopolymer is preferably used as the component B. EFFECT:Unconditionally applicable in various uses and fields.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process VC for producing fine, uniform and stable organic solvent dispersions of ANN polymers.

In recent years, there has been an increasing demand for synthetic polymers in the form of fine particles as modifiers for fibers, films, etc., and as surface finishing agents for paper, films, leather, etc. Among them, A.
Since N-based polymers are excellent in light resistance, S weather resistance, and solvent resistance, the application of particulate = AN-based polymers to the above-mentioned fields is strongly desired.

As a method for producing such a particulate hwfi polymer, for example, an aqueous emulsion of AN polymer was proposed in Japanese Patent Publication No. 55-2207. This emulsion is useful in applications where it is used in an aqueous dispersion state, but in order to obtain a dispersion in an organic solvent, it is necessary to separate the polymer from the aqueous emulsion and then disperse it in an organic solvent. In addition, it is extremely difficult to extract Ml itself in the form of fine particles from an aqueous emulsion because it is accompanied by aggregation, coalescence, etc. of the polymer particles σ).

Therefore, a method of directly polymerizing the AM non-monomer in an organic solvent is desired, but in general, AN, 46-terminal polymers have a strong cohesive force between the polymer particles, so if the polymer is polymerized according to a conventional method, the resulting polymer particles will improve. coalesce into coarse and bulky aggregate particles, which can no longer be separated into individual fine particles by other mechanical means, - organic solvent dispersion of fine and uniform AN polymer Obtaining the body was very difficult.

In order to overcome these problems, for example,
No. 3439'6 proposes a method for preventing agglomeration and coalescence of AN polymer particles by adding an oil-soluble polymer substance as a dispersant to increase the viscosity of the polymerized thread. It cannot be said that the preventive effect is sufficient, and since it is necessary to add a multi-H) oil-soluble polymer substance, there are considerable practical limitations.

Furthermore, in Japanese Patent Publication No. 51-8127, it has been proposed to use a monohydric alcohol with a return prime number of 1 to 4 as an organic solvent; however, this method not only limits the type of solvent used, but also The effect of stabilizing uniform dispersion is insufficient, and the publication also states that particles settle to the bottom of the container during storage.

Under these circumstances, the present inventors have attempted to produce a homogeneous, fine, and stable organic solvent dispersion of 7 ThAN threads, which has traditionally been considered difficult, to industrial advantage (as a result of intensive research, specific V). Although AN dissolves in the presence of copolymer V), P
By polymerizing AN in an organic solvent that does not decompose ANI''l1M, agglomeration and coalescence between polymer particles can be significantly prevented, thereby producing an organic solvent dispersion of an ANN polymer that is uniformly fine and has excellent storage stability. The present invention was achieved by discovering a method that can be directly produced.

The object of the present invention is also uniform-g! ! The purpose of the present invention is to provide an industrially advantageous method for producing an organic solvent dispersion of an ANN polymer having a fine particle size and excellent storage stability.
Quality M+, surface treatment agent for paper, film, leather, etc. σ]
The object of the present invention is to provide a method for producing an organic solvent dispersion of AN yarn polymer particles that can be applied to various fields of use without any restrictions.

The object of the present invention is to produce AN alone or a monomer mixture of 6% or more by weight of AN and the balance being at least one other ethylenically unsaturated compound (hereinafter referred to as AN monomer).
When polymerizing in a commercially available organic solvent in which AN dissolves but P A xi I':I does not dissolve, a copolymer consisting of 50% or more of cutylene or α-methyl 7-tyrene and the remainder AN. This can be achieved industrially advantageously by polymerizing in the presence of

The present invention will be described in detail below, but first, the main component, AIJC.
Copolymerization ratio I′i is 60% by weight or more, preferably 7
It is necessary to set it to 0% by weight or more, more preferably 80% by weight or more, and if it is outside the lower limit of this range,
It becomes impossible to exhibit the excellent properties inherent to AN-based polymers such as light adhesion, weather resistance, and solvent resistance. In addition, as other ethylenically unsaturated compounds to be copolymerized if desired, known unsaturated compounds that can be copolymerized with AN, such as H vinyl chloride,
Vinyl halides and vinylidene halides such as vinyl bromide, vinyl fluoride, vinylidene chloride, and vinylidene bromide; acrylic acid) Unsaturated carboxylic acids such as methacrylic acid, maleic acid, and itaconic acid, and their salts; (meth) Methyl acrylate, (meth)ethyl acrylate, (meth)
Butyl acrylate, octyl (meth)acrylate, methoxyethyl (meth)acrylate, phenyl (meth)acrylate, cyclohexyl (meth)acrylate, etc. (methacrylate enethers; methylhinylkaton, phenylvinylnaton, Unsaturated ketones such as methyl isopropenyl ketone; vinyl enethers such as vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl benzoate; nohinyl ethers such as methyl vinyl ether and ethyl vinyl ether; acrylamide and its alkyl substituted products Vinyl nurphonic acid, No. 7 tyrene nulphonic acid, nurfoethyl methacrylate, nurfoprovir nutel methacrylate,
Unsaturated nulphonic acids and their salts such as 2-acrylamide 2-methylpropane sulfonic acid; 7-tyrene and its alkyl or halogen substituted products such as nutylene, α-methylnutylene, and chloronutylene; allyl alcohol and its entethers or ethers; Examples include basic vinyl compounds such as vinylpyridine, vinylimidazole, and dimethylaminoethyl methacrylate; vinyl compounds such as (meth)crolein, vinylidene cyanide, glycidyl methacrylate, and trimethacrylate.

In addition, examples of dispersion media, that is, organic solvents that dissolve AN but not FA'N, include aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; pentane, hexane,
Aliphatic hydrocarbons such as heptane and ofcune; acetate enethers such as ethyl acetate, butyl acetate, isopropyl acetate, amyl acetate, and ethyl glycol acetate; ketones such as acetone, methifrethyl ketone, and methyl isobutyl ketone; methanol, ethanol , n-butanol, n-globanol, and other alcohols; cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; trichlorethyl alcohol; It is necessary to consist of at least 60% to 85% by weight of nutylene or α-methyl 7-tyrene and the remainder AN.

When using a copolymer in which the copolymerization ratio of (α-methyl)nutylene is less than the lower limit of the present invention, the ANN polymer organic solvent has a uniform fine particle size and excellent storage stability, which is the objective of the present invention. It becomes difficult to produce a dispersion.

1, the copolymer must contain AN as an essential copolymer component of less than 5011% by weight, preferably 15 to 40% by weight, and the copolymer composition must be Only then can the desired dispersion effect be fully exerted.It should be noted that the ethylene thread may be used as the fifth component of the combination without impairing the purpose of the present invention. There is no problem in using a small amount of unsaturated compounds in combination.

The method for producing the copolymer is not subject to any restrictions, but if it is polymerized in an organic solvent that dissolves the (α-methyl)nutylene homopolymer, the resulting copolymer will be in an organic solvent solution or emulsion. It is preferable that the organic solvent is obtained as a liquid and added to the polymerized thread in the form of an organic solvent solution or emulsion, since the object of the present invention can be achieved more effectively. Aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; Ethyl acetates such as ethyl acetate, butyl acetate, isopropyl acetate, amyl acetate, and ethyl glycol acetate; Ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone;
Methi 7. Cellosolves 2. Examples include cellosolves such as cello(7,butyl) and butyl cellosolve; chlorinated saturated water groups such as trichlorethylene, dichloroethane, and tetracyclic carbon.

The amount of such copolymer used is 1 to 15% by weight, preferably 2 to 15% by weight, based on the total 1+-1 of 111 AN spinning wheels.
It is preferable to use 10% i#i%, and if it is outside the lower limit of this recommended range, min+8! The stable 4J effect will be insufficient, and if the upper limit of the range is exceeded, the properties of the produced ANN polymer will be impaired and the usage will be restricted.

In addition, as a means for initiating +ti reaction during polymerization of the AN yarn monomer, conventionally known oil-soluble radical lj+4 initiators such as azo compounds and organic peroxides are used.
For example, azo thread compounds include 2.2'-azobinuisoptilonitrile, 2.2'-azobis(2-methyl-valeronitrile), 2.2'-azobis(2I4-dimethylbutyronitrile), 2.2 '-Asobia (2-methyl
capronitrile), 2121-azobis(2,3,3
-trimethylbutyronitrile), 2,2'-azobis(
2,4,4-)limethylvaleronitri/v), 2.2'
-azobis(2,4-dimethylvaleronitrile), 2.
2'-Azobis(2゜4-cytyl-4-ethoxyvaleronite!J)2.2'-Azobis(2+4
-cymethy/l/-4-n-butoxyV)<L/lonitrile), and organic peroxides include, for example, acetyl peroxide, propionyl peroxide, imbutyryl peroxide, octanoyl peroxide, decanoyl peroxide,
Lauroyl peroxide 1.3.5.5-,) Remethyl-based noyl peroxide, benzoyl peroxide, diisopropyl peroxide, di-2-ethylhexyl peroxycarbohydrate diacyl peroxides such as; t-butyl peroxyisobutyrate, t--butyl peroxy pivalate, t-
4Nf of peroxyene ethers such as butyl peroxy inodocanoate and t-butyl peroxylaurate can be used. Of course, two or more of the above oil-soluble radical initiators can also be used in appropriate combination.

In addition, the polymerization temperature varies depending on the type of organic solvent used and the type of polymerization initiator, but is approximately 4.
It is desirable to set it within the range of 0 to 100°C. If the temperature is outside the lower limit of this range, the reaction rate is low and is undesirable from the viewpoint of productivity and economy, and if it exceeds the upper limit, problems such as coloring of the polymer may occur, which is undesirable.

Furthermore, although no restrictions are imposed on the ANN thread mass concentration, it is preferably 10 to 50%, preferably 10 It is desirable to set it within the range of ~40% by weight.

The reason why the above-mentioned method of the present invention weakens the cohesive force between polymer particles and essentially produces a stable organic solvent dispersion of ANN-based polymer powder particles of 1 p or less has not yet been fully elucidated. is considered to be present in the polymerization system in the form of a solution or emulsion and effectively suppress it.

The hNfi polymer particle solvent dispersion of the present invention not only has uniform to fine particles, but also has a stable dispersion state even during long-term storage even without containing any conventional emulsifiers or dispersants. It also maintains excellent dispersibility when mixed with pigments, paints, and other molecular substance solutions, and exhibits the unique excellent properties of AN-based polymers when applied to various application fields. The special feature of the present invention is that an organic solvent dispersion of ANN-based polymer powder particles having such excellent properties can be produced industrially advantageously without the need for complicated operations. This is a desirable effect.

EXAMPLES The present invention will be described in more detail with reference to Examples below, but the scope of the present invention is not limited in any way by the description of these Examples.

Example 1 Using a No. 21 tri-rofranuco equipped with stirring blades and a cooling condenser, the mixture was heated at 60°C with the charging composition shown in Table 1 below.
Polymer solutions (a to d) of 7 tyrene and AN were prepared without polymerization for 6 hours.

Reprint of the specification (no changes to the contents) Table 1 (Note) AVN, 2,2'-azobis(2,4-dimethyl-valeronitrile) Next, using the same trilofuranuco e as above, the following 2 Polymerization was carried out for 5 hours at 60' CX with the feed composition shown in the table. Among the obtained ANJj polymer dispersions (I to ■), the polymer dispersions (I to V) according to the present invention were homogeneous and had a low molecular weight of 1μ or less. It was a viscosity dispersion (however, some aggregates were observed for AV), but Flat I and 1 were close to agglomerated paint-like.Furthermore, /16VII had a low viscosity, but However, aggregate particles were mixed in, and some precipitation occurred at the bottom of the container after being left for -1 week.

Example 2 Polymerization was carried out in the same manner as described in Example 1 with the following charge composition (however,
Polymerization temperature was 70°C).

AN' 180 (φ Methyl acrylate 10 Copolymer solution (,Q) 50 2.2'-azobifisobutyronitrile 2ethyl acetate 758 The resulting dispersion contains an AN polymer with a particle size of 1μ or less. It was dispersed in the form of fine particles, and no precipitate was observed even after one week of standing.

Comparative Example Polymerization was carried out using a three-neck fluff similar to that described in Example 1 and with the following charging composition.

Nuthylene 130 (2) AN 70 AVN 4 t-propertool 796 Polymerization temperature x time 60'''CX 5 hours The same procedure as in Example 2 was carried out except that the obtained copolymer dispersion was used instead of copolymer (Q). However, when the obtained hNi polymer dispersion was observed under a microscope, it was found that aggregate particles of 10 μm or more were mixed in, and a precipitate was formed after standing for one day and night.

Procedural amendment (method) ■, Indication of the case Patent Application No. 241854 of 1982 2, Name of the invention Acryloni) Process for producing IJ-based polymer powder particles 3, Person making the amendment Relationship with the case Patent applicant

Claims (1)

[Claims] 1 Acrylonitrile (hereinafter referred to as AN) alone or 60
When the monomer body temperature is 50ft.
% or more of nutylene or α-methyl 7-tylene and the balance is AN
A method for producing fine particles of A'NN polymer, characterized in that polymerization is carried out in the presence of a copolymer consisting of: 2. The production method according to claim 1, which uses a copolymer obtained by polymerizing in an organic solvent that dissolves nutylene or α-methylnutylene homopolymer.