JPS5918721A - Preparation of aromatic polyamide - Google Patents

Abstract

PURPOSE:To prepare an aromatic polyamide, directly, in one step, without producing by-products nor necessitating diamination process, by the addition polymerization of a polyisocyanate compound with a specific aromatic compound in the presence of a Friedel-Crafts catalyst. CONSTITUTION:The objective aromatic polyamide is prepared by the addition polymerization reaction of (A) a polyisocyanate compound having two or more isocyanate groups, e.g. m-phenylenediisocyanate with (B) an aromatic compound of formula I [R is 1-5C alkyl, -OR' or group of formula II (R', R'' and R''' are 1-5C alkyl); n is integer of 1-4] (e.g. p-xylene) in the presence of (C) a Friedel-Crafts catalyst such as anhydrous aluminum chloride.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a novel method for producing aromatic polyamide,
Further details: Directly from the aromatic compound in one step without diaminating or dicarboxylating the compound,
Moreover, the present invention relates to a method for producing aromatic polyamide without producing by-products.

[Prior art and its problems]

Conventionally, the basic method for producing aromatic polyamides has utilized a polycondensation reaction between an aromatic diamine compound and an aromatic dicarboxylic acid compound or its acid halide. The obtained aromatic polyamide has excellent heat resistance and mechanical strength properties, but on the other hand, it has a high melting point and high crystallinity, and has poor solubility in organic solvents, making injection molding impossible. . Therefore, it is extremely difficult to form fibers, films, coatings, etc., which is a significant practical limitation. For this reason, research on aromatic polyamides that also have excellent moldability has been carried out, for example, in U.S. Patent No. 3,094,511, Journal of Polymer Science, Polymer Chemistry Edition, Vol.
In Volume 5, page 1905 (1977), etc., 4f'',
Aromatic polyamides containing alkyl-substituted phenylene bonds shown in the Ushita formula have been proposed. Such polyamides have excellent moldability and heat resistance.

As shown in the following reaction formula (%) [3], the diaminated form of xylene (1) and aromatic diacid chloride CI+) are subjected to a polycondensation reaction to obtain polyamide CIII).

However, this reaction had serious drawbacks. First, many steps are required to diaminate the xylene prior to this reaction, resulting in an overall high cost. Second, since this reaction is a polycondensation reaction, it produces hydrogen chloride as a byproduct. This hydrogen chloride inhibits the polycondensation reaction and corrodes the reaction equipment, so it is not suitable for industrial use. Thirdly, since both the diaminated form CI) and the diacid chloride form [11] of the reaction reagents are unstable, it is difficult to handle them in a concentrated manner.

[Purpose of the invention]

The present invention solves the above-mentioned drawbacks in the production method of octa-aromatic polyamides, and it is possible to directly produce aromatic compounds in one step without diaminating or dicarboxylating the aromatic compounds, and to produce by-products. It is an object of the present invention to provide a method for producing aromatic polyamide without producing.

[Summary of the invention]

Kienori] is a boI having two or more incyanato groups.
J (represents a sonanate compound and a general formula mino group,
R', R" and 1" each represent an alkyl group having 1 to 5 carbon atoms, and n represents an integer of 1 to 4. ) with an aromatic compound represented by the following formula in the presence of a Friedel-Krach type catalyst.

Examples of the polyinsyanate compound having two or more polyinnoanato groups used in the present invention include m-phenylene diisocyanate, P-phenylene diisocyanate, and 2.4-)solenediisocyanate. ), 2.6-) rylene isocyaner), 2.6-xylene-1,4-diisocyacyl-1-,1-methylbenzene-2,4,6-
Triisocyanate, 1゜3.5-) phenyl polyisocyanate and its derivatives such as dimethylbenzene-2,4,6-dolyisocyanate, vinenyl-4,4-diyne/anate, vinenyl-2.4 .4'-) linocyanate dinoenylmethane-4,4'-diisocyanate, 2,2-dimethyldinoenylmethane-4,4'-diisocyanate,
diphenylneedle-l,4'-diisocyanate,
diphenyl sulfide-4+4'-diincyanate,
dienylsulfone-4,4'-diisocyanate,
diphenylmethane-2,4,4'-triisocyaner)
, 11,4'-dimethyldinoenylmethane-2,2'
, 5,5'-tetraisocyanate and its derivatives: or naphthalene polyisocyanate such as naphthalene-1,5-diisocyanate, naphthalene-1,3,7-) diisocyanate 41) nato and its derivatives.

or triphenylmethane polyisocyanate and derivatives thereof such as triphenylmethane-4,4'-diisocyanate and triphenylmethane-4,4',4''-triisocyanate;

Among these, in the method of the present invention, diphenylsulfone-4,4'-diisocyanate, +71p-7 enylene diisocyanate, [1-phenylene diisocyanate, 2,4-)lylene diisocyanate, diphenylmethane-4 , 4'-diisocyanate, Nasurin-1
,5-diincyanate is preferred.

Examples of aromatic compounds used in the present invention include alkyl compounds such as toluene, ortho-xylene, metakylene, para-xylene, mesitylene, durene, paradi(ethyl)-henzene, barage(isopropyl)-benzene, and tert-butylbenzene. Replanted benzene compound, anisole, metage(methoxy)-benzene, 1,3.5-)
! J (Me)-Y-C)-benzene and other alkoxy group-substituted benzene compounds, ``N,N-dimethylanine,''
■, :3-di(N,N-dimethylamino)-benzene,
Examples include tertiary amine group-substituted benzene compounds such as 1,3.5-)su(N,N-dimethylamino)-benzene.

Among these, in the present invention, baraxylene and mesitylene are used.

1.3.5-trimethoxybenzene, N,N-dimethylamino'', 1+3+-di(N,N-dimethylamino)benzene are preferred.

one! , Friedel-Krach type catalysts used in the present invention include aluminum chloride, ferric chloride, tin chloride,
Inorganic acids such as titanium chloride, zinc chloride, antimonochloride, indium chloride, copper chloride, boron trifluoride, phosphorus trifluoride, phosphorus pentoxide, fluoroboric acid, fluorinated acid, hydrochloric acid, sulfuric acid, heteropolyacid, etc. Examples include organic acids such as P-)luenesulfonic acid.

As the production method of the present invention, any commonly used polyaddition reaction method can be applied. Preferably, bulk polymerization or solution polymerization is used.

Among these, in the case of female polymerization, it is preferable to heat the reaction reagent and catalyst while stirring to bring them into a uniform state, and then polymerize. Although a high molecular weight polyamide can be obtained by a reaction of 0° to 250' for 0.1 to 30 hours, in the case of solution synthesis, it dissolves the reaction reagent and reaction intermediate, and does not cause side reactions with the reaction reagent. Preferably, a solvent is used. 0
Polyamide pieces of polymeric pieces are obtained with a reaction time of 1 to 40 hours.

The above-mentioned solvents include 0-dichlorobenzene, 1,
3,5h') Chlorobenzene, nitrobenzene, nitromethane, carbon tetrachloride, etc. can be exemplified. The use of solvent 'Ir1-' is 2 to 5 with a ratio of 11 to the reaction reagent.
I like that it is 0x.

In any of the above-mentioned polymerization methods), the blending ratio of the polyin heptaanate compound and the aromatic compound used is preferably equimolar in order to smoothly proceed with the polyaddition reaction.

The fI4- of the free-tyl-chloride type catalyst varies depending on the reaction reagent and polymerization conditions, but is 0.3 to 4.
It is preferable that the range is between 0 and 0.

In the method of the present invention, an example of a treatment method after the completion of the polyaddition reaction described above is to carbamate JF by adding methanol to carbamate the remaining incyaner, pour it into ice water, and then collect the precipitate from house to house. The desired polyamide can be obtained by performing conventional treatments such as washing < j + 7 drying.

[Effects of the Invention] According to the present invention, polyamide can be produced from the aromatic compound in one step in 1α phase without requiring a step of diaminating the aromatic compound. Since the present invention is a polyaddition reaction, by-products such as ice and hydrogen chloride are not produced. Therefore, the reaction operation is simple, and at the same time, corrosion of the reaction equipment does not occur, so it is of great industrial value.

[Embodiments of the invention]

Example 1 In a nitrogen gas atmosphere, 42.47 (0.4 mol) of P-xylene and anhydrous aluminum chloride were added to a four-piece flask equipped with a nitrogen gas inlet tube, a reflux condenser, a thermometer, and a stirring persimmon. Add 106.7 g (0.8 mol) of m-phenylene diisocyanate and stir it once.
(0.8 mol) was added in small portions over about 30 minutes, then heated to 80°C and reacted for 5 hours, and then heated to 80°C for 5 hours.
The reaction was carried out at 0'O for 5 hours.

A dark red solid polymer was obtained. 200ml of methanol was added to this (after reacting with the remaining incyanate groups, it was poured into 34 cups of ice water with stirring.Then, the whole was filtered and the precipitate was separated from each other, and this precipitate was washed with methanol and acetone. After drying, dimethylformamide (
DMF) and the resulting solution was poured into 21 liters of water. Further, the whole was filtered, and the precipitate was separated and dried to obtain 767 g of white powder (yield: 72%).

A strong film could be formed from this polymer by melting it. The IR spectrum (f (Br bowl method) showed strong amide group absorption at 1645rnL-', 331(b:m-').The melting point (mp) was 381°.
C1 intrinsic viscosity Cη) 0.43 (0.5g/101
00m1D, 30"0), heating loss measurement using a differential thermal balance (5"O/min + air), 350
The weight did not decrease to 'O' (hereinafter, the heating weight loss start temperature is expressed as Td).

Example 2 Nitrobenzene 500md, P-xylene 42.47g
(0.4 mol) 120.12 g (0.4 mol) of todiphenylsulfone-4,4'-cyincyaner),
After reacting at 120'C for 10 hours in the presence of 106.7 g (0.8 mol) of anhydrous aluminum chloride, methanol 8
00 nJ was added, and after separating the precipitate, it was post-treated in the same manner as in Example 1 to obtain 139.8 g of white powder (yield: 86%). This polymer has rnp: 320'0.77:0.
89, Td: 305'0.

Example 3 Diphenylsulfone in 200 mg of nitrobenzene
30.03 g (0.1 mol) of 4,47-diisocyanate and 13.42 g (0.1 mol) of durene were added in the presence of 26.7 g (0.2 mol) of anhydrous aluminum chloride.
120' After reacting for 0.6 hours, the same 4) ρ as in Example 2
After post-treatment, 40.0 g of white powder (yield 92%) was obtained.

This polymer is N,N-dimethylacetamide.

N-methyl-pyrrolidone, m-cresol, etc.
7, it was possible to form a tough film by melting. mp: 345'C% η20.73.1
"d: It was 312°C.

Example 4 12.12 g (0.1 mol) of N,N-dimethylaniline in 200 mg of nitrobenzene
After reacting 25.024 (0.1 mol) of 4,4'-diisocyanate in the presence of 26.7 g (0.2 mol) of anhydrous aluminum chloride at 150'C for 10 hours, the same reaction as in Example 2 was carried out. After treatment, 29.0 g of yellow powder (yield 78%) was obtained.
) was obtained.

This polymer has mp:346'o, 77:0.47
゜1''d: 308'O.

Example 5 Nitrobenzene 2.4-) in 20Omd! Jv:
17.42 g (<0.1 mol) of N,N'-dimethylaniline and 12.12 g (0.1 mol) of N,N'-dimethylaniline in the presence of 26.7 g (0.2 mol) of anhydrous aluminum chloride. After reacting for a period of time, the mixture was post-treated in the same manner as in Example 2 to obtain 19.2 g of white powder (yield: 65 g).

A strong film could be formed from this polymer by melting it. mp: 327'O, η: 0.39, Td
: 318'O.

Claims (1)

[Claims] It represents a polyisocyanate compound having two or more incyanato groups and an alkyl group of 1 to 5, and n represents an integer of 1 to 4. ) in the presence of a Friedel Krach type catalyst.