JPH03166210A - Aromatic polyamide oligomer containing terminal unsaturated group and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject oligomer useful for raw material of heat-resistant aromatic polyamide capable of being synthesized at low temperature by reacting aromatic diamine, (meth)acrylamide and aromatic dicarboxylic acid dihalide in the presence of hydrogen halide acceptor. CONSTITUTION:(A) Aromatic diamine (e.g. metaphenylene diamine) is reacted with (B) (meth)acrylamide and (C) aromatic dicarboxylic acid dihalide (e.g. terephthalic acid dichloride) in the presence of hydrogen halide acceptor to afford the aimed oligomer expressed by the formula (R is H or CH3; R1 and R2 are bifunctional aromatics; n is 1-15).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an oligomer useful as a raw material for a heat-resistant synthetic resin, particularly a heat-resistant polyamide polyamide imparted with thermosetting properties, and a method for producing the same.

[Technology of the Congo Song Dynasty] As the demand for plastics industry becomes more sophisticated, industrial materials with special properties are becoming necessary, and this trend is rapidly developing as the industrial sector becomes more sophisticated. .

41.1 The requirement for improved heat resistance applies to plastics, films,
Fibers, laminates, laminates, adhesives, etc. The purpose is to add heat resistance to industrial materials in fields that require 1', expand the market, and expand into a wide range of new manufacturing areas by adding new functions.

In response to these demands, a group of synthetic resins called aromatic polyamides, polyamides, polysulfones, polyphenylene resins, and polypropylene engineering plastics have already been developed, which are different from conventional synthetic resins. Aromatic polyamides, known as aramids, are one of them, being industrially produced as plastics with new functions and opening up new demand fields. Typical aromatic polyamides include polybaraphenylene terephthalamide (product name: Kepler) and polymetaphenylene isophthalamide (product name Ninomex or HT-1) developed by Du Bont. be. All of these polyamides are essentially classified as thermoplastic synthetic resins, but they generally have a high melting point, and the difference between the melting point and the pyrolytic knitting degree is small, or even reversed in some cases. Therefore, melt molding is difficult or impossible depending on the structure. On the other hand, a type of polyamide in which an oligomer is made as a precursor and then thermally cured has not yet been proposed.
The reason why there was no thermosetting aromatic polyamide is as follows.
This is thought to be due to the fact that its melting point was generally much higher than that of conventional thermoplastic synthetic resins, and the introduction of unsaturated bonds was considered to have a high risk of causing undesirable gelation during the molding process.

[Problem to be solved by the invention] Aromatic polyamide is an excellent heat-resistant polymer that is relatively stable even at considerably high temperatures, has excellent electrical properties and mechanical strength, and has high chemical stability. ．． The purpose of the present invention is to develop raw materials for producing aromatic polyamides that have improved molding processability without losing the excellent properties of these conventional polyamides, as well as improved mechanical strength and chemical stability at high temperatures. That is. [Thousand Steps to Solve the Problems] The present inventors have found that when molded as a molding material or as a laminate, it has a relatively low melting point, can be molded into a desired shape under heat and pressure, and In order to obtain an aromatic polyamide that can be cured under relatively mild conditions and has sufficient heat resistance, mechanical strength, and chemical stability after curing, aromatic diamine, (meth)acrylamide (in the present invention, acrylamide and/or methacrylamide] and an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor to obtain an unsaturated polyamide oligomer having a terminal unsaturated group represented by the general formula. They found that the aromatic polyamide can be cured in the presence of a radical-generating catalyst, and that the cured aromatic polyamide has the above-mentioned excellent properties, leading to the completion of the present invention. For example, an aromatic polyamide oligomer can be synthesized by the following reaction formula. (Aromatic diamine) (Aromatic dicarboxylic acid dihalide) (Aromatic polyamide oligomer) In order to make the above reaction proceed smoothly, A receptor for the generated hydrogen chloride is required, and it is generally convenient to use a tertiary amine or a caustic alkali. Ligomers are advantageous because of their ease of moldability;
No polymerization is necessary at this stage. This reaction is generally carried out by mixing amines in an aqueous phase and acid chloride in an inert organic solvent that does not dissolve in water to perform an interfacial polycondensation reaction, or by dissolving both in an inert solvent and condensing them at low temperatures. This can be carried out by a low-temperature melt polycondensation reaction.
Aromatic diamines that can be used in the present invention include, for example, mekphenylene diamine, 4,4°-diaminodiphenylmethane, 4.4°-diaminodiphenylpropane, 3.
3°-dimethyl-4.4°-diaminodiphenyl methane, 4.4°-diaminodiphenyl ether. 3.4'
-diaminodiphe, nyl ether, 3,3°-diaminodiphenylsulfone, 4,4°-diaminodiphenylsulfone, dianisidine, 2,4-tolylenediamine.
2.4/2.6 -}-Lylene diamine mixture. 1
．． 3-bis(3-aminophenoxybenzene) can be used, and two or more types can be used in combination.

Acrylamide and methacrylamide are used as precursors for organic residues that form terminal unsaturated groups.

Further, as the aromatic dicarboxylic acid dihalide that can be used in the present invention, the aromatic dibasic acid dichloride 1: is convenient, and representative examples include terephthalic acid dichloride, isophthalic acid dichloride, phthalic acid dichloride, and mixtures thereof. .

The polyamide derived from fucuric acid dichloride has slightly insufficient heat resistance, and when using terefucuric acid dichloride, the fI of the polymer after heat curing is
Thermal properties are sufficient, but the melting point of the aromatic poly7amide oligomer obtained as a precursor tends to be high, making it difficult to handle.From a practical standpoint, isophthalic acid dichloride has the best balanced properties. Therefore, it meets the purpose of the present invention. This synthesis reaction proceeds relatively stoichiometrically, so after calculating n in the above formula [A],
Acrylamide, aromatic diamine, and aromatic dicarboxylic acid dihalide can be reacted, and if precise adjustment is required, the molar ratio can be determined by a simple test. As already explained, the composition of the aromatic polyamide oligomer obtained by this reaction can be easily selected, and it can be easily molded at a temperature of 200° C. or lower. The aromatic polyamide oligomer with terminal unsaturated groups synthesized according to the present invention can be cured in combination with a radical-generating catalyst, making it possible to significantly improve heat resistance. Although there is no restriction or necessity for the radical generating catalyst, a peroxide type is suitable industrially, and when the molding temperature is higher than loO'c, a so-called high-temperature decomposition type, such as a dicumyl peroxide type, is suitable. is used. The usage is 1-3pI1rfJSi! That's 1 win.

Further, the combined use of a monomer copolymerizable with the unsaturated bonds of the oligomer of the present invention is possible when the monomer dissolves the aromatic polyamide oligomer. In particular, when n in formula [A] is a small value, the range of application is wide. The combined use of monomers promotes the softening of the entire condensed yarn and improves moldability and workability, but on the other hand it reduces the heat resistance of the hardened aromatic polyamide. It is necessary to do so.

When producing a molded article using the aromatic polyamide oligomer having unsaturated end groups according to the present invention, reinforcing agents,
It goes without saying that fillers, mold release agents, coloring agents, and other polymers as low-yield shavings can be added as necessary.

Next, in order to aid understanding of the present invention, Examples will be shown below.

[Actual Fitn Example] (Example 1) (Left below) 500 equipped with a reflux condenser, dropping funnel, thermometer, and stirrer
Pour 20-3 g of isophthalic acid chloride (0.1 monomer) and 100 g of dimethynoremamide (DMF) into a four-necked seperate flask. 10℃
Cool as follows. Next, 2.37g (0.0333mol) of acrylamide
．． 3.4'-diaminodiphenyl ether (3,4
゜-DAPE) 16.67g (0.0833mol),
20.2 g (0.2 mol) of triethylamine. DM
Weigh and mix F I OOg and add dropwise to 5 reaction flasks. During this time, keep the reaction temperature below 10°C. After the dropwise addition is complete, keep the temperature of the reaction mixture below 10°C.
Continue stirring for 2 hours. The reaction mixture is then added to Xu) I in a large amount of water with vigorous stirring to precipitate crystals. The precipitated crystals are filtered by suction, washed with water, and then dried.

m. p. The infrared absorption spectrum of 145 to 160''c is shown in Figure i.

Ex-love analysis value is C. 71.25%; }l, 4.20%:
N. The theoretical value is 8.69%1'. C. 71.18%: H, 4.27%: N, 8.74%
showed good agreement. (Example 2) 500 equipped with a reflux condenser, dropping funnel, thermometer, and stirrer
20.3 g (0.1 mol) of isophthalic acid chloride was placed in a four-piece separate flask of mE. DMF1 00g
lit preparation, IO'C: G. Cool down.

Next, 2.37 g (0.0333 mol l) of acrylamide
．． 3,3°-diaminodiphenyl sulfone 20.6
7g (0.0833 mol), triethylamine 20.
2 g (0.2 mol>.80 g of DMF) were mixed and added dropwise to the reaction flask.

After the dropping is completed, the dropping funnel is washed with 20 g of DMF, and the washing liquid is dropped into the reaction flask. During this time, the reaction temperature is kept below 10°C.

After the completion of the dropwise addition γ, stirring was continued for 2 hours while keeping the temperature of the reaction mixture below 10°C.

Next is intense <11! Gradually add the reaction mixture to a large amount of stirring water to precipitate crystals. The precipitated crystals are suction filtered, washed with water, and then dried.

m. p. The infrared absorption spectrum of this product at 165-180°C is shown in Figure 2.

The elemental analysis value is C. 63.41%; H. 4.24%: N.
The theoretical value is 8.61%.C. 63.27%. IC4.27%. N. 8.7
Good agreement was shown at 4%.

(Example 3) 20.67 g of 3.3°-diaminodiphenylsulfone
(0.0833 mol) instead of 3.3"-dimethyl-1.4°-diaminodiphenylmethane 18.83 g
(The same operation as in Example 2 was performed except that 0.0833 mol was used.

m. p. The unexpected absorption spectrum of this product at 180-195°C is shown in FIG.

The elemental analysis value is C. 75.57%: H. 5.43%: N. 8
．． lil at 07%! The theoretical value is C. 75.44%: tl. 5.46%: N.
It showed a good agreement of 8.1!1%.

(Example 4) 0 3.3゛-diaminodiphenylsulfone 20.67 g (
2,4-tolylenediamine/2,6-tolylenediamine mixture (8:2) instead of 0.0833 mol)10.
Example 2 except that 17 g (0.0833 mol) was used.
I performed the same operation. m. p. The infrared absorption spectrum of this product at 155-175°C is shown in Figure 4. The elemental analysis values are: C, 69.113%: H. 4.65%: N.
The theoretical value at 10.85% is C. 69.71%: }I. 4.70%:N. 10.97
% and showed good agreement. Example 5 The same procedure as INI was carried out except that 283 g (0.0333 mol) of methacrylamide was used instead of 2.37 g (0.0333 mol) of acrylamide.

m. p. The infrared absorption spectrum at 160-180°C is shown in Figure 5.

The elemental analysis value is C. 71.49%. H, 4.35%. N. 8.5
The theoretical value at 6% is C, 71. :18%: }I. 4.41%: N
．． Good agreement was shown at 8.62%.

r effect] Is the conventional aromatic polyamide a thermoplastic resin? Ruga.
Despite having excellent properties such as chemical resistance and electrical properties due to its high melting point, it had difficulties in moldability, and its mechanical strength decreased significantly at high temperatures, so it was below the melting point or decomposition point. The present invention improves these drawbacks and, although it is the same aromatic polyamide, has excellent moldability and does not exhibit a decrease in mechanical strength even at high temperatures. less thermosetting yj
We have successfully developed an aromatic polyamide oligomer with a novel terminal unsaturated group that can be used as a raw material for aromatic polyamide. This oligomer can be synthesized at low temperatures, and although it has polymerizable double bonds, it is relatively stable and does not gel during the molding process, and due to the action of a radical-generating catalyst, it can be synthesized even at low temperatures. It has excellent properties that allow it to be easily cured. The aromatic polyamide obtained by curing this oligomer has excellent heat resistance and does not cause a decrease in strength even at high temperatures.

[Brief explanation of the drawing]

1 to 5 are infrared absorption spectrum diagrams of the terminal unsaturated group-containing aromatic polyamide oligomers obtained in Examples 1 to 5, respectively.

Claims (2)

[Claims] (1) General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ [However, in the formula, R is H or CH_3:R_1, R_2 is 2
represents a valent aromatic group, and n is an arbitrary numerical value of 1 to 15. ] An aromatic polyamide oligomer containing a terminal unsaturated group. (2) A method for producing an aromatic polyamide oligomer containing a terminal unsaturated group, which comprises reacting an aromatic diamine, (meth)acrylamide, and an aromatic dicarboxylic acid dihalide in the presence of a hydrogen halide acceptor.