JPH03166211A - Thermosetting polyamide and composition of same polymer - Google Patents

Abstract

PURPOSE:To obtain the subject composition having excellent processability, hardness at high temperature and mechanical strength by polymerizing specific aromatic polyamide oligomer. CONSTITUTION:Preferably <=5wt.% radical polymerization initiator is added to aromatic polyamide oligomer expressed by formula I (R is H or CH3; R1 and R2 are bifunctional aromatics; n is 1-15) and polymerized to afford the aimed polyamide. Besides, said oligomer expressed by formula V is obtained by, e.g. reacting acrylamide expressed by formula II with metaphenylenediamine expressed by formula III and isophthalic acid dichloride expressed by formula IV.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to heat-resistant synthetic fat crumbles, and particularly to heat-resistant aromatic polyamides imparted with thermosetting properties and thermosetting resin compositions thereof.

[Prior Art] As the demands of the plastics industry become more sophisticated, industrial materials with special properties are required, and this trend is rapidly developing as technology becomes more sophisticated.

The demand for improved heat resistance is felt in plastics, films, fibers,
This is also to add heat resistance to industrial materials that require heat resistance, such as laminates, laminates, and adhesives, to expand the market, and to expand into a wide range of new fields with new functions.

In response to these demands, a group of synthetic resins called engineering plastics, such as aromatic polyamides, bonoimides, borisulfones, and polyphenylene oxides, have already been developed, and they have novel functions different from conventional synthetic resins. Aromatic polyamides, also known as aramids, are industrially produced plastics that have opened up new fields of demand.

Examples of aromatic polyamides include polyparaphenylene terephthalamide (product name: Kevlar) and polymetaphenylene isophthalamide (product name:
Nomex or HT-1) is a typical type. All of these polyamides are essentially classified as thermoplastic synthetic resins, but they generally have a high melting point, and in some cases the difference between the melting point and the thermal decomposition temperature is small or reversed. 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 thermosetted has not yet been proposed.
The reason why there was no adhesive-curable aromatic polyamide is as follows.
This is thought to be because its melting point was generally much higher than that of conventional thermoplastic synthetic resins, and because 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 J Aromatic polyamides are relatively stable at very high temperatures, have excellent electrical properties and IJ mechanical strength, and are highly chemically stable and are excellent heat-resistant polymers. be.

The purpose of the present invention is to produce an aromatic polyamide that has improved moldability without losing the excellent properties of conventional polyamides, and has improved mechanical strength and chemical stability at high temperatures. ．． [Means for Solving the Problems] The present inventors found that when molded as a molding material or as a laminate, it has a relatively low melting point and can be molded into a desired shape under heat and pressure. We conducted research to obtain an aromatic polyamide that can be cured under mild conditions and has sufficient heat resistance, mechanical strength, chemical stability, etc. after curing, and developed the general formula (hereinafter in the margin)... [11] We found a thermosetting aromatic polyamide obtained by polymerizing the aromatic polyamide oligomer shown in
We have developed a thermosetting polyamide composition containing the following radical polymerization initiator. This cured aromatic polyamide has the superior chemical properties of traditional aromatic polyamides. The present inventors have discovered that it has excellent characteristics such as excellent mechanical properties, ease of molding, and little decrease in mechanical strength at high temperatures, and have thus completed the present invention. The aromatic polyamide oligomer having a terminal unsaturated group of the present invention can be represented by the following reaction formula as an example. Acrylamidomekphenylenediamine (aromatic diaminoisophthalic acid dichloride (aromatic dicarboxylic acid dihalide)
A hydrogen chloride acceptor is required, and it is generally convenient to use an aliphatic tertiary amine or a caustic alkali. In this case, 11 is from I to 15, and preferably a value of about 3 to 7 is advantageous for ease of moldability, and polymerization at this stage is not particularly necessary. This reaction generally involves placing the amines in the aqueous phase and the acid chloride in an inert T-T which does not dissolve in water.
The interfacial polycondensation reaction can be carried out by mixing the organic solvent with an organic solvent, or the low-temperature solution polycondensation reaction can be carried out by dissolving the two in an inert organic solvent and condensing the mixture at a low temperature. Examples of aromatic diamines that can be used in the present invention include metaphenylenediamine, 4.4"-diaminodiphenylmethane, 4.4"-diaminodiphenylbroban, and 3.
3°-dimethyl-4.4°-diaminodiphenylmethane, 4.4°-diaminodiphenyl ether. 3.4'
-diaminodiphenyl ether, 3.3'-diaminodiphenylsulfone, 4.4°-diaminodiphenylsulfone, dianisidine, 2.4-}-lylenediamine,
2.4/2.6-Toluylene diamine mixture, 1.3-
Bis(3-aminophenoxy)benzene and the like can be used, and it is possible to use a mixture of two types or more.

As the precursor of the organic residue having a terminal unsaturated group, acrylamide and meccrylamide are used. Also, as the aromatic dicarponic acid cyhalide that can be used in the present invention, dichloride of aromatic dibasic acid is convenient, such as Representative examples include terephthalic acid dichloride, isophthalic acid dichloride, phthalic acid dichloride, or mixtures thereof.

The heat resistance of phthalic acid dichloride is slightly insufficient compared to the aromatic polyamides taught here, and when terephthalic acid dichloride is used, the heat resistance of the polymer after heat conversion is sufficient, but as a precursor, The melting point of the aromatic polyamide oligomer used tends to be high, making it difficult to handle, and from a practical standpoint, isophthalic acid dichloride has the best balanced properties and meets the purpose of the present invention. .

This synthesis reaction progresses in a relatively chemical reduction reaction, so the soil for which n in the formula [+1] was calculated, the required amount of (mek)acrylamide, aromatic diamine, and aromatic dicarboxylic acid dihalide are reacted. If precise adjustment is required, the molar ratio can be determined by a simple test. As explained above, the composition of the aromatic polyamide oligomer obtained by this reaction can be easily selected, and it can also be easily molded at a temperature of 200° C. or lower. The aromatic polyamide oligomer having a terminal unsaturated group synthesized according to the present invention can be cured in combination with a radical generating catalyst, making it possible to significantly improve copper thermal properties.

There is no need to limit the radical generation catalyst, as peroxide types are suitable industrially. Narino: ``When the temperature exceeds 100℃, a so-called high-temperature decomposition type, such as dicumyl peroxide type, is used. The amount used is 5 1) hr or less, bf or 1 to 3 p.
hr is appropriate. In addition, the combined use of monomers that can be copolymerized with the unsaturated bonds of aromatic polyamide oligomers is possible when the monomer dissolves the oligomer, and especially when n in the formula IJ is small, the scope of application is wide.

In the present invention, the aromatic polyamide oligomer having a terminal unsaturated group is used as a reinforcing agent, a filler, a releasing agent,
It goes without saying that colorants, other polymers as low shrinkage agents, etc. can be used in combination as necessary.

The composition blended in this way is highly stable at room temperature, and can of course be blended immediately before use.
For a short period of time, use Lr? with a radical-containing initiator.
Possible to store and transport.

And most of the polyamide oligomers are heated to 300°C.
Since it has a melting point of 100% and a lower viscosity than ordinary aromatic polyamides, it can flow in complex shapes before curing. However, once it is polymerized and hardened, it has no melting point or softening point, and only undergoes thermal decomposition, resulting in a polymer whose physical properties are less dependent on temperature. Next, examples are shown below to help understand the present invention. [Example] (Synthesis Example 1) (Hereafter in the margin)
Charge 20.3 g (0.1 mol) of isophthalic acid chloride and 100 g of dimethyl fulumamide (DMF) into a 0rnJ2 four-piece separate flask, and cool to below 10°C. Next, predetermined fa (0.0333 mol) of acrylamide or methacrylamide, predetermined i (0.0833 mol)
of aromatic diamine, triethylamine 20.2g (0
．． 2 moles). Weigh and mix DMFIOOg (or 80g) and drop it into the reaction flask. [If 80g of DMF is used, wash the dropping funnel with 20g of DMF after the dropwise addition, and drop the washing liquid into the reaction flask. J During this period, keep the reaction temperature below 10°C.After the completion of drop F, keep the temperature of the reaction mixture below 10°C,
hr. Continue stirring. Next, the reaction mixture is gradually added to a large amount of water with vigorous stirring to precipitate crystals. Warm and filter the precipitated crystals, wash with water, and dry.
(Example 1) Parts by weight of Ligomer [7JI obtained in Synthesis Example 1 and lffi parts of dicumyl peroxide (2% acetone solution) were added to a test tube, the temperature was gradually raised, and the acetone was blown off to dry.
Then, when the mixture was cured at ambient temperature of 200° C. for 7 hours, an amber-colored, durable, insoluble and infusible bulk polymer was obtained.
The resulting polymer was crushed in a mortar and thermogravimetrically analyzed in air at a heating rate of 10°C/min.
). 95% weight retention temperature 304°C 90% weight retention temperature 423°C 500°C Weight retention 74.4% (Example 2) The same procedure as in Example 1 was performed except that the synthesized oligomer [II] was used. Thermogravimetric analysis of the obtained polymer revealed the results as shown in (2) in Figure 1.

95% weight retention temperature 305°C 90% ν retention rate temperature 387°C 500°C Weight retention 72.3% (Example 3) The same operation as in Example 1 was carried out except that the synthesized oligomer [II+] was used.

Thermogravimetric analysis of the obtained polymer revealed (3) in Figure 1.
It became like this.

95% weight retention temperature 317°C 90% weight retention temperature 408°C 500°C Weight retention 72.0% (Example 4) Synthesized in Synthesis Example 4 instead of Ligomer [I] synthesized in Synthesis Example 1 The same procedure as in Example 1 was performed except that oligomer [IV] was used. Thermogravimetric analysis of the obtained polymer gave the following results. 95% weight retention temperature 323°C 90% weight retention temperature 426°C 500°C Weight retention 73.5% (Example 5) Synthesized in Synthesis Example 5 instead of Ligomer [1] synthesized in Synthesis Example 1 Example 1 except that ligomer [V] was used.
I did the same repeat.

When the obtained polymer was subjected to thermogravimetric analysis, the following tj results were obtained.

95% weight retention temperature: 30 1"c 90% weight retention temperature: 418°C 500°C: weight retention rate: 73.8% (Example 6) 100 parts of the acid oligomer [1] synthesized in Synthesis Example 1 and dicumyl bar acid 2 parts to 1 part dimethylformamide
After immersing a glass cloth in a solution dissolved in 0.0 parts, 1
Bibreg was prepared by drying at 00°C for 1 hour. After that, a few of these bliblegs were put together and the pressure was 15 kg.
/ c+m". After heating and pressure forming at a temperature of 180°C for 1 hour, a laminate was obtained by curing at 200°C for 5 hours. The bending strength of this laminate was 43 kg/open 2 at 25°C.
Met. The bending strength after heating at 230°C for 200 hours was 54κg/mtn2 at 25°C. [Effect 1] Among the engineering plastics that have been developed one after another recently, there is a group of aromatic polyamides called aramids. This group consists of resins that have a higher melting point, higher hardness, and higher strength than conventional thermoplastic resins, and some resins do not have a melting point that makes processing and moldability extremely difficult.
Since it is essentially a thermoplastic, it was unavoidable that its hardness and mechanical strength would decrease at high temperatures. The present invention has been carried out with the aim of developing a heat-resistant resin that has excellent processability, hardness and mechanical strength at high temperatures, and is obtained by curing an aromatic polyamide oligomer having an unsaturated group at the end. The objective was achieved by developing a thermosetting aromatic polyamide. In history, we developed a composition suitable for obtaining this aromatic polyamide, and dramatically improved the moldability of aromatic polyamide.

[Brief explanation of the drawing]

FIG. 1 shows the results of thermal mass analysis of the composites obtained in Examples 1 to 3.

Claims (2)

[Claims] (1) General formula▲There are mathematical formulas, chemical formulas, tables, etc.▼...[I] [However, in the formula, R is H or CH_3, R_1 and R_
2 is a group selected from divalent aromatic groups, and n is 1 to 1
Represents the number 5. ] A thermosetting polyamide obtained by polymerizing the aromatic polyamide oligomer shown below. (2) A thermosetting polyamide composition comprising an aromatic polyamide oligomer represented by the general formula [I] according to claim 1, to which 5% by weight or less of a radical polymerization initiator is added.