JPS63248828A - Imide oligomer resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition of excellent storage stability, moldability and heat resistance, to be used in composite materials and adhesives by adding 2 different kinds of oligomers, resulting from reactions of an aromatic tetracarboxylic acid or its derivative and a polyamine with different kinds of agents to activate chain terminals respectively. CONSTITUTION:The subject composition is obtained by mixing (A) an imide oligomer resulting from the reaction of nadic acid with an aromatic tetracarboxylic acid or its derivative such as pyromellitic acid and a polyamine from o-ethylaniline and formaldehyde in an organic solvent such as N,N- dimethylformamide and (B) another imide oligomer from the reaction with maleic acid at an A:B equivalent ratio of 60:40-10:90.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an organic solvent-soluble imide oligomer composition having excellent storage stability and moldability.
The object of the present invention is to provide a precursor that can be self-cured by heat without producing volatile components such as alcohol, and can be converted into a polyimide resin with good heat resistance. In particular, the present invention relates to an imide oligomer resin composition suitable for producing a fiber-reinforced composite material with good heat resistance, which uses glass fiber, aramid fiber, carbon fiber, silicon carbide fiber, etc. as a reinforcing material.

[Prior art]

Pyromellitic dianhydride (PMDA) or 3,3
', ¥1llt'-benzophenonetetracarboxylic dianhydride (BTI) A) or these acids, lower alkyl '
It is already known that polyimide resins with good heat resistance can be obtained by reacting derivatives such as polyesters with aromatic diamines. In general, these polyimides are insoluble and infusible and have extremely poor moldability, so to mold them, moldable precursors such as polyamic acids or polyamide esters are used, and two methods are used: After molding, imidization is performed. At this imidization stage, volatile components such as water and alcohol are produced, so if this process is applied to a fiber reinforced composite material, defects such as voids are likely to occur, which is undesirable.

In addition, solutions of polyamic acid, polyamide ester, etc. have high viscosity and require a high boiling point solvent such as an amide solvent, making it difficult to impregnate reinforcing fibers and remove the solvent, making it difficult to make prepregs. . Furthermore, these polyamic acids,
Precursors such as polyamide esters have poor stability, and prepregs obtained from them cannot be stored for long periods of time.

U.S. Pat. No. 3,7,1419 discloses a method for producing polyimide applicable to fiber-reinforced composite materials, including L-kill esters, aromatic diamines, and unsaturated polyimides. This method makes it easy to produce prepregs because the solution has a low viscosity, but the prepregs are not sufficiently stable and require low temperatures for long-term storage. Furthermore, during molding, a one-step reaction is required to generate an imide oligomer, which is a precursor of polyimide, and then to harden the imide oligomer by increasing its molecular weight. At this time, water and alcohol are generated as volatile components, which can cause defects. It's easy to become. Although the cured product has good heat resistance, the curing temperature is relatively high at around 300°C, and there are restrictions on molding equipment, auxiliary materials, etc.

Therefore, the present inventors have improved these drawbacks by creating a solvent-soluble imide oligomer that has excellent storage stability, does not generate volatile components such as water and alcohol during molding, and can be converted into a polyimide that has good heat resistance when heated. We have previously reported on the manufacturing method (Japanese Unexamined Patent Application Publication No. 67-671). Furthermore, it has become possible to produce fiber-reinforced composite materials with excellent thermal and mechanical properties using such imide oligomers.

[Problem that the invention seeks to solve]

However, the current situation is that these fiber-reinforced composite materials are required to further improve various properties such as formability, mechanical strength, and heat resistance. As a result of intensive research into improving imide oligomers,
Specifically, an object of the present invention is to provide a solvent-soluble imide oligomer composition that can be cured at a relatively low temperature and the cured product can exhibit high heat resistance. This purpose is achieved by reacting an aromatic tetracarboxylic acid or a derivative thereof, a polyamine which is a condensation product of 0-ethylaniline and formaldehyde, and a terminal functionalizing agent as essential components. In the resin composition consisting of B), the imide oligomer + AJ is an imide oligomer having a nadic acid residue connected by an imide bond as a terminal functional group, and the imide oligomer (B) is an imide oligomer having a nadic acid residue connected by an imide bond as a terminal functional group λt. An imide oligomer resin composition which is an imide oligomer having a maleic acid residue, and is characterized in that the equivalent ratio of the imide oligomer (B) to the imide oligomer (B) is OtsuθNigeQ~/θ:9θ. easily achieved by

The imide oligomer resin composition of the present invention is a condensate of aromatic tetracarboxylic acid or its derivative, 0-ethylaniline, and formaldehyde, and contains acetic acid, s, 3', <t, <t
'-diphenyl ether tetracarboxylic acid, s, 3',
y, et-biphenyltetracarboxylic acid, 2. ! , B,
7-naphthalenetetracarboxylic acid, core 3. J-thiophenetetracarboxylic acid, 3°. These aromatic tetracarboxylic acid components can be used in the form of derivatives such as lower alkyl esters and dianhydrides, but it is preferable to use dianhydrides due to their reactivity.

The polyamine used in the present invention is a condensate of 0-ethylaniline and formaldehyde.

As described in Japanese Unexamined Patent Application Publication No. 17-3/9, No. 2003, the component 3 is reacted with a strong inorganic acid such as hydrochloric acid or sulfuric acid in an aqueous medium at 0 to 700°C. In addition to 3'-diethyluk's diaminodiphenylmethane, triamine, tetramine, etc. are produced as by-products. The diamine component can be easily obtained by separating these by distillation, but in the present invention, these by-products can be used in the production of imide oligomers without being separated. However, if the amount of polyamines greater than triamine increases, gelation tends to occur during oligomer production, so the amount of polyamines should preferably be 70% by weight or less! It is preferable to use one with a θ weight of 8% or less.

Also, by adding aniline during the condensation reaction between 0-ethylaniline and formaldehyde, 3.3'-diethyluk, y'-diaminodiphenylmethane, 3-ethyl-4t, a'-diaminodiphenylmethane, g, p'-
A mixture of three diaminodiphenylmethane components is obtained, which can also be used effectively in the present invention. Instead of aniline, a condensate of 0-ethylaniline to which an aniline derivative without a substituent at the p-position, such as 0-toluidine or 0-chloroaniline, is added can also be used. Furthermore, other diamines can be used in place of a part of the condensate of 0-ethylaniline within the range in which the imide oligomer to be produced is soluble in the organic solvent. As the diamine, for example, the formula H2N -R-N
H2 (where R is a covalent group having up to 30 carbon atoms and may also optionally contain oxygen, sulfur, nitrogen, silicon, phosphorus and similar inert groups) ). Preferred examples of R include linear or branched alkylene groups, cycloalkylene groups, monocyclic or polycyclic aromatic groups, and multiple cycloalkylene groups bonded via direct carbon bonds or covalent linking groups. , aromatic groups, etc. As a covalent linking group, 10-1-so2-1-8-1-〇〇 +, /~
An alkylene group having three carbon atoms (excluding a condensate of 〇-ethylaniline and formaldehyde), etc. Seven or more of these diamines are used in place of a part of the 〇-ethylaniline condensate, but the amount used is usually within the total amount of diamines. It is more than θ morti.

Nadic acid (ternorbornene-
It is essential to use two unsaturated dicarboxylic acids: λ,3-dicarboxylic acid (El) and maleic acid.

In the present invention, using such terminal functionalizing agents, imide oligomers <A) and CB+ whose terminal terminals are nadic acid residues and maleic acid residues, respectively, are prepared in an equivalent ratio of O:4 to 10:90. It is important to have a range. If this equivalence ratio is larger than the above range, the reactivity will decrease and a high molding temperature will be required, and if this ratio is too small, the heat resistance of the cured product will decrease, which is not preferable.

These types of unsaturated dicarboxylic acids can also be used in the form of anhydrides and derivatives such as low alkyl esters, and from the viewpoint of reactivity, it is preferable to use them in the form of anhydrides.

Imide oligomer (A) and (
B) is soluble in organic solvents. Therefore, an imide oligomer can be easily obtained by reacting an aromatic tetracarboxylic acid component, a polyamine component, and a terminal functionalizing agent component in a solvent.

The resin composition of the present invention can be obtained by producing two types of imide oligomers using respective terminal functionalizing agent components and mixing them in predetermined amounts.

N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2 as a solvent used in the reaction
- An imide oligomer can be easily obtained by reacting an amide such as pyrrolidone in the presence of an imidization catalyst and a dehydrating agent depending on the need for dissolution.

These aromatic tetracarboxylic acids, polyamines, terminal functionalizing agents? The proportions of the components are appropriately determined depending on the purpose and in relation to physical properties. When the polyamine is a diamine, the molar ratio of each component is generally -,' n / (n + /
) / 2, but this ratio is not necessarily exact. That is, in order to reliably introduce the terminal functional group, an OT function is to use an excess amount of the terminal functionalizing agent and to purify and remove the excess after the reaction. (Since the molecular weight of the imide oligomer to be produced is determined by the value of n, the molar ratio of tetracarboxylic acid/diamine should be strictly controlled. The value of n is /~/! However, as the value of n increases, the molecular weight of the oligomer produced increases, and the viscosity of the solution increases, making it difficult to manufacture prepregs. The molecular weight is preferably 600θ or less.

': Go) The solubility differs depending on the product, but in addition to the ether solvents used in the synthesis of imide oligomers, ketones such as acetone and methyl ethyl ketone, and ethers such as tetrahydrofuran, dioxane, and 1-xyethane. , methylene chloride, /, halogenated solvent such as λ-dichloroethane 1
(Also dissolves.

, two types of imide oligomers can be easily mixed by dissolving them in these solvents.

These solutions have low viscosity, have good impregnating properties into reinforcing fibers, and are easy to manufacture into prepregs. Prepreg is usually produced by immersing reinforcing fibers in a melting agent having a weight of 20 to 000, followed by drying. Since the obtained prepreg has already been imidized, it has excellent storage stability, and since volatile components such as water and alcohol are not generated during molding, there is little photo-production of defects and good mechanical properties. In addition, it is possible to obtain a fiber-reinforced composite material that has excellent heat resistance.

The imide oligomer constituting the resin composition of the present invention has an aromatic polyimide skeleton with good heat resistance in the main chain, and two types of self-curing crosslinking groups at the terminals, such as diallylphthale-1, triallyl in cyanurate, It is easy to mix reactive diluents such as 7'-bis(coallylphenol)dimethylmethane and divinylbenzene, carbon powder, various metals, metal oxides, silica, asbestos, etc., and only fiber-reinforced composite materials can be used. It can be used to produce adhesives, coating materials, molded products, etc. with good heat resistance.

〔Example〕

Hereinafter, the imide oligomer resin composition of the present invention will be specifically illustrated by Examples, but the present invention does not exceed the scope of the claims.
Unless otherwise specified, it is not limited to this.

The curing reaction was carried out at 2j'θ°C for 7 hours, and then in the open at 27θ°C/hour, 290°C/hour, and further for 3 hours.
Curing was performed after 20°C g hours.

Further, the glass transition temperature (Tg) was determined from the change in the thermal expansion curve by the TMA method.

In addition, an imide oligomer having a nadic acid residue connected with an imide group as a terminal functional group is a nasiimide-terminated imide oligomer, and an imide oligomer having a maleic acid residue connected with an imide group as a terminal functional group is a maleimide-terminated imide oligomer. Abbreviated as oligomer.

Reference example/Synthesis of nasiimide-terminated imide oligomer (1
) Z-shaped flasks K and O equipped with stirring barrels, thermometers, and distillation tubes
- Ethylaniline/formaldehyde condensate (manufactured by Nippon Kayaku Co., Ltd., trade name Kayano-de A-A) f: J', J''-diethyluke obtained by distillation under reduced pressure.

y'-diaminodiphenylmethane (boiling point 1.2g 2℃/
≦, Hg) 10.22 (θ, gθ moles) and 100 f of N-methyl-λ-pyrrolidone (NMP) were added and uniformly dissolved at room temperature. Then 3.3',\,'I'-benzophenonetetracarboxylic dianhydride (BTDA) 6;
the law of nature? (0.20 mol) in NMP! 01 and added to the above diamine solution.

After stirring at room temperature for 7 hours, nadic anhydride (NA)? 2,2
? (θ, 4t¥mol) was added to produce an amic acid oligomer. After stirring at room temperature for an additional hour, the temperature was gradually raised in an oil bath, and the imidization reaction was carried out at 200° C. for 2 hours.

After the reaction is complete, cool to around room temperature to obtain a homogeneous reaction solution! The imide oligomer was precipitated by pouring it into 3 tons of tibiridine aqueous solution. After separating the precipitated imide oligomers from door to door, 2 tons of carbon water and 3 tons of
After dispersion and washing, the mixture was vacuum dried at 700° C. for 20 hours. The yield was almost quantitative.

The engineered R spectrum of the nasiimide-terminated imide oligomer with a number average molecular weight of 1090 is /7♂0.220α-
Absorption due to the imide group of 1 was obvious. or,
The generated imide oligomer is methyl ethyl ketone (ME
K), tetrahydrofuran (THII'), N, N-
It was dissolved in dimethylformamide (DMII') at a concentration of 30% by weight or more.

Reference example: Synthesis of nashiimide-terminated imide oligomer (2)
) Reference example / BTDA & 4ty, NA72.2f instead of BTDA Jj, ri? (0.27 mol), NAzo♂
.

Reference Example 3 Synthesis of maleimide-terminated imide oligomer (1
) Maleic anhydride (M
A) 4t3. /f (0.4t4t mol), an amic acid oligomer was produced in the same manner as in Reference Example/. Acetic anhydride/1L3f as a dehydrating agent and sodium acetate/2S' as an imidization catalyst were added to the generated amic acid oligomer, and an imidization reaction was performed at 20° C. for 7 hours.

After cooling to room temperature, the sodium acetate was removed in a furnace, and the resulting homogeneous solution was poured into 3 tons of water to precipitate an imide oligomer. The precipitated imide oligomer was dispersed in water again after being distributed from house to house, and neutralized with sodium bicarbonate. After being sent to each house, it was washed by dispersing it in 3 tons of carbonated water and vacuum-dried at 50° C. for 50 hours.

The yield was almost quantitative.

The obtained maleimide-terminated imide oligomer R spectrum and solubility having a number average molecular weight of 960 were almost the same as those of Reference Example.

Reference example: Synthesis of gmaleimide-terminated imide oligomer (2)
) Reference example/BTDA 4g, 4t1, NA';#, J
``Instead of f, BTDA♂L9 F (0.27 mol),
MA girl, / ? (0.29 mol) and in substantially the same manner as in Reference Example 3, a maleimide-terminated imide oligomer having a number average molecular weight of 00 was obtained.

Example/ The cured product had a Tg of 330°C.

Example 2 Imide oligomer of Reference Example 70.0, imide oligomer of Reference Example 3? ,! Using /f, equivalent ratio =! in the same manner as in Example/. 0/! An imide oligomer resin composition of θ was obtained. The Tg of the cured product of this resin composition is 3! It was ℃.

Example 3 Imide oligomer io, ot of Reference Example 2, imide oligomer of Reference Example 3/L7? An imide oligomer resin composition having an equivalent ratio of 30,770 was prepared in the same manner as in Example. The Tg of the cured product of this composition was 3/3°C.

Example Z Imide oligomer of Reference Example 2 10. θ2, imide oligomer 2/ of reference example G,! An imide oligomer resin composition having a ratio of -3θ/2θ was obtained in the same manner as in Example 1 using F. The Tg of the cured product of this resin composition was 309°C.

An imide oligomer resin composition with an equivalent ratio of -7θ/3θ was obtained in the same manner as in /. This resin composition was cured, but curing at 2jθ° C. for a time of 30 minutes resulted in insufficient curing, and blisters due to foaming occurred during post-curing in an oven.

Comparative Examples 3 and 3 The imide oligomers of Reference Examples 3 and 3 were cured in the same manner as in Example 1, and the Tg was measured. Each Tg
were 3θθ°C (Comparative Example 2) and 27g°C (Comparative Example 3).

〔Effect of the invention〕

The resin composition of the present invention has excellent storage stability and moldability, and can be used to produce fiber-reinforced bonding materials, adhesives, coating materials, molded products, etc. with good heat resistance.

Director of Industrial Technology Agency

Claims (1)

[Claims] (1) Imide oligomer (A) and imide oligomer (B) obtained by reacting an aromatic tetracarboxylic acid or its derivative, a polyamine which is a condensation product of O-ethylaniline and formaldehyde, and a terminal functionalizing agent as essential components. ), the imide oligomer (A) is an imide oligomer having nadic acid residues connected by an imide bond as a terminal functional group, and the imide oligomer (B) is an imide oligomer having a nadic acid residue connected by an imide bond as a terminal functional group. An imide oligomer having a maleic acid residue, and comprising an imide oligomer (A) and an imide oligomer (B).
), the imide oligomer resin composition having an equivalent ratio of 60:40 to 10:90.