JPH0220645B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a curable resin composition comprising a polymer substance having a crosslinkable functional group in a rigid polymeric main chain and a thermosetting resin having a polymerizable crosslinkable functional group, and The present invention relates to a cured molded article having excellent mechanical properties and heat resistance obtained by curing. [Prior art] Polymers with rigid main chains include para-bonded aromatic polyamides such as paraphenylene terephthalamide (PPTA), polyimides such as paraphenylenepyromellitimide, polyphenylenebenzthiazole, and polyphenylene benzthiazole. Heterocycle-containing polymers such as phenylene benzoxazole and polyphenylene imidazole are well known as high-performance polymers. However, because the main chains of these polymers are so rigid, the temperature at which the molecular chains can move (Tg: glass transition temperature, Tm: melting point) is higher than the thermal decomposition temperature of these polymers, so they are usually It is difficult to obtain molded articles because melt molding, which is the method used to mold polymers, is not possible, and these rigid polymers are usually used in the form of films or fibers. Further, even when a molded body is obtained, the molding method is a special molding method, and the mechanical properties of the molded body are not necessarily excellent. On the other hand, thermosetting resin cured molded products containing maleimide groups as polymerizable functional groups obtained by the reaction of amines and maleic anhydride not only exhibit excellent heat resistance due to the contribution of imide groups, but also exhibit excellent heat resistance due to the contribution of imide groups. Since the polymerization and curing reaction is an addition reaction, no volatile components are produced, so it is attracting attention (Japanese Patent Publication No. 20625/1983). However, because maleimide resin undergoes a three-dimensional crosslinking reaction through radical polymerization to form a high-density network structure, it suffers from large thermal contraction during curing, and the cured molded product is brittle. Since it has poor mechanical properties, such as being prone to cracks, various improvements have been made. For example, by creating a curable composition of bismaleimide resin and diamine, mechanical properties have been improved without reducing heat resistance (French Patent No. 1555564). In addition, compositions such as epoxy resins and polyfunctional allyl ester resins have also been studied (JP-A-53-2190, 54-10595, 53-2191, 52
-19598, 52-19599, 48-19238, 49-12600). Furthermore, compositions of polymeric substances such as polysulfone and bismaleimide resins have also been studied (Japanese Patent Application Laid-Open No. 47-5037). Further, it is well known that certain diacetylene compounds are polymerized in a crystalline state by heat and high energy rays such as γ rays or ultraviolet rays (topochemical polymerization). Regarding diacetylene, research has mainly focused on diacetylene compound monomers, and although there are some reports on polymers containing diacetylene groups, there are few examples of such research (Makromol.Chem.) 134 219 (1970 ), Journal of Polymer Science, Polymer Chemistry Editions (J.Polym.Sci.Polym.
Chem.Ed.), 19 1154 (1981). The present inventors have focused on the above-mentioned properties of diacetylene groups, and have synthesized novel polymers containing diacetylene groups for the purpose of obtaining molded articles with excellent mechanical properties. We have studied polymer molded products that have high mechanical properties by high-pressure molding in a solid state below the decomposition temperature or below the melting temperature. [Problem to be solved by the invention] A polymer with a rigid main chain is a high-performance polymer with excellent mechanical and thermal properties, but it is difficult to obtain a molded product and has poor moldability. . The present inventors have proposed that a rigid polymer can be molded into a molded product by introducing diacetylene groups into the polymer main chain, but since high pressure is used in the molding conditions, the molding equipment and molding tool are There were restrictions on the mold and shape of the molded product. Further, although maleimide resin has a high degree of heat resistance and excellent moldability, its cured molded product is brittle. [Means to solve the problem] In recent years, in the field of thermosetting resins, IPN
Composite materials with a (Interpenetrating Polymer Networks) structure are attracting attention. Unlike conventional polymer blends and graft polymers, this is characterized by the fact that two types of polymer main chains intertwine and form an entangled network structure. By adopting an IPN structure, two types of polymer main chains become intertwined, increasing mutual compatibility between polymers.
It increases crosslink density, refines the phase structure, and increases interlayer adhesion, resulting in excellent mechanical properties, chemical resistance, and heat resistance that cannot be obtained with a single polymer. The present inventors have conducted intensive studies to improve the mechanical properties and moldability of diacetylene polymers without impairing their high rigidity and heat resistance. By using a curable resin composition consisting of a rigid polymeric material having a diacetylene group as a base and a maleimide resin, we succeeded in further improving the moldability without impairing mechanical properties, and achieved the present invention. That is, the present invention provides a curable resin composition comprising a rigid polymeric substance having a diacetylene group as a crosslinkable functional group in the polymeric main chain and a maleimide resin, and a curable resin composition obtained by curing the composition. The present invention provides a cured molded product having a flexural modulus of 6 GPa or more. The rigid polymer having a diacetylene group as a crosslinkable functional group of the present invention is an aromatic polymer in which all of its bonds are para bonds, and in molecular model, it is a rod-shaped polymer that does not bend. The diacetylene group used as a crosslinkable functional group is also a non-bent crosslink unlike an ethylenic crosslink, and is a crosslinkable functional group that strengthens the rigidity of the main chain of the polymer. Specifically, it contains a structural unit represented by the following general formula (1) or/and (2). (In the formula, Ar ₁ , Ar ₂ , Ar ₃ , Ar ₄ have carbon numbers from 6 to
24 divalent para-bonded aromatic hydrocarbon groups are shown.
R ₁ and R ₂ represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. ) These divalent para-bonded aromatic hydrocarbon groups represented by Ar ₁ to _{Ar 4} have the following structural formula, and these aromatic hydrocarbon groups include aliphatic hydrocarbon groups, ether groups, thioether They may be bonded by a carbonyl group, a sulfone group, an ester group, an amide group, a urethane group, an azomethine group, or the like. Further, the hydrogen atom of the aromatic hydrocarbon group may be substituted with a halogen group, a hydrocarbon group, or the like.

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R ₁ and R ₂ are hydrogen or a monovalent hydrocarbon group having 1 to 12 carbon atoms. Examples _of hydrocarbon groups include _-CH3 , _{-C2H5 , -C3H7} , _{-C4H9 ,}

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〔Production method〕

The method for producing the first component, a polymer having a diacetylene group, is exemplified by the following two methods. The first method is a reaction between a diamine monomer containing a diacetylene group and a dicarboxylic acid derivative (reaction formula below), a reaction between a diamine monomer and a dicarboxylic acid derivative containing a diacetylene group, or a diamine containing a diacetylene group. It is produced by the reaction of monomers with dicarboxylic acid derivatives containing diacetylene groups. (In the formula, X is a halogen group, a hydroxyl group, or an alkoxy group. _{R 1} , R ₂ and Ar ₁ , Ar ₂ , Ar ₄ are
Same as (1) and (4). ) In the second method, a bisacetylene group compound is produced by an oxidative coupling reaction in the presence of a catalyst. The maleimide resin represented by formula (3) is produced by reacting a polyvalent amine compound and a maleic anhydride derivative. The composition of the present invention of a rigid polymer containing a diacetylene group and a thermosetting resin having an ethylenic functional group can be produced by a commonly used method such as an extruder, a Brabender, a roll, etc. Melt blending using a blender, dry blending using a mixer, etc. are inappropriate. Since the Tg and Tm of the diacetylene group-containing rigid polymer of the present invention are higher than the thermal decomposition temperature, melt blending is inappropriate, and dry blending using a mixer etc. produces a very macroscopic blended state and is non-uniform. Therefore, it is inappropriate. The optimal method for producing the composition of the present invention of a rigid polymer containing a diacetylene group and a maleimide resin is a solution blending method in which both are mixed as a homogeneous solution. That is, this is a method in which a rigid polymer containing a diacetylene group and a maleimide resin are dissolved in a common good solvent, and the solution is poured into a common poor solvent to co-precipitate. As common good solvents, aprotic polar solvents such as N-methylpyrrolidone, dimethylacetamide, dimethylformamide, and hexamethylphosphoramide are used. These solvents may be used alone or in combination. Further, salts such as lithium chloride and calcium chloride may be present in these solvents. Common poor solvents used to precipitate the curable resin composition by introducing the curable resin composition solution include alcoholic solvents such as methanol and ethanol, aliphatic solvents such as hexane and heptane, and water. . The amount of poor solvent used is 2 to 10 times the amount of good solvent. The precipitated solid is filtered,
The curable resin composition of the present invention is obtained by separating by a method such as centrifugation and drying. The ratio of rigid polymer material and thermosetting resin is
The thermosetting resin is used in an amount of 5 to 900 parts by weight, preferably 10 to 500 parts by weight, per 100 parts by weight of the rigid polymeric material. [Molding method] The curable resin composition of the present invention can be easily molded by filling it into a mold and heating it. Heat curing temperature is 150℃~350℃
is within the range of If it is below 150°C, it takes a long time to cure and is not economical, and if it is above 350°C, the curing reaction becomes too fast and is difficult to control. The curable resin composition of the present invention can be cured under relatively mild conditions, and the resulting cured product has excellent mechanical properties and is an insoluble and infusible material with excellent heat resistance. It provides a heat-resistant polymer material. The curable resin composition of the present invention is useful as a molding resin by incorporating inorganic fillers, flame retardants, pigments, etc. Further, the curable resin composition of the present invention is useful as a varnish for impregnation, lamination, adhesion, and film by making it into an organic solvent solution (varnish). A curable resin composition comprising a rigid polymer substance having a diacetylene group as a crosslinkable functional group in the polymer main chain of the present invention and a thermosetting resin having an ethylenic functional group can be cured. The cured molded product with the IPN structure has a flexural modulus of 6 GPa or more, high strength, and excellent mechanical properties. In addition, the heat distortion temperature is 250°C or higher, and it has excellent heat resistance. In addition, it can be molded using the same molding methods as ordinary thermosetting resins, and has excellent moldability as it can be molded into any shape. As described above, the cured molded product of the present invention has excellent mechanical properties, heat resistance, moldability, etc., and is therefore useful as a material for parts that require high performance, such as aerospace materials, precision mechanical parts, and electronic materials. . [Example] Next, the present invention will be described in more detail with reference to Examples. Reference example 1 Para-amide diacetylene polymer ()
Production of [PA (p-APBI/TP)] A solution of 23.2 parts of 4,4'-diaminodiphenylbutadiyne dissolved in 1000 parts of dry N-methylpyrrolidone containing 10% lithium chloride was cooled to 0 DEG C., and 20.3 parts of sphthalic acid chloride was added in powder form. The reaction temperature was raised to room temperature for 1 hour at 0℃ and then for 2 hours.
A para-amide diacetylene group polymer () solution was prepared by reacting for a period of time. Reference example 2 Para-amide diacetylene polymer ()
Production of [PA (p-PDA/P-CPBI)] Same as Reference Example 1 except that paraphenidiamine was used instead of 4,4'-diaminodiphenylbutadiine and 4,4'-dichloroformylphenylenebutadiine was used instead of terephthalic acid chloride. A para-amide diacetylene polymer () solution was prepared. Reference example 3 Meta-amide diacetylene polymer [PA (m
-ABPI/i-PT)] production In Reference Example 1, 3,3'-diaminodiphenylbutadiine was used instead of 4,4'-diaminodiphenylbutadiine, dry N-methylpyrrolidone was used as the solvent, and isophthalic acid was used instead of terephthalic acid. A meta-amide diacetylene polymer solution was produced in the same manner as in Reference Example 1 except for this. Example 1 N,N'-4,'-diphenylmethane bismaleimide [DDM-BMI]36 was added to the para-amide diacetylene polymer () solution produced in Reference Example 1.
of the mixture and stirred well. PA (p-APBI/TP), DDM
- BMI was co-deposited. After filtering the precipitate,
Washed twice with water and twice with methanol, 60℃ under reduced pressure.
I let it dry for a day and night. The obtained composition was filled into a mold, pre-cured at 200°C for 2 hours using a hot press, taken out from the mold, and further post-cured at 250°C for 5 hours. The cured molded body was processed using Autograph DSS-500 manufactured by Shimadzu Corporation.
When a bending test was conducted using
It had a flexural modulus of 170 MPa and a flexural modulus of 7.7 GPa. Example 2 The molded article obtained in Example 1 was further post-cured at 300°C for 5 hours. Bending strength of the obtained compact
It had a flexural modulus of 150 MPa and a flexural modulus of 7.3 GPa. Examples 3 to 6 PA (p-APBI/TP) of Example 1, DDM-
A cured molded product was obtained by changing the composition ratio of BMI and curing conditions. The mechanical properties of the cured molded product are shown in the table. Examples 7 to 8 A molded article was produced in the same manner as in Examples 1 and 2, except that the para-amide diacetylene polymer () solution produced in Reference Example 2 was used instead of the para-amide diacetylene polymer () solution of Example 1. I got it. The mechanical properties of the cured molded product are shown in the table. Comparative Example 1 N,N'-4,4'-diphenylmethane bismaleimide (DDM-BMI) was heated to 170°C to melt it, poured into a mold, and cured at 200°C for 5 hours. The cured molded product had many cracks and could not be used for measuring mechanical properties. Comparative Example 2 The PA (p-APBI/TP) solution produced in Reference Example 1 was poured into methanol with vigorous stirring, and the PA (p-APBI/TP) solution was poured into methanol with vigorous stirring.
-APBI/TP) was isolated. This diacetylene group-containing polymer can be molded under high pressure conditions of 5,000 atmospheres or more, but under normal pressure, the polymer powders do not fuse together and are in a disjointed state, making molding impossible. Comparative Examples 3 to 4 Implemented except that the polymer containing diacetylene groups was changed from a rigid para-based polymer [PA (p-APBI/TP)] to a meta-based polymer [PA (m-APBI/i-PT)] A cured molded product was obtained in the same manner as in Examples 1 and 2. The mechanical properties of the cured molded product are shown in the table. In this way, when a rigid polymer is not used, the flexural modulus is
It is less than 6 GPa and does not have high mechanical properties.

【table】

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Claims (1)

[Scope of Claims] 1. A rigid polymer substance having a diacetylene group represented by the following general formula (1) or/and (2) as a crosslinkable functional group in the polymer main chain, and the following general formula (3). ) A curable resin composition comprising a maleimide resin represented by: (In the formula, Ar ₁ , Ar ₂ , Ar ₃ , Ar ₄ have carbon numbers from 6 to
24 divalent para-bonded aromatic hydrocarbon groups are shown.
R ₁ and R ₂ represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. ) (In the formula, R ₅ represents an m-valent hydrocarbon group having 6 to 18 carbon atoms. R ₃ and R ₄ represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. m is 2 (indicates an integer of the above) 2 Flexural modulus which is a curing reaction product of a maleimide resin and a rigid polymeric substance having a diacetylene group in the polymeric main chain described in claim 1.
Cured molded product of 6GPa or more.