JPH0586793B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a novel polyimide having a curable spiroacetal ring that has excellent thermal stability, flexibility, solubility in solvents, etc. [Prior Art] In recent years, as electronic components have become smaller and lighter and have higher performance, there has been a remarkable tendency for higher performance to be required of plastics used in these fields. Plastics used in this field include phenolic resins, epoxy resins, polyester resins, polyimide resins, etc., but all of these have drawbacks and are not satisfactory. For example, phenolic resins are insufficient in terms of heat resistance, flexibility, and electrical properties, and epoxy resins and polyester resins lack heat resistance and pose problems in the soldering process. Furthermore, although polyimide resins such as Kapton have excellent heat resistance, since they are condensation polymers, they tend to generate voids and have insufficient dimensional stability. In order to improve these problems, research on addition reaction crosslinked polyimides is active. For example, maleimide resins such as methylene dianiline bismaleimide do not generate voids and are relatively easy to cure compared to the polyimides mentioned above. In addition, the polyimide with a terminal nadzic acid type developed by NASA has a heat resistance that can withstand use at 600°C [Applied Polymer Symposium 22, No. 89-100]
Page (73), US Pat. No. 3,745,149]. However, these addition reaction crosslinked imide resins
Both methods require heating at high temperatures and for a long period of time in order to be completely cured, and the resulting cured products are also brittle. Polyimide having a spiroacetal ring has been proposed to improve these drawbacks, but (Japanese Unexamined Patent Publication No. 185784/1984) the glass transition temperature of the cured product is 200°C, and a heat-resistant resin is required. It was wanted. [Means for Solving the Problems] The present invention overcomes the drawbacks of conventional polymaleimide resins and provides a resin with improved thermal stability and flexibility.
The aim is to develop void-free resin. The above object is achieved by using a polyimide having the specific structure shown below. That is, the present invention provides a novel polyimide exhibiting excellent properties represented by the following general formula ().

[ka] (In the formula, Z is

[Formula] or

[Formula], n is an integer of 1 to 6, and m is an integer of 1 to 10. ) The polyimide represented by the general formula above has a softening point of 100.
DMF (N,N-dimethylformamide) above ℃
It is a white powder that is soluble in polar organic solvents such as NMP (N-methylpyrrolidone) and NMP (N-methylpyrrolidone), and it produces a tough cured product that is three-dimensionally crosslinked by thermal polymerization or addition polymerization. The polyimide of the present invention is represented by the following formula (), 3,9-bis(3-aminoalkyl)-2,
It can be easily synthesized by reacting 4,8,10 tetraoxaspiro[5,5]undecane with aromatic tetracarboxylic dianhydride and maleic anhydride.

[Formula, n represents an integer of 1 to 6] The aromatic tetracarboxylic dianhydride used in the present invention has the following general formula ();

[ka] [Z

[Formula] or

[Formula] is shown. ] Pyromellitic dianhydride and 3,3′,
4,4'-benzophenonetetracarboxylic dianhydride. The polyimide of the present invention is produced by reacting m moles of aromatic tetracarboxylic dianhydride (m is an integer of 1 to 10) represented by the formula () with (m+1) moles of the diamine represented by the formula (); It is obtained by further reacting 2 moles of maleic anhydride. For example, the method of JVCRIVELLO et al. [Journal of Polymer Science;
Science: Polymer Chemistry Edition)
Vol. 14, P. 159-182 (1976)], 1 mol of tetracarboxylic dianhydride and 2 mol of diamine were reacted in DMF at room temperature, and 2 mol of maleic anhydride was added. After preparing maleamic acid, nickel acetate and triethylamine were added and refluxed. Next, acetic anhydride is added to the system and the mixture is reacted under reflux, and then poured into a large amount of water to precipitate crystals, which are filtered and dried to obtain the desired polyimide. Further, the reaction is preferably carried out in the presence of a solvent and a catalyst. There are no particular restrictions on the reaction solvent, but preferably ketones such as acetone and 2-butanone, N,
Examples include aprotic polar solvents such as N'-dimethylformamide, N,N'-dimethylacetamide, -methylpyrrolidone, and dimethylsulfoxide. In addition to nickel acetate, the catalysts include cobalt acetate, alkali metal salts, alkaline earth metal salts, divalent nickel salts, divalent or trivalent iron salts, and copalt salts, as well as chlorides of these metals, Bromides, carbonates, acetates, etc. can be used. Examples of the tertiary amine include triethylamine, tri-n-propylamine, tri-n-butylamine, and the like. (Application) The polyimide represented by the formula () of the present invention undergoes radical polymerization by heating in the presence of peroxide, if necessary, to form a polymer. Further, when an amine or the like is used as a curing agent and heated, addition polymerization occurs in addition to the above-mentioned radical polymerization, giving a cured product with excellent heat resistance. Examples of peroxides that can be used in the polymerization of such polyimides include t-butyl hydroperoxide, kyumene hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, lauroyl peroxide, benzoyl peroxide, These include t-butylperoxypiparate, t-butylperoxybenzoate, and the like. Further, curing agents used in addition polymerization include (A) diaminodiphenylmethane, m-phenylenediamine, o- or p-phenylenediamine,
Aromatic amines such as diaminodiphenylsulfone; 2,6-diaminopyridine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dimethylethanolamine, ethylenediamine, 1,4-diaminobutane, 1,6-diaminohexane, 1, Amines such as 8-diaminooctane, 3,9-bis(3-aminopropyl)-2,4,8,10tetraoxaspiro[5,5]undecane. (B) Novolac phenols (for example, Gun-Ei Kagakusha trade name MP-617, 120M); alkylphenol novolacs, for example cresol novolac, butylphenol novolac, nonylphenol novolac; polyalkenylphenols, for example polyphenols; -P-vinylphenol,
Phenols such as poly-P-isoprobenylphenol. (C) 1,2 ethanedithiol, 1,3 propanedithiol, 1,2 propanedithiol, 1,6
Mercaptans such as hexanedithiol and 1,10-decanedithiol. (D) Malonitrile, α-carbamoylacetonitrile, phenylacetonitrile, α-carboxyacetonitrile, α-phenylsulfonylacetonyltrile, α-carbalkoxyacetonitrile, 1,4-bis(cyanomethyl)benzene, α-halocarbonylacetonitrile, α
- Active methylenes such as chloroacetonitrile, nitroalkane, acetylacetone, diethyl malonate, dialkyl acetoacetate, and the like. The curing agent is used in an amount of 5 to 100 parts by weight per 100 parts by weight of polyimide. In addition to a polymerization initiator and a curing agent, the following components can be added to the polyimide of the present invention, if necessary. (1) Powdered reinforcing agents and fillers, such as metal oxides such as aluminum oxide and magnesium oxide, metal carbonates such as calcium carbonate and magnesium carbonate, diatomaceous earth powder, basic magnesium silicate, calcined clay, and fine powder. Silica, fused silica, crystalline silica, carbon black, kaolin, finely powdered mica, quartz powder, metal hydroxides such as aluminum hydroxide, graphite, asbestos, molybdenum disulfide, antimony trioxide, etc. Furthermore, fibrous reinforcements and fillers, such as inorganic fibers such as glass fibers, rock wool, ceramic fibers asbestos, and carbon fibers, and synthetic fibers such as paper, pulp, wood flour, linters, and polyamide fibers. The amount of these powder or fibrous reinforcing agents and fillers used varies depending on the application, but up to 500 parts by weight can be used for 100 parts by weight of polyimide as a laminated material or molding material. (2) Coloring agents, pigments, flame retardants such as titanium dioxide, yellow lead carbon black, iron black, molybdenum red, navy blue, ultramarine blue, cadmium yellow, cadmium red, inorganic lints such as red phosphorus, organic phosphorus such as phenyl phosphate, etc. etc. (3) Furthermore, various synthetic resins can be blended for the purpose of improving the properties of the resin in the final coating film, adhesive layer, resin molded product, printed circuit board, etc. Examples include one or a combination of two or more of phenolic resins, alkyd resins, melamine resins, fluororesins, vinyl chloride resins, acrylic resins, silicone resins, polyester resins, and the like. The amount of these resins used is preferably within a range that does not impair the inherent properties of the polyimide of the present invention, that is, less than 50% by weight of the total resin amount. Examples of means for blending various additives and synthetic resins with this polyimide include heating and melt mixing, kneading using a roll, kneader, etc., mixing using an appropriate organic solvent, and dry mixing. (Examples) Hereinafter, the present invention will be described in detail with examples and application examples. Example 1 3, 3', 4,
80.6 g (0.25 mol) of 4'-benzophenone tetratetracarboxylic dianhydride and N-methylpyrrolidone
201.5g was charged and stirred to dissolve. Next, 3,9-bis(3-aminopropyl)-
A solution of 137.2 g (0.5 mol) of 2,4,8,10 tetraoxaspiro[5,5]undecane dissolved in 411.6 g of N-methylpyrrolidone was added to the temperature of the flask.
Drop slowly while keeping the temperature at 20 to 30℃, and after dropping,
Stirring was continued for 30 minutes at the same temperature. Next, 49.1 g (0.5 mol) of maleic anhydride was added to N
- A solution dissolved in 98.2 g of methylpyrrolidone was slowly added dropwise while keeping the temperature of the flask at 20 to 37°C.
After the dropwise addition was completed, stirring was continued for 30 minutes at the same temperature. Next, in this flask, add 0.5 g of nickel acetate,
12.5 ml of triethylamine and 102.1 g of acetic anhydride
was added, and the dehydration cyclization reaction was carried out by stirring for 3 hours while maintaining the temperature at 60°C. After the reaction is complete, the reaction product is poured into a large amount of water,
Crystals of the target polyimide were precipitated. After filtering the crystals, the crystals were washed with water and dried to obtain 152.8 g (yield: 61.5%) of pale yellow polyimide. The elemental analysis value of polyimide, which is the target material, is carbon 62.4
%, hydrogen 5.5%, and nitrogen 5.4% (theoretical values are carbon
61.6%, hydrogen 5.4%, nitrogen 5.6%). The softening point of this polyimide (capillary method) is 175~
It was 185℃. The infrared absorption spectrum of this polyimide is shown in FIG. 1, and the nuclear magnetic resonance spectrum is shown in FIG. Example 2 The same procedure as in Example 1 was carried out except that 54.6 g (0.25 mol) of benzenetetracarboxylic dianhydride was used instead of 3,3',4,4'-benzophenonetetracarboxylic dianhydride. In the same manner as in Example 1, 141.3 g of polyimide (yield 63.4%) was obtained. The softening point of this polyimide was 187-197°C. Application examples 1 and 2 The polyimides obtained in Examples 1 and 2 were melted at 150°C, thoroughly degassed, then poured into a mold, and heated at 250°C.
Curing was performed at ℃ for 10 hours to obtain a cured product. Table 1 shows the physical properties of the obtained cured product. Comparative Example 1 Bismaleimide obtained from 4,4'-methylene dianiline and maleic anhydride was thermally polymerized under the same conditions as in Application Examples 1 and 2 to obtain the cured products shown in Table 1. Application examples 3 and 4 As a curing agent for the polyimide obtained in Examples 1 and 2
39-bis(3-aminopropyl>-2,4,8,
10 Tetraoxaspiro[5,5]undecane (manufactured by Ajinomoto Co., Ltd.) was blended as shown in Table 2, and then dissolved in N,N-dimethylformamide so that the concentration of the resin portion was 20% by weight. This solution was cast and pre-cured at 150°C for 1.5 hours and post-cured at 230°C for 3 hours to obtain a highly flexible and strong film. Table 2 shows the physical properties of the obtained film. Comparative Example 2 A film was prepared in the same manner as in Application Examples 3 and 4, except that 2.0 g of hexamethylene diamine was used as a curing agent in an equivalent amount to 9.52 g of bismaleimide obtained by reacting hexamethylene diamine and maleic anhydride. . Table 2 shows the physical properties of the obtained film. Comparative Example 3 50 parts by weight of Epomate BOO ₂ (trade name) manufactured by Yuka Ciel Epoxy Co., Ltd. as a curing agent was blended with 100 parts by weight of the diclidyl ether of bisphenol A Epicoat E828 manufactured by Yuka Ciel Epoxy Co., Ltd. Then, it was dissolved in methyl ethyl ketone so that the concentration of the resin part was 20% by weight. This solution was cast and cured at 80° C. for 3 hours to obtain a film having the physical properties shown in Table 2.

【table】

【table】

[Table] Test method *1 DSC, temperature raised in _N2 gas at 10℃/〓 condition.
*2 Mandrel test method (JIS-K-5400)

[Brief explanation of the drawing]

1 and 2 are an infrared absorption spectrum and a nuclear magnetic resonance spectrum of the polyimide obtained in Example 1, respectively.

Claims (1)

[Scope of Claims] 1 A novel polyimide represented by the following general formula: [In the formula, Z represents [Formula] or [Formula], n is an integer of 1 to 6, and m is an integer of 1 to 10. Indicates an integer. ]