阅读说明：本技术 芳香族四羧酸化合物 (Aromatic tetracarboxylic acid compound ) 是由 藤冈利恵 西原匡彦 于 2019-10-07 设计创作，主要内容包括：本发明的课题在于提供一种新型化合物,其可抑制固化反应时固化剂的挥发,提供耐热性等各项特性优异的固化剂。作为解决方法,提供一种芳香族四羧酸化合物,其特征在于,由下述式(I)所示,[化学式1]式中,R各自独立地表示碳原子数1～4的烷基或碳原子数1～4的烷氧基,n各自独立地表示0或1～4的整数。(The present invention addresses the problem of providing a novel compound that can inhibit volatilization of a curing agent during a curing reaction and that provides a curing agent having excellent properties such as heat resistance. As a means for solving the problem, an aromatic tetracarboxylic acid compound represented by the following formula (I) [ chemical formula 1]])

1. An aromatic tetracarboxylic acid compound represented by the following formula (I),

[ chemical formula 1]

Wherein R independently represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and n independently represents 0 or an integer of 1 to 4.

Technical Field

The present invention relates to a novel aromatic tetracarboxylic acid compound.

Background

Carboxylic acid compounds are compounds widely used in the fields of organic chemistry and polymer chemistry, and are a group of compounds useful in a variety of fields for industrial use, such as fine chemistry, materials for medical and agricultural chemicals, resins and plastics, electronic information materials, and optical materials. Among them, polycarboxylic acids and anhydrides thereof are useful as monomers for polymer materials, for example, as raw materials for polyimides and the like, as polyester resin modifiers, and as epoxy resin curing agents, because they are excellent in various properties such as heat resistance, good mechanical properties, electrical properties, and chemical resistance, and also have good formation and reactivity of condensates.

Saturated hydrocarbon acid anhydrides such as methylhexahydrophthalic anhydride and methyltetrahydrophthalic anhydride are widely used as curing agents for epoxy resins because cured products thereof are excellent in light resistance, but these curing agents are high in vapor pressure and therefore partially volatilize during curing reaction, and if thermosetting is performed in an open system, the curing agents volatilize into the atmosphere, which not only adversely affects workers, but also causes problems such as line contamination.

Patent document

Patent document 1: japanese patent laid-open publication No. 2004-352670

Patent document 2: japanese patent laid-open publication No. 2011-

Patent document 3: japanese Kokai publication No. 2014-503669

Disclosure of Invention

The present invention addresses the problem of providing a novel compound which, when used as a curing agent for epoxy resins, can inhibit volatilization of the curing agent during the curing reaction and can provide a curing agent having excellent properties such as heat resistance.

The present inventors have conducted extensive studies to solve the above problems, and as a result, have found that when an aromatic tetracarboxylic acid compound having a biphenyl skeleton is used as an epoxy resin curing agent, volatilization during curing reaction is suppressed, and a cured product having excellent heat resistance is provided, thereby completing the present invention.

The present invention is as follows.

1. An aromatic tetracarboxylic acid compound represented by the following formula (I),

[ chemical formula 1]

Wherein R independently represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and n independently represents 0 or an integer of 1 to 4.

The present invention provides a novel aromatic tetracarboxylic acid compound having a biphenyl skeleton. When the novel aromatic tetracarboxylic acid compound is used as an epoxy resin curing agent, volatilization during curing reaction can be reduced, and therefore, contamination of a production line, deterioration of a working environment, and the like can be suppressed. Further, the resin obtained by using the novel aromatic tetracarboxylic acid compound of the present invention as an epoxy resin curing agent is excellent in heat resistance, flame retardancy and the like, and therefore, can be suitably used for the production of resins such as electric and electronic molded parts, automobile parts, laminates, paints, resist inks and the like.

Detailed Description

The aromatic tetracarboxylic acid compound of the present invention is represented by the following formula (I).

[ chemical formula 2]

(wherein R independently represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, and n independently represents 0 or an integer of 1 to 4.)

In the above formula (I), the chemical structure of "4- ({4- [4- (3, 4-dicarboxyphenylcarbonyloxy) -2,3, 5-trimethylphenyl ] -2,3, 6-trimethylphenyl ] oxycarbonyl } benzene-1, 2-dicarboxylic acid" (hereinafter referred to as "chemical A") which is a suitable compound is shown below.

[ chemical formula 3]

The method for producing the aromatic tetracarboxylic acid compound represented by the formula (I) of the present invention is not particularly limited in terms of raw materials, reaction conditions, and the like, and can be easily obtained by hydrolyzing an aromatic tetracarboxylic dianhydride, for example, as shown in the following reaction formula.

[ chemical formula 4]

(wherein R, n has the same meaning as in the formula (I))

As the reaction conditions for hydrolyzing the aromatic tetracarboxylic dianhydride, a method of hydrolyzing an alkyl ester to produce a carboxylic acid can be generally applied. Examples of the acid used include inorganic acids represented by phosphoric acid, hydrochloric acid, sulfuric acid, and the like, and sulfonic acids represented by methanesulfonic acid, p-toluenesulfonic acid, and the like. Among them, the method using phosphoric acid is simple. The amount of phosphoric acid used is preferably about 0.1 to 5% by weight, more preferably 1 to 3% by weight, based on the aromatic tetracarboxylic dianhydride.

The reaction solvent may be a water-miscible solvent such as methanol, ethanol, 1-propanol, 2-propanol, tetrahydrofuran, or N-methylpyrrolidone, and tetrahydrofuran, particularly tetrahydrofuran containing 2, 6-di-t-butyl-4-methylphenol (BHT) as a stabilizer, is most suitable. The amounts of tetrahydrofuran and water used are preferably 3 to 5 times by weight based on the aromatic tetracarboxylic dianhydride, respectively.

The hydrolysis reaction can be carried out by adding water and a catalytic amount of phosphoric acid to a solution of aromatic tetracarboxylic dianhydride in tetrahydrofuran, setting the reaction temperature to a range of 30 to 65 ℃, preferably 40 to 60 ℃, and heating and stirring the mixture to obtain the target product.

The reaction time is preferably 1 to 40 hours, more preferably 2 to 30 hours, in practice, although it depends on the reaction temperature.

The reaction-completed mixture containing the aromatic tetracarboxylic acid compound of the present invention thus obtained may be subjected to filtration of the reaction solution as it is or after cooling, and the obtained crystals may be dried to obtain the desired product, if crystals or solids of the desired product precipitate or precipitate after the reaction is completed. Further, if crystals or solids of the objective substance do not precipitate or precipitate at the end of the reaction, the objective substance can be extracted from the reaction-completed mixture by a known method. For example, the target product can be precipitated or precipitated by dropping the reaction-completed mixture into a large amount of the poor solvent or by adding the poor solvent to the reaction-completed mixture. The obtained target product can be recrystallized or washed with water according to a known method, if necessary, to obtain a high-purity product.

Examples

The present invention will be described more specifically with reference to examples.

In addition, the yields in the following examples were measured by Gel Permeation Chromatography (GPC).

< analytical method >

1. Gel permeation chromatography assay

The device comprises the following steps: HLC-8320GPC, manufactured by Tosoh corporation

Flow rate: 1.0ml/min, mobile phase: tetrahydrofuran, injection amount: 100 μ l

A chromatographic column: TSKgel guardcolumn HXL-L1 root, TSKgel G2000HXL 2 root, TSKgel G3000HXL 1 root, TSKgel G4000HXL 1 root

A detector: RI (Ri)

Temperature of the column: 40 deg.C

Fluidized bed solvent: tetrahydrofuran containing BHT

< example 1 > (Synthesis of aromatic tetracarboxylic Compound "Compound A")

To a 500mL four-necked flask equipped with a stirrer, a thermometer and a cooling tube, 50.7g of 4,4 '-bis (1, 3-dioxo-1, 3-dihydroisobenzofuran-5-ylcarbonyloxy) -2,2',3,3',5,5' -hexamethylbiphenyl, 152.1g of tetrahydrofuran containing BHT, 152.1g of water and 0.507g of 85% phosphoric acid were added, and the mixture was heated to 40 ℃ under nitrogen atmosphere with stirring, and then reacted for 25 hours while maintaining the temperature at 40 ℃. Further, the temperature was raised to 50 ℃ to react for 4 hours. 85g of water was then dropped. During the dropping, a solid precipitated at room temperature. The precipitated solid was filtered and dried to obtain 48.9g (yield 91.4 mol%) of a white to beige solid having a purity of 96.8% (analysis by GPC measurement data).

By¹H-NMR、¹³As a result of C-NMR analysis, it was confirmed that the obtained solid was "Compound A" having the above chemical structure.

¹H-NMR (300MHz) determination in ppm (solvent: deuterated DMSO): 1.97(s,6H: a), 2.11(s,6H: b), 2.14(s,6H: c), 6.97(s,2H, d), 7.89-7.91(d,2H, e), 8.40-8.43(dd,2H, f), 8.48(s,2H: g), 13.60(s,4H: H).

[ chemical formula 5]

¹³C-NMR (300MHz) measurement ppm (solvent: deuterated methanol): 11.96(a), 14.99(b), 15.59(c), 126.80-139.79, 147.10(p), 163.28(q), 168.10(r), 169.26 (z).

[ chemical formula 6]