JPH0517902B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a bisacrylate compound having thermal anisotropy. The bisacrylate compound of the present invention can easily undergo a curing reaction, and is useful as a structural material with excellent heat resistance, a matrix resin for carbon fiber composite materials, an adhesive, a sealant, and a resin for powder coatings. .

[Conventional technology]

In certain compounds, the melt exhibits anisotropy (the molecules align their long axes in one direction in the molten state) at a certain temperature, and a three-dimensional crosslinking reaction is performed in this anisotropic state to form high crystals. It is known to obtain a cured product of

For example, the general formula [In the formula, X is H or Cl. ] It has been reported that the alrylate compound having an azomethine group shown in the following shows thermal anisotropy, and that the three-dimensional crosslinked product obtained in this state also shows anisotropy. [Macromolecule, No. 9]
Vol. 123, 1976 and Bull.Soc.Chem.Fr., 1973.
, pp. 579 and 605].

On the other hand, epoxy compounds are well known as compounds that three-dimensionally crosslink. An epoxy compound having a specific skeleton, for example a polyepoxy compound having a cyanostilbene group, exhibits thermal anisotropy,
A uniformly anisotropic cured product can be obtained.

[Problem that the invention seeks to solve]

However, this acrylate compound has a high melting point of 180°C and exhibits anisotropy at the same temperature, but since the acrylate compound polymerizes at the same time as it melts at this temperature, additives such as fillers and pigments are mixed in. It is difficult to obtain a cured product with a uniform composition.

Further, the heat resistance of the cured product of the polyepoxy compound is still not sufficient. (See Comparative Example) [Specific Means to Solve the Problems] The present inventors have developed a compound that has a sufficiently long pot life at temperatures at which it exhibits anisotropy, has excellent workability during molding, and has excellent heat resistance. After synthesizing and studying various compounds for the purpose of obtaining a compound that provides a polymer with a three-dimensional structure, it was found that a bisacrylate compound represented by the following formula [] exhibits thermal anisotropy and satisfactorily achieves the above purpose. This discovery led to the completion of the present invention.

The bisacrylate compound represented by the above formula [] is a formula synthesized by a condensation reaction of the compounds represented by the following formulas (a) and (b) in the presence of an alkali catalyst.
It is synthesized by acrylating a compound represented by the formula [] obtained by an ether cleavage reaction of the compound represented by (c).

The above condensation reaction, ether cleavage reaction and arylation reaction are known.

For example, (1) Condensation reaction: Organic Syntheses, Vol. 715, or Journal of American Chemistry Soc., Vol. 64, No. 885.
Page, 1942, (2) Ether cleavage reaction: New Experimental Chemistry Course, Volume 14, Page 538, (3) Acrylation reaction: New Experimental Chemistry Course, Volume 14, Page 1000. There is.

Specifically, for example, methanol and ethanol or tetrahydrofuran, 1,4-dioxane and N,N-dimethylformamide and methanol or ethanol are used at a ratio of 1 mole of p-anisaldehyde to 1 mole of p-methoxyphenylacetonitrile. The compound obtained by reacting at room temperature in the presence of an alkali catalyst in a mixed solvent for 3 to 4 hours is boiled for 10 hours in a mixed solvent of acetic acid and hydrobromic acid to obtain the precursor represented by the formula []. obtain.

A compound of formula [] can be obtained by acrylating 1 mole of this precursor with 2 moles of acryl chloride in the presence of an alkali catalyst.

As the alkali catalyst for the condensation reaction, sodium hydroxide, potassium hydroxide, sodium methylate, sodium ethylate, potassium butylate, etc. are used.

As an alkaline catalyst for acrylation reaction,
Alkali catalysts and tertiary amine compounds used in the above condensation reaction, such as triethylamine, tri-n-butylamine, N,N-dimethylaniline, and pyridine, can be used.

The bisacrylate compound represented by the formula [] of the present invention has a sufficient pot life at the temperature indicated by thermal anisotropy, is easily cured by heating for 3 to 5 hours, and exhibits excellent heat resistance. You can get things.

The bisacrylate compound of the present invention may optionally contain a radical initiator, a plasticizer, an organic solvent, a reactive diluent, an extender, a filler, a reinforcing agent, a pigment, a flame retardant, a thickener, and a flexibilizer. Various additives such as a sex imparting agent can be blended.

〔Example〕

A more specific explanation will be given below with reference to Examples, but these Examples are merely illustrative and the present invention is not limited by the Examples.

Example A solution of 10 g of potassium hydroxide completely dissolved in 150 ml of ethanol was placed in a 500 ml four-necked flask equipped with a thermometer, a condenser, a dropping device, and a stirring device, and then 13.9 g of p-anisaldehyde was added. Stirred. While stirring, 15.0 g of p-methoxyphenylacetonitrile was added dropwise into the flask from a dropping device over about 0.5 hours, and the mixture was allowed to react at room temperature for 3.0 hours.

After the reaction, cool on ice and separate the precipitated crystals.
Wash with ethanol, dry, pale green Compound 21.1
g (yield 78%) was obtained.

Next, 750 ml of acetic acid containing 20 g of the above light green compound was placed in a four-necked flask (1) equipped with the same device as above, and 150 ml of hydrobromic acid was added dropwise from the dropping device, followed by a reaction in a boiling state for 10 hours. Ta.

After the reaction was completed, the reaction solution was poured into 2.5 g of ion-exchanged water, and the precipitated crystals were separated, washed with water, and dried to give 10.9 g of the compound represented by the following formula (yield:
61%). The melting point of this crystal was 243°C.

31.4g of the above precursor and 11.0g of sodium hydroxide
was added to 300 ml of an aqueous solution containing dissolved. While vigorously stirring this aqueous solution, arlylyl chloride 25.0
A solution of 200 ml of dichloromethane was added dropwise over 2 hours. The reaction temperature at this time was ice-cooled so as not to fall below 4°C. After the dropwise addition was completed, the mixture was stirred for 10 minutes, 200 ml of dichloromethane was added, and the reaction mixture was placed in a separatory funnel and allowed to stand to separate into two liquid phases. After washing the dichloromethane solution with water, the precipitated crystals were washed with methanol and dried to obtain 29.5 g (yield: 61.0%) of the bisacrylate compound of formula []. NMR
It was confirmed from the spectrum (Fig. 1) that it was acrylated. This compound exhibits liquid crystallinity at 165°C when heated on a hot plate, and exhibits liquid crystallinity at 180°C.
With this, the liquid became an isotropic liquid.

Note that hexamethylene disiloxane (HMDSO) was used as a reference material for the NMR spectrum.

Put 6.0g of this compound into a mold and place it in an oven for 170 minutes.
A curing reaction was carried out by heating at ℃ for 4 hours. Figure 2 shows the thermal characteristics of this cured product when it was heated at 10°C/min in an air atmosphere. From the figure, this cured product is
No weight loss was observed up to around 350°C.

Comparative Example: 100 parts by weight of a polyepoxy compound of the following formula obtained by epoxidizing the precursor represented by the formula []
Figure 2 shows the thermal properties of the cured product obtained by adding 3 parts by weight of -ethyl-4-methylimidazole, melting the mixture at 120°C, and curing it at 70°C for 4 hours.

[Brief explanation of the drawing]

Figure 1 shows the bisacrylate obtained in the example.
FIG. 3 is a diagram showing an NMR spectrum (solvent DCCl ₃ ).
FIG. 2 is a diagram showing the thermal characteristics of the cured products obtained in Example 1 and Comparative Example 2 when the temperature axis and initial weight are the same.

Claims (1)

[Claims] Linear formula A bisacrylate compound represented by