JPH11116566A - Cyclic carbonate resin composition and its cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition useful as a raw material for molding materials, composite materials, casting materials, sealing materials, coatings, adhesives and the like by including a specific oligonorbornene, an epoxy resin and a polymerization initiator. SOLUTION: This composition comprises (A) an oligonorbornene of the formula [(n) is 1-10; (x), (y) are each 0-3] having n cyclic carbonate structures on side chains, (B) an epoxy resin (preferably a bisphenol-based epoxy resin or the like) and (C) an amine-based anionic ring-opening polymerization initiator preferably 1,8-diazabicyclo[5,4.0]undec-7-ene or the like). The components A and B are preferably used in a ratio of 5/95 to 60/40. The component C is preferably used in an amount of 0.1-5 wt.% based on the component A. The polymerization reaction is preferably carried out at 50-180 deg.C. The composition may, if necessary, be compounded with additives such as a filler, a dye and a pigment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an oligonorbornene resin having a cyclic carbonate structure in a side chain and a cured product thereof. The oligonorbornene and polymer having a cyclic carbonate structure in the side chain according to the present invention show volume expansion during polymerization, and are required to have dimensional accuracy, adhesion, heat resistance, etc., molding materials, composite materials, casting materials, sealing. It is useful as a raw material for materials, paints and adhesives.

[0002]

2. Description of the Related Art It is well known that vinyl monomers such as styrene and methyl methacrylate generally undergo large shrinkage during polymerization. Further, when a thermosetting resin such as an epoxy resin, a phenol resin, or an unsaturated polyester resin is cured, volume contraction occurs. These shrinkages have a large effect on the physical properties of the cured product, and cause various problems such as the occurrence of voids, cracks, poor appearance, etc., or a decrease in adhesive strength.Therefore, in the fields of casting materials, sealing materials, adhesive materials, etc. It is a big problem. If a material that does not exhibit shrinkage during polymerization can be obtained, improvement in dimensional accuracy, precise molding by reducing warpage, distortion, and peeling, and improvement in material strength and adhesive strength by reducing internal stress can be expected.

[0003] In order to solve the above problems, for example, inorganic fillers such as silica, calcium carbonate, and alumina are added to reduce curing shrinkage. However, the addition of such an inorganic filler is effective in improving the strength, but increases the viscosity of the resin composition, thereby deteriorating workability. Further, there is a problem that the adhesive property of the resin composition is lowered, causing peeling, cracking, and the like at the adhesive interface. Attempts have also been made to add a resin compatible with the epoxy resin to the epoxy resin, thereby preventing volume shrinkage (Japanese Patent Publication No. 58-57423). Is often not preferred.

On the other hand, it has been reported that a cyclic carbonate compound increases its volume during ring-opening polymerization, and its application to the above-mentioned various applications has attracted attention. For example, Lewis acid cationic polymerization initiators such as methyl trifluoromethanesulfonate and boron trifluoride ether complex, and alkoxides such as sodium methoxide, n-butyllithium, sec.
It is known that ring-opening polymerization of an alkyllithium such as -butyllithium as an anionic polymerization initiator causes volume expansion (Macromolecules, Vo)
l.24, No.15, 4229-4235 (1991), Proceedings of the 65th Annual Meeting of the Chemical Society of Japan, 271 (1993), Proceedings of the 43rd Annual Meeting of the Society of Polymer Science, 294 (1994) ).

The ring-opening polymerization of a cyclic carbonate compound using a Lewis acid-based cationic polymerization initiator is difficult to handle during polymerization because a Lewis acid which is a strong acid such as methyl trifluoromethanesulfonate or a boron trifluoride etherate complex is used. In addition, the workability was poor due to the large influence of moisture. Furthermore, the presence of an acid component causes problems such as corrosion of the metal, and cannot be used for electronic materials. In addition, in the ring-opening polymerization method of a cyclic carbonate compound by anionic polymerization using an alkoxide-based initiator such as sodium methoxide or an alkyllithium-based initiator such as sec-butyllithium, the activity of the initiator is reduced by moisture. It has a remarkably large effect on ring-opening polymerization, and cannot be used as an electronic material because of the presence of ionic impurities such as sodium ions and lithium ions, and industrially useful applications have been found. Did not.

[0006] Furthermore, copolymerization of cyclic carbonate and epoxide has been attempted, but the reaction of cationic polymerization (the 42nd Polymer Symposium, 2139 (1993),
All reactions using coordination anion polymerization catalysts are susceptible to moisture and are not used industrially (Polyme
r, Vol.33, No.9,1941-1948 (1992))

The norbornene cyclic carbonate represented by the chemical formula (2), which is one of the cyclic carbonates, has a larger volume expansion at the time of polymerization than other cyclic carbonates. Norbornene cyclic carbonate hardly causes a side reaction such as an attack reaction of the terminal growing species on the polymer chain, so that a high molecular weight polymer can be easily obtained. Furthermore, it shows relatively high heat resistance to other cyclic carbonates than the skeleton of norbornene, and is attracting attention as an interesting compound.

[0008]

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[0009] However, the norbornene cyclic carbonate is, as shown by the chemical formula (3), 150-300.
Heating at ℃ causes retro Diels-Alder reaction to decompose into cyclic carbonate having cyclopentadiene and exomethylene. This decomposition also occurs in a polymer as shown by the chemical formula (4), and there is a problem with a material used at a high temperature of 150 ° C. or higher, and it has not been applied to a material requiring heat resistance. .

[0010]

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[0011]

Embedded image (The repeating unit 1 is an integer from 1 to 100)

[0012]

Accordingly, the present inventors have developed compounds and polymers which have improved heat resistance and expand in volume upon curing, and as a result, have newly synthesized cyclic carbonates shown below. The inventors have found that ring-opening polymerization is carried out by an anionic polymerization initiator and, after curing, the heat resistance is improved as compared with the norbornene cyclic carbonate polymer, thereby completing the present invention.

[0013]

That is, the present invention uses, as components, an oligonorbornene having n cyclic carbonate structures in a side chain represented by the chemical formula (1), an epoxy resin, and an amine-based anionic ring-opening polymerization initiator. It is a cyclic carbonate resin composition characterized by that

[0014]

Embedded image (Repeating unit n is an integer from 1 to 10) (where x and y are integers from 0 to 3)

The cyclic carbonate of oligonorbornene having a cyclic carbonate structure in the side chain represented by the chemical formula (1) is copolymerized with an epoxy resin, and the polymerization ratio is 1/99.
And a cured product obtained by curing the resin composition.

The method for producing the cyclic carbonate compound used in the present invention can be referred to the one obtained by a known method (39th Annual Meeting of the Society of Polymer Science, 284 (1990)). .

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin used in the above reaction is not particularly limited as long as it is an epoxy resin, but an aromatic epoxy resin such as a bisphenol epoxy resin, a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, etc. Resin, alicyclic epoxy resin,
Heterocyclic epoxy resins and the like are mentioned as preferred, and they may be used alone or as a mixture of two or more compounds.

The amine-based ring-opening polymerization initiator used in the present invention includes diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, benzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,4, 6-tris (diaminomethyl) phenol, triethylamine, diethylamine, ethylamine, aniline, tetramethylguanidine, alkyl tert monoamine and the like.

Particularly, when the amine-based ring-opening polymerization initiator is a cyclic amine compound, examples of the initiator include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole,
-Phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 2,4-diamino-6- [2-methylimidazolyl-
(1)]-Ethyl S-triazine, piperidine, N, N'-
Dimethylpiperazine, pyridine, picoline and the like.

Among the cyclic amine compounds, in particular, 1,8-diazabicyclo [5,4,0] undec-7-ene (DBU),
Triethylenediamine and 4-dimethylaminopyridine react remarkably fast with oligonorbornene having a cyclic carbonate structure in the side chain represented by the chemical formula (1), and have a high molecular weight and a high yield. The anionic initiator is used in an amount of 0.01 to 15% by weight, preferably 0.1 to 5% by weight, based on the oligonorbornene having a cyclic carbonate structure in the side chain represented by the chemical formula (1). Used. 0.
If the amount is less than 01% by weight, the polymerization proceeds, but a long time is required, which is not preferable. On the other hand, if the concentration exceeds 10% by weight, a low molecular weight compound is easily generated, which is not preferable.

The proportion of the components of the oligonorbornene having a cyclic carbonate structure in the side chain and the epoxy resin is preferably such that the weight ratio of the oligonorbornene having the cyclic carbonate structure in the side chain to the epoxy resin is 1/99 to 80/20. Is 5/95 to 60/40. If it is less than 1/99,
Shrinkage after curing is suppressed more than the reaction of the epoxy resin alone, but the adhesion is low and the effect of low shrinkage is low. On the other hand, when it exceeds 80/20, the volume expansion becomes large, but it is not preferable because a cured product cannot be produced. The conditions for these polymerization reactions vary depending on the type and amount of the curing accelerator, but are usually in the range of room temperature to 200 ° C, preferably 50 to 180 ° C.

The compound of the present invention may optionally contain additives such as fillers, dyes and pigments. As the filler, organic materials such as wood powder, pulp powder, pulverized woven materials, pulverized thermosetting resin laminates and pulverized products,
Silica, glass, talc, alumina, calcium carbonate,
Inorganic powders such as carbon, glass fibers, carbon fibers, and inorganic fibers such as mica can be selected.

[0023]

The present invention will be specifically described below based on examples and comparative examples. In addition, the physical property value was measured by the following method.

The ¹ H-NMR spectrum was measured using a model JSX-400 manufactured by JEOL Ltd., and the infrared absorption spectrum was measured using a model FT / IR-3 manufactured by JASCO Corporation. The number average molecular weight was measured using a GPC-8000 system measuring device manufactured by Tosoh Corporation, and calculated in terms of polystyrene. The density was measured in an aqueous solution of potassium bromide or calcium bromide at 25 ° C. using a density gradient tube method specific gravity measurement device A manufactured by Shibayama Scientific Instruments Co., Ltd.

While the specific gravity of the obtained resin composition at 25 ° C. was measured, this resin composition was polymerized, and the volume expansion coefficient was determined from the difference in specific gravity before and after the polymerization. The 10% weight loss temperature was measured by weight loss when heated from room temperature to 800 ° C. at a rate of 10 ° C./min by a thermogravimetric method (TG). Norbornene cyclic carbonate

[0026]

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In the production method, an aqueous KOH solution was added dropwise to a methanol solution of an aqueous solution of 5-norbornene-2-carboxaldehyde and formaldehyde, and the mixture was refluxed for 5 hours. After removing the solvent, the precipitated solid was washed with water and recrystallized, and 5-norbornene-2,2-dimethanol was added to 69
% Yield. Next, triethylamine was added dropwise to the toluene solvent of the diol and ethyl chloroformate under water cooling. After washing the reaction solution with water, the solvent was removed, and the precipitated solid was recrystallized from toluene to obtain norbornene cyclic carbonate in a yield of 49%.

The method for producing an oligonorbornene having a cyclic carbonate structure in the side chain is as follows: using norbornene cyclic carbonate (153.0 g, 1.252 mol) and di-t-butyl peroxide (DTBP, 3,8 g) as an initiator, Stirring was carried out in DMF (2.0 M) at 120 ° C. for 20 hours. The polymerization mixture is reprecipitated in n-hexane / ethanol (volume ratio: 1.5: 1.0) to have a cyclic carbonate structure in a side chain having a number average molecular weight of 620 and a molecular weight distribution of 1.2 in a yield of 60%. Oligonorbornene (50
g) was obtained. When the ¹ H-NMR spectrum of the product was observed, 4H, δ was found at δ = 4.06 to 4.24 ppm.
A peak of 11H was observed at 0.88 to 2.35 ppm. Observation of the IR spectrum of the product showed that
957, 1750, 1182, 1125, 1107 cm
^A peak was observed at ^-1 . From this result, it was identified that the product was oligonorbornene having a cyclic carbonate structure in the side chain.

Example 1 Oligonorbornene having a cyclic carbonate structure in the side chain and glycidyl-1-naphthyl ether

[0030]

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The copolymerization reaction was conducted at a reaction temperature of 120 ° C. for 1 hour using DBU (4 mol%) as an initiator. The obtained copolymer has a yield of 7
At 2%, the unit ratio between carbonate and epoxide is N
It was 47:53 as measured by MR. The 10% weight loss temperature was 267 ° C.

[Comparative Example 1] The unit ratio of norbornene cyclic carbonate (2) and glycidyl-1-naphthyl ether was set to 50:50, and the copolymerization reaction was conducted using DBU.
(4 mol%) as an initiator at a reaction temperature of 120 ° C, 1
Time went. The obtained copolymer had a yield of 73%, and the unit ratio of carbonate to epoxide was 54:46 as measured by NMR. The 10% weight loss temperature is 22
5 ° C.

Example 2 Oligonorbornene having a cyclic carbonate structure in the side chain,

[0034]

Embedded image (N is an integer from 1 to 5)

YX-4000H and DBU were blended at the composition ratio (parts by weight) shown in Table 1 and mixed to prepare a resin composition. While measuring the specific gravity of the obtained resin composition at 25 ° C., the resin composition was cured by heating at 100 ° C. for 3 hours, 120 ° C. for 2 hours, 150 ° C. for 6 hours, and 180 ° C. for 2 hours. Was used to determine the volume expansion coefficient. Further, the coefficient of thermal expansion and the glass transition temperature were measured by TMA (thermomechanical test). Tensile shear strength was measured by coating the above-mentioned resin mixture on the metal plating surface of the laminated sheet, and attaching chips on it.
Heating was performed at 20 ° C. for 2 hours, 150 ° C. for 6 hours, and 180 ° C. for 2 hours, and the measurement was performed using a CIP gauge manufactured by AIKOH Engineering Co., Ltd. Table 1 shows the results.

(Examples 3 to 9, Comparative Examples 2 to 7) After mixing the materials at the ratios shown in Table 1, various physical properties were measured in the same manner as in Example 2. Tables 1 and 2 show the measurement results.

[0037]

[Table 1]

* 1) Annular carbonate
(180 [g / eq]) * 2) Yuphenyl Shell Epoxy Co., Ltd., biphenyl type epoxy resin (epoxy equivalent: 195 [g / eq]) * 3) Sumitomo Chemical Co., Ltd., ortho-cresol novolak type Epoxy resin (epoxy equivalent: 200 [g / eq]) * 4) Naphthalene type epoxy resin (Epoxy equivalent: 152 [g / eq]) manufactured by Dainippon Ink and Chemicals, Inc. * 5) Yuka Shell Epoxy Co., Ltd. ), Bisphenol A
Type epoxy resin (epoxy equivalent: 180 [g / eq]) * 6) Daicel Chemical Industries, Ltd., alicyclic epoxy resin (epoxy equivalent: 131 [g / eq]) * 7) Minus indicates shrinkage .

[0039]

[Table 2]

[0040]

By reacting an oligonorbornene having a cyclic carbonate structure in a side chain with an epoxy resin using an amine-based anionic ring-opening polymerization initiator, a polymer having a small curing shrinkage can be obtained. Shows excellent properties.
Therefore, it is useful for applications of industrial materials such as casting materials, sealing materials, and adhesive materials.

Claims (3)

[Claims] 1. A cyclic carbonate resin composition comprising, as components, an oligonorbornene having n cyclic carbonate structures in a side chain represented by a chemical formula (1), an epoxy resin, and an amine-based anion ring-opening polymerization initiator. . Embedded image (Repeating unit n is an integer from 1 to 10) (where x and y are integers from 0 to 3) 2. A cyclic carbonate of oligonorbornene having a cyclic carbonate structure in a side chain represented by the chemical formula (1) is copolymerized with an epoxy resin, and the polymerization ratio is 1/9.
A resin composition ranging from 9 to 80/20. 3. A cured product obtained by curing the resin composition according to claim 2.