JP3258126B2 - Thermosetting resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel thermosetting resin composition having excellent heat resistance.

[0002]

2. Description of the Related Art In general, a high molecular weight aromatic polycarbodiimide resin is known as a resin having high heat resistance.
However, practical molding is difficult due to the drawbacks of being insoluble in various solvents and having poor thermal fluidity. In addition, polycarbodiimide is cured by causing self-crosslinking between carbodiimide bonds by heating, but the curing speed is slow, which makes practical molding as a cured resin more difficult. Thus, LMAlberino et al. (J. Appl. Polym. Sci., Vol. 21, 1999 [1977]) have proposed to solve the above-mentioned problems by converting an aromatic diisocyanate and an organic monoisocyanate as a molecular weight modifier into a carbodiimide. By reacting in the presence of the formed catalyst, a polycarbodiimide which is fluid under heat and pressure is obtained. Although the flowability of the polycarbodiimide obtained by this method can be improved by adjusting the molecular weight, it requires a considerably long time for curing and is not practical.

On the other hand, Japanese Patent Application Laid-Open Nos. 61-235414 and
To reduce the curing time, 1-245415 discloses polycarbodiimide of which molecular weight is controlled, phenol derivatives such as 4,4'-isopropylidenediphenol (bisphenol-A), aminotriazine, and 4,4'-diaminodiphenylmethane. A method has been proposed in which a crosslinking agent having an active hydrogen group is mixed and the composition is thermally cured to obtain a thermosetting resin. However, since the active hydrogen group is used, the heat resistance is reduced, and the excellent heat resistance inherent in the carbodiimide bond cannot be utilized, and the fluidity under heating also decreases. In addition, since the active hydrogen compound is difficult to dissolve in general-purpose organic solvents such as benzene and toluene, the thermosetting resin composition cannot be used as a varnish. .

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned drawbacks as a thermosetting resin having a carbodiimide bond, that is, it has excellent heat resistance, good fluidity at the time of melting, Another object of the present invention is to provide a composition for obtaining a thermosetting resin having a short curing time and usable as a varnish.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, the composition of a compound having a carbodiimide bond and a compound having a phenol derivative having an allyl group has been described. The present inventors have found that the above object can be met, and arrived at the present invention.

That is, the present invention comprises (A) a polycarbodiimide compound having two or more carbodiimide bonds in a molecule, and (B) a phenol derivative having at least two or more allyl groups in a molecule as essential components. It is intended to provide a thermosetting resin composition.

Preferably, the polycarbodiimide compound is
It contains 5-95 equivalents of a group having a structural unit represented by the following formula (I) and 95-5 equivalents of a group having a structural unit represented by the following formula (II), and the terminal of the polymer molecule is aromatic. A carbodiimide copolymer which is sealed with a group and has a weight average molecular weight of 10,000 or less.

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Embedded image The aromatic group at the molecular end of the polycarbodiimide compound is preferably a phenyl group, an ortho-tolyl group, a meta-tolyl group, a para-tolyl group, a dimethylphenyl group, a chlorophenyl group, a trifluoromethylphenyl group, a naphthyl group,
At least one member selected from the group consisting of an isopropylphenyl group and a diisopropylphenyl group.

[0008] More preferably, the polycarbodiimide compound is a compound represented by the following formula (III) and having a weight average molecular weight of 20,000 or less.

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The phenol derivative having an allyl group is preferably represented by the following formula (IV).

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Hereinafter, the configuration will be described in detail. The organic compound containing two or more carbodiimide bonds in the molecule used in the present invention can be used as long as it has a structure of the following formula (V) in the molecular chain, but it is particularly preferable to use polycarbodiimide. .

Embedded image Polycarbodiimide is a polymer compound having a large number of carbodiimide bonds in a molecular chain, and the compound itself is known, and is produced in the presence of a catalyst that promotes carbodiimidization of isocyanate from organic polyisocyanate, and is prepared using varnish or , Can be obtained as a powder.

When polycarbodiimide is used as a varnish of an aprotic organic solvent such as toluene or xylene, 2,4,4 is used as an organic polyisocyanate as a raw material.
It is preferable that a mixture of -TDI and 2,6-TDI is used and the weight average molecular weight is 10,000 or less (average degree of polymerization is about 1 to 20). If the weight average molecular weight is too high, the solvent will not be easily dissolved, and the storage stability of the solution will be poor. 2,4
-The proportion of TDI and 2,6-TDI used is 100
In the case of a molar part, it is preferable to use 5 to 95 parts by mol of 2,4-TDI and 95 to 5 parts by mol of 2,6-TDI, and more preferably 60 to 90 parts by mol of 2,4-TDI and 2,6
It is more preferable to use 40 to 10 parts by mol of TDI, and in this case, a higher concentration solution containing 30% by weight or more of the carbodiimide copolymer can be obtained. On the other hand, if the addition ratio of 2,6-TDI is 5 mol parts or less, the storage stability of the varnish deteriorates, such as partial precipitation of the solution after several days.

When polycarbodiimide is used as a powder, various organic polyisocyanates can be used as a raw material. However, in performing melt molding, diphenylmethane-4,4′-diisocyanate is used as an organic polyisocyanate. The weight average molecular weight is preferably 20,000 or less (average degree of polymerization of about 1 to 20). Examples of the organic polyisocyanate as a raw material when used as a varnish include 1-methoxybenzene-2,4-diisocyanate in addition to 2,4-TDI and 2,6-TDI described above.
Examples thereof include 1-chlorophenylene diisocyanate.

Examples of the organic polyisocyanate as a raw material when used as a powder include phenylene-1,3-diisocyanate and phenylene-1,4 in addition to diphenylmethane-4,4'-diisocyanate.
-Diisocyanate, tetrachlorophenylene diisocyanate, meta-xylylene diisocyanate, para-xylylene diisocyanate, diphenyl sulfide-4
4'-diisocyanate, diphenylsulfone-4
4'-diisocyanate, diphenyl ether-4
4'-diisocyanate, diphenyl ether-3
4'-diisocyanate, diphenylketone-4,4 '
-Diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 2,4'-biphenyl diisocyanate, 4,4'-biphenyl diisocyanate, 3,3'-methoxy- 4,4'-biphenyl diisocyanate, anthraquinone-2,6-diisocyanate, triphenylmethane-4,4'-diisocyanate, azobenzene-4,4'-diisocyanate and dinuclear or higher polynuclear compounds of these organic polyisocyanates; Examples thereof include terminal isocyanate prepolymers obtained by using an organic polyisocyanate in stoichiometric excess with respect to the polyfunctional active hydrogen compound.

In the present invention, it is preferable to use a polycarbodiimide having a regulated molecular weight, since the thermal fluidity becomes better. The polycarbodiimide having a regulated molecular weight can be produced from the organic polyisocyanate and an organic monoisocyanate as a molecular weight regulator in the presence of a catalyst for promoting carbodiimidation of isocyanate.

Examples of the organic monoisocyanate used as a molecular weight modifier include phenyl isocyanate, (ortho, meta, para) -tolyl isocyanate, dimethylphenyl isocyanate, cyclohexyl isocyanate, methyl isocyanate, butyl isocyanate, chlorophenyl isocyanate, and trifluoromethylphenyl. Isocyanate, naphthyl isocyanate and the like can be exemplified, and 5 to 50 mol parts can be used per 100 mol parts of the organic polyisocyanate. Various catalysts can be used as a catalyst for promoting the carbodiimidation of isocyanate, but 1-phenyl-2-phospholene-1 can be used.
-Oxide, 3-methyl-1-phenyl-2-phospholene-1-oxide, 1-phenyl-2-phospholene-1
-Sulfide, 1-ethyl-2-phospholene-1-oxide, 1-ethyl-3-methyl-2-phospholene-1-
Oxides and their corresponding isomers, 3-phospholenes, are preferred. The amount of catalyst can be used between 0.01 and 1% based on the total amount of isocyanate.

In the present invention, the phenol derivative having two or more allyl groups in the molecule is, for example, a compound represented by the general formula (V)
It is a compound represented by I).

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In the composition of the present invention, the allyl group-containing phenol derivative used as the component (B) is not particularly limited as long as it has a structure represented by the general formula (VI). For example, 3,3′-diallyl-4,4′-dihydroxybiphenyl, bis (3-allyl-4-hydroxyphenyl)
Methane, 2,2-bis (3-allyl-4-hydroxyphenyl) propane, bis (3-allyl-4-hydroxyphenyl) ether, bis (3-allyl-4-hydroxyphenyl) thioether, bis (3-allyl) -4-hydroxyphenyl) sulfone, tris (3-allyl-4)
-Hydroxyphenyl) phosphite, tris (3-allyl-4-hydroxyphenyl) phosphate, and an allyl group-containing hydroxy compound of a polynuclear benzene obtained by reacting a phenol resin with an allyl halide. From the viewpoint of being easily available and giving good properties to the moldability and the final resin, 2,2
2 such as -bis (4-hydroxyphenyl) propane
Phenol derivatives having two allyl groups derived from polyhydric phenols are particularly preferably used. Further, a phenol derivative having an allyl group obtained by reacting an allyl halide with an initial condensate of phenol and formaldehyde is also useful.

In the composition of the present invention, the above-mentioned phenol derivative having an allyl group may be used alone, or a mixture thereof may be used. The blending ratio of the polycarbodiimide compound of the present invention and the phenol derivative having an allyl group is useful in a wide range of 95: 5 to 40:60 by weight, but is particularly preferably used in the range of 90:10 to 50:50. The composition ratio of the two components is preferably determined according to the desired use of the final cured resin and the required properties. If the polycarbodiimide content is less than 40% by weight, the excellent heat resistance inherent in polycarbodiimide is impaired. If it is used in an amount of 95% by weight or more, the effects of improving the fluidity during melting and shortening the curing time, which are the objects of the present invention, cannot be obtained. The composition of the present invention is easily cured by external heating, but if necessary, a curing catalyst or a curing accelerator is added, and the molding temperature or the molding time is controlled according to the molding method or the shape of the molded article. be able to.
At this time, as a curing catalyst or a curing accelerator to be used, for example, tertiary amines such as triethylenediamine, N, N-dimethylbenzylamine, N-methylmorpholine,
-Methylimidazole, 2-phenylimidazole, 2
Imidazoles such as -ethyl-4-methylimidazole, azo compounds such as azobisisobutyronitrile, t-
Organic peroxides such as butyl perbenzoate, dicumyl peroxide, benzoyl peroxide and the like can be mentioned.

The composition of the present invention can be prepared by using a suitable solvent, for example,
It can also be dissolved or suspended in chloroform, perclene, THF, toluene, xylene, NMP or the like and used as a varnish.

If desired, inorganic fillers and reinforcing fibers,
For example, crushed silica, synthetic silica, alumina powder, mica,
Titania or glass fiber, carbon fiber, aramid fiber, boron fiber, etc. can be added, and furthermore, an internal release agent such as natural wax, synthetic wax, organic fatty acid, metal salt of organic fatty acid, halogen compound, oxidation Flame retardants such as antimony and coloring agents such as carbon black can be added according to the purpose.

The thermosetting resin of the present invention can be prepared by injection molding, transfer molding, extrusion molding, compression molding, etc.
It is molded by a known molding method and put to practical use. When a thermosetting resin is used as a varnish, it can be applied to the production of a known laminate.

[0022]

The present invention will now be described in more detail with reference to examples. The physical properties of the polymers obtained in Examples and Comparative Examples were measured by the following methods. 5% decomposition temperature: Using a thermogravimetric analyzer (TGA), the 5% weight loss temperature of the polymer was measured in air at a heating rate of 10 ° C./min. Glass transition temperature: The glass transition temperature was measured by a thermal mechanical analyzer (TMA) by an expansion method at a heating rate of 5 ° C./min. Kinematic viscosity: measured by applying a load of 100 kgf / cm ² after preheating at a predetermined temperature for 1 minute using a Koka type flow tester (manufactured by Shimadzu). Pencil hardness: The surface hardness of the cured film was measured according to JIS K5400.

Examples 1-5 Diphenylmethane-4,4'-diisocyanate and phenylisocyanate were converted to 3-methyl-1-phenyl-2-
A phenol derivative having an allyl group (BAHP, BAHP) is prepared by heating in xylene in the presence of a phosphorene-1-oxide catalyst, and heating to a molecular weight-controlled powdered polycarbodiimide (hereinafter abbreviated as PCI; weight average molecular weight of about 8,000). (DAHB, BAHS) in Table 1 were added and mixed well to obtain a powdery resin composition. In order to evaluate the melt fluidity of these powdery resin compositions,
The kinematic viscosity was measured. Next, these resin compositions were added to 25
By performing pressure molding at 0 ° C. for a predetermined time, a red-brown transparent resin molded product and a cured film were obtained. Table 1 shows the physical property values of the obtained molded articles.

[0024]

[Table 1]

Comparative Example 1 A fluidity was evaluated by kinematic viscosity measurement in the same manner as in Example 1 except that a phenol derivative having an allyl group was not used, and a molded product was obtained by press molding at 250 ° C. for 30 minutes. . As shown in Table 2, when the PCI powder alone is used, the physical properties of the molded product are lower than those of the PCI composition to which a phenol derivative having an allyl group is added, such as a low glass transition temperature and a low pencil hardness. Physical properties.

Comparative Examples 2 and 3 Example 1 except that an active hydrogen compound (BPA, MDA) was used instead of the phenol derivative having an allyl group.
A composition was prepared in the same manner as described above. The fluidity was evaluated by measuring the kinematic viscosity, and a molded product was obtained by pressure molding at 250 ° C. for 30 minutes. As shown in Table 2, the kinematic viscosity measurement shows that the PCI composition to which the active hydrogen compound is added does not show any fluidity, has extremely poor fluidity, and has a low 5% decomposition temperature.

[0027]

[Table 2]

Example 6 A mixture of 80 mol parts of 2,4-TDI and 20 mol parts of 2,6-TDI (trade name: TDI 80, Mitsui Toatsu Chemicals, Inc.)
92 g) and 9 g of phenyl isocyanate are dissolved in toluene, 0.36 g of 3-methyl-1-phenyl-2-phospholene-1-oxide catalyst is added, polymerization is carried out at 110 ° C., and polycarbodiimide having a controlled molecular weight is obtained. A resin varnish was obtained (average molecular weight: about 1000, solid content: 30 wt%). BAHP was added to this varnish in an amount of 19 g and uniformly dissolved to prepare a composition varnish (weight ratio: 80/2).
0). The resulting composition varnish was cast on a glass plate and dried at 120 ° C. for 3 hours to obtain a film. This film was heat-treated at 250 ° C. for 30 minutes to obtain a cured film. Its physical properties were as follows. 5% decomposition temperature 473 ° C Pencil hardness 4H

Comparative Example 4 A cured film was obtained in the same manner as in Example 6, except that BAHP was not used. The 5% decomposition temperature of this cured film was 488 ° C. and softened at around 40 ° C. The cured film had a pencil hardness of H, and did not have sufficient physical properties as a thermosetting resin.

[0030]

As described above, the thermosetting composition of the present invention contains a polycarbodiimide compound and a phenol derivative having an allyl group, and has good fluidity when dissolved by heating. , And is easily cured, but has greatly improved the heat resistance, curing time, and varnish utility of the polymer of the compound having a carbodiimide bond as a raw material, and has an extremely large industrial utility value. .

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Akihiro Yamaguchi 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Mitsui Toatsu Chemicals Co., Ltd. (56) References JP-A-6-107945 (JP, A) JP-A-61 −235415 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 18/00-18/87 C08K 5/105 C08L 79/08

Claims (5)

(57) [Claims] 1. A polycarbodiimide compound having two or more carbodiimide bonds in a molecule, and (B)
A thermosetting resin composition comprising a phenol derivative having at least two or more allyl groups in a molecule as an essential component. 2. The polycarbodiimide compound is composed of 5 to 95 equivalents of a group having a structural unit represented by the following formula (I) and 95 to 95 parts by weight of a group having a structural unit represented by the following formula (II).
2. The thermosetting resin composition according to claim 1, wherein the thermosetting resin composition is a carbodiimide copolymer containing 5 equivalent parts, the terminal of the polymer molecule is sealed with an aromatic group, and the weight average molecular weight is 10,000 or less. . Embedded image Embedded image 3. The polycarbodiimide compound, wherein the aromatic group at the molecular terminal is a phenyl group, an ortho-tolyl group, a meta-tolyl group, a para-tolyl group, a dimethylphenyl group, a chlorophenyl group, a trifluoromethylphenyl group, a naphthyl group. 3. The thermosetting resin composition according to claim 1, wherein the carbodiimide copolymer is at least one selected from the group consisting of isopropylphenyl group and diisopropylphenyl group. 4. A polycarbodiimide compound represented by the following formula (I)
2. The thermosetting resin composition according to claim 1, wherein the weight average molecular weight represented by II) is 20,000 or less. Embedded image 5. A phenol derivative having an allyl group,
The thermosetting resin composition according to claim 1, which is represented by the following formula (IV). Embedded image