KR20180124877A - A maleimide resin, a curable resin composition, and a cured product thereof - Google Patents

Abstract

[식 중, X는 탄소수 6∼18개의 방향족 탄화수소기를 나타낸다. 복수 존재하는 R₁은 각각 독립적으로 수소원자, 탄소수 1∼10개의 알킬기 또는 방향족기를 나타낸다. m은 1∼4의 정수를 나타내고, n은 1∼10의 실수를 나타낸다.]The present invention provides a maleimide resin having a small amount of amide acid in an unmixed ring and curing the curable resin composition using the same to provide a cured product having excellent thermal decomposability, flame retardance, low hygroscopicity and strength. The maleimide resin has an acid value represented by the following formula (1) of 5 mgKOH / g or less.

Wherein X represents an aromatic hydrocarbon group having 6 to 18 carbon atoms. The plurality of R _{1 s} present each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aromatic group. m represents an integer of 1 to 4, and n represents a real number of 1 to 10.]

Description

A maleimide resin, a curable resin composition, and a cured product thereof

TECHNICAL FIELD The present invention relates to a high-quality maleimide resin, a curable resin composition using the same, and a cured product thereof. More particularly, the present invention relates to an electric / electronic part such as a semiconductor sealing material, a printed wiring board, It is suitably used for lightweight high strength materials.

Background Art [0002] In recent years, laminated boards on which electric / electronic parts are mounted have been widely and more sophisticated due to the expansion of their fields of use. For example, conventional semiconductor chips are mainly mounted on lead frames made of metal, but semiconductor chips having a high processing capability such as CPUs are often mounted on a laminate made of a polymer material. As the speed of devices such as a CPU increases and the clock frequency increases, signal propagation delay and transmission loss become a problem, and a low dielectric constant and a low dielectric loss tangent are required in a wiring board. At the same time, as the speed of the device is increased, the heat generation of the chip is increased, so that it is necessary to increase the heat resistance. In recent years, mobile electronic devices such as mobile phones have been in widespread use, and since precision electronic devices have been used and carried in outdoor environments and in the vicinity of the human body, resistance to external environments do. Furthermore, in the field of automobiles, the progress of electronics is rapidly proceeding, and precision electronic equipment is placed in the vicinity of the engine, and heat and moisture resistance are required to be higher. On the other hand, safety for flame resistance and the like has become even more important because it is used for automobile applications and portable devices. However, since the use of halogen-based flame retardants is avoided due to recent improvements in environmental awareness, The need to give more than one.

Conventionally, for example, a wiring board using a BT resin, which is a resin using a combination of a bisphenol A cyanate ester compound and a bismaleimide compound as in Patent Document 1, is widely used as a high-performance wiring board because of its excellent heat resistance, chemical resistance, However, as described above, improvement is required under circumstances in which higher performance is required.

In addition, the weight saving of airplanes, automobiles, trains, ships and the like is progressing in recent years due to the need for energy saving. In the past, studies have been made especially in the field of transportation equipment to substitute lightweight, high-strength carbon fiber composite materials that have been using metal materials. For example, in Boeing 787, the weight ratio is increased by increasing the ratio of the composite material, thereby remarkably improving the fuel efficiency. In the field of aviation, for the sake of lighter weight, there is also a movement of introducing a carbon fiber composite material into the members around the engine, and a high level of heat resistance is naturally demanded. In the field of automobiles, propeller shafts made of composite materials are mounted, but there is also a movement to manufacture a car body as a composite material for luxury cars. In the field of carbon fiber composite materials, a composite material using bisphenol A diglycidyl ether, tetraglycidyldiaminodiphenyl methane and the like as an epoxy resin and diaminodiphenyl methane, diaminodiphenyl sulfone as a curing agent has been used However, it is necessary to expand the application of the composite material in order to achieve lighter weight and higher internal resistance, and as a material thereof, maleimide resin is considered as one means.

In this case, the maleimide compound available in the market is often a bismaleimide compound, and since it is a crystal having a high melting point, it is necessary to use it as a solution form. However, they are difficult to dissolve in general-purpose organic solvents and have drawbacks such as solubility in only a high-boiling, hygroscopic solvent such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone. Further, the cured product of the bismaleimide compound has a defect that the heat resistance is good, but is easily broken and the moisture absorption amount is large.

On the other hand, as in Patent Documents 2, 3 and 4, a maleimide resin having a molecular weight distribution and a relatively low softening point and excellent solvent solubility has been developed. The cured product has flexibility with heat resistance , And low hygroscopicity has also been reported.

On the other hand, in the maleimide compound, as described in Patent Document 5, when the amount of the impurities in the maleimide is large, the pot life of the varnish becomes short, the heat resistance of the cured product deteriorates and the impact resistance becomes small, The drawbacks are pointed out. Further, in Patent Document 6, it is pointed out that when an unactivated amide acid or the like is contained as an impurity, the heat resistance of the cured product is lowered, and wiring corrosion becomes a problem when used as an electrical insulating material. As a method for reducing impurities, Patent Document 5 discloses a method of precipitating by adding water to a bismaleimide solution to lower the solubility of a solvent, adding a basic compound to the suspension, treating the resultant mixture, filtering the resultant mixture, Lt; / RTI > In addition, Patent Document 6 discloses a method of adding impure solvents such as alcohols and aliphatic solvents to a bismaleimide solution to lower the solubility of the solvent to precipitate, or to wash the cake to reduce impurities.

Japanese Patent Publication No. 54-30440 Japanese Unexamined Patent Application Publication No. 3-100016 Japanese Patent Publication No. Hei 8-16151 Japanese Patent Application Laid-Open No. 2009-001783 Japanese Patent Application Laid-Open No. 55-13234 Japanese Patent Laid-Open No. 1-211563 Japanese Patent Application Laid-Open No. 2005-264154

On the other hand, in the case of a maleimide resin having excellent solvent solubility as described above, even if precipitation is tested by adding a poor solvent or water, it is not formed into a crystal or a powder form and becomes large lumps, so that filtration can not be performed, There is a problem such as generation of a large amount of wastewater. Therefore, it is difficult to obtain a high-purity maleimide resin because the conventional impurity reduction method can not be used.

An object of the present invention is to provide a maleimide resin having a small amount of amide acid in an unreacted ring in order to improve thermal decomposition property, flame retardance, low hygroscopicity and strength of a curable resin composition containing a maleimide resin.

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have completed the present invention.

That is,

[One]

A maleimide resin having an acid value of 5 mgKOH / g or less represented by the following formula (1)

(In the formula, X represents a group of 6-18 carbon atoms, an aromatic hydrocarbon group. R ₁ to multiple presence each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or aromatic. M represents an integer of 1~4, n Represents a real number from 1 to 10.)

[2]

The maleimide resin as described in [1], which is represented by the following formula (2)

M represents an integer of 1 to 4, and n represents a real number of 1 to 10.) In the formula, R < ₁ > represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aromatic group.

[3]

A maleimide resin as described in [1], which is represented by the following formula (3)

M represents an integer of 1 to 4, and n represents a real number of 1 to 10.) In the formula, R < ₁ > represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aromatic group.

[4]

An aromatic amine resin is reacted with maleic acid or maleic anhydride to produce an amide acid, followed by a dehydration reaction in the presence of a catalyst, and excess maleic acid or maleic anhydride is removed by washing with water. Thereafter, dehydration The maleimide resin according to any one of the above items [1] to [3]

[5]

A curable resin composition containing the maleimide resin according to any one of the items [1] to [4]

[6]

A cured product obtained by curing the curable resin composition described in [5]

[7]

An aromatic amine resin is reacted with maleic acid or maleic anhydride to produce an amide acid, followed by a dehydration reaction in the presence of a catalyst, and excess maleic acid or maleic anhydride is removed by washing with water. Thereafter, dehydration A method for producing a maleimide resin represented by the following formula (1) which undergoes ring closure reaction,

(In the formula, X represents a group of 6-18 carbon atoms, an aromatic hydrocarbon group. R ₁ to multiple presence each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or aromatic. M represents an integer of 1~4, n Represents a real number from 1 to 10.)

.

The maleimide resin having a small amount of the unmodified cyclic amide acid of the present invention can improve the thermal decomposition property, flame retardance, low hygroscopicity and strength of the cured product of the curable resin composition using the same.

Hereinafter, the present invention will be described in detail. First, for ease of explanation, the method for producing the maleimide resin of the present invention will be described.

(Production method of aromatic amine resin)

The maleimide resin of the present invention may be an aromatic amine resin of the following formulas (4) to (6) as a precursor.

(In the formula, X represents a group of 6-18 carbon atoms, an aromatic hydrocarbon group. R ₁ to multiple presence each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or aromatic. M represents an integer of 1~4, n Represents a real number from 1 to 10.)

M represents an integer of 1 to 4, and n represents a real number of 1 to 10.) In the formula, R < ₁ > represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aromatic group.

M represents an integer of 1 to 4, and n represents a real number of 1 to 10.) In the formula, R < ₁ > represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aromatic group.

The production method of the aromatic amine resin represented by the above formulas (4) to (6) is not particularly limited. For example, Patent Document 3 describes the reaction of an aniline derivative with a bishalogenomethylaralkyl derivative or an aralkyl alcohol derivative However, aromatic amines of the formulas (4) to (6) are obtained by reacting an aniline derivative with a bishalogenomethylaralkyl derivative or an aralkyl alcohol derivative by employing such a method.

Examples of the aniline derivative to be used include aniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 2-ethylaniline, 3-ethylaniline, 4-ethylaniline, 2,3-dimethylaniline, , 2,5-dimethylaniline, 2,6-dimethylaniline, 3,4-dimethylaniline, 3,5-dimethylaniline, 2-propylaniline, 3-propylaniline, 4-propylaniline, Butyl aniline, 4-sec-butylaniline, 4-sec-butyl aniline, 4-tert-butyl aniline, 2- Diethylaniline, 2,6-diethylaniline, 2-isopropyl-6-methylaniline, 4-aminobutyric acid, Phenyl and the like. These may be used alone or in combination of two or more.

Examples of bishalogenomethylaralkyl derivatives or aralkyl alcohol derivatives to be used include 1,4-bischloromethylbenzene, 1,3-bischloromethylbenzene, 1,2-bischloromethylbenzene, 1,4-bisbromo Methylbenzene, 1,3-bisbromomethylbenzene, 1,2-bisbromomethylbenzene, 1,4-dimethoxymethylbenzene, 1,3-dimethoxymethylbenzene, 1,2-dimethoxymethylbenzene, 1,4-diethoxymethylbenzene, 1,3-diethoxymethylbenzene, 1,2-diethoxymethylbenzene, 1,4-dihydroxymethylbenzene, 1,3-dihydroxymethylbenzene, 1,2 - dihydroxymethylbenzene, 2,6-dihydroxymethylnaphthalene, 1,5-dihydroxymethylnaphthalene, 2,6-dimethoxymethylnaphthalene, 1,5-dimethoxymethylnaphthalene, 4,4'- Bis (bromomethyl) biphenyl, 4,4'-bis (fluoromethyl) biphenyl, 4,4'-bis (iodomethyl) biphenyl, 4,4'-dimethoxymethylbiphenyl, 4,4'-diethoxymethylbiphenyl, 4,4'-dipropoxymethylbiphenyl, 4,4'-di 4,4'-diisobutoxymethylbiphenyl, 4,4'-diisobutoxymethylbiphenyl, 4,4'-di-tert-butoxymethylbiphenyl, 4,4'- Dihydroxymethylbiphenyl and the like. These may be used alone or in combination of two or more.

The bishalogenomethylaralkyl derivative or the aralkyl alcohol derivative is used in an amount of 0.05 to 0.8 mol, preferably 0.1 to 0.6 mol, per mol of the aniline derivative used.

In the reaction, acidic catalysts such as hydrochloric acid, phosphoric acid, sulfuric acid, formic acid, zinc chloride, ferric chloride, aluminum chloride, p-toluenesulfonic acid and methanesulfonic acid may be used as necessary. These may be used alone or in combination of two or more. The amount of the catalyst to be used is 0.1 to 0.8 mol, preferably 0.5 to 0.7 mol, relative to 1 mol of the aniline used. If the amount is too large, the viscosity of the reaction solution becomes excessively high and stirring becomes difficult. .

The reaction may be carried out in an organic solvent such as toluene or xylene as needed or in a solvent. For example, after an acid catalyst is added to a mixed solution of an aniline derivative and a solvent, water is removed from the system by azeotropy when the catalyst contains water. Then, a bishalogenomethylaralkyl derivative or an aralkyl alcohol derivative is added over a period of 1 to 5 hours, preferably 2 to 4 hours, at 40 to 100 ° C, preferably 50 to 80 ° C, And the reaction is carried out at 180 to 240 캜, preferably 190 to 220 캜, for 5 to 30 hours, preferably 5 to 20 hours. After completion of the reaction, the acidic catalyst is neutralized in an aqueous alkaline solution, and then water-insoluble organic solvent is added to the oil layer to wash the water until the wastewater becomes neutral, and then the solvent and the excess aniline derivative are removed under reduced pressure.

Since the diphenylamine derivative is a by-product depending on the kind of the aniline derivative, the diphenylamine derivative is contained in an amount of 1% by weight or less, preferably 0.5% by weight or less, more preferably 0.5% by weight or less, in a high temperature and high vacuum state or by means of steam distillation By weight to 0.2% by weight or less.

The maleimide resin of the present invention is obtained by reacting an aromatic amine resin represented by the formula (4) - (6) obtained by the above process with maleic acid or maleic anhydride (hereinafter also referred to as "maleic anhydride" Or in the presence of a base.

Since the solvent used in the reaction needs to remove water produced during the reaction from the system, a non-aqueous solvent is used. For example, aliphatic solvents such as toluene and xylene, aliphatic solvents such as cyclohexane and n-hexane, ethers such as diethyl ether and diisopropyl ether, ester solvents such as ethyl acetate and butyl acetate and aliphatic solvents such as methyl isobutyl ketone , And cyclopentanone. However, the solvent is not limited to these solvents, and two or more solvents may be used in combination.

In addition to the above-mentioned non-water-soluble solvent, an aprotic polar solvent may be used in combination. For example, dimethylsulfone, dimethylsulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, N-methyl-2-pyrrolidone and the like, May be used together. When an aprotic polar solvent is used, it is preferable to use one having a higher boiling point than the non-water-soluble solvent used in combination.

The catalyst used in the reaction is not particularly limited, and examples thereof include p-toluenesulfonic acid, hydroxy-p-toluenesulfonic acid, methanesulfonic acid, sulfuric acid, and phosphoric acid. The amount of the acid catalyst to be used is usually 0.1 to 10% by weight, preferably 1 to 5% by weight based on the aromatic amine resin.

For example, an aromatic amine resin represented by the formula (4) to (6) is dissolved in toluene and N-methyl-2-pyrrolidone, maleic anhydride is added thereto to produce an amide acid, Toluenesulfonic acid is added and the reaction is carried out while removing water produced under reflux conditions from the system.

Alternatively, maleic anhydride is dissolved in toluene, and an N-methyl-2-pyrrolidone solution of an aromatic amine resin represented by the formula (4) to (6) is added under stirring to form an amide acid, Toluenesulfonic acid is added and the reaction is carried out while removing water produced under reflux conditions from the system.

Alternatively, maleic anhydride is dissolved in toluene, p-toluenesulfonic acid is added, and an N-methyl-2-pyrrolidone solution of the aromatic amine resin of the formula (4) to the formula (6) The water which is azeotropic in the middle is removed to the outside of the system while the toluene is returned to the inside of the system.

In any of these methods, maleic anhydride is used in an amount of usually 1 to 3 times, preferably 1.2 to 2.0 times, based on the amino group of the aromatic amine resin of the above formulas (4) to (6).

For the purpose of the present invention, in order to reduce the amount of amide acid in the unreacted ring, water is added to the reaction solution after the maleimidation reaction described above to separate into a resin solution layer and an aqueous layer, and excess maleic acid, maleic anhydride, Since polar solvents and catalysts are dissolved in the water layer side, they are separated and removed, and the same operation is repeated to thoroughly remove excess maleic acid, maleic anhydride, aprotic polar solvent and catalyst. The catalyst is added again to the maleimide resin solution of the excess of maleic acid or maleic anhydride, the aprotic polar solvent and the organic layer from which the catalyst has been removed, and the dehydration ring closure reaction of the residual amide acid under the reflux condition is carried out again, (Second stage reaction). ≪ tb > < TABLE >

The time for the re-dehydration ring closure reaction is usually 1 to 5 hours, preferably 1 to 3 hours. If necessary, the above-mentioned aprotic polar solvent may be added. After completion of the reaction, the reaction mixture is cooled, and washing is repeated until the water becomes neutral. Thereafter, water may be removed by azeotropic dehydration under heating and reduced pressure, and then the solvent may be distilled off or an additional solvent may be added to adjust the resin solution to a desired concentration. The solvent may be completely distilled off to obtain a solid resin .

Next, the maleimide resin of the present invention will be described.

The maleimide resin of the present invention obtained by the above-mentioned production method has the structure of the following formula (1) having an acid value of 5 mgKOH / g or less.

(In the formula, X represents a group of 6-18 carbon atoms, an aromatic hydrocarbon group. R ₁ to multiple presence each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or aromatic. M represents an integer of 1~4, n Represents a real number from 1 to 10.)

Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms represented by X in the above formula (1) include a phenyl group, a biphenyl group, and a terphenyl group. Preferably a phenyl group or a biphenyl group, more preferably a biphenyl group.

Specifically, a maleimide resin having a structure represented by the following formula (2) or (3) is preferable.

M represents an integer of 1 to 4, and n represents a real number of 1 to 10.) In the formula, R < ₁ > represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aromatic group.

M represents an integer of 1 to 4, and n represents a real number of 1 to 10.) In the formula, R < ₁ > represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aromatic group.

Examples of the alkyl group having 1 to 10 carbon atoms represented by R ₁ in the formulas (1) to (3) include methyl group, ethyl group, n-propyl group, isopropyl group, n- butyl group, isobutyl group, An n-pentyl group, an i-pentyl group, an amyl group, an n-hexyl group, a cyclopentyl group, a cyclohexyl group, an octyl group, a 2-ethylhexyl group, a nonyl group, .

Examples of the aromatic group in R ₁ in the formulas (1) to (3) include an aromatic hydrocarbon group such as a phenyl group, biphenyl group, indenyl group, naphthyl group, anthryl group, fluorenyl group and pyrenyl group, An imidazolyl group, a pyridyl group, a pyrazyl group, a pyrimidyl group, a quinolyl group, an indolyl group and a carbazolyl group, and the like.

It is also preferable that the average value of n is 1 < n. The value of n can be calculated from the value of the number average molecular weight obtained by measuring the gel permeation chromatography (GPC) of the maleimide resin. The value of n can be approximately calculated by GPC It can be considered that the value of n calculated from the measurement result of Fig.

The maleimide resin of the present invention has an acid value of 5 mgKOH / g or less, preferably 4 mgKOH / g, more preferably 3 mg / KOH or less. The acid value can be measured by a method according to JIS K-0070: 1992.

If amide acid or the like having an unreacted ring is contained as an impurity, if the acid value is more than 5 mgKOH / g, the heat resistance of the cured product is lowered, and when used as an electric insulating material, there is a case of wiring corrosion.

As the maleimide resin of the present invention, those having a melting point and a softening point can be used. Particularly, when it has a melting point, it is preferably 200 DEG C or lower, and when it has a softening point, it is preferably 150 DEG C or lower.

When the melting point or the softening point is too high, the possibility of gelation at the time of mixing with a later epoxy resin increases, which is not preferable.

The melt viscosity of the maleimide resin of the present invention at 150 ° C is usually 0.05 to 100 Pa · s, preferably 0.1 to 40 Pa · s.

Next, the curable resin composition of the present invention will be described.

The curable resin composition of the present invention may contain a compound capable of undergoing a crosslinking reaction with the maleimide resin of the present invention. Examples of the compound include a functional group capable of crosslinking with a maleimide resin such as an amino group, a cyanate group, a phenolic hydroxyl group, an alcoholic hydroxyl group, an allyl group, a methacrylic group, an acrylic group, a methacrylic group, a vinyl group, Or a structure) is not particularly limited.

Since the amine compound and the maleimide compound undergo a crosslinking reaction, the aromatic amine resin represented by the above formulas (4) to (6) may be used. Since the maleimide resin can be self-polymerized, it can be used alone. An amine compound other than the aromatic amine resin described in the above formulas (4) to (6) or a maleimide compound other than the maleimide resin of the present invention may be used in combination.

The content of the maleimide resin in the curable resin composition of the present invention is usually 10% by weight or more, preferably 15% by weight or more, and more preferably 20% by weight. In the above range, the physical properties of the cured product tend to be high in mechanical strength, peel strength, and heat resistance.

As the amine compound that can be compounded in the curable resin composition of the present invention, an amine compound of the prior art can be used. Specific examples of the amine compound include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, m-xylenediamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, diethylaminopropylamine, isophoronediamine, 1,3 (4-aminocyclohexyl) methane, bis (4-aminocyclohexyl) methane, norbornenediamine, 1,2-diaminocyclohexane, diaminodiphenylmethane , Methanophenylenediamine, diaminodiphenylsulfone, dicyandiamide, polyoxypropylenediamine, polyoxypropylenetriamine, N-aminoethylpiperazine, aniline-formalin resin, and the like, but are not limited thereto . These may be used alone or in combination of two or more.

As the maleimide compound that can be incorporated into the curable resin composition of the present invention, conventionally known maleimide compounds can be used. Specific examples of the maleimide compound include 4,4'-diphenylmethane bismaleimide, polyphenylmethane maleimide, m-phenylene bismaleimide, 2,2'-bis [4- (4-maleimidophenoxy) phenyl ] Propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, (3-maleimidophenoxy) benzene, 1,3-bis (4-maleimidophenoxy) benzene, and the like can be used. But are not limited to these. These may be used alone or in combination of two or more. The blending amount of the maleimide compound is preferably 5 times or less, and more preferably 2 times or less, in the weight ratio of the maleimide resin of the present invention.

As the cyanate ester compound that can be incorporated into the curable resin composition of the present invention, conventionally known cyanate ester compounds can be used. Specific examples of the cyanate ester compound include polycondensates of phenols and various aldehydes, polycondensates of phenols and various diene compounds, polycondensates of phenols and ketones, polycondensates of bisphenols and various aldehydes, and the like, with cyanate esters Compounds, but are not limited thereto. These may be used singly or two or more of them may be used.

Examples of the phenol include phenol, alkyl substituted phenol, aromatic substituted phenol, naphthol, alkyl substituted naphthol, dihydroxybenzene, alkyl substituted dihydroxybenzene, and dihydroxynaphthalene.

Examples of the various aldehydes include formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthalaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde and cinnamaldehyde.

Examples of the various diene compounds include dicyclopentadiene, terpene, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, Isoprene and the like.

Examples of the ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, and benzophenone.

The cyanate ester compound in which the synthesis method is described in Japanese Patent Application Laid-Open No. 2005-264154 is particularly preferable as a cyanate ester compound because of its low hygroscopicity, flame retardance and dielectric properties.

Examples of the compound having an allyl group or a metallyl group that can be incorporated into the curable resin composition of the present invention include (meth) allyl compounds such as 4,4'-bisphenol A diallyl ether, 4,4'-bisphenol F diallyl (Meth) allyl isocyanurate, 2,2-di (4-acetyloxy-3- (meth) allylphenyl) propane, di (Meth) allylphenyl) methane, di (4-acetyloxy-3- (meth) allylphenyl) sulfone, 2,2- Di (4-benzoyloxy-3- (meth) allylphenyl) methane, di (4-benzoyloxy- (Meth) allylphenyl) sulfone, 2,2-di (4-toluoyloxy-3- Propanyloxy-3- (meth) allylphenyl) methane, di (4-propionyloxy-3- (Meth) allylphenyl) sulfone, 2,2-di (4-butyryloxy-3- Phenyl) propane allyl chloride, allyl alcohol, allyl ethyl ether, allyl-2-hydroxyethyl ether, allyl glycidyl ether, methallyl glycidyl ether, diallyl phthalate, trimethylolpropane diallyl ether, pentaerythritol tri Allyl ether, and triallyl isocyanurate.

In the curable resin composition of the present invention, an epoxy resin can be further blended. As the epoxy resin which can be blended, any of conventionally known epoxy resins can be used. Specific examples of the epoxy resin include polycondensates of phenols and various aldehydes, polymerizates of phenols and various diene compounds, polycondensates of phenols and ketones, polycondensates of bisphenols and various aldehydes, alcohols and the like, glycidyl ether epoxy Resin, an alicyclic epoxy resin represented by 4-vinyl-1-cyclohexene diepoxide or 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate, tetraglycidyldiaminodi Glycidylamine-based epoxy resins typified by phenylmethane (TGDDM) and triglycidyl-p-aminophenol, glycidyl ester-based epoxy resins, and the like, but are not limited thereto. These may be used alone, or two or more of them may be used.

Further, an epoxy resin obtained by subjecting a phenol aralkyl resin obtained by the condensation reaction of a bishalogenomethylaralkyl derivative or an aralkyl alcohol derivative to a dehydrochlorination reaction with epichlorohydrin as a raw material is used as a low hygroscopicity, It is particularly preferable as an epoxy resin because of its excellent properties.

When the epoxy resin is blended, the blending amount is not particularly limited, but is preferably 0.1 to 10 times, and more preferably 0.2 to 4 times, the weight ratio of the maleimide resin. When the blending amount of the epoxy resin is less than 0.1 times the maleimide resin, the cured product may be easily broken. When the blending amount is more than 10 times, the dielectric property may be lowered.

In the curable resin composition of the present invention, a compound having a phenol resin or an acid anhydride group can be further blended.

As the phenol resin which can be compounded, all conventionally known phenol resins can be used. Specific examples of the phenol resin include bisphenols (bisphenol A, bisphenol F, bisphenol S, biphenol, bisphenol AD and the like), phenols (phenol, alkyl substituted phenol, aromatic substituted phenol, naphthol, alkyl substituted naphthol, dihydroxybenzene, Dihydroxynaphthalene and the like) with various aldehydes (formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl substituted benzaldehyde, hydroxybenzaldehyde, naphthalaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde Etc.), polycondensates of phenols and various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisocyanate Propene biphenyl, butadiene, isoprene, etc.), phenols and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, Alpha], [alpha] ', [alpha]' - benzene dimethanol, biphenyl dimethanol, alpha, alpha, alpha ', alpha', and the like), polycondensation products of phenols and aromatic dimetholols (benzene dimethanol, -Biphenyl dimethanol), polycondensates of phenols and aromatic dichloromethyls (?,? '- dichloro xylene, bischloromethylbiphenyl, etc.), polycondensates of bisphenols and various aldehydes, and their modification Water, but is not limited thereto. These may be used alone, or two or more of them may be used.

The phenol aralkyl resin obtained by the condensation reaction of the phenols with the bishalogenomethylaralkyl derivative or the aralkyl alcohol derivative is particularly preferable as the phenol resin because of its low hygroscopicity, flame retardancy and dielectric properties.

As the compound having an acid anhydride group that can be compounded, all conventionally known compounds can be used. Specific examples of the compound having an acid anhydride group include 1,2,3,4-butanetetracarboxylic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride, 1,2,3,4-cyclo Cyclohexanetetracarboxylic acid dianhydride, pyromellitic anhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3- Cyclohexene-1,2-dicarboxylic acid anhydride, 4- (2,5-dioxotetrahydrofuran-3-yl) -1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylate Acid anhydrides and the like.

The compounds having an acid anhydride group may be used alone or in combination of two or more. When the acid anhydride group is reacted with an amine, it becomes an amidic acid. However, if it is further heated at 200 ° C to 300 ° C, it becomes an imide structure by a dehydration reaction and becomes a material having excellent heat resistance.

In the curable resin composition of the present invention, a curing catalyst (curing accelerator) may be added if necessary. Such as 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl- Imidazoles such as triethylamine, triethylenediamine, 2- (dimethylaminomethyl) phenol, 1,8-diaza-bicyclo (5,4,0) undecene -7, tris (dimethylaminomethyl) phenol and benzyldimethylamine, phosphines such as triphenylphosphine, tributylphosphine and trioctylphosphine, tin octylate, zinc octylate, dibutyltin dimale Organic peroxide such as zinc chloride, aluminum chloride and tin chloride, organic peroxides such as di-tert-butyl peroxide and dicumyl peroxide, azo compounds such as azobisisobutyronitrile, Azo compounds such as butyronitrile and azobisdimethylvaleronitrile, mines such as hydrochloric acid, sulfuric acid and phosphoric acid, Lewis acids such as boron trifluoride, And salts such as sodium oxide and lithium chloride. The blending amount of the curing catalyst is preferably 10 parts by weight or less, more preferably 5 parts by weight or less, based on 100 parts by weight of the total amount of the curable resin composition.

An organic solvent may be added to the curable resin composition of the present invention to form a varnish-like composition (hereinafter, simply referred to as a varnish). Examples of the solvent to be used include amides such as? -Butyrolactones, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide and N, N- Based solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether monoacetate, and propylene glycol monobutyl ether; Solvents, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone, and aromatic solvents such as toluene and xylene. The solvent is used in the range of the solid content concentration of usually 10 to 80% by weight, preferably 20 to 70% by weight, excluding the solvent in the obtained varnish.

Furthermore, known additives may be added to the curable resin composition of the present invention, if necessary. Specific examples of the usable additives include epoxy resin curing agents, polybutadiene and modified products thereof, modified products of acrylonitrile copolymer, polyphenylene ether, polystyrene, polyethylene, polyimide, fluororesin, maleimide compound, cyanate An inorganic filler such as an ester compound, a silicone gel, a silicone oil, and silica, alumina, calcium carbonate, quartz powder, aluminum powder, graphite, talc, clay, iron oxide, titanium oxide, aluminum nitride, asbestos, mica, Surface treating agents for fillers such as silane coupling agents, releasing agents, coloring agents such as carbon black, phthalocyanine blue and phthalocyanine green. The blending amount of these additives is preferably 1,000 parts by weight or less, more preferably 700 parts by weight or less, based on 100 parts by weight of the curable resin composition.

The method for preparing the curable resin composition of the present invention is not particularly limited, but the components may be uniformly mixed or prepolymerized. For example, by heating the maleimide resin and the cyanate ester compound in the presence or absence of a solvent in the presence or absence of a catalyst, or in the absence of a solvent. Likewise, the maleimide resin of the present invention and the epoxy resin, amine compound, maleimide compound, cyanate ester compound, phenol resin, acid anhydride compound and other additives may be optionally prepolymerized. For the mixing or prepolymerization of each component, for example, an extruder, a kneader, a roll or the like is used in the absence of a solvent, and a reaction vessel equipped with a stirring device is used in the presence of a solvent.

The prepreg can be obtained by heating and melting the curable resin composition of the present invention and lowering the viscosity to impregnate reinforcing fibers such as glass fiber, carbon fiber, polyester fiber, polyamide fiber and alumina fiber.

Further, the varnish may be impregnated into the reinforcing fiber and heated and dried to obtain a prepreg.

After the prepreg is cut in a desired form and optionally laminated with a copper foil or the like, the curable resin composition is heated and cured while applying pressure to the laminate by a press forming method, an autoclave forming method, a sheet winding forming method, A printed wiring board), or a carbon fiber reinforcement material.

Example

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. In the following description, &quot; part (s) &quot; and &quot;% &quot; The softening point and the melt viscosity were measured by the following methods.

· Softening point: Measured by the method according to JIS K-7234

· Melt viscosity: Viscosity at 150 ° C by cone plate method

· Acid value: Measured according to JIS K-0070: 1992

Synthesis Example 1

372 parts of aniline and 200 parts of toluene were fed into a flask equipped with a thermometer, a cooling tube, a Dean Stark azeotropic distillation trap and a stirrer, and 88 parts of 1,4-bischloromethylbenzene was added over 1 hour while maintaining the temperature at 60 to 70 ° C The reaction was carried out at the same temperature for 2 hours. Then, 104 parts of 35% hydrochloric acid was added dropwise over 1 hour while maintaining the temperature at 60 to 70 캜. After completion of the dropwise addition, water and toluene were distilled off while raising the temperature, and the system was adjusted to 205 to 210 캜 and reacted at this temperature for 10 hours. Thereafter, 277 parts of a 30% aqueous solution of sodium hydroxide was slowly added dropwise so that the system did not vigorously reflux while cooling. Toluene distilled off at 80 ° C or lower was returned to the system and allowed to stand at 70 ° C to 80 ° C. The separated aqueous layer of the lower layer was removed, and the reaction solution was washed with water until the washing liquid became neutral. Subsequently, excessive aniline and toluene were distilled off from the oil layer by heating under reduced pressure (200 DEG C, 0.6 KPa) with a rotary evaporator to obtain 138 parts of an aromatic amine resin (a1). The content of diphenylamine in the aromatic amine resin (a1) was 2.0%.

The resin thus obtained was again added dropwise with a small amount of water instead of blowing water vapor under reduced pressure (200 DEG C, 4 KPa) with a rotary evaporator. As a result, 131 parts of the aromatic amine resin (A1) was obtained. The obtained aromatic amine resin (A1) was in the form of a liquid having a high viscosity at room temperature, an amine equivalent of 150 g / eq and a diphenylamine content of 0.1% or less.

Synthesis Example 2

372 parts of aniline and 200 parts of toluene were fed into a flask equipped with a thermometer, a cooling tube, a Dean Stark azeotropic distillation trap and a stirrer, and 125 parts of 4,4'-bis (chloromethyl) biphenyl was kept at 60 to 70 ° C for 1 hour And the reaction was carried out at the same temperature for 2 hours. Then, 104 parts of 35% hydrochloric acid was added dropwise over 1 hour while maintaining the temperature at 60 to 70 캜. After completion of the dropwise addition, water and toluene were distilled off while raising the temperature, and the system was adjusted to 205 to 210 캜 and reacted at this temperature for 10 hours. Thereafter, 277 parts of a 30% aqueous solution of sodium hydroxide was slowly added dropwise so that the system did not vigorously reflux while cooling. Toluene distilled off at 80 ° C or lower was returned to the system and allowed to stand at 70 ° C to 80 ° C. The separated aqueous layer of the lower layer was removed, and the reaction solution was washed with water until the washing liquid became neutral. Subsequently, excessive aniline and toluene were distilled off from the oil layer in a reduced pressure state (200 DEG C, 0.6 KPa) with a rotary evaporator to obtain 173 parts of an aromatic amine resin (a2). The content of diphenylamine in the aromatic amine resin (a2) was 2.0%.

The resin thus obtained was again dropped in a rotary evaporator at a reduced pressure (200 DEG C, 4 KPa) in stead of blowing water vapor. As a result, 166 parts of the aromatic amine resin (A2) was obtained. The obtained aromatic amine resin (A2) had a softening point of 56 ° C, a melt viscosity of 0.035 Pa · s, an amine equivalent of 195 g / eq, and a diphenylamine content of 0.1% or less.

Example 1

147 parts of maleic anhydride, 200 parts of toluene and 4 parts of methanesulfonic acid were added to a flask equipped with a thermometer, a cooling tube, a Dean Stark azimetric distillation trap and a stirrer, and the mixture was heated to reflux. Next, a resin solution obtained by dissolving 150 parts of the aromatic amine resin (A1) in 95 parts of N-methyl-2-pyrrolidone and 95 parts of toluene was added dropwise over 3 hours while maintaining the reflux state. During this period, the condensed water azeotropic in reflux condition and the toluene were cooled and separated in a distillation trap of the Dean Stark. Then, the organic toluene was returned to the system, and the water was discharged to the outside of the system. After the completion of the dropwise addition of the resin solution, the reflux state was maintained and the reaction was carried out for 2 hours while the dehydration operation was carried out.

After completion of the reaction, washing with water was repeated 4 times to remove methanesulfonic acid and excess maleic anhydride, and water was removed from the system by azeotropic distillation of toluene and water under heating and decompression at 70 占 폚 or lower. Subsequently, 2 parts of methanesulfonic acid was added and the reaction was carried out for 2 hours under reflux. After the completion of the reaction, washing with water was repeated four times until the number of water wash became neutral, water was removed from the system by azeotropic distillation of toluene and water under heating and decompression at 70 DEG C or lower, and then toluene was completely distilled off, To obtain a maleimide resin (M1). The maleimide resin thus obtained had a softening point of 94 ° C, a melt viscosity of 4 Pa · s, and an acid value of 1.9 mg KOH / g.

Example 2

147 parts of maleic anhydride, 200 parts of toluene and 4 parts of methanesulfonic acid were added to a flask equipped with a thermometer, a cooling tube, a Dean Stark azimetric distillation trap and a stirrer, and the mixture was heated to reflux. Subsequently, a resin solution obtained by dissolving 195 parts of the aromatic amine resin (A2) in 95 parts of N-methyl-2-pyrrolidone and 95 parts of toluene was added dropwise over 3 hours while maintaining the reflux state. During this period, the condensed water azeotropic in reflux condition and the toluene were cooled and separated in a distillation trap of the Dean Stark. Then, the organic toluene was returned to the system, and the water was discharged to the outside of the system. After the completion of the dropwise addition of the resin solution, the reflux state was maintained and the reaction was carried out for 2 hours while the dehydration operation was carried out.

After completion of the reaction, washing with water was repeated 4 times to remove methanesulfonic acid and excess maleic anhydride, and water was removed from the system by azeotropic distillation of toluene and water under heating and decompression at 70 占 폚 or lower. Subsequently, 2 parts of methanesulfonic acid was added and the reaction was carried out for 2 hours under reflux. After the completion of the reaction, washing with water was repeated four times until the number of water wash became neutral, water was removed from the system by azeotropic distillation of toluene and water under heating and decompression at 70 DEG C or lower, and then toluene was completely distilled off, To obtain a maleimide resin (M2). The maleimide resin thus obtained had a softening point of 109 占 폚, a melt viscosity of 5 Pa 占 퐏, and an acid value of 1.6 mgKOH / g.

Comparative Example 1

400 parts of toluene and 100 parts of N-methyl-2-pyrrolidone were added to a flask equipped with a thermometer, a cooling tube, a Dean Stark air distillation trap and a stirrer, and 150 parts of the aromatic amine resin (A1) was added and dissolved. Then, 147 parts of maleic anhydride was added portionwise over 1 hour while maintaining the temperature at 50 to 60 占 폚. Thereafter, the reaction was carried out at 80 DEG C for 2 hours, 2 parts of methanesulfonic acid was added, and the reaction was carried out at 110 to 120 DEG C for 14 hours. During this period, the condensed water azeotropic in reflux condition and the toluene were cooled and separated in a distillation trap of the Dean Stark. Then, the organic toluene was returned to the system, and the water was discharged to the outside of the system. After completion of the reaction, washing with water was repeated 7 times, and toluene was completely distilled off under heating and reduced pressure to obtain a comparative maleimide resin (C1). The maleimide resin thus obtained had a softening point of 95 캜, a melt viscosity of 5 Pa s, and an acid value of 8.1 mgKOH / g.

Comparative Example 2

400 parts of toluene and 100 parts of N-methyl-2-pyrrolidone were added to a flask equipped with a thermometer, a cooling tube, a Dean Stark azimetric distillation trap and a stirrer, and 195 parts of an aromatic amine resin (A1) was added and dissolved. Then, 147 parts of maleic anhydride was added portionwise over 1 hour while maintaining the temperature at 50 to 60 占 폚. Thereafter, the reaction was carried out at 80 DEG C for 2 hours, 2 parts of methanesulfonic acid was added, and the reaction was carried out at 110 to 120 DEG C for 14 hours. During this period, the condensed water azeotropic in reflux condition and the toluene were cooled and separated in a distillation trap of the Dean Stark. Then, the organic toluene was returned to the system, and the water was discharged to the outside of the system. After completion of the reaction, washing with water was repeated seven times, and toluene was completely distilled off under heating and reduced pressure to obtain a comparative maleimide resin (C2). The maleimide resin thus obtained had a softening point of 119 占 폚, a melt viscosity of 6 Pa 占 퐏, and an acid value of 6 mgKOH / g.

Examples 3 to 4 and Comparative Examples 3 to 4

Various types of epoxy resins, curing agents and curing accelerators were used in the proportions shown in Table 1 (Table 1) using the maleimide resins (M1), (M2), (C1) and (C2) obtained in Examples 1 and 2 and Comparative Examples 1 and 2 The mixture was kneaded with a mixing roll and made into tablets, and then a resin molding was prepared by transfer molding and cured at 200 ° C for 2 hours. The physical properties of the cured product thus obtained were measured for the following items.

Glass Transition Temperature: The temperature measured by a dynamic viscoelasticity tester when tan δ is the maximum value.

Td5 (5% thermogravimetric reduction temperature): The obtained cured product was pulverized to obtain a powdery form, and the pyrolysis temperature was measured by TG-DTA using a sample of 100 mesh-pass and 200 mesh-on. A temperature at which the weight decreased by 5% as measured at a sample rate of 10 mg, a heating rate of 10 ° C / min, and an air quantity of 200 ml / hr.

· Flame resistance test: Measure the total residual flame time using a sample size of 12.5 mm in width, 150 mm in length and 0.8 mm in thickness.

Flexural strength: Measured in accordance with JIS K-6911.

· Moisture absorption rate: Weight increase rate after 24 hours at 85 ° C / 85% and 121 ° C / 100%. The test piece is a disk having a diameter of 50 mm and a thickness of 4 mm.

Curing shrinkage: Measured according to JIS K-6911.

week)

E1: NC-3000-L (epoxy equivalent weight 270 g / eq, manufactured by Nippon Kayaku Co., Ltd.)

P1: KAYAHARD GPH-65 (product of Nippon Kayaku Co., hydroxyl equivalent 200 g / eq)

2E4MZ: 2-ethyl-4-methylimidazole (available from Tokyo Chemical Industry Co., Ltd.)

It can be seen from Table 1 that the cured product of the maleimide resin of the present invention is superior in heat resistance and strength to a cured product of a maleimide resin having a high acid value and has low hygroscopicity. Since Td5 is high, the thermal decomposition temperature is high, and therefore, the flame retardancy is excellent. Further, since the shrinkage rate is small, when the laminate is used for a laminate or a carbon fiber composite material, the dimensional change due to molding is small, and a molded article according to the designed dimension can be easily produced.

Although the present invention has been described in detail with reference to specific embodiments thereof, it is apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

The present application is based on Japanese Patent Application (Japanese Patent Application No. 2016-065226) filed on March 29, 2016, which is incorporated by reference in its entirety. Also, all references cited herein are incorporated by reference in their entirety.

Claims (7)

A maleimide resin having an acid value of 5 mgKOH / g or less represented by the following formula (1).

Wherein X represents an aromatic hydrocarbon group having 6 to 18 carbon atoms. The plurality of R _{1 s} present each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aromatic group. m represents an integer of 1 to 4, and n represents a real number of 1 to 10.] The method according to claim 1,
A maleimide resin represented by the following formula (2).

Wherein the plurality of R _{1 s} present each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aromatic group; m represents an integer of 1 to 4, and n represents a real number of 1 to 10.] The method according to claim 1,
A maleimide resin represented by the following formula (3).

Wherein the plurality of R _{1 s} present each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aromatic group; m represents an integer of 1 to 4, and n represents a real number of 1 to 10.] 4. The method according to any one of claims 1 to 3,
An aromatic amine resin is reacted with maleic acid or maleic anhydride to produce an amide acid, and then a dehydration reaction is carried out in the presence of a catalyst. After removing excess maleic acid or maleic anhydride by washing with water, dehydration cyclization reaction Maleimide resin. A curable resin composition containing the maleimide resin according to any one of claims 1 to 4. A cured product obtained by curing the curable resin composition according to claim 5. An aromatic amine resin is reacted with maleic acid or maleic anhydride to produce an amide acid, and then a dehydration reaction is carried out in the presence of a catalyst. After removing excess maleic acid or maleic anhydride by washing with water, dehydration cyclization reaction (1). &Lt; / RTI &gt;

Wherein X represents an aromatic hydrocarbon group having 6 to 18 carbon atoms. The plurality of R _{1 s} present each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aromatic group. m represents an integer of 1 to 4, and n represents a real number of 1 to 10.]