JP6863830B2 - Resin composition, resin varnish, manufacturing method of laminated board, thermosetting molding material and sealing material - Google Patents

Description

The present invention relates to a resin composition, a resin varnish, a method for producing a laminated board, a thermosetting molding material, and a sealing material.

The thermosetting resin composition utilizes its curability and is used in various fields as a resin varnish, a thermosetting molding material, and the like. For example, in electronic components, copper-clad laminates obtained by laminating and curing a prepreg impregnated with a resin varnish on a fibrous base material and copper foil, a sealing material made of a cured product of a thermosetting molding material, and the like are used. Can be mentioned.

As a thermosetting resin composition, a maleimide resin has been attempted because it has a higher glass transition temperature and is excellent in heat resistance as compared with an epoxy resin. However, the cured product of the maleimide resin has a high elastic modulus and is hard and brittle, so that there is a drawback that the reliability of the electronic component is lowered.
Therefore, a resin composition containing an allylphenol resin and bismaleimides has been proposed as a means for improving the drawback that the cured product is hard and brittle (Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 6-132426 JP-A-2015-117375

However, it cannot be said that the cured product of the resin compositions of Patent Documents 1 and 2 has sufficiently improved the drawback of being hard and brittle. In order to obtain highly reliable electronic components, it is important to further improve the flexibility and toughness of the cured product.

The present invention relates to a resin composition capable of forming a cured product having excellent flexibility and toughness while ensuring sufficient heat resistance, a resin varnish using the resin composition, a method for producing a laminated board, and a thermosetting molding. It is an object of the present invention to provide a material and a sealing material.

The present invention has the following aspects.
[1] A liquid polyvalent hydroxy resin and a maleimide compound having two or more maleimide groups in one molecule are contained.
The liquid multivalent hydroxy resin has a structural unit represented by the following formula (u1) and a structural unit represented by the following formula (u2), and contains a compound represented by the following formula (m2). ,
The ratio of the total mass of the structural unit represented by the formula (u2) and the compound represented by the formula (m2) to the total mass of the liquid polyvalent hydroxy resin is 70 to 90% by mass.
A resin composition having a mass average molecular weight of the liquid polyvalent hydroxy resin of 800 to 1600.

[In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is a linear or branched hydrocarbon group having 10 to 25 carbon atoms including an unsaturated group, and X is a hydrogen atom or a hydroxyl group. m and n are independently 0 or 1, respectively, and Y is a hydrogen atom or a methyl group. ]
[2] The total molar ratio (maleimide group / unsaturated group) of the maleimide groups of the maleimide compound to the total of unsaturated groups of the liquid polyvalent hydroxy resin is 0.5 to 3.0. 1] The resin composition according to.
[3] The resin composition according to [1] or [2], further comprising an epoxy resin.
[4] The resin composition according to any one of [1] to [3], further comprising a curing accelerator that promotes a curing reaction between the liquid polyvalent hydroxy resin and the maleimide compound, and an inorganic filler.
[5] The resin composition according to any one of [1] to [4], further comprising a solvent.
[6] A resin varnish comprising the resin composition according to [5].
[7] A method for producing a laminated board, wherein a laminated board containing a prepreg impregnated with the resin varnish according to [6] in a fibrous base material is heated and pressed and cured to obtain a laminated board.
[8] A thermosetting molding material comprising the resin composition according to [4].
[9] A sealing material made of a cured product of the thermosetting molding material according to [8].

According to the present invention, a cured product having excellent flexibility and toughness can be formed, and a laminated plate or a sealing material having excellent reliability can be obtained.

<Resin composition>
The resin composition of the present invention contains a liquid polyvalent hydroxy resin and a maleimide compound having two or more maleimide groups in one molecule (hereinafter, also referred to as maleimide compound (I)).

[Liquid multivalent hydroxy resin]
The liquid multivalent hydroxy resin has a structural unit represented by the following formula (u1) (hereinafter, also referred to as a structural unit (u1)) and a structural unit represented by the following formula (u2) (hereinafter, the structural unit (u2)). ), And includes a compound represented by the following formula (m2) (hereinafter, also referred to as compound (m2)). That is, the liquid polyvalent hydroxy resin is a raw material (phenols, etc.) such as a polymer having a constituent unit (u1) and a constituent unit (u2) and a compound (m2) which is a non-polymer used for producing the polymer. It is a composition containing.
The "constituent unit" indicates a unit that constitutes the polymer.

The liquid polyhydric hydroxy resin is typically polycondensed with formaldehyde from one or both of phenol and methylphenol (a compound represented by the formula (m1) described later) and phenols containing the compound (m2). It is a thing. The compound (m2) has a high boiling point and cannot be removed by distillation and tends to remain in the liquid multivalent hydroxy resin.

[In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is a linear or branched hydrocarbon group having 10 to 25 carbon atoms including an unsaturated group, and X is a hydrogen atom or a hydroxyl group. m and n are independently 0 or 1, respectively, and Y is a hydrogen atom or a methyl group. ]

"-*" Indicates a bond. At least one of the three bonds in the formula (u1) is combined with another structural unit (another structural unit (u1), a structural unit (u2), etc.), and the three bonds in the formula (u2). At least one of them is combined with another structural unit (another structural unit (u2), a structural unit (u1), etc.). Of the bonds in each equation, the bonds that do not bind to other constituent units bind to the hydrogen atom.
However, the benzene ring in the structural unit (u1) and the benzene ring in the structural unit (u2) are bonded via a methylene group and are not directly bonded. Further, when two or more structural units (u1) are contained in the same molecule and the structural units (u1) are directly bonded to each other, the benzene rings in each structural unit (u1) are bonded via a methylene group. , Do not combine directly. Similarly, when there are two or more structural units (u2) in the same molecule and the structural units (u2) are directly bonded to each other, the benzene ring in each structural unit (u2) is bonded via a methylene group. And do not join directly.

That is, the bond extending from the benzene ring in the formula (u1) is bonded to another structural unit or a hydrogen atom. When bound to another structural unit, the bond is attached to the methylene group of the other structural unit (another structural unit (u1), a structural unit (u2) in which at least one of m and n is 1, etc.). To do.
The bond extending from the methylene group in the formula (u1) is bonded to the benzene ring of another structural unit (constituent unit (u2), another structural unit (u1), etc.).

The bond extending from the benzene ring in formula (u2) binds to another building block or to a hydrogen atom. When bound to another structural unit, the bond is attached to the methylene group of the other structural unit (such as the structural unit (u1), another structural unit (u2) in which at least one of m and n is 1). To do.
When m in the formula (u2) is 0 (or n is 0), − (CH ₂ ) _m − * (or − (CH ₂ ) _n − *) is the same as the bond extending from the benzene ring. Indicates a bond (-*). That is, it binds to other building blocks or to a hydrogen atom. When bonded to another structural unit, the bond is bonded to the methylene group of the other structural unit in the same manner as the bond extending from the benzene ring.
When m in formula (u2) is 1 (or n is 1), − (CH ₂ ) _m − * (or − (CH ₂ ) _n − *) is a methylene group, and its bond is other. (Constituent unit (u1), another structural unit (u2)) is bonded to the benzene ring of the above, or is bonded to a hydrogen atom to form a methyl group. However, when both m and n are 1, _{at least one of − (CH 2} ) _m − * and − (CH ₂ ) _n − * is bonded to the benzene ring of the other constituent unit. That is, two methyl groups are not bonded to the benzene ring in the formula (u2).

In formula (u1), R ¹ is a hydrogen atom or a methyl group. By having the structural unit (u1), it is easy to obtain a cured product having good heat resistance.
When R ¹ is a methyl group, in the formula (u1), ^{the bond position of R 1 on} the benzene ring is the position where the hydroxyl group is bonded (position 1) in that it is inexpensive and the synthesized resin is easily liquefied. ), The ortho position (2nd or 6th position) is preferable.
The single bond and the bond position of the methylene group on the benzene ring are not particularly limited. Typically, it is either the ortho position (2nd or 6th position) or the para position (4th position) with respect to the position (1st position) where the hydroxyl group is bonded.

The structural unit (u1) may ^{consist only of a structural unit in which R 1} is a methyl group (hereinafter, also referred to as a cresol unit) ^{, and a structural unit in which R 1} is a hydrogen atom (hereinafter, also referred to as a phenol unit). It may be composed of only cresol units and phenol units.
The higher the ratio of the cresol unit in the structural unit (u1), the lower the viscosity of the liquid polyvalent hydroxy resin, the longer the gelation time, the lower the elastic modulus of the cured product, and the lower the glass transition temperature. Conversely, the higher the proportion of phenol units, the higher the viscosity of the liquid polyvalent hydroxy resin, the shorter the gelation time, the higher the elastic modulus of the cured product, and the higher the glass transition temperature. The ratio of the cresol unit to the phenol unit can be appropriately set in consideration of these characteristics.
From the viewpoint of low viscosity and low elastic modulus, the structural unit (u1) preferably contains at least a cresol unit.
The content of the cresol unit is preferably 0 to 100% by mass, more preferably 30 to 100% by mass, based on the total amount (100% by mass) of the constituent unit (u1).
Therefore, the content of the phenol unit is preferably 0 to 100% by mass, more preferably 0 to 70% by mass, based on the total amount of the constituent unit (u1).
Alternatively, the content of the phenol unit is preferably 10% by mass or less with respect to the constituent unit (u2).

In formula (u2), R ² is a linear or branched hydrocarbon group having 10 to 25 carbon atoms containing an unsaturated group. When the number of carbon atoms is 10 or more, the viscosity of the liquid multivalent hydroxy resin at room temperature can be easily lowered, and a cured product having a low elastic modulus and high toughness can be obtained. Since the number of carbon atoms is 25 or less, the heat resistance of the cured product is good.
The hydrocarbon group preferably has 10 to 25 carbon atoms, more preferably 15 to 20 carbon atoms.
Examples of the unsaturated group include a vinyl group and a vinylene group. The unsaturated group contained in the hydrocarbon group may be one or two or more.
Examples of the hydrocarbon group include unsaturated hydrocarbon groups having a carbon-carbon double bond. Specifically, − (CH ₂ ) ₇ CH = CH (CH ₂ ) ₅ CH ₃ , − (CH _2). ) ₇ CH = CHCH ₂ CH = CH (CH ₂ ) ₂ CH ₃ ,-(CH ₂ ) ₇ CH = CHCH ₂ CH = CHCH = CHCH ₃ ,-(CH ₂ ) ₇ CH = CHCH ₂ CH = CHCH ₂ CH = CH _{2 and the} like can be mentioned.
In the formula (u2), X is preferably a hydrogen atom in that the water absorption of the cured product is low.

Wherein (u2), the bonding position of R ² is in the benzene ring, from the viewpoint of reactivity with formaldehyde, bonded position of the hydroxyl group (position 1) to the meta-position (3-position or 5-position) are preferred. When X is a hydroxyl group, the 1-position does not indicate the bond position of X, but the bond position of the hydroxyl group represented as "OH" in the formula.
The bond positions of X and Y on the benzene ring are not particularly limited. When X is a hydroxyl group, the meta position is preferable with respect to the position (1st position) where the hydroxyl group is bonded, which is represented as "OH" in the formula, in terms of reactivity with formaldehyde. When Y is a methyl group, the ortho position is preferable with respect to the position (1 position) where the hydroxyl group is bonded.
The single bond, − (CH ₂ ) _m − * and − (CH ₂ ) _n − * bond positions on the benzene ring are not particularly limited. Typically, it is either the ortho position (2nd or 6th position) or the para position (4th position) with respect to the position (1st position) where the hydroxyl group is bonded.

In addition to the structural unit (u1) and the structural unit (u2), the polymer contained in the liquid multivalent hydroxy resin is a structural unit other than the structural unit (u1) and the structural unit (u2) (hereinafter, the structural unit (u3)). It may also have).
Examples of the structural unit (u3) include a structural unit represented by the following formula (u31) (hereinafter, also referred to as a structural unit (u31)).

[In the formula, R ³ is an allyl group. ]

The bond extending from the benzene ring in the formula (u31) is bonded to another structural unit or a hydrogen atom in the same manner as the bond extending from the benzene ring in the formula (u1). When bound to another building block, the bond binds to the methylene group of the other building block. Further, the bond extending from the methylene group is bonded to the benzene ring of another constituent unit.

The ratio of the total mass of the constituent unit (u2) and the compound (m2) to the total mass of the liquid polyvalent hydroxy resin is 70 to 90% by mass, and 70 to 85% by mass is particularly preferable.
Both the structural unit (u2) and the compound (m2) have R ² . If the ratio of the structural unit (u2) and the compound (m2) is equal to or higher than the lower limit, the liquid polyvalent hydroxy is not introduced even if the allyl group is not introduced (for example, even if the structural unit (u31) is not present). The viscosity of the resin at room temperature is low. Moreover, a cured product having a low elastic modulus can be obtained. When the ratio of the structural unit (u2) and the compound (m2) is not more than the above upper limit value, the curability and heat resistance are good.
The ratio of the structural unit (u2) to the total of the structural unit (u2) and the compound (m2) is not particularly limited as long as the mass average molecular weight of the liquid polyvalent hydroxy resin is 800 to 1600.

The total ratio of the constituent units (u2) and the compound (m2) in the liquid polyvalent hydroxy resin is calculated from the amount of phenols used in the production of the liquid polyvalent hydroxy resin, nuclear magnetic resonance spectroscopy, etc. It can be confirmed by a known analysis method.
The total ratio of the constituent unit (u2) and the compound (m2) in the liquid polyvalent hydroxy resin is, for example, the ratio of formaldehyde to the compound (m2) when the liquid polyvalent hydroxy resin is produced by the production method (i) described later. It can be adjusted according to the ratio, reaction conditions (catalyst amount / species, temperature, time), etc.

The liquid polyhydric hydroxy resin is excellent in terms of the environment, has a high curing rate with the maleimide compound (I), and has heat resistance. Therefore, a polymer or compound having a structural unit (u1) and a structural unit (u2) ( It is preferable that it does not contain phenols and formaldehyde other than m2).
Further, the balance obtained by removing the constituent unit (u2) and the compound (m2) from the liquid polyvalent hydroxy resin is preferably the constituent unit (u1) or is preferably composed of the constituent unit (u1) and the constituent unit (u3). , It is particularly preferable that it is a structural unit (u1).

The content of the structural unit (u3) in the liquid polyvalent hydroxy resin is preferably 10% by mass or less, particularly preferably 0% by mass, based on the structural unit (u2) from the viewpoint of lowering the elastic modulus of the cured product. That is, it is particularly preferable that the liquid multivalent hydroxy resin does not have a constituent unit (u3).
The content of the structural unit (u31) in the liquid polyvalent hydroxy resin is preferably 10% by mass or less, particularly preferably 0% by mass, based on the structural unit (u2) from the viewpoint of lowering the elastic modulus of the cured product. That is, it is particularly preferable that the liquid multivalent hydroxy resin does not have a constituent unit (u31).

The mass average molecular weight (Mw) of the liquid multivalent hydroxy resin is 800 to 1600, preferably 900 to 1600, and more preferably 1000 to 1600. The smaller the Mw, the lower the viscosity of the liquid multivalent hydroxy resin at 25 ° C. When Mw is not more than the above upper limit value, the liquid multivalent hydroxy resin exhibits excellent fluidity at room temperature. When Mw is at least the above lower limit value, the reactivity with the maleimide compound (I) is excellent, and the heat resistance of the cured product is good.
The dispersity (Mw / number average molecular weight (Mn)) of the liquid multivalent hydroxy resin is preferably 1.4 to 1.6.
Mw and Mn are values measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

The viscosity of the liquid polyvalent hydroxy resin at 25 ° C. is preferably 100 Pa · s or less, more preferably 50 Pa · s or less, and particularly preferably 30 Pa · s or less. When the viscosity at 25 ° C. is not more than the upper limit value, the fluidity is excellent. The lower the viscosity of the liquid polyvalent hydroxy resin at 25 ° C. is, the more preferable it is, and the lower limit of the viscosity is not particularly limited.
The viscosity of the liquid polyvalent hydroxy resin at 25 ° C. is measured by an E-type (cone plate type) viscometer.
The viscosity of the liquid polyvalent hydroxy resin can be adjusted by the ratio of the total mass of the liquid polyvalent hydroxy resin Mw, the structural unit (u2) and the compound (m2).

The liquid multivalent hydroxy resin can be produced by reacting a compound represented by the following formula (m1) (hereinafter, also referred to as compound (m1)) with the compound (m2) and formaldehyde. When the compound (m1), the compound (m2) and the formaldehyde are reacted, the addition reaction of formaldehyde (methylation reaction) to the compound (m1) or the compound (m2) and the produced methylol form and the compound (m1) or the compound ( The condensation reaction with m2) proceeds. As a result, a liquid multivalent hydroxy resin is produced.
Compounds (m1), (m2) and formaldehyde may be reacted with other phenols other than compound (m1) and compound (m2).

[In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is a linear or branched hydrocarbon group having 10 to 25 carbon atoms including an unsaturated group, and X is a hydrogen atom or a hydroxyl group. Y is a hydrogen atom or a methyl group. ]

^{R 1} in the formula (m1) is the same ^{as R 1} in the formula (u1).
The compound (m1) used in the reaction may consist of a single compound or a mixture of two or more kinds, for example, phenol, orthocresol (2-methylphenol), metacresol (3-methylphenol), paracresol (4). -Methylphenol) and the like.
As the compound (m1), phenol, orthocresol or a mixture thereof is preferable, and orthocresol or a mixture of orthocresol and phenol is particularly preferable, because it is inexpensive and the synthesized resin is easily liquefied.

Each ^R 2, X in the formula (m2) is the same as ^R 2, X in formula (u2).
The compound (m2) used in the reaction may consist of a single compound or a mixture of two or more kinds, for example, cashew nut shell liquid and its purified product, cardanol, cardol (also referred to as curdall), 2-methylcardol. , Anacardic acid, urushiol and the like.
As the compound (m2), it is relatively inexpensive, its reactivity can be easily controlled, the obtained resin tends to be in a liquid state, and a cured product having a low elastic modulus can be easily obtained. Therefore, cashew nut shell liquid or its purification The thing is preferable. Cashew nut shell liquid often contains a plurality of compounds (m2) containing cardanol.
The cashew nut shell liquid or its refined product contains 70 to 100% by mass of cardanol, 0 to 25% by mass of cardol, and methyl cardanol based on the total mass of cashew nut shell liquid or its refined product. The content of the above is 0 to 5% by mass, and the total amount (active ingredient amount) of cardanol, cardol and methyl cardanol is preferably 70% by mass or more.

Examples of other phenols include allylphenol and the like. When allylphenol is used as another phenol, a liquid polyvalent hydroxy resin having a constituent unit (u31) can be obtained.

As a method for producing the liquid multivalent hydroxy resin, the following production method (i) is preferable.
Production method (i): Compound (m2) and formaldehyde, or compound (m1), compound (m2) and formaldehyde are reacted in the presence of a basic catalyst, and the reaction product and compound (m1) are combined. Is reacted in the presence of an acidic catalyst to obtain a liquid polyvalent hydroxy resin.

Of the compound (m1) and the compound (m2), the compound (m2) has lower reactivity with formaldehyde. Therefore, when these are collectively reacted with formaldehyde, the unreacted compound (m2) tends to remain in the reaction product. If the compound (m2) remains in the liquid multivalent hydroxy resin, the cured physical properties are deteriorated. Further, since the compound (m2) has a high boiling point, the residual compound (m2) cannot be easily removed.
Therefore, first, the compound (m2) is reacted before the compound (m1) is reacted (reacted in the absence of the compound (m1)), or of the total amount used for producing the liquid polyvalent hydroxy resin. The compound (m2) is reacted in the presence of some compounds (m1).
When the compound (m2) and formaldehyde are reacted in the presence of a basic catalyst, 1 to 3 molecules of formaldehyde are added to the compound (m2) to form a methylol compound represented by the following formula (3). When compound (m1), compound (m2) and formaldehyde are reacted in the presence of a basic catalyst, 1 to 3 molecules of formaldehyde are added to each of compound (m1) and compound (m2), and the following formula (4) A methylol compound represented by the above formula (3) is produced.
By adding the compound (m1) to the methylol compound thus produced, it is possible to prevent the compound (m2) from remaining in the liquid polyvalent hydroxy resin.

[In the equation, R ¹ , R ² , X and Y are the same as described above, k is an integer of 1 to 3, and h is an integer of 1 to 3. ]

The reaction between the reaction product and the compound (m1) proceeds even in the presence of a basic catalyst, but in the presence of a basic catalyst, the methylols produced in the first-stage reaction react with each other to form a constituent unit (a constituent unit ( Side reactions such as a reaction in which a structure composed of only u2) is generated and a reaction in which a methylol compound is produced to formaldehyde are likely to cause a side reaction such as a reaction in which a methylol compound is produced, and the mass average molecular weight tends to increase. ..
On the other hand, in the presence of an acidic catalyst, the reaction between the methylol compound produced in the first-stage reaction and the excess compound (m1) tends to proceed preferentially, and the formaldehyde produced by the reaction of the methylol compound is excessive. It reacts preferentially with the compound (m1) in the above, and the above-mentioned side reaction is unlikely to occur. Therefore, it is easy to obtain a liquid multivalent hydroxy resin in which the mass average molecular weight is controlled to be equal to or lower than the upper limit value.

Hereinafter, the case of producing the liquid multivalent hydroxy resin by the production method (i) will be described in detail.
In the production method (i), first, the first-stage reaction is carried out in which the compound (m2) and formaldehyde are reacted, or the compound (m1), the compound (m2) and formaldehyde are reacted in the presence of a basic catalyst.
The total amount of compound (m2), which is usually used in the production of a liquid multivalent hydroxy resin, is used in the first-stage reaction.
The amount of the compound (m1) used in the first-stage reaction is preferably 30% by mass or less, more preferably 10% by mass or less, based on the compound (m2). If it is not more than the upper limit value, the viscosity of the obtained multivalent hydroxy resin tends to be lower. The lower limit of this amount is not particularly limited and may be 0% by mass.
When the compound (m1) contains phenol, the phenol unit can be more reliably introduced into the structure of the liquid polyvalent hydroxy resin by using at least a part of the phenol in the first stage. However, when the ratio of phenol to the compound (m2) used in the first-stage reaction increases, the number of condensates having no constituent unit (u2) increases, and the amount of the compound (m2) remaining unreacted increases. As a result, the cured physical properties may deteriorate. Therefore, from the viewpoint of obtaining more excellent cured physical properties, the amount of phenol used in the first-stage reaction is preferably 10% by mass or less based on the total amount of the compound (m2).
As the formaldehyde, a solid formaldehyde or an aqueous solution may be used. It is preferable to use an aqueous solution because it is inexpensive and the reaction can be easily controlled.

The amount of formaldehyde to react in the presence of a basic catalyst, that is, the amount of formaldehyde to react with compound (m2), or compound (m1) and compound (m2) in the first stage reaction, is relative to compound (m2). It is preferably 10 to 80% by mass, more preferably 20 to 60% by mass.
The molar ratio of formaldehyde to the compound (m2) (formaldehyde / compound (m2)) is preferably 0.5 to 4.0, more preferably 1.0 to 3.0.
The smaller the amount of formaldehyde within the above range, the larger the total content of the structural unit (u2) and the compound (m2) in the liquid multivalent hydroxy resin tends to be. The higher the amount of formaldehyde in the above range, the smaller the ratio of the compound (m2) to the total content tends to be.
If the amount of formaldehyde is too small, a large amount of unreacted compound (m2) remains in the produced liquid polyvalent hydroxy resin, and the cured physical properties such as the glass transition temperature and the curing rate may decrease. If the amount of formaldehyde is too large, excess formaldehyde remains in the produced liquid multivalent hydroxy resin, and it is necessary to remove the excess formaldehyde, which leads to an increase in cost and is not preferable.
The cashew nut shell liquid may contain components other than the compound (m2). When cashew nut shell liquid is used, the amount of the active ingredient of cashew nut shell liquid (total amount of cardanol, cardol and methyl cardanol) is the amount of compound (m2).

The basic catalyst is not particularly limited as long as the reaction proceeds. For example, alkali metal hydroxides (sodium hydroxide, potassium hydroxide, etc.), aqueous ammonia, tertiary amines (triethylamine, etc.), alkali earth metal oxides and hydroxides such as calcium, magnesium, and barium, and sodium carbonate. Alkaline substances such as. One type of basic catalyst may be used alone, or two or more types may be used in combination.

In the first-stage reaction, the amount of the basic catalyst used is 1.3 to 1.3 to the total of the compound (m1) and the compound (m2) (only the compound (m2) when the compound (m1) is not reacted). 40% by mass is preferable, and 6.7 to 20% by mass is more preferable.
The molar ratio of the basic catalyst to the sum of the compound (m1) and the compound (m2) (only the compound (m2) when the compound (m1) is not reacted) (basic catalyst / {compound (m1) + compound ( m2)}) is preferably 0.1 to 3.0, more preferably 0.5 to 1.5.
If the amount of the basic catalyst used is too small, the reaction rate will be slow, and if the amount used is too large, the reaction will proceed rapidly and it will be difficult to control the reaction.

The first-stage reaction is preferably carried out in the presence of an alcohol having 1 to 4 carbon atoms such as methanol, ethanol, propanol and butanol. This makes it possible to prevent the compound (m2) and the reaction product from agglutinating during the first-stage reaction.
Alcohols having 1 to 4 carbon atoms may be used alone or in combination of two or more. As the alcohol having 1 to 4 carbon atoms, methanol is particularly preferable.
The amount of the alcohol having 1 to 4 carbon atoms is preferably 10 to 100% by mass with respect to the total of the compound (m1) and the compound (m2) (only the compound (m2) when the compound (m1) is not reacted). ..
In the subsequent reaction with the compound (m1) under an acidic catalyst (second-stage reaction), the alcohol having 1 to 4 carbon atoms remaining in the reaction system also functions as an alkylating agent. _{The methylol group (-CH 2} OH) of the compound (m2) (methylol product of the formula (3)) converted to methylol in the first-stage reaction is an alkyl group of an alcohol having 1 to 4 carbon atoms (hereinafter, abbreviated as R). .) capped, and _-CH 2 O-R (capped methylol body). As a result, as compared with the case where the methylol group exists as it is, a side reaction in which the methylol compounds of the compound (m2) react with each other during the second-stage reaction is less likely to occur.
On the other hand, the methylol form and the capped methylol form easily react with the compound (m1) present in excess, so that the target resin can be easily obtained.

The reaction temperature in the first-stage reaction is preferably 0 to 100 ° C, more preferably 30 to 60 ° C. If the reaction temperature is too low, the reaction will not proceed, and if it is too high, it will be difficult to control the reaction, and it will be difficult to stably obtain the desired liquid multivalent hydroxy resin.
At the end of the first-stage reaction, an acid may be added to the reaction product obtained in the first-stage reaction to neutralize the basic catalyst.

Next, the second-stage reaction is carried out in which the reaction product obtained in the first-stage reaction and the compound (m1) are reacted in the presence of an acidic catalyst.

The total amount of the compound (m1) to be reacted in the presence of the basic catalyst and the amount to be reacted in the presence of the acidic catalyst, that is, the amount of the compound (m1) used in the first-stage reaction and the second-stage reaction. The total amount of the compound (m1) and the amount of the compound (m1) used in the above is preferably 72 to 361% by mass, more preferably 108 to 324% by mass, based on the compound (m2) used in the first-stage reaction.
The total amount of the compound (m1) used in the first-stage reaction and the compound (m1) used in the second-stage reaction, and the molar ratio of the compound (m2) used in the first-stage reaction (m2). The compound (m1) / compound (m2)) is preferably 2.0 to 10.0, more preferably 3.0 to 9.0.
If the ratio of the compound (m1) is too low, the mass average molecular weight of the liquid polyvalent hydroxy resin becomes large, and the viscosity at room temperature becomes high. If the ratio of the compound (m1) is too high, the yield will decrease and the cost will increase.

Examples of the acidic catalyst include hydrochloric acid, sulfuric acid, phosphoric acid, oxalic acid, trifluoroacetic acid, p-toluenesulfonic acid, methanesulfonic acid, boron trifluoride, aluminum chloride, iron chloride, zinc chloride and the like. The acidic catalyst may be used alone or in combination of two or more.
Of the above, hydrochloric acid, sulfuric acid, oxalic acid, and p-toluenesulfonic acid are preferable because they can be obtained at a relatively low cost.

In the second-stage reaction, the amount of the acidic catalyst used is preferably 0.04 to 12.6% by mass, preferably 0.4 to 4.2% by mass, based on the compound (m2) used in the first-stage reaction. Is more preferable.
The molar ratio of the acidic catalyst to the compound (m2) (acid catalyst / compound (m2)) is preferably 0.001 to 0.3, more preferably 0.01 to 0.1.
If the amount of the acidic catalyst used is too small, the reaction rate will be slow, and if the amount used is too large, the reaction will proceed rapidly and it will be difficult to control the reaction.

The reaction temperature in the second stage reaction is preferably 30 to 150 ° C, more preferably 80 to 120 ° C. If the reaction temperature is too low, the reaction will not proceed, and if it is too high, it will be difficult to control the reaction, and it will be difficult to stably obtain the desired liquid multivalent hydroxy resin.

In the reaction product obtained by the second-stage reaction, if the total ratio of the constituent unit (u2) and the compound (m2) is 70 to 90% by mass and the mass average molecular weight is 800 to 1600, the present invention is used as it is. Can be a liquid polyvalent hydroxy resin.
After the second-stage reaction, if necessary, the reaction product may be subjected to treatments such as removal of unreacted raw materials by distillation and the like, concentration and purification (washing, column chromatography, etc.). Unreacted formaldehyde and compound (m1) are preferably removed by washing, distillation or the like. When other phenols are used, it is preferable to remove the other phenols as well.

In the production method (i), when other phenols are reacted with the compounds (m1), (m2) and formaldehyde, the timing of reacting the other phenols can be appropriately set according to the reactivity with formaldehyde. For example, it may be reacted at the time of the first-stage reaction, it may be reacted at the time of the second-stage reaction, or it may be reacted at both of them.
When the other phenols are allylphenols, allylphenols, like compound (m1), are more reactive with formaldehyde than compound (m2). Therefore, when the other phenols are allylphenols, it is preferable to react the compound (m2) with formaldehyde and then react with the reaction product. That is, it is preferable that the compound (m2) and formaldehyde are reacted in the presence of a basic catalyst, and the reaction product, the compound (m1) and other phenols are reacted in the presence of an acidic catalyst.

[Maleimide compound (I)]
The maleimide compound (I) is a maleimide compound having two or more maleimide groups in one molecule. Examples of the maleimide compound (I) include bismaleimides having two maleimide groups in one molecule, polyphenylmethane maleimide, and the like.

Examples of bismaleimides include alkyl bismaleimide, diphenylmethane bismaleimide, phenylene bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4 -Methyl-1,3-phenylene bismaleimide, 1,6'-bismaleimide- (2,2,4-trimethyl) hexane, 4,4'-diphenyl ether bismaleimide, 4,4'-diphenylsulphon bismaleimide, 1 , 3-Bis (3-maleimide phenoxy) benzene, 1,3-bis (4-maleimide phenoxy) benzene can be mentioned.
Polyphenylmethane maleimide is a polymer in which three or more benzene rings substituted with maleimide groups are bonded via a methylene group.

As the maleimide compound (I), 4,4'-diphenylmethanebismaleimide and polyphenylmethanemaleimide are preferable because of their excellent compatibility with the liquid polyvalent hydroxy resin and their relatively low cost.
As the maleimide compound (I), a commercially available product may be used. Specifically, for example, the product name "BMI-1100"(4,4'-diphenylmethanebismaleimide) and the product name "BMI-2300" (polyphenylmethanemaleimide) manufactured by Daiwa Kasei Kogyo Co., Ltd. can be mentioned.
As the maleimide compound (I), one type may be used alone, or two or more types may be used in combination.

^{In the resin composition of the present invention, curing proceeds by reacting the unsaturated group contained in R 2} in the constituent unit (u2) of the liquid polyvalent hydroxy resin with the maleimide group of the maleimide compound (I). As described above, in the present invention, the liquid polyvalent hydroxy resin functions as a curing agent for the maleimide compound (I).

The total molar ratio of maleimide groups (maleimide group / unsaturated group) of the maleimide compound (I) to the total unsaturated groups of the liquid polyvalent hydroxy resin in the resin composition is 0.5 to 3.0. Preferably, 0.8 to 2.0 is more preferable, and 0.9 to 1.5 is even more preferable. When the molar ratio is at least the lower limit value, the obtained cured product can be imparted with physical properties having good heat resistance and a low elastic modulus. When the molar ratio is not more than the upper limit value, the heat resistance is good.

[Other ingredients]
The resin composition of the present invention may contain other components other than the liquid polyvalent hydroxy resin and the maleimide compound (I) in addition to the liquid polyvalent hydroxy resin and the maleimide compound (I). Examples of other components include maleimide curing agents other than epoxy resins and liquid polyvalent hydroxy resins, curing accelerators, inorganic fillers, solvents, mold release agents, surface treatment agents, colorants, flexibility-imparting agents, and the like. Be done.

The resin composition of the present invention preferably contains an epoxy resin because it has excellent adhesion to the cured product and the curing reaction tends to proceed and the molecular weight of the cured product tends to increase. The curing reaction of the liquid polyvalent hydroxy resin and the epoxy resin proceeds by the reaction between the hydroxyl group of the liquid polyvalent hydroxy resin and the epoxy group of the epoxy resin.

The epoxy resin is not particularly limited, and for example, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenol type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy. Resins, naphthol type epoxy resins, xylylene type epoxy resins, biphenyl type epoxy resins, triphenylmethane type epoxy resins, dicyclopentadiene type epoxy resins, stillben type epoxy resins, sulfur atom-containing epoxy resins, phosphorus atom-containing epoxy resins, etc. Be done.

As the epoxy resin, an epoxy resin in which at least a part of the hydroxyl groups of the liquid polyvalent hydroxy resin is epoxidized may be used. The epoxidation of the hydroxyl group can be carried out by a known method. For example, by reacting a liquid polyvalent hydroxy resin with epichlorohydrin, a part or all of the hydroxyl groups of the liquid polyvalent hydroxy resin becomes -OZ (where Z is a glycidyl group). An epoxy resin can be obtained.
As the epoxy resin, any one type may be used alone, or two or more types may be used in combination.

The equivalent ratio (epoxy group / hydroxyl group) of the epoxy group equivalent of the epoxy resin to the hydroxyl group equivalent of the liquid polyvalent hydroxy resin in the resin composition is preferably 0.7 to 1.5, more preferably 0.9 to 1.1. preferable. When the equivalent ratio is within the above range, the obtained cured product has a lower elastic modulus.

Examples of other maleimide curing agents include novolac type resins such as allyl novolac type phenol resins.

Examples of the curing accelerator include a curing accelerator (hereinafter, also referred to as a curing accelerator (P)) that promotes the curing reaction between the liquid polyvalent hydroxy resin and the maleimide compound (I), and a curing accelerator (P) other than the curing accelerator (P). Examples thereof include a curing accelerator (hereinafter, also referred to as a curing accelerator (Q)) that promotes a curing reaction between a liquid polyvalent hydroxy resin and an epoxy resin.

Examples of the curing accelerator (P) include imidazoles and organic peroxides. When the resin composition contains an epoxy resin, if imidazoles are used as the curing accelerator (P), the curing reaction between the liquid polyvalent hydroxy resin and the epoxy resin is also promoted.

Examples of imidazoles include 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-ethylimidazole, 2,4-dimethylimidazole, 2-undecyl imidazole, 2-heptadecyl imidazole, 2-phenyl imidazole, and the like. 2-Phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 1-vinyl-2- Methylimidazole, 1-propyl-2-methylimidazole, 2-isopropylimidazole, 1-cyanomethyl-2-methyl-imidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-Cyanoethyl-2-phenylimidazole can be mentioned.

Examples of organic peroxides include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxydicarbonates, and peroxyesters.

The curing accelerator (P) is preferably relatively stable at high temperature, has good solvent solubility, and is easy to handle. For imidazoles, 2-ethyl-4-methylimidazole, and for organic peroxides, dialkyl. Dicumyl peroxide of peroxide is preferable.
As the curing accelerator (P), one type may be used alone, or two or more types may be used in combination.
The content of the curing accelerator (P) is preferably 0.1 to 5.0% by mass with respect to the maleimide compound (I).

The curing accelerator (Q) is not particularly limited, and examples thereof include phosphorus compounds, tertiary amines, organic acid metal salts, Lewis acids, and amine complex salts.
Examples of the phosphorus compound include triphenylphosphine, tris-2,6-dimethoxyphenylphosphine, tri-p-tolylphosphine, triphenyl phosphine and the like. Examples of the tertiary amine include 2-dimethylaminomethylphenol, benzyldimethylamine, α-methylbenzyldimethylamine, 1,8-diazabicyclo [5.4.0] undecene-7 and the like. Any one of these curing accelerators may be used alone, or two or more thereof may be used in combination.
As the curing accelerator (Q), a phosphorus compound (particularly triphenylphosphine) is preferable because it has more excellent curability, heat resistance, electrical characteristics, and moisture resistance reliability is unlikely to decrease.
The content of the curing accelerator (Q) is preferably 0.1 to 5% by mass with respect to the epoxy resin.

Examples of the inorganic filler include crystalline silica powder, meltable silica powder, quartz glass powder, talc, calcium silicate powder, zirconium silicate powder, alumina powder, calcium carbonate powder and the like, and crystalline silica powder and meltable silica. Powder is preferred.

The content of the inorganic filler in the resin composition of the present invention is preferably 30 to 90% by mass with respect to the entire resin composition.
When the resin composition of the present invention is used as a thermosetting molding material for forming a sealing material, it is preferable that the resin composition of the present invention contains a curing accelerator (P) and an inorganic filler.

A resin varnish can be obtained by blending a solvent with the resin composition of the present invention and dissolving the liquid polyvalent hydroxy resin and the maleimide compound (I) in the solvent.
The solvent is not particularly limited as long as it dissolves a liquid polyvalent epoxy resin, a maleimide compound (I), or the like, and a polar solvent is typically used. Examples of the polar solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, N, N-dimethylformamide, N-methyl-2-pyrrolidone, methanol, ethanol, butanol, ethyl acetate, butyl acetate, methyl cellosolve, and ethyl diglycol. Examples thereof include acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and tetrahydrofuran. As the solvent, one type may be used alone, or two or more types may be used in combination.

Examples of the release agent include various waxes such as carnauba wax.
Examples of the surface treatment agent include known silane coupling agents and the like.
Examples of the colorant include carbon black and the like.
Examples of the flexibility-imparting agent include silicone resin, butadiene-acrylonitrile rubber, and the like.

The curing of the resin composition of the present invention is preferably carried out by controlling the curing temperature to 100 to 250 ° C. As an example of the curing operation, there is a method of once curing at the above-mentioned suitable curing temperature for 30 seconds or more and 3 hours or less, and then further performing post-curing at the above-mentioned suitable curing temperature for 1 to 20 hours. ..

As described above, since the resin composition of the present invention contains a liquid polyhydric hydroxy resin satisfying a specific condition and the maleimide compound (I), it is flexible and flexible while ensuring sufficient heat resistance. A cured product having excellent toughness can be formed.
The factors for obtaining such an effect are considered as follows. ^{Since the unsaturated group contained in the long chain R 2} of the structural unit (u2) of the liquid polyhydric hydroxy resin reacts with the maleimide group of the maleimide compound (I), as compared with the case of using the conventional allylphenol resin, It is considered that the cured product has a low elastic modulus and high toughness. Further, since the liquid polyvalent hydroxy resin and the maleimide compound (I) are cured, it is considered that sufficient heat resistance is ensured.

Further, the cured product obtained by the resin composition of the present invention has a low high-temperature storage elastic modulus and excellent thermal stability, and has a low dielectric constant and dielectric loss tangent and excellent electrical characteristics. To improving the thermal stability and electrical properties, considered as R ² of the liquid polyhydroxy resin is reacted with a maleimide group of the maleimide compound (I) is due to be longer than the allyl group of allyl phenolic resin Be done.
As described above, the cured product of the resin composition of the present invention has high glass transition temperature, high toughness, low flexural modulus, low storage elastic modulus at high temperature, low dielectric constant, and low dielectric loss tangent, and thus has high functionality and high functionality. It is extremely useful as a molecular material.

Applications of the resin composition of the present invention include, for example, encapsulants for electronic parts such as semiconductors, electrical insulating materials, resins for copper-clad laminates, resists, resins for liquid crystal color filters, various coating agents, adhesives, and the like. Examples include build-up laminated board materials and fiber reinforced plastics (FRP).

<Resin varnish>
The resin varnish of the present invention comprises the resin composition of the present invention containing a liquid polyvalent hydroxy resin, a maleimide compound (I), and a solvent as essential components. By using the resin composition of the present invention, a laminated board such as a copper-clad laminated board can be manufactured.

The content of the solvent in the resin varnish is appropriately set according to the solid content concentration of the resin varnish. The solid content concentration of the resin varnish varies depending on the application, but is preferably 30 to 80% by mass, more preferably 50 to 70% by mass.
The solid content concentration of the resin varnish is the ratio of the mass of the resin varnish excluding the solvent to the total mass of the resin varnish.

The resin varnish of the present invention can be produced by mixing a maleimide compound (I), a liquid polyhydric hydroxy resin, and a solvent. Mixing of each component can be carried out by a conventional method. When or after mixing the maleimide compound (I), the liquid multivalent hydroxy resin, and the solvent, a curing reaction catalyst or other components may be further mixed, if necessary.

In the resin varnish of the present invention, the maleimide compound (I), the liquid polyvalent hydroxy resin and the solvent may be mixed, and then the maleimide compound (I) and the liquid polyvalent hydroxy resin may be pre-reacted. By performing the prereaction in the varnish state, it is possible to suppress the precipitation of the highly crystalline maleimide compound (I) from the resin varnish.

The reaction temperature at the time of carrying out the pre-reaction is preferably 50 to 150 ° C, more preferably 70 to 130 ° C, and even more preferably 80 to 120 ° C. If the reaction temperature is too low, the reaction will not proceed. Further, if the reaction temperature is too high, it becomes difficult to control the reaction, and it becomes difficult to stably obtain a resin varnish.

The cured product obtained from this resin varnish has a high glass transition temperature, high toughness, low storage elastic modulus at high temperature, low dielectric constant, and low dielectric loss tangent. In addition, it has excellent adhesion to other members (for example, copper foil used for copper-clad laminates, fibrous base materials such as glass cloth, etc.). Therefore, the resin varnish of the present invention is useful as a material for manufacturing laminated plates used for electronic parts.

<Manufacturing method of laminated board>
The method for producing a laminated board of the present invention is a method of obtaining a laminated board by heating and pressurizing a laminate containing a prepreg in which a fibrous base material is impregnated with the resin varnish of the present invention and curing the laminate.
The number of laminated prepregs in the laminate may be one layer or two or more layers. In the laminated product, a base material other than the prepreg may be laminated. Examples of other base materials include metal foils such as copper foils.

Examples of the fibers constituting the fibrous base material include inorganic fibers such as glass fiber, carbon fiber, ceramic fiber and stainless fiber; natural fiber such as cotton, linen and paper; and synthetic organic fiber such as polyester resin and polyamide resin. Can be mentioned. Any one of these fibers may be used alone, or two or more thereof may be used in combination.
The shape of the fibrous base material is not particularly limited, and examples thereof include short fibers, yarns, mats, and sheets.

The laminated board manufactured by the method for manufacturing a laminated board of the present invention includes a fiber-reinforced resin layer containing a fibrous base material and a cured product of a resin varnish. The number of fiber-reinforced resin layers included in the laminated board may be one layer or two or more layers. The laminated board may have a metal foil layer such as copper foil.

Examples of the method for producing the laminated board of the present invention include the following methods. The fibrous substrate is impregnated with a resin varnish, dried, and the solvent is removed to obtain a prepreg. A prepreg and another base material to be used as needed are laminated to form a laminate, and the laminate is heated and pressed to be cured to obtain a laminate.

The amount of the resin varnish impregnated in the fibrous base material is not particularly limited, and for example, the solid content of the impregnated resin varnish is about 30 to 50% by mass with respect to the fibrous base material (100% by mass). To be.
The heating temperature at the time of heating and pressurizing the laminate is preferably the above-mentioned curing temperature. The pressurizing condition is preferably ^{2 to 20 kN / m 2.}

The laminated board obtained by the method for producing a laminated board of the present invention includes a fiber-reinforced resin layer containing a fibrous base material and a cured product of the resin varnish of the present invention. In the fiber-reinforced resin layer, the cured product of the resin varnish has a high glass transition temperature, high toughness, low storage elastic modulus at high temperature, low dielectric constant, and low dielectric loss tangent. Further, when the metal foil layer is provided, the adhesion between the metal foil layer and the fiber reinforced resin layer and the adhesion between the fibrous base material and the cured product of the resin varnish in the fiber reinforced resin layer are also excellent. ing.

<Thermosetting molding material>
The thermosetting molding material of the present invention comprises the resin composition of the present invention. The thermosetting molding material of the present invention preferably does not contain a solvent.

<Encapsulant>
The encapsulant of the present invention comprises a cured product of the thermosetting molding material of the present invention.
The shape of the encapsulant is not particularly limited, and for example, a shape similar to that used in known semiconductors and the like can be adopted.
Examples of the method of forming the sealing material using the thermosetting molding material of the present invention include a method of sealing a semiconductor by using a transfer molding method, a compression molding method, or the like.

The encapsulant of the present invention has a high glass transition temperature, high toughness, low storage elastic modulus at high temperature, low dielectric constant, and low dielectric loss tangent. Therefore, it is difficult for damage to occur when exposed to a high temperature or due to an impact, and an electronic component having excellent reliability and electrical characteristics can be obtained.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the following description.
In each of the following examples, "%" indicates "mass%" unless otherwise specified.

[Mass average molecular weight (Mw), dispersity (Mw / Mn)]
The mass average molecular weight (Mw) and the degree of dispersion (Mw / Mn) were measured by gel permeation chromatography analysis (GPC) using the following measuring device and column as a standard substance as polystyrene.
Measuring device: Tosoh HLC8120GPC,
Column: TSKgel G3000H + G2000H + G2000H.

[Hydroxy group equivalent]
The hydroxyl group equivalent was measured by an acetylation method using acetic anhydride using an automatic titrator (COM-1700S manufactured by Hiranuma Sangyo Co., Ltd.).

[Unsaturated group equivalent]
^{13 The} unsaturated group equivalent was measured by C-NMR.

[viscosity]
The viscosity was measured with an E-type viscometer (manufactured by TOKIMEC) set at 25 ° C.

[Glass transition temperature (Tg)]
The obtained molded product is processed into a width of 10.0 mm, a length of 5.5 mm, and a thickness of 1.0 m, and a temperature rise rate of 2 ° C./min is used using a viscoelasticity measuring device (DMA7100 manufactured by Hitachi High-Tech Science Co., Ltd.). Tg was measured in the range of 30 ° C. to 400 ° C.

[Storage modulus]
The obtained molded product is processed into a width of 10.0 mm, a length of 5.5 mm, and a thickness of 1.0 m, and a temperature rise rate of 2 ° C./min is used using a viscoelasticity measuring device (DMA7100 manufactured by Hitachi High-Tech Science Co., Ltd.). The storage elastic modulus at 25 ° C. and 200 ° C. was determined by measuring in the range of 15 ° C. to 400 ° C.

[Bending elastic modulus, bending strength]
The flexural modulus and bending strength of the molded product were measured by a method according to JIS K 6911: 1995.

[Permittivity, dielectric loss tangent]
The obtained molded product was processed into a width of 50.0 mm, a length of 50.0 mm, and a thickness of 1.5 mm, and the dielectric constant and the dielectric loss tangent at 1 GHz were determined by the cavity resonance perturbation method.

<Manufacturing example 1>
As a refined cashew nut shell liquid (refined CNSL), GOLDEN CASHEW PRODUCTS PVT, trade name: CARDANOL was prepared. This purified CNSL has a cardanol content of 90.44%, a cardol content of 4.02%, and a methyl cardol content of 1.04%, and the total (active ingredient content) thereof is 95.5. %Met.
A glass flask with a content of 3 L equipped with a thermometer, a stirrer, and a cooling tube was charged with 300 g of purified CNSL, 6 g of phenol, 150 g of methanol, and 120 g of a 50% formaldehyde aqueous solution (2.0 mol, 40% with respect to purified CNSL). 133 g of a 30% aqueous sodium hydroxide solution was added dropwise to the mixed solution at 35 ° C. over 2 hours. Then, the methylolation reaction of purified CNSL was carried out at 35 ° C. for 6 hours. Next, 648 g (6 mol, 216% with respect to purified CNSL) of orthocresol was added, washed with water to remove the neutralized salt, and 6.49 g of oxalic acid was added to acidify the inside of the system, and 4 at 100 ° C. For hours, an addition reaction of orthocresol was carried out. Then, washing with water was performed, and then excess orthocresol was distilled off to obtain a liquid polyvalent hydroxy resin A.
The viscosity of the liquid polyvalent hydroxy resin A at 25 ° C. is 25.1 Pa · s, Mw is 1380, Mw / Mn is 1.492, the hydroxyl group equivalent is 203 g / eq, and the unsaturated group equivalent is 176.7 g / eq in total. there were. The total ratio of the constituent unit (u2) and the compound (m2) to the total mass of the liquid polyvalent hydroxy resin A is 75.4% (the balance is 24.6%), and the ratio of the compound (m2) is 6. It was 0.6%. These ratios were determined by the mass of the liquid polyvalent hydroxy resin A, the amount of purified CNSL used, and GPC (hereinafter, the same applies).

<Manufacturing example 2>
In a glass flask with an internal capacity of 3 L equipped with a thermometer, a stirrer, and a cooling tube, 300 g of the same purified CNSL used in Production Example 1, 150 g of methanol, and 90 g of a 50% aqueous formaldehyde solution (1.5 mol, relative to purified CNSL). 30%) was charged, and 133 g of a 30% aqueous sodium hydroxide solution was added dropwise at 35 ° C. over 2 hours to the mixed solution. Then, the methylolation reaction of purified CNSL was carried out at 35 ° C. for 6 hours. Then, 648 g (6 mol, 216% with respect to purified CNSL) of orthocresol was added, neutralized with 220 g of 30% acetic acid, washed with water to remove the neutralized salt, and 6.49 g of oxalic acid was added. Then, the inside of the system was made acidic, and an addition reaction of orthocresol was carried out at 100 ° C. for 4 hours. Then, washing with water was performed, and then excess orthocresol was distilled off to obtain a liquid polyvalent hydroxy resin B.
The viscosity of the liquid polyvalent hydroxy resin B at 25 ° C. is 7.8 Pa · s, Mw is 1326, Mw / Mn is 1.514, the hydroxyl group equivalent is 206 g / eq, and the unsaturated group equivalent is 185.1 g / eq in total. there were. The total ratio of the constituent unit (u2) and the compound (m2) to the total mass of the liquid polyvalent hydroxy resin B is 80.0% (the balance is 20.0%), and the ratio of the compound (m2) is 11. It was .2%.

<Manufacturing example 3>
In a glass flask with an internal capacity of 3 L equipped with a thermometer, a stirrer, and a cooling tube, 300 g of the same purified CNSL used in Production Example 1, 150 g of methanol, and 120 g of a 50% formaldehyde aqueous solution (2.0 mol, relative to purified CNSL). 40%) was charged, and 133 g of a 30% aqueous sodium hydroxide solution was added dropwise at 35 ° C. over 2 hours to the mixed solution. Then, the methylolation reaction of purified CNSL was carried out at 35 ° C. for 6 hours. Next, 648 g (6 mol, 216% with respect to purified CNSL) of orthocresol was added, washed with water to remove the neutralized salt, and 6.49 g of oxalic acid was added to acidify the inside of the system, and 4 at 100 ° C. For hours, an addition reaction of orthocresol was carried out. Then, washing with water was performed, and then excess orthocresol was distilled off to obtain a liquid polyvalent hydroxy resin C.
The viscosity of the liquid polyvalent hydroxy resin C at 25 ° C. was 24.4 Pa · s, Mw was 1374, Mw / Mn was 1.489, the hydroxyl group equivalent was 201 g / eq, and the unsaturated group equivalent was 175.2 g / eq in total. there were. The total ratio of the constituent unit (u2) and the compound (m2) to the total mass of the liquid polyvalent hydroxy resin C is 75.5% (the balance is 24.5%), and the ratio of the compound (m2) is 6. It was 3.3%.

<Manufacturing example 4>
For comparison, allylphenol formaldehyde resin D (manufactured by Gun Ei Chemical Industry Co., Ltd., product name: XPL-4437E) was prepared. The allylphenol formaldehyde resin D is liquid at room temperature and has a viscosity at 25 ° C. of 31 Pa. The total unsaturated group equivalent was 135.7 g / eq.

<Example 1>
The liquid polyvalent hydroxy resin A obtained in Production Example 1 and 4,4'-diphenylmethanebismaleimide (manufactured by Daiwa Kasei Kogyo Co., Ltd., product name: BMI-1100) have a molar ratio (maleimide group / unsaturated group). A resin composition was obtained by mixing in the blending amounts shown in Table 1 so as to be 1.
The resin composition is melted at 135 ° C., poured into a mold having a cavity having a width of 100 mm × length of 100 mm × thickness of 1 mm, press-molded at 200 ° C., and then heated at 230 ° C. for 5 hours to carry out a post-curing reaction. This was carried out to obtain a molded product having a width of 100 mm, a length of 100 mm and a thickness of 1 mm.

<Examples 2 to 4, Comparative Examples 1 and 2>
A resin composition was prepared in the same manner as in Example 1 except that the composition of the resin composition was changed as shown in Table 1, and a molded product was prepared.
Table 2 shows the evaluation results of the molded product obtained in each example.

The abbreviations in Table 1 have the following meanings.
BMI-1100: 4,4'-diphenylmethanebismaleimide (manufactured by Daiwa Kasei Kogyo Co., Ltd., product name: BMI-1100),
BMI-2300: Polyphenylmethanemaleimide (manufactured by Daiwa Kasei Kogyo Co., Ltd., product name: BMI-2300).

As shown in Table 2, the cured products of Examples 1 to 4 using the resin composition containing the specific liquid polyvalent hydroxy resin specified in the present invention and the maleimide compound (I) have a high glass transition temperature and heat resistance. It was excellent in bending strength and toughness, had a low storage elastic modulus at 200 ° C. (high temperature storage elastic modulus) and was excellent in thermal stability, and had a low dielectric constant and dielectric loss tangent and was excellent in electrical characteristics.
On the other hand, the cured products of Comparative Examples 1 and 2 in which the allylphenol formaldehyde resin was used instead of the liquid polyhydric hydroxy resin had lower bending strength and inferior toughness as compared with Examples 1 to 4, and had a high high temperature storage elastic modulus. It was high and inferior in thermal stability, and had high dielectric constant and dielectric loss tangent and inferior electrical characteristics.

Claims (9)

It contains a liquid multivalent hydroxy resin and a maleimide compound having two or more maleimide groups in one molecule.
The liquid multivalent hydroxy resin has a structural unit represented by the following formula (u1) and a structural unit represented by the following formula (u2), and contains a compound represented by the following formula (m2). ,
The ratio of the total mass of the structural unit represented by the formula (u2) and the compound represented by the formula (m2) to the total mass of the liquid polyvalent hydroxy resin is 70 to 90% by mass.
A resin composition having a mass average molecular weight of the liquid polyvalent hydroxy resin of 800 to 1600.

[In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is a linear or branched hydrocarbon group having 10 to 25 carbon atoms including an unsaturated group, and X is a hydrogen atom or a hydroxyl group. m and n are independently 0 or 1, respectively, and Y is a hydrogen atom or a methyl group. -* Indicates a bond. At least one of the three bonds in formula (u1) is bound to another building block, at least one of the three bonds in formula (u2) is bound to another building block, and the other Bonders that do not bond to a building block bond to a hydrogen atom. The benzene ring in each structural unit and the benzene ring in the other structural units are bonded via a methylene group. ] The first aspect of claim 1, wherein the total molar ratio (maleimide group / unsaturated group) of the maleimide groups of the maleimide compound to the total of unsaturated groups of the liquid polyvalent hydroxy resin is 0.5 to 3.0. The resin composition according to the description. The resin composition according to claim 1 or 2, further comprising an epoxy resin. The resin composition according to any one of claims 1 to 3, further comprising a curing accelerator that promotes a curing reaction between the liquid polyvalent hydroxy resin and the maleimide compound, and an inorganic filler. The resin composition according to any one of claims 1 to 4, further comprising a solvent. A resin varnish comprising the resin composition according to claim 5. A method for producing a laminated board, wherein a laminated board containing a prepreg impregnated with the resin varnish according to claim 6 is heated and pressed and cured to obtain a laminated board. A thermosetting molding material comprising the resin composition according to claim 4. A sealing material made of a cured product of the thermosetting molding material according to claim 8.