JP6476527B2 - Liquid polyvalent hydroxy resin, production method thereof, curing agent for epoxy resin, epoxy resin composition, cured product thereof and epoxy resin - Google Patents

Description

  The present invention relates to a liquid polyvalent hydroxy resin, a production method thereof, a curing agent for epoxy resin, an epoxy resin composition, a cured product thereof, and an epoxy resin.

Epoxy resin compositions containing an epoxy resin, a curing agent, and the like are used for various applications by utilizing their thermosetting properties. For example, in the field of electronic materials, in order to protect semiconductor chips and connection members from various external environments (temperature, humidity, stress, etc.), sealing with a thermosetting sealing material is performed. Epoxy resin compositions are widely used as sealing materials. A phenolic curing agent is widely used as a curing agent for the epoxy resin.
In recent years, with the increase in processing capability of semiconductor elements, higher integration and higher performance of semiconductors have progressed, and the demand for reliability of resin materials used therefor has become stricter year by year.

Phenolic curing agents often exhibit solid or semi-solid due to hydrogen bonding of phenolic hydroxyl groups, but liquid ones are also known. In recent years, the use of liquid sealing materials such as underfill materials has expanded, and accordingly, the need for liquid phenolic curing agents has increased. In addition, the characteristics required for liquid phenolic curing agents are more severe.
For example, the underfill material is injected into a gap between the package and the wiring board and cured after connecting a surface mount type package such as a BGA (Ball Grid Array) and an electrode on the wiring board. The cured product relaxes the difference in thermal expansion coefficient and the elastic modulus between the semiconductor chip and the wiring board, thereby improving connection reliability. However, this gap is becoming narrower due to recent high integration of semiconductors. . Therefore, further lowering of the viscosity of the underfill material and its raw material is required. Also, if the difference in thermal expansion coefficient and elastic modulus cannot be relaxed sufficiently, warping, cracking, and fracture of the joint will occur when stress such as temperature cycle or impact is applied after mounting, causing problems in the semiconductor . Therefore, further reduction in elastic modulus of the cured product is required.
However, since the epoxy resin composition using a phenolic curing agent is three-dimensionally cured, the cured product tends to have a high elastic modulus.

As a liquid phenol type curing agent, a phenol resin (allyl phenol resin) in which an allyl group is introduced at an ortho position of a phenolic hydroxyl group is generally used (for example, Patent Document 1). The allylphenol resin tends to be liquid at room temperature because the allyl group inhibits hydrogen bonding of the phenolic hydroxyl group.
However, the elastic modulus of the cured product cannot be made sufficiently low. Moreover, even if an allyl group is introduced, it is difficult to obtain sufficient fluidity (low viscosity) at room temperature. If the allyl group introduction ratio is increased to reduce the viscosity, there is a concern that the molecular weight may be decreased and the yield may be decreased. Moreover, compared with the case where no allyl group is introduced, the curing rate of the epoxy resin composition tends to be slow.

In order to lower the viscosity and lower the elastic modulus of the cured product, a polyvalent hydroxy resin obtained by reacting allylphenol, a phenol substituted with a long-chain hydrocarbon group, and formaldehyde has been proposed (Patent Literature). 2).
However, since this polyvalent hydroxy resin has an allyl group and a long-chain hydrocarbon group, the curing rate of the epoxy resin composition is slower than the allylphenol resin, which may reduce the productivity of semiconductor devices and the like. .

As a general method for reducing the elastic modulus of a cured product, there is a method of blending a rubber component (for example, Patent Document 3).
However, since the rubber component is generally low in polarity, the compatibility in the epoxy resin composition is low. Moreover, there exists a concern about the viscosity increase of an epoxy resin composition by mix | blending a rubber component.

JP 2010-241877 A Japanese Patent Laying-Open No. 2015-89940 JP 2007-2032 A

  The present invention has been made in view of the above circumstances, and even when no allyl group is introduced, it exhibits a low-viscosity liquid and a cured product having a low elastic modulus when used as a curing agent for epoxy resins. It aims at providing the polyvalent hydroxy resin obtained, its manufacturing method, the hardening | curing agent for epoxy resins using the said polyvalent hydroxy resin, an epoxy resin composition, hardened | cured material, and an epoxy resin.

The present invention has the following aspects.
(1) having a structural unit represented by the following formula (u1) and a structural unit represented by the following formula (u2);
The total content of the structural unit represented by the formula (u2) and the compound represented by the following formula (m2) is 70 to 90% by mass with respect to the whole liquid polyvalent hydroxy resin,
A liquid polyhydroxy resin having a mass average molecular weight of 800 to 1600.

[Wherein, 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, X is a hydrogen atom or a hydroxyl group, and m and n are respectively Independently 0 or 1, Y is a hydrogen atom or a methyl group. ]
(2) The liquid polyvalent hydroxy resin according to (1), which does not have a structural unit represented by the following formula (u31).

[Wherein R ³ represents an allyl group. ]
(3) The liquid polyvalent hydroxy resin according to (1) or (2), wherein the viscosity at 25 ° C. is 100 Pa · s or less.
(4) The method for producing a liquid polyvalent hydroxy resin according to any one of (1) to (3),
Reaction of a compound represented by the following formula (m2) and formaldehyde, or a compound represented by the following formula (m1), a compound represented by the above formula (m2) and formaldehyde in the presence of a basic catalyst. And producing a liquid polyvalent hydroxy resin by reacting the reaction product with the compound represented by the formula (m1) in the presence of an acidic catalyst.

[Wherein, 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, X is a hydrogen atom or a hydroxyl group, and Y is a hydrogen atom or It is a methyl group. ]
(5) The amount of the reaction in the presence of the basic catalyst of formaldehyde is 10 to 80% by mass with respect to the compound represented by the formula (m2),
The total amount of the compound represented by the formula (m1) to be reacted in the presence of the basic catalyst and the amount to be reacted in the presence of the acidic catalyst is 72 with respect to the compound represented by the formula (m2). The manufacturing method of the liquid polyvalent hydroxy resin as described in (4) which is -361 mass%.
(6) A curing agent for epoxy resin comprising the liquid polyvalent hydroxy resin according to any one of (1) to (3).
(7) An epoxy resin composition comprising an epoxy resin and the epoxy resin curing agent according to (6).
(8) Hardened | cured material which hardened | cured the epoxy resin composition as described in said (7).
(9) An epoxy resin in which at least a part of hydroxyl groups of the liquid polyvalent hydroxy resin according to any one of (1) to (3) is epoxidized.

  According to the present invention, even when no allyl group is introduced, a polyhydric hydroxy resin that exhibits a low-viscosity liquid and can be obtained as a cured product having a low elastic modulus when used as a curing agent for epoxy resins, and a method for producing the same And a curing agent for epoxy resins, an epoxy resin composition, a cured product, and an epoxy resin using the polyvalent hydroxy resin.

<Liquid polyvalent hydroxy resin>
The liquid polyvalent hydroxy resin of the present invention has a structural unit represented by the following formula (u1) (hereinafter also referred to as structural unit (u1)) and a structural unit represented by the following formula (u2) (hereinafter referred to as structural). Unit (u2)). The liquid polyvalent hydroxy resin of the present invention may further have a structural unit other than the structural unit (u1) and the structural unit (u2) (hereinafter also referred to as the structural unit (u3)).
“Structural unit” indicates a unit constituting the polymer.
The liquid polyvalent hydroxy resin of the present invention may contain a non-polymer. For example, the raw materials (phenols etc.) used for the production of the liquid polyvalent hydroxy resin may remain.
The liquid polyvalent hydroxy resin of the present invention typically has either one or both of phenol and methylphenol (a compound represented by the formula (m1) described later) and a compound represented by the following formula (m2) ( Hereinafter, phenols containing compound (m2)) are polycondensed with formaldehyde.
The liquid polyvalent hydroxy resin of the present invention may contain the compound (m2). For example, although the unreacted compound (m2) may remain during the polycondensation described above, the compound (m2) has a high boiling point and cannot be removed by distillation and tends to remain in the liquid polyhydroxy resin.

［式中、Ｒ^１は水素原子またはメチル基であり、Ｒ^２は炭素数１０〜２５の直鎖または分岐状の炭化水素基であり、Ｘは水素原子または水酸基であり、ｍおよびｎはそれぞれ独立に０または１であり、Ｙは水素原子またはメチル基である。］

[Wherein, 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, X is a hydrogen atom or a hydroxyl group, and m and n are respectively Independently 0 or 1, Y is a hydrogen atom or a methyl group. ]

“− *” Indicates a bond. At least one of the three bonds in the formula (u1) is bonded to 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 coupled to another structural unit (another structural unit (u2), structural unit (u1), etc.). Of the bonds in each formula, bonds not bonded to other structural units are bonded to a 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 present in the same molecule and the structural units (u1) are directly bonded to each other, the benzene ring in each structural unit (u1) is bonded via a methylene group. , Do not join 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 bonded to a hydrogen atom. In the case of bonding to another structural unit, the bond is bonded 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), or the like. To do.
The bond extending from the methylene group in the formula (u1) is bonded to the benzene ring of another structural unit (the structural unit (u2), another structural unit (u1), or the like).

The bond extending from the benzene ring in formula (u2) is bonded to another structural unit or bonded to a hydrogen atom. In the case of bonding to another structural unit, the bond is bonded to the methylene group of the other structural unit (such as 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. A bond (-*) is shown. That is, they are bonded to other structural units or bonded to hydrogen atoms. In the case of bonding 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 the formula (u2) is 1 (or n is 1), — (CH ₂ ) _m — * (or — (CH ₂ ) _n — *) is a methylene group, Are bonded to the benzene ring of the structural unit (structural unit (u1), another structural unit (u2)) or 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 another structural unit. That is, two methyl groups are not bonded to the benzene ring in 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 formula (u1), the bonding position of R ^{1 in} the benzene ring is the position where the hydroxyl group is bonded (position 1) because it is inexpensive and the synthesized resin easily liquefies. The ortho position (2nd or 6th position) is preferred.
The bonding positions of the single bond and the methylene group in 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 where the hydroxyl group is bonded (1st position).

The structural unit (u1) may consist only of a structural unit (hereinafter also referred to as a cresol unit) in which R ¹ is a methyl group, and a structural unit (hereinafter referred to as a phenol unit) in which R ¹ is a hydrogen atom. It may be composed of only cresol units and phenol units.
In the structural unit (u1), the higher the proportion of the cresol unit, the lower the viscosity of the polyvalent hydroxy resin, the longer the gel 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 polyvalent hydroxy resin, the shorter the gel time, the higher the elastic modulus of the cured product, and the higher the glass transition temperature. The ratio between the cresol unit and 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.
0-100 mass% is preferable with respect to the whole quantity (100 mass%) of a structural unit (u1), and, as for content of a cresol unit, 30-100 mass% is more preferable.
Therefore, 0-100 mass% is preferable with respect to the whole quantity of a structural unit (u1), and, as for content of a phenol unit, 0-70 mass% is more preferable.
Alternatively, the content of the phenol unit is preferably 10% by mass or less with respect to the structural unit (u2).

In formula (u2), R ² is a linear or branched hydrocarbon group having 10 to 25 carbon atoms. When the number of carbon atoms is 10 or more, it is easy to lower the viscosity of the liquid polyvalent hydroxy resin at room temperature, and it is easy to obtain a cured product having a low elastic modulus. When the number of carbon atoms is 25 or less, the heat resistance of the cured product is good.
10-25 are preferable and, as for carbon number of the said hydrocarbon group, 15-20 are more preferable.
The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group having an unsaturated bond (carbon-carbon double bond, carbon-carbon triple bond, etc.). The number of unsaturated bonds contained in the unsaturated hydrocarbon group may be one or two or more.
Specific examples of the hydrocarbon group include — (CH ₂ ) ₁₄ CH ₃ , — (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.
In formula (u2), X is preferably a hydrogen atom in terms of low water absorption of the cured product.

In the formula (u2), the bonding position of R ^{2 in} the benzene ring is preferably the meta position (the 3rd position or the 5th position) with respect to the position where the hydroxyl group is bonded (the 1st position) in terms of reactivity with formaldehyde. When X is a hydroxyl group, the 1-position indicates not the X bonding position but the hydroxyl bonding position shown as “OH” in the formula.
The bonding positions of X and Y in the benzene ring are not particularly limited. When X is a hydroxyl group, from the viewpoint of reactivity with formaldehyde, the meta position is preferred with respect to the position (the 1st position) where the hydroxyl group is represented as “OH” in the formula. When Y is a methyl group, the ortho position is preferred with respect to the position to which the hydroxyl group is bonded (position 1).
The bonding positions of the single bond, — (CH ₂ ) _m — * and — (CH ₂ ) _n — * in 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 where the hydroxyl group is bonded (1st position).

  Examples of the structural unit (u3) that the liquid polyvalent hydroxy resin of the present invention may have include a structural unit represented by the following formula (u31) (hereinafter also referred to as a structural unit (u31)). Can be mentioned.

［式中、Ｒ^３はアリル基である。］

[Wherein R ³ represents an allyl group. ]

  The bond extending from the benzene ring in formula (u31) is bonded to another structural unit or bonded to a hydrogen atom in the same manner as the bond extending from the benzene ring in formula (u1). In the case of bonding to another structural unit, the bond is bonded to the methylene group of the other structural unit. Moreover, the bond extending from the methylene group is bonded to the benzene ring of another structural unit.

In the liquid polyvalent hydroxy resin of the present invention, the total content of the structural unit (u2) and the compound (m2) is 70 to 90% by mass with respect to the entire liquid polyvalent hydroxy resin, and 70 to 85% by mass. Particularly preferred.
Structural units (u2) and the compound (m2) both are those having ^{R 2.} If the content of the structural unit (u2) and the compound (m2) is equal to or higher than the above lower limit value, the liquid polyvalent group can be used even if no allyl group is introduced (for example, the structural unit (u31) is not present). Hydroxy resin has low viscosity at room temperature. Moreover, when used as a curing agent for epoxy resins, a cured product having a low elastic modulus is obtained. If content of a structural unit (u2) and a compound (m2) is below the said upper limit, sclerosis | hardenability and heat resistance are favorable.
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 content of the structural unit (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. This can be confirmed by a known analysis method.
The total content of the structural unit (u2) and the compound (m2) in the liquid polyvalent hydroxy resin is, for example, formaldehyde relative to the compound (m2) when the liquid polyvalent hydroxy resin is produced by the production method (i) described later And the reaction conditions (catalyst amount / species, temperature, time) and the like.

The remainder obtained by removing the structural unit (u2) and the compound (m2) from the liquid polyvalent hydroxy resin of the present invention contains phenols and formaldehyde other than the compound (m2) from the viewpoint of environmental aspect and curing rate with the epoxy resin. Preferably not.
Therefore, the remainder obtained by removing the structural unit (u2) and the compound (m2) from the liquid polyvalent hydroxy resin of the present invention is the structural unit (u1) or the structural unit (u1) and the structural unit (u3). The structural unit (u1) is particularly preferable.

  In the liquid polyvalent hydroxy resin of the present invention, the content of the structural unit (u31) is preferably 10% by mass or less, particularly 0% by mass with respect to the structural unit (u2) from the viewpoint of the curing rate with the epoxy resin. preferable. That is, it is particularly preferable that the liquid polyvalent hydroxy resin of the present invention does not have the structural unit (u31).

The mass average molecular weight (Mw) of the liquid polyvalent hydroxy resin of the present invention 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 polyvalent hydroxy resin at 25 ° C. When Mw is not more than the above upper limit, the liquid polyvalent hydroxy resin exhibits excellent fluidity at room temperature. When Mw is not less than the above lower limit, the reactivity with the epoxy resin is excellent, and the heat resistance of the cured product is good.
The dispersity (Mw / number average molecular weight (Mn)) of the liquid polyvalent hydroxy resin of the present invention is preferably 1.4 to 1.6.
In the present invention, 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 of the present invention 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 above upper limit value, the fluidity is excellent. The lower the viscosity at 25 ° C. of the liquid polyhydroxy resin, the better, 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 mass average molecular weight (Mw) of the liquid polyvalent hydroxy resin, the total content of the structural unit (u2) and the compound (m2).

(Method for producing liquid polyvalent hydroxy resin)
The liquid polyvalent hydroxy resin of the present invention comprises a compound represented by the following formula (m1) (hereinafter also referred to as compound (m1)), a compound (m2) represented by the following formula (m2), formaldehyde, Can be made to react.
When the compound (m1), the compound (m2), and formaldehyde are reacted, an addition reaction (methylolation reaction) of formaldehyde with respect to the compound (m1) or the compound (m2), and the resulting methylol compound and the compound (m1) or compound ( The condensation reaction with m2) proceeds. Thereby, a liquid polyvalent hydroxy resin is produced.
Along with the compounds (m1), (m2) and formaldehyde, other phenols other than the compounds (m1) and (m2) may be reacted.

［式中、Ｒ^１は水素原子またはメチル基であり、Ｒ^２は炭素数１０〜２５の直鎖または分岐状の炭化水素基であり、Ｘは水素原子または水酸基であり、Ｙは水素原子またはメチル基である。］

[Wherein, 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, X is a hydrogen atom or a hydroxyl group, and Y is a hydrogen atom or It is a methyl group. ]

R ¹ in formula (m1) is the same as R ¹ in formula (u1).
The compound (m1) used in the reaction may consist of a single compound or a mixture of two or more. 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 in that 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 thereof. For example, cashew nut shell liquid and purified product thereof, cardanol, cardol (also referred to as curdle), 2-methylcardol. Anacardic acid, urushiol and the like.
As compound (m2), cashew nut shell liquid or purification thereof is relatively inexpensive, easy to control the reactivity, and easy to obtain a cured resin having a low elastic modulus because the resulting resin is easily liquid. Things are preferred. Cashew nut shell liquid often contains a plurality of compounds (m2) containing cardanol.
The cashew nut shell liquid or a purified product thereof has a cardanol content of 70 to 100% by mass, a cardol content of 0 to 25% by mass, and a methyl cardanol with respect to the total mass of the cashew nut shell liquid or the purified product thereof. Is preferably 0 to 5%, and the total amount of cardanol, cardol, and methylcardanol (active ingredient amount) is 70% by mass or more.

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

As a manufacturing method of a liquid polyvalent hydroxy resin, the following manufacturing 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 reacted with each other. To obtain a liquid polyvalent hydroxy resin by reacting in the presence of an acidic catalyst.

Of the compound (m1) and the compound (m2), the compound (m2) is less reactive with formaldehyde. Therefore, when these are reacted with formaldehyde all at once, the unreacted compound (m2) tends to remain in the reaction product. When the compound (m2) remains in the liquid polyvalent hydroxy resin, the cured physical properties are deteriorated. Further, since the compound (m2) has a high boiling point, the remaining compound (m2) cannot be easily removed.
Therefore, first, before reacting the compound (m1), the compound (m2) is first reacted (reacted in the absence of the compound (m1)) or out of the total amount used for the production of the liquid polyvalent hydroxy resin. The reaction is carried out with the compound (m2) in the presence of a part of the compound (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 the compound (m1), 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 (m1) and the compound (m2), respectively. The methylol body represented by the formula (3) is produced.
By adding the compound (m1) to the methylol body thus produced, the compound (m2) can be prevented from remaining in the liquid polyvalent hydroxy resin.

［式中、Ｒ^１、Ｒ^２、Ｘ及びＹはそれぞれ前記と同様であり、ｋは１〜３の整数であり、ｈは１〜３の整数である。］

[Wherein R ¹ , R ² , X and Y are the same as defined above, k is an integer of 1 to 3, and h is an integer of 1 to 3, respectively. ]

The reaction between the reaction product and the compound (m1) proceeds even in the presence of the basic catalyst, but in the presence of the basic catalyst, the methylol bodies generated in the first stage reaction react to form a structural unit ( Side reactions such as a reaction in which a structure composed only of u2) is generated and a reaction in which a methylol body is reacted to form a methylol body are more likely to occur, and the mass average molecular weight is likely to be large. .
On the other hand, in the presence of an acidic catalyst, the reaction between the methylol produced in the first stage reaction and the compound (m1) in excess tends to preferentially proceed, and the formaldehyde produced by the reaction of the methylol is excessive. It reacts preferentially with the compound (m1) in the above, and the side reaction as described above hardly occurs. Therefore, it is easy to obtain a liquid polyhydroxy resin having a mass average molecular weight controlled to the upper limit or less.

Hereinafter, the case where a liquid polyvalent hydroxy resin is produced by the production method (i) will be described in detail.
In the production method (i), first, a first-stage reaction is performed in which the compound (m2) and formaldehyde or the compound (m1), the compound (m2), and formaldehyde are reacted in the presence of a basic catalyst.
The compound (m2) is generally used in the first step for the entire amount used for the production of the liquid polyvalent hydroxy resin.
30 mass% or less is preferable with respect to a compound (m2), and, as for the quantity of the compound (m1) used for reaction of the 1st step | paragraph, 10 mass% or less is more preferable. If it is below the said upper limit, there exists a tendency for the viscosity of the polyvalent hydroxy resin obtained to become 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 not having the structural unit (u2) increases, or the amount of the compound (m2) remaining unreacted increases. Or the cured material properties may be reduced. Therefore, from the viewpoint of obtaining more excellent cured properties, the amount of phenol used in the first-stage reaction is preferably 10% by mass or less with respect to the total amount of the compound (m2).
Formaldehyde may be a solid or an aqueous solution. It is preferable to use an aqueous solution because it is inexpensive and the reaction can be easily controlled.

The amount of formaldehyde to be reacted in the presence of a basic catalyst of formaldehyde, that is, the amount of formaldehyde to be reacted with compound (m2) or with compound (m1) and compound (m2) in the first stage reaction, is relative to compound (m2). 10 to 80% by mass is preferable, and 20 to 60% by mass is more preferable.
0.5-4.0 are preferable and, as for the molar ratio (formaldehyde / compound (m2)) of formaldehyde and a compound (m2), 1.0-3.0 are more preferable.
As the amount of formaldehyde is smaller within the above range, the total content of the structural unit (u2) and the compound (m2) in the liquid polyvalent hydroxy resin tends to increase. As the amount of formaldehyde is larger within the above range, the ratio of the compound (m2) to the total content tends to decrease.
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 glass transition temperature and curing rate may be lowered. If the amount of formaldehyde is too large, excess formaldehyde remains in the produced liquid polyvalent hydroxy resin, and it is necessary to remove the formaldehyde.
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 (total amount of cardanol, cardol, and methyl cardanol) of cashew nut shell liquid 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.), alkaline earth metal oxides and hydroxides such as calcium, magnesium, barium, sodium carbonate And alkaline substances such as A basic catalyst may be used individually by 1 type, or may use 2 or more types together.

In the first stage reaction, the amount of the basic catalyst used is 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 mass% is preferable and 6.7-20 mass% is more preferable.
Molar ratio (basic catalyst / {compound (m1) + compound (if the compound (m1) is not reacted, only the compound (m2))) of the basic catalyst and the total of the compound (m1) and the compound (m2) m2)}) is preferably from 0.1 to 3.0, more preferably from 0.5 to 1.5.
If the amount of the basic catalyst used is too small, the reaction rate is slow, and if the amount used is too large, the reaction proceeds rapidly and it becomes 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, or butanol. Thereby, it can prevent that a compound (m2) and a reaction product aggregate during the 1st step | paragraph reaction.
C1-C4 alcohol may be used individually by 1 type, or may use 2 or more types together. 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 relative 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 the 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) methylolated in the first stage reaction (methylol form of formula (3)) is an alkyl group of an alcohol having 1 to 4 carbon atoms (hereinafter abbreviated as R). ) To form —CH ₂ O—R (capped methylol body). Thereby, compared with the case where a methylol group exists as it is, a side reaction in which methylol bodies of the compound (m2) react with each other in the second stage reaction is less likely to occur.
On the other hand, since the methylol body and the capped methylol body easily react with the compound (m1) present in excess, the desired resin is 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 does not proceed. If it is too high, it becomes difficult to control the reaction, and it becomes difficult to stably obtain the target liquid polyvalent 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, a second-stage reaction is performed 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 72-361 mass% is preferable with respect to the compound (m2) used by reaction of the 1st step | paragraph, and, as for the total amount with the usage-amount of the compound (m1) in, 108-324 mass% is more preferable.
The molar ratio of the total amount of the compound (m1) used in the first stage reaction and the compound (m1) used in the second stage reaction to the compound (m2) used in the first stage reaction ( The compound (m1) / compound (m2)) is preferably 2.0 to 10.0, and more preferably 3.0 to 9.0.
When the ratio of the compound (m1) is too low, the mass average molecular weight of the liquid polyvalent hydroxy resin increases and the viscosity at room temperature increases. If the ratio of the compound (m1) is too high, the yield decreases and the cost increases.

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, and zinc chloride. An acidic catalyst may be used individually by 1 type, or may use 2 or more types together.
Of the above, hydrochloric acid, sulfuric acid, oxalic acid, and p-toluenesulfonic acid are preferable because they can be obtained relatively inexpensively.

In the second stage reaction, the amount of the acidic catalyst used is preferably 0.04 to 12.6% by mass, and 0.4 to 4.2% by mass with respect to the compound (m2) used in the first stage reaction. Is more preferable.
The molar ratio of the acidic catalyst to the compound (m2) (acidic catalyst / compound (m2)) is preferably 0.001 to 0.3, and more preferably 0.01 to 0.1.
If the amount of the acidic catalyst used is too small, the reaction rate is slow, and if the amount used is too large, the reaction proceeds rapidly and it becomes 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 does not proceed. If it is too high, it becomes difficult to control the reaction, and it becomes difficult to stably obtain the target liquid polyvalent hydroxy resin.

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

In the production method (i), when other phenols are reacted together 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, the reaction may be performed during the first stage reaction, the reaction may be performed during the second stage reaction, or the reaction may be performed during both of them.
When the other phenols are allylphenol, allylphenol has higher reactivity with formaldehyde than compound (m2), like compound (m1). Therefore, when other phenols are allylphenol, after making a compound (m2) and formaldehyde react, it is preferable to make it react with the reaction product. That is, it is preferable to react the compound (m2) and formaldehyde in the presence of a basic catalyst, and react the reaction product, the compound (m1) and other phenols in the presence of an acidic catalyst.

(Use of liquid polyhydroxy resin)
The use of the liquid polyvalent hydroxy resin of the present invention is not particularly limited, and can be used for various known uses as the use of the liquid polyvalent hydroxy resin.
For example, since the liquid polyvalent hydroxy resin of the present invention has a plurality of hydroxyl groups, a curing agent (crosslinking agent) for a compound having a functional group (epoxy group, carboxyl group, isocyanate group, halide, etc.) that reacts with the hydroxyl group. Can be used as The liquid polyvalent hydroxy resin of the present invention is suitable as a curing agent for epoxy resins.
Moreover, the liquid polyvalent hydroxy resin of this invention can be used as a material for manufacturing an epoxy resin. For example, an epoxy resin can be obtained by epoxidizing a hydroxyl group of a liquid polyvalent hydroxy resin.

(Function and effect)
The liquid polyvalent hydroxy resin of the present invention has the structural unit (u1) and the structural unit (u2), and the total content of the structural unit (u2) and the compound (m2) is 70 to 90% by mass. In addition, when the mass average molecular weight is 800 to 1600, it exhibits low viscosity at room temperature. Moreover, when the liquid polyvalent hydroxy resin of this invention is used as a hardening | curing agent for epoxy resins, a low elasticity modulus can be provided to hardened | cured material.
In particular, when the liquid polyvalent hydroxy resin of the present invention does not have the structural unit (u31), the reactivity between the liquid polyvalent hydroxy resin of the present invention and the epoxy resin is good, and an epoxy resin composition containing these The curing rate of the product is sufficiently fast. In the case of an allylphenol resin conventionally used as a liquid phenolic curing agent, it is necessary to increase the amount of allyl groups introduced in order to obtain a sufficiently low viscosity. However, especially when the allyl group is introduced at the ortho position of the hydroxyl group, the reaction between the hydroxyl group and the epoxy group is inhibited, and the curing rate of the epoxy resin composition becomes slow.
R ² is considered to contribute to lowering the viscosity by inhibiting hydrogen bonding of the hydroxyl group. R ² is also considered to contribute to lowering the elastic modulus.
When R ¹ is a methyl group, R ¹ is also considered to contribute to the reduction in viscosity by inhibiting the hydrogen bonding of the hydroxyl group. Moreover, even if R ¹ is bonded to the ortho position of the hydroxyl group, it is difficult to inhibit the reaction between the hydroxyl group and the epoxy group, and the viscosity can be lowered without impairing the curing rate of the epoxy resin composition. When R ¹ is a hydrogen atom, the reaction between the hydroxyl group and the epoxy group is less likely to be inhibited.

<Curing agent for epoxy resin>
The curing agent for epoxy resin of the present invention comprises the above-mentioned liquid polyvalent hydroxy resin of the present invention. That is, the preferable aspect of the curing agent for epoxy resins of the present invention is the same as the preferable aspect of the liquid polyvalent hydroxy resin of the present invention.

<Epoxy resin>
The epoxy resin of the present invention is obtained by epoxidizing at least part of the hydroxyl groups of the liquid polyhydroxy resin of the present invention.
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 (such as the phenolic hydroxyl group of the structural unit (u1) or the structural unit (u2)) of the liquid polyvalent hydroxy resin is − An epoxy resin having a structure of OZ (where Z is a glycidyl group) can be obtained.

<Epoxy resin composition>
The epoxy resin composition of the present invention includes an epoxy resin and the aforementioned curing agent for epoxy resin of the present invention.
The epoxy resin composition of this invention may further contain other components other than the epoxy resin and the hardening | curing agent for epoxy resins of this invention as needed.
The epoxy resin composition of the present invention may contain a solvent, if necessary. When the epoxy resin composition of the present invention is used as a semiconductor sealing material (liquid sealing material or the like), it is preferable that no solvent is contained.

The epoxy resin is not particularly limited and may be a known epoxy resin, such as a phenol novolac type epoxy resin, an orthocresol novolac type epoxy resin, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a biphenol type epoxy resin, Naphthalene type epoxy resin, anthracene type epoxy resin, naphthol type epoxy resin, xylylene type epoxy resin, biphenyl type epoxy resin, triphenylmethane type epoxy resin, dicyclopentadiene type epoxy resin, stilbene type epoxy resin, sulfur atom-containing epoxy resin, A phosphorus atom containing epoxy resin etc. are mentioned. Any one of these epoxy resins may be used alone, or two or more thereof may be used in combination.
As the epoxy resin, the epoxy resin of the present invention (an epoxy resin in which at least a part of the hydroxyl groups of the liquid polyvalent hydroxy resin of the present invention is epoxidized) may be used.

  In the epoxy resin composition, the content of the curing agent for epoxy resin of the present invention is such that the equivalent ratio of the epoxy group of the epoxy resin to the hydroxyl group of the curing agent for epoxy resin of the present invention (epoxy group / hydroxyl group) is 0.7. It is preferable that it is the quantity used as -1.5. The epoxy group / hydroxyl group is more preferably 0.9 to 1.1. When the epoxy group / hydroxyl group is within the above range, the obtained cured product has a lower elastic modulus.

Examples of the other components include a curing agent other than the epoxy resin curing agent of the present invention (hereinafter also referred to as other curing agent), a curing accelerator, a filler (filler), a release agent, a surface treatment agent, and a coloring agent. Agents, flexibility imparting agents and the like.
As other curing agents, those conventionally known as curing agents used for epoxy resins can be used, such as phenol resins such as phenol novolac resins and triphenylmethane type phenol resins, acid anhydrides, amine resins and the like. It is done.

It does not specifically limit as a hardening accelerator, A well-known hardening accelerator may be sufficient. Examples thereof include phosphorus compounds, tertiary amines, imidazole compounds, organic acid metal salts, Lewis acids, amine complex salts, and the like. Examples of the phosphorus compound include triphenylphosphine, tris-2,6-dimethoxyphenylphosphine, tri-p-tolylphosphine, and triphenyl phosphite. Examples of the tertiary amine include 2-dimethylaminomethylphenol, benzyldimethylamine, α-methylbenzyldimethylamine, 1,8-diazabicyclo [5.4.0] undecene-7, and the like. Examples of the imidazole compound include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-ethyl-4-methylimidazole, 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, a phosphorus compound (particularly triphenylphosphine) and an imidazole compound are preferable in that they are more excellent in curability, heat resistance, and electrical properties, and are difficult to reduce moisture reliability.
As for content of a hardening accelerator, 0.1-5 mass% is preferable with respect to an epoxy resin.

Examples of the filler (filler) include crystalline silica powder, fusible silica powder, quartz glass powder, talc, calcium silicate powder, zirconium silicate powder, alumina powder, calcium carbonate powder, and the like. A fusible silica powder is preferred.
Examples of the release agent include various waxes such as carnauba wax.
Examples of the surface treatment agent include known silane coupling agents.
Examples of the colorant include carbon black.
Examples of the flexibility imparting agent include silicone resin and butadiene-acrylonitrile rubber.

  The solvent is not particularly limited as long as it can dissolve an epoxy resin, a curing agent, a curing accelerator, and the like, and a polar solvent is typically used. Examples of polar solvents 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, ethyl diglycol acetate , Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, tetrahydrofuran and the like.

  The epoxy resin composition of this invention can be prepared by mixing an epoxy resin, the hardening | curing agent for epoxy resins of this invention, and another component as needed. Mixing can be performed by a conventional method.

The epoxy resin composition of the present invention has thermosetting properties and can be used as a thermosetting molding material.
There is no restriction | limiting in particular as an application of the epoxy resin composition of this invention, It may be the same as that of the use of a well-known thermosetting molding material. For example, a sealing material, a film material, a laminated material, etc. are mentioned. Among these, from the viewpoint of the usefulness of the present invention, a liquid sealing material is preferable, and an underfill material is particularly preferable.

<Hardened product>
The cured product of the present invention is obtained by curing the epoxy resin composition of the present invention.
Curing of the epoxy resin composition is preferably performed by controlling the temperature at 100 to 200 ° C.
As an example of the curing operation, there may be mentioned a method in which after the curing is carried out at the preferred temperature for 30 seconds to 1 hour, the post-curing is further carried out at the preferred temperature for 1 to 20 hours.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the examples.
In the following examples, “%” indicates “% by mass” unless otherwise specified.
The measurement methods used in the following examples and the test piece production methods are shown below.

[Viscosity of polyvalent hydroxy resin]
It measured with the E-type viscosity meter (made by TOKIMEC) set to 25 degreeC.

[Mass average molecular weight (Mw) and dispersity (Mw / Mn) of polyhydroxy resin]
Using the following GPC apparatus and column, the standard substance was measured as polystyrene.
GPC apparatus: HLC8120GPC manufactured by Tosoh Corporation.
Column: TSKgel G3000HXL + G2000H + G2000H.

[Hydroxyl equivalent of polyvalent hydroxy resin]
Using an automatic titration apparatus (COM-1700S manufactured by Hiranuma Sangyo Co., Ltd.), it was measured by an acetylation method using acetic anhydride.

[Gelification time of epoxy resin composition]
The gelation time was measured at 150 ° C. by a method based on JIS K 6910: 2007.

[Method for producing molded product (cured product)]
The epoxy resin composition is put in a plastic mold, cured at 120 ° C. for 1 hour, the obtained primary cured product is released, and then subjected to a post-curing treatment at 150 ° C. for 1 hour, and a molded product. (Cured product) was obtained.

[Glass transition temperature, storage modulus]
Glass transition temperature (Tg) (° C.), pre-Tg storage elastic modulus (GPa) and post-Tg storage elastic modulus (MPa) of a molded product (width 10.0 mm × length 5.0 mm × thickness 4.0 mm) Using a viscoelastic spectrometer (manufactured by Hitachi High-Tech Science, DMA7100), the measurement was performed at a temperature rising rate of 2 ° C./min in a range of −10 ° C. to 200 ° C.
The storage elastic modulus before Tg is a storage elastic modulus at Tg-25 ° C, and the post-Tg storage elastic modulus is a storage elastic modulus at Tg + 25 ° C.
The glass transition temperature measured by this measurement method was “glass transition temperature: DMA”.

[5% heat reduction temperature]
The thermogravimetric weight loss of the molded product is measured in the air temperature range from 30 ° C to 620 ° C at a heating rate of 10 ° C / min with a differential thermothermogravimetric simultaneous measurement device (TG / DTA6300 manufactured by SII Nanotechnology). The 5% heat reduction temperature (° C.) was determined.

[Glass transition temperature, linear expansion coefficient]
Glass transition temperature (Tg) (° C.), linear expansion coefficient before Tg (α1) and linear expansion coefficient after Tg (α2) of the molded product (width 10.0 mm × length 10.0 mm × thickness 4.0 mm) Was measured in the range of −10 ° C. to 200 ° C. at a temperature increase rate of 2 ° C./min using a thermomechanical analyzer (manufactured by Hitachi High-Tech Science, TMA7100).
The linear expansion coefficient (α1) is a linear expansion coefficient at Tg−20 ° C. to Tg−30 ° C., and the linear expansion coefficient (α2) is a linear expansion coefficient at Tg + 20 ° C. to Tg + 30 ° C.
The glass transition temperature measured by the above measuring method is shown in Table 1 as “glass transition temperature: TMA”.

[Bending elastic modulus]
The flexural modulus (GPa) of the molded product was measured by a method based on JIS K 6911: 1995.

<Example 1>
As a cashew nut shell liquid (CNSL), GOLDEN CASHEW PRODUCTS PVT, trade name: CARDANOL was prepared. This CNSL has a cardanol content of 90.44%, a cardol content of 4.02%, a methyl cardol content of 1.04%, and their total (active ingredient content) is 95.5%. Met.
A 3 L glass flask equipped with a thermometer, stirrer, and condenser is charged with 300 g of CNSL, 150 g of methanol, and 90 g of 50% formaldehyde aqueous solution (1.5 mol, 30% with respect to CNSL). 133 g of an aqueous sodium hydroxide solution was added dropwise at 35 ° C. over 2 hours. Thereafter, CNSL methylolation reaction was carried out at 35 ° C. for 6 hours. Next, 648 g of orthocresol (6 mol, 216% with respect to CNSL) was added, neutralized with 220 g of 30% acetic acid, washed with water, neutralized salts were removed, and 6.49 g of oxalic acid was added. Then, the system was acidified and an addition reaction of orthocresol was performed at 100 ° C. for 4 hours. Subsequently, washing with water was performed, and then excess ortho-cresol was distilled off to obtain a liquid polyvalent hydroxy resin A.
The viscosity of the liquid polyvalent hydroxy resin A at 25 ° C. is 7.8 Pa · s, the mass average molecular weight (Mw) in gel permeation chromatography (GPC) is 1326, the dispersity (Mw / Mn) is 1.514, and the hydroxyl group equivalent Was 206 g / eq. The total content of the structural unit (u2) and the compound (m2) is 80.0% (the balance is 20.0%) with respect to the total mass of the liquid polyvalent hydroxy resin A, and the content of the compound (m2) The amount was 11.2%. These contents were calculated | required by the mass of the liquid polyvalent hydroxy resin A, the amount of CNSL used, and GPC.

<Example 2>
300 g of the same CNSL used in Example 1, 150 g of methanol, 120 g of 50% formaldehyde aqueous solution (2.0 mol, 40% based on CNSL) in a 3 L glass flask equipped with a thermometer, stirrer and condenser Was added dropwise to the mixture over a period of 2 hours at 35 ° C. Thereafter, CNSL methylolation reaction was carried out at 35 ° C. for 6 hours. Next, 648 g (6 mol, 216% based on CNSL) of ortho-cresol was added, washed with water, neutralized salts were removed, 6.49 g of oxalic acid was added to acidify the system, and the mixture was made acidic at 100 ° C. for 4 hours. Then, addition reaction of orthocresol was performed. Subsequently, 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. was 24.4 Pa · s, the mass average molecular weight (Mw) in GPC was 1374, the dispersity (Mw / Mn) was 1.490, and the hydroxyl group equivalent was 201 g / eq. . The total content of the structural unit (u2) and the compound (m2) is 75.5% (the balance is 24.5%) with respect to the total mass of the liquid polyvalent hydroxy resin B, and the content of the compound (m2) The amount was 6.3%. These contents were calculated | required by the mass of the liquid polyvalent hydroxy resin B, the amount of CNSL used, and GPC.

<Example 3>
300 g of the same CNSL used in Example 1, 300 g of phenol, 150 g of methanol, and 120 g of a 50% formaldehyde aqueous solution (2.0 mol, relative to CNSL) were placed in a 3 L glass flask equipped with a thermometer, stirrer, and condenser. 40%), and 133 g of a 30% aqueous sodium hydroxide solution was added dropwise to the mixture at 35 ° C. over 2 hours. Thereafter, CNSL methylolation reaction was carried out at 35 ° C. for 6 hours. Next, 648 g (6 mol, 216% based on CNSL) of ortho-cresol was added, washed with water, neutralized salts were removed, 6.49 g of oxalic acid was added to acidify the system, and the mixture was made acidic at 100 ° C. for 4 hours. Then, addition reaction of orthocresol was performed. Subsequently, 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 25.1 Pa · s, the mass average molecular weight (Mw) in GPC was 1380, the dispersity (Mw / Mn) was 1.492, and the hydroxyl group equivalent was 203 g / eq. . Further, the total content of the structural unit (u2) and the compound (m2) is 75.4% (the balance is 24.6%) with respect to the total mass of the liquid polyvalent hydroxy resin B, and the content of the compound (m2) The amount was 6.6%. These contents were calculated | required by the mass of the liquid polyvalent hydroxy resin C, the amount of CNSL used, and GPC.

<Comparative Example 1: Synthesis of a general low viscosity phenol resin>
In a 2 L glass flask equipped with a thermometer, stirrer and condenser, 941 g (10.0 mol) phenol, 150 g (2.5 mol) 50% aqueous formaldehyde solution, 4.7 g (0.037 mol) oxalic acid ), And the mixture was heated to 100 ° C. and refluxed for 4 hours. Next, washing with water was performed, and then excess phenol was distilled off to obtain a semi-liquid polyvalent hydroxy resin D.
The viscosity of the semi-liquid polyvalent hydroxy resin D at 25 ° C. is too high to be measured (100 Pa · s or more), the mass average molecular weight (Mw) in GPC is 467, and the dispersity (Mw / Mn) is 1. .146, and the hydroxyl equivalent weight was 103 g / eq.

<Comparative Example 2: Synthesis of a general liquid resin using allylphenol>
In a 2 L glass flask equipped with a thermometer, stirrer, and condenser, 1342 g (10.0 mol) of orthoallylphenol, 146.7 g (4.5 mol) of 92% formaldehyde, 13.4 g of oxalic acid (0 .106 mol), the temperature was raised to 120 ° C., and the reaction was carried out for 6 hours. Next, washing with water was performed, and then excess orthoallylphenol was distilled off to obtain a liquid polyvalent hydroxy resin E.
The viscosity of the liquid polyvalent hydroxy resin E at 25 ° C. was 29.1 Pa · s, the mass average molecular weight (Mw) in GPC was 738, the dispersity (Mw / Mn) was 1.371, and the hydroxyl group equivalent was 154 g / eq. .

<Comparative Example 3>
According to Example 1 of Unexamined-Japanese-Patent No. 2015-89940, the liquid polyvalent hydroxy resin F was obtained.
The viscosity at 25 ° C. of the liquid polyvalent hydroxy resin F was 10.2 Pa · s, the mass average molecular weight (Mw) in GPC was 1384, the dispersity (Mw / Mn) was 1.588, and the hydroxyl equivalent was 213 g / eq. . The total content of the structural unit (u2) and the compound (m2) is 66.0% (the balance is 34.0%) with respect to the total mass of the liquid polyvalent hydroxy resin F, and the content of the compound (m2) The amount was 6.5%. These contents were calculated | required by the mass of the liquid polyvalent hydroxy resin F, the amount of CNSL used, and GPC.

<Examples 4-9, Comparative Examples 4-9>
Curing agents, epoxy resins and curing accelerators were mixed in the compositions shown in Tables 1 and 2 to obtain epoxy resin compositions. The compounding amounts of the epoxy resin and the curing agent were set so that the equivalent ratio of the epoxy group in the epoxy resin and the hydroxyl group in the curing agent was 1.
In Tables 1 and 2, the curing agents A to F are respectively the liquid polyvalent hydroxy resin A, the liquid polyvalent hydroxy resin B, the liquid polyvalent hydroxy resin C, the semi-liquid polyvalent hydroxy resin D, and the liquid polyvalent hydroxy resin E. Liquid polyhydroxy resin F.
The epoxy resin 1 is a bisphenol A type liquid epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: Epicoat 828).
The epoxy resin 2 is a bisphenol F type liquid epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: Epicoat 806).
The curing accelerator is 2-ethyl-4-methylimidazole (2E4MZ, reagent, manufactured by Tokyo Chemical Industry Co., Ltd.).
The gelation time of the obtained epoxy resin composition was measured by the above procedure. Moreover, the epoxy resin composition was made into a molded product by the above-described procedure, and the glass transition temperature (TMA, DMA), 5% heat reduction temperature, linear expansion coefficient, storage elastic modulus, and bending elastic modulus were measured. The results are shown in Tables 1-2.

Although the hardening | curing agent D used for the epoxy resin composition of the comparative examples 4 and 7 is a general thing as a phenol type hardening | curing agent, it was high viscosity and exhibited semi-solid form. Moreover, the elasticity modulus of the molding obtained from each epoxy resin composition was high.
The curing agent E used in the epoxy resin compositions of Comparative Examples 5 and 8 is a general liquid resin using allylphenol, which has a lower viscosity than the curing agent D, but the gelation time of the epoxy resin composition. It was longer than Comparative Examples 4 and 7. Moreover, the storage elastic modulus before Tg of the molding obtained from each epoxy resin composition showed the high value equivalent to the comparative examples 4 and 7.
The curing agent F used in the epoxy resin compositions of Comparative Examples 6 and 9 had a low viscosity, but the gelation time of the epoxy resin composition was longer than that of Comparative Examples 5 and 8.
In contrast, the curing agents A to C used in the epoxy resin compositions of Examples 4 to 9 had a lower viscosity than the curing agents D and E. Moreover, the gelation time which is a parameter | index of the hardening rate of each epoxy resin composition was shorter than the comparative examples 6 and 9 using the hardening | curing agent F. Moreover, the elastic modulus (storage elastic modulus and bending elastic modulus) of the molding obtained from each epoxy resin composition was low. Further, the 5% heat reduction temperature was sufficiently high, and it had sufficient heat resistance.

  The liquid polyvalent hydroxy resin of the present invention exhibits a low viscosity liquid at ordinary temperature. Moreover, a low elasticity modulus can be provided to the hardened | cured material of an epoxy resin composition by using the liquid polyvalent hydroxy resin of this invention as a hardening | curing agent for epoxy resins. Therefore, the liquid polyvalent hydroxy resin of the present invention is extremely useful as a highly functional polymer material, and as a material that is physically and electrically superior, a semiconductor sealing material, an underfill material, an electrical insulating material, a copper-clad laminate It can be used for a wide range of applications such as a resin for plates, a resin for conductive pastes, a resin for sealing electronic parts, paints, various coating agents, adhesives, and build-up laminate materials.

Claims (9)

A structural unit represented by the following formula (u1) and a structural unit represented by the following formula (u2);
The total content of the structural unit represented by the formula (u2) and the compound represented by the following formula (m2) is 70 to 90% by mass with respect to the whole liquid polyvalent hydroxy resin,
A liquid polyhydroxy resin having a mass average molecular weight of 800 to 1600.

[Wherein, 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, X is a hydrogen atom or a hydroxyl group, and m and n are respectively Independently 0 or 1, Y is a hydrogen atom or a methyl group. -* Indicates a bond. At least one of the three bonds in formula (u1) is bonded to another structural unit, at least one of the three bonds in formula (u2) is bonded to another structural unit, and the other A bond not bonded to the structural unit is bonded to a hydrogen atom. The benzene ring in each structural unit and the benzene ring in the other structural unit are bonded via a methylene group. ] The liquid polyvalent hydroxy resin of Claim 1 which does not have a structural unit represented by a following formula (u31).

[Wherein R ³ represents an allyl group. ]   The liquid polyvalent hydroxy resin according to claim 1 or 2, wherein the viscosity at 25 ° C is 100 Pa · s or less. It is a manufacturing method of the liquid polyhydric hydroxy resin according to any one of claims 1 to 3,
Reaction of a compound represented by the following formula (m2) and formaldehyde, or a compound represented by the following formula (m1), a compound represented by the above formula (m2) and formaldehyde in the presence of a basic catalyst. And producing a liquid polyvalent hydroxy resin by reacting the reaction product with the compound represented by the formula (m1) in the presence of an acidic catalyst.

[Wherein, 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, X is a hydrogen atom or a hydroxyl group, and Y is a hydrogen atom or It is a methyl group. ] The amount of the reaction in the presence of the basic catalyst of formaldehyde is 10 to 80% by mass with respect to the compound represented by the formula (m2),
The total amount of the compound represented by the formula (m1) to be reacted in the presence of the basic catalyst and the amount to be reacted in the presence of the acidic catalyst is 72 with respect to the compound represented by the formula (m2). The manufacturing method of the liquid polyvalent hydroxy resin of Claim 4 which is -361 mass%.   The hardening | curing agent for epoxy resins which consists of a liquid polyvalent hydroxy resin as described in any one of Claims 1-3.   The epoxy resin composition containing an epoxy resin and the hardening | curing agent for epoxy resins of Claim 6.   A cured product obtained by curing the epoxy resin composition according to claim 7.   The epoxy resin in which at least one part of the hydroxyl group of the liquid polyhydric hydroxy resin as described in any one of Claims 1-3 was epoxidized.