JP6624558B2 - Phenol aralkyl resin, production method thereof, epoxy resin and thermosetting molding material - Google Patents

Description

  The present invention relates to a phenol aralkyl resin, a method for producing the same, an epoxy resin, and a thermosetting molding material.

  Thermosetting molding materials are used for various applications by utilizing their thermosetting properties. For example, in the field of electronic materials, a package that protects a semiconductor element from various external environments (temperature, humidity, stress, and the like) is formed using a thermosetting sealing material. As an encapsulating material, a composition containing an epoxy resin and a curing agent thereof is widely used. As a curing agent for an epoxy resin, a phenolic curing agent is widely used.

  2. Description of the Related Art In recent years, as the processing performance of semiconductor elements has been increased, the integration and performance of semiconductors have been increased, and the demand for reliability of resin materials used therein has become stricter year by year. For example, a semiconductor encapsulating material is required to further improve the low water absorption (low moisture absorption) and heat resistance of the cured product. In response to such demands, for example, a phenol aralkyl resin obtained by reacting phenol with bis (methoxymethyl) biphenyl has been proposed (Patent Document 1).

  As electronic devices become thinner, packages for encapsulating semiconductor elements are becoming thinner year by year. As the package becomes thinner, the method of encapsulating a semiconductor element has shifted from the transfer molding method to a mold underfill method or a compression molding method. Accordingly, there is a demand for a sealing material to be used which has a low viscosity and an improved flowability.

  The phenol aralkyl resin described in Patent Document 1 crystallizes when the softening point and the melt viscosity are lowered to some extent, so that the viscosity cannot be reduced. If the melt viscosity is high, the wire may be broken or deformed when the sealing material is filled. The phenol aralkyl resin has a higher spiral flow than a general phenol resin, but is not sufficient. If the elongation of the spiral flow is not sufficient, the liquid sealing material hardens before the portion to be filled with the sealing material sufficiently spreads, and the sealing may be insufficient.

JP-A-8-143648

  The present invention has been made in view of the above circumstances, and has a low melt viscosity, a long spiral flow of a thermosetting molding material containing the same, a long phenol aralkyl resin, a method for producing the same, and a method using the phenol aralkyl resin. It is an object to provide an epoxy resin and a thermosetting molding material.

The present invention has the following aspects.
(1) A phenol aralkyl resin having a structure in which two or more monohydroxybenzene rings are bonded via a group represented by the following formula (r1) or (r2),
At least a part of the two or more monohydroxybenzene rings has a methyl group as a substituent, and the average number of the methyl groups substituted is 1.5 to 3 per one of the two or more monohydroxybenzene rings. Yes,
A phenol aralkyl resin in which the ratio of the compound represented by the following formula (I) to the entire phenol aralkyl resin, calculated from gel permeation chromatography, is 65 to 95 area%.

[In the formula, n is an integer of 0 to 3, two n may be the same or different, and R ¹ is a group represented by the formula (r1) or (r2). ]

(2) The method for producing a phenol aralkyl resin according to (1),
A phenol (m1) represented by the following formula (m1) and at least one crosslinking agent selected from the group consisting of a compound represented by the following formula (s1) and a compound represented by the following formula (s2): Reacting to obtain a phenol aralkyl resin,
The phenols (m1) include alkylphenols wherein n in the formula (m1) is 2 or 3,
A method for producing a phenol aralkyl resin, wherein the molar ratio of the crosslinking agent / the phenol (m1) is 0.01 to 0.99.

[In the formula, n is an integer of 0 to 3, and X is an alkoxy group having 1 to 4 carbon atoms or a halogen atom. ]

(3) The method for producing a phenol aralkyl resin according to (2), wherein the reaction between the phenol (m1) and the crosslinking agent is performed in the presence of an acidic catalyst.
(4) A thermosetting molding material containing the phenol aralkyl resin according to (1) and an epoxy resin.
(5) An epoxy resin in which at least a part of hydroxyl groups of the phenol aralkyl resin according to (1) is epoxidized.
(6) A thermosetting molding material containing the epoxy resin according to (5) and a curing agent for epoxy resin.
(7) The thermosetting molding material according to (4) or (6), which is a semiconductor sealing material.

  According to the present invention, a phenol aralkyl resin having a low melt viscosity and a long spiral flow of a thermosetting molding material containing the same and a method for producing the same, and an epoxy resin and a thermosetting molding material using the phenol aralkyl resin are provided. Can be provided.

3 is a GPC chart of the phenol aralkyl resin obtained in Example 1. 5 is a GPC chart of the phenol aralkyl resin obtained in Example 2.

<Phenol aralkyl resin>
The phenol aralkyl resin of the present invention has a structure in which two or more monohydroxybenzene rings are bonded via a group represented by the following formula (r1) or (r2). By bonding through a group represented by the formula (r1) or (r2), a cured product of a thermosetting material using a phenol aralkyl resin has excellent properties such as low water absorption and heat resistance.

In the formula (r1), the bonding positions of the two methylene groups in the biphenylene ring are not particularly limited. The crosslinker having this group, which is used at the time of production, is preferably at the 4-position and the 4'-position in that it is relatively inexpensive and has good reactivity with phenols.
In the formula (r2), the bonding positions of the two methylene groups on the benzene ring are not particularly limited. The crosslinking agent having this group, which is used at the time of production, is preferably in the para position because it is relatively inexpensive and has good reactivity with phenols.
In the phenol aralkyl resin, the number of monohydroxybenzene rings bonded via a group represented by the formula (r1) or (r2) is preferably 2 to 30.

In the phenol aralkyl resin of the present invention, at least a part of the two or more monohydroxybenzene rings has a methyl group as a substituent. Having a methyl group as a substituent means that a hydrogen atom bonded to a carbon atom of an unsubstituted monohydroxybenzene ring is substituted with a methyl group.
The number of methyl groups that one monohydroxybenzene ring can have as a substituent is up to three.

In the phenol aralkyl resin of the present invention, the average number of substituted methyl groups is 1.5 to 3 per one or more monohydroxybenzene rings, preferably 2.0 to 2.5, It is particularly preferred that the number be 2.0 to 2.2.
When the average substitution number of the methyl group is equal to or more than the lower limit, the phenol aralkyl resin has low crystallinity and is hardly crystallized even when the molecular weight is reduced for lowering the viscosity. In addition, the reactivity of the hydroxy group bonded to the benzene ring (for example, the reactivity with the epoxy group) is inhibited by the methyl group, so that the gel time of the thermosetting material becomes longer and the spiral flow can be extended.

Since the average number of substituted methyl groups is within the above range, at least a part of the two or more monohydroxybenzene rings has two or three methyl groups as substituents. It is preferable that the number of methyl groups is two in terms of low cost.
Of the total of two or more monohydroxybenzene rings in the phenol aralkyl resin, the proportion of monohydroxybenzene rings having two or three methyl groups as substituents is preferably 50 mol% or more, and is preferably 100 mol% or more. % Is particularly preferred.

The bonding position of the methyl group in the monohydroxybenzene ring is not particularly limited. When the number of methyl groups is 2, the alkylphenols used in the production are relatively inexpensive and have good reactivity with the crosslinking agent. And positions 6 or 2 and 4 are preferred.
The bonding position of the group represented by the formula (r1) or (r2) on the monohydroxybenzene ring is not particularly limited as long as it is a position where a methyl group is not bonded.

  The phenol aralkyl resin of the present invention may have a monohydroxybenzene ring having no methyl group as a substituent. Examples of the monohydroxybenzene ring having no methyl group as a substituent include an unsubstituted monohydroxybenzene ring and a monohydroxybenzene ring having a substituent other than a methyl group as a substituent. Examples of the substituent other than the methyl group include an alkyl group having 2 or more carbon atoms such as an ethyl group and a butyl group, an allyl group, and a methoxy group.

The phenol aralkyl resin of the present invention may or may not have a branch.
For example, in the case of having an unsubstituted monohydroxybenzene ring, the unsubstituted monohydroxybenzene ring has high reactivity at two ortho-positions and one para-position with respect to the position where the hydroxyl group is bonded, and the phenol aralkyl resin Can be a branch point.
Examples of the phenol aralkyl resin having no branch include those represented by the following formula (L).

［式中、ａは０以上の整数（好ましくは０〜２８）であり、ｎは０〜３の整数であり、（ａ＋２）個のｎは同じでも異なってもよく、Ｒ^１は前記式（ｒ１）または（ｒ２）で表される基である。ａが１以上である場合、式中の複数のＲ^１は同じでも異なってもよい。］

[In the formula, a is an integer of 0 or more (preferably 0 to 28), n is an integer of 0 to 3, (a + 2) n may be the same or different, and R ¹ is a group represented by the above formula ( It is a group represented by r1) or (r2). When a is 1 or more, a plurality of R ¹ in the formula may be the same or different. ]

In the phenol aralkyl resin of the present invention, the ratio of the compound represented by the following formula (I) (hereinafter, also referred to as “compound (I)”) to the whole phenol aralkyl resin is 65 to 95 area%, and 70 to 95 area%. It is preferably 95 area%, particularly preferably 75 to 93 area%.
When the proportion of the compound (I) is equal to or more than the above lower limit, the melt viscosity of the phenol aralkyl resin is low, and the reactivity of a hydroxyl group bonded to a benzene ring (for example, the reactivity with an epoxy group) is inhibited by a methyl group. As a result, the gel time of the thermosetting material becomes longer and the spiral flow can be extended.
When the proportion of the compound (I) is equal to or less than the upper limit, the crystallinity of the phenol aralkyl resin can be suppressed, and the compatibility with other materials (such as an epoxy resin) when melt mixed is excellent.
The ratio (area%) of the compound (I) to the whole phenol aralkyl resin is calculated by gel permeation chromatography (hereinafter, also referred to as “GPC”).

［式中、ｎは０〜３の整数であり、２つのｎは同じでも異なってもよく、Ｒ^１は前記式（ｒ１）または（ｒ２）で表される基である。］

[In the formula, n is an integer of 0 to 3, two n may be the same or different, and R ¹ is a group represented by the formula (r1) or (r2). ]

In the formula (I), n is preferably 2 or 3 from the viewpoint of excellent effects of the present invention, and particularly preferably 2 from the viewpoint of low cost.
As the compound (I), R ¹ may include ^one of a compound in which R ¹ is a group represented by the above formula (r1) and a compound in which R ¹ is a group represented by the above (r2), or both. May be.

  In the phenol aralkyl resin of the present invention, three or more monohydroxybenzene rings are bonded via a group represented by the formula (r1) or (r2), and at least a part of the three or more monohydroxybenzene rings. May include a compound having a methyl group as a substituent (hereinafter, also referred to as “compound (II)”).

The phenol aralkyl resin of the present invention preferably has a mass average molecular weight (Mw) of 380 to 1100, more preferably 420 to 810. When Mw is equal to or less than the upper limit, the melt viscosity of the phenol aralkyl resin becomes sufficiently low. When Mw is at least the above lower limit, the crystallinity of the phenol aralkyl resin can be suppressed, and the compatibility at the time of melt mixing is excellent.
The dispersity (Mw / number average molecular weight (Mn)) of the phenol aralkyl resin of the present invention is preferably from 1.00 to 1.50.
In the present invention, Mw and Mn are values measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

The softening point of the phenol aralkyl resin of the present invention is preferably from 50 to 80 ° C, more preferably from 55 to 70 ° C. When the softening point is equal to or higher than the lower limit, the blocking property is good. When the softening point is not more than the above upper limit, the melt viscosity of the phenol aralkyl resin is sufficiently low, and the thermosetting molding material containing the phenol aralkyl resin has high fluidity and can be easily molded.
"Softening point" is measured according to JIS K 6910: 1999.

The melt viscosity at 150 ° C. of the phenol aralkyl resin of the present invention is preferably 2.0 P or less, more preferably 1.5 P or less, and particularly preferably 1.0 P or less. When the melt viscosity is equal to or less than the upper limit, the thermosetting molding material containing the phenol aralkyl resin has high fluidity and is easily molded.
The melt viscosity at 150 ° C. of the phenol aralkyl resin is measured by a melt viscometer (for example, CAP2000 VISCOMMETER manufactured by Brookfield).
The softening point and melt viscosity of the phenol aralkyl resin can be adjusted by the above-mentioned average substitution number of the methyl group, the ratio of the compound (I), the mass average molecular weight (Mw) and the like.

(Method for producing phenol aralkyl resin)
The method for producing the phenol aralkyl resin of the present invention includes, for example, the following production method (P).
Production method (P): at least one selected from the group consisting of a phenol (m1) represented by the following formula (m1), a compound represented by the following formula (s1), and a compound represented by the following formula (s2) Having a step of reacting with one type of crosslinking agent to obtain a phenol aralkyl resin,
The phenols (m1) include alkylphenols wherein n in the formula (m1) is 2 or 3,
A method for producing a phenol aralkyl resin, wherein the molar ratio of the crosslinking agent / the phenol (m1) is 0.01 to 0.99.

［式中、ｎは０〜３の整数であり、Ｘは炭素数１〜４のアルコキシ基またはハロゲン原子である。］

[In the formula, n is an integer of 0 to 3, and X is an alkoxy group having 1 to 4 carbon atoms or a halogen atom. ]

(Phenols (m1))
The phenols (m1) include alkylphenols wherein n in the formula (m1) is 2 or 3.
When n is 2 in the formula (m1), it is xylenol, and examples thereof include 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, and 3,5-xylenol. .
Those in which n is 3 are trimethylphenols, such as 2,3,4-trimethylphenol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, 2,4,5-trimethylphenol, , 4,6-trimethylphenol and the like.
These alkylphenols may be used alone or in combination of two or more.
Among the above-mentioned alkylphenols, 2,6-xylenol and 2,4-xylenol are preferable from the viewpoint that they are relatively inexpensive and have good reactivity with a crosslinking agent.

The phenol (m1) may further include a phenol in which n in the formula (m1) is 0 or 1.
Those in which n is 0 in the formula (m1) are phenol.
The compound in which n in the formula (m1) is 1 is cresol, and examples thereof include orthocresol (2-methylphenol), metacresol (3-methylphenol), and paracresol (4-methylphenol).
These phenols may be used alone or in combination of two or more.

  In the phenols (m1), the content of the alkylphenols in which n is 2 or 3 is preferably 50 mol% or more, more preferably 70 mol% or more, based on the total amount (100 mol%) of the phenols (m1). , 100% is particularly preferred. As the content of the alkylphenols increases, the average number of methyl groups substituted in the phenol aralkyl resin tends to increase.

(Crosslinking agent)
In the formula (s1) or (s2), examples of the halogen atom for X include a chlorine atom and a bromine atom.
As the compound represented by the formula (s1) (hereinafter, also referred to as “compound (s1)”), 4,4′-bis (alkoxymethyl) biphenyl, 2,2′-bis (alkoxymethyl) biphenyl, 2,4'-bis (alkoxymethyl) biphenyl, 4,4'-bis (methyl halide) biphenyl, 2,2'-bis (methyl halide) biphenyl, 2,4'-bis (methyl halide) biphenyl And the like (provided that the alkoxy group has 1 to 4 carbon atoms).
Examples of the compound represented by the formula (s2) (hereinafter, also referred to as “compound (s2)”) include para-xylylene glycol dialkyl ether, meta-xylylene glycol dialkyl ether, 1,4-bis (methyl halide) Benzene and the like (provided that the alkyl group has 1 to 4 carbon atoms).
These crosslinking agents may be used alone or in combination of two or more.
As the crosslinking agent, among the above, from the viewpoint of relatively low cost and good reactivity with alkylphenols, 4,4′-bis (alkoxymethyl) biphenyl and 4,4′-bis (halogenated) Methyl) biphenyl, paraxylylene glycol dialkyl ether, and 1,4-bis (methyl halide) benzene are preferred.

(Reaction between phenols (m1) and crosslinking agent)
The molar ratio of the crosslinking agent / the phenols (m1) is 0.01 to 0.99, and preferably 0.20 to 0.60.
When the ratio of the crosslinking agent to the phenol (m1) is within the above range, the ratio of the compound (I) tends to be within the above range. As the ratio of the crosslinking agent falls within the above range, the ratio of the compound (I) tends to increase.
Further, when the ratio of the crosslinking agent is equal to or more than the above lower limit, the amount of alkylphenols remaining after the reaction decreases, and the yield is good. When the ratio of the crosslinking agent is equal to or less than the above upper limit, the weight average molecular weight becomes small, and the softening point and the melt viscosity become sufficiently low. If the ratio of the cross-linking agent is too low, the yield will be reduced. If the ratio of the cross-linking agent is too high, the softening point or the melt viscosity may increase.

The reaction between the phenol (m1) and the crosslinking agent can be performed in the presence of an acidic catalyst. Thereby, the reaction rate between the phenol (m1) and the crosslinking agent is improved. In particular, when X in the crosslinking agent is an alkoxy group, the reaction is preferably performed in the presence of an acidic catalyst.
When X in the cross-linking agent is a halogen atom, it is not necessary to separately add an acidic catalyst. When X is a halogen atom, the halogen atom is eliminated by heat generated during the reaction to form HX. Since this HX functions as an acidic catalyst, the reaction rate can be sufficiently increased without separately adding an acidic catalyst.

  The acidic catalyst is not particularly limited as long as the reaction proceeds. Examples 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.

The amount of the acidic catalyst to be used is preferably 0.01 to 30% by mass, more preferably 0.5 to 10.0% by mass, based on the phenol (m1).
If the amount of the acidic catalyst medium is too small, the reaction rate is low. If the amount is too large, the reaction proceeds rapidly and it is difficult to control the reaction.

The reaction temperature of the phenol (m1) with the crosslinking agent is preferably from 50 to 250C, more preferably from 100 to 180C. If the reaction temperature is too low, the reaction does not proceed, and if it is too high, it is difficult to control the reaction, and it is difficult to stably obtain the desired phenol aralkyl resin.
At the end of the reaction, an alkali may be added to the obtained reaction product to neutralize the acidic catalyst.

If the average number of methyl groups substituted is 1.5 to 3 and the ratio of the compound (I) is 65 to 95 area%, the obtained reaction product is directly used as the phenol aralkyl resin of the present invention. Can be.
After the reaction of the phenols (m1) with the crosslinking agent, 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.) if necessary. May go.

  In the above production method, a part of the phenol (m1) may be partially substituted with another phenol within a range where the average number of substituted methyl groups is 1.5 to 3 and the ratio of the compound (I) is 65 to 95 area%. May be substituted. Other phenols include, for example, alkyl phenol substituted with an alkyl group having 2 or more carbon atoms, allyl phenol, methoxy phenol and the like. The proportion of other phenols to the total mass of all phenols (total mass of phenols (m1) and other phenols) is preferably 10% by mass or less, particularly preferably 0% by mass.

(Use of phenol aralkyl resin)
The use of the phenol aralkyl resin of the present invention is not particularly limited, and the phenol aralkyl resin can be used for various applications known as uses of the phenol resin.
For example, since the phenol aralkyl resin of the present invention has a plurality of hydroxyl groups, it is used as 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. be able to. The phenol aralkyl resin of the present invention is suitable as a curing agent for epoxy resins.
Further, the phenol aralkyl resin of the present invention can be used as a material for producing an epoxy resin. For example, an epoxy resin can be obtained by epoxidizing a hydroxyl group of a phenol aralkyl resin.

(Effect)
In the phenol aralkyl resin of the present invention, the average number of substitution of the methyl group is 1.5 to 3 per one or more of the monohydroxybenzene rings, and the ratio of the compound (I) is 65. When it is で あ 95 area%, the melt viscosity at 150 ° C. is low. Further, by using the phenol aralkyl resin of the present invention, a thermosetting molding material having a long gel time can be obtained. In addition, the cured product of the thermosetting molding material has low water absorption because the group bonding two or more monohydroxybenzene rings of the phenol aralkyl resin is the group represented by the formula (r1) or (r2). Excellent physical properties such as heat resistance.

<Epoxy resin>
The epoxy resin of the present invention is obtained by epoxidizing at least a part of the hydroxyl groups of the phenol aralkyl resin of the present invention.
Epoxidation of a hydroxyl group can be performed by a known method. For example, by reacting a phenol aralkyl resin with epichlorohydrin, some or all of the hydroxyl groups of the phenol aralkyl resin (such as the hydroxyl group of a monohydroxybenzene ring) are -OX (where X is a glycidyl group). An epoxy resin having the following structure can be obtained.

<Thermosetting molding material (1)>
The thermosetting molding material of the first aspect of the present invention (hereinafter, also referred to as “thermosetting molding material (1)”) contains an epoxy resin and the phenol aralkyl resin of the present invention.
The thermosetting molding material (1) may further contain other components other than the epoxy resin and the phenol aralkyl resin of the present invention, if necessary.
The thermosetting molding material (1) may contain a solvent as needed. When the thermosetting molding material (1) is used as a semiconductor encapsulating material, it is preferable not to contain a solvent.

The epoxy resin is not particularly limited and may be a known epoxy resin, for example, a phenol novolak type epoxy resin, an orthocresol novolak 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, Examples include a phosphorus atom-containing epoxy resin.
As the epoxy resin, the epoxy resin of the present invention (an epoxy resin in which at least a part of hydroxyl groups of a phenol aralkyl resin is epoxidized) may be used.
One of these epoxy resins may be used alone, or two or more may be used in combination.

  In the thermosetting molding material (1), the content of the phenol aralkyl resin of the present invention is such that the equivalent ratio (epoxy group / hydroxyl group) of the epoxy group of the epoxy resin to the hydroxyl group of the phenol aralkyl resin of the present invention is 0.90. It is preferable that the amount is １．１1.10. The epoxy group / hydroxyl group is more preferably from 0.98 to 1.02. When the epoxy group / hydroxyl group is within the above range, the obtained cured product has good heat resistance and water absorption.

As the other components, curing agents for epoxy resins other than the phenol aralkyl resin of the present invention (hereinafter also referred to as other curing agents), curing accelerators, fillers (fillers), release agents, surface treatment agents, Coloring agents, flexibility-imparting agents and the like.
As other curing agents, those conventionally known as curing agents used for epoxy resins can be used. For example, phenol novolak resin, triphenylmethane type phenol resin, xylylene type phenol resin, biphenylene type phenol resin, dicyclopentadiene Examples include phenol resins such as type phenol resins, acid anhydrides, and amine resins.

The curing accelerator is not particularly limited, and may be a known curing accelerator. Examples 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. As the tertiary amine, 2-dimethylaminomethylphenol, benzyldimethylamine, α-methylbenzylmethylamine, 1,8-diazabicyclo [5.4.0] undecene-7,1,8-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. One of these curing accelerators may be used alone, or two or more of them may be used in combination.
The content of the curing accelerator is preferably from 0.5 to 5.0% by mass based on the 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. Fusing 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 coloring agent include carbon black.
Examples of the flexibility imparting agent include silicone resin, butadiene-acrylonitrile rubber, and the like.

  The solvent is not particularly limited as long as it dissolves an epoxy resin, a phenol aralkyl resin, a curing accelerator and 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 acetate. Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, tetrahydrofuran and the like.

  The thermosetting molding material (1) can be prepared by mixing an epoxy resin, the phenol aralkyl resin of the present invention, and, if necessary, other components. Mixing can be performed by a conventional method.

The thermosetting molding material (1) can be cured by heating.
The curing of the thermosetting molding material (1) is preferably performed while controlling the temperature to 80 to 120 ° C.
As an example of the curing operation, a method of once performing the melt mixing for 300 seconds or more and 600 seconds or less at the above-mentioned suitable temperature, and further performing the post-curing at 150 to 220 ° C. for 1 to 5 hours is exemplified.

  The use of the thermosetting molding material (1) is not particularly limited, and may be the same as the use of a known thermosetting molding material. For example, a sealing material, a film material, a laminated material, and the like can be given. Among them, a semiconductor encapsulating material is preferable from the viewpoint of the usefulness of the present invention.

<Thermosetting molding material (2)>
The thermosetting molding material (hereinafter, also referred to as “thermosetting material (2)”) according to the second aspect of the present invention includes the epoxy resin of the present invention (at least a part of the hydroxyl group of the phenol aralkyl resin of the present invention). Epoxidized) and a curing agent for epoxy resin.
The thermosetting molding material (2) may further contain components other than the epoxy resin of the present invention and a curing agent for epoxy resin, if necessary.
The thermosetting molding material (2) may contain a solvent, if necessary. When the thermosetting molding material (2) is used as a semiconductor encapsulating material, it is preferable not to contain a solvent.

As the curing agent for the epoxy resin, a conventionally known curing agent used for the epoxy resin can be used. For example, a functional group that reacts with an epoxy group such as a hydroxyl group, an acid anhydride group and an amino group (hereinafter referred to as “reactive A compound having two or more functional groups). Specific examples include phenol resins such as phenol novolak resins, triphenylmethane-type phenol resins, xylylene-type phenol resins, biphenylene-type phenol resins, and dicyclopentadiene-type phenol resins, acid anhydrides, and amine resins.
The phenol aralkyl resin of the present invention may be used as a curing agent for an epoxy resin.
One of these curing agents for epoxy resins may be used alone, or two or more thereof may be used in combination.

  In the thermosetting molding material (2), the content of the epoxy resin curing agent is determined by the equivalent ratio of the epoxy group of the epoxy resin of the present invention to the reactive functional group of the epoxy resin curing agent (epoxy group / reactivity (Functional group) is preferably 0.90 to 1.10. The epoxy group / reactive functional group is more preferably from 0.98 to 1.02. When the epoxy group / reactive functional group is in the above range, the cured product obtained has good heat resistance and moisture resistance.

As the other components, epoxy resins other than the epoxy resin of the present invention (hereinafter also referred to as other epoxy resins), curing accelerators, fillers (fillers), release agents, surface treatment agents, coloring agents, And a flexibility imparting agent.
As other epoxy resins, the same epoxy resins as those described for the thermosetting molding material (1) can be used. The curing accelerator, the filler, the release agent, the surface treatment agent, the coloring agent, the flexibility imparting agent, and the solvent are the same as those described for the thermosetting molding material (1).

  The thermosetting molding material (2) can be prepared by mixing the epoxy resin of the present invention, a curing agent for epoxy resin, and, if necessary, other components. Mixing can be performed by a conventional method.

The thermosetting molding material (2) can be cured by heating.
The curing of the thermosetting molding material (2) is preferably performed while controlling the temperature to 80 to 120 ° C.
As an example of the curing operation, a method of once performing the melt mixing for 300 seconds or more and 600 seconds or less at the above-mentioned suitable temperature, and further performing the post-curing at 150 to 220 ° C. for 1 to 5 hours is exemplified.

  The use of the thermosetting molding material (2) is not particularly limited, and may be the same as the use of a known thermosetting molding material. For example, a sealing material, a film material, a laminated material, and the like can be given. Among them, a semiconductor encapsulating material is preferable from the viewpoint of the usefulness of the present invention.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples. Example 5 described below is a reference example.
In each of the following examples, “%” indicates “% by mass” unless otherwise specified.
The measurement method used in each of the following examples is shown below.

[Softening point of resin]
The softening point was measured according to JIS K 6910: 1999.

[Melting viscosity of resin]
The melt viscosity at 150 ° C. was measured by a melt viscometer (CAP2000 VISCOMMETER manufactured by Brookfield) set at 150 ° C.

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

[Ratio of compound (I) in resin (area%)]
GPC was performed using the above-described GPC apparatus and column, and the peak area ratio of compound (I) to the entire resin (100 area%) was determined from the obtained GPC chart.
The peak of compound (I) was confirmed by nuclear magnetic resonance analysis (NMR) and mass spectrometry (MS).

[Gel time of thermosetting molding material]
After the thermosetting molding material was pulverized finely, 0.5 g was weighed, melted on a hot plate at 175 ° C., and the time (sec) until gelation while stirring was measured.

[Fluidity of thermosetting molding material (spiral flow)]
The fluidity (spiral flow) of the thermosetting molding material is determined by transferring the thermosetting molding material to a mold for flow measurement at 175 ° C for 120 seconds, and melting the thermosetting molding material (before curing). The flow length (cm) that has flowed from the start to the hardening is used as an index. The longer the flow length, the higher the flowability, and the easier it is to mold.

[Glass transition temperature of molded product (cured product)]
The thermosetting molding material was transfer-molded at 175 ° C. for 120 seconds to prepare a test piece (2 mm wide × 30 mm long × 1 mm thick), which was post-cured at 180 ° C. for 5 hours.
The glass transition temperature of the post-cured test piece was measured using a viscoelastic spectrometer (manufactured by Seiko Instruments, DMS 110) at a rate of 10 ° C./min in the range of 30 ° C. to 300 ° C.

[5% thermal decomposition temperature of molded product (cured product)]
The thermosetting molding material was transfer-molded at 175 ° C. for 120 seconds to prepare a test piece (2 mm wide × 30 mm long × 1 mm thick), which was post-cured at 180 ° C. for 5 hours.
The thermogravimetric weight loss of the post-cured test piece was measured in an air atmosphere by a differential thermogravimetric simultaneous measurement device (TG / DTA6300 manufactured by Seiko Instruments Inc.), and a 5% thermal decomposition temperature (° C.) was determined.

[Water absorption of molded product (cured product)]
The thermosetting molding material was cured at 180 ° C. for 5 hours to prepare a disk-shaped test piece (diameter 50 mm, thickness 3 mm) for evaluating water absorption. The prepared test piece and pure water (20 mL) were placed in a pressure cooker and placed in a 121 ° C. oven for 20 hours. Thereafter, the mass of the test piece was measured, and the water absorption was calculated by the following equation.
Water absorption = (mass after 20 hours in oven-mass before oven) / mass before oven × 100

<Example 1>
(Reaction of 2,6-xylenol with bis (methoxymethyl) biphenyl (molar ratio = 0.2))
244 g (2.0 mol) of 2,6-xylenol and 1.2 g of paratoluenesulfonic acid (0.2 g for 2,6-xylenol) were placed in a pressure-resistant reaction vessel having a capacity of 1 L equipped with a thermometer, a stirrer, and a condenser. 5% by mass), the temperature was raised to 150 ° C., and 96.8 g (0.4 mol) of bis (methoxymethyl) biphenyl was added dropwise over 5 hours. Thereafter, aging was performed at 150 ° C. for 1 hour, and the temperature was increased to 170 ° C., and aging was performed for 1 hour. Methanol by-produced in the reaction was removed out of the system. After completion of the reaction, neutralization and washing were performed, and residual 2,6-xylenol was removed by distillation to obtain a phenol aralkyl resin.
The softening point of the obtained resin was 63 ° C, and the melt viscosity at 150 ° C was 0.3P. The weight average molecular weight (Mw) by GPC was 743, the degree of dispersion (Mw / Mn) was 1.21, and the ratio of the compound (I) was 80.1 area%. The GPC chart is shown in FIG.
Table 1 shows the molar ratio of the crosslinking agent / phenols, the properties of the obtained resin, and the crystallinity at the time of taking out (the presence or absence of crystallization at the time of removing the unreacted monomer) (the same applies hereinafter).

(Preparation and evaluation of thermosetting molding material)
Using the obtained resin as a curing agent, a thermosetting molding material was prepared according to the formulation shown in Table 2, and the gel time, fluidity (spiral flow), glass transition temperature of the molded product, 5% thermal decomposition temperature and water absorption The rate was measured. Table 2 shows the results.

<Example 2>
(Reaction of 2,6-xylenol with bis (methoxymethyl) biphenyl (molar ratio = 0.05))
244 g (2.0 mol) of 2,6-xylenol and 1.2 g of paratoluenesulfonic acid (0.2 g for 2,6-xylenol) were placed in a pressure-resistant reaction vessel having a capacity of 1 L equipped with a thermometer, a stirrer, and a condenser. 5% by mass), the temperature was raised to 150 ° C., and 24.2 g (0.1 mol) of bis (methoxymethyl) biphenyl was added dropwise over 5 hours. Thereafter, aging was performed at 150 ° C. for 1 hour, and the temperature was increased to 170 ° C., and aging was performed for 1 hour. Methanol by-produced in the reaction was removed out of the system. After completion of the reaction, neutralization and washing were performed, and residual 2,6-xylenol was removed by distillation to obtain a phenol aralkyl resin.
The obtained resin had a softening point of 56 ° C. and a melt viscosity at 150 ° C. of 0.2P. The weight average molecular weight (Mw) by GPC was 581, the degree of dispersion (Mw / Mn) was 1.04, and the ratio of the compound (I) was 93.5 area%. FIG. 2 shows the GPC chart.

(Preparation and evaluation of thermosetting molding material)
Using the obtained resin as a curing agent, a thermosetting molding material was prepared according to the formulation shown in Table 2, and the gel time, fluidity (spiral flow), glass transition temperature of the molded product, 5% thermal decomposition temperature and water absorption The rate was measured. Table 2 shows the results.

<Example 3>
(Reaction of 2,4-xylenol with bis (methoxymethyl) biphenyl (molar ratio = 0.2))
244 g (2.0 mol) of 2,4-xylenol and 1.2 g of paratoluenesulfonic acid (0.2 g to 2,4-xylenol) were placed in a 1 L internal pressure-resistant reaction vessel equipped with a thermometer, a stirrer, and a condenser. 5% by mass), the temperature was raised to 150 ° C., and 96.8 g (0.4 mol) of bis (methoxymethyl) biphenyl was added dropwise over 5 hours. Thereafter, aging was performed at 150 ° C. for 1 hour, and the temperature was increased to 170 ° C., and aging was performed for 1 hour. Methanol by-produced in the reaction was removed out of the system. After completion of the reaction, neutralization and washing were performed, and residual 2,4-xylenol was removed by distillation to obtain a phenol aralkyl resin.
The softening point of the obtained resin was 61 ° C, and the melt viscosity at 150 ° C was 0.3P. The weight average molecular weight (Mw) by GPC was 702, the degree of dispersion (Mw / Mn) was 1.17, and the ratio of the compound (I) was 81.9 area%.

(Preparation and evaluation of thermosetting molding material)
Using the obtained resin as a curing agent, a thermosetting molding material was prepared according to the formulation shown in Table 2, and the gel time, fluidity (spiral flow), glass transition temperature of the molded product, 5% thermal decomposition temperature and water absorption The rate was measured. Table 2 shows the results.

<Example 4>
(Reaction of 2,4-xylenol with bis (methoxymethyl) biphenyl (molar ratio = 0.05))
244 g (2.0 mol) of 2,4-xylenol and 1.2 g of paratoluenesulfonic acid (0.2 g to 2,4-xylenol) were placed in a 1 L internal pressure-resistant reaction vessel equipped with a thermometer, a stirrer, and a condenser. 5% by mass), the temperature was raised to 150 ° C., and 24.2 g (0.1 mol) of bis (methoxymethyl) biphenyl was added dropwise over 5 hours. Thereafter, aging was performed at 150 ° C. for 1 hour, and the temperature was increased to 170 ° C., and aging was performed for 1 hour. Methanol by-produced in the reaction was removed out of the system. After completion of the reaction, neutralization and washing were performed, and residual 2,4-xylenol was removed by distillation to obtain a phenol aralkyl resin.
The obtained resin had a softening point of 54 ° C. and a melt viscosity at 150 ° C. of 0.2P. The weight average molecular weight (Mw) by GPC was 564, the degree of dispersion (Mw / Mn) was 1.04, and the ratio of the compound (I) was 93.7 area%.

(Preparation and evaluation of thermosetting molding material)
Using the obtained resin as a curing agent, a thermosetting molding material was prepared according to the formulation shown in Table 2, and the gel time, fluidity (spiral flow), glass transition temperature of the molded product, 5% thermal decomposition temperature and water absorption The rate was measured. Table 2 shows the results.

<Example 5>
(Reaction of 2,6-xylenol with para-xylene glycol dimethyl ether (molar ratio = 0.2))
244 g (2.0 mol) of 2,6-xylenol and 1.2 g of para-toluenesulfonic acid (0,0 to 2,6-xylenol) were placed in a pressure-resistant reaction vessel having a capacity of 1 L equipped with a thermometer, a stirrer, and a cooling tube. The mixture was heated to 150 ° C., and 66.4 g (0.4 mol) of para-xylene glycol dimethyl ether was added dropwise over 5 hours. Thereafter, aging was performed at 150 ° C. for 1 hour, and the temperature was increased to 170 ° C., and aging was performed for 1 hour. Methanol by-produced in the reaction was removed out of the system. After completion of the reaction, neutralization and washing were performed, and residual 2,6-xylenol was removed by distillation to obtain a phenol aralkyl resin.
The softening point of the obtained resin was 57 ° C., and the melt viscosity at 150 ° C. was 0.3P. The weight average molecular weight (Mw) by GPC was 701, the degree of dispersion (Mw / Mn) was 1.18, and the ratio of the compound (I) was 77.9 area%.

(Preparation and evaluation of thermosetting molding material)
Using the obtained resin as a curing agent, a thermosetting molding material was prepared according to the formulation shown in Table 2, and the gel time, fluidity (spiral flow), glass transition temperature of the molded product, 5% thermal decomposition temperature and water absorption The rate was measured. Table 2 shows the results.

<Comparative Example 1>
(Reaction between phenol and bis (methoxymethyl) biphenyl)
Phenol (564 g, 6.0 mol) and bis (methoxymethyl) biphenyl (242 g, 1.0 mol) were placed in a 1-L glass flask equipped with a thermometer, a stirrer, and a condenser. 0.9 g (0.15% by mass based on phenol) was added and reacted at 150 ° C. for 3 hours. The methanol generated at this time was removed out of the system. After completion of the reaction, the mixture was neutralized and washed with water, and unreacted monomer (phenol) was removed by distillation to obtain a phenol aralkyl resin.
The obtained resin crystallized in the removal step, and the softening point and the melt viscosity could not be measured. Therefore, preparation and evaluation of the thermosetting molding material were not performed.

<Comparative Example 2>
(Reaction between phenol and para-xylene glycol dimethyl ether)
Phenol 211.5 g (2.25 mol) and 166 g (1.0 mol) of para-xylene glycol dimethyl ether were placed in a 1-L glass flask equipped with a thermometer, a stirrer, and a cooling tube. 0.4 g was added and reacted at 150 ° C. for 3 hours. The methanol generated at this time was removed out of the system. After completion of the reaction, the mixture was cooled to 95 ° C. and neutralized with a 48% KOH aqueous solution. After removing unreacted monomers, the resultant was washed with water to obtain a phenol aralkyl resin. The obtained resin had a softening point of 71 ° C. and a melt viscosity of 1.8 P. The weight average molecular weight (Mw) by GPC was 801 and the degree of dispersion (Mw / Mn) was 1.53.

(Preparation and evaluation of thermosetting molding material)
Using the obtained resin as a curing agent, a thermosetting molding material was prepared according to the formulation shown in Table 2, and the gel time, fluidity (spiral flow), glass transition temperature of the molded product, 5% thermal decomposition temperature and water absorption The rate was measured. Table 2 shows the results.

<Comparative Example 3>
(Reaction between phenol and bis (methoxymethyl) biphenyl)
Phenol (376 g, 4.0 mol) and bis (methoxymethyl) biphenyl (242 g, 1.0 mol) were placed in a 1-L glass flask equipped with a thermometer, a stirrer, and a cooling tube. 0.6 g was added and reacted at 150 ° C. for 3 hours. The methanol generated at this time was removed out of the system. After completion of the reaction, the mixture was cooled to 95 ° C. and neutralized with a 48% KOH aqueous solution. After removing the unreacted monomer, the resultant was washed with water to obtain a phenol aralkyl resin. The obtained resin had a softening point of 69 ° C. and a melt viscosity of 0.9P. The weight average molecular weight (Mw) by GPC was 616, and the degree of dispersion (Mw / Mn) was 1.23.

(Preparation and evaluation of thermosetting molding material)
Using the obtained resin as a curing agent, a thermosetting molding material was prepared according to the formulation shown in Table 2, and the gel time, fluidity (spiral flow), glass transition temperature of the molded product, 5% thermal decomposition temperature and water absorption The rate was measured. Table 2 shows the results.

<Comparative Example 4: Reaction of 2,6-xylenol with bis (methoxymethyl) biphenyl (molar ratio = 0.5)>
244 g (2.0 mol) of 2,6-xylenol and 4.9 g of paratoluenesulfonic acid (2 parts per 2,6-xylenol) were placed in a 1-L pressure-resistant reaction vessel equipped with a thermometer, a stirrer, and a condenser. % By mass), the temperature was raised to 150 ° C., and 242 g (1.0 mol) of bis (methoxymethyl) biphenyl was added dropwise over 5 hours. Thereafter, aging was performed at 150 ° C. for 1 hour, and the temperature was increased to 170 ° C., and aging was performed for 1 hour. Methanol by-produced in the reaction was removed out of the system. After the completion of the reaction, the residual 2,6-xylenol was 13%. Thereafter, the mixture was neutralized and washed with water, and the remaining 2,6-xylenol was removed by distillation to obtain a phenol aralkyl resin.
The obtained resin had a softening point of 85 ° C and a melt viscosity at 150 ° C of 2.7P. The mass average molecular weight (Mw) by GPC was 1,677, the degree of dispersion (Mw / Mn) was 1.59, and the ratio of the compound (I) was 58.8 area%. The yield with respect to the charged 2,6-xylenol was 157%. Due to the high melt viscosity, no thermosetting molding material was prepared and evaluated.

<Comparative Example 5: Reaction of 2,6-xylenol with para-xylene glycol dimethyl ether (molar ratio = 0.5)>
244 g (2.0 mol) of 2,6-xylenol and 4.9 g of paratoluenesulfonic acid (2 parts per 2,6-xylenol) were placed in a 1-L pressure-resistant reaction vessel equipped with a thermometer, a stirrer, and a condenser. % By mass) and heated to 150 ° C., and 166 g (1.0 mol) of paraxylene glycol dimethyl ether was added dropwise over 5 hours. Thereafter, aging was performed at 150 ° C. for 1 hour, and the temperature was increased to 170 ° C., and aging was performed for 1 hour. Methanol by-produced in the reaction was removed out of the system. The residual 2,6-xylenol after the completion of the reaction was 15%. Thereafter, neutralization and washing were performed, and unreacted 2,6-xylenol was removed by distillation to obtain a phenol aralkyl resin. The softening point of the obtained resin was 80 ° C., and the melt viscosity at 150 ° C. was 2.4P. The weight average molecular weight (Mw) by GPC was 1,561, the degree of dispersion (Mw / Mn) was 1.55, and the ratio of the compound (I) was 57.1 area%. The yield with respect to the charged 2,6-xylenol was 127%. Due to the high melt viscosity, no thermosetting molding material was prepared and evaluated.

In Table 2, the unit of the amount of each component is g (gram).
As the epoxy resin, a phenol biphenylene type epoxy resin (NC3000H manufactured by Nippon Kayaku) was used.
The blending amount of the spherical silica was set such that the ratio of the spherical silica to the total amount of the thermosetting molding material was 83%. The blending amount of triphenylphosphine (curing accelerator) was set to be 2% with respect to the epoxy resin. The blending amount of carnauba wax was set to be 1% based on the total mass of the thermosetting molding material.

As shown in Table 1, the melt viscosity of the phenol aralkyl resins of Examples 1 to 5 at 150 ° C. Lower than Comparative Example 3 which is a phenol biphenyl resin.
Also, as shown in Table 2, the thermosetting molding materials using the phenol aralkyl resins of Examples 1 to 5 had longer gel times and longer spiral flows than Comparative Examples 2 and 3. Further, molded products of these thermosetting molding materials had sufficient heat resistance and low water absorption.
In Comparative Example 1 in which the proportion of the crosslinking agent was reduced compared to Comparative Example 3 in order to reduce the viscosity of the phenol biphenyl resin, the obtained resin crystallized in the removal step.
The phenol aralkyl resins of Comparative Examples 4 to 5 in which the ratio of the compound (I) was less than 65 area% had a high melt viscosity at 150 ° C.

  The phenol aralkyl resin of the present invention has a low melt viscosity. The thermosetting molding material containing the phenol aralkyl resin of the present invention has a long gel time and a long spiral flow. A cured product of the thermosetting molding material has high heat resistance and low water absorption. Therefore, the phenol aralkyl resin and the thermosetting molding material of the present invention are extremely useful as a high-performance polymer material, and as a thermally and electrically excellent material, a semiconductor sealing material, an electrically insulating material, a copper-clad laminate It can be used for a wide range of applications such as board resins, resists, sealing resins for electronic components, color filter resins for liquid crystals, paints, various coating agents, adhesives, build-up laminate materials, and FRP.

Claims (7)

A phenol aralkyl resin having a structure in which two or more monohydroxybenzene rings are bonded via a group represented by the following formula (r1 ) ,
At least a part of the two or more monohydroxybenzene rings has a methyl group as a substituent, and the average substitution number of the methyl group is 1.5 to 2.5 per one of the two or more monohydroxybenzene rings. Wherein the monohydroxybenzene ring having a methyl group includes a monohydroxybenzene ring having a methyl group at the 2-position and the 6-position, or the 2-position and the 4-position with respect to the position where the hydroxyl group is bonded,
A phenol aralkyl resin in which the ratio of the compound represented by the following formula (I) to the entire phenol aralkyl resin, calculated from gel permeation chromatography, is 65 to 95 area%.

[In the formula, n is an integer of 0 to 3, two n's may be the same or different, and R ¹ is a group represented by the formula (r1 ) . ] A method for producing a phenol aralkyl resin according to claim 1,
Phenols represented by the following formula (m1) and (m1), comprising the step of obtaining a phenol aralkyl resin by reacting a cross-linking agent you express by the following formula (s1),
The phenols (m1) include one or both of 2,6-xylenol and 2,4-xylenol ;
A method for producing a phenol aralkyl resin, wherein the molar ratio of the crosslinking agent / the phenol (m1) is 0.01 to 0.99.

[In the formula, n is an integer of 0 to 3, and X is an alkoxy group having 1 to 4 carbon atoms or a halogen atom. ]   The method for producing a phenol aralkyl resin according to claim 2, wherein the reaction between the phenol (m1) and the crosslinking agent is performed in the presence of an acidic catalyst.   A thermosetting molding material containing an epoxy resin and the phenol aralkyl resin according to claim 1.   An epoxy resin in which at least a part of hydroxyl groups of the phenol aralkyl resin according to claim 1 is epoxidized.   A thermosetting molding material containing the epoxy resin according to claim 5 and a curing agent for an epoxy resin.   7. The thermosetting molding material according to claim 4, which is a semiconductor sealing material.

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