WO2015080059A1 - Liquid epoxy resin composition - Google Patents

Abstract

Provided is a low-viscosity liquid epoxy resin composition from which a cured product with excellent heat resistance can be obtained. This liquid epoxy resin composition is characterized by containing (A) a glycidyl ether compound and (B) a phenolic resin curing agent, and in that the glycidyl ether compound (A) is liquid at 25°C and contains substantially no carbon-chlorine bonds, and the phenolic resin curing agent (B) is solid at 25°C.

Description

Liquid epoxy resin composition

The present invention relates to a liquid epoxy resin composition. More specifically, the present invention relates to a low-viscosity liquid epoxy resin composition containing a glycidyl ether compound and a phenolic curing agent.

Epoxy resins have excellent physical properties such as electrical insulation, heat resistance, moisture resistance, and dimensional stability, so that they can be used for conductive materials such as semiconductor encapsulants, printed circuit boards, build-up boards, electronic components such as resist ink, and conductive paste. Wide range of adhesives and other adhesives, liquid sealing materials such as underfill, liquid crystal sealing materials, flexible substrate coverlays, build-up adhesive films, composite matrixes, paints, photoresist materials, developer materials, etc. It is used. Among these, in the field of electronic materials such as semiconductors and printed wiring boards, demands for higher performance of sealing materials, board materials, etc. are increasing with technological innovation in these fields.

For example, resins used for liquid sealing materials such as underfill materials are required to have a low viscosity for the purpose of enhancing the filling property of fine parts as equipment is miniaturized and highly integrated. In addition, in semiconductor encapsulants and conductive adhesives, the viscosity of resin compositions will be lowered for the purpose of improving heat resistance and dimensional stability by increasing the amount of filler, or reducing resistance by increasing the filling of conductive filler. The demand for is great. In these applications, since high heat resistance is also an essential condition, the resin needs to satisfy both heat resistance and low viscosity.

For reducing the viscosity of the resin composition, a method of adding a low molecular weight epoxy compound as a reactive diluent is common. However, in the method of adding a monofunctional or bifunctional epoxy compound, the crosslink density of the resin is lowered, and thus the heat resistance of the cured product is greatly lowered. On the other hand, a trifunctional or higher functional epoxy compound has a wide molecular weight distribution and a large number of functional groups because the ring-opening addition product produced by the reaction between the polyhydric alcohol and epichlorohydrin used as a raw material during synthesis is easily polymerized. Nevertheless, it is known that the glass transition temperature of the cured product is significantly reduced.

On the other hand, as an epoxy resin curing agent, various compounds such as amine compounds, phenol resins, acid anhydrides, imidazole compounds, and thiol compounds can be used. In general, acid anhydrides, amine compounds, Alternatively, an imidazole compound is used as a curing agent. Phenol resin curing agents have a characteristic of giving a cured product with a high glass transition point reflecting a rigid resin skeleton, but many of them are solid at room temperature and are therefore often handled without solvent. The example used for a conductive adhesive and an underfill agent has been limited.

Recently, phenolic resins that are liquid at room temperature by introducing a substituent such as an allyl group onto the aromatic ring of the phenolic resin have been reported (for example, Patent Documents 1 and 2). However, when a liquid phenolic resin is used as a curing agent, since the resin has a high degree of freedom (providing flexibility to the molecule) in the resin, a rigid resin skeleton that generally contributes to high heat resistance is included. Nevertheless, the glass transition temperature of the cured product is low. Therefore, when used as a semiconductor sealing material, underfill material, conductive adhesive, etc. used under high temperature conditions, it is considered that the reliability is poor. Patent Document 3 discloses a side reaction by epoxidizing a carbon-carbon double bond of a compound having three or more carbon-carbon double bonds in the molecule by an oxidation reaction using hydrogen peroxide as an oxidizing agent. It is disclosed that a liquid epoxy resin composition having a low total chlorine content can be obtained while an increase in the molecular weight distribution due to the production of a high molecular weight product is suppressed. However, there is no description or suggestion that a liquid curable composition having excellent heat resistance can be obtained by using a solid phenol resin as a curing agent at room temperature.

JP 10-168283 A JP 2000-169537 A JP 2013-189504 A

In view of the above problems, an object of the present invention is to provide a low-viscosity liquid epoxy resin composition from which a cured product having excellent heat resistance can be obtained.

According to the previous study by the present applicant, the conventional carbon-carbon double bond of a compound having a carbon-carbon double bond in the molecule is epoxidized by an oxidation reaction using hydrogen peroxide as an oxidizing agent. High-purity liquid epoxy compound with low molecular weight distribution and low total chlorine content due to high molecular weight generation due to side reaction such as reaction product of polyhydric alcohol and epichlorohydrin Is found to be obtained. The epoxy compound thus obtained exhibits the characteristics that it has a low viscosity at room temperature compared to conventional products and gives a cured product having a high glass transition temperature.

Based on these studies, the present inventors have conducted further studies to solve the above problems, and as a result, epoxidize the carbon-carbon double bond of a compound having a carbon-carbon double bond in the molecule. The low-viscosity glycidyl ether compound obtained in 1) has excellent heat resistance derived from the glycidyl ether and the solid phenol resin curing agent despite the low viscosity at room temperature by dissolving the solid phenol resin as a curing agent. The inventors have found that a liquid epoxy resin composition can be obtained, and have completed the present invention.

That is, the present invention includes the following embodiments.
[1] A liquid epoxy resin composition comprising (A) a glycidyl ether compound and (B) a phenol resin-based curing agent, wherein the (A) glycidyl ether compound is a liquid at 25 ° C. and has a carbon-chlorine bond And (B) the phenol resin-based curing agent is solid at 25 ° C.
[2] The liquid epoxy resin composition according to [1], which does not contain a solvent and a reactive diluent.
[3] The liquid epoxy resin composition according to either [1] or [2], further comprising (C) a curing accelerator.
[4] The liquid epoxy resin composition according to any one of [1] to [3], wherein the (A) glycidyl ether compound is a polyhydric glycidyl ether of an aliphatic polyhydric alcohol having 3 to 30 carbon atoms.
[5] The glycidyl ether compound (A) is obtained by reacting the carbon-carbon double bond of the allyl group of the allyl ether compound with an oxidizing agent. Liquid epoxy resin composition.
[6] The liquid epoxy resin composition according to any one of [1] to [5], wherein the viscosity of the (A) glycidyl ether compound at 25 ° C. is 1 mPa · s to 1000 mPa · s.
[7] The (A) glycidyl ether compound is 1,4-cyclohexanedimethanol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether, ditrimethylolpropane tetraglycidyl ether, diglycerin. The liquid epoxy resin composition according to any one of [1] to [6], comprising at least one selected from the group consisting of tetraglycidyl ether, dipentaerythritol hexaglycidyl ether, and sorbitol hexaglycidyl ether.
[8] The (B) phenol resin-based curing agent includes at least one selected from the group consisting of a phenol novolak resin, a cresol novolak resin, a triphenylmethane type phenol resin, and a dicyclopentadiene-modified phenol resin. [1] The liquid epoxy resin composition according to any one of [7] to [7].
[9] The liquid epoxy resin according to any one of [1] to [8], comprising 20 to 300 parts by mass of the (B) phenol resin-based curing agent with respect to 100 parts by mass of the (A) glycidyl ether compound. Composition.
[10] The curing accelerator (C) is at least one selected from the group consisting of imidazole compounds and derivatives thereof, phosphine compounds and derivatives thereof, and tertiary amines and derivatives thereof. ] The liquid epoxy resin composition in any one of.
[11] The amount of the (C) curing accelerator is 0.1 to 10 parts by mass with respect to a total of 100 parts by mass of the (A) glycidyl ether compound and the (B) phenol resin curing agent. 10] The liquid epoxy resin composition according to any one of [10].

Since the liquid epoxy resin composition of the present invention contains a solid (B) phenol resin curing agent, the cured product can have a high glass transition temperature (Tg). In addition, the liquid (A) glycidyl ether compound not containing a high molecular weight component has a low viscosity and excellent compatibility with the solid (B) phenol resin curing agent, and it is possible to use no solvent and / or reactive diluent. A low-viscosity liquid epoxy resin composition can be prepared. As a result, the liquid epoxy resin composition of the present invention is excellent in fluidity even when the filler is highly filled and a cured product having a high glass transition temperature can be obtained. It is particularly useful for liquid sealing materials such as underfill materials and conductive adhesives.

In the total ion chromatogram and chromatogram obtained by gas chromatography / mass spectrometry (GC / MS) of 1,4-cyclohexanedimethanol diglycidyl ether (CDMDG) obtained in Production Example 2 used in Examples It is a figure which shows the mass spectrum in the peak 1. The mass spectrum at peak 1 in the total ion chromatogram and chromatogram obtained by gas chromatography / mass spectrometry (GC / MS) of glycerin triglycidyl ether (GLYG) obtained in Production Example 3 used in the Examples is shown. FIG. The total ion chromatogram obtained by size exclusion chromatography / mass spectrometry (SEC / MS) of the pentaerythritol tetraglycidyl ether (PETG) obtained in Production Example 4 and the fractions in the chromatogram used in the examples 1 to 4 (fraction 1: retention time 11-12 minutes, fraction 2: retention time 12-13 minutes, fraction 3: retention time 13-14 minutes, fraction 4: retention time 14-15 minutes) FIG. Total ion chromatogram obtained by size exclusion chromatography / mass spectrometry (SEC / MS) of commercially available pentaerythritol polyglycidyl ether (Denacol (registered trademark) EX-411) used in Comparative Example 2 and fractions in the chromatogram Mass in 1-4 (fraction 1: retention time 11-12 minutes, fraction 2: retention time 12-13 minutes, fraction 3: retention time 13-14 minutes, fraction 4: retention time 14-15 minutes) It is a figure which shows a spectrum. FIG. 3 is a view showing molecular weight distributions of phenol resin-based curing agents (B-1) to (B-4) used in Examples.

Hereinafter, the present invention will be described in detail.
The liquid epoxy resin composition of the present invention comprises (A) a glycidyl ether compound and (B) a phenol resin-based curing agent, and (A) the glycidyl ether compound is liquid at 25 ° C. and has substantially no carbon-chlorine bond. And (B) the phenol resin-based curing agent is solid at 25 ° C.

(A) Glycidyl ether compound The glycidyl ether compound contained in the liquid epoxy resin composition of the present invention is a compound which is essentially liquid at 25 ° C. and does not contain a carbon-chlorine bond in the molecule. The glycidyl ether compound used in the conventional epoxy resin composition is mainly produced by a condensation reaction of an aliphatic alcohol or phenol and epichlorohydrin, and at that time, it is represented by the formula (1) in the molecule. A compound having a terminal group containing a carbon-chlorine bond is produced as a by-product. The separation and removal of these by-products are very laborious and extremely difficult to remove completely. When a glycidyl ether compound mixed with by-products is used, the viscosity of the resin composition increases, and the obtained cured product has a low glass transition temperature and poor heat resistance.

In the present invention, “substantially free of carbon-chlorine bond” means that no peak corresponding to the compound containing carbon-chlorine bond and a fragment thereof is observed in the mass spectrum of the glycidyl ether compound. More specifically, in the mass spectrum of a glycidyl ether compound, a peak corresponding to a compound containing a carbon-chlorine bond and a fragment thereof produced as a by-product when producing a glycidyl ether compound by an epichlorohydrin method using an aliphatic alcohol as a raw material. Means not allowed.

Examples of the method for producing the glycidyl ether compound that does not generate the by-product used in the present invention include a method of oxidizing the carbon-carbon double bond of the allyl group of the allyl ether compound with an oxidizing agent, and more specifically. For example, it can be produced by the following method.
1) A method for oxidizing a carbon-carbon double bond of an allyl ether compound using a peracid (such as peracetic acid) as an oxidizing agent (for example, JP-A-7-145221)
2) A method of oxidizing a carbon-carbon double bond of an allyl ether compound using hydrogen peroxide (more specifically, an aqueous hydrogen peroxide solution) as an oxidizing agent and using a catalyst such as tungsten or zeolite (for example, JP-A-60). -60123)
3) A method in which the carbon-carbon double bond of an allyl ether compound is oxidized in a basic atmosphere in the presence of acetonitrile using hydrogen peroxide (more specifically, an aqueous hydrogen peroxide solution) as an oxidizing agent (for example, Japanese Patent Laid-Open No. Sho 59). No. 227872)

The glycidyl ether compound obtained by the above method is preferably used after purification by distillation, adsorbent treatment or the like, if necessary.

The glycidyl ether compound used in the present invention is liquid at 25 ° C. The viscosity of the glycidyl ether compound at 25 ° C. is preferably in the range of 1 mPa · s to 1000 mPa · s. In some preferred embodiments, the viscosity at 25 ° C. of the glycidyl ether compound is 5 mPa · s or more, or 10 mPa · s or more, 500 mPa · s or less, or 300 mPa · s or less. The epoxy equivalent of the glycidyl ether compound is preferably in the range of 80 to 300 g / equivalent, more preferably in the range of 90 to 200 g / equivalent. When the epoxy equivalent is less than 80 g / equivalent, the impact resistance of the cured product is reduced. On the other hand, when it exceeds 300 g / equivalent, the viscosity when the curing agent is added becomes very high, and the handleability deteriorates.

The glycidyl ether compound used in the present invention preferably has an average of two or more glycidyl groups in one molecule in order to exhibit good mechanical strength as a cured product. Among them, polyhydric allyl ethers of aliphatic polyhydric alcohols having 3 to 30 carbon atoms (in which at least two hydroxyl groups of polyhydric alcohols are substituted with allyloxy groups, some hydroxyl groups remain. It is particularly preferable to use a polyhydric glycidyl ether of an aliphatic polyhydric alcohol having 3 to 30 carbon atoms, obtained by epoxidizing a carbon-carbon double bond (including those) with an oxidizing agent.

Specifically, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,8-octanediol diglycidyl ether, 1,9-nonanediol diglycidyl ether, 1,10-decane Diol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, tricyclodecane dimethanol diglycidyl ether , Hydrogenated bisphenol A diglycidyl ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, pentaerythritol Laglycidyl ether, ditrimethylolpropane tetraglycidyl ether, diglycerin tetraglycidyl ether, erythritol tetraglycidyl ether, xylitol pentaglycidyl ether, dipentaerythritol pentaglycidyl ether, dipentaerythritol hexaglycidyl ether, sorbitol hexaglycidyl ether, inositol pentaglycidyl ether And inositol hexaglycidyl ether. Among these, in consideration of the viscosity of the compound and the heat resistance of the cured product, 1,4-cyclohexanedimethanol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether, ditrimethylol Propane tetraglycidyl ether, diglycerin tetraglycidyl ether, dipentaerythritol hexaglycidyl ether, and sorbitol hexaglycidyl ether are preferred, 1,4-cyclohexanedimethanol diglycidyl ether, tricyclodecane dimethanol diglycidyl ether, trimethylolpropane tri Glycidyl ether, glycerin triglycidyl ether, and pentaerythritol tetraglycidyl ether Preferred.

(B) Phenolic resin-based curing agent The liquid epoxy resin composition of the present invention contains (B) a phenolic resin-based curing agent for reacting with the (A) glycidyl ether compound to form a cured product. The (B) phenol resin-based curing agent used in the present invention is solid at 25 ° C. Since the resin has high rigidity as compared with the case of using a liquid phenol-based curing agent, it is possible to obtain a cured product having a high glass transition temperature by restricting free rotation of molecules.

As the phenol resin-based curing agent, a compound having two or more phenolic hydroxyl groups in one molecule is used. Specific examples include bisphenol A, bisphenol F, phenol novolak resin, cresol novolak resin, triphenylmethane type phenol resin, dicyclopentadiene modified phenol resin, phenol aralkyl resin, zyloc type phenol resin, terpene type phenol resin and the like. The Among these, a phenol novolak resin, a cresol novolak resin, a triphenylmethane type phenol resin, and a dicyclopentadiene-modified phenol resin are particularly preferable in view of compatibility with glycidyl ether and heat resistance. These may be used alone or in combination of two or more. Since these phenol resin-based curing agents have good compatibility with the above-mentioned glycidyl ether compound, they can be dissolved uniformly without using a solvent and / or a reactive diluent to obtain a liquid curable composition.

The blending amount of the phenol resin curing agent in the liquid epoxy resin composition of the present invention varies depending on the hydroxyl equivalent of the phenol resin curing agent and the epoxy equivalent of the glycidyl ether compound to be used, but with respect to 100 parts by mass of the glycidyl ether compound. In view of the viscosity of the resin composition and the heat resistance of the cured product, it is preferable to add the phenol resin-based curing agent in a proportion of 20 to 300 parts by mass. The blending amount of the phenol resin-based curing agent is more preferably 40 to 200 parts by mass, and further preferably 50 to 150 parts by mass with respect to 100 parts by mass of the glycidyl ether compound.

(C) Curing accelerator A curing accelerator can be blended in the liquid epoxy resin composition of the present invention, if necessary, in order to obtain appropriate curability. This curing accelerator is not particularly limited as long as it can be used as a curing accelerator for epoxy resins, and known ones can be used, but imidazole-based, phosphine-based, or tertiary amine-based curing accelerators can be used. Is preferably used.

Specifically, examples of the imidazole curing accelerator include imidazole compounds and derivatives thereof such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2- Examples include phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and epoxy-imidazole adduct. Examples of phosphine curing accelerators include phosphine compounds and derivatives thereof such as triphenylphosphine, triparatolylphosphine, tricyclohexylphosphine, 1,4-bisdiphenylphosphinobutane, tetraphenylphosphonium tetraphenylborate, triphenylphosphinetriphenylborane. And tetraphenylphosphonium tetra-p-tolylborate. Tertiary amine curing accelerators include tertiary amines and derivatives thereof such as 1,8-diazabicyclo [5,4,0] undecene-7 (DBU), 1,5-diazabicyclo [4,3,0] nonene. -5 (DBN), DBU phenol salt, DBU octylate, DBU p-toluenesulfonate, DBU phenol novolac resin salt, DBN (diazabicyclononene) phenol novolac resin salt, DBU derivative tetra Examples thereof include phenyl borate, triethylenediamine, benzyldimethylamine, and triethanolamine.

The amount of the curing accelerator used may vary depending on the type of phenol resin-based curing agent and curing accelerator used. It is preferably used at a ratio of 10 parts by mass.

In addition, in the liquid epoxy resin composition of the present invention, a filler (eg, silica, alumina, boron nitride, aluminum nitride, etc.), a colorant (eg, Carbon black, dyes, etc.), flame retardants, ion trapping agents, antifoaming agents, leveling agents and the like may be included. Further, a silane coupling agent may be contained in order to improve the adhesion to the substrate. Specific examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyl (methyl) dimethoxysilane, 2- (2,3-epoxycyclohexyl) ethyltrimethoxysilane, 3-methacryl Examples include oxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3- (2-aminoethyl) aminopropyltrimethoxysilane.

The method for preparing the liquid epoxy resin composition of the present invention is not particularly limited, and each component is charged at a predetermined blending ratio into a mixing machine such as a likai machine, a pot mill, a three roll mill, a rotary mixer, a twin screw mixer, Can be prepared by mixing.

The viscosity of the liquid epoxy resin composition of the present invention is not particularly limited, and may be in various viscosity ranges depending on the type of glycidyl ether compound and phenol resin-based curing agent to be used. The viscosity is preferably 2000 Pa · s or less. When the resin composition contains a filler, the viscosity of the resin composition before filling the filler is preferably in the range of 0.1 Pa · s to 1000 Pa · s from the viewpoint of improving the filling amount of the filler and preventing sedimentation. If the viscosity is too low, the filler is liable to settle and the dispersion state may be non-uniform. If it is too high, it is difficult to increase the filling amount of the filler. The viscosity of the resin composition before filling the filler is more preferably in the range of 1 Pa · s to 500 Pa · s, and still more preferably in the range of 5 Pa · s to 250 Pa · s.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

<Measurement of epoxy equivalent>
The epoxy equivalent is determined according to JIS-K7236. A sample is weighed 0.1 to 0.2 g and placed in an Erlenmeyer flask, and then 10 mL of dichloromethane is added and dissolved. Next, 20 mL of acetic acid is added, followed by 10 mL of tetraethylammonium bromide solution (100 g of tetraethylammonium bromide dissolved in 400 mL of acetic acid). One or two drops of crystal violet indicator are added to this solution, titrated with a 0.1 mol / L perchloric acid acetic acid solution, and an epoxy equivalent is determined according to the following formula based on the titration result.
Epoxy equivalent (g / eq) = (1000 × m) / {(V1−V0) × c}
m: Mass of the sample (g)
V0: Amount of perchloric acid acetic acid solution consumed for titration to the end point in the blank test (mL)
V1: Amount of perchloric acid acetic acid solution consumed for titration to the end point (mL)
c: Concentration of perchloric acid acetic acid solution (0.1 mol / L)

<Measurement of viscosity>
The viscosities of the glycidyl ether compound and the liquid epoxy resin composition are measured using a cone plate viscometer RVDV-II + Pro manufactured by Brookfield. After 0.5 mL of the sample is placed on the sample stage, it is sandwiched between cone plates (diameter 48 mm or 24 mm, cone angle 3 °), and the viscosity is measured under the conditions of measurement temperature: 25 ° C. and rotation speed: 1 rpm. A sample with a viscosity of 1 mPa · s to 1 Pa · s uses a cone plate with a diameter of 48 mm, and a sample with a viscosity of 1 Pa · s to 2000 Pa · s uses a cone plate with a diameter of 24 mm.

<Measurement of total chlorine content>
The total amount of chlorine is measured by burning and decomposing a sample at a high temperature of 800 ° C. or higher, absorbing the decomposed gas in ultrapure water, etc., and quantifying it by ion chromatography. The ion chromatography is composed of 861 Advanced Compact IC, Shodex SI-90 4E column manufactured by Metrohm, and is measured at a flow rate of 1.3 mL / min using 1.7 mM NaHCO ₃ /1.8 mM Na ₂ CO ₃ aqueous solution as an eluent. .

<Measurement of mass spectrum>
<GC / MS measurement>
Gas chromatography / mass spectrometry (GC / MS) by chemical ionization (CI) method is performed under the following conditions.
Apparatus: 7890A (GC part, manufactured by Agilent Technologies, Inc.) / JEOL JMS-Q1000GC MkII (MS part, manufactured by JEOL Ltd.)
Column: Agilent HP-5 (inner diameter 0.32 mm; length 30 m; film thickness 0.25 μm)
Column oven temperature: 50 ° C. (3 min) → [20 ° C./min]→320° C. (10 min)
Carrier gas: He
Column flow rate: 1.5 mL / min (constant flow mode)
Injection mode: Split (1:20)
Inlet temperature: 300 ° C
Injection volume: 1 μL (using an autosampler)
Transfer line temperature: 300 ° C
Ionization method: CI (chemical ionization method)
CI reaction gas: isobutane scan range: m / z 60-600
Sample preparation: 50 mg / mL (solvent is acetone)

<SEC / MS measurement>
Size exclusion chromatography / mass spectrometry (SEC / MS) by atmospheric pressure chemical ionization (APCI) method is performed under the following conditions.
1) SEC (size exclusion chromatography) section column: ShodexGPC KF-402 × 2
Column temperature: 40 ° C
Eluent: Tetrahydrofuran (HPLC grade), 0.3 mL / min
2) MS (mass spectrometry) part ionization method: atmospheric pressure chemical ionization method (+)
Scan range: m / z 50-2000

[Production Example 1: Synthesis of polyvalent allyl ether]
Various polyvalent allyl ethers used in Production Examples 2 to 4 described later were synthesized based on Williamson synthesis. As an example, a synthesis method of 1,4-cyclohexanedimethanol diallyl ether is described below.

Into a 2 liter three-necked flask equipped with a stirrer and a thermometer, 144.2 g (1.00 mol) of 1,4-cyclohexanedimethanol (manufactured by Shin Nippon Rika Co., Ltd.) was placed, the inside of the reactor system was purged with nitrogen, 480.0 g (6.0 mol) of an aqueous sodium oxide solution (50% by mass) was added, heated to 40 ° C., and 3.224 g (0.01 mol) of tetrabutylammonium bromide (manufactured by Wako Pure Chemical Industries, Ltd.) was added. . While maintaining the inside of the reaction system at about 40 ° C., 168.3 g (2.20 mol) of allyl chloride (manufactured by Kashima Chemical Co., Ltd.) was added dropwise, and after 2 hours, 72.11 g of 1,4-cyclohexanedimethanol (0. 50 mol) and 84.17 g (1.10 mol) of allyl chloride were added. Thereafter, the reaction was continued while gradually raising the reaction temperature, and 25.25 g (0.33 mol) of allyl chloride was added by observing the progress of the reaction to complete the reaction. After completion of the reaction, 33.7 g of toluene was added to carry out a liquid separation treatment, and the organic layer was washed with pure water 200 mL / times until neutral, and after the liquid separation, the organic layer was evaporated to remove the solvent, allyl chloride, and the like by an evaporator. . After the solvent was distilled off, 1,4-cyclohexanedimethanol diallyl ether was obtained by precision distillation (distillation temperature: 63.9 to 67.7 ° C. (11 Pa)).

Other polyvalent allyl ethers were also synthesized according to the above procedure.

[Production Example 2: Synthesis of 1,4-cyclohexanedimethanol diglycidyl ether (CDMDG)]
1,4-cyclohexanedimethanol diallyl ether (100 g, 0.45 mol), acetonitrile (73.2 g, 1.78 mol, manufactured by Junsei Co., Ltd.), methanol (92.9 g, 2. 90 mol, Junsei Chemical Co., Ltd.) was weighed into a 500 mL 3-diameter eggplant type flask. The temperature in the system was set to 35 ° C. using a water bath, and the pH was reached to 10.5 with a saturated aqueous potassium hydroxide solution (KOH / H ₂ O = 110 g / 100 mL). Until the end of the reaction, a saturated aqueous potassium hydroxide solution was added as needed so that the reaction temperature did not exceed 40 ° C., and the pH was controlled in the range of 10.75 to 10.25. A 45% aqueous hydrogen peroxide solution (81.6 g, 1.08 mol, manufactured by Nippon Peroxide Co., Ltd.) was added dropwise over a period of 16 hours using a 300 mL dropping funnel, and the mixture was further stirred for 10 hours to complete the reaction. When the reaction solution was measured by gas chromatography, the conversion rate of cyclohexanedimethanol diallyl ether as a substrate was 100%, the yield of cyclohexanedimethanol diglycidyl ether as diepoxy was 88.5%, monoepoxy It was confirmed that the yield of monoglycidyl ether was 2.6%.

The obtained reaction solution was distilled at a vacuum degree of 13 kPa, a flask temperature of 265 ° C., and a column temperature of 190 ° C. using a precision distillation apparatus manufactured by Daishin Kogyo Co., Ltd., so that the purity by gas chromatography was 99.5%. 1,4-cyclohexanedimethanol diglycidyl ether (CDMDG) was obtained. The viscosity of CDMDG was 34 mPa · s, and the epoxy equivalent determined by titration was 136. The total chlorine content was 5 ppm, and it was confirmed from GC / MS analysis results (FIG. 1) that no organic chlorine was contained (the contained chlorine was not derived from a compound having a carbon-chlorine bond).

[Production Example 3: Synthesis of glycerin triglycidyl ether (GLYG)]
Glycerol triallyl ether (50 g, 0.24 mol), acetonitrile (77 g, 1.9 mol, manufactured by Junsei Co., Ltd.), methanol (91 g, 2.8 mol, Junsei Chemical) obtained by synthesis in the same manner as in Production Example 1 above. Co., Ltd.) was charged into a 500 mL four-necked flask, and a small amount of 50% by mass aqueous potassium hydroxide solution was added to adjust the pH of the reaction solution to about 10.5. Until the end of the reaction, a saturated aqueous potassium hydroxide solution was added as needed so that the reaction temperature did not exceed 40 ° C., and the pH was controlled in the range of 10.75 to 10.25. A 35% by mass aqueous hydrogen peroxide solution (82 g, 0.8 mol, manufactured by Nippon Peroxide Co., Ltd.) was added dropwise over 9 hours, and the mixture was further stirred for 16 hours. Then, 1 g of sodium sulfite was added to the reaction solution to stop the reaction. After the solvent was distilled off using a diaphragm pump, 500 g of ethyl acetate and 300 g of a 10% by mass sodium sulfate aqueous solution were added to separate the aqueous layer and the organic layer. Thereafter, the organic layer was washed 5 times with 20 g of pure water to remove residual impurities such as sodium sulfite and by-product acetamide, and then the solvent was distilled off to obtain glycerin at a purity of 91%, a yield of 36 g, and a yield of 59%. Triglycidyl ether (GLYG) was obtained. The viscosity of GLYG was 32 mPa · s, and the epoxy equivalent determined by titration was 91. The total chlorine content was 112 ppm, and it was confirmed from GC / MS analysis results (FIG. 2) that no organic chlorine was contained (the contained chlorine was not derived from a compound having a carbon-chlorine bond).

[Production Example 4: Synthesis of pentaerythritol tetraglycidyl ether (PETG)]
Pentaerythritol tetraallyl ether (200 g, 0.67 mol), acetonitrile (220 g, 5.36 mol, manufactured by Junsei Chemical Co., Ltd.), methanol (100 g, 3.12 mol, genuine) obtained by synthesis in the same manner as in Production Example 1 above. Chemical Co., Ltd.) was charged into a 2 liter three-necked flask, and a small amount of 50% by mass potassium hydroxide aqueous solution (Wako Pure Chemical Industries, Ltd.) was added to adjust the pH in the reaction system to about 10.5. Until the end of the reaction, a saturated aqueous potassium hydroxide solution was added as needed so that the reaction temperature did not exceed 40 ° C., and the pH was controlled in the range of 10.75 to 10.25. A 45 mass% aqueous hydrogen peroxide solution (160 g, 2.12 mol, manufactured by Nippon Peroxide Co., Ltd.) was added dropwise over 18 hours. To the reaction solution, 2.11 g of sodium sulfite (manufactured by Wako Pure Chemical Industries, Ltd.) and 1000 g of toluene were added to temporarily stop the reaction, followed by stirring at room temperature for 30 minutes to separate an aqueous layer and an organic layer. Thereafter, the organic layer was washed twice with 150 g of pure water, and the solvent was distilled off to obtain a reaction mixture.

Thereafter, acetonitrile (220 g, 5.36 mol) and methanol (100 g, 3.12 mol) were added to the reaction mixture, and a small amount of 50% by mass aqueous potassium hydroxide was added to adjust the pH of the reaction solution to about 10.5. A 45 mass% hydrogen peroxide aqueous solution (125 g, 1.65 mol) was added dropwise at a temperature of 35 ° C over 28 hours so that the internal temperature did not exceed 45 ° C. After completion of the dropwise addition, 15.9 g of sodium sulfite and 800 g of toluene were added to stop the reaction, and the mixture was stirred at room temperature for 30 minutes to separate the aqueous layer and the organic layer. Thereafter, the organic layer was washed twice with 150 g of pure water to remove residual impurities such as sodium sulfite and by-product acetamide, and the solvent was distilled off to obtain a purity of 90%, a yield of 176.04 g, and a yield of 72.4. % Pentaerythritol tetraglycidyl ether (PETG) was obtained. The viscosity of PETG was 166 mPa · s, and the epoxy equivalent determined by titration was 98. The total chlorine amount was 636 ppm, and it was confirmed from the SEC / MS analysis results (FIG. 3) that no organic chlorine was contained (the contained chlorine was not derived from a compound having a carbon-chlorine bond).

[Preparation of liquid resin composition]
The liquid epoxy resin compositions of Examples 1 to 21 and Comparative Examples 1 to 2 were prepared by mixing and dissolving each component using a 50 ° C. ultrasonic water bath with the formulation shown in Tables 1 to 4. Each component used for preparation of the liquid epoxy resin composition in a table | surface is shown below.
(A) Glycidyl ether compound (A-1) 1,4-cyclohexanedimethanol diglycidyl ether obtained in Production Example 2 (CDMDG, total chlorine amount 5 ppm, viscosity 34 mPa · s)
(A-2) Glycerin triglycidyl ether obtained in Production Example 3 (GLYG, total chlorine amount 112 ppm, viscosity 32 mPa · s)
(A-3) Pentaerythritol tetraglycidyl ether obtained in Production Example 4 (PETG, total chlorine amount 636 ppm, viscosity 166 mPa · s)
(A-4) Commercially available pentaerythritol polyglycidyl ether manufactured by epichlorohydrin method (manufactured by Nagase ChemteX Corporation, Denacol (registered trademark) EX-411, viscosity 819 mPa · s, epoxy equivalent 233, total chlorine content 16.8% , SEC / MS analysis result (Figure 4) has carbon-chlorine bond in the molecule)
(B) Phenol resin-based curing agent (B-1) Phenol novolac resin (Showa Denko KK, Shonor (registered trademark) BRG-556, softening point 77 to 83 ° C.)
(B-2) Phenol novolak resin (manufactured by Showa Denko KK, Shonor (registered trademark) BRG-564G, softening point 60 ° C.)
(B-3) Phenol novolak resin (manufactured by Showa Denko KK, Shonor (registered trademark) BRG-555, softening point 67-72 ° C.)
(B-4) Phenol novolac resin (manufactured by Showa Denko KK, Shonor (registered trademark) BRG-558, softening point 93 to 98 ° C.)
(B-5) Triphenylmethane type phenolic resin (manufactured by Showa Denko KK, Shonor (registered trademark) TRI-220, softening point 83 ° C.)
(B-6) Liquid phenol novolac resin (manufactured by Showa Denko KK, patent document: synthesized based on the method disclosed in JP2012-67253A)
At 25 ° C., (B-1) to (B-5) are all solid, and (B-6) is liquid. The molecular weight distributions of (B-1) to (B-4) are shown in FIG.
(C) Curing accelerator (C-1) 2-ethyl-4-methylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd., Curesol (registered trademark) 2E4MZ)
(C-2) Triphenylphosphine (made by Hokuko Chemical Co., Ltd.)

[Production and property evaluation of cured products]
The resin compositions prepared in Examples 1-21 and Comparative Examples 1-2 were each vacuum degassed, then poured into a mold capable of producing a cured product having a thickness of 3 mm, and heated in an oven at 150 ° C. for 30 minutes. To obtain a cured plate. The following measurements were performed using the obtained cured plate. The obtained physical property values are shown in Tables 1 to 4.

<Glass transition temperature (Tg)>
Measured by thermomechanical measurement (TMA). Using a TMA / SS6100 thermomechanical analyzer manufactured by SII Nano Technology, Inc., a 10 × 10 × 3 mm test piece under the conditions of a temperature range of −10 to 250 ° C., a heating rate of 5 ° C./min, and a load of 20.0 mN Use to measure. The temperature at the intersection of two extrapolated lines drawn in the linear region before and after the inflection point based on the transition in the obtained expansion curve is defined as the glass transition temperature.

<Linear expansion coefficient (CTE)>
Similarly to Tg, the linear expansion coefficient is determined from the expansion coefficient in the Z-axis (thickness) direction as measured by TMA. In the obtained expansion curve, α ₁ is in the range of (Tg−40 ° C.) to (Tg−20 ° C.), and α ₂ is in the range of (Tg + 20 ° C.) to (Tg + 40 ° C.) as the average value of the linear portion before and after Tg. Ask for each.

As shown in Tables 1 to 4, the liquids of Examples 1 to 21 using the glycidyl ether compounds synthesized in Production Examples 2 to 4 and solid phenol resin curing agents (B-1) to (B-5) were used. The epoxy resin composition was obtained by using the same glycidyl ether compound as the liquid epoxy resin composition of Comparative Example 1 using the glycidyl ether compound synthesized in Production Example 2 and the liquid phenol resin (B-6). In comparison, the glass transition temperature (Tg) of the resulting cured product showed a significantly large value. Examples 12 to 17 using pentaerythritol tetraglycidyl ether (A-3) synthesized in Production Example 4 are comparative examples using pentaerythritol polyglycidyl ether (A-4) containing a commercially available high molecular weight component. Compared with 2, the Tg of the obtained cured product showed a significantly large value. Further, when Example 16 and Comparative Example 2 having relatively close compositions are compared, Example 16 has a lower viscosity than Comparative Example 2, and Example 16 contains more additive. It is suggested to be advantageous.

From the above results, it is suggested that the cured product of the liquid epoxy resin composition of the present invention is superior in heat resistance as compared with the cured product of the resin composition using the conventional liquid phenolic curing agent.

The liquid epoxy resin composition of the present invention has a low viscosity and its cured product has excellent heat resistance, and is particularly useful for liquid sealing materials such as semiconductor sealing materials and underfill materials, and conductive adhesive applications. is there.

Claims (11)

A liquid epoxy resin composition comprising (A) a glycidyl ether compound and (B) a phenolic resin-based curing agent, wherein the (A) glycidyl ether compound is liquid at 25 ° C. and has substantially no carbon-chlorine bond. And the (B) phenol resin-based curing agent is solid at 25 ° C. The liquid epoxy resin composition according to claim 1, which does not contain a solvent and a reactive diluent. The liquid epoxy resin composition according to claim 1, further comprising (C) a curing accelerator. The liquid epoxy resin composition according to any one of claims 1 to 3, wherein the (A) glycidyl ether compound is a polyhydric glycidyl ether of an aliphatic polyhydric alcohol having 3 to 30 carbon atoms. The liquid epoxy resin according to any one of claims 1 to 4, wherein the (A) glycidyl ether compound is obtained by reacting an allyl group carbon-carbon double bond of an allyl ether compound with an oxidizing agent. Composition. 6. The liquid epoxy resin composition according to claim 1, wherein the viscosity of the (A) glycidyl ether compound at 25 ° C. is 1 mPa · s to 1000 mPa · s. The (A) glycidyl ether compound is 1,4-cyclohexanedimethanol diglycidyl ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether, ditrimethylolpropane tetraglycidyl ether, diglycerin tetraglycidyl ether. The liquid epoxy resin composition according to any one of claims 1 to 6, comprising at least one selected from the group consisting of: dipentaerythritol hexaglycidyl ether, and sorbitol hexaglycidyl ether. The (B) phenol resin-based curing agent includes at least one selected from the group consisting of a phenol novolak resin, a cresol novolak resin, a triphenylmethane type phenol resin, and a dicyclopentadiene-modified phenol resin. 8. The liquid epoxy resin composition according to any one of 7 above. The liquid epoxy resin composition according to any one of claims 1 to 8, comprising 20 to 300 parts by mass of the (B) phenol resin-based curing agent with respect to 100 parts by mass of the (A) glycidyl ether compound. 10. The curing accelerator (C) is at least one selected from the group consisting of imidazole compounds and derivatives thereof, phosphine compounds and derivatives thereof, and tertiary amines and derivatives thereof. The liquid epoxy resin composition according to item. 11. The composition according to claim 3, comprising 0.1 to 10 parts by mass of the (C) curing accelerator with respect to 100 parts by mass in total of the (A) glycidyl ether compound and (B) a phenol resin curing agent. The liquid epoxy resin composition according to one item.

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