JP2020147726A - Epoxy resin composition, epoxy resin cured product and epoxy resin modifier - Google Patents

Abstract

To provide a novel epoxy resin composition, epoxy resin cured product and epoxy resin modifier.SOLUTION: An epoxy resin composition contains epoxy resin and lactide.SELECTED DRAWING: None

Description

The present invention relates to epoxy resin compositions, epoxy resin cured products and epoxy resin modifiers.

Epoxy resins are used in various industrial fields as resin materials having excellent heat resistance and mechanical strength. Various means for improving the characteristics of the epoxy resin have been studied depending on the use of the epoxy resin. For example, Patent Document 1 describes an epoxy resin composition containing N-phenylmaleimide as an epoxy resin composition in which the viscosity before curing is reduced without impairing the heat resistance of the cured product.

Japanese Unexamined Patent Publication No. 1-188518

Finding a number of means to improve the properties of epoxy resins is beneficial in view of the diversification of epoxy resin applications.
In view of the above circumstances, it is an object of the present invention to provide a novel epoxy resin composition, an epoxy resin cured product, and an epoxy resin modifier.

Specific means for solving the above problems include the following aspects.
<1> An epoxy resin composition containing an epoxy resin and lactide.
<2> The epoxy resin composition according to <1>, which further contains a curing accelerator.
<3> An epoxy resin cured product, which is a cured product of the epoxy resin composition according to <1> or <2>.
<4> An epoxy resin modifier containing lactide.

According to the present disclosure, novel epoxy resin compositions, epoxy resin cured products, and epoxy resin modifiers are provided.

It is the IR measurement result of the product, GPE and lactide obtained by the model reaction test. It is ¹ H-NMR measurement result of the product obtained by the model reaction test. It is a ¹ H-NMR measurement result of GPE obtained by a model reaction test. It is a ¹ H-NMR measurement result of lactide obtained by a model reaction test. It is the SEC measurement result of the product obtained by the model reaction test.

In the present disclosure, the term "process" includes not only a process independent of other processes but also the process if the purpose of the process is achieved even if the process cannot be clearly distinguished from the other process. ..
The numerical range indicated by using "~" in the present disclosure includes the numerical values before and after "~" as the minimum value and the maximum value, respectively.
In the numerical range described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described stepwise. .. Further, in the numerical range described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.
In the present disclosure, each component may contain a plurality of applicable substances. When a plurality of substances corresponding to each component are present in the composition, the content or content of each component is the total content or content of the plurality of substances present in the composition unless otherwise specified. Means quantity.
In the present disclosure, a plurality of types of particles corresponding to each component may be contained. When a plurality of particles corresponding to each component are present in the composition, the particle size of each component means a value for a mixture of the plurality of particles present in the composition unless otherwise specified.

<Epoxy resin composition>
The epoxy resin composition of the present disclosure contains an epoxy resin and lactide.
The epoxy resin composition having the above structure forms a structure obtained by reacting the epoxy resin and lactide in the cured product obtained by curing the epoxy resin composition. Such an epoxy resin composition is a novel one that has not been reported so far.

According to the epoxy resin composition of the present disclosure, it is possible to impart properties not found in the cured product obtained by curing the epoxy resin alone to the cured product. For example, the cured product obtained by curing the epoxy resin composition of the present disclosure has a smaller mass loss at high temperatures (that is, improved heat resistance) than the cured product obtained by curing only the epoxy resin. ) May. The reason is not always clear, but it is considered that the structure obtained by reacting the epoxy resin formed in the cured product with lactide has some action.

The epoxy resin composition of the present disclosure may contain a structure obtained by reacting lactide with each other in the cured product, in addition to a structure obtained by reacting the epoxy resin and lactide. Lactide is known to form polylactic acid by ring-opening reaction. By introducing a polylactic acid structure into the cured product of the epoxy resin composition by the reaction between lactides, improvement in impact resistance, flexibility, etc. can be expected.

Lactide contained in the epoxy resin composition is a cyclic dimer of lactic acid and is a compound having the following structure. Lactide may be L-form, D-form, or a combination of L-form and D-form.

In the present disclosure, an example of the process of forming the "structure obtained by reacting the epoxy resin and lactide" is shown in the following model reaction. However, the present disclosure is not limited to the following reactions.

As shown in the model reaction, it is considered that the epoxy resin (glycidyl phenyl ether, GPE in the above reaction) reacts with the ring-opened lactide to form a linear or cyclic copolymer. The molecular weight of the copolymer is not particularly limited and can be set according to desired cured product properties and the like.

The conditions for reacting the epoxy resin with lactide are not particularly limited. As a result of the studies by the present inventors, the reaction between the epoxy resin and lactide is carried out under the condition of a relatively high temperature (for example, 180 ° C. or higher) in the presence of a base (diazabicycloundecene, DBU in the above reaction). It was found that it tends to be promoted more.

The amount of lactide contained in the epoxy resin composition is not particularly limited and can be selected according to the desired cured product properties and the like.
For example, the amount of lactide per mol of epoxy resin may be 0.01 mol to 1 mol, 0.05 mol to 0.5 mol, 0.1 mol to 0.2 mol. You may.

(Epoxy resin)
The type of epoxy resin contained in the epoxy resin composition is not particularly limited.
Specifically, the epoxy resin is at least one selected from the group consisting of phenol compounds such as phenol, cresol, xylenol, resorcin, catechol, bisphenol A, and bisphenol F, and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene. A novolak type epoxy resin (phenol novolak type) which is an epoxy obtained by condensing or cocondensing a kind of phenolic compound and an aliphatic aldehyde compound such as formaldehyde, acetaldehyde, propionaldehyde, etc. under an acidic catalyst. Epoxy resin, orthocresol novolac type epoxy resin, etc.); A triphenylmethane type phenol resin obtained by condensing or cocondensing the above phenolic compound with an aromatic aldehyde compound such as benzaldehyde or salicylaldehyde under an acidic catalyst. Triphenylmethane type epoxy resin; a copolymerized epoxy resin obtained by co-condensing the above phenol compound and naphthol compound with an aldehyde compound under an acidic catalyst; Diphenylmethane type epoxy resin which is a diglycidyl ether such as A and bisphenol F; biphenyl type epoxy resin which is an alkyl-substituted or unsubstituted biphenol diglycidyl ether; stillben-type epoxy resin which is a diglycidyl ether of a stillben-based phenol compound; bisphenol Sulfur atom-containing epoxy resin such as diglycidyl ether such as S; epoxy resin which is glycidyl ether of alcohols such as butanediol, polyethylene glycol and polypropylene glycol; polyvalent carboxylic acid compound such as phthalic acid, isophthalic acid and tetrahydrophthalic acid Glysidyl ester type epoxy resin, which is a glycidyl ester of glycidyl ester; glycidylamine type epoxy resin in which active hydrogen bonded to a nitrogen atom such as aniline, aminophenol, diaminodiphenylmethane, isocyanuric acid is replaced with a glycidyl group; dicyclopentadiene and phenol Dicyclopentadiene type epoxy resin which is an epoxy of a cocondensation resin of a compound; vinylcyclohexene diepoxide which is an epoxy of an olefin bond in a molecule, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane Carboxylate, 2- (3,4-epoxy) An alicyclic epoxy resin such as clohexyl-5,5-spiro (3,4-epoxy) cyclohexane-m-dioxane; a paraxylylene-modified epoxy resin which is a glycidyl ether of a paraxylylene-modified phenol resin; a glycidyl ether of a metaxylylene-modified phenol resin. Metaxylylene-modified epoxy resin; Terpen-modified epoxy resin, which is a glycidyl ether of terpen-modified phenol resin; Dicyclopentadiene-modified epoxy resin, which is a glycidyl ether of dicyclopentadiene-modified phenol resin; Epoxy resin; Polycyclic aromatic ring-modified epoxy resin which is a glycidyl ether of a polycyclic aromatic ring-modified phenol resin; Naphthalene type epoxy resin which is a glycidyl ether of a naphthalene ring-containing phenol resin; Halogenated phenol novolac type epoxy resin; Hydroquinone type epoxy resin Trimethylol propane type epoxy resin; Linear aliphatic epoxy resin obtained by oxidizing an olefin bond with a peracid such as peracetic acid; Epoxy aralkyl type phenol resin such as phenol aralkyl resin and naphthol aralkyl resin. Aralkill type epoxy resin; etc. Further, an epoxy resin such as an acrylic resin is also mentioned as an epoxy resin. These epoxy resins may be used individually by 1 type or in combination of 2 or more type.

The epoxy equivalent (molecular weight / number of epoxy groups) of the epoxy resin is not particularly limited. From the viewpoint of the balance of various characteristics such as moldability, reflow resistance and electrical reliability, it is preferably 60 g / eq to 1000 g / eq, and more preferably 80 g / eq to 500 g / eq.

The epoxy equivalent of the epoxy resin shall be a value measured by a method according to JIS K 7236: 2009.

When the epoxy resin is a solid, its softening point or melting point is not particularly limited. From the viewpoint of moldability and reflow resistance, the temperature is preferably 40 ° C. to 180 ° C., and from the viewpoint of handleability when preparing the epoxy resin composition, the temperature is more preferably 50 ° C. to 130 ° C.

The melting point or softening point of the epoxy resin shall be a value measured by differential scanning calorimetry (DSC) or a method according to JIS K 7234: 1986 (ring ball method).

The content of the epoxy resin in the epoxy resin composition is preferably 0.5% by mass to 50% by mass, preferably 2% by mass to 30% by mass, from the viewpoint of strength, fluidity, heat resistance, moldability, and the like. More preferably.

(Hardener)
The epoxy resin composition may contain a curing agent if necessary.
The type of the curing agent is not particularly limited and can be selected according to the desired properties of the cured product and the like. Examples of the curing agent used in combination with the epoxy resin include a phenol curing agent, an amine curing agent, an acid anhydride curing agent, a polymercaptan curing agent, a polyaminoamide curing agent, an isocyanate curing agent, and a blocked isocyanate curing agent. From the viewpoint of heat resistance, a phenol curing agent is preferable, and from the viewpoint of adhesion to an adherend, an amine curing agent is preferable.

Specifically, the phenolic curing agent is a polyhydric phenol compound such as resorcin, catechol, bisphenol A, bisphenol F, substituted or unsubstituted biphenol; phenol, cresol, xylenol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol. , Aminophenol and other phenolic compounds and at least one phenolic compound selected from the group consisting of α-naphthol, β-naphthol, dihydroxynaphthalene and other naphthol compounds, and aldehyde compounds such as formaldehyde, acetaldehyde and propionaldehyde as acidic catalysts. Novolac-type phenolic resin obtained by condensing or co-condensing underneath; phenol-aralkyl resin synthesized from the above-mentioned phenolic compound and dimethoxyparaxylene, bis (methoxymethyl) biphenyl, etc., aralkyl-type phenolic resin such as naphthol-aralkyl resin. Paraxylylene-modified phenolic resin, metaxylylene-modified phenolic resin; melamine-modified phenolic resin; terpen-modified phenolic resin; dicyclopentadiene-type phenolic resin and dicyclopentadiene-type naphthol synthesized by copolymerization of the above phenolic compound and dicyclopentadiene. Resin; Cyclopentadiene-modified phenolic resin; Polycyclic aromatic ring-modified phenolic resin; Biphenyl-type phenolic resin; Obtained by condensing or co-condensing the above phenolic compound with an aromatic aldehyde compound such as benzaldehyde or salicylaldehyde under an acidic catalyst. Triphenylmethane-type phenolic resin to be used; phenolic resin obtained by copolymerizing two or more of these types can be mentioned. These phenol hardeners may be used alone or in combination of two or more.

Specific examples of the amine curing agent include aliphatic amine compounds such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, 4,4'-diamino-dicyclohexylmethane, and diethyltoluene. Aromatic amine compounds such as diamine, 3,3'-diethyl-4,4'-diaminodiphenylmethane, dimethylthiotoluenediamine, 2-methylaniline, imidazole, 2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, etc. Examples of the imidazole compound, imidazoline, 2-methylimidazoline, 2-ethylimidazolin and other imidazoline compounds. Among these, aromatic amine compounds are preferable, and diethyltoluenediamine, 3,3'-diethyl-4,4'-diaminodiphenylmethane and dimethylthiotoluenediamine are more preferable from the viewpoint of storage stability.

The functional group equivalents of other curing agents (hydroxyl equivalents in the case of phenol curing agents, active hydrogen equivalents in the case of amine curing agents) are not particularly limited. From the viewpoint of balance of various characteristics such as moldability, reflow resistance, and electrical reliability, it is preferably 10 g / eq to 1000 g / eq, and more preferably 30 g / eq to 500 g / eq.

The functional group equivalents of other curing agents (hydroxyl equivalents in the case of phenol curing agents, active hydrogen equivalents in the case of amine curing agents) shall be values measured by a method according to JIS K 0070: 1992.

When the curing agent is a solid, its softening point or melting point is not particularly limited. From the viewpoint of moldability and reflow resistance, the temperature is preferably 40 ° C. to 180 ° C., and from the viewpoint of handleability during production of the epoxy resin composition, the temperature is more preferably 50 ° C. to 130 ° C.

The melting point or softening point of the curing agent shall be a value measured in the same manner as the melting point or softening point of the epoxy resin.

When a curing agent is used, the equivalent ratio of the epoxy resin to the curing agent, that is, the ratio of the number of functional groups in the curing agent to the number of functional groups in the epoxy resin (the number of functional groups in the curing agent / the number of functional groups in the epoxy resin) is There are no particular restrictions. From the viewpoint of suppressing each unreacted component to a small extent, it is preferably set in the range of 0.5 to 2.0, and more preferably set in the range of 0.6 to 1.3. From the viewpoint of moldability and reflow resistance, it is more preferable to set the range from 0.8 to 1.2.

(Curing accelerator)
The epoxy resin composition may contain a curing accelerator. The type of the curing accelerator is not particularly limited, and can be selected according to the type of the epoxy resin or the curing agent, the desired properties of the epoxy resin composition, and the like.

Examples of the curing accelerator include diazabicycloalkenes such as 1,5-diazabicyclo [4.3.0] nonen-5 (DBN) and 1,8-diazabicyclo [5.4.0] undecene-7 (DBU). Cyclic amidin compounds such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole; derivatives of the cyclic amidin compound; phenol novolac salts of the cyclic amidin compound or derivatives thereof; Maleic anhydride, 1,4-benzoquinone, 2,5-turquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1 , 4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone and other quinone compounds, and diazophenylmethane and other quinone compounds with π-bonded compounds added to it. Compounds; Cyclic amidinium compounds such as DBU tetraphenylborate salt, DBN tetraphenylborate salt, 2-ethyl-4-methylimidazole tetraphenylborate salt, N-methylmorpholin tetraphenylborate salt; pyridine, triethylamine, tri Tertiary amine compounds such as ethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol; derivatives of the tertiary amine compound; tetra-n-butylammonium acetate, tetra-n-phosphate Ammonium salt compounds such as butylammonium, tetraethylammonium acetate, tetra-n-hexylammonium benzoate, tetrapropylammonium hydroxide; triphenylphosphine, diphenyl (p-tolyl) phosphine, tris (alkylphenyl) phosphine, tris (alkoxyphenyl) ) Hosphin, Tris (alkyl / alkoxyphenyl) phosphin, Tris (dialkylphenyl) phosphin, Tris (trialkylphenyl) phosphin, Tris (tetraalkylphenyl) phosphin, Tris (dialkoxyphenyl) phosphin, Tris (trialkoxyphenyl) phosphine , Tris (tetraalkoxyphenyl) phosphine, trialkylphosphine, dialkylarylphosphine, alkyldiarylphosphine and other tertiary phosphines; compounds of the tertiary phosphine with organic borons and the like. Phosphine compound; said tertiary phosphine or said phosphine compound and maleic anhydride, 1,4-benzoquinone, 2,5-torquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2, Quinone compounds such as 3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, phenyl-1,4-benzoquinone, and compounds having a π bond such as diazophenylmethane. Compounds with additional intramolecular polarization; the tertiary phosphine or the phosphine compound and 4-bromophenol, 3-bromophenol, 2-bromophenol, 4-chlorophenol, 3-chlorophenol, 2-chlorophenol, 4-Ioated phenol, 3-iodinated phenol, 2-iodinated phenol, 4-bromo-2-methylphenol, 4-bromo-3-methylphenol, 4-bromo-2,6-dimethylphenol, 4-bromo -3,5-dimethylphenol, 4-bromo-2,6-di-tert-butylphenol, 4-chloro-1-naphthol, 1-bromo-2-naphthol, 6-bromo-2-naphthol, 4-bromo- A compound having intramolecular polarization obtained by reacting a halogenated phenol compound such as 4'-hydroxybiphenyl and then undergoing a step of dehalogenating; a tetra-substituted phosphonium such as tetraphenylphosphonium, tetra-p-tolylbolate. Tetra-substituted phosphonium and tetra-substituted borate without a phenyl group bonded to a boron atom, such as salts of tetraphenylphosphonium and phenol compounds, salts of tetraalkylphosphonium and partial hydrolyzates of aromatic carboxylic acid anhydrides, etc. Be done.

When the epoxy resin composition contains a curing accelerator, the amount thereof is 0.1 part by mass to 30 parts by mass with respect to 100 parts by mass of the resin component (total amount of epoxy resin, lactide and, if necessary, a curing agent). The amount is preferably 1 part to 15 parts by mass, more preferably 1 part by mass. When the amount of the curing accelerator is 0.1 part by mass or more with respect to 100 parts by mass of the resin component, it tends to cure well in a short time. When the amount of the curing accelerator is 30 parts by mass or less with respect to 100 parts by mass of the resin component, the curing rate is not too fast and a good molded product tends to be obtained.

(Inorganic filler)
The epoxy resin composition of the present disclosure may contain an inorganic filler. The type of inorganic filler is not particularly limited. Specific examples thereof include inorganic materials such as fused silica, crystalline silica, glass, alumina, talc, clay, mica, boron nitride, and aluminum nitride. An inorganic filler having a flame-retardant effect may be used. Examples of the inorganic filler having a flame-retardant effect include aluminum hydroxide, magnesium hydroxide, magnesium oxide, composite metal hydroxide such as a composite hydroxide of magnesium and zinc, zinc borate and the like.

Among the inorganic fillers, silica such as fused silica is preferable from the viewpoint of reducing the coefficient of linear expansion, and alumina is preferable from the viewpoint of high thermal conductivity. As the inorganic filler, one type may be used alone or two or more types may be used in combination. Examples of the form of the inorganic filler include unpowdered beads, spherical beads of powder, and fibers.

When the inorganic filler is in the form of particles, its average particle size is not particularly limited. For example, the average particle size is preferably 0.1 μm to 100 μm, and more preferably 0.3 μm to 50 μm. When the average particle size is 0.1 μm or more, the increase in viscosity of the epoxy resin composition tends to be further suppressed. When the average particle size is 100 μm or less, the filling property tends to be further improved. The average particle size of the inorganic filler is determined as the volume average particle size (D50) by a laser scattering diffraction method particle size distribution measuring device.

The content of the inorganic filler contained in the epoxy resin composition is not particularly limited. From the viewpoint of fluidity and strength, it is preferably 30% by volume to 90% by volume, more preferably 35% by volume to 80% by volume, and 40% to 70% by volume of the entire epoxy resin composition. It is more preferable to have. When the content of the inorganic filler is 30% by volume or more of the entire epoxy resin composition, the properties such as the coefficient of thermal expansion, the thermal conductivity, and the elastic modulus of the cured product tend to be further improved. When the content of the inorganic filler is 90% by volume or less of the entire epoxy resin composition, an increase in the viscosity of the epoxy resin composition is suppressed, the fluidity is further improved, and the moldability tends to be better. ..

[Various additives]
In addition to the above-mentioned components, the epoxy resin composition may contain various additives such as a coupling agent, an ion exchanger, a mold release agent, a flame retardant, and a colorant exemplified below. The epoxy resin composition may contain various additives well known in the art, if necessary, in addition to the additives exemplified below.

(Coupling agent)
The epoxy resin composition may contain a coupling agent. From the viewpoint of enhancing the adhesiveness between the resin component and the inorganic filler, the epoxy resin composition preferably contains a coupling agent. Examples of the coupling agent include known coupling agents such as silane compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane and vinylsilane, titanium compounds, aluminum chelate compounds and aluminum / zirconium compounds. ..

When the epoxy resin composition contains a coupling agent, the amount of the coupling agent is preferably 0.05 parts by mass to 10 parts by mass, and 0.1 parts by mass to 5 parts by mass with respect to 100 parts by mass of the inorganic filler. It is more preferably parts by mass. When the amount of the coupling agent is 0.05 parts by mass or more with respect to 100 parts by mass of the inorganic filler, the adhesiveness with the frame tends to be further improved. When the amount of the coupling agent is 10 parts by mass or less with respect to 100 parts by mass of the inorganic filler, the moldability of the package tends to be further improved.

(Ion exchanger)
The epoxy resin composition may contain an ion exchanger. The epoxy resin composition preferably contains an ion exchanger from the viewpoint of improving the moisture resistance and high temperature standing characteristics of the electronic component device including the element to be sealed. The ion exchanger is not particularly limited, and conventionally known ones can be used. Specific examples thereof include hydrotalcite compounds and hydroxides containing at least one element selected from the group consisting of magnesium, aluminum, titanium, zirconium and bismuth. As the ion exchanger, one type may be used alone or two or more types may be used in combination. Of these, hydrotalcite represented by the following general formula (A) is preferable.

Mg _(1-X) Al _X (OH) ₂ (CO ₃ ) _{X / 2}・ mH ₂ O …… (A)
(0 <X ≤ 0.5, m is a positive number)

When the epoxy resin composition contains an ion exchanger, the content thereof is not particularly limited as long as it is an amount sufficient to capture ions such as halogen ions. For example, it is preferably 0.1 part by mass to 30 parts by mass with respect to 100 parts by mass of the resin component (total amount of epoxy resin, lactide and, if necessary, a curing agent), and 1 part by mass to 10 parts by mass. Is more preferable.

(Release agent)
The epoxy resin composition may contain a mold release agent from the viewpoint of obtaining good mold releasability from the mold at the time of molding. The release agent is not particularly limited, and conventionally known release agents can be used. Specific examples thereof include higher fatty acids such as carnauba wax, montanic acid and stearic acid, ester waxes such as higher fatty acid metal salts and montanic acid esters, and polyolefin waxes such as polyethylene oxide and non-oxidized polyethylene. As the release agent, one type may be used alone or two or more types may be used in combination.

When the epoxy resin composition contains a mold release agent, the amount thereof is 0.01 part by mass to 10 parts by mass with respect to 100 parts by mass of the resin component (total amount of epoxy resin, lactide and, if necessary, a curing agent). Is preferable, and 0.1 parts by mass to 5 parts by mass is more preferable. When the amount of the mold release agent is 0.01 part by mass or more with respect to 100 parts by mass of the resin component, the mold release property tends to be sufficiently obtained. When it is 10 parts by mass or less, better adhesiveness tends to be obtained.

(Flame retardants)
The epoxy resin composition may contain a flame retardant. The flame retardant is not particularly limited, and conventionally known flame retardants can be used. Specific examples thereof include organic or inorganic compounds containing halogen atoms, antimony atoms, nitrogen atoms or phosphorus atoms, metal hydroxides and the like. The flame retardant may be used alone or in combination of two or more.

When the epoxy resin composition contains a flame retardant, the amount thereof is not particularly limited as long as it is sufficient to obtain the desired flame retardant effect. For example, it is preferably 1 part by mass to 30 parts by mass, and 2 parts by mass to 20 parts by mass with respect to 100 parts by mass of the resin component (total amount of epoxy resin, lactide and, if necessary, a curing agent). Is more preferable.

(Colorant)
The epoxy resin composition may contain a colorant. Examples of the colorant include known colorants such as carbon black, organic dyes, organic pigments, titanium oxide, lead tan, and red iron oxide. The content of the colorant can be appropriately selected depending on the purpose and the like. As the colorant, one type may be used alone or two or more types may be used in combination.

The epoxy resin composition may be a solid or a liquid under normal temperature and pressure (for example, 25 ° C. and atmospheric pressure). When the epoxy resin composition is a solid, the shape is not particularly limited, and examples thereof include powder, granules, and tablets. When the epoxy resin composition is in the form of a tablet, it is preferable that the dimensions and mass match the molding conditions of the package from the viewpoint of handleability.

The method for preparing the epoxy resin composition is not particularly limited. When the raw material of the epoxy resin composition is a solid under normal temperature and pressure, a method of sufficiently mixing the components in a predetermined blending amount with a mixer or the like, then melt-kneading with a mixing roll, an extruder or the like, cooling and pulverizing the epoxy resin composition. Can be mentioned. When the raw material of the epoxy resin composition is a liquid under normal temperature and pressure, a method of mixing and kneading using a mixer such as a grinder, a mixing roll, and a planetary mixer, and defoaming as necessary can be mentioned.

The use of the epoxy resin composition is not particularly limited. For example, it may be used as a sealing material (solid sealing material and underfill material) for electronic component devices, fiber reinforced plastic (FRP), insulating material and the like.

<Epoxy resin cured product>
The epoxy resin cured product of the present disclosure is a cured product of an epoxy resin composition containing an epoxy resin and lactide.
The epoxy resin cured product having the above structure contains a structure obtained by reacting the epoxy resin with lactide. Such an epoxy resin cured product is a novel product that has not been reported so far.

The cured epoxy resin of the present disclosure can have properties (excellent heat resistance, etc.) that are not found in the cured product obtained by curing only the epoxy resin.

The cured epoxy resin product of the present disclosure may contain a structure (polylactic acid structure) obtained by reacting lactide with each other, in addition to a structure obtained by reacting the epoxy resin and lactide. This can be expected to improve impact resistance, flexibility, and the like.

The epoxy resin composition used for forming the cured epoxy resin of the present disclosure is not particularly limited as long as it contains an epoxy resin and lactide. For example, the epoxy resin composition described above may be used.

<Epoxy resin modifier>
The epoxy resin modifiers of the present disclosure include lactide.
The epoxy resin modifier of the present disclosure is mixed with an epoxy resin and used in the state of an epoxy resin composition. The epoxy resin modifier can impart characteristics (excellent heat resistance, etc.) not found in the cured product obtained by curing the epoxy resin alone to the cured product.

The epoxy resin modifier may consist of lactide alone or may consist of lactide and components other than lactide. The lactide contained in the epoxy resin modifier may be L-form, D-form, or a combination of L-form and D-form.

The amount of the epoxy resin modifier contained in the epoxy resin composition is not particularly limited and can be selected according to the desired cured product properties. For example, the amount of the epoxy resin modifier (converted to lactide) per 1 mol of the epoxy resin may be 0.01 mol to 1 mol, 0.05 mol to 0.5 mol, or 0.1. It may be mol to 0.2 mol.

The details of the epoxy resin used in combination with the epoxy resin modifier and the components contained in the epoxy resin composition as required are the same as the details of the epoxy resin described above and the components contained in the epoxy resin composition as needed. is there.

Hereinafter, the above-described embodiment will be specifically described with reference to Examples, but the scope of the above-mentioned Embodiment is not limited to these Examples.

<Model reaction test of epoxy resin and lactide>
Glysidylphenyl ether (GPE) and lactide (a mixture of D-form and L-form) were added to the test tube (molar ratio 1: 1), and the mixture was heated under nitrogen substitution until it was uniformly dissolved. Then, 0.2 mL of diazabicycloundecene (DBU) was added, and the reaction was carried out at 200 ° C. for 12 hours. After completion of the reaction, the product was dissolved in chloroform, the solution was transferred to a separatory funnel, a 1N (mol / L) aqueous hydrochloric acid solution was added thereto, and the reaction solution was neutralized by shaking well. Next, water was added and shaken well to wash. Then, anhydrous magnesium sulfate was added, dehydration filtration was performed, and chloroform was completely removed by an evaporator to concentrate. Then, it was added dropwise to diethyl ether to obtain a black viscous substance. This viscous material was placed in a desiccator and dried under reduced pressure.

When the obtained product was subjected to IR measurement, from the results shown in FIG. 1, disappeared absorption due to an epoxy backbone (900 cm around ^-1), absorption confirmed due to the OH group (3300 cm around ^-1) It was found that the reaction proceeded. Further, when ^{1 1} H-NMR measurement was performed, from the results shown in FIGS. 2 to 4, the peak of GPE having an epoxy group (around 3.00 ppm) disappeared as compared with the product after the reaction, which was caused by the OH group. It was found that the reaction proceeded because the peak was confirmed. Furthermore, when size exclusion chromatography (SEC) measurement was performed, it was found from the results shown in FIG. 5 that the polymerization proceeded because a peak was confirmed on the polymer side.

<Synthesis example 1>
Bisphenol A type epoxy resin (structure below) and lactide (mixture of D-form and L-form) were added to the test tube at a molar ratio of 1: 1 and heated under nitrogen substitution until they were uniformly dissolved. Then, 0.2 mL of DBU was added, and the reaction was carried out at 200 ° C. for 24 hours to obtain a cured product. Similarly, a cured product was obtained even when the amount of lactide per 1 mol of the bisphenol A type epoxy resin was changed to 0.2 mol or 0.1 mol.

<Synthesis example 2>
Triphenylmethane type epoxy resin (structure below) and lactide (mixture of D-form and L-form) were added to a test tube at a molar ratio of 1: 1 and heated under nitrogen substitution until they were uniformly dissolved. Then, 0.2 mL of DBU was added, and the reaction was carried out at 200 ° C. for 24 hours to obtain a cured product. Similarly, a cured product was obtained even when the amount of lactide per 1 mol of the triphenylmethane type epoxy resin was changed to 0.2 mol.

<Synthesis example 3>
A glycidylamine type epoxy resin (structure below) and lactide (a mixture of D-form and L-form) were added to a test tube at a molar ratio of 1: 1 and heated under nitrogen substitution until they were uniformly dissolved. Then, 0.2 mL of DBU was added, and the reaction was carried out at 200 ° C. for 24 hours to obtain a cured product. Similarly, a cured product was obtained even when the amount of lactide per 1 mol of the glycidylamine type epoxy resin was changed to 0.2 mol or 0.1 mol.

<Synthesis example 4>
Bisphenol F type epoxy resin (structure below) and lactide (mixture of D-form and L-form) were added to a test tube at a molar ratio of 1: 1 and heated under nitrogen substitution until they were uniformly dissolved. Then, 0.2 mL of DBU was added, and the reaction was carried out at 200 ° C. for 24 hours to obtain a cured product. Similarly, a cured product was obtained even when the amount of lactide per 1 mol of the bisphenol F type epoxy resin was changed to 0.2 mol or 0.1 mol.

<Synthesis example 5>
Biphenyl type epoxy resin (structure below) and lactide (mixture of D-form and L-form) were added to a test tube at a molar ratio of 1: 1 and heated under nitrogen substitution until they were uniformly dissolved. Then, 0.2 mL of DBU was added, and the reaction was carried out at 200 ° C. for 24 hours to obtain a cured product. Similarly, a cured product was obtained even when the amount of lactide per 1 mol of the biphenyl type epoxy resin was changed to 0.2 mol or 0.1 mol.

<Synthesis example 6>
Biphenyl type epoxy resin (structure below) and lactide (mixture of D-form and L-form) were added to a test tube at a molar ratio of 1: 1 and heated under nitrogen substitution until they were uniformly dissolved. Then, 0.2 mL of DBU was added, and the reaction was carried out at 200 ° C. for 24 hours to obtain a cured product. Similarly, a cured product was obtained even when the amount of lactide per 1 mol of the biphenyl type epoxy resin was changed to 0.2 mol or 0.1 mol.

<Evaluation of heat resistance>
The cured products obtained in Synthesis Examples 1, 2 and 3 were subjected to thermogravimetric analysis (TGA) as an index of heat resistance. The measurement was carried out by heating to 450 ° C. at a heating rate of 10 ° C./min in a nitrogen atmosphere. As a reference, the cured product obtained (0 mol) without adding lactide to the epoxy resin used in each synthetic example was also measured. The results are shown in Table 1.

In Table 1, "T1" is the temperature at the start of mass reduction, "T2" is the temperature when the mass reduction rate reaches 5%, and "T3" is the temperature at which the mass reduction rate reaches 10%. The temperature of the time.

As shown in Table 1, the cured product of the epoxy resin composition containing lactide tended to suppress the mass loss due to heating as compared with the cured product of the epoxy resin composition containing no lactide.

Claims (4)

An epoxy resin composition containing an epoxy resin and lactide. The epoxy resin composition according to claim 1, further containing a curing accelerator. An epoxy resin cured product, which is a cured product of the epoxy resin composition according to claim 1 or 2. Epoxy resin modifier containing lactide.