JP2010083836A - Method for producing epoxy compound, and catalyst - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suitable oxidation catalyst which is easily removable and also suitable for the oxidation reaction in a method for producing an epoxy compound by the oxidation of a carbon-carbon double bond. <P>SOLUTION: This method for producing the epoxy compound is characterized by oxidizing the compound having the carbon-carbon double bond by using tungstic acid, a quaternary ammonium salt, buffer solution and hydrogen peroxide, then precipitating the catalyst containing the tungstic acids and quaternary ammonium salt, and separating it from reaction liquid. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing an epoxy compound by oxidation of a carbon-carbon double bond, and an oxidation catalyst suitable for the oxidation reaction.

Epoxy resins are generally cured with various curing agents, resulting in cured products with excellent mechanical properties, water resistance, chemical resistance, heat resistance, electrical properties, etc., adhesives, paints, laminates, moldings It is used in a wide range of fields such as materials, casting materials and resists. In recent years, especially in the field of semiconductor-related materials, electronic devices such as mobile phones with cameras, ultra-thin liquid crystals, plasma TVs, and light-weight notebook computers have become key to light, thin, short, and small. Very high characteristics have been demanded for packaging materials represented by resins. In particular, the structure of the tip package is complicated, and there are an increasing number of things that are difficult to seal without liquid sealing. For example, a cavity down type structure such as Enhanced BGA needs to be partially sealed and cannot be handled by transfer molding. For these reasons, the development of highly functional liquid epoxy resins has been demanded.
In recent years, RTM has been used as a composite material, a car body or a ship structural material because of its simplicity of manufacturing method. In such a composition, a low-viscosity epoxy resin is desired because it is easily impregnated into carbon fiber or the like.

  In addition, in the field of optoelectronics, especially in recent years, advanced information technology, in order to smoothly transmit and process a huge amount of information, technology that utilizes optical signals will be developed instead of conventional signal transmission using electrical wiring. In particular, in the field of optical components such as optical waveguides, blue LEDs, and optical semiconductors, development of resins having excellent transparency is desired. In response to these requirements, alicyclic epoxy resins have attracted attention. Specifically, it is an epoxy resin group having an epoxycyclohexane skeleton.

Conventionally, such alicyclic epoxy resins have been produced by an oxidation reaction of a compound having a cyclohexene structure with a peracid (such as peracetic acid). However, peracid is difficult to handle due to its poor stability, and a production method that can be used more safely has been demanded.
From such a background, in recent years, epoxidation using hydrogen peroxide as a safer oxidizing agent has been studied. In general, it is known to use tungstic acids, molybdic acids and quaternary ammonium salts as catalysts. However, the problem of this reaction is that the quaternary ammonium salt used has a strong fat solubility, and it is difficult to remove the quaternary ammonium salt from the organic solvent, and it remains in the product. In order to solve such a problem, a technique of insolubilizing the catalyst such as loading the catalyst on silica gel or the like is used. However, such a catalyst requires a large amount of catalyst because of its low activity.
JP 2002-69079 A Japanese Patent Laid-Open No. 2001-17863 JP 2005-169363 A JP 2004-115455 A JP-A-5-213919

  An object of the present invention is to provide an oxidation catalyst that is easy to remove a catalyst and suitable for the oxidation reaction in a method for producing an epoxy compound by oxidation of a carbon-carbon double bond.

  As a result of intensive studies in view of the actual situation as described above, the present inventors have completed the present invention.

That is, the present invention provides (1)
A compound having a carbon-carbon double bond is oxidized with tungstic acid, quaternary ammonium salt, buffer solution and hydrogen peroxide, and then a catalyst containing tungstic acid and quaternary ammonium salt is precipitated and separated from the reaction solution. A method for producing an epoxy compound (2)
The above (the method for producing an epoxy compound according to 1 (3), wherein the quaternary ammonium salt has 30 or more carbon atoms
A method for producing an epoxy compound (4), wherein the deposited catalyst according to (1) is used again.
A carbon-carbon double bond, which is a peroxometalate composed of a quaternary ammonium salt having a total carbon number of 30 or more and tungstic acid, and contains a phosphorus element and an alkali metal (or alkaline earth metal) element The present invention relates to an oxidation catalyst for a compound having

  According to the present invention, not only can the epoxidation reaction by oxidation proceed efficiently, but also the catalyst can be recycled. Epoxy compounds produced by this production method are easily purified and have little residual catalyst, such as electrical / electronic materials, molding materials, casting materials, laminate materials, paints, adhesives, resists, optical materials, etc. It is useful for a wide range of.

In the production method of the present invention, a compound having a carbon-carbon double bond is oxidized using a tungstic acid, a quaternary ammonium salt, a buffer, hydrogen peroxide, and then a catalyst containing the tungstic acid and the quaternary ammonium salt is obtained. An epoxy compound is obtained by precipitating, separating from the reaction solution, purifying the resulting solution, and distilling off the solvent. Further, the deposited catalyst can be reused, and the oxidation reaction can proceed similarly.

The compound having a carbon-carbon double bond to be used as a raw material in the present invention is not particularly limited as long as it is a compound having a carbon-carbon double bond in the molecule. It is preferably in the ring, and particularly those having a cyclohexene structure and further a cyclohexene carboxyester structure in the molecule are preferred. Specific compounds include esterification reaction of cyclohexene carboxylic acid and alcohol or esterification reaction of cyclohexene methanol and carboxylic acid (Tetrahedron vol.36 p.2409 (1980), Tetrahedron Letter p.4475 (1980)), Alternatively, it can also be produced by Tyschenko reaction of cyclohexene aldehyde (Japanese Patent Laid-Open Nos. 2003-170059 and 2004-262871), and also transesterification of cyclohexene carboxylic acid ester (Japanese Patent Laid-Open No. 2006-052187).
The alcohol is not particularly limited as long as it is a compound having an alcoholic hydroxyl group, but ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,5-pentane. Diols, diols such as 1,6-hexanediol and cyclohexanedimethanol, triols such as glycerin, trimethylolethane, trimethylolpropane, trimethylolbutane, 2-hydroxymethyl-1,4-butanediol, pentaerythritol, etc. And tetraols. Examples of carboxylic acids include oxalic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, adipic acid, and cyclohexanedicarboxylic acid.

Examples of the tungstic acid include tungstic acid; phosphotungstic acid such as 12-tungstophosphoric acid, 12-tungstoboric acid or 18-tungstophosphoric acid; silicotungstic acid such as 12-tungstosilicic acid and salts thereof.
Examples of the counter cation of these salts include quaternary ammonium ions, alkaline earth metal ions, and alkali metal ions.
Specifically, tetramethylammonium ion, benzyltriethylammonium ion, tridecanylmethylammonium ion, dilauryldimethylammonium ion, trioctylmethylammonium ion, trialkylmethyl (mixed type of octyl group and decanyl group) ammonium ion, Quaternary ammonium ions such as hexadecylmethylammonium ion, trimethylstearylammonium ion, tetrapentylammonium ion, cetyltrimethylammonium ion, benzyltributylammonium ion, tricaprylmethylammonium ion, dicetyldimethylammonium ion, calcium ion magnesium ion, etc. Alkaline earth metal ions, sodium, potassium, cesium and other alkalis Although such genera ions include, but are not limited to.
The amount used is 1.0 to 20 mmol in terms of metal element (tungstenic acid is tungsten atom, molybdic acid is molybdenum atom) to 1 mol of double bond of the compound having carbon-carbon double bond, preferably Is 2.0 to 20 mmol, more preferably 2.5 to 10 mmol.

As the quaternary ammonium salt, a quaternary ammonium salt having a total carbon number of 30 or more can be used. In particular, the alkyl chain is preferably an all aliphatic chain, particularly a dialkyldimethylammonium salt (alkyl is the same or different and has at least 2 carbon atoms) or a trialkylmethylammonium salt (the definition of alkyl is the same as above). .
Specifically, dicetyldimethylammonium salt, tricetylmethylammonium salt, dipentadecyldimethylammonium salt, tripentadecylmethylammonium salt, dioctadecyldimethylammonium salt, trioctadecylmethylammonium salt, ditetradecyldimethylammonium salt, Examples include, but are not limited to, tetradecylmethylammonium salt and di-cured tallow alkyldimethylammonium salt.
These anionic species are not particularly limited, and specific examples include halide ions, nitrate ions, sulfate ions, hydrogen sulfate ions, acetate ions, carbonate ions, and the like, but are not limited thereto.
Of these ammonium salts, tricetylmethylammonium chloride, di-tallow alkyl dimethyl ammonium chloride, di-tallow alkyl dimethyl ammonium acetate and the like are preferable in view of market availability.
The amount of tungstic acid and quaternary ammonium carboxylate used is preferably 1.1 to 10 times the valence of the tungstic acid used. More preferably, it is 1.2-6.0 times equivalent, More preferably, it is 1.3-4.5 times equivalent.
For example, since tungstic acid is divalent with H ₂ WO ₄ , the quaternary ammonium carboxylate is preferably in the range of 2.2 to 20 mol with respect to 1 mol of tungstic acid. Moreover, since it is trivalent in the case of tungstophosphoric acid, it is similarly 3.3 to 20 mol, and in the case of silicotungstic acid, it is tetravalent, so 4.4 to 40 mol is preferable.
When the amount of the quaternary ammonium carboxylate is lower than 1.1 times equivalent of the valence of tungstic acids, the epoxidation reaction is difficult to proceed (in some cases, the reaction proceeds faster), and a by-product is produced. The problem is that things are easy to make. When the amount is more than 10 times equivalent, it is not preferable because the treatment of the excess quaternary ammonium carboxylate is not only difficult but also has a function of suppressing the reaction.

In the present invention, a buffer solution is used. Any buffer can be used, but it is preferable to use an aqueous phosphate solution in this reaction. In some cases, the above tungstic acids may be combined to form a buffer solution. The pH is preferably adjusted between pH 2 and 6, more preferably pH 3 to 5. When the pH is 2 or less, the hydrolysis reaction and polymerization reaction of the epoxy group easily proceed. On the other hand, when the pH is 6 or more, there is a problem that the reaction becomes extremely slow and the reaction time is too long.
For example, in the case of a phosphoric acid-phosphate aqueous solution which is a preferable buffer, 0.1 to 10 molar equivalents of phosphoric acid (or a phosphate such as sodium dihydrogen phosphate) is used with respect to hydrogen peroxide. And a method of adjusting pH with a basic compound (for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, etc.). Here, it is preferable that the pH is added so that the above-mentioned pH is obtained when hydrogen peroxide is added. It is also possible to adjust using sodium dihydrogen phosphate, disodium hydrogen phosphate, or the like. The preferred phosphate concentration is 0.1 to 60% by weight, preferably 5 to 45% by weight.

This reaction is epoxidized using hydrogen peroxide. As the hydrogen peroxide used in this reaction, an aqueous solution having a hydrogen peroxide concentration of 10 to 40% by weight is preferable because of easy handling. When this concentration exceeds 40% by weight, it is not preferable because handling becomes difficult and the decomposition reaction of the produced epoxy compound also easily proceeds.
The amount of tungstic acid used in the oxidation reaction is usually 0.1 to 2.0 mol%, preferably 0.1 to 1.5 mol% of tungsten atoms relative to 1 mol of the compound having a carbon-carbon double bond. More preferably, it is 0.1-1.0 mol%.
The amount of the buffer used is usually 0.5 to 150 parts by weight, preferably 0.5 to 100 parts by weight, based on 100 parts by weight of the starting compound having a carbon-carbon double bond. The reaction does not change significantly depending on the amount used.

  This reaction uses an organic solvent. The amount of the organic solvent to be used is 0.3 to 10 by weight, preferably 0.3 to 5, and more preferably 0.8 to the compound 1 having a carbon-carbon double bond as a reaction substrate. 5 to 2.5. When the weight ratio exceeds 10, the progress of the reaction is extremely slow, which is not preferable. Specific examples of usable organic solvents include alkanes such as hexane, cyclohexane and heptane, aromatic hydrocarbon compounds such as toluene and xylene, and alcohols such as methanol, ethanol, isopropanol, butanol, hexanol and cyclohexanol. it can. In some cases, ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and anone; ethers such as diethyl ether, tetrahydrofuran and dioxane; ester compounds such as ethyl acetate, butyl acetate and methyl formate; A tolyl compound can also be used.

The production method of the present invention is specifically described below.
As a specific reaction operation method, a compound having a carbon-carbon double bond, hydrogen peroxide, tungstic acid, a buffer solution, a quaternary ammonium salt and an organic solvent are added and stirred in two layers. There is no specific designation for the stirring speed. Since heat is often generated when hydrogen peroxide is added, a method of gradually adding hydrogen peroxide after adding each component may be used.

  Although reaction temperature is not specifically limited, 30-90 degreeC is preferable, More preferably, it is 35-75 degreeC, Especially 35 degreeC-60 degreeC is preferable. When the reaction temperature is too high, the hydrolysis reaction tends to proceed, and when the reaction temperature is low, the reaction rate becomes extremely slow. Depending on the concentration of the reaction, the catalyst may precipitate and the reaction may not proceed easily.

  Although the reaction time depends on the reaction temperature, the amount of catalyst, etc., from the viewpoint of industrial production, a long-time reaction is not preferable because it consumes a large amount of energy. A preferable range is 1 to 48 hours, preferably 3 to 36 hours, and more preferably 4 to 24 hours.

  After completion of the reaction, the water layer is discarded or the catalyst is deposited without discarding. Examples of the method for depositing the catalyst include, but are not limited to, cooling, adding a poor solvent for the catalyst, or a combination thereof. In the case of cooling, it is preferably 30 ° C. or lower, preferably 25 ° C. or lower, and even if a small amount of water remains in the system, precipitation of crystals is promoted. Since the poor solvent varies depending on the catalyst, it cannot be generally stated. However, alcohols and ketones having a high polarity, such as methanol and acetone, which have a relatively good affinity for water are preferable.

  The deposited catalyst takes the form of crystals or oil. By removing the deposited catalyst by filtration or liquid separation, a roughly purified epoxy compound solution can be obtained. The removed catalyst can be reused, details of which will be described later.

After completion of the reaction or after catalyst deposition, quenching of excess hydrogen peroxide is performed. The quenching treatment is preferably performed using a basic compound. By performing quenching with a basic compound, the remaining amount of the catalyst can be further reduced. It is also preferable to use a reducing agent and a basic compound in combination.
As a preferred treatment method, after adjusting the pH to 6 to 8 with a basic compound, the remaining hydrogen peroxide is quenched using a reducing agent. When the pH is 6 or less, there is a large exotherm when reducing excess hydrogen peroxide, and the produced epoxy compound may be partially hydrolyzed. Further, when the pH is 8 or more, hydrolysis of the epoxy compound and further hydrolysis of the ester bond may be caused.

  Examples of the reducing agent include sodium sulfite, sodium thiosulfate, hydrazine, and oxalic acid. As the amount of the reducing agent used, excess hydrogen peroxide is usually 0.01 to 20 times mol, more preferably 0.05 to 10 times mol, still more preferably 0.05 to 3 times mol, based on the number of moles. is there.

Basic compounds include metal hydroxides such as sodium hydroxide, potassium hydroxide, magnesium hydroxide and calcium hydroxide, metal carbonates such as sodium carbonate and potassium carbonate, phosphorus such as sodium phosphate and sodium hydrogen phosphate. Examples thereof include basic solids such as acid salts, ion exchange resins, and alumina.
The amount used is water or organic solvents (for example, aromatic hydrocarbons such as toluene and xylene, ketones such as methyl isobutyl ketone and methyl ethyl ketone, hydrocarbons such as cyclohexane, heptane and octane, methanol, ethanol, isopropyl alcohol, etc. And other alcohols such as alcohols) is usually 0.01 to 20 times mol, more preferably 0.05 to 10 times mol, and still more preferably, relative to the number of moles of excess hydrogen peroxide. Is 0.05 to 3 moles. These may be added as water or a solution of the above-mentioned organic solvent, or may be added alone.
When a solid base that does not dissolve in water or an organic solvent is used, it is preferable to use an amount of 1 to 1000 times by weight with respect to the amount of hydrogen peroxide remaining in the system. More preferably, it is 10-500 times, More preferably, it is 10-300 times. In the case of using a solid base that does not dissolve in water or an organic solvent, the treatment may be carried out after separation of an aqueous layer and an organic layer described later.

After the hydrogen peroxide quench (or after catalyst deposition and removal), the organic and aqueous layers are separated. At this time, when the organic layer and the aqueous layer are not separated, or when no organic solvent is used, the above-mentioned organic solvent is added for operation, and the reaction product is extracted from the aqueous layer. The organic solvent used in this case is 0.5 to 10 times, preferably 0.5 to 5 times in weight ratio with respect to the compound having a carbon-carbon double bond as a raw material to be obtained. This operation is repeated several times as necessary, and the separated organic layer is purified by washing with water as necessary.
The obtained organic layer is removed by ion exchange resin, metal oxide, activated carbon, composite metal salt, clay mineral, etc., if necessary, further washed with water, filtered, etc., then the solvent is distilled off, The target epoxy compound is obtained.

  The obtained epoxy compound can be used as various resin raw materials such as epoxy acrylate and derivatives thereof, oxazolidone compounds, and cyclic carbonate compounds.

Hereinafter, the catalyst of the present invention will be described. The catalyst of the present invention can be obtained in the step of oxidizing the compound having a carbon-carbon double bond as described above.
After completion of the oxidation reaction, the resulting catalyst does not have a regular crystal structure, but partially has a peroxometalate structure (detectable by mass spectrum). They also exist in the form of salt bonds with quaternary ammonium ions. Furthermore, when analyzed by elemental analysis or the like, the alkali metal ions (or alkaline earth metal ions) used in the used buffer solution are also introduced. The constituent elements of the catalyst of the present invention are tungsten element, phosphorus element, alkali metal element (or alkaline earth metal element), nitrogen, oxygen and carbon.

The catalyst of the present invention can be used as an oxidation (epoxidation) catalyst for a compound having a carbon-carbon double bond.
Specifically, using a compound having a carbon-carbon double bond, the catalyst of the present invention, a buffer solution, an organic solvent, hydrogen peroxide, and, if necessary, tungstic acids and a quaternary ammonium salt in the same manner as described above. react. The amount of each component used may be as described above.
For example, after adding the catalyst of the present invention to a sodium phosphate buffer and a two-layer solution of toluene, a compound having a carbon-carbon double bond is further added and stirred. Hydrogen peroxide solution is gradually dropped here to carry out the reaction. After completion of the reaction, hydrogen peroxide is quenched with a basic substance and a reducing agent, the catalyst is removed with an adsorbent and the like, washed with water, and the solvent is recovered to obtain the desired epoxy compound.

Hereinafter, the curable resin composition (referred to as the curable resin composition of the present invention) containing the epoxy compound (referred to as the epoxy compound of the present invention) obtained as described above will be described.
The curable resin composition of the present invention contains the epoxy compound of the present invention. In the curable resin composition of the present invention, two methods of heat curing with a curing agent (curable resin composition A) and cationic curing with an acid as a curing catalyst (curable resin composition B) can be applied.

  In the curable resin composition A and the curable resin composition B, the epoxy compound of the present invention can be used alone or in combination with other epoxy resins. When used in combination, the proportion of the epoxy compound of the present invention in all epoxy resins (the epoxy compound of the present invention and other epoxy resins; the same shall apply hereinafter) is preferably 30% by weight or more, particularly preferably 40% by weight or more. However, when using the epoxy compound of this invention as a modifier of curable resin composition, it adds in the ratio of 1 to 30 weight%.

  Examples of other epoxy resins that can be used in combination with the epoxy compound of the present invention include novolac type epoxy resins, bisphenol A type epoxy resins, biphenyl type epoxy resins, triphenylmethane type epoxy resins, phenol aralkyl type epoxy resins, and the like. Specifically, bisphenol A, bisphenol S, thiodiphenol, fluorene bisphenol, terpene diphenol, 4,4′-biphenol, 2,2′-biphenol, 3,3 ′, 5,5′-tetramethyl- [ 1,1′-biphenyl] -4,4′-diol, hydroquinone, resorcin, naphthalenediol, tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol (Phenol, alkyl-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, dihydroxynaphthalene, etc.) and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, o-hydroxybenzaldehyde, p-hydroxyacetophenone, -Hydroxyacetophenone, dicyclopentadiene, furfural, 4,4'-bis (chloromethyl) -1,1'-biphenyl, 4,4'-bis (methoxymethyl) -1,1'-biphenyl, 1,4-bis Glycidyl ethers derived from polycondensates with (chloromethyl) benzene, 1,4-bis (methoxymethyl) benzene, etc., and modified products thereof, halogenated bisphenols such as tetrabromobisphenol A or alcohols Examples thereof include, but are not limited to, solid or liquid epoxy resins such as alicyclic epoxy resins, glycidyl amine epoxy resins, and glycidyl ester epoxy resins. These may be used alone or in combination of two or more.

Hereinafter, each curable resin composition will be described.
Thermal curing with a curing agent (curable resin composition A)
Examples of the curing agent contained in the curable resin composition A of the present invention include amine compounds, acid anhydride compounds, amide compounds, phenol compounds, and carboxylic acid compounds. Specific examples of the curing agent that can be used include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide, polyamide resin synthesized from linolenic acid and ethylenediamine, phthalic anhydride, trimellitic anhydride Acid, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, phenol resin, bisphenol A, bisphenol F, bisphenol S Fluorene bisphenol, terpene diphenol, 4,4'-biphenol, 2,2'-biphenol, 3,3 ', 5,5'-tetramethyl- [1,1'-biphenyl] -4 4′-diol, hydroquinone, resorcin, naphthalenediol, tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenols (phenol, alkyl-substituted phenol, naphthol, Alkyl-substituted naphthol, dihydroxybenzene, dihydroxynaphthalene, etc.) and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, o-hydroxybenzaldehyde, p-hydroxyacetophenone, o-hydroxyacetophenone, dicyclopentadiene, furfural, 4,4'-bis (Chloromethyl) -1,1′-biphenyl, 4,4′-bis (methoxymethyl) -1,1′-biphenyl, 1,4′-bis (chloromethyl) benzene, 1,4 ′ Polycondensates with bis (methoxymethyl) benzene and the like, modified products thereof, halogenated bisphenols such as tetrabromobisphenol A, imidazole, trifluoroborane-amine complexes, guanidine derivatives, condensates of terpenes and phenols, etc. Although it is mentioned, it is not limited to these. These may be used alone or in combination of two or more.

  In the curable resin composition A of the present invention, the amount of the curing agent used is preferably 0.7 to 1.2 equivalents relative to 1 equivalent of the epoxy groups of all epoxy resins. When less than 0.7 equivalent or more than 1.2 equivalent with respect to 1 equivalent of epoxy group, curing may be incomplete and good cured properties may not be obtained.

  In the curable resin composition A of the present invention, a curing accelerator may be used in combination with the curing agent. Specific examples of curing accelerators that can be used include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2- (dimethylaminomethyl) phenol, 1,8-diaza- And tertiary amines such as bicyclo (5,4,0) undecene-7, phosphines such as triphenylphosphine, and metal compounds such as tin octylate. When using a hardening accelerator, 0.1-5.0 weight part is used as needed with respect to 100 weight part of epoxy resins.

  The curable resin composition A of the present invention may contain a phosphorus-containing compound as a flame retardant imparting component. The phosphorus-containing compound may be a reactive type or an additive type. Specific examples of phosphorus-containing compounds include trimethyl phosphate, triethyl phosphate, tricresyl phosphate, trixylylenyl phosphate, cresyl diphenyl phosphate, cresyl-2,6-dixylylenyl phosphate, 1,3-phenylenebis ( Phosphoric acid esters such as dixylylenyl phosphate), 1,4-phenylenebis (dixylylenyl phosphate), 4,4′-biphenyl (dixylylenyl phosphate); 9,10-dihydro-9-oxa Phosphanes such as -10-phosphaphenanthrene-10-oxide, 10 (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide; epoxy resin and active hydrogen of the phosphanes A phosphorus-containing product obtained by reacting with Poxy compounds, red phosphorus and the like can be mentioned, and phosphoric esters, phosphanes or phosphorus-containing epoxy compounds are preferable, and 1,3-phenylenebis (dixylylenyl phosphate), 1,4-phenylenebis (dixylylene). Nyl phosphate), 4,4′-biphenyl (dixylylenyl phosphate) or phosphorus-containing epoxy compounds are particularly preferred. The phosphorus-containing compound content is preferably phosphorus-containing compound / total epoxy resin = 0.1 to 0.6 (weight ratio). If it is 0.1 or less, the flame retardancy is insufficient, and if it is 0.6 or more, there is a concern that it may adversely affect the hygroscopicity and dielectric properties of the cured product.

  Furthermore, binder resin can also be mix | blended with the curable resin composition A of this invention as needed. Examples of the binder resin include butyral resins, acetal resins, acrylic resins, epoxy-nylon resins, NBR-phenol resins, epoxy-NBR resins, polyamide resins, polyimide resins, and silicone resins. However, it is not limited to these. The blending amount of the binder resin is preferably in a range that does not impair the flame retardancy and heat resistance of the cured product, and is usually 0.05 to 50 parts by weight, preferably 0.05 to 20 parts per 100 parts by weight of the resin component. Part by weight is used as needed.

  An inorganic filler can be added to the curable resin composition A of the present invention as necessary. Examples of inorganic fillers include crystalline silica, fused silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, spinel, titania, talc, and the like. However, the present invention is not limited to these. These may be used alone or in combination of two or more. The content of these inorganic fillers is 0 to 95% by weight in the curable resin composition A of the present invention. Furthermore, a silane coupling agent, a release agent such as stearic acid, palmitic acid, zinc stearate, and calcium stearate, various compounding agents such as pigments, and various thermosetting resins are added to the curable resin composition of the present invention. can do.

  The curable resin composition A of the present invention is obtained by uniformly mixing each component. The curable resin composition A of the present invention can be easily made into a cured product by a method similar to a conventionally known method. For example, the epoxy compound of the present invention, a curing agent and, if necessary, a curing accelerator, a phosphorus-containing compound, a binder resin, an inorganic filler, and a compounding agent are sufficient until uniform using an extruder, kneader, roll, etc. as necessary. To obtain a curable resin composition, and the curable resin composition is melted and then molded using a casting or transfer molding machine, and further heated at 80 to 200 ° C. for 2 to 10 hours. Can be obtained.

  Further, the curable resin composition A of the present invention is dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone to obtain a curable resin composition varnish, and glass fiber. The curable resin composition A of the present invention is cured by hot press-molding a prepreg obtained by impregnating a base material such as carbon fiber, polyester fiber, polyamide fiber, alumina fiber, or paper and drying by heating. It can be a thing. The solvent used in this case is usually 10 to 70% by weight, preferably 15 to 70% by weight in the mixture of the curable resin composition A of the present invention and the solvent. Moreover, the epoxy resin hardened | cured material which contains a carbon fiber by a RTM system with a liquid composition can also be obtained.

  Moreover, the curable resin composition A of this invention can be used also as a modifier of a film type composition. Specifically, it can be used to improve the flexibility of the B-stage. When obtaining such a film-type resin composition, such a film-type resin composition is applied onto the release film using the curable resin composition A of the present invention as the curable resin composition varnish, After removing the solvent under heating, it is obtained as a sheet-like adhesive by performing B-stage. This sheet-like adhesive can be used as an interlayer insulating layer in a multilayer substrate or the like.

  Furthermore, the curable resin composition A of the present invention can be used in general applications in which a thermosetting resin such as an epoxy resin is used. For example, adhesives, paints, coating agents, molding materials (sheets, films) , FRP, etc.), insulating materials (including printed circuit boards, wire coatings, etc.), sealing materials, sealing materials, cyanate resin compositions for substrates, and acrylic ester resins as resist curing agents, etc. And additives to other resins.

  Examples of the adhesive include civil engineering, architectural, automotive, general office, and medical adhesives, and electronic material adhesives. Among these, adhesives for electronic materials include interlayer adhesives for multilayer substrates such as build-up substrates, die bonding agents, semiconductor adhesives such as underfills, BGA reinforcing underfills, anisotropic conductive films ( ACF) and an adhesive for mounting such as anisotropic conductive paste (ACP).

  As sealing agents, potting, dipping, transfer mold sealing for capacitors, transistors, diodes, light-emitting diodes, ICs, LSIs, potting sealings for ICs, LSIs such as COB, COF, TAB, flip chip For example, underfill for QFP, BGA, CSP, etc., and sealing (including reinforcing underfill) can be used.

Cationic curing with an acidic curing catalyst (curable resin composition B)
When the curable resin composition of the present invention is cured with an acidic curing catalyst, the curable resin composition of the present invention contains a photopolymerization initiator or a thermal polymerization initiator. Furthermore, the curable resin composition B may be prepared by using a diluent, a polymerizable monomer, a polymerizable oligomer, a polymerization initiation auxiliary agent, a photosensitizer, an inorganic filler, a pigment, an ultraviolet absorber, an antioxidant, if necessary. Various known compounds and materials such as stabilizers, silane coupling materials, release agents, and various thermosetting resins may be contained.

Furthermore, specific examples of the inorganic filler and the release agent that the curable resin composition B of the present invention contains as necessary include those similar to the curable resin composition A.
In the curable resin composition B, cationic polymerization is preferable, and photocationic polymerization is particularly preferable. Cationic catalysts (hereinafter simply referred to as “photocation polymerization initiators”) include onium salts such as iodonium salts, sulfonium salts, and diazonium salts, and these can be used alone or in combination of two or more. The amount of the cationic photopolymerization initiator used is preferably 0.01 to 50 parts by weight, more preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the total epoxy resin.

  Furthermore, it is possible to simultaneously use one or two or more of these photocationic polymerization initiators, known polymerization initiation assistants and photosensitizers. Examples of polymerization initiators include, for example, benzoin, benzyl, benzoin methyl ether, benzoin isopropyl ether, acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4-methylthiophenyl) -2-morpholinolpropan-1-one, N, N-dimethylaminoacetophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1- Chloroanthraquinone, 2-amylanthraquinone, 2-isopropylthioxatone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, acetophenone di Chiruketaru, benzophenone, 4-methylbenzophenone, 4,4'-dichlorobenzophenone, 4,4'-bis-diethylamino benzophenone, and a photo-radical polymerization initiator such as Michler's ketone. The usage-amount of polymerization initiation adjuvants, such as photoradical polymerization initiator, is 0.01-30 weight part with respect to 100 weight part of components which can carry out photoradical, Preferably it is 0.1-10 weight part.

  Specific examples of the photosensitizer include anthracene, 2-isopropylthioxatone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, acridine orange, acridine yellow, phosphine R, benzo Examples include flavin, cetoflavin T, perylene, N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, triethanolamine, triethylamine and the like. The usage-amount of a photosensitizer is 0.01-30 weight part with respect to 100 weight part of all the epoxy resin components, Preferably it is 0.1-10 weight part.

  The curable resin composition B of the present invention can be obtained by uniformly mixing each component. It is also possible to dissolve in an organic solvent such as polyethylene glycol monoethyl ether, cyclohexanone, or γ-butyrolactone and make it uniform, and then use it after removing the solvent by drying. The solvent used here is usually 10 to 70% by weight, preferably 15 to 70% by weight in the mixture of the curable resin composition B of the present invention and the solvent. The curable resin composition B of the present invention can be cured by irradiating with ultraviolet rays, but the amount of ultraviolet irradiation varies depending on the curable resin composition, and therefore is determined by the respective curing conditions. What is necessary is just the irradiation amount which a photocurable curable resin composition hardens | cures, and should just satisfy | fill the curing conditions with favorable adhesive strength of hardened | cured material. Since it is necessary for light to be transmitted through the details during the curing, the epoxy compound of the present invention and the curable resin composition B are desired to be highly transparent. Moreover, it is difficult to cure completely by light irradiation alone in these epoxy resin-based photocuring, and in applications where heat resistance is required, it is necessary to complete the curing by heating after light irradiation.

  The heating after the light irradiation may be performed in the normal curing temperature range of the curable resin composition B. For example, the range of 30 minutes to 7 days at room temperature to 150 ° C. is suitable. Although it changes depending on the composition of the curable resin composition B, the higher the temperature range, the more effective the curing is after light irradiation, and the short heat treatment is effective. By performing such heat after-curing, an effect of aging treatment is obtained.

  Moreover, since the shape of the hardened | cured material obtained by making these curable resin composition B harden | cure can take various according to a use, it is not specifically limited, For example, it can also be set as shapes, such as a film form, a sheet form, and a bulk form. The molding method varies depending on the applicable part and member. For example, a casting method, a casting method, a screen printing method, a spin coating method, a spray method, a transfer method, a dispenser method, or the like can be applied. Although it is mentioned, it is not limited to these. As the mold, polishing glass, hard stainless steel polishing plate, polycarbonate plate, polyethylene terephthalate plate, polymethyl methacrylate plate, or the like can be applied. In addition, a polyethylene terephthalate film, a polycarbonate film, a polyvinyl chloride film, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a polyimide film, or the like can be applied in order to improve releasability from the mold.

  For example, when used for a cation curable resist, first, a photo cation curable resin composition B dissolved in an organic solvent such as polyethylene glycol monoethyl ether, cyclohexanone, or γ-butyrolactone is used as a copper-clad laminate, ceramic On the substrate such as a substrate or a glass substrate, the composition of the present invention is applied with a film thickness of 5 to 160 μm by a method such as screen printing or spin coating to form a coating film. The coating film is preliminarily dried at 60 to 110 ° C., and then irradiated with ultraviolet rays (for example, a low pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp, a laser beam, etc.) through a negative film having a desired pattern. Then, post-exposure baking is performed at 70 to 120 ° C. Thereafter, the unexposed portion is dissolved and removed (developed) with a solvent such as polyethylene glycol monoethyl ether, and if necessary, sufficient by irradiation with ultraviolet rays and / or heating (eg, at 100 to 200 ° C. for 0.5 to 3 hours). Curing is performed to obtain a cured product. In this way, it is also possible to obtain a printed wiring board.

  The cured product obtained by curing the curable resin composition A and the curable resin composition B of the present invention can be used for various applications including optical component materials. The optical material refers to general materials used for applications that allow light such as visible light, infrared light, ultraviolet light, X-rays, and lasers to pass through the material. More specifically, in addition to LED sealing materials such as lamp type and SMD type, the following may be mentioned. It is a peripheral material for liquid crystal display devices such as a substrate material, a light guide plate, a prism sheet, a polarizing plate, a retardation plate, a viewing angle correction film, an adhesive, and a film for a liquid crystal such as a polarizer protective film in the liquid crystal display field. In addition, color PDP (plasma display) sealing materials, antireflection films, optical correction films, housing materials, front glass protective films, front glass replacement materials, adhesives, and LED displays that are expected as next-generation flat panel displays LED molding materials, LED sealing materials, front glass protective films, front glass substitute materials, adhesives, and substrate materials for plasma addressed liquid crystal (PALC) displays, light guide plates, prism sheets, deflection plates , Phase difference plate, viewing angle correction film, adhesive, polarizer protective film, front glass protective film in organic EL (electroluminescence) display, front glass substitute material, adhesive, and various in field emission display (FED) Film substrate Front glass protective films, front glass substitute material, an adhesive. In the optical recording field, VD (video disc), CD / CD-ROM, CD-R / RW, DVD-R / DVD-RAM, MO / MD, PD (phase change disc), disc substrate material for optical cards, Pickup lenses, protective films, sealing materials, adhesives and the like.

  In the field of optical equipment, they are still camera lens materials, finder prisms, target prisms, finder covers, and light receiving sensor parts. It is also a photographic lens and viewfinder for video cameras. Projection lenses for projection televisions, protective films, sealing materials, adhesives, and the like. These include lens materials, sealing materials, adhesives, and films for optical sensing devices. In the field of optical components, they are fiber materials, lenses, waveguides, element sealing materials, adhesives and the like around optical switches in optical communication systems. Optical fiber materials, ferrules, sealing materials, adhesives, etc. around the optical connector. For optical passive components and optical circuit components, there are lenses, waveguides, LED sealing materials, CCD sealing materials, adhesives, and the like. These are substrate materials, fiber materials, device sealing materials, adhesives, etc. around an optoelectronic integrated circuit (OEIC). In the field of optical fiber, it is an optical fiber for lighting, light guides for decorative displays, sensors for industrial use, displays / signs, etc., and for communication infrastructure and home digital equipment connection. As the semiconductor integrated circuit peripheral material, it is a resist material for microlithography for LSI and VLSI material. In the field of automobiles and transport equipment, automotive lamp reflectors, bearing retainers, gear parts, anti-corrosion coatings, switch parts, headlamps, engine internal parts, electrical parts, various interior and exterior parts, drive engines, brake oil tanks, and automotive defenses Rusted steel plates, interior panels, interior materials, protective / bundling wireness, fuel hoses, automobile lamps, glass replacements. In addition, it is a multilayer glass for railway vehicles. In addition, they are toughness imparting agents for aircraft structural materials, engine peripheral members, protective / bundling wireness, and corrosion-resistant coatings. In the construction field, it is interior / processing materials, electrical covers, sheets, glass interlayers, glass substitutes, and solar cell peripheral materials. For agriculture, it is a house covering film. Next-generation optical / electronic functional organic materials include organic EL element peripheral materials, organic photorefractive elements, optical amplification elements that are light-to-light conversion devices, optical arithmetic elements, substrate materials around organic solar cells, fiber materials, elements Sealing material, adhesive and the like.

  Other uses of the optical material include general uses in which the curable resin composition A is used. For example, adhesives, paints, coating agents, molding materials (including sheets, films, FRP, etc.), In addition to insulating materials (including printed circuit boards and wire coatings), sealants, additives to other resins and the like can be mentioned.

  Examples of the adhesive include civil engineering, architectural, automotive, general office, and medical adhesives, and electronic material adhesives. Among these, adhesives for electronic materials include interlayer adhesives for multilayer substrates such as build-up substrates, die bonding agents, semiconductor adhesives such as underfills, BGA reinforcing underfills, anisotropic conductive films ( ACF) and an adhesive for mounting such as anisotropic conductive paste (ACP).

  As sealing agents, potting, dipping, transfer mold sealing for capacitors, transistors, diodes, light-emitting diodes, ICs, LSIs, potting sealings for ICs, LSIs such as COB, COF, TAB, flip chip For example, underfill for sealing, and sealing (reinforcing underfill) when mounting IC packages such as BGA and CSP.

  The curable resin composition A and the curable resin composition B of the present invention can also be applied to an optical semiconductor device. Such an optical semiconductor device can be manufactured by sealing an optical semiconductor element (optical semiconductor chip) with the curable resin composition of the present invention. As the sealing method, a method of molding (casting and curing) a sealing resin for sealing the optical semiconductor element by a method such as casting, potting or printing can be employed. The molding conditions can be adopted as they are as the molding conditions in the sealing molding of a semiconductor element with a curable resin composition that has been conventionally performed, and if appropriately set according to the composition of the curable resin composition for optical semiconductor encapsulation, etc. Good.

  EXAMPLES Next, the present invention will be described more specifically with reference to examples. In the following, parts are parts by weight unless otherwise specified. The present invention is not limited to these examples. In the examples, the epoxy equivalent was measured using JIS K-7236, and the viscosity was measured using an E-type viscometer at 25 ° C.

Example 1
A flask equipped with a stirrer, a reflux condenser, and a stirrer was charged with 30 parts of a 10% by weight sodium dihydrogen phosphate aqueous solution and 1.6 parts of 12-tungstophosphoric acid while purging with nitrogen, and 10% by weight disodium hydrogen phosphate. The pH was adjusted to 5.0 with an aqueous solution. Further, 150 parts of toluene was added and 3.0 parts of ditallow alkyldimethylammonium chloride (10% by weight of isopropanol produced by Lion Akzo, total number of carbon atoms 34 to 38: trade name Arcade 2HP flakes) was added while stirring at 15 ° C. Stirring for a minute produced a quaternary ammonium salt of phosphotungstic acid. Here, the formula (1)

After adding 110 parts of the compound represented by formula (1), this solution was heated to 50 ° C., and while stirring, 106 parts of 35 wt% aqueous hydrogen peroxide was gradually added, followed by a further reaction at 50 ° C. for 6 hours. Stir. After completion of the reaction, the reaction solution was cooled to 20 degrees and left as it was for 12 hours.
Subsequently, the precipitated catalyst was separated by filtration. The obtained catalyst was white crystals, dried after filtration, and used in Example 3. Here, the residual tungsten concentration of the organic layer was measured and found to be 600 ppm. Thereafter, the reaction solution was adjusted to pH 7.5 with an aqueous 1% by weight sodium hydroxide solution, and the aqueous layer was discarded. Further, 50 parts of an aqueous 20% by weight sodium thiosulfate solution was added, and the mixture was stirred for 1 hour and allowed to stand. did. Thereafter, the organic layer separated into two layers was taken out.
To the obtained organic layer, 5 parts of bentonite (Hojoen Bengel SH) and 5 parts of activated carbon (CP2 made by Ajinomoto Fine-Techno) were added and stirred at room temperature for 2 hours, followed by nitrogen pressure filtration and further with 100 parts of toluene. The solid was washed and mixed with the previously obtained solution. This solution was washed three times with 100 parts of water, and the organic solvent was distilled off using a rotary evaporator to obtain 112 parts of the target epoxy compound (EP1). The obtained epoxy compound was light yellow and the epoxy equivalent was 131 g / eq. The viscosity was 235 mPa · s. The amount of remaining tungsten was 13 ppm.

Example 2
In Example 1, di-tallow alkyl dimethyl ammonium chloride 3.0 parts (Arcade 2HP flakes), di-tallow alkyl dimethyl ammonium acetate 6.0 parts (made by Lion Akzo, concentration 50% by weight hexane solution, total carbon number 34-38: commodity The reaction was carried out in the same manner except that the name Arcade 2HT acetate was used.
The catalyst deposited after the completion of the reaction was oily (resinous), and the organic layer was removed by decantation and passed through filter paper to remove excess catalyst. The portion where the liquid was mixed was taken out separately, 50 parts of acetone was added to precipitate the catalyst, and only the organic layer was taken out again by decantation. Here, the residual tungsten concentration of the organic layer was measured and found to be 940 ppm.
After processing in the same manner as in Example 1, the obtained epoxy compound (EP2) is a pale yellow liquid and has an epoxy equivalent of 130 g / eq. The viscosity was 224 mPa · s. The amount of remaining tungsten was 11 ppm.

Comparative Example 1
A flask equipped with a stirrer, a reflux condenser, and a stirrer was charged with 30 parts of a 10% aqueous solution of sodium dihydrogen phosphate and 1.6 parts of 12-tungstophosphoric acid while purging with nitrogen. The pH was adjusted to 5.0. Further, 150 parts of toluene was added and 3.0 parts of ditallow alkyldimethylammonium chloride (10% by weight of isopropanol from Lion Akzo, total carbon number of 34 to 38) was added while stirring, and the mixture was stirred at 40 ° C. for 15 minutes. A quaternary ammonium salt of phosphotungstic acid was produced. Here, after adding 110 parts of the compound of the formula (1), this solution was heated to 50 ° C., and while stirring, 106 parts of 35% aqueous hydrogen peroxide was gradually added. The mixture was further stirred for 6 hours. Tungsten in the reaction solution was 6400 ppm. The obtained reaction solution was adjusted to pH 7.5 with an aqueous 1% by weight sodium hydroxide solution, and the aqueous layer was discarded. Further, 50 parts of an aqueous 20% by weight sodium thiosulfate solution was added and stirred for 1 hour. I put it. Thereafter, the organic layer separated into two layers was taken out.
To the obtained organic layer, 5 parts of bentonite (Hojoen Bengel SH) and 5 parts of activated carbon (CP2 made by Ajinomoto Fine-Techno) were added and stirred at room temperature for 2 hours, followed by nitrogen pressure filtration and further with 100 parts of toluene. The solid was washed and mixed with the previously obtained solution. This solution was washed with 100 parts of water three times and a rotary evaporator was used to distill off the organic solvent to obtain 108 parts of a comparative epoxy compound (EP3). The resulting epoxy compound was light yellow and the epoxy equivalent was 132 g / eq. The viscosity was 233 mPa · s. The amount of remaining tungsten was 65 ppm.

Example 3
A flask equipped with a stirrer, a reflux condenser, and a stirrer was purged with nitrogen, and 6 parts of 10 wt% aqueous sodium dihydrogen phosphate solution, 10 wt% aqueous disodium hydrogen phosphate solution, sodium tungstate dihydrate 0.1 The pH was adjusted to 5.0. Further, 30 parts of toluene was added and 0.3 part of the catalyst of the present invention obtained in Example 1 was added while stirring, followed by stirring at 40 ° C. for 15 minutes. After adding 22 parts of the compound of the formula (1) to this, the temperature was raised to 50 ° C., and while stirring, 21.2 parts of 35 wt% hydrogen peroxide water was gradually added. Stir for 6 hours. The obtained reaction solution was adjusted to pH 7.5 with a 1% by weight aqueous sodium hydroxide solution, and the aqueous layer was discarded. Further, 10 parts of a 20% by weight aqueous sodium thiosulfate solution was added and stirred for 1 hour. I put it. Thereafter, the organic layer separated into two layers was taken out.
To the resulting organic layer, 1 part bentonite (Hojoen Bengel SH) and 1 part activated carbon (Ajinomoto Fine-Techno CP2) were added and stirred at room temperature for 2 hours, followed by nitrogen pressure filtration and 30 parts toluene. The solid was washed and mixed with the previously obtained solution. This solution was washed with 30 parts of water three times, and a rotary evaporator was used to distill off the organic solvent to obtain 20 parts of the target epoxy compound (EP4). The resulting epoxy compound was light yellow and the epoxy equivalent was 130 g / eq. The viscosity was 229 mPa · s. The amount of remaining tungsten was 39 ppm.

  According to the present invention, by depositing the catalyst, the catalyst remains in the product even if the same amount of the adsorbent, and the epoxidation reaction is performed again using the deposited catalyst. Can do.

Claims (4)

A compound having a carbon-carbon double bond is oxidized with tungstic acid, quaternary ammonium salt, buffer solution and hydrogen peroxide, and then a catalyst containing tungstic acid and quaternary ammonium salt is precipitated and separated from the reaction solution. A method for producing an epoxy compound, comprising: The method for producing an epoxy compound according to claim 1, wherein the quaternary ammonium salt has a total carbon number of 30 or more.   A method for producing an epoxy compound, wherein the precipitated catalyst according to claim 1 is used again.   A carbon-carbon double bond, which is a peroxometalate composed of a quaternary ammonium salt having a total carbon number of 30 or more and tungstic acid, and contains a phosphorus element and an alkali metal (or alkaline earth metal) element An oxidation catalyst for a compound having