JPH0627177B2 - Polyvalent phenol novolac glycidyl ether, its manufacturing method and use - Google Patents

Description

TECHNICAL FIELD The present invention relates to an epoxy resin, and more particularly to a polyhydric phenol novolac glycidyl ether which exhibits excellent properties as a material for sealing electronic components such as semiconductor elements.

2. Description of the Related Art In recent years, with the increase in density and size of semiconductor devices in electronic components such as large-scale integrated circuits, demand for higher reliability has been increasing. Resin encapsulation is used for the package of this semiconductor device because it is inexpensive and can be mass-produced. The thermosetting resin for sealing is required to have a small amount of hydrolyzable chlorine and a small stress applied to the semiconductor element. To meet the latter requirement, it becomes necessary for the cured product to have a low elastic modulus. In order to obtain a cured product having a low elastic modulus, it is considered to add a flexibility-imparting agent to glycidyl ether of cresol novolak, but this lowers the glass transition temperature of the cured product and lowers the heat resistance. Further, it has been considered to add a butadiene-acrylonitrile copolymer having functional groups at both terminals of the molecule, but there are problems such as deterioration of electrical characteristics and reduction of insulation resistance.

Various glycidyl ethers of polyhydric phenols have been developed as a method for obtaining a cured product having a low elastic modulus, but these also lower the glass transition temperature and the heat resistance of the cured product. Further, no one satisfying the requirement of low content of hydrolyzable chlorine, which is another required characteristic for a sealing material, has not been obtained. For example, Japanese Patent Publication No. 51-41919 has 1,2-
The glycidyl ether of polyhydric phenol obtained by the reaction of polybutadiene and phenol is described as having good flexibility. However, the heat distortion temperature, which is correlated with the glass transition temperature, is about 30 ° C. lower than that of the commercially available solid bisphenol A glycidyl ether-based cured product according to Example 1 of the patent. This solid bisphenol A
The heat distortion temperature of a cured product containing glycidyl ether as the main component is lower than the heat denaturation temperature of a cured product containing glycidyl ether of cresol novolac as a main component, which is generally used for sealing materials, by about 40 ° C.

Problems to be Solved by the Invention Generally, lowering the elastic modulus lowers the glass transition temperature. An object of the present invention is to obtain a glycidyl ether of a polyhydric phenol which is excellent in flexibility and heat resistance and can provide a cured product with a small amount of impurity ions generated.

Means for Solving the Problems As a result of earnest research on a novel polyhydric phenol glycidyl ether satisfying the above-mentioned requirements, the present inventors have found that in the structure of polyhydric phenol, each phenol unit is represented by the formula: It has been found that such a requirement is satisfied by using a glycidyl ether of a polyhydric phenol novolac having a molecular structure that is bonded via a specific group and a methylene group represented by is there.

That is, the present invention has the general formula (In the formula, R _{1 to} R ₆ are the same or different groups selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aromatic group and a halogen atom, and R ₇ is a hydrogen atom, a carbon number of 1 Is a group selected from the group consisting of 4 alkyl groups and aromatic groups, and n is a number of 1.5 or more and 25 or less on average.), Glycidyl ether of polyhydric phenol novolac.

Specific examples of the substituents R _{1 to} R ₆ include hydrogen atom, methyl group, phenyl group, benzyl group, chlorine atom, bromine atom,
It is an iodine atom or the like, preferably a hydrogen atom or a bromine atom.

Specific examples of the substituent R ₇ include a hydrogen atom, a methyl group, an ethyl group and the like, and a hydrogen atom is preferable.

The number average number of repeating units n is 1.5 or more and 25 or less on average, and preferably 2 or more and 15 or less. When n exceeds 25, a large amount of a high molecular weight product is produced, and the glycidyl ether has a high viscosity even under high temperature conditions, which makes handling difficult. When the number of units n is less than 2, the glycidyl ether becomes a semi-solid or viscous liquid at room temperature, making it difficult to handle. The number average molecular weight is about 500 to 10,000.
Is the range. The number average molecular weight is determined by the vapor pressure osmotic pressure method, and the number average repeating unit number is calculated from this.

The polyhydric phenol glycidyl ether of the present invention has the general formula (In the formula, R _{1 to} R ₆ are the same or different groups selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aromatic group and a halogen atom.) Polycondensation with an aldehyde represented by the general formula R CHO (III) (wherein R is a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms and an aromatic group). To give polyhydric phenol, and then polyhydric phenol is glycidyl etherified with epihalohydrin.

Bisphenols of the present invention include, for example, U.S. Pat.
It can be produced by the method described in Japanese Patent No. 746. That is, the general formula (In the formula, R _{8 to} R ₁₀ are the same or different groups selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aromatic group and a halogen atom.) By heating propenylphenols, general formula (In the formula, R _{1 to} R ₆ are the same or different groups selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aromatic group and a halogen atom.) obtain. Further, hydrogenation of this dimer gives the bisphenol represented by the general formula (II).

Specific examples of aldehydes used in the production of the polyhydric phenol novolac of the present invention include formaldehyde, acetaldehyde, benzaldehyde and the like.

In order to polycondensate the bisphenol and aldehydes of the present invention into polyhydric phenol novolac, a commonly used method for producing a novolac type phenol resin can be applied, and even in a batch system, as described in JP-A-51-130498. It may be a continuous method. An example of the manufacturing method is encyclopedia
Inorganic acids such as hydrochloric acid, phosphoric acid and sulfuric acid, or paratoluene sulfonic acid, shu, as described in Phenolic Resins, page 10, page 1, of Polymer Science and Technology (Interscience Publishers). It is produced by condensation polymerization of phenols and aldehydes using an organic acid such as an acid or a metal salt such as zinc acetate as a catalyst. If necessary, an aromatic solvent may be used. The polyphenol obtained in this way has the general formula (In the formula, R _{1 to} R ₆ are the same or different groups selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aromatic group and a halogen atom, and R ₇ is a hydrogen atom and a carbon number. It is a group selected from the group consisting of 1 to 4 alkyl groups, and n is an average number of 1.5 or more and 25 or less.).

The novel polyphenol novolak of the present invention can be generally used as a curing agent when an epoxy resin is the main component.

In order to glycidyl etherify the polyhydric phenol novolac thus obtained, a method usually used for producing the glycidyl ether from monohydric or polyhydric phenol can be applied. For example, polyphenols are dissolved in epihalohydrin, and an aqueous alkali metal hydroxide solution is continuously added to this solution, while water and epihalohydrin are distilled from the reaction mixture, and the distilled liquid is separated to remove the aqueous layer. The production method of returning epihalohydrin to the reaction system can be used. Specific examples of epihalohydrin include epichlorohydrin, epibromhydrin and the like, but epichlorohydrin is preferable from the viewpoint of industrial availability.

The glycidyl ether of polyhydric phenol novolac of the present invention is used in various applications as a composition in which a curing agent, a curing accelerator and an inorganic filler are mixed.

Examples of the curing agent include phenol novolac, diaminodiphenylmethane, diaminodiphenyl sulfone, metaphenylenediamine, phthalic anhydride, tetrahydrophthalic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic acid anhydride. Examples of the inorganic filler include silica, alumina, talc, clay and glass fiber.

As the curing accelerator, imidazoles, tertiary amines,
Examples include phenols. If necessary, an internal release agent such as stearic acid, calcium stearate, carnauba wax or montan wax, and a flame retardant imparting agent such as glycidyl ether of tetrabromobisphenol can be added.

The amount of the curing agent, the filler, the curing accelerator, and the internal release agent varies depending on the type, but as a general rule, the curing agent should be equivalent to the number of moles of epoxy groups in the polyhydric phenol novolac glycidyl ether. The amount of the functional group is the number of moles, the amount of the filler is such that the filler is close to the closest packing to the volume of the total amount of the compound, and the curing accelerator is the amount of the catalyst, the internal amount. The release agent is used in an amount of about 0.2 to 2.0% by weight based on the total amount of the release agent.

The polyhydric phenol novolac glycidyl ether obtained by the method of the present invention is a cured product having a lower elastic modulus than the conventional orthocresol novolac glycidyl ether or phenol novolac glycidyl ether, and lowers the glass transition temperature. It can be prevented, and the content of hydrolyzable chlorine is small.

Therefore, the polyhydric phenol novolac glycidyl ether of the present invention can be suitably used as a sealant for semiconductor integrated circuits by blending the above-mentioned various compounding agents.

Further, the main component of the glycidyl ether of the present invention, and dicyandiamide, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenyl sulfone, hexahydrophthalic anhydride, pyromellitic dianhydride, diethyltriamine, a curing agent such as triethylenetriamine,
The curing accelerator is dissolved in a solvent, glass cloth, glass non-woven cloth, polyester cloth, polyester non-woven cloth, organic such as asbestos paper, and a method of laminating and molding a prepreg that is dried after impregnating an inorganic fiber base material. Different glycidyl ethers can be used as the base compound for laminates.

EXAMPLES The present invention will be described below with reference to examples.

The epoxy equivalent in the present invention is defined as gram equivalent per mol of glycidyl ether group. In addition, hydrolyzable chlorine is quantified by back titration with a silver nitrate solution of chloride ions desorbed when glycidyl ether of a novolac-type substituted phenol resin is dissolved in dioxane and an alcohol solution of potassium hydroxide is added and heated at reflux for 30 minutes. It is defined as the weight percentage of chlorine atoms in the compound. The softening point is measured by JIS-K2531 (petroleum asphalt softening point test method (annular method)). The number average molecular weight was measured by the vapor pressure osmosis method.

Example 1 (1) Synthesis of polyhydric phenol novolac 1 equipped with a thermometer, a cooling pipe, a dropping funnel, and a stirrer 1
A flask was charged with 0.5 mol of 2-methyl-2,4bis (p-hydroxyphenyl) pentane (purity: 95%) and 0.01 mol of paratoluenesulfonic acid as a catalyst, and the amount was about 10
Heated to 0 ° C. Subsequently, a 37% formalin aqueous solution (containing 0.2 mol of formaldehyde) was continuously added from the dropping funnel over 1 hour. After incubating for 5 hours after dropping, NaOH
The catalyst was neutralized with an aqueous solution, and unreacted substances and water were removed by concentration to obtain a solid resin at room temperature. The softening point of this resin was 101 ° C. and the number average molecular weight was 730. This resin was subjected to ¹⁸ C-NMR measurement using deuterium-substituted chloroform as a solvent. The chart is shown in FIG.

Assignment of peaks in the ¹⁸ C-NMR chart in FIG. 1 is as follows.

29.8ppm, 36.7ppm, 53.0ppm 36.0ppm, 25.2ppm, 31.1ppm Aromatic ring carbon: Approx. 112 to 155ppm (2) Synthesis of glycidyl ether of polyhydric phenol novolac Thermometer, separation tube, dropping funnel and stirrer were attached. 1
In a flask, 1.0 mol of the polyhydric phenol obtained in (1) (as a phenolic hydroxyl group) is dissolved in 7.0 mol of epichlorohydrin. While maintaining the temperature at 80 ° C. and the pressure at 250 mmHg, 48% NaOH aqueous solution was continuously added within 6 hours.
During this time, epichlorohydrin and water were azeotropically liquefied to be liquefied and separated into an organic layer and an aqueous layer by a separation tube, the aqueous layer was removed outside the system, and the organic layer was circulated inside the system. After completion of the reaction, the temperature was kept for 1 hour to evaporate and remove unreacted epichlorohydrin, and the reaction product was dissolved in methyl isobutyl ketone. Next, after removing the by-product salt, methyl isobutyl ketone was evaporated and removed to obtain a solid resin at room temperature.

The softening point of this resin was 69 ° C., the number average molecular weight was 1050, the epoxy equivalent was 216, and the hydrolyzable chlorine was 0.06 wt%. Also, by dissolving this resin in deuterium-substituted acetone,
¹³ C-NMR was measured. The chart is shown in FIG.

Assignment of peaks in the ¹³ C-NMR chart in FIG. 2 is as follows.

27.2ppm, 36.7ppm, 51.9ppm 35.7ppm, 24.2ppm, 29.2ppm 42.6ppm, 49.0ppm, 68.3ppm Aromatic ring carbon: Approx. Glycidyl ether of phenol
1.0 mol (specifically, 206 g as an epoxy group)
And phenol novolac 1.0 mol (phenolic hydroxide
As a base) and 0.8 part by weight as a curing accelerator based on the total amount.
TrisPhenol (made by Sumitomo Chemical Co., Ltd., Sumicure
D) was roll-kneaded to obtain a composition. Then add this composition
It was molded into a 1 mm sheet by pressure / heating press. This success
The molded product is cured at 170 ° C for 5 hours to make a cured molded product.
It was The viscoelasticity measurement result of this molded product is shown in FIG. Gala
The transition temperature was 199 ° C.

Comparative Example 1 Commercially available cresol novolac glycidyl ether
Sumiepoxy manufactured by Tomo Chemical Co., Ltd. ESCN-220)
As an agent, a cured molded article having the same formulation as in (3) of Example 1
Had made. The viscoelasticity measurement result of this molded product is shown in FIG.
The glass transition temperature was 200 ° C.

Comparative Example 2 2-Methyl-2,4-bis (p-hydroxyphenyl)
Using pentane (purity 95%) as a raw material, (2) of Example 1
A glycidyl ether of polyhydric phenol was obtained by the method described in 1.
This glycidyl ether of polyhydric phenol is liquid at room temperature, has an epoxy equivalent of 200 and hydrolyzable chlorine of 0.
It was 09 wt%.

A cured molded article was prepared by using the glycidyl ether of polyhydric phenol as a main ingredient and the same formulation as in (3) of Example 1. The viscoelasticity measurement result of this molded product is shown in FIG. The glass transition temperature was 136 ° C.

To explain FIG. 3 in detail, the horizontal axis represents the temperature during viscoelasticity measurement, the left side of the vertical axis represents the dynamic elastic modulus, and the right side of the vertical axis represents tan δ.
Indicates. The solid line is the measurement result for the cured molded article of Example 1, the dotted line is for Comparative Example 1, and the alternate long and short dash line is for the cured molded article of Comparative Example 2. The upper solid line 1, dotted line 2 and dashed-dotted line 3 indicate the dynamic elastic modulus, which is simply expressed as elastic modulus in the text. The lower solid line 1 ', the dotted line 2', and the alternate long and short dash line 3'indicate tan δ.

The peak of tan δ near −70 ° C. is called secondary dispersion and is attributed to the micro Brownian motion of the molecule. The peaks of tan δ around 140 ° C. and around 200 ° C. are called main dispersion and are attributed to the motion of the whole molecule, and the temperature at the peak point of tan δ is taken as the glass transition temperature.

EFFECT OF THE INVENTION At present, glycidyl ether of cresol novolac as shown in Comparative Example 1 is mainly used for semiconductor encapsulation. On the other hand, there is a demand for a glycidyl ether having a lower elastic modulus and a higher glass transition temperature.

The polyhydric phenol novolac glycidyl ether of the present invention has a lower elastic modulus than the conventional cresol novolac glycidyl ether and flexible glycidyl ether, and has the same glass transition temperature and hydrolyzable chlorine content. And, as the main component of the composition for semiconductor encapsulation,
It has excellent characteristics.

[Brief description of drawings]

FIG. 1 is a ¹³ C-NMR chart of the polyhydric phenol novolac obtained in (1) of Example 1. FIG. 2 is a ¹³ C-NMR chart of the glycidyl ether of polyhydric phenol novolac obtained in (2) of Example 1. FIG. 3 is a viscoelasticity measurement result (dynamic elastic modulus or tan δ-temperature relationship diagram) of the cured molded articles of Example 1 and Comparative Examples 1 and 2. In FIG. 3, 1, 2 and 3 show the dynamic elastic modulus-temperature relationship of the cured molded articles of Example 1 and Comparative Examples 1 and 2, respectively. Further, 1 ', 2', and 3'indicate the tan δ-temperature relationship of the cured molded products of Example 1 and Comparative Examples 1 and 2, respectively.

Continuation of front page (56) Reference JP-A-59-133218 (JP, A) JP-A-59-36123 (JP, A) JP-A-59-109514 (JP, A) JP-A-59-147015 (JP , A)

Claims (3)

[Claims] 1. A general formula (In the formula, R _{1 to} R ₆ are groups selected from the group consisting of hydrogen atoms, alkyl groups having 1 to 8 carbon atoms, aromatic groups and halogen atoms, and R ₇ is a hydrogen atom, having 1 to 4 carbon atoms. A polyvalent phenol novolac glycidyl ether represented by the formula: n is a group selected from the group consisting of an alkyl group and an aromatic group, and n is a number of 1.5 or more and 25 or less on average. 2. General formula (In the formula, R _{1 to} R ₆ are groups selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aromatic group and a halogen atom.) The bisphenol represented by the general formula R ₇ CHO (III) (in the formula, R ₇ is a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms and an aromatic group) and polycondensed with an aldehyde. With phenol,
Then, the polyhydric phenol is glycidyl etherified with epihalohydrin, the general formula (In the formula, R _{1 to} R ₆ are groups selected from the group consisting of hydrogen atoms, alkyl groups having 1 to 8 carbon atoms, aromatic groups and halogen atoms, and R ₇ is a hydrogen atom, having 1 to 4 carbon atoms. A group selected from the group consisting of an alkyl group and an aromatic group, and n is a number of 1.5 or more and 25 or less on average.) The method for producing a glycidyl ether of a polyhydric phenol novolac represented by the formula: 3. General formula (In the formula, R _{1 to} R ₆ are groups selected from the group consisting of hydrogen atoms, alkyl groups having 1 to 8 carbon atoms, aromatic groups and halogen atoms, and R ₇ is a hydrogen atom, having 1 to 4 carbon atoms. A group selected from the group consisting of an alkyl group and an aromatic group, and n is a number of 1.5 or more and 25 or less on average.), A semiconductor integrated circuit sealing agent comprising a polyhydric phenol novolac glycidyl ether represented by