JPH09328558A - Method for forming granular epoxy resin product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the productivity and economy by applying an eternal force to a supercooled crystalline epoxy resin while kept at a specified temperature to grow crystal nuclei and then granulating the resin. SOLUTION: An external force is applied to a supercooled crystalline epoxy resin having a mesogen skeleton of the formula [wherein X is -N=N-, -CH=CH-, -C-CO-, -CH=C(CH3 )-, -CH=CH(CN)-, -C≡C-, -CH=CH-CO-, or a single bond; and R7 and R8 are each a 1-6C linear or cyclic alkyl, H or a halogen] while kept in a temperature range from the glass transition temperature to the melting point to grow crystal nuclei, and the resin is then ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a granular product of an electric / electronic material such as an adhesive, a paint, an insulating material and a laminated board, and particularly an epoxy resin useful for sealing an electronic component.

[0002]

2. Description of the Related Art An amorphous epoxy resin which is solid at room temperature is generally taken out in a molten state in a manufacturing method, cooled to room temperature and solidified, and then ground into a product. Further, a crystalline epoxy resin having a melting point of room temperature or higher is taken out, crystallized, and then subjected to a pulverizing step to reach a product. However, a crystalline epoxy resin having a melting point of room temperature or higher and having a supercooling property, which is taken out from the synthesis step, becomes a viscous liquid or a semi-solid state at room temperature and is not easy to handle. Generally, the product form of a crystalline epoxy resin having a melting point of room temperature or higher is preferably a crystal grain (including a powder, the same applies hereinafter) in terms of blocking resistance and handleability. However, crystalline epoxy resins having supercooling properties can take various forms such as semi-crystalline solid, amorphous solid, amorphous semi-solid, and liquid in addition to crystalline solid at room temperature. For this reason, the granular product is formed by once making the resin into a crystalline solid and then pulverizing the resin, and the major point is how quickly the crystal nuclei of the resin can grow. The term "supercooling" as used herein means the property that crystallization does not occur sufficiently even when the resin melted at a melting point or higher is allowed to cool to a temperature below the melting point, and it exists as a viscous liquid or sticky solid. To do.

In the past, a method of crystallizing using a poor solvent has been generally used in the production of such a granular resin product. However, in this method, filtration and drying steps are indispensable and the number of steps is increased. In addition, if the solvent is not optimized, a large amount of loss may occur and the yield may decrease. In addition, a high temperature treatment is often required in the drying step, and the stability of the epoxy resin may be concerned, and the residual solvent may be a problem. On the other hand, as a method that does not use a solvent, a method has been adopted in which the resin taken out in a molten state is allowed to cool and allowed to stand until it is crystallized, and then subjected to processing such as pulverization to make a granular product. . According to this method, there is no problem as described above, but there is a problem that it takes a long time to crystallize and is economically disadvantageous.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a granular epoxy resin crystalline product having excellent productivity and economic efficiency and having a supercooling property.

[0005]

In view of such circumstances, the inventors of the present invention have made earnest studies, and as a result, found that the above object can be achieved by devising a crystallization process,
The present invention has been completed. That is, the present invention is characterized in that the crystalline epoxy resin in a supercooled state is kept in a temperature range of the glass transition temperature or higher and lower than the melting point, and a step of applying external force to grow crystal nuclei and a step of granulating are sequentially performed. This is a method for producing granular products of epoxy resin.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The epoxy resin used in the present invention is not particularly limited as long as it is a crystalline epoxy resin having supercooling property,
Examples thereof include those having a mesogen skeleton or those having a bisphenol skeleton and having a low molecular weight. Specific examples of these include those represented by the general formula (1) as those having a mesogenic skeleton.

[0007]

Embedded image And an epoxy resin represented by Among them, those having a structure in which the substituted phenylene groups at both ends of X are different, or those containing an oligomer component in which the self-polymerization reaction proceeds, and the like are suitable for applying the method of the present invention because they have high supercooling properties. . Examples of those having a bisphenol skeleton and having a low molecular weight are represented by the general formula (2)

[0008]

Embedded image Examples include those represented by. Further, these epoxy resins may be used as a mixture of two or more kinds.

In the method of the present invention, first, the crystalline epoxy resin in a supercooled state is maintained at a temperature not lower than the glass transition temperature and lower than the melting point, and an external force is applied to grow crystal nuclei. The glass transition temperature referred to here is the starting temperature of the endothermic peak based on the glass transition when the epoxy resin in a molten state above the melting point is rapidly cooled to liquid nitrogen temperature and differential scanning calorimetry is performed in the temperature rising mode. Indicates. The melting point refers to the melting point of the resin in a crystalline state. Applying external force to grow crystal nuclei is
This is because the crystal nucleus is grown by orienting the site (for example, mesogen skeleton) where the crystallinity is expressed by an external force while maintaining the mobility of the molecule. The temperature at this time is not particularly limited as long as it is within the above-mentioned temperature range, but the lower limit is preferably a temperature having a viscosity industrially practical for applying an external force. The viscosity is about 10,000 poise or less as one standard. If the viscosity is higher than this range, a large amount of energy is required to apply an external force, which is not practical. The upper limit temperature at this time is preferably about 10 ° C. lower than the melting point. At a temperature as close as possible to the melting point, crystallization is less likely to occur because the cohesive force of the molecules decreases. The state in which the crystal nuclei have grown or the state in which the crystallization is promoted herein means a state in which the resin becomes opaque, the resin loses its tackiness, or a state in which sufficient hardness is exhibited. Examples of the external force applied in the method of the present invention include shearing force,
Vibration, etc., electric motors, mixers, shakers,
An ultrasonic device, an extruder or the like can be used.

Next, the resin in which the crystal nuclei have grown is granulated or pulverized into a granular product in the granulating step. A known method can be used for granulation and pulverization, but if exemplified,
As the granulation method, a method of taking out the crystallized resin as a strand with a twin-screw extruder and then granulating it using a pelletizer, and as the crushing method, a jaw crusher, an impeller crusher, a hammer mill, a ball mill, a jet mill, a pin mill, etc. were used. Examples include crushing.

The epoxy resin granular product obtained by the method of the present invention is useful as an adhesive, a paint, an electric / electronic material such as an insulating material or a laminated board, and particularly for sealing an electronic component.

[0012]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. Reference Example 1 Synthesis of Raw Material Phenol-1 195.5 g (1.6 mol) of 2,6-xylenol (hereinafter abbreviated as 26XY) and 2-tercia were placed in a 2-liter four-necked flask equipped with a thermometer, a stirrer, and a condenser. 65.7 g (0.4 mol) g of l-butyl-5-methylphenol (hereinafter abbreviated as 3M6B) and 124.5 g (1.0 mol) of chloroacetaldehyde dimethyl acetal.
l) and 376 g of acetic acid, and stirred and dissolved.
Cooled down. Next, 122 g (1.2 mol) of concentrated sulfuric acid
Was added dropwise to 84 g of acetic acid over 3 hours at 10 ° C., and then the reaction system was kept at 25 ° C. for 6 hours, and stirring was continued at room temperature overnight. The temperature of the system was cooled to 5 ° C., and the precipitated crystals were separated by filtration. The crystals were washed six times with 500 g of water, and then vacuum dried at 40 ° C. for 8 hours to obtain crystals.

Reference Example 2 Synthesis of Raw Material Phenol-2 In a 2 liter four-necked flask equipped with a thermometer, a stirrer, and a condenser, 45.2% aqueous sodium hydroxide solution (245.2 g) was added.
And 552 g of N-methylpyrrolidone, and the inside was replaced with nitrogen. The solution was heated to 140 ° C. under a blanket of nitrogen. 225.6 g of the phenol intermediate obtained in Reference Example 1
And 676 g of N-methylpyrrolidone at 140 ° C.
The solution was added dropwise for 1.5 hours and kept at the same temperature for 2 hours. Thereafter, the reaction system was cooled to 60 ° C. and neutralized with 226 g of concentrated hydrochloric acid. After recovering the solvent under reduced pressure, the reaction mixture was discharged into 1,000 g of ion-exchanged water, and the precipitated crystals were separated by filtration.
After washing the crystals with 1,000 g of ion-exchanged water × 3 times,
For 8 hours to obtain crystals.

Reference Example 3 Synthesis of Epoxy 100 g of the raw material phenol obtained in Reference Example 2 was measured with a thermometer,
The reaction solution was charged into a reaction vessel equipped with a stirrer, a dropping funnel and a condenser equipped with a separation tube, and dissolved in epichlorohydrin (485.6 g) and dimethyl sulfoxide (243.1 g). While maintaining the inside of the reaction system at 43 torr, at a temperature of 48 ° C., 48.3%
61.71 g of caustic soda was continuously added dropwise over 5 hours.
During this period, while keeping the temperature at 48 ° C., the azeotropically distilled epichlorohydrin and water were cooled and liquefied, and the reaction was carried out while returning the organic layer into the reaction system. After completion of the reaction, unreacted epichlorohydrin was removed by concentration under reduced pressure, glycidyl ether containing by-product salt and dimethyl sulfoxide was dissolved in 644 g of methyl isobutyl ketone, and the by-product salt and dimethyl sulfoxide were removed by washing with water. After that, 160 ℃, 10
Methyl isobutyl ketone was distilled off under reduced pressure at torr to obtain the desired product (designated as XMCC-20E). The property of this resin immediately after being taken out was a brown viscous liquid at room temperature. The resin was once heated to 150 ° C. and melted, then rapidly cooled to liquid nitrogen temperature, weighed 10 mg, and subjected to differential scanning calorimetry (manufactured by Seiko Denshi KK, SSC5000 series / DSC200) at 10 ° C./mi.
The glass transition temperature was 5 ° C. when measured at a temperature rise condition of n. Further, when the melting point of the resin which had been left in a crystalline state was similarly measured, it was 130 ° C.

Reference Example 4 Synthesis of Epoxy In the case of Reference Example 1, 26XY122.2 g (1.0 mo)
l) and 3M6B164.3 g (1.0 mol) g were used, and the same operation was performed, and epoxidation was performed in the same manner as in Reference Example 4 to obtain the target product (designated as XMCC-50E). The property of this product immediately after taking out was a brown viscous liquid at room temperature. The glass transition temperature in a supercooled state and the melting point in a crystalline state of this resin measured in the same manner as in Reference Example 3 were 16 ° C and 90 ° C.

Examples 1 and 2 0.5 g of the epoxy resin obtained in Reference Examples 3 and 4 was once added to
It was heated to 0 ° C. to be in a molten state and allowed to cool as it was to obtain a viscous liquid resin at room temperature. 40-120 the resin in advance
Gelation tester heated to ℃ (manufactured by Nisshin Kagaku Co., Ltd.)
It was poured into the concave portion of and was stirred at a speed of 2 rotations per second using a glass rod. Table 1 shows the time required for the resin to crystallize at that time.

[0017]

[Table 1]

Example 3 The resin crystallized in Examples 1 and 2 was ground with a coffee mill grinder to obtain a powder of 0.5 mm or less.

Comparative Example 1 0.5 g of the epoxy resin obtained in Reference Example 3 was heated to 150 ° C. to be in a molten state and preheated to 140 ° C. Gelation tester (manufactured by Nisshin Kagaku Co., Ltd.) It was poured into the concave portion and stirred with a glass rod at a speed of 2 rotations per second, but it did not crystallize.

Comparative Example 2 0.5 g of the epoxy resin obtained in Reference Example 4 was heated to 150 ° C. to be in a molten state, and was preheated to 100 ° C. Gelation tester (manufactured by Nisshin Kagaku Co., Ltd.) It was poured into the concave portion and stirred with a glass rod at a speed of 2 rotations per second, but it did not crystallize.

Comparative Example 4 0.5 g of the epoxy resin obtained in Reference Examples 3 and 4 was heated to 150 ° C. to be in a molten state, and a gelling tester (manufactured by Nisshin Kagaku Co., Ltd.) at 23 ° C. (room temperature) was used. It was poured into the recess and left to stand. The time required for the resins to crystallize at that time was about one week for all the resins.

[0022]

EFFECT OF THE INVENTION The method for producing an epoxy resin granular product of the present invention is excellent in productivity and economy.

Claims (2)

[Claims] 1. A crystalline epoxy resin in a supercooled state is maintained in a temperature range of a glass transition temperature or higher and lower than a melting point, and a step of growing crystal nuclei by applying an external force and a step of granulating are sequentially performed. Method for producing granular products of epoxy resin. 2. The method for producing granular epoxy resin according to claim 1, wherein the crystalline epoxy resin in a supercooled state has a mesogenic skeleton or a bisphenol skeleton.