JPS6230145A - Epoxy resin composition for electronic material - Google Patents

Abstract

PURPOSE:A composition, obtained by incorporating a specific epoxy resin with a curing agent and curing catalyst, capable of increasing the curing rate and having improved fluidity characteristics, heat, water and chemical resistance, etc. CONSTITUTION:A composition obtained by incorporating an epoxy resin having <=0.01wt% hydrolyzable chlorine content and <=0.01wt% alpha-diol content with a curing and curing catalyst. Dicyandiamide is used as the curing agent and 2-ethyl-4-methylimidazole is used as the curing catalyst. The above-mentioned epoxy resin is obtained by reacting bisphenol A with epichlorohydrin by the two-stage method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an epoxy resin composition for electronic materials used for MNJ substrates of printed wiring boards, sealing of electronic components, and the like.

[Background technology] Epoxy resins are used in paints, adhesives, electronics (electrical), etc., depending on their excellent properties such as heat resistance, electrical properties, and adhesive properties of their cured products.
It is widely used in the fields of materials, composite materials, etc. In addition, the resin has good adhesion with a wide variety of other substances, has excellent water resistance, does not produce volatile substances that make the cured product porous, and has low shrinkage during curing. Because of its long-lasting properties, reliability as a product can be increased. Based on these excellent properties, epoxy resins have found wide use as electronics-related materials that require particularly high performance, and have come to be widely used in the electronics sector. However, because such high performance is required in the electronics sector, epoxy resin has not yet reached the point where it completely satisfies this requirement, and even though a huge amount of technical literature and patent literature has been accumulated since the past. However, the current situation is that a large amount of research and development is still being carried out.

In particular, the characteristics required of epoxy resins as electronic materials are heat resistance, water resistance, and chemical resistance of the cured product, and these characteristics are a? It is affected by the curing degree and cross-linking degree of the resin, and insufficient curing is not acceptable even if you make a mistake.Aside from productivity problems in the curing process, due to the characteristics of the cured product, epoxy resin is required to have a fast curing speed. Therefore, with regard to epoxy resins, much effort has been made to research the curing agent and the curing reaction mechanism. However, many elements regarding the curing reaction mechanism remain unclear, and the selection of curing agents has been made based on past experience rather than on theoretical grounds. As a result, organic amines and acid anhydrides continue to be the mainstream curing agents, and dicyanamides are still considered important as special curing agents.

[Objective of the Invention] The present invention has been made in view of the above-mentioned problems, and in order to improve the curing speed of epoxy resin, it focuses on the epoxy resin itself rather than the curing agent, which has been extensively researched since its arrival in the United States. The curing speed was improved by changing the process and selecting the resin itself.

[Disclosure of the Invention] Accordingly, the epoxy resin composition for electronic materials according to the present invention comprises an epoxy resin having a hydrolyzable chlorine content of 0601% by weight or less and an α diol content of o, oig 1% or less, The present invention is characterized in that it contains a curing agent and a curing catalyst, and the present invention will be described in detail below.

The present invention targets ordinary bis7er/-epichlorohydrin-based epoxy resins and brominated or chlorinated epoxy resins. There are more or less compounds containing chlorine and alpha diol. This is produced during the reaction between bisphenol A and epichlorohydrin. The present inventor has developed an epoxy resin containing hydrolyzable chlorine and α-diol.
'We have completed the present invention by discovering that when the amount of resin present falls below a certain level, the curing speed of the epoxy resin increases with a noticeable inflection point. The curing speed referred to here does not refer to the level at which various factors defined by so-called Deltime and Stroke Air are intertwined;
l Braid Analysis) Measurements - Measurement of viscoelasticity when glass fibers are impregnated with epoxy resin and cured and then returned by twisting - - Gradual increase in delta initiation temperature, ■ Gradual decrease in curing completion temperature, ■ Delpification This means that the activation energy of a substance is significantly reduced. This means that compared to regular epoxy resins that contain a high content of hydrolyzable chlorine and α-diol, although deltation is slow, once deltation begins, curing is completed rapidly, meaning that the flow time of the resin is short. For example, when molding a laminate using heat and pressure using this epoxy resin,
This means that the resin can be prevented from flowing out and the thickness deviation can be reduced. Further, by rapidly proceeding with curing in this manner, the heat resistance, water resistance, and chemical resistance of the cured product can be improved.

As mentioned above, hydrolyzable chlorine and α
The presence of groups other than epoxy groups such as diols, such as -CI groups and 10H groups, reduces the number of reaction active sites in the epoxy resin, slowing down the curing speed, and lowering the crosslinking density of the cured product, resulting in poor heat resistance. This is thought to have a negative effect on properties, water resistance, chemical resistance, etc., and the above effects can be obtained by reducing the amount of hydrolyzable chlorine and α-diol. Conceivable. In the epoxy resin, the content of hydrolyzable chlorine is 0.010% by weight or less based on the total amount of the epoxy resin, and the content of α diol is o, o i .

% by weight or less is necessary in order to achieve the above effects. These contents are o and o i respectively
When the content decreases to 0% by weight, the above effects appear with a noticeable change point.

In order to obtain an epoxy resin with a low content of hydrolyzable chlorine and α-diol, the epoxy resin is prepared by reacting bis7er7-A and epichlorohydrin in a two-step process. It is better. That is, in preparing epoxy resin, generally 72/-
A one-step method is used in which the polymer A and epichlorohydrin are sequentially reacted in the presence of an alkali to increase the molecular weight, but in this -killing method, an epoxy resin with a high content of hydrolyzable chlorine and α-diol is prepared. Ru. In contrast, in the first step, bisphenol A and epichlorohydrin are reacted in the presence of an alkali to produce a low molecular weight solid epoxy resin, and in the second step, bisphenol A is added to the low molecular weight epoxy resin produced in the first step. The two-step method of preparing a high-molecular-weight epoxy resin by adding and reacting can produce an epoxy resin with a low content of hydrolyzable chlorine and α-diol.

In this two-step method, the −751st reaction is generally
About 3.5 hours at a reaction temperature of about 9 to 19 degrees Celsius (2,
The second stage reaction is carried out at a reaction temperature of about 200° C. for a reaction time of about 90 minutes. However, in this case, the content of hydrolyzable chlorine is 0.
Although it is possible to obtain an epoxy resin with an α-diol content of up to about 0.02% by weight and an α-diol content of about 0.03% by weight, it is not sufficient to reduce the content of hydrolyzable chlorine and α-diol. do not have.

Therefore, the second-stage reaction is performed at a lower temperature and longer reaction time than the reaction temperature and reaction time during the second-stage reaction in the conventional general two-stage method described above, that is, at a low temperature and for a long time. It is preferable to use an epoxy resin prepared by this method.

In other words, the first stage reaction can be carried out under the same conditions as the first stage of the conventional two-stage method, for example, about 15 moles of bisphenol A, about 1.5 moles of epichlorohydrin, and further hydroxylation as an alkali. About 3 moles of sodium are charged in each, and the reaction is carried out for about 3.5 hours (2.5 to 4.5 hours) at a reaction temperature of 99° C. to 19° C. to obtain a low molecular weight solid epoxy resin. Bis7el/A is added to the low molecular weight epoxy resin obtained in the first step, and the reaction temperature and reaction time are 200°C and 90 minutes, which are the second step reaction conditions in the conventional two-step method. Temperature lower than 120~150℃, long time 18
A second stage reaction is carried out at 0 to 360°C for a long time at low temperature to obtain an epoxy resin with a high molecular weight. If added in the second stage reaction, the molecular weight of the target epoxy resin can be adjusted by adjusting the blending amount of Suphenol A, but usually the molar amount of (bisphenol A/low molecular weight epoxy resin produced in the first stage) is The ratio is 15
It is preferable to set the following. By performing such a second stage reaction at a low temperature and a long time, the contents of hydrolyzable chlorine and α-diol can be reduced to 0.01% each.
It is possible to prepare epoxy resins with a weight of 0.5 or less.

In the present invention, an epoxy resin composition is prepared by blending a curing agent and a curing catalyst into an epoxy resin in which the content of hydrolyzable chlorine and α-diol is 0.010% by weight or less, respectively. It is used for electronic materials such as plate laminates and sealing resin materials for other electronic components. Uni uses dicyandiamide as a hardening agent.
2-ethyl-4-methylimidazole can be used as a curing catalyst. The amount of dicyandiamide added is 0.
．． The amount of 2-ethyl-4-methylimidazole added is preferably about 10 mol% or less, and the amount of dicyandiamide and 2-ethyl-4-methylimidazole is preferably about 2 to 1.5 equivalents. For example, an epoxy resin varnish can be prepared by dissolving it in a solvent such as formamide and adding it to an epoxy resin.

Next, the present invention will be specifically explained using examples.

15 mol of K192 bisphenol A, 1 mol of epichlorohydrin
．． Prepare 5 mol and 3 mol of sodium hydroxide,
The first stage reaction was carried out at 10°C for 3.5 hours, and then bisphenol A was added to this reaction product so that the molar ratio of (bisphenol A/low molecular weight epoxy resin produced in the first stage) was 10. In addition, a second reaction was carried out at 135°C for 270 minutes to produce 11li of epoxy resin.

Add 0.41 dicyandiamide to this epoxy resin.
equivalent, 2-ethyl-4-methyl, 0.9 guzol
These were taken and dissolved in methyl cellosolve to a concentration of 4 mol %, and then added and mixed with the above epoxy resin to prepare an epoxy resin composition for electronic materials.

Dog No. 1 - The content of hydrolyzable chlorine and α-diol varies slightly from production batch to batch, so in order to confirm the amount of this variation, an epoxy resin was prepared in the same manner as in Example 1, and an experiment was carried out. A face of an epoxy resin composition for electronic materials was prepared in the same manner as in Example 1.

The first reaction was carried out in the same manner as in Example 1, and the epoxy resin was prepared in the same manner as in Example 1, except that the second reaction was carried out at a reaction temperature of 200°C and a reaction time of 90 minutes. A two-step method was used to prepare an epoxy resin composition for electronic materials in the same manner as in Example 1.

Epoxy resins prepared according to Examples 1, 2 and Comparative Example 1 above, and by conventional one-step method? Regarding the RH-treated epoxy resin (Comparative Example 2), the contents of hydrolyzable chlorine and α-diol are shown in Table 1.

In addition, the epoxy resin composition for electronic materials obtained in Examples 1 and 2 and Comparative Example 1, and the epoxy resin composition for electronic material obtained in the same manner as in Example 1 using the epoxy resin of Comparative Example 2. The gel fraction, activation energy, and delta initiation temperature were measured for each, and the results are shown in Table 2. Here, the del fraction is measured at 180℃ x 3
This was done by baking for 0 minutes to create a film, which was then extracted with chloroform. In addition, the deltation initiation temperature is the temperature at which the stiffness modulus under heat starts to increase rapidly in the TBA curve, that is, the temperature at which the stiffness modulus under heat starts to increase rapidly as the curing reaction progresses.
) As shown in Table 2 and Table 1, in Examples 1 and 2, in which epoxy O (51! It is confirmed that the contents of hydrolyzable chlorine and α-diol are low at 0.01% by weight or less.In addition, as shown in Table 2, the content of hydrolyzable chlorine and α-diol is low, at 0.01% by weight or less.
Examples 1 and 2, each containing a diol content of 0.01% by weight or less, have a high del fraction and are highly reactive, have a low activation energy, rapidly proceed with curing, and have a low deltation initiation temperature. It is confirmed that the flow time of the resin can be shortened due to the high flow rate.

[Effect of the invention 1 As described above, the epoxy resin composition for electronic materials according to the present invention has a hydrolyzable chlorine content of 0.01% by weight or less and an α-diol content of 0.01% by weight or less. Because it is a mixture of epoxy resin, curing agent and curing catalyst, it eliminates the effects of hydrolyzable chlorine and α-diol,
It is possible to accelerate the curing speed from the start of curing to the completion of curing, and it is possible to improve properties such as flow characteristics, heat resistance, water resistance, and chemical resistance required for electronic materials. .

Claims (2)

[Claims] (1) A curing agent and a curing catalyst are blended into an epoxy resin having a hydrolyzable chlorine content of 0.01% by weight or less and an a-diol content of 0.01% by weight or less. Epoxy resin composition for electronic materials. (2) The curing agent is dicyandiamide and the curing catalyst is 2
2. The epoxy resin composition for electronic materials according to claim 1, which is ethyl-4-methylimidazole.