JP2015172136A - Epoxy resin-based composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin-based composition having low viscosity at an early stage of heating but having a quick thermal time hardness rising after the hardening started during heat hardening, with a steep curing behavior (hereafter referred to as a pan bottom curve), but excellent in safety.SOLUTION: To provide 1, 2-bis (diphenylphosphino) -acetylene compound as expressed by the following formula (1) as a hardening accelerator, and to provide an epoxy resin-based composition containing at least epoxy resin, a phenol resin-based curative, and a compound as expressed by the following formula (1).

Description

The present invention relates to an epoxy resin composition having improved curing behavior.

  Conventionally, when an epoxy resin composition is used, a molded article having excellent mechanical, chemical and electrical properties can be obtained. Therefore, an epoxy resin composition is in the form of an adhesive, a paint, and a casting material. It is widely used for various electrical parts such as coils, capacitors and printed circuit boards, and for insulation sealing of semiconductor elements and integrated circuits.

Among the applications described above, in the field of semiconductor device insulation sealing, the demand for higher integration of semiconductor devices is high, and the structure of semiconductor packages continues to advance.
For this reason, the performance of the epoxy resin composition as the sealing material is also required to be superior.

  For example, when sealing a semiconductor element using an epoxy resin-based composition for sealing, the hardness at the beginning of heating is rapid after the low viscosity at the initial stage of heating and the curing starts at the time of thermosetting, and a steep curing behavior ( Hereinafter, a resin composition having a pan-bottom viscosity curve) is required. And in order to perform a short time shaping | molding, the research which improves the hardness at the time of hardening at the time of hot is performed (refer patent document 1, patent document 2).

  Under such circumstances, phosphorus-based or imidazole-based curing accelerators are known as epoxy resins, but it is possible to obtain a cured product with high curing power and high electrical reliability. Phosphorus is generally known as a possible curing accelerator.

  Tris (4-methylphenyl) phosphine (see Non-patent Document 1), diphosphines (see Patent Document 3 and Patent Document 4), and phosphonium thiocyanates (Patent Documents 5 and 6) 2 and 3), and phosphonium dicyanamides (see Patent Documents 7 and 8 and Non-Patent Document 4).

  However, these compounds exhibit a certain degree of curing power during the curing reaction of the epoxy resin composition, but are not sufficient from the viewpoint of a pan-bottom viscosity curve, and there is room for improvement in the curing behavior. Furthermore, since phosphonium thiocyanates and phosphonium dicyanamides are classified as deleterious substances in the Poisonous and Deleterious Substances Control Law, there are safety problems and their use is limited. In particular, for phosphonium dicyanamides, the raw materials potassium dicyanamide and sodium dicyanamide are not widely distributed, and there is a difficulty in terms of stable supply.

  In addition, it is known that the resin material which mix | blended the 1, 2-bis (diphenylphosphino) acetylene compound represented by following formula (1) becomes a high refractive index (refer patent document 9). It has not been known so far as being effective as a resin curing accelerator.

Japanese Patent No. 3543854 Japanese Patent No. 5386837 JP 61-053321 A Japanese Patent No. 3876944 JP 2009-298960 A JP 2010-209150 A JP 2012-018414 A JP 2012-017292 A WO 2004/074884

“Network polymer” published by Japan Synthetic Resin Industry Association (2012), Vol. 33, no. 3, p123-129 Epoxy resin compounding design and high functionality, published by Science & Technology (2008), "Chapter 2 Section 5 Properties and Usage of Phosphoric Curing Accelerators" 59th Network Polymer Lecture Meeting, Abstracts of “Hardening Properties of Phosphorus Curing Accelerators—Phosphonium Thiocyanates” (2009) 60th Network Polymer Lecture Meeting, Abstracts of Curing “Curing Properties of Phosphorus Curing Accelerators—Phosphonium Dicyanamide” (2010)

  The present invention seeks to solve the problems associated with the prior art as described above. In other words, the resin composition has low viscosity in the initial stage of heating, rapid rise in hardness when heated after curing begins, and steep curing behavior (hereinafter referred to as pan-bottom viscosity curve), but also excellent safety. Is to provide things.

  In view of such a situation, the present inventors have intensively studied. As a result, if a 1,2-bis (diphenylphosphino) acetylene compound represented by the following formula (1) is blended as a curing accelerator, a resin composition whose curing behavior is a pan-bottom viscosity curve is obtained, Thus, the present compound was found to be excellent in safety because LD50, which is an index of acute oral toxicity, is larger than 300 mg / kg, and the present invention was completed.

  That is, the gist of the present invention is as follows.

[1] A curing accelerator for epoxy resins containing a 1,2-bis (diphenylphosphino) acetylene compound represented by the above formula (1) as an active ingredient.
[2] An epoxy resin composition comprising at least an epoxy resin, a phenol resin curing agent, and a 1,2-bis (diphenylphosphino) acetylene compound represented by the above formula (1).
[3] The epoxy resin composition according to [2], further comprising an inorganic filler.
[4] An epoxy resin-based cured product obtained by curing the composition according to any one of [2] and [3].

  The epoxy resin-based composition containing the curing accelerator for epoxy resin of the present invention as a component has a particularly preferable curing behavior as compared with the case of using a conventional curing accelerator, and is excellent in safety. Very useful.

The figure which shows the hardness measurement result at the time of the hardening reaction in 150 degreeC.

Hereinafter, the present invention will be described in detail.
The epoxy resin composition according to the present invention includes at least an epoxy resin, a phenol resin curing agent, and a 1,2-bis (diphenylphosphino) acetylene compound represented by the following formula (1). It is an epoxy resin composition.

  In the present invention, the epoxy resin composition refers to a mixture obtained by uniformly mixing the epoxy resin, the phenol resin curing agent, and the curing accelerator, and the epoxy resin cured product is a specific condition in the epoxy resin composition. By applying heat underneath, the epoxy resin loses its fluidity and refers to a cured solid.

<Epoxy resin>
It does not specifically limit as an epoxy resin, It is possible to use a general purpose epoxy resin, and if it contains two or more epoxy groups in a molecule | numerator, it can be used without a restriction | limiting. For example, phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl aralkyl type epoxy resin, dihydroanthracene type epoxy resin, naphthalene type tetrafunctional epoxy resin, trisphenol methane type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy Examples thereof include resins and alicyclic epoxy resins. These epoxy resins can be used alone or in admixture of two or more. Further, it may be used as it is, or it may be used by appropriately adding a solvent, an additive or the like.

<Phenolic resin curing agent>
It does not specifically limit as a phenol resin type hardening | curing agent, A general purpose phenol resin can be used, For example, a phenol novolak resin, a cresol novolak resin, a phenol aralkyl resin, a biphenyl aralkyl type phenol resin etc. are mentioned. These resins may be used as they are as a curing agent, or may be used as a curing agent composition by appropriately adding a solvent, an additive, or the like.

<Curing accelerator>
A 1,2-bis (diphenylphosphino) acetylene compound represented by the formula (1) is included as a curing accelerator.
The 1,2-bis (diphenylphosphino) acetylene compound is a known substance, and a commercially available product can be obtained and used.

  The curing accelerator for epoxy resin according to the present invention may contain a compound that appropriately accelerates curing of the epoxy resin, in addition to the 1,2-bis (diphenylphosphino) acetylene compound.

<Epoxy resin composition>
The epoxy resin-based composition can contain various known inorganic fillers in order to reduce the linear expansion coefficient. Examples of the inorganic filler include fused silica, crystalline silica, alumina, and aluminum nitride. They may be surface-treated with a coupling agent such as a silane coupling agent.

  In addition, the well-known additive added to an epoxy resin type composition may be contained. Examples of the additive include an ion trap agent, a release agent, and a pigment such as carbon black. Moreover, resin other than an epoxy resin can also be included.

  Of the epoxy resin-based composition, the content of the 1,2-bis (diphenylphosphino) acetylene compound according to the present invention is 0.5 to 10 parts by weight with respect to 100 parts by weight of the curable epoxy resin. It is preferable. This is because if the content is less than 0.5 parts by weight, the curing accelerating effect may not be sufficiently exhibited, and if the content is more than 10 parts by weight, the storage stability of the composition is impaired. Considering the curing acceleration effect more strictly, the content is more preferably 1 to 5 parts by weight.

  The content of the phenol resin-based curing agent is determined in consideration of the equivalent ratio between the epoxy equivalent in the epoxy resin and the hydroxyl equivalent of the phenol resin. In general, the content of the phenol resin-based curing agent is determined so that the equivalent ratio of epoxy equivalent to hydroxyl equivalent is 1: 1.

  The epoxy resin composition of the present invention can be prepared by mixing each of the above components at the predetermined ratio. As a preferable preparation method, it is preferable to heat and cool a mixture of a phenol resin-based curing agent and a curing accelerator, subsequently mix with an epoxy resin, and heat and then cool.

  The reason why the mixture of the phenol resin-based curing agent and the curing accelerator is heated is to reduce the viscosity of the phenol resin-based curing agent to facilitate mixing and to stir the curing agent and the curing accelerator to be uniform. It is. Here, if the heating temperature is preferably 100 ° C. to 180 ° C., it can be easily mixed.

  Before mixing with the epoxy resin, it is preferable to cool the mixture in advance, as described above, it is necessary to accurately measure the mixture so that the equivalent ratio of epoxy equivalent to hydroxyl equivalent is 1: 1. This is because it is easy to handle.

  An epoxy resin composition is obtained by heat-mixing a cooled mixture of a phenol resin curing agent and a curing accelerator with an epoxy resin.

  Moreover, each component of a phenol resin type hardening | curing agent, a hardening accelerator, and a curable epoxy resin may be mixed at once in each mixing process, or may be mixed little by little in several steps. Similarly, when the above-mentioned solvent, additive, inorganic filler, and the like are mixed, they can be mixed once or divided into a plurality of times at an arbitrary time.

  In addition, when mixing a phenol resin curing agent and a curing accelerator or mixing with an epoxy resin, a kneader such as a roll or a kneader may be used to facilitate uniform stirring and mixing. preferable.

<Epoxy resin-based cured product>
The epoxy resin-based cured product can be obtained by heating the above-described epoxy resin-based composition of the present invention at a curing temperature of about 80 to 250 ° C. and a curing time of 30 seconds to 15 hours.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Test Examples, but the present invention is not limited thereto.

<Example 1>
To 214 parts by weight of phenol resin curing agent MEH-7851M (hydroxyl equivalent 214, manufactured by Meiwa Kasei Co., Ltd.), 7.1 parts by weight of curing accelerator 1,2-bis (diphenylphosphino) acetylene is added at 150 ° C. The mixture was stirred and mixed with heating for 2 minutes, and then cooled to room temperature. To this was added 280 parts by weight of an epoxy resin NC-3000 (epoxy equivalent 274, manufactured by Nippon Kayaku Co., Ltd.), stirred and mixed with heating at 120 ° C. for 2 minutes, and then cooled to room temperature to obtain an epoxy resin composition. It was. Here, the equivalent ratio of epoxy equivalent to hydroxyl equivalent is 1.0.

<Comparative Example 1>
An epoxy resin composition in the same manner as in Example 1 except that 3.4 parts by weight of tris (4-methylphenyl) phosphine was used instead of 7.1 parts by weight of 1,2-bis (diphenylphosphino) acetylene. I got a thing.

<Comparative Example 2>
In the same manner as in Example 1, except that 3.6 parts by weight of 1,2-bis (diphenylphosphino) ethane was used instead of 7.1 parts by weight of 1,2-bis (diphenylphosphino) acetylene. A resin-based composition was obtained.

<Comparative Example 3>
An epoxy was prepared in the same manner as in Example 1 except that 5.1 parts by weight of 1,4-bis (diphenylphosphino) butane was used instead of 7.1 parts by weight of 1,2-bis (diphenylphosphino) acetylene. A resin-based composition was obtained.

  About the characteristic (pan-bottom type viscosity curve) of the epoxy resin composition obtained in each Example and Comparative Example, the viscosity at the initial stage of heating was evaluated using a rheometer, and the rise in hardness at the time of curing was evaluated using a durometer. . From the viewpoint of the pan-bottom viscosity curve, it is preferable that the initial stage of heating has a low viscosity and a rapid rise in hardness when heated after the start of curing at the time of thermal curing, and that the time required to reach a steep and constant degree of curing is fast. Details of the evaluation method are shown below.

[Gel time measurement]
According to the gelation time measurement method described in JIS K 6910, the steel sheet temperature was 150 ° C., and the gel time (GT) of the epoxy resin compositions obtained in Example 1 and Comparative Examples 1 to 3 was GT manufactured by Nisshin Kagaku Co. -Measured using D.
In addition, the Example and comparative example which mix | blended each hardening accelerator matched the gel time by adjusting the compounding quantity of a hardening accelerator.

(Viscosity measurement)
The viscosities of the epoxy resin compositions obtained in Example 1 and Comparative Examples 1 to 3 were measured over time with a rheometer. As the rheometer, a cone plate type rheometer RC20-CPS manufactured by Rheotech Co., Ltd. is used, and the cone plate is C25-2. The rotational speed is 6.67 rpm and the shear rate is 20 (1 / s). Measurements were made on a 150 ° C. hot plate.

[Heat hardness measurement]
The hot-time hardness of the epoxy resin-based compositions obtained in Example 1 and Comparative Examples 1 to 3 was measured over time using a durometer. As a durometer, a durometer GS-720G (JIS K6253, JIS K7215 compliant, type D) manufactured by Teclock was used, and an epoxy resin composition was measured on a 150 ° C. hot plate.

[Acute oral toxicity test]
The safety test of the curing accelerator used in Example 1 and Comparative Examples 1 to 3 was performed according to OECD TG423 (toxicity rating method) using mice.

  Table 1 shows the gel time measurement results at 150 ° C. of the epoxy resin compositions obtained in Example 1 and Comparative Examples 1 to 3 and the viscosity at the initial curing corresponding to the gelation time. The results are shown in FIG.

  In Table 1, “DPPA” represents 1,2-bis (diphenylphosphino) acetylene, “TPTP” represents tris (4-methylphenyl) phosphine, and “DPPE” represents 1,2-bis (diphenyl). Phosphino) ethane and "DPPB" denotes 1,4-bis (diphenylphosphino) butane.

  As shown in Table 1, when the viscosity measurement results at the initial stage of curing at 150 ° C. were observed, a difference was observed in the viscosity at the initial stage of curing in each example. Specifically, it was found that the epoxy resin composition of Example 1 had a lower viscosity at the initial stage of curing than Comparative Examples 1 to 3.

  Further, when the measurement result of the hardness at the time of the curing reaction at 150 ° C. shown in FIG. Specifically, in the epoxy resin composition of Example 1, the time to reach hardness 20 is about 420 seconds and compared with Comparative Examples 1 to 3, the fastest increase in hot hardness during the curing reaction, It became steep.

  That is, the epoxy resin-based composition of the present invention has a resin composition with a low viscosity at the initial stage of heating and a sharp rise in hardness at the time of curing compared to the case of using a conventional phosphorus-based curing accelerator. Obviously, it exhibits excellent curing properties.

  Moreover, the results of the acute oral toxicity test of the curing accelerator used in Example 1 and Comparative Examples 1 to 3 were all 300> (mg / Kg), confirming that they were equivalent to ordinary products.

  The epoxy resin-based composition of the present invention is clearly excellent in curing characteristics, and on the other hand, since it is also excellent in safety, for example, in resin sealing of various small electric / electronic parts and semiconductor parts. Useful.

Claims (4)

A curing accelerator for epoxy resins comprising a 1,2-bis (diphenylphosphino) acetylene compound represented by the following formula (1) as an active ingredient.

An epoxy resin composition comprising at least an epoxy resin, a phenol resin curing agent, and a 1,2-bis (diphenylphosphino) acetylene compound represented by the formula (1) according to claim 1. The epoxy resin composition according to claim 2, further comprising an inorganic filler. An epoxy resin-based cured product obtained by curing the composition according to claim 2.

Images