JP2010126713A - Method and vessel for storing epoxy resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for storing an epoxy resin composition containing a curing agent over the long period of time without deteriorating characteristics of the epoxy resin composition. <P>SOLUTION: In the method for storing the epoxy resin composition containing epoxy resin and the curing agent in a vessel, a support containing boron nitride is arranged in the vessel. The storing vessel including the support containing boron nitride is also provided for storing the epoxy resin composition containing the epoxy resin and the curing agent. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for storing an epoxy resin composition, and more particularly, an epoxy resin composition used by impregnation or casting to insulate a coil or the like incorporated in a rotating machine mounted on an electric motor or a generator. It relates to the storage method.

  In general, coils used in electric machines such as electric motors and generators used in vehicles such as railway vehicles, automobiles, forklifts, aircraft and various industrial machines, or in rotating machines mounted on vibrators, etc. In order to improve properties, electrical characteristics, strength, etc., a treatment is performed in which the coil is impregnated with an insulating resin and heat-cured. Among insulating resins, epoxy resins are frequently used because they have excellent adhesive properties, small cure shrinkage, and the cured products have excellent electrical and mechanical properties (for example, JP, 2000-297204, A (patent documents 1) reference).

  Conventionally, an insulating resin of a rotating machine coil such as a generator generally uses a resin system that cures an epoxy resin excellent in electrical and mechanical properties of the cured product with an acid anhydride (for example, JP 2000-239356 A (Patent Document 2)).

Excess insulating resin after coil impregnation is usually returned to the storage tank and reused repeatedly. However, it exists in the epoxy resin and the curing reaction between the free acid and the epoxy resin generated by the hydrolysis reaction of the acid anhydride. Since the curing reaction of the hydroxyl group to be cured and the amine or acid anhydride contained in the curing agent proceeds, the coil cannot be sufficiently impregnated with the resin due to an increase in the viscosity of the resin, and long-term storage and reuse are difficult (short pot life) ). In addition, it is conceivable to avoid the reuse and mix and mix only the minimum amount of use each time. However, the workability is reduced and the resin that has become unusable must be discarded. The problem is that waste resin increases.
JP 2000-297204 A JP 2000-239356 A

  An object of this invention is to provide the storage method which can be stored for a long time, without deteriorating the characteristic of the epoxy resin composition containing a hardening | curing agent.

  The present invention is a storage method for storing an epoxy resin composition containing an epoxy resin and a curing agent in a container, wherein the container has a support provided with boron nitride in the container.

  In the present invention, the curing agent is preferably an acid anhydride curing agent. Moreover, it is preferable that the said several support body is immersed in the epoxy resin composition in a container.

  Furthermore, the present invention relates to a storage container for an epoxy resin composition containing an epoxy resin and a curing agent, wherein the storage container has a support provided with boron nitride.

  Since the storage method and the storage container of the present invention have a support provided with boron nitride in the container, it is possible to prevent reactions such as curing of the epoxy resin composition, and thus there is a storage stabilization effect, The pot life of the epoxy resin composition can be extended. In addition, since a large amount of the epoxy resin composition can be blended, mixed, and stored at a time, insulation treatment of a rotating electric coil or the like can be performed efficiently. Furthermore, it has the outstanding effect that waste resin can be reduced.

(Embodiment 1)
FIG. 1 shows an example of the present invention. In the present embodiment, a support 3 containing boron nitride powder is provided in a container 1 having an epoxy resin composition 2 containing an epoxy resin as a main agent and a curing agent. The wall surface of the support 3 has holes through which the epoxy resin composition can pass into the support, and the epoxy resin in the container 1 is stored in the support 3 through the holes in the wall of the support 3. It is possible to contact boron nitride. The support 3 is provided with a support bar 4 as a fixing member to the outside of the container.

  According to such a configuration, the epoxy resin and boron nitride come into contact with each other, so that the effect of significantly extending the pot life is exhibited. This is cured by an acid-base interaction between the oxygen atom of the hydroxyl group in which the epoxy group of the epoxy resin is opened and the boron atom of boron nitride, or a hydrogen bond between the hydrogen atom of the hydroxyl group and the nitrogen atom of boron nitride. This is considered to be an effect due to the ability to suppress the activity of the hydroxyl group that can be the starting point of the reaction.

  In general, epoxy resins have an epoxy resin having a dihydroxyl structure in which an epoxy group is ring-opened (see FIG. 3) as a trace amount of impurity components (see Japanese Patent Application Laid-Open No. 60-79031). It is considered that it is easy to cause a curing reaction with contained amines and acid anhydrides (Hiraki Kakiuchi, “New Epoxy Resin”, Shosodo, 1988).

  The epoxy resin composition which is the object of the storage method of the present invention contains (A) an epoxy resin and (B) a curing agent. The epoxy resin composition may further contain a diluent such as styrene, a curing catalyst, and a curing accelerator used in this field.

  (A) The epoxy resin contains an epoxy compound having two or more epoxy groups per molecule. As such an epoxy compound, any compound can be used as long as it has two or more three-membered rings composed of two carbon atoms and one oxygen atom in one molecule and can be cured. It is not particularly limited. Specific examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenol type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A type novolac type epoxy resin, bisphenol F. Type novolac epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, isocyanurate type epoxy resin, salicylaldehyde novolak type epoxy resin, etc. Diglycidyl etherified products of bifunctional phenols, diglycidyl etherified products of bifunctional alcohols, their halides, hydrogenated products, etc. Luo may be used in combination of several kinds.

  (B) The curing agent is a compound having reactivity with the epoxy group of the above epoxy resin, and any of those used in this field can be used, but depending on the purpose of the epoxy resin composition, an acid anhydride It is preferable to use an amine-based or phenol-based curing agent. Phenol curing agents are preferred when high moisture resistance and hydrolysis resistance are required, and amine curing agents and cationic polymerization catalysts that are liquid at room temperature are preferred when low temperature curing is required. When viscosity is required, an acid anhydride curing agent is preferred. Among these, it is particularly preferable to apply the storage method according to the method of the present invention to an epoxy resin composition containing an acid anhydride curing agent because the storage stabilization effect is high.

  The acid anhydride used for the acid anhydride curing agent is not particularly limited as long as it is an acid anhydride capable of curing reaction with the epoxy resin. Specific examples of the acid anhydride include hexahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, 4-methyltetrahydrophthalic anhydride, methyl anhydride Nailsic acid, methylnorbornane-2,3-dicarboxylic acid anhydride, norbornane-2,3-dicarboxylic acid anhydride, dodecenyl succinic anhydride, Diels-Alder reaction product of decatriene such as α-terpinene and alloocimene and maleic anhydride And their hydrogenated products, as well as structural isomers or geometric isomers of these acid anhydrides, and mixtures and modified products thereof. Among these, 4-methylhexahydrophthalic anhydride, 3- Methyl tetrahydrophthalic anhydride and methyl nadic anhydride are preferred.

  As a compounding quantity of an acid anhydride, 0.5-1.5 equivalent is desirable with respect to the total equivalent 1 of the epoxy group resulting from the epoxy resin which has a 2 or more epoxy group in a molecule | numerator. When the amount is less than 0.5 equivalent, the viscosity increases due to a decrease in the proportion of the acid anhydride which is a low viscosity component in the thermosetting resin composition. In addition, the heat resistance and mechanical properties of the cured product are reduced. If it exceeds 1.5 equivalents, the heat resistance and mechanical properties of the cured product will deteriorate.

  As the shape of the boron nitride 5 used in the present invention, it is preferable to use a powder, and any particle size can be used. The amount of boron nitride added is preferably in the range of 0.01 to 200 parts by weight, more preferably less than 50 parts by weight, with respect to 100 parts by weight of the total of the epoxy resin of component (A) and component (B). is there. If it is 50 parts by weight or more, the occupied volume of boron nitride stored in the support increases, so that the allowable amount of resin in the container is reduced and workability is inferior.

  Further, it is preferable to provide a plurality of supports in the container because the storage stabilization effect can be easily obtained.

  The material of the support 3 is not particularly limited as long as it does not degrade the resin characteristics by being dissolved in the epoxy resin composition, and examples thereof include stainless steel, nylon, and polypropylene.

  The shape of the support 3 is a size that can be accommodated in the container 1 and is not particularly limited as long as it has a space for accommodating the boron nitride. And the like, and a porous carrier, which is characterized in that the epoxy resin composition can come into contact with boron nitride.

  When the support 3 is a container having a porous wall, the diameter is not limited as long as the size of the porous is larger than the size of one molecule of epoxy resin can pass through, but the number of holes is large. Since the movement of the epoxy resin into the support becomes easier, it is desirable that the total sum of the hole areas per unit area of the wall surface is large.

  The support bar 4 is a member for supporting the support 3 and is fixed to a storage container, a member outside the container, or the like. The material of the support bar 4 is not particularly limited as long as it does not dissolve in the epoxy resin composition and does not deteriorate the resin characteristics, and examples thereof include stainless steel, nylon, and polypropylene.

(Embodiment 2)
As shown in FIG. 2, one or more supports 3 are provided and are immersed in a container. According to this structure, even when the volume of the epoxy resin composition is large with respect to the volume of boron nitride accommodated in the support and the diffusion of the epoxy resin composition in the container is small, the support exists at a plurality of positions. This makes it easier to obtain a storage stabilization effect.

Next, examples of the present invention will be shown, but the present invention is not limited thereto.
(Examples 1-6)
Bisphenol A type epoxy resin [trade name: JER828, manufactured by Japan Epoxy Resin Co., Ltd.] 29 parts by weight, methyltetrahydrophthalic anhydride [trade name: QH-200, manufactured by Nippon Zeon Co., Ltd.] 21 parts by weight, styrene monomer [ Product name: Styrene monomer, manufactured by Wako Pure Chemical Industries, Ltd.] An epoxy resin composition 1L having 50 parts by weight was placed in a 2 L sample bottle with a lid. A polypropylene cloth filter [trade name: filter with string, ASONE Co., Ltd.] with a predetermined amount of boron nitride shown in Table 1 is equally divided into the above three filters and stored in the upper part of the filter. What was closed was soaked.

(Comparative Example 1)
Bisphenol A type epoxy resin [trade name: JER828, manufactured by Japan Epoxy Resin Co., Ltd.] 29 parts by weight, methyltetrahydrophthalic anhydride [trade name: QH-200, manufactured by Nippon Zeon Co., Ltd.] 21 parts by weight, styrene monomer [ Product name: Styrene monomer, Wako Pure Chemical Industries, Ltd.] Comparative Example 1 was prepared by putting 1 L of an epoxy resin composition with 50 parts by weight in a 2 L sample bottle with a lid.

(Comparative Example 2)
Bisphenol A type epoxy resin [trade name: JER828, manufactured by Japan Epoxy Resin Co., Ltd.] 29 parts by weight, methyltetrahydrophthalic anhydride [trade name: QH-200, manufactured by Nippon Zeon Co., Ltd.] 21 parts by weight, styrene monomer [ Product name: Styrene monomer, manufactured by Wako Pure Chemical Industries, Ltd.] An epoxy resin composition 1L having 50 parts by weight was placed in a 2 L sample bottle with a lid. A polypropylene cloth filter [trade name: filter with string, ASONE Co., Ltd.] having a predetermined amount of alumina shown in Table 1 [trade name: DAW05, manufactured by Denki Kagaku Kogyo Co., Ltd.] The two filters were equally divided and stored, and the upper part of the filter was closed.

(Comparative Example 3)
Bisphenol A type epoxy resin [trade name: JER828, manufactured by Japan Epoxy Resin Co., Ltd.] 29 parts by weight, methyltetrahydrophthalic anhydride [trade name: QH-200, manufactured by Nippon Zeon Co., Ltd.] 21 parts by weight, styrene monomer [ Product name: Styrene monomer, manufactured by Wako Pure Chemical Industries, Ltd.] An epoxy resin composition 1L having 50 parts by weight was placed in a 2 L sample bottle with a lid. There is a polypropylene cloth filter having an opening in the upper part [trade name: filter with string, manufactured by ASONE Co., Ltd.] and a predetermined amount of silica product name shown in Table 1: FB-5D, manufactured by Denki Kagaku Kogyo Co., Ltd.] Was stored in three equal parts of the filter, and the filter was closed and the upper part of the filter was closed.

(Comparative Example 4)
Bisphenol A type epoxy resin [trade name: JER828, manufactured by Japan Epoxy Resin Co., Ltd.] 29 parts by weight, methyltetrahydrophthalic anhydride [trade name: QH-200, manufactured by Nippon Zeon Co., Ltd.] 21 parts by weight, styrene monomer [ Product name: Styrene monomer, manufactured by Wako Pure Chemical Industries, Ltd.] An epoxy resin composition 1L having 50 parts by weight was placed in a 2 L sample bottle with a lid. Three polypropylene cloth filters [trade name: filter with string, AS ONE Co., Ltd.] having a predetermined amount of aluminum nitride shown in Table 1 in the upper part, and three product names made by Mitsui Chemical Co., Ltd.] The filter was equally divided and stored, and the filter top was closed and immersed.

  Table 1 shows the composition, initial viscosity, and pot life of the epoxy resin compositions stored by the methods of Examples 1 to 6 and Comparative Examples 1 to 4. Note that the pot life of the epoxy resin composition is that the storage viscosity is measured from the result of storing the storage container in a constant temperature bath at 60 ° C., sampling the resin composition periodically, and measuring the viscosity at 25 ° C. The number of days required to double the initial viscosity was determined as the pot life.

  From the result of Table 1, when the epoxy resin composition containing an acid anhydride as a curing agent is stored in a system in which boron nitride coexists, the pot life is remarkably increased as compared with Comparative Examples 1 to 4, It can be seen that the method for storing the epoxy resin composition of the invention is a method having extremely excellent storage stability.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is the schematic which shows the storage method by Embodiment 1 of this invention. It is the schematic which shows the storage method by Embodiment 2 of this invention. 2 is a chemical formula showing a dihydroxyl structure in which an epoxy group of an epoxy resin is opened.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Container, 2 Epoxy resin composition, 3 Support body which accommodated boron nitride, 4 Support rod.

Claims (4)

  A storage method for storing an epoxy resin composition containing an epoxy resin and a curing agent in a container, wherein the container includes a support provided with boron nitride.   The storage method according to claim 1, wherein the curing agent is an acid anhydride curing agent.   The storage method according to claim 1 or 2, wherein the plurality of supports are immersed in an epoxy resin composition in a container.   A container for storage of an epoxy resin composition containing an epoxy resin and a curing agent, the container having a support provided with boron nitride.

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