JPS62267319A - Epoxy resin curing agent composition - Google Patents

Abstract

PURPOSE:The titled composition, containing an organic phosphine compound in a carboxylic acid anhydride, hardly changing the viscosity of the system with time and having improved storage stability without emitting CO2. CONSTITUTION:A composition obtained by containing an organic phosphine compound, preferably a triarylphosphine, e.g. triphenylphosphine, etc., in an amount of preferably 0.1-5wt% in a carboxylic acid anhydride, e.g. 3- methyltetrahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, methylnadic anhydride, dodecenylsuccinic anhydride, etc. The content of the maleic anhydride is preferably <=0.1wt%.

Description

Detailed Description of the Invention [Industrial Application Field 1] The present invention provides a carboxylic anhydride-based epoxy resin curing agent composition with excellent storage stability, which is characterized by containing a leading phosphine compound as a curing accelerator. Regarding.

[Conventional Q Technology] Polyamides, polyamines, carboxylic acid anhydrides, and the like are conventionally known as curing agents for epoxy control. Generally, the reaction rate between epoxy resins and carboxylic acid anhydrides is slow, and tertiary amines are currently widely used as curing accelerators.

Tertiary amine is usually added in an amount of about 0.2 to 7 parts per 100 parts by weight of epoxy resin and 50 to 130 parts by weight of carboxylic acid anhydride, but the amount of tertiary amine is about 3% or less of the total. Therefore, it is better to mix it with the acid anhydride in advance because the measuring and mixing time will be shortened and the work will be easier.

[Problems to be Solved by the Invention] However, there is no problem when used for a while after mixing, but when stored for a long time, the viscosity of the carboxylic acid anhydride increases and carbon dioxide gas is generated, causing the container to dry. Lack of storage stability has been a major problem, such as swelling and, in extreme cases, the container bursting.

For this reason, studies have been reported to extremely reduce the content of maleic anhydride, which is a component that is particularly likely to generate carbon dioxide gas (Japanese Patent Publication No. 54-20240, Japanese Patent Application Laid-Open No. 53-1982).
No. 52600).

However, the present inventors have found that even when a carboxylic acid anhydride containing no maleic anhydride (for example, an alicyclic acid anhydride produced by hydrogenation) is mixed with a three-pointed amine as a curing accelerator and stored for a long time, It is recognized that the viscosity increases over time and carbon dioxide gas is generated, and a carboxylic acid anhydride curing agent composition containing an amine curing accelerator is basically an unstable combination.

Therefore, there has been a strong demand for creating a composition that does not change over time when mixed with a curing accelerator.

[Means for Solving the Problems] The present inventors have solved these problems in a fundamental way, and have carried out various studies on compounds that improve storage stability and have sufficient performance as a curing accelerator. As a result, we discovered that by mixing a phosphine compound with a carboxylic acid anhydride instead of a amine, the desired objective could be achieved, and the properties of the cured product obtained by 1q were sufficient for practical use.Based on this knowledge, we The present invention was completed.

That is, an object of the present invention is to provide a standard epoxy resin curing agent composition with excellent storage stability, which is characterized by containing an organic phosphine compound in a carboxylic acid anhydride.

The carboxylic anhydride in the present invention includes 3-methyltetrahydrophthalic anhydride, 4-methyltetrahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, methylnadic anhydride, Solid at room temperature, such as dodecenyl succinic anhydride and their structural or geometric isomers, as well as hexahydrophthalic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, trimellitic lfi hydrate, and benzophenonetetracarboxylic anhydride. An example is one obtained by mixing and modifying with an acid anhydride to liquefy. Here, it is desirable for the residual amount of maleic anhydride, which is a type of raw material, to be reduced as much as possible, and in particular, it is preferably 0.1% by weight or less.

In addition, the organic phosphine compound is represented by the general formula [1] [wherein,
R, R and R3 represent a hydrogen atom, an alkyl group, an aryl group such as a phenyl group, a tolyl group, a cycloalkyl group such as a cyclohexyl group, and may be the same or different.

In addition, the following formula (wherein R represents an alkane, R' and RLL represent a hydrogen atom, an alkyl group, an aryl group such as a phenyl group or a tolyl group, or a cycloalkyl group such as a cyclohexyl group, and may be the same or different) It's okay.

10, and may be an organic group containing an organic phosphine, such as in the case where R' and RH are hydrogen atoms. However, this excludes the case where R1, R2 and R3 are all hydrogen atoms. ]. Specifically, tertiary phosphine compounds such as triphenylphosphine, tributylphosphine, tricyclohexylphosphine, and methyldiphenylphosphine, secondary phosphine compounds such as butylphenylphosphine and diphenylphosphine, and primary phosphine compounds such as phenylphosphine and octylphosphine. , and tertiary bisphosphine compounds such as bis(diphenylphosphino)methane and 1,2-bis(diphenylphosphino)ethane, and 1 selected from the group consisting of these.
A species or two or more species may be used. Among these, it is preferable to use arylphosphine compounds, and triarylphosphines such as triphenylphosphine are particularly preferable.

The organic phosphine compound is preferably mixed in an amount of 0.01 to 10% by weight relative to the carboxylic anhydride,
Particularly preferably, it is 0.1-5% by weight. If the amount is less than this range, it is difficult to obtain the desired effect, and even if it is more than this, there is no significant difference in effectiveness, which is economically disadvantageous.

The mixing of organic bosphine compounds into carboxylic acid anhydrides is
Heating in the range from air temperature to the boiling point of the carboxylic acid anhydride, preferably at 25 to 120'C, for 10 minutes to 2 hours according to a conventional method. This can be easily done by mixing without stirring or under heating.

The epoxy resins to which the curing agent according to the present invention can be applied include:
Not limited in particular, known ones, such as glycidyl ether type epoxy resins such as bisphenol △ type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin, glycidyl Nisdel type epoxy resin, glycidylamine type epoxy resin. , cycloaliphatic epoxy resins, heterocyclic epoxy resins, halogenated epoxy resins, and other epoxy resins.

Various additives such as fillers, pigments, diluents, and flexibility-imparting agents can be added to the epoxy resin curing agent composition according to the present invention, if necessary.

[Example] Below, the present invention will be described in detail with reference to Examples and Comparative Examples.

Example 1 Methylhexahydrophthalanhydride (Me-Hl-IPA
) 100 parts by weight and 5 parts by weight of triphenylphosphine were mixed at 40°C for 30 minutes, then cooled for 25 minutes.
It was stored at °C, and the viscosity and amount of gas generated after one month were measured. The results obtained are shown in the table.

The viscosity was measured using a B-type viscometer at a temperature of 25°C, and the amount of carbon dioxide gas generated was determined according to JIS K-2301.
Measured according to.

Examples 2 to 6 Compositions were prepared in the same manner as in Example 1 by changing the types and amounts of carboxylic acid anhydrides and organic bosphines, and the viscosity and amount of carbon dioxide gas generated were measured.

The results are shown in the table.

Comparative Example 1 100 parts by weight of methylhexahydrophthalic anhydride core and Uca
t-3A102 fl, 8-diaza-bicyclo(5,4
,○〉Undecene-7.2 ethylhexyl core salt: 2 parts by weight of SunApro (packaged in (3)) were mixed at air temperature for 10 minutes, and the same test as in Example 1 was conducted.

The results obtained are shown in the table.

Comparative Example 2 100 parts of methylhexahydrophthalic anhydride and 3 parts of 2-ethyl-4-methylimidazole were mixed at 40°C.
After mixing for 0 minutes, the same test as in Example 1 was conducted. The results obtained are shown in the table.

Comparative Example 3 A trial was prepared by replacing 2.2 parts by weight of Ucat-3A10 in Comparative Example 1 with 3 parts by weight of lauryldimethylamine.
A test similar to Example 1 was conducted.

The results obtained are shown in the table.

Ratio 13≧1 I14 Methyltetrahydrophthalanhydride mm100ff1 part and 2
3 parts by weight of ethyl-4-methylimidazole at air temperature
After mixing for 0 minutes, the same test as in Example 1 was conducted. The results are shown in the table.

[Effect of the invention 1] The epoxy resin curing agent composition according to the present invention shows less change in system viscosity over time than conventional compositions using Sankumi amine as a curing accelerator, and does not generate carbon dioxide scum. The composition is remarkably shelf-stable.

Procedural amendment (voluntary) August 29, 1985 Commissioner of the Patent Office Kuro 1) Aki Yu j2 1, Indication of the case 1986 Patent application No. 1”11
No. 187 Juha 2, Title of the invention: Epoxy resin curing agent composition 3, Relationship with the case of the person making the amendment: Patent applicant 4, ? Number of inventions increased by +I positive None 5
, Date of amendment order Vol. 6, Subject of amendment Jun 7 of the "Detailed Description of the Invention" in the specification, Contents of the amendment (1) Replacement of "alkane" in line 7 from the bottom of No. 5 of the specification with "alkylene". correct.

(2) "It is preferable to mix with the carboxylic acid anhydride in an amount of 0.01 to 10% by weight, particularly preferably 0.1 to 5% by weight," in lines 4 to 1 from the bottom of page 6 of the specification. It is.”
0.01 to 5% by weight of carboxylic anhydride
It is preferable to mix in an amount of 10 parts by weight, particularly preferably 0.1 to 5 parts by weight. ” he corrected.

Claims (3)

[Claims] (1) An epoxy resin curing agent composition comprising a carboxylic acid anhydride and an organic phosphine compound. (2) The epoxy resin curing agent composition according to claim (1), wherein the organic phosphine compound is an arylphosphine compound. (3) The epoxy resin curing agent composition according to claim (1), wherein the content of maleic anhydride in the carboxylic anhydride is 0.1% by weight or less.