JPH05117498A - Reactive plasticizer and epoxy resin composition containing the same - Google Patents

Abstract

PURPOSE:To obtain the title composition in which an epoxy resin curing agent can uniformly be dispersed without the aid of a solvent and which gives a flexible cured resin product, by compounding a reactive plasticizer comprising as a main component a glycidyl ester of an epoxidized chain dimer acid with an epoxy resin. CONSTITUTION:The title plasticizer comprises a glycidyl ester of an epoxide of a dimer acid component containing at least one member selected from among chain dimer acids and esters thereof represented by the formula in an amount of 50wt.% or more. In the formula, R<1> and R<2> are each hydrogen or lower alkyl, which may be identical or different; and m, n, p and q are each an integer of 0 or greater with the proviso that m+n=13 and p+q=15. The above dimer acid component may be mixed with a monocarboxylic fatty acid or ester thereof of the formula R<3>COOR<4> (wherein R<3> is a saturated or unsaturated 5-21C hydrocarbon group and R<4> is hydrogen or lower alkyl).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel reactive plasticizer and an epoxy resin composition containing the same. More specifically, the present invention includes a reactive plasticizer capable of giving an epoxy resin composition having an extremely low viscosity without using a solvent such as xylene or alcohol, and the reactive plasticizer and the epoxy resin, and even without a solvent. The present invention relates to an epoxy resin composition in which an epoxy resin curing agent can be uniformly dispersed and which gives a resin cured product having flexibility.

[0002]

BACKGROUND OF THE INVENTION Dimer acid is a polyvalent carboxylic acid obtained by polymerization reaction of two or more molecules of unsaturated fatty acid, and is usually obtained as a mixture of two or more kinds, and various applications as a mixture. Have been offered to. This dimer acid is the highest molecular weight dibasic acid which is highly reactive and hydrophobic and which can be obtained industrially, and the polymer derived from it is amorphous and flexible and has good stability at low temperature. It is used in many fields because it shows sex. For example, a non-reactive dimer acid polyamide obtained from dimer acid as a raw material is tough, shows flexibility, and has good adhesive performance, and thus is used as a component of an adhesive, an ink, a surface coating agent, Reactive substances are compounded with epoxy resins as epoxy resin curing agents, and are used for surface coating of metals, plastics, ceramics, etc., or as two-component reactive adhesives.

Such dimer acid has hitherto been used with a montmorillonite clay as a catalyst to produce unsaturated fatty acid 2
It is produced by a method of dimerizing at a high temperature of about 00 to 250 ° C. In this method, since the trans-double bond is generally conjugated to increase the thermal polymerization rate, tall oil fatty acid or soybean oil fatty acid having a high linoleic acid content is used as a raw material, and its industrial process is standardized. Has been done.

By the way, when dimer acid is produced by such a method, the linoleic acid contained in the raw material is dimerized and

[Chemical 4] In addition to the chain dimer acid represented by

[Chemical 5] as well as

[Chemical 6] A mixture containing the cyclic dimer acid represented by is obtained.

However, when the content of the cyclic dimer acid is high, the viscosity and the pour point become high. Therefore, for example, the glycidyl ester compound obtained by epoxidizing the above dimer acid mixture at the double bond and then reacting it with epichlorohydrin is melted. It has a high viscosity, and when it is used as a reactive plasticizer of an epoxy resin, it needs to be used in a large amount, and the resulting epoxy resin is inferior in impact resistance and high temperature stability.

By the way, it is generally known that in hydrocarbons having the same carbon chain length, a compound having a cyclic structure in the molecule has a higher melting point and higher viscosity than a chain structure compound due to its steric characteristics. There is. When unsaturated fatty acid containing 78% by weight of oleic acid was used as a raw material and condensed in the presence of a montmorillonite catalyst at a temperature of about 250 ° C., the amount of cyclic structure was reduced to 40% by weight of linear dimer acid. Although it has been reported that a dimer acid composition containing the same can be obtained [[Journal of American Oil Chemistry Society (J. Am. Oil
Chemist's Soc. ) "Volume 51, 52
2 (1974)], no method for increasing the chain dimer acid content to 50% by weight or more has been known so far.

[0007]

Under these circumstances, the present invention has a lower viscosity and better low-temperature fluidity than conventional ones, and does not require the use of a solvent such as xylene or alcohol. An inexpensive reactive plasticizer that can give an epoxy resin composition with an extremely low viscosity that can be used in a solvent, has excellent compatibility with the epoxy resin, and is introduced by reacting with the epoxy resin during curing to impart flexibility. And an epoxy resin composition containing this reactive plasticizer, in which an epoxy resin curing agent can be homogeneously dispersed even in a solventless system, and which provides a resin cured product having flexibility. It is a thing.

[0008]

Means for Solving the Problems The inventors of the present invention previously contained 50% by weight or more of a chain dimer acid or its ester or both by dimerizing a specific raw material under specific conditions. We succeeded in obtaining a dimer acid composition having low viscosity and good low-temperature fluidity (Japanese Patent Application No. 2-184).
294), and as a result of further research, after epoxidizing this dimer acid composition or a mixture thereof with a specific monovalent fatty acid or its ester at the double bond site with peracid or the like, glycidyl ester with epichlorohydrin It was found that the object can be achieved by using the modified compound as a reactive plasticizer, and the present invention has been completed based on this finding.

That is, the present invention has the general formula

[Chemical 7] (In the formula, R ¹ and R ² are each a hydrogen atom or a lower alkyl group, and they may be the same or different, and m, n, p and q are each an integer of 0 or 1 or more. , M + n = 13, p + q = 15), and a glycidyl esterified product of an epoxidized dimer acid component containing at least 50% by weight of at least one selected from the chain dimer acid represented by Acid component and general formula

[Chemical 8] (Wherein R ³ is a saturated or unsaturated hydrocarbon group having 5 to 21 carbon atoms, and R ⁴ is a hydrogen atom or a lower alkyl group) and at least 1 selected from the group consisting of esters and esters thereof. A reactive plasticizer comprising a glycidyl ester of an epoxidized product of a mixture with a seed, and an epoxy resin composition containing the reactive plasticizer.

The dimer acid component used in the present invention contains at least one selected from the chain dimer acid represented by the above general formula (I), its monoester and diester in a proportion of 50% by weight or more. It is necessary to. If this amount is less than 50% by weight, the object of the present invention cannot be sufficiently achieved. In addition, trimer acid or its ester may be produced as a by-product during the production of this dimer acid, and such a dimer acid may be used as it is.

The dimer acid component has 1 carbon atom.
And unsaturated dimers of 8 unsaturated fatty acids such as oleic acid, linoleic acid and its lower alkyl esters such as methyl ester, ethyl ester, n-propyl ester, isopropyl ester, n-butyl ester and tert-butyl ester. it can. These may be a single component or a mixed component containing two or more kinds.

The dimer acid component is obtained by polymerizing the unsaturated fatty acid or ester thereof in the presence of a high acid strength Lewis acid type or Bronsted acid type catalyst, and further hydrolyzing the ester when used as a raw material. Particularly preferred is a raw material obtained using an unsaturated fatty acid containing 70% by weight or more of oleic acid or a lower alkyl ester thereof or a lower alkyl ester thereof as a raw material.

The dimer acid component thus obtained usually contains monomer components such as unreacted components and by-produced branched fatty acids, so these are removed by distillation under reduced pressure, and then the distillation residue is separated into molecules. It may be purified by distillation and used, or may be used in a state in which the monomer component is contained.

The reactive plasticizer of the present invention can be obtained by epoxidizing the dimer acid component thus obtained and then subjecting it to glycidyl esterification with epichlorohydrin. In this case, the dimer acid is optionally added. The component may be mixed with the monovalent fatty acid represented by the general formula (II) or its ester.

Examples of the monovalent fatty acid and its ester include caproic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, myristoleic acid,
Palmitoleic acid, oleic acid, elaidic acid, linoleic acid and their methyl esters, ethyl esters, n-
Examples include propyl ester, isopropyl ester, n-butyl ester, isobutyl ester, tert-butyl ester. These may be used alone or in combination of two or more.

The reactive plasticizer of the present invention is prepared by reacting a dimer acid component or a mixture of the dimer acid component and the monovalent fatty acid or its ester with an epoxidizing agent to epoxidize the double bond, and then to form a catalyst. In the presence of epichlorohydrin,
It is usually added in an amount of 3 to 20 mol, preferably 5 to 10 mol, relative to 1 mol of the free or esterified carboxyl group, and usually 80 to 150 ° C., preferably 9
It can be produced by reacting at a temperature in the range of 0 to 120 ° C. for 0.2 to 10 hours, preferably 0.5 to 3 hours.

Examples of the epoxidizing agent include peracids such as peracetic acid and formic acid, hydrogen peroxide, and the like. In the epoxidation reaction, the epoxidizing agent is added to the dimer acid component.
1 to 1.5 equivalents are used in terms of equivalents of the double bond, 5 to 5
Stirring is carried out at 0 ° C., preferably 10 to 30 ° C. for 1 to 10 hours, preferably 3 to 5 hours.

As the catalyst, for example, a tertiary amine or a quaternary ammonium salt is used. Examples of the tertiary amine include triethylamine and tri-n-
Propylamine, benzyldimethylamine, triethanolamine, and the like. Examples of the quaternary ammonium salt include tetramethylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, and benzyltrimethylammonium acetate. , Methyltriethylammonium chloride and the like.

These catalysts may be used alone or in combination of two or more, and the amount thereof used is usually 0.1% with respect to the total amount of the acid component and epichlorohydrin.
02-1.0% by weight, preferably 0.1-0.6% by weight
It is selected in the range of.

The reaction product is treated with alkali hydroxide or the like and dehydrochlorinated, and then the desired glycidyl esterified product is isolated and purified by a conventional separation means such as filtration, solvent extraction, washing, distillation and recrystallization. To do.

The thus-obtained glycidyl esterified product has an extremely low viscosity as compared with conventional ones, and an epoxy resin composition using this as a reactive plasticizer has a low viscosity even without using a solvent. Therefore, the epoxy resin curing agent can be easily and uniformly dispersed.

The uncured epoxy resin used in the epoxy resin composition of the present invention is not particularly limited. For example, bisphenol A type epoxy resin, epoxy novolac resin, alicyclic epoxy resin, polyfunctional epoxy resin, brominated epoxy resin. A resin such as a resin having at least two epoxy groups in one molecule is used.

[0023]

The reactive plasticizer of the present invention contains glycidyl ester of epoxidized chain dimer acid as a main component, has low viscosity, good low temperature fluidity and low cost, and has excellent compatibility with epoxy resin, When blended with an epoxy resin, it is introduced by reacting with the epoxy resin at the time of curing, and has a remarkable effect that flexibility can be imparted.

Since the epoxy resin composition containing the reactive plasticizer of the present invention has a low viscosity, it is not necessary to use a solvent, the workability is good, and the human body is not adversely affected and the environment is not polluted. Even in the system, the epoxy resin curing agent can be uniformly dispersed, and a resin cured product having flexibility can be provided.

The epoxy resin composition of the present invention is suitably used for applications such as reinforced resin materials, electrical insulating materials, paints, adhesives, civil engineering and construction materials.

[0026]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 As a raw material, a chain dimer acid 5 represented by the general formula (I) was used.
Dimer acid composition containing 8% by weight (iodine value = 7
0.3) was added to this, 1.02 equivalent of acetic anhydride containing 7% peracetic acid was added to the double bond, and the mixture was stirred at 20 ° C. for 3 hours, and then epichlorohydrin was added to the carboxyl group 5 times. Molar and benzyltriethylammonium chloride were added in an amount of 0.5% by weight based on the total amount of the dimer acid composition and epichlorohydrin, and the reaction was carried out at 100 ° C. for 1 hour under a nitrogen atmosphere.

Then, a 50% by weight aqueous solution containing 1.1 times mol of sodium hydroxide was added to the carboxyl group,
After holding at 105 ° C. for 0.5 hour, the mixture was rapidly cooled, the precipitated sodium chloride was filtered off, and excess epichlorohydrin was azeotropically distilled with water, and then toluene was added to the mixture, followed by extraction with washing with water. The toluene layer was dehydrated with anhydrous sodium sulfate, and then toluene was completely removed by distillation under reduced pressure to produce a reactive plasticizer.

Next, 25 parts by weight of the reactive plasticizer was added to 75 parts by weight of an epoxy resin having an epoxy equivalent of 190 (Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.) and stirred to form a transparent low-viscosity epoxy resin composition. Prepared. When an epoxy resin curing agent was added to this composition and cured, a flexible cured product was obtained.

Examples 2 to 8 and Comparative Examples 1 to 3 Instead of the raw material of Example 1, a composition whose composition component is a methyl ester compound as shown in Table 1 was used as a raw material, and Example 7 was used.
In the same manner as in Example 1 except that the amount of epichlorohydrin was changed to 3-fold mol, and that in Examples 3 and 5, the amount of epichlorohydrin was changed to 3-fold mol and triethylamine was used instead of benzyltriethylammonium chloride. Each reactive plasticizer and each comparative product for comparison were prepared as each sample. Table 1 shows the results of measuring the viscosity of these samples at 25 ° C. using a B type viscometer.

Next, 80 parts by weight of an epoxy resin having an epoxy equivalent of 190 (Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.) was added with 20 parts by weight of each of the above reactive plasticizers or each of the comparison products, and the mixture was stirred. A composition was prepared. Table 1 also shows the results of measuring the viscosity of these compositions at 25 ° C. using a B type viscometer.

From the results shown in Table 1, it can be seen that the reactive plasticizers of the respective examples and the epoxy resin compositions containing the same each have a remarkably lower viscosity than the corresponding ones of the respective comparative examples. ..

Next, when an epoxy resin curing agent was added to the epoxy resin compositions of the respective examples and cured, a cured product having flexibility was obtained.

[Table 1]

Claims (4)

[Claims] 1. A general formula: (In the formula, R ¹ and R ² are each a hydrogen atom or a lower alkyl group, and they may be the same or different, and m, n, p and q are each an integer of 0 or 1 or more. , M + n = 13, p + q = 15), and a glycidyl esterification product of an epoxidation product of a dimer acid component containing at least 50% by weight of at least one selected from the chain dimer acid and its ester. Plasticizer. 2. (A) General formula: (In the formula, R ¹ and R ² are each a hydrogen atom or a lower alkyl group, and they may be the same or different, and m, n, p and q are each an integer of 0 or 1 or more. , M + n = 13, and p + q = 15), and a dimer acid component containing at least 50% by weight of at least one selected from the chain dimer acid and its ester, and (B) the general formula: ] (Wherein R ³ is a saturated or unsaturated hydrocarbon group having 5 to 21 carbon atoms, and R ⁴ is a hydrogen atom or a lower alkyl group) and at least 1 selected from the group consisting of esters and esters thereof. A reactive plasticizer comprising a glycidyl ester of an epoxide of a mixture with a seed. 3. An epoxy resin composition comprising the reactive plasticizer according to claim 1 and an epoxy resin. 4. An epoxy resin composition comprising the reactive plasticizer according to claim 2 and an epoxy resin.