JP2011225653A - Insulating polymer material composition and production method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat resistance of an insulating polymer material composition formed of a renewable source as a raw material.SOLUTION: A liquid epoxy resin composition which is the compatibilized product of a vegetable oil-derived epoxy resin and a plant-derived polyphenol, is obtained by mixing a vegetable oil-derived epoxy resin with a plant-derived polyphenol and heating the obtained mixture. A carbodiimide compound is added to the liquid epoxy resin composition and mixed, to which an additive such as a curing accelerator is added further, and heated to obtain the insulating polymer material composition. The carbodiimide compound contains at least two carbodiimide bonds in the molecule and includes a single polymer or a copolymer comprising at least one kind of repeating unit expressed by formula of -R-N=C=N-. In the formula, R represents an organic diisocyanate residue.

Description

  The present invention relates to an insulating polymer material composition, and more particularly to an insulating polymer material composition that is suitable for insulation of a power system having a high voltage and a high temperature. The present invention relates to an insulating polymer material composition that substitutes for a thermosetting resin such as unsaturated polyester or epoxy resin in a conventional insulating material, and a method for producing the insulating polymer material composition.

  As an insulating material and a structural material for high-voltage devices, a polymer composite cured product using a thermosetting resin such as an epoxy resin derived from petroleum starting from petroleum as a matrix, a so-called mold casting product is widely used. In addition, with the recent sophistication and concentration of society, there is a strong demand for large capacity, small size, and high reliability of equipment, and mold casting products are becoming increasingly important.

  However, the thermosetting resin used in these mold casting products uses petroleum-derived raw materials, and due to global problems such as the exhaustion of petroleum resources, it is possible to use renewable resources in the future. It has been demanded. Then, the technique regarding using a plant-derived raw material as an epoxy resin and its hardening | curing agent is proposed (patent documents 1-4).

  For example, Patent Document 1 proposes a technique related to an insulating composition made of a vegetable oil-derived epoxy resin. Patent Document 2 proposes a technique of using plant-derived phenol (lignin) as a curing agent for epoxy resin.

JP 2007-35337 A JP 2008-138061 A JP 2002-358829 A JP 2002-53699 A JP 2007-238652 A JP 2000-34392 A JP 2009-99332 A

  However, in the technology described in Patent Document 1, since a petroleum-derived phenol resin is used as a curing agent for epoxidized linseed oil, the plant degree is low, and a non-petroleum raw material that is a substitute for an existing thermosetting resin is used. It was hard to say that the insulation cured product was the starting material.

  Further, in the technique described in Patent Document 2, lignin used as a curing agent has a low phenolic hydroxyl group concentration that functions as a curing agent for epoxy resin, so that the density of the cross-linking points of the resulting cured product is reduced, resulting in petroleum origin. Mechanical strength and heat resistance higher than those of thermosetting resins made of the above raw materials could not be obtained.

  Furthermore, gallic acid derivatives have poor compatibility with epoxidized linseed oil, making it difficult to mix and disperse curing accelerators, fillers, silane coupling agents, etc., resulting in non-uniform cured products and physical properties of the cured products. There was a risk of variation.

  Therefore, the raw material of the epoxy resin that can satisfy the characteristics required as an industrial material is derived from petroleum.

  Therefore, the insulating polymer material composition of the present invention that solves the above problems is obtained by adding a carbodiimide compound to a liquid epoxy resin composition comprising one or more epoxidized vegetable oils and one or more plant-derived polyphenol derivatives. It is characterized by being three-dimensionally crosslinked.

  In the insulating polymer material composition, the plant-derived polyphenol derivative may be a gallic acid derivative.

  The insulating polymer material composition is a mixture of the epoxidized vegetable oil and the plant-derived polyphenol derivative, and the resulting mixture is heated to make the epoxidized vegetable oil and the plant-derived polyphenol compatible. It is characterized by that.

  Further, in the insulating polymer material composition, the gallic acid derivative is pyrogallol, methyl gallate, ethyl gallate, propyl gallate, isopropyl gallate, pentyl gallate, isopentyl gallate, hexadecyl gallate, gallic acid The aspect containing any one or more of heptadecyl and octadecyl gallate is mentioned.

  In the insulating polymer material composition, the epoxidized vegetable oil may be epoxidized linseed oil.

  Moreover, the insulating polymer material composition manufacturing method of the present invention that solves the above-described problems is obtained by a mixing step of mixing one or more types of epoxidized vegetable oil and one or more types of plant-derived polyphenol derivatives, and the mixing step. The mixture is heated to make the epoxidized vegetable oil and the plant-derived polyphenol derivative compatible, and the liquid epoxy resin composition obtained in the compatibility step is added with a carbodiimide compound to form a three-dimensional cross-link. And a curing step.

  According to the above invention, it can contribute to the heat resistance improvement of the insulating polymer material composition which consists of a raw material derived from non-petroleum.

The figure which shows the influence which the addition amount of carbodilite exerts on Tg and a maximum bending stress.

  The present invention relates to an insulating polymer material composition obtained by adding a carbodiimide compound to a liquid epoxy resin using a plant-derived raw material together with an epoxy resin and a curing agent, and the insulating polymer material composition It is related with the manufacturing method.

  An epoxy resin raw material that can satisfy the characteristics required as an industrial material is derived from petroleum. On the other hand, if it crosslinks three-dimensionally, it is an alternative to an epoxy resin raw material even if it is a natural raw material, and an insulating material composition made of a natural raw material is carbon neutral even if it is incinerated. It is not considered an outbreak.

  Therefore, attention was focused on vegetable oil-derived epoxy resins as epoxy resins starting from natural raw materials. The vegetable oil-derived epoxy resin is not particularly limited as long as it can be epoxidized, and examples thereof include epoxidized linseed oil and epoxidized soybean oil.

  For example, epoxidized linseed oil, like epoxidized soybean oil, is widely used as a stabilizer for polyvinyl chloride. However, since it has poor reactivity compared with general industrial epoxy resins, it takes time to cure, and since Tg (glass transition point) is low and mechanical strength is low, it has not been examined as an insulating / structural material.

  As a result of examining Tg improvement of epoxidized linseed oil this time, it was found that the cured product of epoxidized linseed oil is superior in insulation and has higher mechanical properties at high temperatures than industrial epoxy. It was found that the above physical properties can be obtained. Therefore, in the present invention, epoxidized linseed oil is positioned not as an auxiliary material such as a plasticizer but as an alternative to the epoxy resin material itself.

  And as a hardening | curing agent which reacts with the said epoxidized vegetable oil, this also paid attention to the natural raw material. Chemical substances that react with epoxy resins include amines, acid anhydrides, phenols, and imidazoles, all of which start with petroleum raw materials.

  Therefore, plant-derived polyphenols were studied as starting materials using natural raw materials. Plant-derived polyphenols are generic names for plant components that have multiple phenolic hydroxyl groups (hydroxyl groups bonded to aromatic rings such as benzene and naphthalene rings) in the molecule, and are synthesized when plants perform photosynthesis. It is. Specific examples include gallic acid, tannin, flavonol, isoflavone, catechin, quercetin, anthocyanin and the like. In addition, various chemical products and grades are made using these as raw materials.

  In the present invention, attention is focused on gallic acid derivatives as an example of plant-derived polyphenols. Examples of gallic acid derivatives include methyl gallate, ethyl gallate, butyl gallate, pentyl gallate, propyl gallate, isopropyl gallate, isopentyl gallate, octyl gallate, decyl gallate, dodecyl gallate, tridecyl gallate, Examples include tetradecyl gallate, pentadecyl gallate, hexadecyl gallate, heptadecyl gallate, octadecyl gallate, and pyrogallol. Among these gallic acid derivatives, propyl gallate, isopropyl gallate or pyrogallol having a low molecular weight and a low melting point are preferable. These were converted to phenol resins and used as a curing agent for the epoxidized vegetable oil. Phenol resination is polymerization of at least one of the above plant-derived polyphenols, and examples of the polymer obtained by phenol resin include bispyrogallol and pyrogallol acetone resin. In addition, you may use plant origin polyphenol, without making it phenol resin.

  The compounding ratio of the vegetable oil-derived epoxy resin and the plant-derived polyphenols is not particularly limited, and the addition amount may be determined in view of the physical properties of the finally obtained cured product. For example, the plant-derived polyphenols may be 10 to 50 parts by weight, preferably 25 to 40 parts by weight with respect to 100 parts by weight of the vegetable oil-derived epoxy resin. Moreover, it does not specifically limit about the addition amount of a hardening accelerator or a filler, It is preferable to determine addition amount in view of the physical property of the hardened | cured material finally obtained.

  As the curing accelerator, imidazole, tertiary amine, aromatic amine and the like can be used. Silica or alumina can be used as the filler, but a silane coupling agent may be added to adjust the interface between the filler and the resin.

  Even when plant-derived polyphenols are used as a curing agent, Tg depends on the epoxy group concentration of epoxidized linseed oil. Therefore, in order to raise Tg of hardened | cured material, it is necessary to increase the crosslinking point in hardened | cured material. Therefore, in the present invention, a carbodiimide compound is added to crosslink the cured products, thereby improving the cross-linking point density and improving the mechanical strength and glass transition temperature of the cured product.

  When reacting an epoxy resin with phenols, the compounding amount of the epoxy resin and phenols is determined from the epoxy equivalent and hydroxyl equivalent, but the epoxy group in the epoxidized linseed oil is in the molecular chain, and the reactivity is poor, so it is the optimal compounding The amount is not necessarily determined stoichiometrically. Therefore, phenols will be added excessively, and unreacted phenolic hydroxyl groups will remain in the cured product. Therefore, by bonding the remaining phenolic hydroxyl groups through a carbodiimide compound, the cross-linking points in the cured product are increased, and the mechanical strength and heat resistance are improved. The addition amount of the carbodiimide compound is not particularly limited, and the addition amount may be determined in view of the physical properties of the finally obtained cured product. For example, the carbodiimide compound may be 0.2 to 10 parts by weight, preferably 6 to 9 parts by weight with respect to 100 parts by weight of the vegetable oil-derived epoxy resin.

  The carbodiimide compound used in the present invention has two or more carbodiimide bonds in the molecule, and is represented by the formula —RN—C═N— (wherein R represents an organic diisocyanate residue). Homopolymers or copolymers comprising at least one repeating unit are included. The carbodiimide compound has an effect of inhibiting hydrolysis by a supplemental reaction with active hydrogen (carboxylic acid generated by hydrolysis, active hydrogen of hydroxyl group). Although the physical properties and reaction rate of the hydrolysis inhibitor itself vary depending on the type of R, the essential functions (such as supplementary reaction with active hydrogen) are substantially the same.

  The carbodiimide compound used in the present invention can be produced, for example, by a condensation reaction involving decarbonization of organic diisocyanate.

  Organic diisocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, a mixture of 2,4- and 2,6-tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 1-methoxyphenyl-2 , 4-diisocyanate, 4,4′-biphenylene diisocyanate, 3,3′-dimethoxy-4,4′-biphenyl diisocyanate, 3,3′-dimethyl-4,4′-biphenyl diisocyanate, 3,3′-dimethyldiphenylmethane -4,4'-diisocyanate, xylylene diisocyanate, hexamethylene-1,6-diisocyanate, lysine diisocyanate, hydrogenated methylene diphenyl diisocyanate, isophorone diisocyanate, tetramethylxylylene diisocyanate, And a mixture of these. In the present invention, an aromatic organic diisocyanate residue is suitable as the organic diisocyanate residue R in the above formula. Moreover, although the polymerization degree of the said carbodiimide compound is the range of 5-10,000, even if it uses 1 type or more of monoisocyanate simultaneously, it can be used controlling to a suitable polymerization degree. Monoisocyanates for sealing the ends of carbodiimide compounds and controlling the degree of polymerization in this way include phenyl isocyanate, (ortho, meta, para) -tolyl isocyanate, dimethylphenyl isocyanate, cyclohexyl isocyanate, butyl isocyanate, and chlorophenyl. Examples include isocyanate and naphthyl isocyanate.

  In general, carbodiimide compounds containing a carbodiimide group (—N═C═N—) are used as a crosslinking agent for oily resins containing active hydrogen, as a modifier for polyester resins, polylactic acid, and aqueous resins. (Patent Documents 5 to 7).

  In the method for producing an insulating polymer material composition according to an embodiment of the present invention, the vegetable oil-derived epoxy resin and the plant-derived polyphenol are mixed (mixing step), and then preheated at a predetermined temperature and the vegetable oil-derived epoxy resin and the A step of obtaining a liquid compatible material (liquid epoxy resin composition) in which a part of the plant-derived polyphenol forms a cross-linked structure (liquid epoxy resin composition), a carbodiimide compound added to the liquid compatible material, and heating It consists of the process (hardening process) which bridge | crosslinks the said vegetable oil origin epoxy resin and the said plant origin polyphenol by processing.

  Specifically, the vegetable oil-derived epoxy resin (liquid) as the main agent and the plant-derived polyphenol (solid) as the curing agent are mixed at room temperature (mixing step). In the mixing step, the mixing temperature of the vegetable oil-derived epoxy resin and the plant-derived polyphenol is not particularly limited, but may be room temperature.

  Next, the obtained mixture is preheated and compatible (compatibility process). The term "compatible" as used in the present invention means that the mixture of the main agent and the curing agent has a clear appearance. When compatible, a liquid compatible material (that is, a liquid epoxy resin composition) in which a part of the vegetable oil-derived epoxy resin and the plant-derived polyphenol forms a crosslinked structure is obtained. The range of crosslinking of the liquid epoxy resin composition is 1 to 80%, preferably 1 to 50%, more preferably 1 to 20%. The range of crosslinking of the liquid epoxy resin composition can be controlled by the heating temperature and the heating time of the liquid epoxy resin composition.

  And if this liquid epoxy resin composition does not have a solid hardening | curing agent, a liquid epoxy resin composition will be cooled below to preheating temperature, and reaction rate will be reduced.

  A carbodiimide compound is added to the liquid epoxy resin composition in a state where the reaction rate is low. And a hardening accelerator and a filler are added and it heat-processes, a vegetable oil origin epoxy resin and plant origin polyphenol are completely bridge | crosslinked, and insulation hardened | cured material (insulating polymer material composition) is obtained.

  In the compatibility step, preheating is preferably performed at a temperature higher than the melting point of the plant-derived polyphenol, and it is necessary to adjust the compatibility time depending on the temperature condition. Further, the mixing time can be shortened by stirring. However, if the compatibility time is too long, the liquid epoxy resin will be cured, so that it is possible to determine the optimal compatibility conditions (preheating time, preheating temperature) for each type of curing agent added to the liquid epoxy resin. preferable.

  Hereinafter, the insulating polymer material composition according to the present invention and the production method thereof will be described with reference to Example 1. The insulating polymer material composition and the production method thereof according to the present invention are not limited to the following Example 1, and the reaction conditions and the mixing ratio are appropriately changed within a range not impairing the effects of the invention. Good.

Example 1
As a vegetable oil-derived epoxy resin, epoxidized linseed oil (Adeka Co., Ltd., epoxidized linseed oil (product name: Adeka Sizer O-180A)), which is an epoxidized vegetable oil, was used. And as a hardening | curing agent of this epoxidized linseed oil, pyrogallol (made by Fuji Chemical Industry Co., Ltd.) which is 1 type of a gallic acid derivative was used.

  As the carbodiimide compound, carbodiimide V-05 manufactured by Nisshinbo Chemical was used. There are various grades of carbodiimide compounds, but they may be appropriately selected and used.

  As a curing accelerator, 2-ethyl-4-methyl-imidazole (Shikoku Kasei Kogyo Co., Ltd., product name Curesol 2E4MZ) was used. The same effect can be obtained even when a tertiary amine (Meiden Chemical Co., Ltd. L-86) or an aromatic amine (Meiden Chemical Co., Ltd. K-61B) is used as the curing agent. It was. The blending ratio is shown below. In addition, a weight part shows the weight percentage (wt%) with respect to a main ingredient.

(Combination)
Main agent: Epoxidized linseed oil 100 parts by weight Curing agent: Pyrogallol 35 parts by weight Curing accelerator: 2E4MZ 3 parts by weight Carbodiimide compound: Carbodilite V-05 0, 3, 5, 7, 10 parts by weight Epoxidized linseed oil and pyrogallol After mixing by blending, pre-heating in an oil bath at 150 ° C. gave a liquid epoxy resin in which epoxidized linseed oil and pyrogallol were compatible. Next, after adding Carbodilite V-05 and stirring and mixing, 2-ethyl-4-methyl-imidazole was added. The temperature for stirring and mixing Carbodilite V-05 is preferably 70 ° C to 130 ° C. The obtained resin composition was poured into a mold and cured at a predetermined temperature through a defoaming step. The addition amount of Carbodilite V-05 was changed from 0 to 10 parts by weight, and a cured product was prepared with each addition amount.

  Next, the physical properties of the cured product obtained by adding Carbodilite V-05 to a compatible product of epoxidized linseed oil and pyrogallol were evaluated. The evaluation method of the cured product was performed using Tg as an index of heat resistance and maximum bending stress as an index of mechanical enemy strength. Tg was determined from the inflection point of the linear expansion coefficient by the TMA method by cutting the cured product obtained by the heat treatment into a 4 mmφ × 15 mm cylindrical shape. For the maximum bending stress, a test piece was prepared in the obtained cured product, and the maximum bending stress was measured.

  FIG. 1 and Table 1 show the effect of the added amount of carbodilite on Tg and maximum bending stress. Addition of carbodilite dramatically improved Tg. Also, the mechanical strength (maximum bending stress) increased slightly. Moreover, although the unreacted phenolic hydroxyl group in the resin causes moisture absorption of the resin, there was an effect of reducing the moisture absorption rate and the boiling moisture absorption rate by reacting with the carbodilite.

  The insulating polymer material composition of the present invention improves heat resistance (Tg) by cross-linking residual hydroxyl groups that have not reacted with epoxy groups among the phenolic hydroxyl groups of pyrogallol as a curing agent with carbodiimide groups. And mechanical strength (maximum bending stress) can be improved. Further, if unreacted hydroxyl groups remain in the resin, there is a concern that the hygroscopic properties and the insulating properties may be deteriorated, but these properties are improved by the addition of a carbodiimide compound.

  As described above with reference to Example 1, according to the method for producing an insulating polymer material composition of the present invention, Tg is normal temperature using a vegetable oil-derived epoxy resin and a plant-derived polyphenol derivative, which are non-petroleum raw materials, as raw materials. Thus, a cured product (insulating polymer material composition) excellent in insulating performance can be obtained. And by adding a carbodiimide compound to a compatible product of a vegetable oil-derived epoxy resin and a plant-derived polyphenol derivative and curing it, heat resistance, mechanical strength, An insulating polymer material composition with improved properties can be obtained.

  The insulating polymer material composition of the present invention is a carbon neutral insulating polymer material composition because the raw material is a non-petroleum raw material. The insulating polymer material composition according to the present invention can be applied to insulating materials for electric power equipment. For example, it can be used for epoxy mold products such as insulating spacers, supporting insulators, insulating frames, insulating sheets, solid insulating switchgear (mini-cladding), molding equipment used in gas insulating equipment, and molding resins such as transformers.

Claims (6)

A liquid epoxy resin composition comprising one or more epoxidized vegetable oils and one or more plant-derived polyphenol derivatives,
An insulating polymer material composition obtained by adding a carbodiimide compound and three-dimensionally crosslinking. The insulating polymer material composition according to claim 1, wherein the plant-derived polyphenol derivative is a gallic acid derivative. The liquid epoxy resin composition is obtained by mixing the epoxidized vegetable oil and the plant-derived polyphenol derivative, heating the resulting mixture, and making the epoxidized vegetable oil and the plant-derived polyphenol compatible. The insulating polymer material composition according to claim 1 or 2. The gallic acid derivative is one or more of pyrogallol, methyl gallate, ethyl gallate, propyl gallate, isopropyl gallate, pentyl gallate, isopentyl gallate, hexadecyl gallate, heptadecyl gallate, and octadecyl gallate. The insulating polymer material composition according to claim 2, which is contained. The insulating polymer material composition according to any one of claims 1 to 4, wherein the epoxidized vegetable oil is an epoxidized linseed oil. A mixing step of mixing one or more epoxidized vegetable oils and one or more plant-derived polyphenol derivatives;
A compatibility step of heating the mixture obtained in the mixing step to make the epoxidized vegetable oil and the plant-derived polyphenol derivative compatible;
A method for producing an insulating polymer material composition, comprising: a curing step of adding a carbodiimide compound to the liquid epoxy resin composition obtained in the compatibility step and three-dimensionally crosslinking the composition.

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