JP2006066237A - Insulating polymeric material composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize electric physical properties and mechanical physical-properties equivalent to or better than a conventional polymer product using a bisphenol A type epoxy resin without worsening working efficiency, and to contributes to global environment conservation. <P>SOLUTION: Lignin extracted from plant biomass is epoxidized , and a hardening agent etc. is properly added to the epoxidized lignin and heated for three dimensional crosslinking to obtain the insulating polymeric material composition. The lignin is extracted from plant biomass, for example, by steaming and blasting, and the epoxidized lignin is obtained by glycidyl-etherification reaction of the extracted lignin and epichlorohydrin under a high alkalization atmosphere. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an insulating polymer material composition, and is used, for example, in an insulating configuration of a high-voltage device including a switchgear such as a circuit breaker or a disconnector in a housing.

  For example, it is applied to insulation configurations (for example, parts that require insulation) of voltage equipment (high voltage equipment, etc.) equipped with switchgear such as circuit breakers and disconnectors in the housing (for example, directly exposed to the outdoors) A composition obtained by curing a polymer material mainly composed of petroleum-derived thermosetting resin (resin using petroleum as a starting material; epoxy resin, etc.), for example, a polymer material is cast. A product (mold cast product; hereinafter referred to as a polymer product) composed of the composition has been widely known.

  Along with the sophistication and concentration of society, there is a strong demand for high-voltage devices, etc. that have large capacities, miniaturization, and high reliability (for example, mechanical properties and electrical properties). On the other hand, improvement of various characteristics has been demanded.

Generally, as a main component of a polymer material, for example, a glass transition point (hereinafter referred to as Tg) 100 ° C. or higher heat-resistant epoxy resin or a bisphenol A type epoxy resin having relatively high mechanical properties (strength etc.) In consideration of the case where the above-mentioned polymer product is disposed (for example, due to the reason of life or failure), a high polymer material having biodegradability is known. Development of molecular products has been attempted (for example, Patent Document 1).
JP 2002-358829 A.

In various technical fields, attempts have been made to apply a composition obtained by curing a plant-derived polymer material (for example, to a printed wiring board) (for example, Patent Document 2), for example, in a room temperature atmosphere. In this case, it is known that sufficient mechanical properties can be obtained. However, the composition uses an aldehyde as a curing agent, and the mechanical properties are lowered in a high temperature atmosphere. It was not applied to.
Japanese Patent Laid-Open No. 2002-53699.

  As described above, a polymer product using a heat-resistant epoxy resin having a glass transition point (hereinafter referred to as Tg) of 100 ° C. or higher as a main component of the polymer material is hard and fragile, and has a severe temperature change. If used underneath, there is a risk of cracking. For this reason, for example, a solid epoxy resin (for example, a result of a crack resistance test using a metal conductor of −30 ° C. or lower) is used as the main component of the polymer material, or a large amount of filler is added to the polymer material. Attempts have been made to improve the crack resistance and the like by adding it, but the viscosity of the polymer material becomes extremely high. For example, the pot life (minimum required for industrial work) Time), and workability may be deteriorated.

  The bisphenol A type epoxy resin is widely used as an industrial product because of its high mechanical properties. However, the bisphenol A itself is considered to be harmful as an environmental hormone, It is beginning to be a concern from the point of view of sex. If it is in a cured composition such as a polymer product, there is a report that bisphenol A hardly leaks out from the composition, and there is a report that it is not harmful. Even if it exists in the composition as described above, if unreacted bisphenol A (low molecular weight component) is present in the composition, the bisphenol A is present. May be leaked into the air and there are concerns.

  For example, in a polymer product manufacturing facility, in a limited environment such as a step of synthesizing a bisphenol A type epoxy resin and various additives, a step of casting a polymer material after the synthesis step, etc. There is a risk of a high concentration bisphenol A atmosphere. Even if each process of the production equipment is completely unmanned (the production line for polymer products is unmanned), ventilation equipment (equipment for purifying air in the use environment) is required in each process. For this reason (that is, a ventilation facility that was not assumed in the past is required), the product cost may increase.

  In the case of disposing of the above-mentioned polymer product (for example, disposing for reasons such as lifetime or failure), various treatment methods can be applied, but each has the following problems.

  In the case of polymer products made of polymer materials mainly composed of petroleum-derived substances (for example, epoxy resins, etc.), applying the method of incineration will emit a large amount of various harmful substances and carbon dioxide, resulting in environmental pollution, There was concern about the possibility of causing problems such as global warming. On the other hand, a method of simply landfilling the polymer product can be applied, but the final disposal sites related to the landfill process tend to decrease year by year. The remaining years of this final disposal site are estimated around 2008 by the former Ministry of Health. In addition, the former Economic Planning Agency predicts that the cost of waste disposal will rise around 2008, and the economic growth rate will be pushed down, based on the previous calculations by the former Ministry of Health and Welfare.

  In addition, there is an attempt to collect and reuse (recycle) the polymer product, but the reuse method has not been established and is hardly performed. Exceptionally, only members with relatively uniform quality (PE cable covering members used in polymer products) are recovered and used as thermal energy. However, since this thermal energy requires a combustion treatment step, Like this, there is a risk of causing problems such as environmental pollution and global warming.

  On the other hand, in the case of a polymer product made of a biodegradable polymer material, there is a risk of melting when used in an atmosphere at a temperature of 100 ° C. or higher. In the case of polymer products composed of biologically derived cross-linked compositions, aldehydes are used as cured products, and therefore have high mechanical properties under a normal temperature atmosphere (for example, a temperature environment in a printed wiring board). In a high temperature atmosphere (for example, an environment where a high voltage device or the like is used), sufficient mechanical properties may not be obtained.

  As described above, there is a demand for improving the various problems associated with the disposal of the polymer product while maintaining good properties (mechanical properties, electrical properties, etc.) of the polymer product.

  The present invention has been made based on the above problems, and can impart sufficient characteristics (mechanical properties, electrical properties) in polymer products such as high voltage devices without deteriorating workability, An object of the present invention is to provide an insulating polymer material composition having excellent environmental properties.

  The present invention is for solving the above-mentioned problems, and the invention according to claim 1 is made of a polymer material and is used for an insulation configuration of a voltage device, The lignin extracted from plant biomass is used as a main component, and the polymer material is heated and three-dimensionally crosslinked.

  The invention described in claim 2 is characterized in that, in the invention described in claim 1, lignin is epoxidized (for example, in an alkaline atmosphere).

  The invention described in claim 3 is characterized in that, in the invention described in claim 1 or 2, a curing agent is added to the polymer material.

  As in the present invention, by using lignin extracted from plant biomass as the main component of the polymer material, the lignin has an aromatic ring and an aliphatic side chain like the bisphenol A type epoxy resin. Sufficient electrical properties (insulating properties, etc.) and mechanical properties (tensile strength, etc.) can be obtained without using a large amount of filler as in conventional polymer products (at least using bisphenol A type epoxy resin) Electrical properties and mechanical properties similar to those of polymer material compositions can be obtained).

  The above-described polymer material composition does not generate harmful substances or carbon dioxide even when incinerated, and is biodegraded when landfilled in soil.

  As described above, according to the present invention, electrical properties and mechanical properties equivalent to or higher than those of conventional polymer products using bisphenol A type epoxy resin are obtained without deteriorating workability (for example, ensuring sufficient pot life). As well as contributing to the conservation of the global environment.

  Hereinafter, the insulating polymer material composition in the embodiment of the present invention will be described in detail.

  In this embodiment, for example, in an insulating polymer material composition applied to a portion of a polymer product that requires insulation, instead of using a petroleum-derived polymer material such as an epoxy resin, a naturally-derived polymer material In this case, a polymer material having a molecular structure close to that of bisphenol A is used.

  That is, if the polymer material is as described above, sufficiently good electrical and mechanical properties can be obtained and applied to a high voltage device, and the polymer material itself is carbon neutral. It has been found that even if the composition (polymer product or the like) formed is incinerated, emission of harmful substances and carbon dioxide can be prevented or suppressed. For example, it can be biodegraded when buried in soil. In such a composition composed of a naturally derived polymer material, an example applied to a printed wiring board is known, but there was no example applied to a high voltage device.

  As described above, lignin, which is a naturally occurring polymer material and has a molecular structure similar to bisphenol A, is one of the main components of plant biomass (living body). This lignin exists as a three-dimensional crosslinked body having phenylpropane as a structural unit in plant biomass. That is, lignin has a structure similar to bisphenol A having an aromatic ring and an aliphatic side chain in the structural unit, and derivatized (epoxidized) of lignin approximated to bisphenol A type epoxy resin. It can be read that it has physical properties.

  The lignin is generally known among plant biomass, particularly those contained in woody biomass, and is being studied for effective use. However, other plant biomass such as annual grasses is used. It is also included in a certain kenaf. In particular, about the core part of the kenaf, about 1/4 of the whole core part is occupied by lignin.

  Extraction methods of lignin in the above plant biomass include chemical pulp production process method (method of elution in an aqueous solution of sodium hydroxide and sodium sulfide), wood saccharification method (method using inorganic acid and oxygen), solvent Method (elution with an organic solvent (for example, a low-boiling point solvent such as alcohol, a high-boiling point solvent such as phenol, formic acid, DMSO, or a solvent (quinone or sulfuric acid) added to the above solvent)), Steam explosion method (for example, a method of elution in subcritical water at about 200 ° C. and several to several tens of atmospheres) and the like. According to each of these extraction methods, lignin in plant biomass is cracked and derivatized.

  In addition, the average molecular weight and structural formula of derivatized lignin as described above vary depending on the type of plant biomass as a raw material, the extraction method, extraction conditions, etc., and the reaction activity of the derivatized lignin is also determined. Although they may differ, they have properties similar to those of bisphenol A type epoxy resins, and can be applied to polymer products as substitute materials for the bisphenol A type epoxy resins.

  As described above, the activity of the reaction active part of lignin extracted from plant biomass may be reduced or deactivated by reaction with additives used in the extraction process. In such a case, it is possible to achieve the desired epoxidation with respect to the lignin by separately derivatizing the reaction active part or introducing a substituent.

  The epoxidation can be achieved by methods such as epoxide synthesis with hydrogen peroxide (epoxide synthesis for unsaturated bonds in lignin), photo-oxygen oxidation, glycidyl etherification (glycidyl etherification with epihalohydrin), etc. it can. In the case of lignin extracted by the steam explosion method, the lignin can be epoxidized more efficiently by subjecting the lignin and epichlorohydrin to a glycidyl etherification reaction in a highly alkaline atmosphere.

  An insulating polymer material composition can be obtained by thermosetting (for example, three-dimensional crosslinking) the epoxidized lignin (hereinafter referred to as epoxidized lignin). If necessary, various curing agents and curing accelerators may be used.

Various curing agents and curing accelerators can be applied as long as the epoxidized lignin can be thermally cured (three-dimensional crosslinking, etc.). Specific examples thereof include polyamines (for example, diethylenetriamine, Isophoronediamine, diaminodiaminodiphenylmethane, dicyandiamide, polyamide, epoxide modification, ketimine, etc.), acid anhydrides (eg, dodecenyl succinic anhydride, methyl nadic acid anhydride, trimellitic anhydride, pyrophosphoric anhydride, etc.), novolac type phenol resins, Phenol polymer, polysulfide, carboxylic acid-containing polyester resin, tertiary amine (eg, benzylmethyl, etc.), imidazole (eg, 2-methylimidazole, etc.), Lewis acid (BF ₃ monoethylamine, BF ₃ piperazine, etc.), aromatic sulfonium salt , Yoshi Examples include aromatic diazonium salts, resol type phenol resins, methylol group-containing urea resins, and methylol group-containing melamine resins.

[Example]
Next, examples of the insulating polymer material composition in the present embodiment will be described. First, in this example, lignin was extracted from plant biomass by steam explosion method, and the extracted lignin and epichlorohydrin were synthesized by glycidyl etherification reaction in a highly alkaline atmosphere to obtain an epoxidized lignin. It was.

  Thereafter, to the epoxidized lignin, various curing agents were added in predetermined amounts (stoichiometric amounts) as shown in Tables 1 and 2 below, respectively, under the respective conditions (curing temperature and curing time). Samples S1 to S42 of the insulating polymer material composition were prepared by heating and curing (three-dimensional crosslinking), respectively.

  In addition, as comparative examples with the samples S1 to S42, various curing agents shown in Tables 3 and 4 below (Tables) are used for bisphenol A type epoxy resins (bisphenol A type epoxy resins having an epoxy equivalent of about 190). 1, by adding a predetermined amount (stoichiometric amount) of the same curing agent as in Table 2, and heating and curing (three-dimensional crosslinking) under each condition (curing temperature, curing time) Samples P1 to P42 of the insulating polymer material composition were prepared.

  In each of the samples S1 to S42 and P1 to P42, the volume resistivity is measured as the electrical physical property (insulating property), and the mechanical physical property (support structure physical property when applied to a polymer product, with respect to the embedded metal) Measures tensile strength and tensile elongation as heat stress resistance), and measures rate of change of tensile strength value (hereinafter referred to as strength value after lapse) after being buried in soil as biodegradability. The results are shown in Table 5, Table 6, Table 7 and Table 8.

  In addition, the change rate of the intensity value after progress shown in the following Tables 5 to 8 is the first type test piece (thickness of 0.5 mm) based on JIS-K7113 for each of the samples S1 to S42 and P1 to P42. Test specimens), buried in the soil and left in a laboratory container (30 ° C, 80% RH atmosphere) for 6 months, and then measured the strength value after each passage. It is the change rate (ratio of change when the initial value is 100%) obtained by comparing with the value (tensile strength value before being buried in the soil).

  In the results shown in Tables 5 to 8, the samples S1 to S42 using the epoxidized lignin have a sufficiently high volume resistivity similarly to the samples P1 to P42 using the bisphenol A type epoxy resin, and the samples P1 to P42. (Comparing between samples using the same curing agent; for example, sample S1 and sample P1), it was confirmed that the tensile strength and tensile elongation were also high. Moreover, it was confirmed that the strength values of the samples S1 to S42 greatly decreased after the lapse of time as compared with the samples P1 to P42.

  The reason why the samples S1 to S42 have good tensile strength and tensile elongation as described above is that lignin constitutes an aliphatic chain and an aromatic ring, and the stress at the time of curing in the epoxidized lignin is the curing in the bisphenol A type epoxy resin. This is thought to be because it is easier to relax than the stress of time. In addition, the reason why the strength after the passage of samples S1 to S42 is lower than that of samples P1 to P42 is that lignin itself is a plant-derived material and is more susceptible to soil microorganisms and enzymes than samples P1 to P42. (It is likely to be biodegraded).

  Therefore, it can be read that by forming a polymer product with the polymer material composition such as samples S1 to S42, good electrical and mechanical properties can be imparted to the polymer product. Moreover, when processing the polymer product, even if it is incinerated, a large amount of harmful substances and carbon dioxide are generated like conventional polymer products (for example, products using bisphenol A type epoxy resin). However, it can be seen that when landfilled, biodegradation occurs over time.

  Although the present invention has been described in detail only for the specific examples described above, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical idea of the present invention. Such variations and modifications are naturally within the scope of the claims.

  For example, in the present invention, lignin (epoxidized lignin) is applied to a polymer material composition, and the effect of the lignin is not limited to the type of curing agent and the curing conditions. Further, the curing agent applicable to the present invention is not limited to the one used in the present embodiment. For example, two or more types of curing agents are used in consideration of improvement of work environment and shortening of work time. A mixture, an adduct of the curing agent, salts (for example, dimethylaminomethylphenol), and the like can be used, and a curing accelerator may be used in addition to the curing agent.

  Further, in the curing agent in this example, the stoichiometric amount of the curing agent was used for the purpose of comparing the samples S1 to S42 and the samples P1 to P42, but the addition amount of the curing agent varied depending on necessity. However, the present invention is not limited to the values shown in this embodiment. In general, it is known that the electrical and mechanical properties of the polymer material composition can be improved by adjusting the addition amount of the curing agent to about 80% to 90% of the stoichiometric amount. It has been.

  Furthermore, for example, the above-mentioned curing agent may be used by putting it in a microcapsule or by allowing it to be adsorbed on a molecular sieve or the like, thereby causing it to function potentially.

Claims (3)

It is made of a polymer material and is used for the insulation structure of voltage devices,
An insulating polymer material composition comprising lignin extracted from plant biomass as a main component of the polymer material, and the polymer material is heated and three-dimensionally crosslinked.   2. The insulating polymer material composition according to claim 1, wherein the lignin is epoxidized.   The insulating polymer material composition according to claim 1, wherein a curing agent is added to the polymer material.