JP2005054027A - Polyoxazolidone resin, method for producing the same and use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polyoxazolidone resin having excellent insulation properties, heat resistance, adhesiveness and flexibility, to provide a method for efficiently producing the resin and to obtain an insulating coating to become a coating film comprising the resin, having insulation properties, heat resistance, adhesiveness, flexibility and soldering properties. <P>SOLUTION: The polyoxazolidone resin is represented by general formula (A) (R<SP>1</SP>is an organic compound group consisting of 2-20 carbon atoms, hydrogen and oxygen; R<SP>2</SP>is a hydrocarbon residue consisting of 2-20 carbon atoms and hydrogen; R<SP>3</SP>is hydrogen or a 1-6C hydrocarbon residue; B is a 1-12C hydrocarbon residue; n is an integer of 1-300). The insulating coating is obtained by using the resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a novel polyoxazolidone resin, a method for producing the same, an insulating paint, and an insulated wire.

  In recent years, along with the miniaturization and weight reduction of electronic circuits, the diameter of wires and cables has been reduced, the weight has been reduced, and the substrate has been made thinner and lighter. It is desired.

  A resin having an oxazolidone ring obtained by a reaction between an inexpensive polyfunctional isocyanate and a polyfunctional epoxy compound (see Non-Patent Document 2) is a novel electrical insulating and heat resistant resin material because it exhibits excellent thermal characteristics. Expected. This type of resin obtained by the reaction of a polyfunctional isocyanate and a polyfunctional epoxy resin is complicated and difficult to proceed with the formation reaction, and a large amount of undesirable by-products are formed. The main by-product is an isocyanurate formed by the trimerization of isocyanate and a polyether produced by homopolymerization of epoxides.

Polyoxazolidone resin containing a structure other than such an oxazolidone ring is generally good in heat resistance but hard and brittle, that is, the resin after thermosetting has high hardness. When processing such as bending, there is a disadvantage that the coating is torn, and in particular, a drawback is pointed out that the impact strength is small or the flexibility is poor.
Furthermore, in the reaction between isocyanate and epoxide, it has been pointed out that when the amount of epoxide increases, a strong exothermic reaction occurs, resulting in scorching of the molded body and thermal deterioration of the molded body.

On the other hand, a method of forming a polyoxazolidone resin containing no trimerized isocyanurate from bisurethane and bisepoxide is known (see Non-Patent Document 1). With such a method, heat resistance and electrical insulation are known. If sufficient flexibility can be imparted to the polyoxazolidone exhibiting properties, it is expected that it can be used as an inexpensive heat-resistant insulating coating material.
Iwakura et al., Journal of Polymer Science Part A-1 (J. Polymer Sci. Part A-1) vol. 4, pp. 751-760, 1966 Sander et al, Journal of Applied Polymer Science (Vol. 9, 1994, 1965), Journal of Applied Polymer Science (J. Appl. Polymer Sci.).

The polyoxazolidone described in Non-Patent Document 1 does not contain a trimerized isocyanurate group and is a structurally simple polymer having only an oxazoline ring as a basic skeleton. There is a problem that it is not thermally stable such as cross-linking by reaction, is inferior in heat resistance, and has insufficient adhesiveness. Further, the method described in Non-Patent Document 1 has a problem that the reaction rate is not sufficient, and it takes time to obtain a useful polymer having a high molecular weight.
The objective of this invention is providing the polyoxazolidone resin which solved the said subject, and its efficient manufacturing method.

  In order to achieve the above object, the present inventors have continually studied and found that a dialkyl carbamate compound (a) obtained by blocking a diisocyanate with a blocking agent and a diepoxy compound (b) are reacted with diisocyanate in the presence of a catalyst. To efficiently produce a novel polyoxazolidone resin having no isocyanurate group and no epoxy group capable of solving the above-mentioned problems by reacting the alkyl carbamate compound (a) with the diepoxy compound (b) in excess. In addition, when the novel resin is applied and baked on a conductor, it becomes a coating film having heat resistance, adhesiveness, flexibility and solderability, and is found to be useful as an insulating paint. The present invention has been completed.

（式中、Ｒ¹は炭素数２〜２０の炭素、水素、酸素から構成される有機化合物基、Ｒ²は炭素数２〜２０の炭素、水素から構成される炭化水素残基、Ｒ³は水素又は炭素数１〜６の炭化水素残基、Ｂは炭素数１〜１２の炭化水素残基、ｎは１〜３００の整数を表す）で表されるポリオキサゾリドン樹脂であり、また、ジイソシアネートのアルキルカーバメート化合物（ａ）とジエポキシ化合物（ｂ）とを触媒の存在下、ジイソシアネートのアルキルカーバメート化合物（ａ）を過剰に用いて反応させることを特徴とするポリオキサゾリドン樹脂の製造方法であり、また、上記ポリオキサゾリドン樹脂を含有する絶縁塗料であり、さらに該絶縁塗料を塗布、焼き付けてなる絶縁層を有する絶縁電線である。 That is, the present invention provides the following general formula (A)

(Wherein R ¹ is an organic compound group composed of carbon, hydrogen and oxygen having 2 to 20 carbon atoms, R ² is a hydrocarbon residue composed of carbon and carbon having 2 to 20 carbon atoms, R ³ is A polyoxazolidone resin represented by hydrogen or a hydrocarbon residue having 1 to 6 carbon atoms, B is a hydrocarbon residue having 1 to 12 carbon atoms, and n is an integer of 1 to 300. A method for producing a polyoxazolidone resin, comprising reacting an alkyl carbamate compound (a) and a diepoxy compound (b) in the presence of a catalyst using an excess of an alkyl carbamate compound (a) of a diisocyanate, An insulating wire containing the polyoxazolidone resin, and further having an insulating layer formed by applying and baking the insulating coating.

  Since the resin of the present invention is a polyoxazolidone resin having no isocyanurate group and no epoxy group, it is excellent in insulation, heat resistance, adhesiveness and flexibility. In particular, when the resin is applied and baked on a conductor Furthermore, it becomes a coating film having insulating properties, heat resistance, adhesiveness, flexibility and solderability, and is useful as an insulating coating. In addition, the resin can be produced efficiently by carrying out the method of the present invention.

In the present invention, examples of the diisocyanate used to obtain an alkyl carbamate compound of diisocyanate include aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate.
Examples of aromatic diisocyanates include tolylene diisocyanate (tentatively referred to as TDI), 4,4′-diphenylmethane diisocyanate (tentatively referred to as MDI-PH), 1,5-naphthalene diisocyanate (referred to as NDI), and 3,3′-dimethyl. And diphenyl-4,4′-diisocyanate (tentatively referred to as TODI).

  Aliphatic or alicyclic diisocyanate is a compound having an isocyanato group bonded to methylene, methine and / or isopropylidene, for example, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (hereinafter referred to as HDI), 2,2,4 (or 2,4,4) -trimethyl-1,6-diisocyanatohexane, lysine diisocyanate, etc., having 4-18 carbon atoms (preferably 5-14, more preferably 6-12) Aliphatic diisocyanate, isophorone diisocyanate (hereinafter referred to as IPDI), 1,4-diisocyanatocyclohexane, 1,3-bis (isocyanatomethyl) -cyclohexane, 1,3-bis (2-isocyanatopropyl-2) Yl) -cyclohexane, 4, Carbon such as alicyclic diisocyanate, tetramethylxylylene diisocyanate, xylylene diisocyanate, etc. having 8 to 22, preferably 8 to 18, more preferably 8 to 16 carbon atoms such as' -dicyclohexylmethane diisocyanate, norbornane dimethyl diisocyanate, norbornane diisocyanate Examples are aliphatic diisocyanates having an aromatic ring of formula 8-22, preferably 8-18, more preferably 8-16.

  As a blocking agent for blocking the isocyanato group of diisocyanate to obtain an alkyl carbamate compound (a), a monoalcohol can be used, for example, methanol, ethanol, propanol, isopropyl alcohol, n-butanol, 2-ethylhexanol, butyl cellosolve, Examples thereof include polyethylene glycol monoethyl ether. Two or more of these monoalcohols may be used in combination. Preferred blocking agents are 2-ethylhexanol, butanol and isopropanol.

  The amount of the blocking agent is preferably equivalent to the isocyanate group of the aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate, but the unreacted alcohol can be recovered after using the equivalent or more. The blocking reaction temperature is usually 20 to 150 ° C.

  It is desirable to block the diisocyanate with a monoalcohol and then perform a condensation reaction with the diepoxy compound (b). However, condensation is performed while adding the diisocyanate to the mixture of the diepoxy compound (b) and the monoalcohol. You can also react.

  Specific examples of the diepoxy compound (b) used in the present invention include glycidyl ethers, glycidyl esters, linear aliphatic epoxides, alicyclic epoxides, and the like.

  Examples of glycidyl ethers include bisphenol A, bisphenol F, bisphenol AD, bisphenol S, tetramethyl bisphenol A, tetramethyl bisphenol F, tetramethyl bisphenol AD, tetramethyl bisphenol S, tetrabromobisphenol A, tetrachlorobisphenol A, Bisphenol type epoxy resin obtained by glycidylation of bisphenols such as tetrafluorobisphenol A, epoxy resin obtained by glycidylation of other dihydric phenols such as biphenol, dihydroxynaphthalene and 9,9-bis (4-hydroxyphenyl) fluorene,

  Examples of glycidyl esters include terephthalic acid diglycidyl ester, phthalic acid diglycidyl ester, hexahydrophthalic acid and dimer acid diglycidyl ester.

Examples of the linear aliphatic epoxides include epoxidized polybutadiene and epoxidized soybean oil. Examples of the alicyclic epoxide include Daicel Chemical Industries' Celoxide 2021, 3000, 3,4-epoxy-6-methylcyclohexyl carboxylate, 3,4-epoxycyclohexyl carboxylate, and the like.
Preferred are glycidyl ethers, more preferred are bisphenol type epoxy resins, and more preferred are glycidyl ethers of bisphenol A (tentatively referred to as BPA-DGE).

  In the present invention, it is important to react the diepoxy compound (b) with an excess of the diisocyanate alkyl carbamate compound (a). Preferably, the amount of the diisocyanate alkyl carbamate compound (a) used is 1.01 to 1.1 mole ratio with respect to 1 mole (2 equivalents) of the diepoxy compound (b). If it is less than that, the curing reaction of the diepoxy compound occurs, and there is a tendency that the molecular weight of the polyoxazolidone resin cannot be increased, and if it exceeds the above range, an allophanate compound is generated due to the remaining dialkyl carbamate compound. For this reason, the heat resistance of the target product may not be sufficient. More preferably, the molar ratio is 1.01-1.05. More preferably, it is 1.01-1.03 molar ratio.

The resin is produced by mixing these diepoxy compounds (b) with a diisocyanate dialkyl carbamate compound (a) in the presence of a catalyst and mixing the diisocyanate alkyl carbamate compound (a) in the molar ratio as described above. Thus, a polyoxazolidone resin having an alkyl carbamate at the target end can be obtained.
Alternatively, the condensation reaction can be carried out while the diepoxy compound (b) is kept at a predetermined temperature in advance and the alkyl carbamate compound of diisocyanate is added in the presence of a catalyst.

  The production of the polyoxazolidone resin can be performed without a solvent or in the presence of a solvent. When a solvent is used, N, N-dimethylformamide (DMF), N, N-diethylformamide, N-methyl-2-pyrrolidone (tentatively referred to as NMP), dimethyl sulfoxide (DMSO), dimethylacetamide (tentatively named DMAc) And a solvent containing no active hydrogen such as methyl isobutyl ketone and butyl cellosolve acetate is preferred.

The reaction temperature of the diepoxy compound (b) and the diisocyanate alkyl carbamate compound (a) when the polyepazolidone resin is produced by mixing the diepoxy compound (b) and the diisocyanate alkyl carbamate compound (a) is 100. It is preferable to be carried out at a temperature between 230C and 230C. More preferably, it is 120 to 220 ° C. More preferably, it is 150 degreeC-200 degreeC.
As the reaction proceeds, the blocking agent is regenerated from the alkyl carbamate compound, which can be removed from the system using a decanter or the like.
If the reaction temperature is too low, the activity of the catalyst is low, and side reactions such as formation of isocyanurate rings tend to occur. Even if the reaction temperature is too high, the side reaction proceeds.

  In the case where the diepoxy compound (b) is kept at a predetermined temperature in advance and the alkyl carbamate compound of diisocyanate is added in portions, it is desirable to add the catalyst to the diepoxy compound (b) side in advance. In this case, a predetermined amount of the raw material epoxy compound is charged into the reactor and then heated to adjust the temperature to a predetermined temperature. Thereafter, the catalyst is added as it is or mixed with an appropriate solvent. The charging temperature is 20 to 200 ° C., preferably 80 to 200 ° C., more preferably 120 to 190 ° C. Especially preferably, it is 140-180 degreeC. When the catalyst is introduced at a predetermined temperature or lower, the reaction between the epoxy group and the intramolecular secondary alcohol group is promoted until the predetermined reaction temperature is reached, and the concentration of the epoxy group may decrease. There is a risk that the reaction will run out of control if the catalyst is added at.

  Next, the alkyl carbamate compound of isocyanate is added as it is or mixed with a suitable solvent. Divide into one or several times and drop stepwise or continuously. The dropping time is usually preferably 30 minutes or longer. Further, it is preferably dropped over 1 to 10 hours, more preferably 2 to 5 hours. When the dropping time is shorter than the predetermined time, the amount of isocyanate ring generated increases, and when the dropping time is longer than the predetermined time, the epoxy compound tends to be altered.

The reaction temperature is usually in the range of 100 to 230 ° C, preferably 120 to 220 ° C, more preferably 150 to 200 ° C, still more preferably 150 to 190 ° C, and particularly preferably 160 to 180 ° C. It is good to carry out.
If the temperature is higher than a predetermined temperature, the resin may be deteriorated.If the temperature is lower than the predetermined temperature, the dissociation rate of the blocking agent is slow, the progress of the reaction is slow and the reaction is not sufficiently completed. A resin containing many undesirable isocyanurate rings will be produced, and the resulting resin will have poor properties such as flexibility and adhesion.

（式中、Ｒは同種または異種の炭素数１ないし１０の炭化水素基である）
で表されるホスフィンオキシド化合物は、一つの極限構造式である。燐原子と酸素原子の間を二重結合で表現しているが、酸素原子上に電子が偏ってアニオンとなり、燐原子上にカチオンが生じた（Ｐ⁺−Ｏ^-）形の極限構造式も取り得る。また、燐原子上のカチオンは共役系を通して全体に非局在化している。本発明の方法において、式（１）で表されるホスフィンオキシド化合物は、これらすべてを含んだ共鳴混成体として理解されるべきである。 Next, the catalyst will be described.
General formula (1) which becomes a catalyst in the method of the present invention

(Wherein R is the same or different hydrocarbon group having 1 to 10 carbon atoms)
The phosphine oxide compound represented by the formula is one ultimate structural formula. A double bond is expressed between the phosphorus atom and the oxygen atom, but the (P ⁺ -O ⁻ ) form of the ultimate structural formula in which electrons are biased on the oxygen atom to become anions and cations are generated on the phosphorus atoms I can take it. In addition, cations on the phosphorus atom are delocalized throughout the conjugated system. In the method of the present invention, the phosphine oxide compound represented by the formula (1) should be understood as a resonance hybrid containing all of these.

When the phosphine oxide compound represented by the formula (1) contains water, the interaction between the water and the phosphine oxide is not limited as long as the characteristics of the compound are not lost and the method of the present invention is not inhibited. I do not care. R in the phosphine oxide compound represented by the formula (1) is the same or different hydrocarbon group having 1 to 10 carbon atoms, specifically, for example, methyl, ethyl, n-propyl, isopropyl, allyl, n-butyl, sec-butyl, tert-butyl, 2-butenyl, 1-pentyl, 2-pentyl, 3-pentyl, 2-methyl-1-butyl, isopentyl, tert-pentyl, 3-methyl-2-butyl, Neopentyl, n-hexyl, 4-methyl-2-pentyl, cyclopentyl, cyclohexyl, 1-heptyl, 3-heptyl, 1-octyl, 2-octyl, 2-ethyl-1-hexyl, 1,1-dimethyl-3, 3-dimethylbutyl (common name, tert-octyl), nonyl, decyl, phenyl, 4-tolyl, benzyl, 1-phenylethyl It is selected from a hydrocarbon radical of aliphatic or aromatic, such as 2-phenylethyl. Of these, an aliphatic hydrocarbon group having 1 to 8 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, tert-butyl, tert-pentyl or 1,1-dimethyl-3,3-dimethylbutyl is preferable. A methyl group or an ethyl group is more preferable. Particularly preferably R is a methyl group.
A specific compound of formula (1) is tris [tris (dimethylamino) phosphoranylideneamino] phosphine oxide (cat. A).

  The phosphine oxide compound represented by the formula (1) is G.I. N. It can be synthesized by the method described in GN Koidan et al., Journal of General Chemistry of the USSR (USSR), 55, 1453, 1985. These phosphine oxide compounds may be used alone or in combination of two or more.

（式中、Ｒは同種または異種の炭素数１ないし１０の炭化水素基である）
で表されるホスファゼニウム化合物中のカチオンは、その電荷が中心の燐原子上に局在する極限構造式で代表しているが、これ以外に無数の極限構造式が描かれ、実際にはその正電荷は全体に非局在化している。
式（２）で表されるホスファゼニウム化合物中のＲは、式（１）で表されるホスフィンオキシド化合物のＲと同一である。また、式（２）で表されるホスファゼニウム化合物中のＺ^-は、ハロゲンアニオン、ヒドロキシアニオン、アルコキシアニオン、アリールオキシアニオンまたはカルボキシアニオンである。 Further, the general formula (2) which becomes a catalyst in the method of the present invention.

(Wherein R is the same or different hydrocarbon group having 1 to 10 carbon atoms)
The cation in the phosphazenium compound represented by is represented by an extreme structural formula in which the charge is localized on the central phosphorus atom. The charges are delocalized throughout.
R in the phosphazenium compound represented by the formula (2) is the same as R of the phosphine oxide compound represented by the formula (1). Z ⁻ in the phosphazenium compound represented by the formula (2) is a halogen anion, a hydroxy anion, an alkoxy anion, an aryloxy anion or a carboxy anion.

Specific examples of these Z ⁻ include halogen anions such as fluorine anion, chlorine anion, bromine anion and iodine anion, and hydroxy anions, and examples thereof include methanol, ethanol, n-propanol, isopropanol, allyl. Examples include alkoxy anions derived from alcohols such as alcohol, n-butanol, sec-butanol, tert-butanol, cyclohexanol, 2-heptanol, 1-octanol, 1-decanol, and octahydronaphthol. Furthermore, aryloxyanions derived from aromatic hydroxy compounds such as phenol, cresol, xylenol, naphthol, 2-methyl-1-naphthol or 9-phenanthrol, such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, Examples thereof include a carboxy anion derived from a carboxylic acid such as caproic acid, decane carboxylic acid or oleic acid.

More preferably among these, alkoxy derived from a hydroxy anion, for example, a saturated aliphatic alcohol having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol or tert-butanol. An anion, for example, an aryloxy anion derived from an aromatic hydroxy compound having 6 to 8 carbon atoms such as phenol or cresol. More preferred are a hydroxy anion, a methoxy anion or a phenoxy anion, and particularly preferred is a hydroxy anion. As a specific compound of the formula (2), tetrakis [tris (dimethylamino) phosphoranylideneamino] phosphonium (cat.B): [(Me ₂ N) ₃ P═N] ₄ P ⁺ · OH ⁻ is there.

  These phosphazenium compounds can be synthesized by the method described on pages 12 to 13 of EP0791600 or a similar method. These phosphazenium compounds may be used alone or in combination of two or more. Further, a phosphazenium compound represented by the formula (1) and a phosphazenium compound represented by the formula (2) may be mixed and used.

  The usage-amount of the catalyst represented by Formula (1) and Formula (2) is normally used in 5 ppm-2 weight% with respect to diepoxy compound (b). Preferably, it is 10 ppm to 1% by weight. The catalyst can also be used after diluting in a suitable solvent.

  A dissociation promoter that promotes dissociation of the blocking agent can be used together with the catalyst represented by the formula (1) and the formula (2). Examples of dissociation promoters include organometallic salts such as tin, zinc, and lead. The dissociation accelerator is usually used in the range of 10 ppm to 1% by weight with respect to the diepoxy compound (b).

  In addition to the catalysts represented by the formulas (1) and (2), a conventionally known catalyst can also be used. Commonly used catalysts include, for example, metal alcoholates such as butoxy lithium and sodium methoxy, for example, Lewis acids such as lithium chloride and aluminum chloride, and mixtures of Lewis acids and Lewis bases such as triphenylphosphine oxide, such as Tetramethylammonium, tetraethylammonium, tetrabutylammonium, trilaurylmethylammonium, benzyltributylammonium chloride, etc., quaternary ammonium salts such as bromide, iodide, acetate,

  For example, triethylamine, dibutylmethylamine, N, N-dimethylbenzylamine, N, N, N ′, N′-tetramethylethylenediamine, 1,5-diazabicyclo (4,3,0) nonene-5, 1,8- Diazabicyclo [5.4.0] undecene-7 (DBU), 6-dibutylamino-1,8-diazabicyclo [5.4.0] undecene-7, 1,4-diazabicyclo [2.2.2] octane, Tertiary amines such as N-methylmorpholine, 2-ethyl-4-methylimidazole (tentatively referred to as EMI), imidazoles such as 2-phenylimidazole, and the like.

  Two or more kinds of catalysts other than the catalysts represented by the above formulas (1) and (2) and the catalysts represented by the formulas (1) and (2) may be used in combination. In addition, the catalyst represented by Formula (1) and Formula (2) is preferable from the viewpoint of catalytic activity and the difficulty of generating a gel, and when two or more types are used together, Formula (1) and Formula It is preferable to mainly use the catalyst represented by (2).

  When adjusting an insulating coating using the polyoxazolidone resin of the present invention obtained as described above, other epoxy resins and / or other polyisocyanates and derivatives thereof can be used in combination.

For the insulating paint using the polyoxazolidone resin of the present invention, the following solvents, curing accelerators, pigments, fillers, additives, and the like that are commonly used in the art can be used. These are appropriately mixed to form an insulating paint.
Examples of the solvent include hydrocarbons such as benzene, toluene, xylene, cyclohexane, mineral spirit, naphtha, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, ethyl acetate, acetic acid-n-butyl, propylene glycol monomethyl ether acetate. And esters such as methanol, isopropanol, n-butanol, butyl cellosolve, butyl carbitol and the like, water and the like.

  Examples of the curing accelerator include imidazoles, tertiary amines, phosphines, aminotriazoles, organic metal salts such as tin, zinc and lead, and organic pigments such as quinacridone, azo and phthalocyanine. , Inorganic pigments such as titanium oxide, metal foil pigments, rust preventive pigments, fillers such as barium sulfate, calcium carbonate, silica, carbon black, talc, clay, etc., UV absorbers such as hindered amines, benzotriazoles, benzophenones , Hindered phenol-based, phosphorus-based, sulfur-based, hydrazide-based antioxidants, silane-based, titanium-based coupling agents, leveling agents, rheology control agents, pigment dispersants, anti-repellent agents, antifoaming agents, etc. These additives can be used. Moreover, reinforcing materials, such as glass fiber, glass cloth, and carbon fiber, can be contained as needed.

  Further, the insulating paint of the present invention is not limited to the characteristics of the present invention, but a thermoplastic resin such as polyamide, polyester, polysulfone, polyvinyl formal, and epoxy, polyester, polyesterimide, polyurethane, polyamideimide, melamine resin It is also possible to add thermosetting resins such as phenolic resins, dyes, lubricants, other paint additives, and the like.

  In order to produce an insulated wire using the insulating paint of the present invention, the above insulating paint is adjusted to a viscosity suitable for work with an appropriate solvent, and then applied and baked on a conductor such as an annealed copper wire according to a conventional method. Insulating layer.

  Furthermore, an insulating layer coated with other insulating paint and baked is generally provided on the upper layer of the insulating layer coated and baked with the insulating paint of the present invention, as is generally done to impart other characteristics. Is also possible. For example, when heat resistance is further required, a polyimide insulating coating or a polyamideimide coating is used.

  Further, when the polyoxazolidone resin of the present invention is used as an enameled wire varnish, a triazine compound, a heterocyclic mercaptan compound, or the like can be added for the purpose of improving the adhesion to an electric conductor. For example, syn-triazine-2,4,6-trithiol, monocyclohexylamine salt of syn-triazine-2,4,6-trithiol, syn-triazine-2,4-trithiol-6-cyclohexylaminosulfene, 2- Examples include amino-5-mercapto 1,3,4-thiadiazole. Among these, syn-triazine-2,4,6-trithiol and the like are preferable.

  The blending amount of the triazine compound is preferably in the range of 0.005 to 1% by weight with respect to the varnish resin content in the enameled wire varnish. If it is less than 0.005% by weight, it is insufficient to obtain an effect on adhesion, and if it exceeds 1% by weight, the film becomes hard and flexibility becomes difficult. More preferably, the content is 0.01 to 0.2% by weight as a good balance between adhesion and flexibility. The weight of the resin serving as a reference for the addition amount is based on the numerical value of the nonvolatile content test according to 7.3 of JIS C2351-1988.

  Examples of the metal used as an object to be coated as an electric conductor include copper, iron, nickel, stainless steel, aluminum, silver, and gold, and these metals may be used alone or in combination of two or more kinds. Further, the shape of these metals may be a thread shape, a plate shape, or a molded shape. Of these, copper wire is preferred because of its high versatility.

  In particular, when obtaining an enameled wire, there are no restrictions on the conditions for applying and baking the varnish for enameled wire on the linear electric conductor, and the usual application and baking conditions are employed. For example, by passing a linear electric conductor through a metal die set in an applicator, a varnish for enamel wire diluted to an appropriate concentration with a stock solution or a solvent is applied, and a baking furnace set at 300 to 500 ° C Cure through. This operation is continuously repeated several times, and then wound on an enameled wire winding frame to obtain a product. Examples of the baking furnace to be used include an electric furnace and a hot air circulating furnace. The baking speed, that is, the winding, is obtained in order to obtain an optimum degree of hardening depending on the size of the furnace, the set temperature, the number of coating and baking. Speed is selected.

  Embodiments of the present invention will be described below with reference to examples, but the present invention is not limited to the following examples. In the examples and comparative examples, “parts” or “%” are based on weight unless otherwise specified. Moreover, the physical property evaluation test method of resin which concerns on an Example and a comparative example was performed with the method described below.

<Solid content concentration>
About 1 g of varnish was developed in an aluminum cup with a diameter of 5 cm, weighed accurately, heated for 2 hours under nitrogen at 120 ° C., further heated to 210 ° C., dried for 2 hours, transferred to a desiccator, and weighed after reaching room temperature. Weigh accurately. Thereafter, the solid content concentration is calculated by the following equation.
Solid content concentration (% by weight) = (weight after drying / initial weight) × 100

<< 5% weight loss temperature >>
The sample after the measurement of the solid content concentration was measured for 5% weight loss temperature of the polymer in a nitrogen using a differential heat / thermogravimetric analyzer at a heating rate of 10 ° C./min.

<< Flexibility as wire covering material >>
After the varnish was attached to a copper wire having a diameter of 0.5 mm, wiped with felt, and the process of curing at 300 ° C. for 30 seconds was repeated three times, the diameters of 2.5, 2.0, 1.5, 1.0, 360 ° wrapping was performed on a 0.5 mm stainless steel rod (hereinafter referred to as 5d, 4d, 3d, 2d, and 1d, respectively), and the diameter of the copper wire coating wound around was observed. .

<< Evaluation of flexibility as metal sheet coating agent >>
A varnish was applied so that the solid content of the polyoxazolidone resin was 0.25 g on one side of a copper plate and an aluminum plate (hereinafter referred to as an aluminum plate) of 50 mm (length) × 50 mm (width) × 0.5 mm (thickness), After the solvent is evaporated in an oven at 120 ° C. for 1 hour, it is transferred to an oven at 230 ° C. and cured for 15 minutes. The cured product was taken out and cooled to room temperature, and the metal plate was folded in two so that the coated surface was on the outside, and it was observed how far the cured product would crack when folded. (Maximum bending angle is 180 °)

<< Evaluation of adhesion to copper foil >>
Polyimide film: Kapton 100H film 25 μm coated with a wire rod so that the varnish concentration is about 10 μm after drying, dried at 200 ° C. for 5 minutes, and then overlaid with a 1/2 ounce (18 μm) rolled copper foil black treated surface. A test piece is made by press bonding at 210 ° C. and 20 MPa for 5 minutes.
The 90-degree peel strength of this film was measured and used as a measure of adhesive strength.
In the normal state, 90 degree peel strength of 0.5 or more was designated as A, and 0.5 or less was designated as B.

<< Evaluation of dielectric breakdown of resin film >>
A uniform film having a thickness of 0.1 to 0.2 mm was prepared using the target resin, and the breakdown voltage per mm thickness of the film was measured. The measuring device used Withstand voltage tester (Model: TP-5115 ADMPS), measured 5 times, and calculated | required the average value.

<Measurement of number average molecular weight of resin>
The target resin was dissolved in DMF to obtain a sampling solution.
The number average molecular weight of the target product was determined by gel permeation chromatography (GPC) using a standard PPG calibration curve.

<Inspection of residual epoxy groups (during polymerization)>
A part of the solution was sampled during the polymerization, and sandwiched between rock salt plates, the reaction was continued using an infrared absorption spectrum measuring apparatus (IR) until no infrared absorption of epoxy groups was observed. The infrared absorption spectrum was measured with a Fourier transform infrared spectrophotometer (FT-IR360: manufactured by Nicole).

<Polymerization state>
The presence or absence of gelation during the synthesis of the polyoxolidone resin was visually observed, and the product that was able to be synthesized stably without any gel formation was A, the product that partially produced the gel was B, the entire system was gelled Those that could not be synthesized were denoted by C.

《Quantitative analysis of oxazolidone ring》
About the obtained polyoxazolidone resin, the stretching vibration peak (near 1750 cm ⁻¹⁾ of the carbonyl group derived from the oxazolidone ring contained in the polyoxazolidone resin of the infrared absorption spectrum obtained by measuring with an infrared absorption spectrum measuring device (IR). ) And an isocyanurate ring-derived carbonyl group stretching vibration peak (near 1709 cm ⁻¹ ), an absorbance ratio (IS / OX ratio) was determined.

  The content of isocyanurate is preferably not more than 0.1, particularly preferably not more than 0.03, in terms of IS / OX ratio, that is, the absorbance ratio. By being in this range, when it is set to a varnish state or a prepreg state, the storage stability of the resin composition of the present invention is further improved, and the flexibility of the resin is further improved.

In a 100 ml separable flask, 11.1 g (0.029 mol) of a bisphenol A type epoxy resin [epoxy equivalent = 172], 10.1 g (0.03 mol) of an IPA carbamate compound of MDI-PH (mp = 137 ° C.) ) And 10% cat. B catalyst-containing DMAc solution (2.0 g) and DMAc (42 g) as a solvent were charged, and the mixture was heated to 160 ° C. with stirring in a nitrogen stream, and the reaction was continued for 6 hours while distilling off the produced isopropanol.
After distillation of isopropanol was confirmed that the completely finished, the result of the product was analyzed by infrared absorption spectrum, disappeared absorption based on epoxy group is seen to 915 cm ^-1, oxazolidone ring is seen to 1752cm ^-1 Based on this, the expression of carbonyl group absorption was confirmed.
Absorption based on epoxy group is seen in the vicinity of 915 cm ^-1 is not observed at all, also absorption from isocyanurate observed near 1709 cm ^-1 was observed at all. (See Figure 1)
As an index of the heat resistance of this product in Example 1, a 5% weight loss temperature was measured by thermobalance analysis using the resin after solvent removal, and it showed 354 ° C. The results are shown in Tables 1 and 2.
The polyoxazolidone compound obtained in this example is obtained from infrared absorption spectrum analysis (FIG. 1), proton nuclear magnetic resonance spectrum analysis (FIG. 2), and carbon nuclear magnetic resonance spectrum analysis (FIG. 3). It can be confirmed that the structural formula is as shown in the general formula (A). That is, both end groups of the polyoxazolidone resin are alkyl carbamates, and IR analysis and H-NMR analysis (presence of 9.2 ppm of urethane group hydrogen signal) and C13-NMR analysis (urethane group carbonyl carbon signal 169. From the presence of 5 ppm). Furthermore, it can be confirmed from the GPC analysis of the product that the IPA carbamate compound of MDI-PH as a raw material is not present.
Therefore, it can confirm that it is what is shown by structural formula like General formula (A) from said comprehensive analysis result.

  The procedure was the same as in Example 1 except for the conditions shown in Table 1. The results are shown in Tables 1 and 2.

  The procedure was the same as in Example 1 except for the conditions shown in Table 1. The results are shown in Tables 1 and 2.

  The procedure was the same as in Example 1 except for the conditions shown in Table 1. The results are shown in Tables 1 and 2.

In a 100 ml flask, 11.7 g (0.029 mol) of “Epicoat YX4000H” (Biphenyl type epoxy resin manufactured by Japan Epoxy Resin; epoxy equivalent = 195), and 10.2 g (0.002 mol) of an isopropyl carbamate compound of MDI-PH. 03 mol) and 42 g of DMAc as a solvent and 10% cat. The catalyst solution was charged with 2.5 g of the catalyst B, heated to 165 ° C. to 170 ° C. with stirring under a nitrogen stream, and the reaction was continued for 5 hours while distilling off the produced isopropyl alcohol. After confirming that the distillation of IPA was completed, the products shown in Tables 1 and 2 were obtained.
In addition, the polyoxazolidone compound obtained in this example is composed of an infrared absorption spectrum analysis (FIG. 4), a proton nuclear magnetic resonance spectrum analysis (FIG. 5), and a carbon nuclear magnetic resonance spectrum analysis (FIG. 6). From the typical result, it can be confirmed that the structural formula is as shown in the general formula (A).

10.2 g of isopropyl carbamate compound of MDI-PH in Example 5, 10% cat. In place of 2.5 g of the catalyst solution B, 10% cat. 1 dissolved in 11.1 g (0.029 mol) of diisopropyl carbonate compound (mp = 200 ° C.) of TODI and DMAc was used. A catalyst solution (2.0 g) was charged, and the mixture was heated to 160 ° C. to 170 ° C. with stirring under a nitrogen stream, and the reaction was continued for 6 hours while distilling off the produced IPA.
After confirming that the distillation of IPA was completed, the products shown in Tables 1 and 2 were obtained.
(Comparative Example 1)

A separable flask containing 10 parts of bisphenol A type epoxy resin (oxide equivalent 185), 15 parts of NMP and 0.1 part of EMI catalyst is equipped with a stirrer, thermometer, cooling pipe, nitrogen blowing pipe, and nitrogen is introduced into the flask. While blowing, the mixture was heated to 130 ° C. with stirring, and a mixture of 7.6 parts of MDI-PH and 27 parts of NMP was added over 1 hour while maintaining the reaction temperature at 130 ° C. After completion of the addition, stirring was continued for 6 hours while maintaining the reaction temperature at 130 ° C. to obtain a polyoxazolidone resin.
In the infrared absorption spectrum of the obtained polyoxazolidone resin, a strong peak based on the stretching vibration of the carbonyl group derived from the oxazolidone ring structure is near 1752 cm ⁻¹ , and a peak based on the stretching vibration of the carbonyl group of isocyanurate is 1709 cm ^−. is ¹ observed, whereas the peak based on the stretching vibration of isocyanate group (2270 cm around ^-1) was observed. The results of IR analysis and the like of the obtained polyoxazolidone resin are shown in Table 1.
(Comparative Example 2)

A separable flask containing 20 parts of a bisphenol A type epoxy resin (oxide equivalent 185) was equipped with a stirrer, thermometer, cooling tube and nitrogen blowing tube, and the temperature was raised to 170 ° C. with stirring while blowing nitrogen into the flask. While maintaining the reaction temperature at 170 ° C., 10.4 parts of TDI was added dropwise over 1 hour. Further, 0.2 part of EMI catalyst was added simultaneously with the start of TDI dropping. Stirring was continued for 4 hours while maintaining the reaction temperature at 170 ° C. to obtain a polyoxazolidone resin.
Obtained infrared absorption spectrum of the polyoxazolidone resins, peak based on the stretching vibration of the carbonyl group derived from oxazolidone ring structure around 1752Cm ^-1, a peak based on the stretching vibration of isocyanurate derived carbonyl group 1709cm around ^-1 On the other hand, a peak (around 2270 cm ⁻¹ ) based on the stretching vibration of the isocyanato group was not observed. The results of IR analysis and the like of the obtained polyoxazolidone resin are shown in Table 1.
As shown in Table 1, in Comparative Examples 1 and 2, since a large amount of isocyanurate rings were produced, the polymerization stability was poor and the melt viscosity was high.

Using the polyoxazolidone resin obtained in Examples 1, 3, 4, and 5 and the polyoxazolidone resin obtained in Comparative Example 1, an insulating paint was prepared as follows.
To 100 parts of the above polyoxazolidone resin, 0.1 part of a hindered phenol as a stabilizer and 0.1 part of a diepoxy compound as a crosslinking agent were added to obtain a resin solution. For the purpose of reducing the residual catalyst in the resin solution, add 1 part of alumina oxide adsorbent per 100 parts of polyoxazolidone resin solution, stir sufficiently at room temperature, and filter with a filter of about 5 microns. To remove solvent-insoluble suspended matter. In order to adjust the concentration and viscosity of the obtained polyoxazolidone resin solution, DMAc was newly added as a diluent solvent to adjust to the target concentration to obtain an insulating paint.
Table 2 shows the evaluation results of evaluating these insulating paints and commercially available varnishes A and B.
As shown in Table 2, the cured product of the polyoxazolidone resin of Comparative Example 1 had low flexibility due to an increase in crosslink density due to the formation of isocyanurate rings.

  The polyoxazolidone resin obtained by the present invention is a thermoplastic resin, has a low melt viscosity, and is excellent in insulation, heat resistance, adhesiveness, and flexibility. Therefore, an adhesive, a sealing material, a molding material, a composite material, a laminate Excellent performance as a plate, sealing material, etc. In particular, it is excellent in insulation, heat resistance, adhesiveness, flexibility, and solder suitability as an varnish for enameled wire in the field of insulating paint, and can be used as an insulating paint at a high temperature level.

It is a chart of infrared absorption spectrum analysis of the polyoxazolidone resin obtained in Example 1 of the present invention. It is a chart of the H-nuclear magnetic resonance spectrum analysis of the polyoxazolidone resin obtained in Example 1 of the present invention. It is a chart of C-nuclear magnetic resonance spectrum analysis of the polyoxazolidone resin obtained in Example 1 of the present invention. It is a chart of infrared absorption spectrum analysis of the polyoxazolidone resin obtained in Example 5 of the present invention. It is a chart of the H-nuclear magnetic resonance spectrum analysis of the polyoxazolidone resin obtained in Example 5 of the present invention. It is a chart of the C-nuclear magnetic resonance spectrum analysis of the polyoxazolidone resin obtained in Example 5 of the present invention. It is a chart of the infrared absorption spectrum analysis of the polyoxazolidone resin obtained in Example 6 of the present invention. 2 is a chart of infrared absorption spectrum analysis of a polyoxazolidone resin obtained in Comparative Example 1.

Claims (8)

The following general formula (A)

(Wherein R ¹ is an organic compound group composed of carbon, hydrogen and oxygen having 2 to 20 carbon atoms, R ² is a hydrocarbon residue composed of carbon and carbon having 2 to 20 carbon atoms, R ³ is A polyoxazolidone resin represented by hydrogen or a hydrocarbon residue having 1 to 6 carbon atoms, B is a hydrocarbon residue having 1 to 12 carbon atoms, and n is an integer of 1 to 300. R ¹ is an aromatic hydrocarbon dialkylene ether, which is a residue bonded to the oxazolidone group by the two alkylene groups, R ² is an aromatic hydrocarbon residue, R ³ is hydrogen or a carbon number of 1 to 6 The polyoxazolidone resin according to claim 1, wherein B is an alkyl group having 1 to 6 carbon atoms.   The polyoxazolidone resin according to claim 1, wherein the diisocyanate alkyl carbamate compound (a) is reacted with the diepoxy compound (b) in the presence of a catalyst by using an excess of the diisocyanate alkyl carbamate compound (a). Production method.   The polyoxazolidone resin according to claim 3, which is reacted in such a range that the molar ratio (a) / (b) of the diisocyanate alkyl carbamate compound (a) to the diepoxy compound (b) is 1.01 to 1.1. Manufacturing method. The catalyst is represented by the following general formula (1)

(Wherein R is the same or different hydrocarbon group having 1 to 10 carbon atoms) or the following general formula (2)

Wherein R is the same or different hydrocarbon group having 1 to 10 carbon atoms, and Z ⁻ is a halogen anion, a hydroxy anion, an alkoxy anion, an aryloxy anion or a carboxy anion. A method for producing a polyoxazolidone resin according to claim 3 or 4.   An insulating paint containing the polyoxazolidone resin according to claim 1 or 2.   The insulating paint according to claim 6 comprising a crosslinking agent and / or a stabilizer.   An insulated wire having an insulating layer formed by applying and baking the insulating paint according to claim 6 or 7.

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