JPS6029736B2 - Manufacturing method of unsaturated polyester resin - Google Patents

Description

[Detailed description of the invention] This invention relates to a method for producing unsaturated polyester resins.

More specifically, it relates to a method for producing an unsaturated polyester resin that is particularly useful as an electrical insulating material with excellent heat resistance, chemical resistance, mechanical properties, and electrical properties, and is especially suitable as a varnish for impregnation, spraying, or molding. It is something. Typical examples of common unsaturated polyesters are those obtained by the reaction of polybasic acids such as maleic acid, fumaric acid, phthalic acid, or isophthalic acid or their acid anhydrides with polyhydric alcohols such as ethylene glycol and propylene glycol. It is a reaction product.

Desired unsaturated polyester resins are produced by dissolving this reaction product in vinyl or allyl monomers such as styrene, methyl methacrylate, and diallyl phthalate.
It is easy to handle and has excellent properties after curing, such as low viscosity, no volatile matter generation at room temperature or high temperature, and curing properties can be adjusted freely, and the cured resin has good mechanical properties, electrical properties, water resistance, acid resistance, It has oil resistance. In addition, because of its low price, it is used in a wide variety of fields, and its use as an electrical insulating material continues to expand due to its excellent insulating properties. By the way, with the recent demand for higher performance in electrical equipment due to demands for more compact size and increased power capacity, for example, coils used in electrical equipment are allowed to rise to higher temperatures, or There is an increasing desire for improved heat resistance for electrically insulating materials, such that they should be able to be used at higher ambient temperatures.

This trend is expected to continue in the future. However, while general unsaturated polyester resins have excellent electrical and mechanical properties, they are not necessarily satisfactory in terms of heat resistance, and the development of unsaturated polyester resins with even better heat resistance is desired. There is.

From this point of view, it is known that in order to modify unsaturated polyester resins, for example, heat-resistant monomers such as triallylysocyanurate and diarylic acid ester may be used, or unsaturated polyester itself may be modified with imide. It is being

However, the use of heat-resistant monomers has the problem of being expensive and not widely used. On the other hand, regarding imide modification, Japanese Patent Publication No. 51-8995 describes imide modification represented by the general formula (wherein, R is an aliphatic or aromatic divalent group, and R is an aliphatic divalent group). It has been disclosed that heat resistance can be increased by using a compound.

However, unsaturated polyesters imide-modified using such conventional techniques have some difficulty in compatibility with polymerizable monomers such as styrene, and compatibility with polymerizable monomers must be taken into consideration. . In addition, a monovalent imide group-containing alcohol represented by the general formula (b) or (m) (in the formula, R2 is hydrogen or a methyl group, and R3 is an alkylene group having 2 to 4 carbon atoms) is used. A technique for increasing the heat resistance of unsaturated polyester resins by using them together in the condensation formation of saturated polyesters was also shown in Samurai Kosho 45-2850y, but in this case, the imide group-containing alcohol was used as a monofunctional compound. It is difficult to obtain a cured product with sufficient heat resistance and mechanical properties because the chain length and molecular weight are decisive, and the content in the unsaturated polyester component is limited. There was a problem.

In view of this, the present inventors have conducted various studies to obtain an unsaturated polyester resin that maintains the excellent properties of conventional unsaturated polyester resins and has improved heat resistance. - A method for producing an unsaturated polyester resin by dissolving an unsaturated polyester obtained from a raw material containing a polycarboxylic acid containing an unsaturated dicarboxylic acid and a polyhydric alcohol in a radically polymerizable monomer, the raw material for the unsaturated polyester being For the total weight of , the general formula (
1) (wherein, R is a divalent hydrocarbon group such as an alkylene group or an arylene group, and -CH2-, 1○, 1S0
(representing a group selected from the group consisting of divalent hydrocarbon groups bonded by a divalent atomic group such as ) (wherein R2 is hydrogen or a methyl group, and R3 is an alkylene group having 2 to 4 carbon atoms) by containing 10 to 65% by weight of an imide group-containing alcohol. The present inventors have discovered a new fact that eliminates the above-mentioned drawbacks and also solves the problem of solubility of the resulting unsaturated polyester in radically polymerizable monomers, leading to the completion of the present invention.

That is, the present invention is characterized in that an imide group-containing dicarboxylic acid represented by the above general formula (1) and an imide group-containing alcohol represented by the general formula (b) or (m) are used together as a component of the unsaturated polyester. This makes it possible to improve the solubility of the resulting unsaturated polyester in polymerizable monomers, as well as improve its electrical properties, mechanical properties,
An object of the present invention is to provide an unsaturated polyester resin that provides a cured product with significantly improved heat resistance without impairing chemical resistance at all.

The unsaturated polyester resin obtained by the method of the present invention is extremely useful as a general heat-resistant material, especially an electrical insulating material, and especially as a heat-resistant varnish for impregnation, spraying, and molding.
To explain the production method of the present invention in a general and broad sense, an imide group-containing dicarboxylic acid represented by the above general formula (1), a monovalent imide group-containing alcohol represented by the general formula (0) or (m), A mixture consisting of a Q,8-unsaturated dicarboxylic acid, a monovalent or polyvalent saturated carboxylic acid or an acid anhydride thereof, and a monovalent or polyvalent alcohol, which is generally used as a raw material in the production of unsaturated polyester resins. The desired unsaturated polyester resin can be obtained by dissolving the unsaturated polyester obtained by reacting them in a radically polymerizable monomer.

In the present invention, the imide group-containing dicarboxylic acid represented by the above general formula (1) and the monovalent imide group-containing alcohol represented by the general formula (0) or (m) are such that the latter is 0 to 1 mole of the former. It is desirable to use it in a ratio of .3 to 4.0 mol, particularly preferably in a ratio of 0.5 to 3.0 mol.

Furthermore, the total content of these imide group-containing components is 10 to
65% (weight%, the same applies hereinafter), particularly preferably 20 to
Desirably, it is 55%. The reason for this is that if the molar ratio of the imide group-containing alcohol to 1 mole of the imide group-containing dicarboxylic acid is less than 0.3 mole, a problem arises in the solubility of the resulting unsaturated polyester in the polymerizable monomer; This is because if it exceeds 4.0 mol, the resulting cured resin product will not have sufficient heat resistance, and if the total content of the imide group-containing components is 10.
If it is lower than 65%, the heat resistance of the cured resin obtained is insufficient, and if it exceeds 65%, the solubility in the polymerizable monomer is insufficient, and the mechanical properties of the cured resin obtained are reduced. (Although heat resistance is sufficient), this is not preferable. The imide group-containing dicarboxylic acid used in the present invention includes, for example, 2 moles of trimellitic anhydride and the following diamines with a NfC ratio f2NH2, 2NkiCH2ki8NH2, QNfCHf4NH2, 4NkiCH
It can be easily obtained by imidization reaction with 1 mole of 2÷6N.

The imide group-containing dicarboxylic acids thus obtained can be used alone or in combination. Further, the imide-containing alcohol used in the present invention is, for example, tetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, or a simple substance of these acids. Alternatively, it can be easily obtained by subjecting the mixture to an imidization reaction with monoethanolamine, 1-aminopropan-3-ol, 1-aminobutan-4-ol, etc. alone or as a mixture.

These imide group-containing alcohols may be used alone or in combination. Examples of Q,8 monounsaturated dicarboxylic acids used in the present invention include maleic anhydride, fumaric acid, itaconic acid, citraconic acid, and mixtures thereof, and examples of polyvalent saturated carboxylic acids include:
For example, phthalic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, hexahydrophthalic acid, succinic acid, isophthalic acid, terephthalic acid, adipic acid, sebacic acid, trimellitic acid, Examples include pyromellitic acid, acid anhydrides thereof, and mixtures thereof.

The content of the above-mentioned Q,8 monounsaturated dicarboxylic acid in all the components constituting the unsaturated polyester influences the crosslinking density of the desired cured product of the unsaturated polyester resin, and thereby affects the cured product. In order to obtain better cured products, the following blending ratios are used to obtain better cured products. Further, examples of the polyhydric alcohol used in the present invention include ethylene glycol, propylene glycol, 1.4. -butanediol, 1,3-butanediol, diethylene glycol, dipropylene glycol,
Neobentyl glycol, hydrogenated bisphenol A, 1
．． Examples include 4-cyclohexanedimethanol, glycerin, trimethylolpropane, tris(2-hydroxyethyl)isocyanurate, and mixtures thereof.

When proceeding with the polycondensation reaction using each of the above components, the ratio of the number of carpoxyl groups to the number of hydroxyl groups in the reaction system is 0.
．． By adjusting the molecular weight within the range of 5 to 1.5, more preferably 0.8 to 1.2, favorable results can be obtained in terms of reaction and properties of the cured resin product. The reason for this is that if the ratio of the total number of hydroxyl groups to the total number of carboxyl groups in the reaction system is outside the above range, a large difference will occur between the number of hydroxyl groups and the number of carboxyl groups, making it difficult for the polycondensation reaction to proceed, resulting in the desired unsaturated polyester. This is because it becomes difficult to obtain. In this way, the proportions of each of the imide group-containing dicarboxylic acid, polycarboxylic acid containing Q,3-unsaturated dicarboxylic acid, imide group-containing alcohol, and polyhydric alcohol in the components to produce the unsaturated polyester are is limited.

The proportion of Q,B-unsaturated dicarboxylic acid or its anhydride in the carboxylic acid is a major factor in the properties of the resin as described above, but it is determined by the desired properties of the cured resin and is not particularly limited. Although it should not be
Desirably, it is about 40%, more preferably about 10 to 30%. This is because if the ratio is more than 40%, the crosslinking density of the cured product will be too high, making it hard and prone to cracking, and the curing shrinkage will also increase, causing negative effects, whereas if the ratio is less than 5%, the crosslinking density will be low. This is because if it becomes too much, the properties of the cured product may deteriorate. By the way, in order to obtain an unsaturated polyester using each of the above components, basically known conventional techniques can be used. Depending on your needs, you can select the method of adding the produced product to the reaction system for producing unsaturated polyester, or the method of pre-synthesizing it in the same reaction system for producing unsaturated polyester and then adding the remaining unsaturated polyester component. can.

In the latter case, for example, trimete acid anhydride is imidized with the above-mentioned diamine in a polyhydric alcohol component that produces an unsaturated polyester, and the imide group-containing dicarboxylic acid (if the reaction is further advanced, the imidization reaction is performed). ) is synthesized, an imide group-containing alcohol is produced by adding the above-mentioned corresponding amino alcohol and an acid anhydride, and then the remaining monovalent or polyvalent carboxylic acid containing the Q,B-unsaturated dicarboxylic acid is synthesized. and so on to obtain an unsaturated polyester. In this case, however, in order to avoid undesirable side reactions, it is preferable to add the remaining brewing ingredients, such as the Q,8-monounsaturated dicarboxylic acid or acid anhydride, to the reaction mixture after the imido groups have been sufficiently, preferably completely, formed. It should be kept in mind. In the method of the present invention, if necessary, an organic solvent such as xylene and a polymerization inhibitor such as hydroquinone are added to the reaction system, and the unsaturated polyester is prepared under an inert gas stream or, if necessary, under reduced pressure. It is produced by heating to the required temperature and reacting while distilling off water.

The reaction temperature is 80°C to 250°C, preferably 150°C.
The reaction temperature is within the range of ~220 qo, and the completion of the reaction can be determined, for example, by the amount of water removed, but it is preferably determined by measuring the acid value and viscosity of the ester, if necessary. Note that the acid value of the unsaturated polyester obtained by esterification is preferably 50 or less. Once the esterification has progressed to the desired stage as described above, the concentration is about 80 to 14,000, and if necessary, a polymerization inhibitor such as hydroquinone is added, and then mixed with a radically polymerizable monomer to form a uniform The desired unsaturated polyester resin can be obtained by dissolving the unsaturated polyester resin.

The unsaturated polyester resin produced as described above is, for example, penzoyl peroxide, di-t-butyl/
By using organic peroxides such as di-oxide, dicumyl/gu-oxide, t-butyl pardle benzoate, t-butyl perisooctoate, etc.
A desired cured product can be obtained.

At this time, curing may be appropriately accelerated using a polymerization initiator such as a combination of penzoyl peroxide and a tertiary amine. However, the cured product of the unsaturated polyester resin obtained by the method of the present invention has remarkable heat resistance, but does not have the excellent electrical properties and mechanical properties of conventionally known general unsaturated polyester resins. It is an extremely excellent product with a combination of various properties.

In addition to radical initiators such as the organic peroxides, polymerization inhibitors such as hydroquinone, quinone, and t-butylcatechol, organic cobalt compounds such as cobalt naphthenate, and if necessary, organic dyes and inorganic fillers may also be used. It can be used in a wide range of applications, such as electrical insulating materials, especially impregnating varnishes, spraying varnishes, molding varnishes, etc., and has extremely high industrial value. Next, the method of the present invention will be specifically explained with reference to Examples, Comparative Examples, and Reference Examples.

Reference Example 1 [Production of imide group-containing dicarboxylic acid] 192.1 g (1.0 mol) of trimellitic anhydride, 4.
99.1 g (0.5 mol) of 4-diaminodiphenylmethane was gradually heated from room temperature to 200°C while heating in a m-cresol 60 cell, and heating was continued at 200°C for 3 hours. .

During this time, powdery substances due to imidization begin to precipitate. Water produced by the reaction was removed from the system. After cooling, the precipitate was filtered, thoroughly washed with acetone, and then dried under reduced pressure to obtain N,N'-(methylene di-p-phenylene) bistrimeritimide in the form of a yellow powder. The yield is about 9
1%, m. p. 370 am, and the presence of imide groups and carboxylic acids was confirmed by IR absorption spectrum.
Reference example 2 [Production of imide group-containing alcohol] Mo/ethanolamine i22. Shigeru (2.0 mol) and tetrahydrophthalic anhydride 304. (2.0 mol) to 1
After gradually adding the mixture at a rate that maintained the reaction temperature at around 00 qo, heating was carried out at 200 qo for about 2 hours, and about 36 ml of condensed water was fractionated.

After the reaction was completed, the IR absorption spectrum of the solidified crude product showed no absorption due to the acid anhydride, but absorption due to the imide group, confirming that N-hydroxyethyltetrahydrophthalimide was obtained. This crude product could be used as it is in subsequent reactions, but it could be recrystallized with methanol, and the recrystallized product had an mp. 84-86qo
It was a white powder crystal. Example 13 Imide group-containing dicarboxylic acid 546 obtained in Reference Example 1 was placed in the four-piece flask.
．． 5g (1 mol) and neobentyl glycol 416.6
(4 moles) and continued heating under a stream of nitrogen gas at 200 qo while removing water generated during the reaction from the system.
After becoming a homogeneous system, imide group-containing alcohol 390. (2 moles), 152.1 g (1 mole) of tetrahydrophthalic anhydride, and 29 g (1 mole) of maleic anhydride.
4. (3 mol) was added and further heated at 200o○ for 3 hours.
After discharging the produced water by distilling it out of the system, the reaction was further continued at 210 to 220 oo to obtain an unsaturated polyester with an acid value of 32.5.

Add 0.9 g of hydroquinone to this reaction product, and add about 1
After cooling to 4,000 ℃, styrene 112 base was added and dissolved.

The resulting resin solution had a viscosity of 7.2 poise at 25 qo, was completely homogeneous, and did not form any precipitate upon standing. 1. t-butyl perbenzoate was added to 100 parts by weight of the resin solution. More anchor was added and stirred well to obtain a homogeneous solution. The solution obtained above was poured into a mold using two glass plates covered with PVA films and a silicone rubber baser with a thickness of 1 inch, and heated and cured at 130 pm for 2 hours to harden to a thickness of 1 inch. I got something.

The volume resistivity of this cured product is 3.6×1 at 220
60. The weight was 2.1×1 and 20 arc at 150° C., and the weight loss rate after heating in air at 220° C. for 1000 hours was 8.2%. In addition, the solution obtained above was wrapped around a round rod with a diameter of 6, and a length of 8 was obtained.
The helical coil adhesive strength in the bending test of the sample obtained by impregnating IJ Calcoil into the arc and curing for 2 hours at 130q0 was 9.8k9 at 2 years old and 2 at 13000.
．． It was 4k9.

Comparative Example 1 3 546.5 g (1 mol) of the imide group-containing dicarboxylic acid obtained in Reference Example 1 and 624.9 g (6 mol) of neobentyl glycol were placed in the four-walled flask, and the reaction was carried out in the same manner as in Example 1. After becoming a homogeneous solution, 152.1 g (1 mol) of tetrahydrophthalic anhydride and 294.1 g (1 mol) of maleic anhydride were added. (3 mol) was added thereto, and the reaction was continued in the same manner as in Example 1 to obtain an unsaturated polyester with an acid value of 19.5.

After adding 0.85 g of hydroquinone to this reaction product, 1006 g of styrene was added and an attempt was made to dissolve it, but it did not dissolve completely, and the solution taken out by filtration also became precipitated by standing, resulting in a uniform resin. Could not get solution. Example 2 3 273.3 g (0.5 mol) of the imide group-containing dicarboxylic acid obtained in Reference Example 1 and 48.3 g (0.5 mol) of the imide group-containing alcohol obtained in Reference Example 2 were placed in the four-cell flask. Total (0.25 mol), isophthalic acid 4 moth. (3 moles) and 512.1 g (8.25 moles) of ethylene glycol, and 0.0 g of tetra-n-butyl titanate as an esterification catalyst. After adding nutrients, the heating process was continued at 190 qo under a stream of nitrogen gas while removing the produced water from the system for about 2. After the solution becomes uniform between the batches, 3 batches of maleic anhydride are added. He (4 moles)
was added, and while distilling the produced water out of the system, 190
The mixture was heated at 0.00 qo and the reaction was continued at 210 to 220 qo to obtain an unsaturated polyester with an acid value of 17.5.

0.5 g of hydroquinone was added to the reaction product, and after cooling to about 130° C., Styrene 101 chicks were further added and dissolved.

The resulting resin solution had a viscosity of 3.5 poise at 25°C and was completely uniform. 10 parts of this resin solution
To this, add 0.5 part of t-butyl perbenzoate,
Stir well to obtain a homogeneous solution. A casting plate having one side thickness was obtained in the same manner as in Example 1 using the solution.

The volume resistivity of this casting plate is 4.
It was 2.1 x 1 and 60.Arc, and 2.1 x 1 and 50.A after soaking in water for 10 days. Furthermore, when the bait was heated for 100 hours at 220 qC in air, the heating weight reduction rate was 11.2%. Example 3 99.1 g (0.5 mol) of 4,4'-diaminodiphenylmethane, 192.1 g (1 mol) of trimellitic anhydride, and 54 mol of 1.4-butanediol were placed in a four-piece flask.
After charging 0.7 g (6 mol) and dissolving it by raising the temperature from room temperature to 165 qo under a nitrogen gas flow, 180 to 190 qo
When the mixture was heated at oo for 1 hour in a dark frame, yellow starch due to imidization was precipitated.

Furthermore, while distilling the generated water out of the system,
After heating for 4 hours at 0.00C, a homogeneous solution was obtained.
After that, it was cooled to 150:00, and monoethanolamine 3
0. Key (0.5 mol), methyltetrahydrophthalic anhydride 415. Add cough (2.5 mol), 150-1600
After heating for 30 minutes at 0°C, heating was continued for 1 hour at 210° to 210°C while removing the generated water from the system. Next, 348.1 g (3 mol) of fumaric acid was added and the reaction was continued at 200 to 21,000 to obtain an unsaturated polyester having an acid value of 14.5. After adding 0.3 g of hydroquinone to the reaction product and cooling it to about 130 qo,
Styrene 55 spots were added and dissolved.

The resulting resin solution had a viscosity of 5.2 poise at 2500°C and was completely homogeneous. To 10 parts of this resin solution, 1.0 part of penzoyl peroxide was added and stirred well to obtain a homogeneous solution. The obtained solution was prepared in Example 1.
By pouring into a mold similar to the above and curing at 120 CO for 3 hours, a cast plate with a thickness of one wall was obtained.

The volume resistivity of this casting plate is 3.2×1 at 2C
and 60, set to 15000, and 2.4 x 1 and 20.
It was restrained. Further, when heated in air at 220° C. for 1000 hours, the heating weight reduction rate was 9.4%. Example 4 3 Into the four-piece flask were 100.1 g (0.5 mole) of 4,4'-diaminodiphenyl ether, 192.1 g (1 mole) of trimellitic anhydride, and 270 g (1 mole) of 1.4-butanediol. fin (3 moles), and neobentyl glycol 312. Chicks (3 mol) were prepared and treated with 0.0% tetra-iso-propyl titanate. After that, add it to the room under a nitrogen gas flow for 200 minutes.
qo for 3 hours while heating the water while removing the water from the system.After becoming a homogeneous solution, it was cooled to 15,000, and 91.6 g (1.5 mol) of monoethanolamine and endomethylene were added. Tetrahydrophthalic anhydride 246.
After adding 3g (1.5 mol) and heating at 150 to 160 qo for 1 hour, heating was continued at 200 qo for about 1 hour while distilling off the water produced, and then isophthalic acid 498
．． (3 mol) was added, and the reaction was continued for about 2 hours until the system became homogeneous.

Then maleic anhydride 294. (3 mol) was added, and while continuing to distill off the water produced, the reaction was continued at 200 o'clock for 1 hour, then the temperature was raised to 210 o'clock, and the reaction was continued until the acid value was 23.
An unsaturated polyester of No. 1 was obtained. 0.0% hydroquinone was added to the reaction product obtained above. A rudder was added, and after cooling to about 130 oo, 95% styrene was added and dissolved.

The resulting resin solution was completely homogeneous and had a viscosity of 11.2 poise at 25 qo. 0.5 parts by weight of t-butyl looper benzoate per 10 parts by weight of this resin solution.
of the mixture and stirred well to obtain a homogeneous solution. The obtained solution was applied onto a tin plate, heated and cured at 12yo for 2 hours, and then peeled off to obtain a film with a thickness of about 0.05 mm. This film was strong and highly flexible. Further, when this film was heated in air at 220° C. for 1000 hours, the heating weight reduction rate was 9.8%. Example
5 Monoethanolamine in Example 491. Foundation (1
．． 5 mol) instead of 1-aminopropane-3ol 1
12. The viscosity of the resin solution obtained in exactly the same manner as in Example 4 except that 1.5 mol of chloride (1.5 mol) was used was 10.1 at 25 qo.
It was a completely homogeneous solution.

Claims (1)

[Claims] 1. An unsaturated polyester resin is produced by dissolving an unsaturated polyester obtained from a raw material containing a polycarboxylic acid including an α,β-unsaturated dicarboxylic acid and a polyhydric alcohol in a radically polymerizable monomer. In the method of and -CH_2-, -O-, -
(representing a group selected from the group consisting of divalent hydrocarbon groups bonded by divalent atomic groups such as SO_2-) and an imide group-containing dicarboxylic acid represented by general formula (II) or general formula (III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_2 is hydrogen or a methyl group, R_3 is an alkylene group having 2 to 4 carbon atoms) A method for producing an unsaturated polyester resin, characterized in that it contains 65% by weight. 2. The method for producing an unsaturated polyester resin according to claim 1, wherein 0.3 to 4.0 moles of the imide group-containing alcohol are used per 1 mole of the imide group-containing dicarboxylic acid. 3. The method for producing an unsaturated polyester resin according to claim 1 or 2, wherein a pre-synthesized imide group-containing dicarboxylic acid is used in the unsaturated polyester production reaction system. 4. The method for producing an unsaturated polyester resin according to any one of claims 1 to 3, wherein a pre-synthesized imide group-containing alcohol is used in the unsaturated polyester production reaction system. 5. The method according to any one of claims 1 to 4, wherein a reaction product obtained from trimellitic anhydride and 4,4'-diaminophenylmethane is used as the imide group-containing dicarboxylic acid. Method for producing unsaturated polyester resin. 6. Any one of claims 1 to 5 in which a reaction product obtained from monoethanolamine and tetrahydrophthalic anhydride is used as the imide group-containing alcohol represented by general formula (II). A method for producing the described unsaturated polyester resin. 7. Claims 1 or 2, wherein the imide group-containing dicarboxylic acid, the imide group-containing alcohol, and the materials necessary for producing the unsaturated polyester are sequentially charged into one reaction vessel to synthesize the unsaturated polyester. A method for producing an unsaturated polyester resin as described in Section 1.