JPH08311180A - Production of unsaturated polyester resin - Google Patents

Abstract

PURPOSE: To produce an unsaturated polyester resin in a relatively short time by using inexpensive raw materials, excellent in curing properties, having a styrene content to be readily reduced. CONSTITUTION: This method for producing an unsaturated polyester resin comprises (1) a process for reacting a dicarboxylic acid consisting essentially of an α,β-dicarboxylic acid and/or its anhydride and/or its anhydride with a dihydric alcohol in the molar ratio of (1.5-2.5):1 at 155-230 deg.C, (2) a process for adding a dicarboxylic acid anhydride and an alkylene oxide in the presence of the reaction product and carrying out a ring-opening addition polymerization to give an unsaturated oligoester, (3) a process for successively subjecting the unsaturated oligoester to polycondensation to give an unsaturated polyester and (4) a process for dissolving the unsaturated polyester in a polymerizable unsaturated monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an unsaturated polyester resin which is a combination of a ring-opening addition polymerization method and a polycondensation method and which is low in cost and excellent in curability and water resistance of the cured product.

[0002]

2. Description of the Related Art Conventionally, as a method for producing an unsaturated polyester, a dehydration polycondensation reaction of an α, β-unsaturated dicarboxylic acid or a dicarboxylic acid containing an anhydride thereof, or an anhydride thereof and a polyhydric alcohol It is called legal) and α, β-
A ring-opening addition polymerization reaction (hereinafter referred to as an oxide method) of a dicarboxylic acid anhydride containing an unsaturated dicarboxylic acid anhydride and an alkylene oxide is mainly performed. Compared with the condensation method, the oxide method has advantages such as a shorter reaction time and a higher product yield because condensation water is not generated.
On the other hand, the resulting unsaturated polyester resin is markedly colored, emits a foul odor, is inferior in storage stability, and the copolymerization reactivity between the resulting unsaturated polyester and the polymerizable unsaturated monomer is low, so that curability and curing There are many drawbacks such as poor mechanical properties and water resistance. As a method for improving these drawbacks, JP-A-54-86594 and JP-A-55-605.
No. 23, proposes a method combining an oxide method and a condensation method. According to this method, the coloration, malodor and storage stability of the resulting unsaturated polyester resin are slightly improved, but the curability, mechanical properties of the cured product and water resistance are better than those obtained by the condensation method. Apparently insufficient. Further, Japanese Patent Laid-Open No. 59-45317 discloses that
A method for improving the curability of unsaturated polyester resin and the physical properties of the cured product by combining the oxide method and the condensation method has been shown, but in the case of use at low temperature and adaptation to high cycle, the condensation method is still available. The problem is that it is inferior to the unsaturated polyester resin produced in 1.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a copolymerization reaction with a polymerizable unsaturated monomer which is equal to or more than that obtained by the condensation method in the production of unsaturated polyester by combining the oxide method and the condensation method. The object of the present invention is to produce an unsaturated polyester resin having good properties, and as a result, excellent curability, mechanical properties of the cured product and water resistance. Another object of the present invention is to produce an unsaturated polyester resin from a raw material which has a short reaction time and a low cost as compared with the condensation method. Still another object of the present invention is to produce a low styrene resin having a low styrene volatilization amount in a work environment without deteriorating the physical properties.

[0004]

DISCLOSURE OF THE INVENTION As a result of intensive studies for achieving the above-mentioned object, the present inventors have found that dicarboxylic acid having a high copolymerization reactivity with a polymerizable unsaturated monomer, 1.5 to 2.5. Moles and 1 mole of a dihydric alcohol are used as the main component of an initiator to prepare an unsaturated oligoester by an oxide method, and then polycondensation of the oligoester is used to obtain a trans structure It was found that the unsaturated polyester resin in which the saturated dicarboxylic acid unit is delocalized has excellent curability, mechanical properties of the cured product, and water resistance as compared with conventional resins. That is, the present invention relates to an α, β-unsaturated dicarboxylic acid and / or
Or a dicarboxylic acid containing its anhydride as a main component and /
Alternatively, the anhydride and the dihydric alcohol are mixed with each other in the range of 1.5 to 2.
Reacting at a molar ratio of 5: 1 at 155 to 230 ° C.
(1), a step of adding dicarboxylic acid anhydride and alkylene oxide in the presence of the reaction product, ring-opening addition polymerization to obtain an unsaturated oligoester (2), and then polycondensing the unsaturated oligoester It is a process for producing an unsaturated polyester resin comprising a step (3) of obtaining an unsaturated polyester and a step (4) of dissolving the unsaturated polyester in a polymerizable unsaturated monomer.

In the step (1), a dicarboxylic acid containing an α, β-unsaturated dicarboxylic acid and / or its anhydride as a main component and / or its anhydride and a dihydric alcohol are mixed with 1.
The reaction is carried out in a molar ratio of 5 to 2.5: 1, preferably 1.8 to 2.2: 1. At this time, the total of the α, β-unsaturated dicarboxylic acid and its anhydride is 60 mol% or more, preferably 80 mol% or more, more preferably 100 mol% of the total of the dicarboxylic acid and its acid anhydride. , 60 mol%
If it is less, the curability of the resin may decrease. Further, when the molar ratio of dicarboxylic acid or its anhydride and dihydric alcohol is more than 1.5: 1, the amount of ether bond in the product of the step (2) increases, resulting in unsaturation. The mechanical properties of the cured polyester resin deteriorate. In addition, this molar ratio is 2.5: 1 to 2
If the amount of polyhydric alcohol is low, it may be difficult to stir,
Unsaturated polyester obtained by unreacted acid may be turbid, and the target unsaturated polyester resin cannot be produced. This reaction is usually carried out with heating in an inert gas. The reaction temperature is the presence or absence of acid anhydride,
It is appropriately selected depending on the type of dihydric alcohol and dicarboxylic acid. Examples of the α, β-unsaturated dicarboxylic acid and its anhydride used in step (1) include fumaric acid, maleic acid,
Examples thereof include itaconic acid, citraconic acid, maleic anhydride, itaconic anhydride, citraconic anhydride and the like, but fumaric acid and maleic anhydride are preferably used, and fumaric acid is more preferably used. Dicarboxylic acids other than α, β-unsaturated dicarboxylic acids and their anhydrides include orthophthalic acid, terephthalic acid, isophthalic acid, adipic acid, tetrahydrophthalic acid, hexahydrophthalic acid, het acid, succinic acid, phthalic anhydride, Examples thereof include tetrahydrophthalic anhydride, succinic anhydride, etc., but phthalic anhydride and tetrahydrophthalic anhydride are preferably used. As the dihydric alcohol, ethylene glycol, diethylene glycol, triethylene glycol,
Propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol, 2,2,4-trimethyl-
1,3-pentanediol, 1,6-hexanediol,
Examples of hydrogenated bisphenol A include ethylene glycol, diethylene glycol and propylene glycol, with diethylene glycol being most preferred. A catalyst may be used in the reaction of the step (1) if necessary. Examples of the type of catalyst used include N-ethylmorpholine and piperazine, and the amount of the catalyst used is 0.0 of an α, β-unsaturated dicarboxylic acid.
It is 2 to 1.0% by weight, preferably 0.1 to 0.5% by weight. The reaction time is usually 10 to 200 minutes, preferably 15 to
It takes about 100 minutes. By the reaction of the step (1), a reaction product containing a diester having carboxyl groups at both ends as a main component can be obtained. When a cis α, β-unsaturated dicarboxylic acid or its anhydride is used in the reaction of step (1), its content is 5 to 30% by weight, preferably 10 to 2%.
155 to 230 ° C., preferably 160 to 220, in the presence of 0% by weight of a saturated or aromatic dicarboxylic acid such as adipic acid or phthalic anhydride or an anhydride thereof.
By carrying out the heat treatment at ℃, the ratio of the trans isomer of the α, β-unsaturated dicarboxylic acid unit in the final unsaturated polyester can be at least 85 mol% and usually 90 mol% or more.

In step (2), the reaction product obtained in step (1) is used as an initiator for ring-opening addition polymerization, and a dicarboxylic acid anhydride, preferably a dicarboxylic acid other than α, β-unsaturated dicarboxylic acid anhydride. Anhydrous is added, and alkylene oxide is fed in an inert gas to carry out ring-opening addition polymerization. This dicarboxylic acid anhydride is added in an amount such that the amount of the dihydric alcohol used in step (1) is 10 to 50 mol%, preferably 25 to 40 mol% of the total amount of dicarboxylic acid. At this time, a catalyst may be used to suppress the by-product of ether bond and increase the reaction rate. Whether to use a catalyst or not is determined by what is important in the performance of the unsaturated polyester resin to be produced. Generally, it is desirable to use a catalyst when shortening the reaction time and placing importance on the mechanical properties of the cured product, and not using a catalyst when placing importance on resin hue, raw material cost reduction, and low styrene reduction. .

Examples of dicarboxylic acid anhydrides other than α, β-unsaturated dicarboxylic acid anhydrides include phthalic anhydride and
Tetrahydrophthalic anhydride, succinic anhydride and the like are preferable. The α, β-unsaturated dicarboxylic acid anhydride exemplified in the step (2) or the step (1) may be used, but other ones are preferable. Examples of the alkylene oxide include ethylene oxide, propylene oxide, styrene oxide, epichlorohydrin, and glycidyl compounds represented by allyl glycidyl ether and benzoic acid glycidyl ester, and propylene oxide is preferable. The feed amount of alkylene oxide is usually such that the total number of moles of dihydric alcohol and alkylene oxide is 1 to 2 times the amount of dicarboxylic acid ester units in the final unsaturated polyester, but the feed rate of alkylene oxide is
Since the amount of ether bond produced by the reaction between the alkylene oxide and the reactive terminal hydroxyl group varies depending on the presence or absence of the catalyst, the type and amount thereof, the reaction pressure, etc., the proper alkylene oxide feed amount can be obtained in the step (2). The difference between the acid value and the hydroxyl value of the unsaturated oligoester is not so large that the difference is preferably 30 or less. Feeding of the alkylene oxide is usually carried out for about 30 minutes to 4 hours while maintaining the reaction temperature at 110 to 220 ° C, preferably 120 to 200 ° C. As the catalyst, 3 such as triethylamine and N-ethylmorpholine are used.
Quaternary ammonium salts such as secondary amines, triethylbenzylammonium chloride, tetraethylammonium bromide and tetramethylammonium carbonate, phosphorus compounds such as triphenylphosphine, butyltriphenylphosphonium bromide and tetraphenylphosphonium bromide, zirconium octylate, zinc acetate, etc. The metal soap compound can be exemplified, but a quaternary ammonium salt or a quaternary phosphonium salt is preferably used. The amount of the catalyst used is 0.005 to 2% by weight, preferably 0.01 to 0.5% by weight, based on the total amount of the dicarboxylic acid and the dicarboxylic acid anhydride. When the amount of the catalyst is large, the coloring of the unsaturated polyester generally obtained is large, and when the amount of the catalyst is small, the amount of ether bond produced is increased, so that the mechanical properties of the cured product of the unsaturated polyester resin may be deteriorated. .

In step (3), dehydration polycondensation is carried out by heating at 190 to 220 ° C. while blowing an inert gas into the unsaturated oligoester which is the reaction product of step (2) to give an acid value of 1
5-40 mg KOH / g unsaturated polyester is obtained. The reaction time is usually 1 to 4 hours. By this reaction, not only an appropriate molecular weight but also an unsaturated bond which is offset to the center of the molecular chain during the ring-opening addition polymerization reaction can be dispersed in the molecular chain by a transesterification reaction.

In step (4), the unsaturated polyester obtained in step (3) is mixed with a polymerizable unsaturated monomer to give an unsaturated polyester resin. At this time, a method of adding and mixing the unsaturated polyester into the polymerizable unsaturated monomer while controlling the temperature under stirring, and stirring the unsaturated polyester in the unsaturated polyester cooled to 150 ° C. or less Any mixing method such as a method of adding and mixing to As the polymerizable unsaturated monomer used here, styrene, chlorostyrene, α-methylstyrene, vinyltoluene, vinylbenzenes such as divinylbenzene, methyl acrylate,
Methyl methacrylate, glycidyl methacrylate,
Examples thereof include (meth) acrylic acid esters such as ethylene glycol dimethacrylate, polyvalent allyl compounds such as diallyl phthalate, dimethallyl phthalate and triallyl cyanurate, and one or more of these monomers. Although a mixture of the above can be used, styrene alone is preferably used. In general, unsaturated polyester resins have an appropriate viscosity during work and a viscosity of 450 to 550 mPa · s at 25 ° C in order to obtain a cured product with excellent physical properties.
5 to 100 parts by weight of unsaturated polyester to obtain s
A polymerizable unsaturated monomer such as a styrene monomer is added in an amount of 3 to 65 parts by weight, and the unsaturated polyester obtained by the method of the present invention should be a resin having a similar viscosity when added in an amount of 50 parts by weight or less. You can In addition, the cured product of the resin of the present invention has far superior mechanical properties and water resistance as compared with conventional low styrene resins.

[0010]

INDUSTRIAL APPLICABILITY The unsaturated polyester resin of the present invention can be cured by the same means as conventionally known unsaturated polyester resins, and can be used for paints, castings, putties, resin concrete, fiber reinforced unsaturated polyester resins, etc. Can be used for various purposes. The unsaturated polyester resin of the present invention, although capable of being produced in a short time, has a high trans isomer ratio α, β-unsaturated dicarboxylic acid ester unit, thus exhibiting excellent curability and a poor molding environment, Even under molding conditions, it exhibits high water resistance and mechanical properties. Further, since the unsaturated polyester resin of the present invention can generally be produced by selecting a raw material having a low market price, it has excellent cost performance and strong market competitiveness. In particular, the unsaturated polyester resin of the present invention is capable of efficiently producing a low-viscosity unsaturated polyester while maintaining high curability, so that it is easy to reduce the styrene content and is required to have an improved work environment. It is suitable for use in open molding such as up molding and spray up molding.

[0011]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited by these examples. All "parts" in Examples and Comparative Examples represent parts by weight. Abbreviations used in Examples and Comparative Examples are as follows. Fumaric acid FA Maleic anhydride MAN Phthalic anhydride PAN Tetrahydrophthalic anhydride THPAN Ethylene glycol EG Diethylene glycol DEG Propylene glycol PG Propylene oxide PO triethylbenzylammonium chloride TEBAC Tetraphenylphosphonium bromide TPP-PB N-ethylmorpholine N-EM octyl zirconium Oc -Zr hydroquinone HQ styrene St

Example 1 (Production of Unsaturated Polyester A) FA1184 g, DE in a reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube and a partial refluxer equipped with a thermometer at the top of the tower.
G547 g and HQ 0.17 g were charged, the inside of the reactor was sufficiently replaced with nitrogen gas, and the temperature was raised with stirring. 210
The reaction was carried out for 1 hour and 20 minutes from the condensation water distillation while maintaining the temperature below ℃. PAN1007g and TEBAC were added to this reaction mixture.
After adding 1.1 g and stirring for several minutes, 160-200
While maintaining the temperature at 850 ° C., 850 g of PO was fed over 1 hour and 30 minutes. After the PO feed was completed, the reaction was continued for 20 minutes. The acid value of the resulting unsaturated oligoester is 60 mg KO
H / g and hydroxyl value were 73 mgKOH / g. The unsaturated oligoester was polycondensed at 210 ° C. for 3 hours to obtain an unsaturated polyester having an acid value of 36 mgKOH / g. As a result of analyzing this unsaturated polyester by NMR, the charged FA
Of these, 95 mol% was the trans form. Examples 2 to 5 (Production of Unsaturated Polyesters B to E) In the same manner as in Example 1, the raw materials shown in [Table 1] were used for the reaction, and the unsaturated polyester B as shown in [Table 1].
~ E were produced.

Comparative Example 1 (Production of Unsaturated Polyester F) MAN1 was placed in a reactor equipped with a stirrer, a thermometer and a nitrogen inlet tube.
000g, PAN1007g, EG106g and HQ
0.16 g was charged and reacted at 120 to 150 ° C. for about 1 hour. To this reaction mixture product, 12% Oc-Zr 2g was added, PO1027g was fed over about 1 hour and 30 minutes while keeping the temperature below 200 ° C, and the acid value was 35mgKOH / g.
Of unsaturated polyester was obtained. As a result of NMR analysis, 70 mol% of the charged MAN was in the trans form. Comparative Example 2 (Production of Unsaturated Polyester G) PAN was placed in a reactor equipped with a stirrer, a thermometer, and a nitrogen inlet tube.
1007 g, MAN 1000 g, DEG 547 g and HQ 0.16 g were charged and the system was replaced with an inert gas,
The reaction was carried out at 120 ° C for 15 minutes. PO to this reaction mixture
958 g were fed in about 60 minutes. At this time, the reaction temperature was 120 to 171 ° C. After finishing the PO feed,
The reaction was continued for about 15 minutes to obtain an unsaturated oligoester having an acid value of 83 mgKOH / g and a hydroxyl value of 80 mgKOH / g. The unsaturated oligoester was subjected to polycondensation at 210 ° C. for 4 hours to obtain an unsaturated polyester having an acid value of 34 mgKOH / g. As a result of NMR analysis, the MAN prepared
Of these, 78 mol% was the trans form.

Comparative Example 3 (Production of Unsaturated Polyester H) In a reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube and a partial reflux condenser equipped with a thermometer at the top, 1007 g of PAN,
EG211g and HQ 0.17g were prepared, and it was made to react at 120-140 degreeC for 20 minutes, blowing an inert gas. This reaction mixture was mixed with MAN 120 ° C. melt 1
000 g was added, and the mixture was stirred until the reaction mixture became uniform and generation of reaction heat was not observed. Then, while controlling the reaction temperature so as not to exceed 190 ° C, PO10
37 g was fed in 70 minutes. After the PO feed is completed, the reaction is continued for about 20 minutes, and the acid value is 77 mgKOH / g and the hydroxyl value is 8
6 mg KOH / g of unsaturated oligoester was obtained. This unsaturated oligoester was subjected to polycondensation at 210 ° C. for about 5 hours to obtain an unsaturated polyester having an acid value of 33 mgKOH / g. As a result of NMR analysis, 84 mol% of the charged MAN was in the trans form. Comparative Example 4 (Production of Unsaturated Polyester I) In a reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube and a partial reflux device equipped with a thermometer at the top of the column, PAN1007g,
MAN 1000 g, DEG 547 g, PG 969 g and HQ 0.16 g were charged and polycondensation was carried out at 200 ° C. for 12 hours while blowing an inert gas to obtain an unsaturated polyester having an acid value of 35 mg KOH / g. NM
As a result of analysis by R, 81 mol% of the charged MAN
Was a trans form. Comparative Example 5 (Production of Unsaturated Polyester J) In a reactor equipped with a stirrer, a thermometer, a nitrogen introducing pipe and a partial reflux device equipped with a thermometer at the top of the column, PAN1007g,
FA1184 g, DEG547 g, PG969 g and HQ0.16 g were charged, and polycondensation was carried out at 200 ° C. for 12 hours while blowing an inert gas into the system to obtain an unsaturated polyester having an acid value of 34 mg KOH / g. NM
As a result of analysis by R, 90 mol% of the charged FA was in the trans form.

Examples 6 to 10 With respect to 100 parts of five unsaturated polyesters of A to E,
Unsaturated polyester resins a to e were prepared by adding 0.015 parts of HQ and the amount of St shown in [Table 2]. [Table 2] shows properties of these resins and JIS K 6901 room temperature curing characteristics when 0.4 part of 6% cobalt naphthenate and 1.0 part of 55% methyl ethyl ketone peroxide were added to 100 parts of the resin. To 100 parts of these resins, 0.4 part of 6% cobalt naphthenate and 1.0 part of 55% methyl ethyl ketone peroxide were added and cured at room temperature, and post-cured at 60 ° C. for 1 hour and 100 ° C. for 3 hours. JIS K 6911 tensile test and JIS K 7207 load deflection temperature measurement results of cast plate, and 80 parts of the above resin to 20 parts of styrene and 20 parts of Aerosil
0 (Japan Aerosil Co., Ltd.) 1.0 part and 6% cobalt naphthenate 0.4 part are mixed to prepare a thixotropic resin, 55%
Add 1.0 parts of methyl ethyl ketone peroxide,
[Table 4] shows the results obtained by laying a glass mat 3 ply of 450 g / m ³ and curing it at room temperature and immersing it in water for 24 hours.

Comparative Examples 6-10 With respect to 100 parts of five types of unsaturated polyesters FJ,
0.015 parts of HQ and the amount of St shown in [Table 3] were added to obtain unsaturated polyester resins f to i. [Table 3] shows the properties of these resins and JIS K 6901 room temperature curing characteristics when 0.4 part of 6% cobalt naphthenate and 1.0 part of 55% methyl ethyl ketone peroxide were added to 100 parts of the resin. To 100 parts of these resins, 0.4 part of 6% cobalt naphthenate and 1.0 part of 55% methyl ethyl ketone peroxide were added and cured at room temperature, and post-cured at 60 ° C. for 1 hour and 100 ° C. for 3 hours. JIS K 6911 tensile test and JIS K 7207 load deflection temperature measurement results of cast plate, and 80 parts of the above resin to 20 parts of styrene and 20 parts of Aerosil
0 (Japan Aerosil Co., Ltd.) 1.0 part, 6% cobalt naphthenate 0.4 part are mixed to make a thixotropic resin, 55%
Add 1.0 parts of methyl ethyl ketone peroxide,
Laminated on 450 g / m ³ of glass mat 3 plies, cured at room temperature and immersed in water for 24 hours. [Table 5]
Shown in

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

From the comparison between the above examples and comparative examples, it is clear that the following will be described. 1) Resin f synthesized by the oxide method of Comparative Example 1
Is more colored than the resin of the present invention, and is clearly inferior in curability and mechanical properties, especially in deflection temperature under load and water resistance. 2) The resin obtained in Comparative Example 2 is disclosed in JP-A-54-8659.
It was synthesized according to the method of No. 4, and because it has no catalyst, the colorability is improved, but the curability and water resistance are inferior to those of the present invention. 3) Resin h obtained in Comparative Example 3 is described in JP-A-59-4531.
It was synthesized according to the method of 7, and the curability is slightly improved as compared with the resin of this method, but it is still insufficient.
Water resistance is not improved either. 4) Resins i and j obtained in Comparative Examples 4 and 5 were synthesized by a condensation method and were inferior in water resistance to the resins a and b of the present invention having a composition close to those of the resins a and b, and There is a disadvantage that it takes a considerably long time to manufacture as compared with the above method.

Claims (5)

[Claims] 1. A dicarboxylic acid containing an α, β-unsaturated dicarboxylic acid and / or its anhydride as a main component and / or its anhydride and a dihydric alcohol are added in an amount of 1.5 to 2.5: 1.
(1) in which the reaction is carried out at a molar ratio of 155 to 230 ° C., a dicarboxylic acid anhydride and an alkylene oxide are added in the presence of the reaction product, and ring-opening addition polymerization is performed to obtain an unsaturated oligoester (2). , And then polycondensing the unsaturated oligoester to obtain an unsaturated polyester
A method for producing an unsaturated polyester resin, which comprises (3) and a step (4) of dissolving the unsaturated polyester in a polymerizable unsaturated monomer. 2. The production method according to claim 1, wherein in the step (1), one or more selected from fumaric acid, maleic acid and maleic anhydride are used as the α, β-unsaturated dicarboxylic acid or its anhydride. . 3. The reaction of step (1) comprises dicarboxylic acid and / or its anhydride and dihydric alcohol in the range of 1.8 to 2.2: 1.
The production method according to claim 1, which is carried out at a molar ratio of 160 to 220 ° C. 4. As the dicarboxylic acid anhydride of step (2), α,
The method according to claim 1, wherein a dicarboxylic acid anhydride other than the β-unsaturated dicarboxylic acid anhydride is used. 5. The process according to claim 4, wherein the dicarboxylic acid anhydride in step (2) is phthalic anhydride and / or tetrahydrophthalic anhydride.