JPS5968327A - Production of unsaturated polyester - Google Patents

Abstract

PURPOSE:To produce an unsaturated polyester excellent in storage stability, etc., by reacting dimethyl terephthalate with a polyalcohol in the presence of a catalyst and then reacting the product with an unsaturated dibasic acid and a polyalcohol in the presence of a solvent. CONSTITUTION:Dimethyl terephthalate and a polyalcohol (e.g., ethylene glycol or propylene glycol) are heated to a temperature of 200-210 deg.C in the presence of a transesterification catalyst (e.g., lead acetate or manganese chloride) to effect an esterification reaction. After cooling, the reaction mixture is mixed with an unsaturated dibasic acid (e.g., maleic or fumaric acid), a polyalcohol (e.g., neopentyl glycol), a solvent (e.g., xylene or toluene) and, if necessary, a saturated dibasic acid (e.g., phthalic acid). The resulting mixture is heated again to about 180- 230 deg.C to effect the second stage reaction to obtain the purpose unsaturated polyester.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a non-Fa+", Japanese polyester, and its purpose is particularly to improve storage stability.

An object of the present invention is to provide a method for easily producing an unsaturated polyester having excellent chemical resistance and hot water resistance.

Traditionally, unsaturated polyesters are maleic acid.

unsaturated carboxylic acids or their anhydrides, such as fumaric acid; It is produced by the condensation reaction of a mixture substituted with ethylene glycol, glycol such as ethylene glycol, globylene glycol, and diglobylene glycol.

However, this is the most common type of unsaturated polynisder, such as maleic anhydride.

Unsaturated 11th polyester obtained from phthalic anhydride and propylene glycol suffers from poor chemical resistance and hot water resistance, which naturally limits its range of use. The current problem is that it cannot be used in a wide range of applications. Besides this, of course.

There is a so-called bisphenol-based non-11 hydrated polyester, but although it has poor chemical resistance and hydrothermal resistance, it has extremely low cost and industrial productivity.

There are many problems with marketability and it is not common.

The present inventors found that it is extremely effective to use terephthalic acid as a saturated dicarboxylic acid, and by reacting an unsaturated dibasic acid, a polyhydric alcohol, and terephthalic acid, an unsaturated dicarboxylic acid without the above-mentioned drawbacks was obtained. Although saturated polyester was produced.

Under normal conditions, the reaction between terephthalic acid and glycol is
It was late in the 4th day, and it turned out that A) was difficult to hire as a second job. To overcome this, (d) (c [5, For example, raising the reaction temperature under pressure has been carried out, but the product is markedly colored.) As a result of the reaction, ether bonds increase in the polyester, resulting in poor storage stability, poor button and φ properties, and hot water resistance.

In this way, when using terephthalic acid, there are 4 reaction methods. - There is a limit to the effect you can get even if you lose it.
N), must be utilized in the form of dimethyl terephthalate. In this case, even if a transesterification reaction catalyst is used, it requires a long time at the product temperature, so there are few examples of production constraints, and there are only a few reports on physical properties. In addition, attempts were made to synthesize unsaturated polyesters using conventional phthalic acid and isophthalic acid, but the reaction temperature was too high.
Because the reaction time is long, the resin can only be obtained in a state that is gelatinous or close to gelatinous during production.

For unsaturated polyesters using not only phthalic acid but also inophthalic acid, a one-step synthesis method in which the reaction raw materials are prepared in -11 is ijJ.
It is Noh. However, in the case of unsaturated polyester using dimethyl prephthalate, even if a transesterification reaction catalyst is used, the reaction progresses in the one-step B process, and unreacted dimethyl terephthalate sublimates and sticks firmly to one molecule. Since the reaction is carried out while blowing inert gas, the fractionator is connected, creating a dangerous situation and making it impossible to proceed with the reaction. Generally, a two-step synthesis method is used to synthesize unsaturated polyesters using isophthalic acid. In the two-stage synthesis method, first, terephthalic acid mebule, a polyhydric alcohol, and a transesterification catalyst are charged.

If you proceed with the reaction by heating, then add maleic anhydride and the remaining polyhydric alcohol, and conduct the reaction by heating, the first reaction must be kept at a high temperature of 200°C or more for a long time, making it inactive. Even if the reaction was carried out while blowing gas and the oxygen was removed, the slight amount of impurities present in the raw materials would cause significant coloring, making it difficult to prepare maleic anhydride and the remaining polyhydric alcohol in the second step. If it is difficult to suppress the reaction later, and the viscosity increases significantly, it will gel during the reaction. This tendency is evident in the case of surface-reactive unsaturated polyesters.Even if the reaction is stopped immediately after the viscosity rises rapidly, the resulting resin has poor storage stability and cannot be used satisfactorily.

The present invention was obtained as a result of studying methods for producing unsaturated polyesters using dimethyl terephthalate, which can effectively exhibit the effects of solvents.

The present invention involves (1) dimethyl terephthalate and a polyhydric alcohol being reacted under a transesterification catalyst;
2) It relates to a method for producing an unsaturated polyester, which involves reacting an unh1p dibasic acid, a polyhydric alcohol, and, if necessary, a saturated dibasic acid using a solvent.

In the present invention, since a solvent is used in the production of Fushowa polyester using dimethyl terephthalate, the esterification reaction can proceed smoothly by lowering the reaction temperature. The resulting unsaturated polyester has fewer ether bonds generated by side reactions, has a lower end group concentration, has a uniform molecular weight distribution, has excellent storage stability, I# component property, 11rt hydrothermal property, and color. is significantly improved.

The solvent used in the present invention is commonly understood as polyhydric alcohol,
Particularly if it is poorly soluble in water, it is particularly difficult to use. For example, benzene, ethylbenzene.

Exclusive to pensene such as chlorbenzene, toluene.

Ky/lene, nochlohequinane, hepta/, mixtures thereof, etc. are used. If the amount of the solvent used in the present invention is too small, the effect will be small, and if it is too large, there is a risk of bumping.
Preferably 0.5 to 10/heavy wound, more preferably 2 to
4. I am in charge of car rental. The boiling point of the solvent used is preferably 80°C to 180°C, more preferably 1000°C to 145°C, because if the boiling point is too low, it will cause bumping or solvent loss, and if it is too high, the effect will be small.

In the present invention, examples of the A/I tribasic acids include maleic acid, maleic anhydride, fumaric acid, itacic acid, citraconic acid, alK water/l laconic acid, or halogen-substituted products thereof. Saturated dibasic acids that may be used and may be used depending on requirements include phthalic acid, fucuric anhydride, isophthalic acid, a/hinic acid, detrahyphthalic acid, tetrahydrocuric anhydride, methyltetrahydrophthalic acid. , methylketrahydrophthalic anhydride, endomethylenedetrahydronotaric anhydride, chlordic acid, and the like.

Examples of polyhydric alcohols include ethylene glycol, propylene glycol, diethylene glycol, and phlohylene glycol.

Neopentyl chloride: 1-l, ■, 3-butanediol,
Impentyl glycol, 1,6-hexaneol,
Trimebulene gellicol, glycerin, p-cyclohegyrindimethanol, and the like are used.

The unsaturated IJ ester obtained by the production method of the present invention is dissolved in a co-monomer to form an unsaturated first polyester resin. .

Chlorosnarene/vinylhensen, vinyl acetate, diallyl phthalate, diallyl isophthalate, etc. are commonly used, and these may be used alone or in combination.

As the Nisder exchange reaction catalyst, lead acetate, lead in acetic acid 11, lead oxide, manganese chloride, alcoholic manganese chloride, etc. can be used. Hydroquino/.

2.5-C Hydroquinone derivatives such as t-butylhydroquinone, polymerization inhibitors such as human lokimeno ethers, bisphenols, resolunols, ultraviolet absorbers,
It is also possible to add low shrinkage agents, defoamers, 9 colorants, etc. after the production of the unsaturated polyester resin.

According to the method of the present invention, in the first stage reaction, 200
The polyesterification reaction proceeds smoothly even when kept at a high temperature of ~210°C for a long time and heated to 1806°C ~ 230°C in the second stage reaction, producing an unsaturated polynisder product with the desired viscosity and acid value of 1 molecule. You can obtain a product with low shelf life, low color, and poor chemical resistance and hot water resistance.

Acid value, viscosity and hue N: JiS, 1 (side layered according to 6901. Storage temperature was measured at 00°C).

Methanol tolerance is a measure of transesterification reaction, and the value is shown at 25°C. The alkali resistance test and boiling resistance test were measured according to JIS K 6919 (boiling time 50 hours).

Example 1 1,160 parts of dimethyl terephthalate and 760 parts of propylene glycol were charged into a 20,001 ng four L1 flask equipped with a thermometer, a stirrer, a nitrogen gas inlet tube, and a divider, and then 0.2 part of lead acetate was added, The temperature was gradually raised in a nitrogen stream while stirring and maintained at 200°C to continue the transesterification reaction.

After about 15 hours, the methanol tolerance of the reactant reached 28, so heating was stopped and the mixture was cooled to 100°C. To this, 392 parts of maleic anhydride, 125 parts of neopentyl glycol and 70 parts of quinoles were charged.
The second reaction was started by heating to ℃. The progress of the reaction was measured using the acid value and Cartner viscosity gt, and the result was approximately 16
After 1 hour of reactant acid 9. When the viscosity of a 40% styrene solution is 6 hours, recover xylene and
Heating was discontinued when the viscosity of the solution was 12 poise, and the solution was cooled to reach the end point of the reaction. This reaction product (non-conductive polyester) styrene l 4 b 7 parts + hydroquinone 0
．． 24 parts of 10% copper naphthenate was dissolved in 1467 parts of styrene to which 017 parts of 10% copper naphthenate was added to obtain a pale yellow transparent unsaturated polyester resin (Resin A). The properties of this resin are shown in Table 1. For comparison, 4 hours without using the bath agent Ki/Ren.
J resin was produced (resin A').

As shown in Table 1, this resin A' has an extremely short product life and extremely poor chemical resistance and hot water resistance.

There was no value in using it at all.

Example 2 776 parts of dimethyl prephthalate, 60 parts of propylene glycol, and 0.25 parts of l'l'l lead were warped for 20 minutes in the same manner as in Example 1, and after about 17 hours, methanol traces were reduced to 2.3 II. (-Natsu/At this point, the reaction was completely stopped, and 588 parts of maleic anhydride and 3 parts of diethylene glycol were added.
Add 18 parts and 60 parts of quince to the reaction vessel.

The reaction was completed under the same conditions as in Example 1. 4 after about 22 hours
Since the viscosity of the 0-coefficient snalene solution reached 15%, heating was stopped and the solution was cooled to +N to reach the end point of the reaction. This reaction product was converted into 0.251W of hydroquinone.

Styrene 1 added with 19 parts of 10% Nanthenic Acid Button U
, to obtain 550 parts of a light-colored, transparent, slightly saturated polyester resin ((Kaji B). The properties of this resin are shown in Table 1. When a similar experiment was conducted, the viscosity increased rapidly from about 14:00 hours after the start of the second stage reaction, resulting in gelation.

Example 3 776 parts of dimethyl terephthalate, 304 parts of propylene glycol, and 416 parts of iopentyl glycol were mixed in the presence of 0.2 part of lead acetate as a transesterification catalyst to yield 111 Examples 1
It reacted in the same way. After about 18 hours, the methanol toleranos reached 25, so the reaction was stopped, and 588 parts of maleic anhydride and 6 parts of Ethylene/Crystalline 1B were reacted and charged into a container.

A second reaction was carried out by heating at 220°C.

After 30 minutes of keeping the temperature at 220°C, 68 parts of toluene was added and the toluene was circulated to allow smooth distillation of condensed water, resulting in an acid value of 8.
When the viscosity of the Sunare Y 40% m solution reached 7 bores, the Tonojoene was collected and the reaction proceeded about 3 times. This reaction product was dissolved in 1,444 parts of styrene to which 0.23 parts of itoquinone and 0.17 parts of 10% naphthi/copper acid were added to obtain a pale lilac-colored transparent saturated polyester resin (resin C).
. The properties of this resin are shown in Table 1.

For comparison, an experiment similar to Example 2 was conducted without using toluene as a solvent (resin C'). This resin C' is shown in Table 1.
As shown in Figure 2, the product life was short, and the chemical resistance and hot water resistance were poor, and the product had no commercial value.

+1 (1% hydroxide) IJ Uno, after boiling in an aqueous solution for 50 hours, the appearance C■ is abnormal [7 △ indicates deterioration of gloss × indicates occurrence of cracks *4 1.00℃, Crank generation time of casting board in tap water The unsaturated polyester resin obtained using the unsaturated polyester obtained by the production method of the present invention has extremely excellent storage stability compared to conventional unsaturated polyester resin. , and because there are few side reactions, the chemical resistance and hot water resistance are questionable.

＼゛、Main

Claims (1)

[Claims] 1.) Methyl terephthalate and a polyhydric alcohol are reacted under a transesterification catalyst. 1. Next, (2) an unsaturated dibasic acid and a polyhydric alcohol, and if necessary, a saturated dibasic acid is further dissolved. A process for producing unsaturated polyesters, which is characterized by reacting with esters.