JP3396301B2 - Method for producing unsaturated polyester resin - Google Patents

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 useful in the fields of FRP, paints and casting, and which can be carried out at a relatively low cost.

[0002]

BACKGROUND OF THE INVENTION In general, unsaturated polyester resins are prepared by esterifying an α, β-unsaturated polybasic acid or its anhydride, and optionally other saturated or unsaturated polybasic acid with glycols. It is obtained by dissolving an unsaturated polyester obtained by the chemical reaction in a copolymerizable polymerizable monomer (monomer) (in the present specification, in order to avoid confusion, a type to which a monomer is added is not used). Saturated polyester resin and unsaturated alkyd without monomer is called unsaturated polyester to distinguish).

Conventionally, styrene has been typically used as a monomer, and an unsaturated polyester having compatibility therewith is unavoidable even if its composition is limited to some extent. For example, unsaturated polyesters containing only ethylene glycol and / or diethylene glycol as a glycol component generally have poor compatibility with styrene, and these are not completely dissolved in styrene, and a phenomenon occurs in which styrene is separated. In particular, this separation phenomenon is often observed when phthalic anhydride or isophthalic acid, which is a commonly used modifying saturated acid, is used in combination with an unsaturated polyester resin.

When propylene glycol is used as the glycol component, compatibility with styrene does not have to be a problem, but if half of propylene glycol is replaced with ethylene glycol, the type of saturated acid used for modification is also changed. However, the amount of styrene that forms a uniform solution becomes limited. The use of ethylene glycol is advantageous from the viewpoint of cost, but the physical properties of the cured resin are also poor at the use amount level that causes a limit in compatibility with styrene.

On the other hand, the unsaturated polyester resin using 1,2-butanediol as the glycol component has a bulky substituent such as an ethyl group in the side chain, which may be the reason why the liquid unsaturated polyester resin is cured. The sex is not good. Further, the physical properties (mechanical strength, heat distortion temperature) and the like of the cured resin were inferior to those of the unsaturated polyester resin using propylene glycol.

The present invention is excellent in compatibility with monomers such as styrene and various physical properties while using both components of ethylene glycol and / or diethylene glycol and 1,2-butanediol, and can be carried out at low cost. It is an object of the present invention to provide a method for producing an unsaturated polyester resin that can be used.

[0007]

Means for Solving the Problems The present inventors have conducted a study on a method for correcting the defects of resins using ethylene glycol, diethylene glycol and 1,2-butanediol, and as a result, surprisingly, 1,2- It was found that the use of butanediol and ethylene glycol and / or diethylene glycol in combination eliminates the disadvantages of both, and the present invention was completed.

That is, the present invention relates to [A] the glycol component used, (i) 1,2-
Butanediol 5 to 70 mol%, and (ii) ethylene glycol and / or diethylene glycol 30 to
A glycol component containing 95 mol% as an essential component,
(Iii) An α, β-unsaturated polybasic acid or an anhydride component thereof is esterified to obtain an unsaturated polyester, and then [B] the unsaturated polyester is dissolved in a polymerizable monomer. The present invention provides a method for producing an unsaturated polyester resin.

The present invention will be described in more detail below. (Glycol component) In the present invention, 1,2-butanediol and ethylene glycol and / or diethylene glycol are used as essential components of the glycol component. The amount of 1,2-butanediol compounded is 5 to 70 mol%, preferably 10 to 50 mol%, based on the glycol component used. If it is less than 5 mol%, the effect of the combined use is rapidly reduced and the compatibility with the monomer is impaired. If it is used in excess of 70 mol%, various physical properties are adversely affected. Ethylene glycol and diethylene glycol can be used alone or in combination. The blending amount is based on the glycol component used.
It is 30 to 95 mol%, preferably 50 to 90 mol%. If it is less than 30 mol%, the curability tends to deteriorate, which is not preferable. If it is used in excess of 95 mol%, the monomer such as styrene may be separated. It should be noted that the use of other glycols other than the above essential glycol components is not hindered if necessary.

(Α, β-Unsaturated Polybasic Acid or Anhydride Component Thereof) The α, β-unsaturated polybasic acid or its anhydride component usable in the present invention is not particularly limited, but for example, maleic anhydride, Examples include fumaric acid, itaconic acid, citraconic acid and the like. Generally, maleic anhydride or fumaric acid is used.

(Saturated or unsaturated polybasic acid or anhydride component thereof) In the present invention, a saturated or unsaturated polybasic acid or anhydride component thereof may be used, if necessary. Examples thereof include phthalic anhydride, isophthalic acid, dimethyl terephthalic acid, adipic acid, tetrahydrophthalic anhydride, and het anhydride. The saturated or unsaturated polybasic acid or its anhydride component is used for improving and changing various physical properties of the unsaturated polyester resin. For example, isophthalic acid improves heat resistance and adipic acid imparts toughness. be able to.

(Proportion of Use of Two or Three Components) The use ratio of the glycol component, the α, β-unsaturated polybasic acid or its anhydride component and the saturated or unsaturated polybasic acid or its anhydride component is particularly limited. It is not decided, but decided appropriately.

(Esterification reaction) The esterification reaction of the above-mentioned two or three components can be carried out by a conventional method. For example, while flowing nitrogen, 160 ~ 230 ℃
It can be esterified to an acid value of 40 or less, preferably 15 or less, more preferably 10 or less.
Further, as esterification catalysts, organic compounds of titanium such as tetraisopropyl titanate and acetylacetonate of titanium; organic salts of zinc such as zinc acetate; tin compounds such as dibutyltin oxide; inorganic compounds of antimony such as antimony trioxide. Can be used. The amount used is 0.1 parts by weight or less based on the charged amount of the above-mentioned two or three components.

(Unsaturated Polyester Resin) Subsequently, the unsaturated polyester resin obtained as described above is dissolved in a monomer to prepare an unsaturated polyester resin. Typical examples of the monomer that can be used include styrene, but vinyltoluene, methyl methacrylate, diallyl phthalate, diallyl terephthalate and the like can be used. At this time, a desired polymerization inhibitor may be used together. The amount of the monomer used is 20 to 60% by weight, preferably 25 to 5 in the unsaturated polyester resin.
0 wt% is suitable.

The unsaturated polyester resin obtained as described above can be cured in the same manner as the conventional type. Further, it is needless to say that an inorganic or organic reinforcing material, a filler, a coloring agent, a release agent, a wax, a polymer or the like can be used in combination for practical use thereof.

[0016]

EXAMPLES The present invention will be described below with reference to examples. Reference example In a 1 liter separable flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas introduction tube, propylene glycol and ethylene glycol as glycol components,
Maleic anhydride was used as the α, β-unsaturated polybasic acid component, and phthalic anhydride was used as the other saturated or unsaturated polybasic acid component at the blending ratios shown in Table 1, respectively.
An esterification reaction was carried out in a nitrogen gas stream at 185 to 200 ° C. for 10 hours to obtain the acid value shown in Table 1, and then 0.02 phr of hydroquinone was added and dissolved in styrene to obtain an unsaturated polyester having a styrene content of 40%. A resin was produced.

Examples 1 to 3 An unsaturated polyester resin was produced by repeating the reference example except that 1,2-butanediol and ethylene glycol were used in the mixing ratios shown in Table 1 as the glycol components.

Comparative Example 1 An unsaturated polyester resin was produced by repeating the reference example except that the mixing ratio of propylene glycol and ethylene glycol was changed as shown in Table 1.

Comparative Example 2 An unsaturated polyester resin was produced by repeating the reference example except that the mixing ratio of propylene glycol and ethylene glycol was changed as shown in Table 1.

Each of the unsaturated polyester resins produced in the above Reference Examples, Examples and Comparative Examples was left to stand overnight and the compatibility between the unsaturated polyester and styrene was examined. The results are shown in Table 1.

[0021]

[Table 1]

From the results in Table 1: In the reference examples, propylene glycol is used in a large amount, so that the compatibility with styrene is good; Examples 1 to 3 include 1,2-butanediol and ethylene glycol. Good compatibility with styrene due to the combined use; however, Comparative Example 1
In ~ 2, due to the large amount of ethylene glycol used,
It can be seen that even if propylene glycol is blended, the compatibility with styrene is deteriorated.

Example 4 A 1-liter separable flask equipped with a stirrer, a fractionating condenser, a thermometer, a gas introduction tube, and a gas flow meter was used to obtain 8.4 mol of ethylene glycol and 1,2-butanediol.2.
1 mol, 5 mol of maleic anhydride and 5 mol of phthalic anhydride were charged and subjected to esterification reaction in a nitrogen gas stream at 185 to 200 ° C. for a predetermined time to give a predetermined acid value, and then hydroquinone 0.02 phr at 120 ° C. In addition, it was dissolved in styrene to produce an unsaturated polyester resin having a styrene content of 35%. The reaction conditions and physical properties of the resulting unsaturated polyester are summarized in Table 2.

Comparative Example 3 Example 4 was repeated except that 10.5 mol of 1,2-butanediol alone was used as the glycol component.
An unsaturated polyester resin was produced.

Comparative Example 4 Propylene glycol alone was used as the glycol component 1
An unsaturated polyester resin was produced by repeating Example 4 except that 0.5 mol was used.

[0026]

[Table 2]

To 100 parts by weight of each unsaturated polyester resin obtained in Example 4 and Comparative Examples 3 to 4, 1 part by weight of methyl ethyl ketone peroxide (MEKPO) and 0.5 part by weight of cobalt naphthenate (Np-Co) were added. In addition, it was put into a casting mold, gelled, and post-cured at 105 ° C. for 1 hour. The physical properties of the resulting cured cast plate are summarized in Table 3. The size and shape of the casting plate conformed to the following test standards.

[0028]

[Table 3]

Example 5 In a 1-liter separable flask equipped with a stirrer, a reflux condenser, a thermometer, and a gas inlet tube, 5 mol of ethylene glycol, 4 mol of diethylene glycol, 1 mol of 1,2-butanediol, and methyltetrahydrophthalic anhydride. Acid 3
Mol and fumaric acid 7 mol were charged, and in a nitrogen gas stream,
After esterification reaction at 200 to 205 ° C for 10 hours to make the acid value 28.9, hydroquinone 0.02 phr was added, and after cooling to 140 ° C, the amount of styrene in the unsaturated polyester resin was 30, 40 and 50%. Styrene was added so that The compatibility of each unsaturated polyester with styrene was investigated. The results are shown in Table 4.

Comparative Example 5 Example 5 was repeated except that only 5 moles of ethylene glycol and 5 moles of diethylene glycol were used as the glycol component and the acid value after esterification was set to 31.7.

[0031]

[Table 4]

From Table 4, it is recognized that the unsaturated polyester resin obtained by the present invention has excellent compatibility with styrene even when the unsaturated polyester concentration is 50%. However, the unsaturated polyester resin obtained by using only ethylene glycol and diethylene glycol as a glycol component has poor compatibility with styrene at an unsaturated polyester concentration of 60%.

[0033]

According to the present invention, compatibility with monomers such as styrene and various physical properties are excellent, and ethylene glycol and diethylene glycol can be mainly used.
Provided is a method for producing an unsaturated polyester resin which can be carried out at low cost.

Claims (3)

(57) [Claims] 1. [A] With respect to the glycol component used,
(I) 5-70 mol% of 1,2-butanediol, and (ii) a glycol component containing 30 to 95 mol% of ethylene glycol and / or diethylene glycol as essential components, and (iii) α, β-unsaturated polybasic A process for producing an unsaturated polyester resin, which comprises esterifying an acid or an anhydride component thereof to obtain an unsaturated polyester, and then [B] dissolving the unsaturated polyester in a polymerizable monomer. 2. The production method according to claim 1, wherein the amount of 1,2-butanediol compounded is 10 to 50 mol% based on the glycol component used. 3. The production method according to claim 1, wherein the blending amount of ethylene glycol and / or diethylene glycol is 50 to 90 mol% with respect to the glycol component used.