JP2527504B2 - Method for producing unsaturated polyester - 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 a high molecular weight unsaturated polyester having a molecular weight (number average molecular weight, the same applies hereinafter) of 5000 or more.

[0002]

2. Description of the Related Art Polyester resin (unsaturated polyester dissolved in a copolymerizable monomer is referred to as below) is used as a general-purpose FRP matrix resin in baths, septic tanks, vanities, etc. Residential equipment, fishing boats, leisure-related equipment and facilities, such as boats, yachts and other boats, as well as corrosion-resistant equipment, automobile parts, etc. It is also used for cast relations. For example, polyester resin is mixed with filler, glass fiber, curing agent, thickener and aged, and then sheet molding compound Sheet Molding Compaund (SM
C), it is used for housing equipment such as bathtubs, or outer panels of automobiles. However, as the applications are expanded, the physical properties of the resin are required to be higher, and it is necessary to further improve the boiling resistance, the strength, the elasticity, etc., for example. In order to meet such requirements, various methods for improving resins have been tried, but one of them is to increase the molecular weight. That is, by increasing the molecular weight of the unsaturated polyester that constitutes the polyester resin, the heat distortion temperature and the strength tend to increase. However, the current molecular weight of unsaturated polyester is 2000-2.
It is a so-called prepolymer of about 500, and as long as it depends on the esterification method, it is extremely difficult to further increase the molecular weight from the viewpoint of gelation risk. That is, in the deglycolization reaction following the esterification, the number average molecular weight does not change much from the stage where it reached a substantially constant value, while the weight average molecular weight continues to increase with the reaction time and finally gels. To reach.
This point is fundamentally different from the thermoplastic polyester (saturated polyester).

[0003]

SUMMARY OF THE INVENTION The present inventors have proposed, as a previously untried, at least unpublished method, the deglycolization found in the production of unsaturated polyesters and in the production of polyethylene terephthalate. A molecular weight of 5 is applied if the reaction is applied and the following conditions are met:
It was clarified that a high molecular weight polyester of 000 or more can be synthesized (Japanese Patent Application No. 1-292354). That is, (i)
The acid value after esterification is 15 or less, preferably 10 or less, and (ii) a reduced pressure of 5 mmHg or less, preferably 1 mmHg or less, (iii) using a tetraalkyl titanium compound as a catalyst for the deglycolization reaction. . The present invention relates to a catalyst for a deglycolization reaction which replaces the above tetraalkyl titanium. That is, the present invention
α, β-unsaturated polybasic acid (or its acid anhydride), any saturated or unsaturated polybasic acid (or its acid anhydride)
In a method for producing an unsaturated polyester by esterifying with a polyhydric alcohol and then performing a deglycolization reaction with or without modification with 0.01 to 5 parts by weight based on 100 parts by weight of the resulting unsaturated polyester. ,Titanium,
An acetylacetonate type chelate compound of at least one metal selected from the group consisting of cobalt, zirconium, zinc, manganese, iron and vanadium is added at the stage of the esterification or deglycolization reaction. A method for producing a saturated polyester is provided.

The present invention will be described in more detail below.
The reason for using the metal acetylacetonate type chelate compound in the present invention is to increase the number average molecular weight of the unsaturated polyester to be produced, to suppress the increase of the weight average molecular weight as much as possible, without gelling the synthetic reaction,
To do it safely. In the present invention, the metal acetylacetonate type chelate compound described above effectively acts to increase the number average molecular weight, but has less tendency to increase the weight average molecular weight as compared with the case of using a general organometallic compound. It is based on the point of finding. The amount of these chelate compounds used is 0.01 to 5 parts by weight, preferably 0.05 to 1 part by weight, based on 100 parts by weight of the unsaturated polyester produced.

The raw material of the unsaturated polyester used in the present invention is not particularly limited, but has a molecular weight of 50.
In order to make it more than 00, 5 of the polyhydric alcohol used
It is preferable that the boiling point (760 mmHg) of 300 ° C. or less is 0 mol (%) or more. Use of α, β-unsaturated polybasic acid represented by fumaric acid or maleic anhydride or its acid anhydride is indispensable, and any saturated or unsaturated polybasic acid or its acid anhydride should be used in combination. Generally, it is common practice to give various resin properties. In the synthesis of the unsaturated polyester according to the present invention, general esterification is followed by a deglycolization reaction, but the addition of a metal acetylacetonate type chelate compound may be added from the beginning of the esterification. It may be the start time of the glycol reaction. Also, it is advantageous to add a polymerization inhibitor in order to prevent gelation during the reaction. The unsaturated polyester according to the present invention is dissolved in a copolymerizable monomer and used as a polyester resin for various purposes. At that time, if necessary, a reinforcing material, a filler, a colorant, a release agent, and a thickening agent. Of course, an agent, a thermoplastic polymer, a curing agent and the like can be used in combination.

Next, in order to help understanding of the present invention, examples will be shown below. (Example of esterification reaction) In a 30-liter stainless steel reaction vessel equipped with a stirrer, a fractionating condenser, a thermometer, and a gas introduction tube, 8.8 kg of propylene glycol and 8.3 isophthalic acid.
After charging kg, esterification in a nitrogen gas stream at 180 to 190 ° C to an acid value of 21.9, 5.8 kg of fumaric acid was added, and the esterification temperature was further set to 190 to 205 ° C and the pressure was reduced to 10 to 12 mmHg at the end of the reaction. Was carried out for about 2 hours to give a final acid value of 8.9, 4 g of hydroquinone was added, and the mixture was allowed to flow into a metal vat and solidified. A pale tan unsaturated polyester (A) having a softening point of about 70 to 75 ° C. and a molecular weight of 2040 was obtained.

Examples 1 to 17 Into a 1 liter separable flask equipped with a stirrer, a condensing condenser ( reducible pressure type), a thermometer, and a gas introduction tube, 500 of each unsaturated polyester (A) produced in the reaction example
g, each of the reaction catalysts summarized in Table 1 was 1.5 g (0.
3 phr), and the deglycolization reaction was finally carried out for a total of 6 hours (after reaching the reaction temperature) under a reduced pressure of 0.7 to 0.8 mmHg for about 2 hours at a temperature of 195 to 200 ° C.
Differences depending on the type of deglycolization reaction catalyst are shown in Examples 1 to 1.
17 is summarized in Table 1. As can be seen from these results, the example using the metal acetylthitonate chelate compound of the present invention was used in a general deglycolization reaction although the weight average molecular weight did not increase so much compared to the number average molecular weight. It is apparent that the use of the above-mentioned types of organic metal salts markedly increases the weight average molecular weight and lacks stability in the reaction.

[0008]

[Table 1]

[0009]

EFFECTS OF THE INVENTION Since the present invention is constructed as described above, the deglycolization reaction can proceed without causing gelation, and it is possible to produce a high molecular weight unsaturated polyester which has not been obtained in the past. Provide high-performance polyester resin that can be applied to a wide range of fields such as automobiles and housing equipment.

Claims (1)

(57) [Claims] 1. An α, β-unsaturated polybasic acid (or its acid anhydride) is modified with or without any saturated or unsaturated polybasic acid (or its acid anhydride) to give a polyvalent polyhydric acid. In a method for producing an unsaturated polyester by esterifying with an alcohol and then performing a deglycol reaction, 0.01 to 5 parts by weight of titanium, cobalt, zirconium, zinc and manganese are added to 100 parts by weight of the resulting unsaturated polyester. A method for producing an unsaturated polyester, characterized in that an acetylacetonate type chelate compound of at least one metal selected from the group consisting of, iron and vanadium is added at the stage of the esterification or deglycolization reaction.