JPH0822909B2 - 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SUMMARY OF THE INVENTION The present inventors have proposed, as a previously untried, at least unpublished method, the deglycolization found in the production of unsaturated polyesters and in the production of polyethylene terephthalate.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, (ii) a reduced pressure of 5 mmHg or less, preferably 1 mmHg or less, and (iii) tetraalkyl as a catalyst for the deglycolization reaction. A titanium compound is used. The present invention relates to a catalyst for a deglycolization reaction which replaces the above tetraalkyl titanium. That is, the present invention provides a polycarboxylic acid having or without modifying an α, β-unsaturated polybasic acid (or an acid anhydride thereof) with or without any saturated or unsaturated polybasic acid (or an acid anhydride thereof). In a method for producing an unsaturated polyester by esterifying with an alcohol and then performing a deglycol reaction, 0.01 to 3 parts by weight of zinc, cadmium, and
An organic acid salt or alkoxy compound of at least one metal selected from the group consisting of lead, zirconium, cobalt, manganese, and tin, and phosphorous acid are added at the stage of the esterification or deglycolization reaction. The present invention provides a method for producing an unsaturated polyester.

The present invention will be described in more detail below.
The reason for using the organic acid salt or alkoxy compound of the metal and phosphorous acid in the present invention is to increase the number average molecular weight of the unsaturated polyester to be produced, while suppressing the increase of the weight average molecular weight as much as possible, and to prevent the synthesis reaction from gelling. It is to do it safely without making it change. Further, in the synthesis of unsaturated polyester, in the deglycolization reaction following the esterification, the number average molecular weight does not change significantly from the stage where it reached an almost constant value, while the weight average molecular weight is the reaction time. Along with that, gelation is finally reached. This is a point that is fundamentally different from the thermoplastic polyester (saturated polyester), and is the reason that the conditions for producing unsaturated polyester cannot be known from the knowledge of saturated polyester synthesis. In the present invention, the above-mentioned organic acid salts or alkoxy compounds of various metals, and phosphorous acid enable the synthesis of high molecular weight polyester having a number average molecular weight of 5000 or more, and further, the weight average molecular weight of 10 or more.
The tendency to increase from 10,000 to 200,000 is 5
It is based on the finding that it can be reduced to 10,000 to 150,000. As the organic acid salt of the metal that can be used in the present invention, various organic acid salts can be used, and examples thereof include acetate, naphthenate, octylate, and oxalate. Specific examples include zinc acetate, cadmium acetate, lead acetate, zirconium octylate, cobalt acetate, manganese acetate, stannous oxalate, dibutyltin oxide, triisopropyl zirconate, tributyl zirconate, and lead octylate. In addition to the above organic acid salts, alkoxy compounds of the above metals can also be used.
The amount of the organic acid salt of the metal or the alkoxy compound used is 0.
It is 0.01 to 3 parts by weight, preferably 0.05 to 1 part by weight. Further, in the present invention, phosphorous acid is used in combination with the organic acid salt or alkoxy compound of the above metal. Phosphorous acid is considered to act as a stabilizer during the deglycolization reaction. The amount of phosphorous acid used is 0.01 to 1 part by weight, based on 100 parts by weight of the unsaturated polyester produced.
It is preferably 0.02 to 0.2 part by weight. In addition to phosphorous acid, some inorganic and organic phosphorus compounds such as phosphoric acid, phosphoric anhydride, alkyl acid phosphate, and triphenyl phosphite have similar effects. In order to obtain the same effect, it is necessary to use a large amount, which has the drawback that the curability of the polyester resin is significantly impaired.

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 essential, and any saturated or unsaturated polybasic acid (or its acid anhydride) can be used in combination. Then, it is common practice to provide resin with various physical 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 the organic acid salt or alkoxy compound of the metal may be added from the beginning of the esterification. It may be the start time of the glycol reaction. The addition of phosphorous acid may be at the beginning of esterification or at the start of the deglycolization reaction.
In addition, an organic acid salt or an alkoxy compound of the metal,
It is not essential to add phosphorous acid at the same time, and phosphorous acid may be added at different stages. 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 give an acid value of 26.9, 5.8 kg of fumaric acid was added, and the esterification temperature was adjusted to 190 to 205 ° C.
At the end of the reaction, a pressure reduction of 10 to 12 mmHg was carried out for about 2 hours to give a final acid value of 7.9, 4 g of hydroquinone was added, and the mixture was discharged into a metal vat and solidified. Softening point about 75 ℃, molecular weight 2
200 light tan unsaturated polyesters (I) were obtained.

Example 1 High molecular weight unsaturated polyester (A) 500 g of the unsaturated polyester (I) obtained above was placed in a 1 liter separable flask equipped with a stirrer, a distilling condenser, a thermometer and a gas inlet tube. Charge 1.5 g of zinc acetate and 0.25 g of phosphorous acid, start reducing pressure at a temperature of 200 to 205 ° C., and reduce from 5 mmHg to 0.5 mmHg over 6 hours.
Deglycolization reaction was carried out by stirring under reduced pressure at 0.7 to 0.5 mmHg for about 3 hours and 30 minutes. The resulting unsaturated polyester (A) had a final number average molecular weight of 7,500 and a weight average molecular weight of about 80,000.

Example 2 High molecular weight unsaturated polyester (B) A high molecular weight unsaturated polyester (B) was prepared in the same manner as in Example 1 except that the pressure was reduced to 0.7 to 0.5 mmHg for about 2 hours without adding phosphorous acid. An unsaturated polyester (B) was synthesized. The resulting unsaturated polyester (B) had a final number average molecular weight of 5,900 and a weight average molecular weight of 174,000. The transition of the relationship between the number average molecular weight and the weight average molecular weight of each of the unsaturated polyesters (A) and (B) is shown in FIG. 1, and the unsaturated polyester (A) to which phosphorous acid has been added In contrast to the linear relationship between the number average molecular weight and the weight average molecular weight, the unsaturated polyester (B) that does not use phosphorous acid increases the number average molecular weight and the weight average molecular weight exponentially increases. You can see that

Examples 3 to 14 Into a 1 liter separable flask equipped with a stirrer, a distilling condenser, a thermometer, and a gas introduction tube, 500 g of unsaturated polyester (I) was charged, and Table 1 shows each example. An unsaturated polyester was produced in the same manner as in Example 1 except that the compounds shown below were added.

[0010]

[Table 1]

The results are summarized in Table 2. It is recognized that the system to which phosphorous acid is added has a small increase in the weight average molecular weight as compared with the number average molecular weight.

[0012]

[Table 2]

[0013]

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.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the number average molecular weight and the weight average molecular weight of phosphors with and without addition of phosphorous acid.

Claims (1)

[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 3 parts by weight of zinc, cadmium, lead, zirconium and cobalt are added to 100 parts by weight of the produced unsaturated polyester. ,
An unsaturated polyester, characterized in that an organic acid salt or alkoxy compound of at least one metal selected from the group consisting of manganese and tin, and phosphorous acid are added at the stage of the esterification or deglycolization reaction. Production method.