JPH0570577A - Production of aliphatic polyester having urethane bonds - Google Patents

Abstract

PURPOSE:To produce the title polyester having a high m.p. and strengths sufficient for practical use with an extremely small amt. of a catalyst. CONSTITUTION:100 pts.wt. substantially hydroxyl-terminated, aliph. polyester having a number-average mol.wt. of 5,000 or higher is produced by using 0.0001-0.01 pt.wt. org. alkoxytitanium compd. as a catalyst in the process wherein 1,4-butanediol is esterified with a dicarboxyic acid component consisting of 50-100mol% succinic acid and 50-0mol% dicarboxylic acid selected from the group consisting of adipic, sebacic, and lauric acids followed by the elimination of the glycol molecules. Then, 100 pts.wt. the aliph. polyester is reacted with 0.1-5 pts.wt. diisocyanate to give the title polyester.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a practically sufficient strength, a high melting point, a very small amount of catalyst, a film-forming property and a safe handling urethane. The present invention relates to a method for producing an aliphatic polyester containing a bond.

[0002]

BACKGROUND OF THE INVENTION Aliphatic saturated polyesters have a low melting point, and even if they have a number average molecular weight of 10,000 or more in a high molecular weight region, polyesters containing a saturated aromatic structure, such as polyethylene terephthalate, are practically sufficient. Until now, it has been considered impractical because it does not exhibit such mechanical properties. In fact, even if it had film-forming properties, the produced film was weak in tear strength and tensile strength and was not practical. Among these,
Aliphatic polyesters having 1,4-butanediol as a glycol component are relatively strong, but if they are esterified with aliphatic dicarboxylic acids such as adipic acid, sebacic acid, and dodecanoic acid, they do not have sufficient strength, It has been found that a film formable polyester can be produced.
Particularly, in the case of an aliphatic polyester produced by using succinic acid as a dibasic acid, the melting point is as high as 110 to 115 ° C., and most of the aliphatic polyesters show only a melting point of 70 ° C. or less. , Specific. However, the aliphatic polyester produced using 1,4-butanediol and succinic acid is crystalline and is a little fragile even if the number average molecular weight is 10,000 to 15,000 by performing usual esterification and deglycolization reaction. There is a tendency. This brittleness can be improved by using other dicarboxylic acids such as adipic acid, sebacic acid, dodecanoic acid, etc. in combination, but as the number of methylene bonds between carboxyl groups increases, flexibility tends to increase, The melting point will drop. Conventionally, number average molecular weight 10,000
In order to produce the above high-molecular-weight polyester, for example, in the case of polyethylene terephthalate, 0.001 to 0.1 mol of antimony, zinc, titanium, lead, manganese, germanium, zirconium, or another heavy metal organic or inorganic is used per mol of terephthalic acid. The compound has been used to catalyze a deglycolization reaction. It is also known to use a lithium compound in combination. When the amount of the catalyst is generally converted to 100 parts by weight of polyethylene terephthalate,
It is 0.1 to 1 part by weight, and it has been considered difficult to obtain a high molecular weight polyester with a catalyst amount less than this. However, from the viewpoint of safety, it is desirable to use the catalyst in a small amount as much as possible when it is practically handled or discharged as dust. The present invention solves the above-mentioned conventional problems, has an aliphatic polyester having a practically sufficient strength and a high melting point, and further has a film-forming property in which a very small amount of a catalyst can be used. It is an object of the present invention to provide a manufacturing method of.

[0003]

As a result of earnest studies, the present inventors were able to solve the above problems. That is, the present invention comprises 1,4-butanediol and 50-100
Obtained by esterification with mol% succinic acid and 50-0 mol (%) at least one dicarboxylic acid selected from adipic acid, sebacic acid and dodecanoic acid, and subjecting the resulting esterified product to a deglycol reaction. When producing a saturated polyester (I) having a number average molecular weight of 5,000 or more and an end group substantially a hydroxyl group, 100 parts by weight of the saturated polyester (I),
Using 0.0001 parts by weight to 0.01 parts by weight of an organic alkoxytitanium compound as a catalyst, 0.1 part by weight to 5 parts by weight of a diisocyanate is reacted with 100 parts by weight of the obtained saturated polyester (I), Finally number average molecular weight
The present invention provides a method for producing an aliphatic polyester containing a urethane bond, characterized in that the amount is 10,000 or more.

The present invention will be described in more detail below.
Unless otherwise specified, the number average molecular weight is simply referred to as the molecular weight. The present inventors have found that 1,4-butanediol and succinic acid,
And, if necessary, in combination with adipic acid, sebacic acid or dodecanoic acid, when synthesizing a saturated polyester having a molecular weight of 10,000 or more, as a result of studying an effective catalyst in a small amount, only one type of titanium-based catalyst, It was found that even a small amount of 0.01 parts by weight or less based on 100 parts by weight of the produced polyester is effective, and further it was found that it is effective to react the obtained saturated polyester with diisocyanate, and the present invention was completed. We were able to. The production of a saturated polyester composed of 1,4-butanediol and succinic acid, and optionally adipic acid, sebacic acid or dodecanoic acid can be carried out by a known technique. The esterification reaction and deglycolization reaction conditions for producing this saturated polyester can be set to appropriate conditions conventionally used, and are not particularly limited. The amount of 1,4-butanediol used is substantially equimolar to 100 mol% of succinic acid or a mixed acid of succinic acid and at least one dicarboxylic acid selected from adipic acid, sebacic acid and dodecanoic acid. But
Generally, since there is distillate during esterification, it is used in excess of 5 to 20 mol%. As the acid used in combination with 1,4-butanediol, only succinic acid can be used. Apart from this, a suitable mixing ratio of each component in succinic acid and at least one dicarboxylic acid-based mixed acid selected from adipic acid, sebacic acid and dodecanoic acid is usually 50 mol% or more for succinic acid. The amount of dicarboxylic acid such as adipic acid is preferably 50 mol% or less, more preferably 40 mol% or less. When the amount of the dicarboxylic acid used in combination with succinic acid exceeds 50 mol%, the melting point of the obtained saturated polyester becomes 70 ° C. or lower, which is not preferable in practice.

The catalyst preferably used in the present invention is an organic alkoxytitanium compound represented by the general formula Ti (OR) ₄ (wherein R represents an alkyl group), and examples thereof include tetraethoxytitanium and tetraisoproxy. Examples thereof include titanium and tetrabutoxytitanium. The amount of this catalyst used is 1,4-
0.0001 to 0.01 part by weight, preferably 0.001 part to 0.01 part by weight, relative to 100 parts by weight of a saturated polyester consisting of butanediol and succinic acid, and optionally adipic acid, sebacic acid or dodecanoic acid. Good. If the amount used is less than 0.0001 parts by weight, the action of the catalyst becomes weak,
It becomes difficult to obtain the target molecular weight. Also, 0.
Even if it is used in an amount of more than 01 parts by weight, its action does not change significantly. The obtained aliphatic polyester is preferably cooled and solidified in the shortest possible time. The molecular weight of the saturated polyester obtained as described above was 5,
It is necessary to be 000 or more. Molecular weight is 5,000
If it is less than 0, the amount of diisocyanate added increases, and the risk of gelation increases rapidly.

Next, the addition of diisocyanate will be described. The diisocyanate used in the present invention is not particularly limited, and commercially available products can be used as they are, but in order to prevent coloration of the reaction product obtained by adding this, an aliphatic diisocyanate such as hexamethylene is used. It is desirable to select diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate. The ratio of its use is 0.1 to 100 parts by weight of a saturated polyester composed of 1,4-butanediol and succinic acid prepared as described above, and optionally adipic acid, sebacic acid or dodecanoic acid. 5 parts by weight, preferably 0.5-2 parts by weight. The addition of diisocyanate is not less than the melting point of the saturated polyester, that is, it can be sufficiently stirred and mixed.
It is preferable to carry out at 50 ° C. or higher.

It is well known that a polyester having a hydroxyl group at the end is reacted with diisocyanate to prepare a polyurethane resin, such as a paint, an adhesive, a molded article or a foam, which has been widely put into practical use. The differences between these existing polyurethane resins and the present invention are summarized as follows. (A) The saturated polyester used in the present invention is required to be crystalline from the viewpoint of the strength development of the film, etc., but in general, polyurethane resin, paints and adhesives dissolved in a solvent, rubber, foam molding The saturated polyester must be amorphous in order to be used in commercial products. (B) The hydroxyl polyester used for producing the existing urethane resin is generally a so-called prepolymer having a molecular weight of about 2,000 to 2,500 in order to improve the handleability and physical properties. For this prepolymer,
Usually, by reacting a large amount of diisocyanate of 10 parts by weight or more, physical properties that can be practically used are obtained. With the amount of the diisocyanate of 0.1 to 5 parts by weight proposed in the present invention, the existing prepolymer does not exhibit the practical physical properties. (C) In conventional polyurethane resin production, diisocyanate is added at room temperature or a temperature close thereto.
The use of masked diisocyanates found in paint baking requires temperatures to regenerate the diisocyanates, and when such temperatures are applied, if the diisocyanates are used as is, they are not desired during film formation. Since even gelation was exceeded, a uniform coating film could not be obtained, which was not practical. Therefore, according to the conventional wisdom, it was unthinkable to directly add diisocyanate at a high temperature (about 150 ° C. or higher) because it causes gelation trouble. In fact, when 10 parts by weight (based on 100 parts by weight of polyester) or more of diisocyanate is added to a prepolymer having a molecular weight of 2,000 to 2,500 at a temperature higher than the melting point of polyester, gelation is always caused. As seen in the present invention, a practical aliphatic polyester cannot be obtained unless the molecular weight of polyester and the amount of diisocyanate used are properly selected. The aliphatic polyester produced as described above has practically sufficient strength and flexibility, and also has a high melting point, so various molding methods can be used according to various applications. For example, when a film is formed using this, a known film forming method can be used, and there is no particular limitation. Further, at the time of molding, various molding aids such as fillers (inorganic or organic), colorants, reinforcing materials, waxes, thermoplastic polymers, oligomers and the like can be used in combination depending on the application.

[0008]

EXAMPLES The present invention will be described below with reference to examples. Example 1 A 1-liter separable flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas introduction tube was charged with 1,4-butanediol 2
50 g, 290 g of succinic acid, and 0.05 g (about 0.01 phr) of tetraisopropoxytitanium were charged, and in a nitrogen stream, 21
After esterification at 0-220 ° C to make the acid value 7.9,
Finally, the pressure was reduced to 0.6 Torr, the deglycolization reaction was carried out at 215 to 220 ° C for 8 hours, and the result of GPC analysis using saturated polyester (A) having a molecular weight of 14,900 (Shodex GPC SYSTEM-11, Showa Denko KK) )was gotten. When this polyester (A) was cooled to room temperature, it became a white wax. The melting point was 110-115 ° C. Remaining polyester (A) obtained by removing 10 g of polyester (A)
The whole amount (calculated amount 440 g) was heated and melted at 200 to 202 ° C., and 5 g of hexamethylene diisocyanate was added thereto. The viscosity increased rapidly. The mixture was stirred while maintaining the temperature, taken out after 10 minutes, and cooled to room temperature to obtain a polyester (B) having a high molecular weight and containing a small amount of urethane bond. Polyester (B) cooled to room temperature was in the form of white wax. The melting point was 113 to 115 ° C. and the molecular weight was 31,000. Each of the polyesters (A) and (B) was formed into a sheet between polyethylene terephthalate films having a thickness of 200 μm at 150 ° C. under a pressure of 10 kg / cm ² . Each of the obtained sheets having a thickness of 120 to 130 μ was biaxially stretched to form a film, but the sheet of Polyester (A) was cut during the stretching, and the film was not obtained. Polyester (B) sheet can be biaxially stretched and has a thickness of 30
A ~ 40μ transparent film was formed. Its tensile strength (measured by JISK6760) was 340 kg / cm ² .

Example 2 250 g of 1,4-butanediol, 232 g of succinic acid, 58 g of adipic acid, and tetraisopropoxytitanium were placed in a 1-liter separable flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas inlet tube. After 0.02 g (about 0.004 phr) was charged, the acid value was adjusted to 9.1 by esterification in a nitrogen stream at 210 to 215 ° C, and finally the pressure was reduced to 0.5 Torr at 210 to 215 ° C. The glycol removal reaction was carried out for a period of time to obtain a saturated polyester (C) having a molecular weight of 16400 (by GPC measurement). When this polyester (C) was cooled to room temperature, it became a white wax with a slight yellowish brown color. The melting point was about 95 ° C. The total amount of polyester (C) was melted by heating to 200 ° C., and 6 g of isophorone diisocyanate was added thereto. After stirring for 10 minutes and cooling to room temperature, the obtained urethane bond-containing polyester (D) is in the form of a light tan wax and has a melting point of about 95.
° C, the molecular weight was 34,000.

Example 3 A 2-liter separable flask equipped with a stirrer, a fractionating condenser, a thermometer, and a gas introduction tube was charged with 495 g of 1,4-butanediol, 406 g of succinic acid, 339 g of dodecanoic acid, and titanium tetrabutoxide of 0.025. Charge g (about 0.002 phr),
After esterification at 210 to 215 ° C. in a nitrogen stream to adjust the acid value to 6.8, the pressure was finally reduced to 0.6 Torr, and 21
A deglycol reaction was performed at 0 to 215 ° C. for 10 hours. The saturated polyester (E) obtained by cooling to room temperature had a molecular weight of 16,600, a melting point of about 80 ° C., and was a white wax. To this polyester (E), 12 g of diphenylmethane diisocyanate was added at 205 ° C. The polyester (F) containing a urethane bond obtained by stirring for 10 minutes and then cooling to room temperature was a yellowish brown wax and had a melting point of 82.
The molecular weight was ˜83 ° C. and 39,000.

[0011]

The present invention provides a method for producing an aliphatic polyester which has practically sufficient strength, has a high melting point, and can use a very small amount of catalyst.

Claims (1)

[Claims] 1. 1,4-butanediol and 50 to 100
Obtained by esterification with mol% succinic acid and 50-0 mol (%) at least one dicarboxylic acid selected from adipic acid, sebacic acid and dodecanoic acid, and subjecting the resulting esterified product to a deglycol reaction. When producing a saturated polyester (I) having a number average molecular weight of 5,000 or more and a terminal group which is substantially a hydroxyl group, 0.00
Using 01 parts by weight to 0.01 parts by weight of an organic alkoxytitanium compound as a catalyst, 0.1 part by weight to 5 parts by weight of diisocyanate is reacted with 100 parts by weight of the obtained saturated polyester (I), Finally number average molecular weight
A method for producing an aliphatic polyester containing a urethane bond, which comprises 10,000 or more.