JPH0570576A - Production of 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. used 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 0.0001-0.1 pt.wt. titanium (oxy) acetylacetonate 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 alids followed by the elimination of the glycol molecules. Then, 100 pts.wt. the ailph. polyester is reacted with 0.1-5 pts.wt. diisocyanate to give the title polyester.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is useful for forming films, fibers, and other molded articles which have practically sufficient strength, have a high melting point, and can use a very small amount of catalyst. The present invention relates to a method for producing an aliphatic polyester.

[0002]

BACKGROUND OF THE INVENTION Aliphatic polyesters have a low melting point, and even if the number average molecular weight is in the high molecular weight region of 10,000 or more, a polyester containing a saturated aromatic structure,
For example, polyethylene terephthalate, which does not exhibit practically sufficient mechanical properties, has been considered to be impractical until now. In fact, even if the film has a film-forming property, the produced film was weak in tear strength and tensile strength and was not practically usable. Among these, 1,4-
Aliphatic polyesters containing butanediol as a glycol component are relatively strong, and have adipic acid, sebacic acid,
It has been found that esterification with an aliphatic dicarboxylic acid such as dodecanoic acid can produce a film-forming polyester, although it does not have sufficient strength. 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 by using 1,4-butanediol and succinic acid is crystalline and is subjected to usual esterification and deglycolization reaction to obtain a number average molecular weight.
Even at 10,000 to 15,000, a slightly fragile tendency is recognized. 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 other heavy metal organic or inorganic 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 a practically sufficient strength and a high melting point, and can use a very small amount of a catalyst, and an aliphatic compound having a film-forming property. It is intended to provide a method for producing polyester.

[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) is used.
0001 parts by weight to 0.01 parts by weight of titanium (oxy) acetylacetonate as a catalyst, and 0.1 parts by weight to 100 parts by weight of the obtained saturated polyester (I).
The present invention provides a method for producing a polyester having a urethane bond, which comprises reacting 5 parts by weight of diisocyanate and finally making the number average molecular weight 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,
In addition, when adipic acid, sebacic acid, or dodecanoic acid is used in combination, if necessary, 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, a certain titanium-based catalyst was found to produce 100 wt. It was found that even a small amount of 0.01 parts by weight or less with respect to 10 parts by weight is effective, and further it was found that it is effective to react the obtained saturated polyester with diisocyanate, and the present invention can be completed. It was 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 1 succinic acid or a mixed acid of succinic acid and at least one dicarboxylic acid selected from adipic acid, sebacic acid and dodecanoic acid.
The amount is substantially equimolar with respect to 00 mol%, but since there is distilling during esterification in general, it is used in an 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. , Preferably 60
Mol% or more, 50 mol% of dicarboxylic acid such as adipic acid
Hereafter, it is 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 used in the present invention has a structural formula

[0006]

[Chemical 1]

It is titanium (oxy) acetylacetonate represented by: The amount of this catalyst used is 0.0001 to 0.01 with respect to 100 parts by weight of a saturated polyester obtained by reacting 1,4-butanediol with succinic acid, and optionally with adipic acid, sebacic acid or dodecanoic acid. The amount is preferably 0.001 part by weight to 0.01 part by weight. 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 saturated polyester obtained as described above needs to have a molecular weight of 5,000 or more. When the saturated polyester has a molecular weight of less than 5,000,
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 obtain 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 2000 to 2500 in order to improve the handleability and physical properties. By reacting the prepolymer with 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 baking paints requires a temperature at which the diisocyanates are regenerated, and when such temperatures are applied, if the diisocyanates are used as is, they are not desired during film formation. Since a gelation was caused, a uniform coating film could not be obtained, which was not practical. Therefore, the conventional wisdom is that
Direct addition of diisocyanate at a high temperature (about 150 ° C. or higher) was unthinkable 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 aliphatic polyester, a known film forming method can be used, and there is no particular limitation. Further, at the time of molding, various molding auxiliaries such as fillers (inorganic or organic), colorants, reinforcing materials, waxes, thermoplastic polymers, oligomers, etc. can be used together depending on the application.

[0010]

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 titanium (oxy) acetylacetonate were charged, and the acid value was 9.6 by esterification at 210 to 220 ° C in a nitrogen stream.
After that, the pressure is finally reduced to 0.5 Torr, and 215-
Deglycol reaction at 220 ℃ for 8 hours, molecular weight 16,1
00 saturated polyester (A) (Shodex GPC SYSTEM-1
1, the result of GPC analysis using Showa Denko) was obtained. When this polyester (A) was cooled to room temperature, it became a white wax. The melting point was 113 ° C. After removing 10 g of the polyester (A), the total amount of the remaining polyester (A) was heated and melted at 200 to 202 ° C., and 6 g of hexamethylene diisocyanate was added in this state. The viscosity increased rapidly. After 10 minutes, a high molecular weight aliphatic polyester (B) containing a urethane bond, which had flowed out onto the vat and solidified, was obtained. Polyester (B) cooled to room temperature was in the form of white wax. Melting point is 113-
The molecular weight was 115 ° C and the molecular weight was 33,000. Polyesters (A) and (B) were respectively placed between polyethylene terephthalate films having a thickness of 200 μ, at 150 ° C., 10 kg /
Sheets were formed under a pressure of cm ² . The obtained thickness 120
An attempt was made to biaxially stretch each sheet having a thickness of ˜130 μ four times in the lengthwise and widthwise directions to form a film, but the sheet of polyester (A) broke during the stretching and a film could not be obtained. The sheet of polyester (B) could be biaxially stretched, and a transparent film having a thickness of about 30 μ was formed. Its tensile strength (measured by JIS K6760) is 3
It was 60 kg / cm ² .

Example 2 250 g of 1,4-butanediol, 232 g of succinic acid, 58 g of adipic acid and titanium (oxy) were placed in a 1-liter separable flask equipped with a stirrer, a fractionating condenser, a thermometer and a gas inlet tube. Acetylacetonate 0.02g (about 0.004
phr) and esterified at 210-215 ° C in a nitrogen stream to give an acid value of 6.7, and finally 0.5 Torr.
Saturated polyester (C) having a molecular weight of 16,900 by deglycolizing at 210-215 ° C for 12 hours.
(By GPC measurement) was obtained. 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 heated and melted at 205 ° C., and 7 g of isophorone diisocyanate was added thereto to obtain polyester (D) containing a urethane bond. Polyester (D) cooled to room temperature is in the form of a light tan wax,
The melting point was about 95 to 96 ° C. and the molecular weight was 38,000.

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 (oxy). Acetylacetonate 0.025g (about 0.002
phr) and esterified in a nitrogen stream at 210 to 215 ° C. to an acid value of 7.9, and finally 0.5 Torr
The mixture was depressurized to 210 ° C. and deglycolized at 210 to 215 ° C. for 10 hours. The saturated polyester (E) obtained by cooling to room temperature had a molecular weight of 15,900, a melting point of about 80 ° C., and was a white wax. The total amount of this Polyester (E) is 2
It melted at 00 to 201 ° C., and 12 g of diphenylmethane diisocyanate was added thereto. After stirring for 10 minutes, the urethane bond-containing polyester (F) obtained by cooling to room temperature is a yellowish brown wax and has a melting point of 81 to 82 ° C.
The molecular weight was 39,000.

[0013]

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, 0.0001 is added to 100 parts by weight of the saturated polyester (I).
Using 0.1 part by weight to 0.01 part by weight of titanium (oxy) acetylacetonate 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). And a final number average molecular weight of 10,000 or more. A method for producing a polyester containing a urethane bond.