JPH0357133B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a low melting point polyester polyol resin that is liquid or easily meltable at room temperature, has excellent workability, and has a low melting point. Recently, polyurethane resins have been used in foams, adhesives,
It has been used in many fields such as elastomers and paints. Polyurethane is mainly synthesized from polyisocyanate and polyol, but the polyol used in the largest amount is PPG.
Polypropylene glycol or its ethylene oxide modified product. The reason is that it is the cheapest. Furthermore, since PPG is a liquid at room temperature, it has the advantage of being extremely easy to handle and has excellent water resistance. However, since it has serious drawbacks such as poor heat resistance, weather resistance, mechanical properties, etc., it cannot be used in the polyurethane field where such performance is required. Therefore, polyester-based polyols are used in such fields. For example, polyester polyols synthesized from ethylene glycol and adipic acid, polyester polyols synthesized from 1,4-butylene glycol and adipic acid, and polycaprolactone polyols made from ε-caprolactone are commonly used. ing. However, with the exception of ε-caprolactone polyester, ethylene glycol/adipic acid polyester polyols and 1,4-butylene glycol/adipic acid polyesters have a drawback of very poor water resistance. Furthermore, these polyester polyols
Generally, when the molecular weight is 1000 or more, it is a wax-like solid with a melting point of 40 to 60°C, so it is difficult to use it in applications that require a liquid state at room temperature or in winter. In addition, when producing various polyurethane resins, it is necessary to melt the polyester polyol beforehand.
In addition, it was necessary to insulate the tank, piping, etc., and the workability was extremely poor. The present inventors have conducted intensive studies to solve these problems and develop a polyester polyol that has a low melting point and excellent water resistance, and as a result has arrived at the present invention. That is, in the present invention, 30 to 100% by weight of a polyhydric alcohol having 3 to 10 carbon atoms having a side chain is subjected to a dehydration esterification reaction with a polybasic acid or its anhydride, and then the obtained polyester polyol and ε-caprolactone are combined. ε-caprolactone, characterized by subjecting it to a transesterification reaction,
This is a method for producing a polyester polyol resin containing 80% by weight and having a melting point of 20°C or less. Among the polyhydric alcohols used in the present invention, the polyhydric alcohols having a side chain of 3 to 10 carbon atoms include 1,2-propylene glycol, 1,3-butylene glycol, neopentyl glycol, and hydroxypivalic acid of neopentyl glycol. ester, 2-methyl-1,3 propanediol,
2,3,5-trimethylpentanediol, trimethylolpropane, trimethylolethane, etc. can be used. Examples of polyhydric alcohols without side difference that can be used in the range of 0 to 70% by weight include ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butylene diol, 1,5-pentanediol, 1 ,6
-hexanediol etc. can be used. Polyhydric alcohol with 3 or more carbon atoms and a side chain
It is not preferable that the polyhydric alcohol of 10 is less than 30% by weight because the melting point of the polyester polyol of the present invention becomes high. Examples of the polybasic acid or anhydride thereof which is the second component of the polyester polyol of the present invention include maleic acid, succinic acid, fumaric acid, adipic acid, sepadic acid, azelaic acid, dodecanedioic acid, phthalic acid,
Isophthalic acid, terephthalic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, trimellitic acid, or anhydrides thereof, etc. can be used, but it is particularly difficult to use adipic acid. Preferred for the purpose of obtaining melting point resins. The third component, ε-caprolactone, is produced industrially by oxidizing cyclohexanone with a peracid such as hydrogen peroxide or peracetic acid by a Bayer-Billiker reaction. In the present invention, it is necessary that the resin contains 30 to 80% by weight of ε-caprolactone. If ε-caprolactone is less than 30% by weight,
The water resistance and low-temperature properties of the resulting resin deteriorate.
Moreover, if the amount is more than 80% by weight, the melting point of the polyester will become 20° C. or higher due to the crystallinity of borocaprolactone, which is not preferable. In the present invention, oxycaproic acid, which is a ring-opened product thereof, can be used instead of ε-caprolactone. Other cyclic lactones such as trimethylcaprolactone and valerolactone can also be copolymerized. The hydroxyl value of the polyester polyol of the present invention is 10 to 1000 KOHmg/g, preferably 20 to 1000 KOHmg/g.
It is 600KOHmg/g. This is because having a hydroxyl group in this range is convenient for applications such as polyurethane foams and polyurethane elastomers. Now, a method for synthesizing the polyester polyol of the present invention will be described. The most basic method is to first synthesize a polyester polyol with a terminal hydroxyl group from a polyhydric alcohol and a polybasic acid, then to synthesize a lactone-grafted polyester polyol by subjecting the hydroxyl group to ring-opening polymerization of ε-caprolactone. In this method, a transesterification reaction is caused between a polybasic acid ester chain and a polycaprolactone chain to obtain a random copolymerized polyester polyol of polybasic acid/polyhydric alcohol/lactone. At this time, it is difficult to effectively lower the melting point if the block copolymer is used as is. Therefore, in order to synthesize a lactone-modified polyester polyol with a low melting point, it is necessary to cause a sufficient transesterification reaction to form a random copolymer as described above. Therefore, the synthesis reaction of the polyester polyol of the present invention basically involves (1) an esterification reaction by dehydration from a polybasic acid and a polyhydric alcohol, (2) a ring-opening reaction of ε-caprolactone to a hydroxyl group, ( 3) A reaction in which ε-caprolactone is ring-opened by ester-forming water to become oxycaproic acid, which further undergoes dehydration and esterification with hydroxyl groups and carboxyl groups; (4) intramolecular and intermolecular transesterification reactions of polyester; It consists of two reactions. That is, the method of the present invention is a method in which a polyester polyol with a small molecular weight is first synthesized from a polyhydric alcohol and a polybasic acid, and then ε-caprolactone is graft-polymerized and a transesterification reaction is performed. This can significantly shorten the reaction time. Reaction temperature is 130℃~240℃, preferably 140~230℃
It is ℃. Also, passing an inert gas such as nitrogen gas during the reaction gives good results on the color of the resin, etc. For this reaction, titanium compounds such as tetrabutyl titanate, tetrapropyl titanate, dibutyltin laurate, tin octylate, dibutyltin oxide, stannous chloride, stannous bromide, stannous iodide are used as ring-opening reaction catalysts for caprolactone. It is preferable to use 0.01 to 1000 ppm of tin or the like. Furthermore, among these catalysts, titanium-based compounds in particular exhibit sufficient catalytic activity for transesterification reactions. The low melting point polyester polyol resin obtained by the present invention can be used as a raw material for various polyurethanes by reacting with polyisocyanates, polyhydric alcohols, polyhydric amines, etc. Further, this can be reacted with a polyisocyanate and a (meth)acrylic acid ester having a hydroxyl group to obtain a liquid polyfunctional acrylic urethane oligomer. It can also be used as a plasticizer for vinyl chloride resin. The present invention will be further explained with reference to examples below, but the present invention is not limited to these. Example Chubu means parts by weight. Synthesis Example 1 4138 parts of adipic acid and neopentyl glycol were placed in a 4-neck flask equipped with a nitrogen inlet tube, a thermometer, a condenser for removing ester-formed water, and a stirring device.
4863 parts and 0.08 parts of tetrabutyl titanate were charged, and a dehydration esterification reaction was carried out at 140°C to 220°C for 35 hours, resulting in an acid value of 0.6KOHmg/g and a hydroxyl value.
A polyester polyol of 249 KOHmg/g (units will be omitted below) was obtained. Example 1 24.4 parts of the neopentyl glycol/adipic acid polyester polyol obtained in Synthesis Example 1, 748 parts of ε-caprolactone, and 172.2 parts of ethylene glycol
parts, add 0.07 parts of tetrabutyl titanate, 190 parts
The mixture was heated and stirred at °C for 15 hours, and a liquid polyester polyol having a hydroxyl value of 88.6, an acid value of 0.4, and a hue of 100 (APHA) was obtained by ring-opening polymerization and transesterification of ε-caprolactone. The melting point of this thing is
The temperature was 10-12℃. Example 2 Polyester polyol 3318 obtained in Synthesis Example 1
5,884 parts of ε-caprolactone, and 0.06 parts of tetrabutyl titanate were heated and stirred at 190°C for 15 hours to form ε-
A random copolymer of neopentyl glycol, adipic acid, and ε-caprolactone was obtained by ring-opening polymerization of caprolactone and transesterification. This one has a hydroxyl value of 88.9, an acid value of 0.2,
The color was 90 (APHA) and the melting point was 2-3°C. Synthesis Example 2 Using the same equipment as Synthesis Example 1, adipic acid 3540
1 part, 3466 parts of neopentyl glycol, and 0.053 parts of tetrabutyl titanate were dehydrated and esterified at 140 to 220°C for 27 hours to obtain a hydroxyl value of 159.4,
A polyester polyol with an acid value of 0.54 was obtained. Example 3 Polyester polyol 2369 obtained in Synthesis Example 2
parts, 116.2 parts of ethylene glycol, 7918 parts of ε-caprolactone, and 0.08 parts of tetrabutyl titanate.
By heating and stirring at 220℃ for 8 hours, hydroxyl value 56.3, acid value 0.6, hue 80 (APHA), melting point 14-15
℃ polyester polyol was obtained. Example 4 Polyester polyol 3364 obtained in Synthesis Example 2
By heating 6236 parts of ε-caprolactone and 0.063 parts of tetrabutyl titanate at 190℃ for 15 hours, a hydroxyl value of 55.4, an acid value of 0.3, a hue of 85 (APHA),
A polyester polyol having a melting point of 4 to 5°C was obtained. In addition, when heating at 190℃ for only 5 hours,
Due to insufficient transesterification, the melting point is 15℃,
After heating for 8 hours, the temperature was 8°C. Comparative Example 1 269 parts of adipic acid, 228 parts of 1,4-butylene glycol, 510 parts of ε-caprolactone, and 0.01 part of tetrabutyl titanate were heated and stirred at 150°C to 230°C for 51 hours while dehydrating, resulting in an acid value of 1.3 and a hydroxyl value. A polyester polyol of 56.3 was obtained. However, the melting point of this product was 32°C. Comparative Example 2 143 parts of adipic acid, 152 parts of 1,4-butylene glycol, 740 parts of ε-caprolactone, and 0.01 part of tetrabutyl titanate were heated and stirred at 150°C to 230°C for 50 hours while dehydrating, resulting in a hydroxyl value of 55.5 and an acid value. A polyester polyol of 0.8 was obtained. However, the melting point of this product was 34°C. Comparative Example 3 143 parts of adipic acid, 100 parts of ethylene glycol,
780 parts of ε-caprolactone and 0.01 part of tetrabutyl titanate were heated and stirred at 150° C. to 230° C. for 30 hours while dehydrating for 50 hours to obtain a polyester polyol having a hydroxyl value of 57 and an acid value of 0.3. The melting point of this product was 38°C. Comparative Example 4 By reacting 63.5 parts of ethylene glycol with 1186 parts of ε-caprolactone in the presence of 0.00125 parts of tetrabutyl titanate at 210°C for 6 hours,
Polycaprolactone diol with a hydroxyl value of 90.0 and an acid value of 0.2 was obtained. This product was a waxy solid with a melting point of 43-45°C. Comparative Example 5 1,938 parts of ε-caprolactone was added to 63.5 parts of ethylene glycol in the presence of 0.001 part of stannous chloride.
By reacting at ℃ for 6 hours, the hydroxyl value
Polycaprolactone diol with an acid value of 56.1 and an acid value of 0.1 was obtained. This product was a waxy solid with a melting point of 45-55°C. Application example 1 100 parts of the lactone-modified polyester polyol obtained in Example 4 was added with silicone resin (Toray silicone).
SH-19) 1.5 parts, N-ethylmorpholine 1.0 parts,
After adding 0.03 parts of dibutyltinlaurate and 3.5 parts of water at room temperature and stirring well, tolylene diisocyanate (trade name TDI-80 manufactured by Nippon Polyurethane Co., Ltd.) was added.
When 43.8 parts were added and mixed and stirred, it generated heat and foamed, yielding a good soft urethane foam with a density of 31 kg/m ³ . Application example 2 4,4'-diphenylmethane diisocyanate (MDI) and chain extender 1, A polyurethane resin was obtained by reacting 4-butylene glycol. The results are shown in Table 1.

[Table] Calculated as softening temperature.
Comparative Example 6 Using the same equipment as in Synthesis Example 1, adipic acid 4138
parts, neopentyl glycol 4863 parts, ε-caprolactone 14153 parts, tetrabutyl titanate 0.221 parts
and heated from 140℃ to 220℃ until the acid value
The dehydration condensation reaction was carried out until the value became 1.0 or less. The time required for synthesis was 72 hours. Acid value 0.53KOH
A liquid polyester polyol with mg/g, hydroxyl value of 90.1, and hue (APHA) of 150 was obtained. The melting point of this product was 1-3°C. Comparative Example 7 Using the same equipment as in Synthesis Example 1, adipic acid 3540
parts, neopentyl glycol 3466 parts, ε-caprolactone 11369 parts, tetrabutyl titanate 0.175 parts
and heated from 140℃ to 220℃ until the acid value
The dehydration condensation reaction was carried out until the value became 1.0 or less. The time required for synthesis was 65 hours. A polyester polyol having an acid value of 0.50, a hydroxyl value of 56.3, a hue of 120 (APHA), and a melting point of 3 to 6°C was obtained. Application example 3 In the low melting point lactone modified polyester polyol synthesized by batch charging in Comparative Examples 6 and 7,
MDI and 1,4-butylene glycol were reacted in the same manner as in Application Example 2 to obtain a polyurethane resin. Comparative Examples 6 and 7 were carried out in the same manner as in Example 2 and Example 4, respectively, in which the amounts of reaction components were charged and the polyurethane was mixed. The results are shown in Table 2 in comparison with those of Examples 2 and 4.

【table】

Claims (1)

[Claims] 1 3-10 carbon atoms with 30-100% by weight having side chains
A polyhydric alcohol and a polybasic acid or an anhydride thereof are subjected to a dehydration esterification reaction, and then the obtained polyester polyol and ε-caprolactone are subjected to a transesterification reaction,
A method for producing a polyester polyol resin containing 30 to 80% by weight of caprolactone and having a melting point of 20°C or less.