JP3144435B2 - Method for producing polyester polyol and curable resin composition - 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 polyester polyol which is liquid at room temperature and has a low viscosity in a short time, and further has a high strength, hydrolysis resistance and mold resistance using the same. The present invention relates to a curable resin composition from which a cured product having excellent properties can be obtained.

[0002]

2. Description of the Related Art Polyurethane resins are excellent in elasticity, flexibility, abrasion resistance and the like, and are used in many fields such as foams, elastomers, adhesives and paints. Polyurethane resin is mainly synthesized from a polyisocyanate and a polyol, among which the largest amount is used as a polyol is PPG, polypropylene glycol,
Or its ethylene oxide modified form. The reason is that not only is it inexpensive, but it also exhibits a low viscosity liquid at room temperature,
It is extremely easy to handle.

However, this PPG is not sufficient in heat resistance, weather resistance, mechanical properties, and the like, and polyester polyols are used in fields requiring such properties. Examples of the polyester polyol include adipate-based polyester polyols such as polyester polyols synthesized from ethylene glycol and adipic acid, polyester polyols synthesized from 1,4-butylene glycol and adipic acid, and polycaprolactone using ε-caprolactone as a raw material. A polyester polyester polyol or the like is generally used.

[0004] However, these polyester polyols generally have a melting point of 40 to 100 when the molecular weight is 1000 or more.
Since it is a wax-like solid at 60 ° C., it becomes difficult to use it for various applications that need to be liquid. Further, the viscosity at the time of melting is high, and the workability is extremely poor.

Many attempts have been made to obtain polyester polyols in which these problems have been improved. For example, as described in JP-A-57-164121, neopentyl glycol, 2-methyl-1,
A method has been proposed in which a polyester polyol obtained from a polyhydric alcohol having a side chain such as 3-propanediol is transesterified with ε-caprolactone to obtain a random copolymerized polyester polyol of polybasic acid / polyhydric alcohol / lactone. .

[0006]

However, in such a method for producing a random copolymerized polyester polyol, a polyester polyol which is liquid at room temperature can be obtained, but the melt viscosity is as high as that of a general polyester polyol.
There is also a problem that transesterification takes a long time.

The cured product obtained by reacting the thus obtained polyester polyol having a side chain such as neopentyl glycol with an organic polyisocyanate does not have satisfactory hydrolysis resistance, and There was also a drawback that mold resistance was not good.

[0008]

DISCLOSURE OF THE INVENTION The present inventors have developed a method for producing a polyester polyol having a low viscosity at room temperature in a liquid state in a short time, and a polyurethane resin having high physical properties and excellent hydrolysis resistance and mold resistance. As a result of intensive studies, the reaction was carried out to obtain a block copolymerized polyester polyol with lactone using 3-methyl-1,5-pentanediol as an essential component as a polyol having an alkyl group in the side chain. The reaction can be completed in a shorter time as compared with the production of a block cocondensation polyol of lactone and lactone, and the obtained lactone-modified polyester polyol can have an extremely low melt viscosity as compared with that. I found

Further, a cured product containing 3-methyl-1,5-pentanediol as an essential component and containing a lactone and a random co-condensed polyester polyol or a block co-condensed polyester polyol component is more resistant to curing than conventional cured products. It has been found that not only hydrolytic properties but also mold resistance are extremely good.

In this way, the present inventors have completed the above two inventions. That is, the present invention relates to 3-methyl-
A process for producing a lactone-modified polyester polyol in which a polyhydric alcohol containing 1,5-pentanediol as an essential component is subjected to a dehydration esterification reaction with a polybasic acid or an anhydride thereof, and then the resulting polyester polyol is subjected to ring-opening polymerization of a lactone. , An organic polyisocyanate (A) and 3
Resin composition comprising a polyester polyol (B) obtained by using -methyl-1,5-pentanediol and a lactone as essential components, an organic polyisocyanate (A), and 3-methyl-1,5-pentanediol Curable resin composition comprising an isocyanate group-terminated urethane prepolymer (I) obtained by reacting a polyester polyol (B) obtained by using a polyester polyol (B) with lactone as an essential component, and an active hydrogen compound (II) having at least two active hydrogens It provides things.

[0011]

In the present invention, 3-methyl-1,5-pentanediol is used as an essential component as a polyhydric alcohol.

Examples of polyhydric alcohols that can be used in combination with 3-methyl-1,5-pentanediol include, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 2,3-butanediol, 4
-Butanediol, 2,2'-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, cyclohexane 1,4
-Diol, cyclohexane 1,4-dimethanol and the like can be used. Further, a polyhydric alcohol such as trimethylolpropane, glycerin, pentaerythritol and the like may be used in combination with the above-mentioned diol, if necessary, without any problem.

Although 3-methyl-1,5-pentanediol may be used alone, it may generally be used in combination with other polyhydric alcohols. When other polyhydric alcohols are used in combination, it is preferable that 3-methyl-1,5-pentanediol be used in an amount of 60% by weight or more, and more preferably 80% by weight or more in all the polyols. Within this range, a polyester polyol having a lower melting point and a lower viscosity can be obtained in a short time, and the cured product finally obtained has high strength and excellent hydrolysis resistance and mold resistance. The effect of the present invention is fully exhibited.

The polybasic acid or anhydride as another component optionally used for condensation with 3-methyl-1,5-pentanediol includes, for example, succinic acid, maleic acid, adipic acid, glutaric acid and the like. Acid, pimelic acid, spearic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid or their anhydrides alone or in combination of two or more Can be used.

From an industrial point of view, adipic acid is mainly used. As the lactone in the present invention, any known and commonly used lactone can be used, for example, butyrolactone, δ-valerolactone, β-methyl-δ-valerolactone, ε-caprolactone or a ring-opened product thereof, alone or
More than one species can be used in combination. Among them, ε-caprolactone is most preferred. In the present invention, the lactone is added to the lactone-modified polyester polyol in an amount of 30 to
It is preferred to contain 80% by weight. A lactone-modified polyester polyol in this range is preferable because it has good physical properties when finally cured, has low crystallinity, and has a melting point below room temperature.

The molecular weight of the lactone-modified polyester polyol obtained by the production method of the present invention is usually 500 to 50.
00, preferably 500 to 3000, and those having a molecular weight of these are suitable as a raw material for urethane resin.
The acid value and the water content are preferably as low as possible for the urethane resin raw material.

In order to synthesize the lactone-modified polyester polyol of the present invention, for example, first, 3-methyl-1,5-
A polyhydric alcohol containing pentanediol as an essential component is subjected to a dehydration esterification reaction with a polybasic acid or an anhydride thereof, and then the resulting polyester polyol is subjected to ring-opening polymerization of lactone to obtain a polybasic acid / polyhydric acid. A block copolymerized polyester polyol of a polyester of alcohol and a lactone can be obtained.

In the above method for producing a lactone-modified polyester polyol for obtaining a block copolymerized polyester polyol, there is no need to carry out the reaction at a higher temperature for a longer time after the above-mentioned step to carry out random copolymerization of polybasic acid / polyhydric alcohol / lactone. Therefore, the reaction at the time of producing the random copolymerized polyester polyol using the same raw material can be completed in a shorter time.

The reaction temperature of the raw materials during the dehydration esterification and the addition of the lactone is usually 140 to 240 ° C., preferably 180 to 220 ° C. By passing an inert gas such as nitrogen gas through the liquid during the reaction, the hue of the polyester polyol can be favorably maintained. The condensation time of the polyester depends on the target molecular weight of the polyester polyol and the like, but is usually 8 to 20 hours. On the other hand, since the addition reaction of lactone is merely a block copolymerization, the reaction time required for the reaction is usually several hours.

In this reaction, any known catalyst such as titanium compounds such as tetrabutyl titanate and tetrapropyl titanate such as dibutyltin laurate, tin octylate, dibutyltin oxide and stannous chloride can be used. The amount used is generally 0.01-1000p
pm.

What has been described above is a method for producing a block copolymerized lactone-modified polyester polyol.
Next, the invention of a curable resin composition using the polyester polyol will be described.

The curable resin composition of the present invention comprises an organic polyisocyanate (A) and a polyester polyol (B) obtained by using 3-methyl-1,5-pentanediol and lactone as essential components (B). Usually called a one-shot method), an organic polyisocyanate (A),
Polyester polyol (B) obtained using 3-methyl-1,5-pentanediol and lactone as essential components
And a form (usually a prepolymer method) consisting of an isocyanate group-containing urethane prepolymer (I) reacted with an active hydrogen compound (II) having at least two active hydrogens.

In the invention of these curable resin compositions, as the lactone-modified polyester polyol (B), not only a block copolymerized lactone-modified polyester polyol but also a random copolymerized lactone-modified polyester polyol can be used. These may be used alone or in combination.

The cured product of the composition of the present invention is a polyurethane resin, which can be obtained by reacting the organic polyisocyanate (A) with the polyol (B) mainly as described above.
Active isocyanate-terminated urethane prepolymer (I) and active hydrogen compound (II) having at least two active hydrogens
And by reacting

The prepolymer (I) comprises an organic polyisocyanate (A) and a polyol (B), which will be described later, as essential components, and isocyanate groups and active hydrogen atoms thereof are reacted under reaction conditions in which the isocyanate groups become excessive. Can be easily obtained.

Regardless of the one-shot method or the prepolymer method, since the molecule has a skeleton of 3-methyl-1,5-pentanediol and lactone in the molecule, it has high strength, hydrolysis resistance, and resistance to hydrolysis. A polyurethane resin as a final cured product having excellent moldability can be obtained.

The reaction ratio of the components (A) and (B) and the reaction ratio of the components (I) and (II) in the above composition are not particularly limited, but usually the isocyanate group and the active hydrogen atom are equivalent. Each component is used as described above.

The organic polyisocyanate (A) mentioned here
As, for example, hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate,
Xylene diisocyanate, cyclohexane diisocyanate, toluidine diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, p
-Phenylene diisocyanate, m-phenylene diisocyanate, 1,5-naphthylene diisocyanate, triphenylmethane triisocyanate, and mixtures and modified products thereof.

In the one-shot method, in order to obtain a polyurethane resin as a cured product, an active hydrogen compound which can react with the polyisocyanate (A) may be used in addition to the polyol (B). Examples of the active hydrogen compound include active hydrogen compounds having at least two representative active hydrogens such as polyhydric alcohols and polyamines, and active hydrogens other than (II) such as monoalcohols and secondary amines. Compounds can be mentioned. In the prepolymer method,
In addition to the active hydrogen compound (II), other active hydrogen compounds may be used in combination.

The polyhydric alcohol used at this time includes
All the above-mentioned polyhydric alcohols including 3-methyl-1,5-pentanediol can be used. Examples of the polyvalent amine include amines such as ethylenediamine, hexamethylenediamine, diethyltoluenediamine, and 3,3′-dichloro-4,4′-diaminodiphenylmethane, and alkanolamines such as ethanolamine and propanolamine.

In addition to the organic polyisocyanate (A) and the polyol (B), or the prepolymer (I) and the active hydrogen compound (II), the curable resin composition of the present invention may further comprise, if necessary, a known foam. Agents, catalysts, reaction retarders, surfactants such as emulsifiers and foam stabilizers, pigments, dyes, flame retardants, stabilizers against aging and exposure, plasticizers, fillers such as calcium carbonate, and the like can all be used.

The curable resin composition of the present invention provides a cured product having high strength and excellent hydrolysis resistance and mold resistance.
It can be used for many purposes such as foam, thermosetting and thermoplastic elastomers, paints, adhesives, synthetic leather, flooring and other building materials.

Next, the present invention will be described with reference to examples.
This is only one mode, and the present invention is not limited only by the examples. Also in the sentence "part"
All “%” are based on weight.

[0034]

【Example】

Example 1 (Synthesis of block copolymerized lactone-modified polyester polyol) 1,300 parts of 3-methyl-1,5-pentanediol, 978 parts of adipic acid, 0.026 of tetrabutyl titanate
Parts, and passing nitrogen gas under normal pressure, about 220 ° C
For 10 hours while distilling off condensed water to obtain a polyester polyol having a hydroxyl value of 225.8 KOH mg / g and an acid value of 0.9 KOH mg / g.

Further, ε-caprolactone 2012
Parts, 0.010 part of tetrabutyl titanate,
Heat and stir at 0 ° C for 2 hours.
-Caprolactone was added by ring-opening polymerization to obtain a polyester polyol of a block copolymer. Hydroxyl value 11
2.0 KOH mg / g, acid value 0.7 KOH mg / g, hue (APHA) 70, water content 0.008%, melt viscosity (a
(t75 ° C) 95 cps, melting point was about 3 ° C. Example 2 (same) 780 parts of 3-methyl-1,5-pentanediol, 587 parts of adipic acid and 0.016 part of tetrabutyl titanate were charged, and condensed at about 220 ° C. for 9 hours while passing nitrogen gas under normal pressure. A dehydration esterification reaction was performed while distilling water, and the hydroxyl value was 223.1 KOH mg / g and the acid value was 0.6.
A polyester polyol of KOH mg / g was obtained.

Further, ε-caprolactone 2873
Parts, and 0.006 parts of tetrabutyl titanate.
Heat and stir at 0 ° C for 3 hours.
-Caprolactone was added by ring-opening polymerization to obtain a polyester polyol of a block copolymer. Hydroxyl value
3 KOH mg / g, acid value 0.5 KOH mg / g, hue (APHA) 80, water content 0.011%, melt viscosity (at
(75 ° C.) 220 cps, melting point about 14 ° C. Example 3 (same) 1545 parts of 3-methyl-1,5-pentanediol, 1593 parts of adipic acid, 0.03 of tetrabutyl titanate
Charge one part and pass nitrogen gas under normal pressure, about 220
A dehydration esterification reaction was performed at 12 ° C. for 12 hours while distilling condensed water to obtain a polyester polyol having a hydroxyl value of 75.0 KOH mg / g and an acid value of 0.3 KOH mg / g.

Further, ε-caprolactone 1447
And 0.013 part of tetrabutyl titanate,
Heat and stir at 0 ° C for 3 hours.
-Caprolactone was added by ring-opening polymerization to obtain a polyester polyol of a block copolymer. Hydroxyl value
2 KOH mg / g, acid value 0.3 KOH mg / g, hue (APHA) 60, water content 0.007%, melt viscosity (at
75 ° C.) 490 cps, melting point about 1 ° C. Example 4 (same) 961 parts of 3-methyl-1,5-pentanediol, 1,
240 parts of 6-hexanediol, 1239 of adipic acid
And 0.024 part of tetrabutyl titanate, and a dehydration esterification reaction was carried out while distilling out condensed water at about 220 ° C. for 11 hours while passing nitrogen gas under normal pressure to obtain a hydroxyl value of 74.1 KOH mg / g, acid Value 0.4 KOHmg /
g of polyester polyol was obtained.

Furthermore, ε-caprolactone 2080
And 0.011 part of tetrabutyl titanate,
Heat and stir at 0 ° C for 3 hours.
-Caprolactone was added by ring-opening polymerization to obtain a polyester polyol of a block copolymer. Hydroxyl value 37.
4 KOH mg / g, acid value 0.3 KOH mg / g, hue (APHA) 50, water content 0.010%, melt viscosity (at
75 ° C.) 780 cps, melting point about 6 ° C. Example 5 (same) 1201 parts of 3-methyl-1,5-pentanediol, 1239 parts of adipic acid, 0.02 of tetrabutyl titanate
Charge 4 parts and pass nitrogen gas under normal pressure, about 220
A dehydration esterification reaction was performed at 11 ° C. for 11 hours while distilling off condensed water to obtain a polyester polyol having a hydroxyl value of 75.2 KOH mg / g and an acid value of 0.7 KOH mg / g.

Further, ε-caprolactone 2111
And 0.011 part of tetrabutyl titanate,
Heat and stir at 0 ° C for 3 hours.
-Caprolactone was added by ring-opening polymerization to obtain a polyester polyol of a block copolymer. Hydroxyl value 37.
7 KOH mg / g, acid value 0.4 KOH mg / g, hue (APHA) 80, moisture 0.009%, melt viscosity (at
75 ° C) 770 cps, melting point about 2 ° C. Comparative Example 1 (trace of JP-A-57-164121) 1128 parts of neopentyl glycol, adipic acid 133
3 parts, 0.022 parts of tetrabutyl titanate were charged,
While passing nitrogen gas under normal pressure, at about 220 ℃ for 10 hours,
The dehydration esterification reaction was carried out while distilling the condensed water, and the hydroxyl value was 74.7 KOHmg / g and the acid value was 0.6 KOHmg.
/ G of polyester polyol.

Further, ε-caprolactone 2097
And 0.011 part of tetrabutyl titanate,
The mixture was heated and stirred at 0 ° C. for 15 hours to add ε-caprolactone to the polyester polyol by ring-opening polymerization, and to obtain a polyester polyol of a random copolymer of neopentyl glycol, adipic acid and ε-caprolactone.
Hydroxyl value 37.6KOHmg / g, acid value 0.3KOHm
g / g, hue (APHA) 130, moisture 0.004%,
Melt viscosity (at 75 ° C) 1050 cps, melting point about 6 ° C
Met.

After the introduction of ε-caprolactone, 190
When only heating and stirring at 3 ° C for 3 hours, the melting point is about 21 ° C.
Met. [Application Example 1 to Polyurethane Resin 1-Prepolymer Method] 2,4-Tolylene diisocyanate was added to various polyester polyols synthesized in Examples 1 to 5 and Comparative Example 1 by NC
O / OH = 2/1 (equivalent ratio)
The reaction was carried out for a period of time to synthesize a urethane prepolymer having a terminal isocyanate group.

As a curing agent, 3,3 'is added to this prepolymer.
-Dichloro-4,4'-diaminodiphenylmethane (M
Using OCA), the mixture of the two components was poured into a mold to produce a urethane elastomer. At that time, the temperature of the prepolymer was adjusted to 80 ° C, the temperature of the curing agent was adjusted to 120 ° C, and NH ₂ / NCO was used.
= 0.90 / 1 (equivalent ratio). Aging is 110
C. for 10 hours. [Evaluation of Hydrolysis Resistance] A 2 mm-thick urethane elastomer sheet obtained in the application example was punched out with a dumbbell for measuring physical properties, immersed in warm water at 70 ° C. for a predetermined time, and evaluated for tensile strength retention after immersion. [Evaluation of mold resistance] On glucose peptone agar culture medium,
Attached with the urethane elastomer sheet of 2 mm thickness obtained in the application example, contacted with a mixed spore suspension of five molds, and cultured at 30 ° C and 90-95% humidity to check the state of surface deterioration. Observed. Note that JIS Z 29
Asbestos gills described in 11-1960 mold resistance test
Niger ATCC9642, Penicillium Luteum AT
CC9644, Resolves Nigirikans S .; N. 3
2. Five kinds of molds, Trichoderma T-1 ATCC9645 and Ketomium globosum ATCC6205, were used.

The results are summarized in Tables 1 and 2.

[0044]

[Table 1] As can be seen from Table 1, the reaction time of the method for producing a block copolymerized lactone-modified polyester polyol of the present invention is significantly shorter than that of a conventional method for producing a random copolymerized lactone-modified polyester polyol.

[0045]

[Table 2] As can be seen from Table 2, the cured polyurethane resin obtained by using the block copolymerized polyester polyol of the present invention as an essential component has a higher water resistance (which is a measure of hydrolysis resistance) and a higher mold resistance than conventional cured products. It can be seen that is much better. [Application Example 2 to Polyurethane Resin—One-Shot Method] Each polyester polyol, 1,4-butanediol and 4,4′-diphenylmethane diisocyanate (MDI) synthesized in Example 5 and Comparative Example 1 were combined with an active hydrogen atom. And isocyanate groups were reacted by a one-shot method so as to be equivalent, to produce a polyurethane elastomer. Using these elastomers, the same evaluation as in Application Example 1 was performed. Table 3 shows the results.

[0046]

[Table 3] As can be seen from Table 3, the polyurethane resin as a cured product obtained by using the block copolymerized polyester polyol of the present invention as an essential component has a higher water resistance (which is a measure of hydrolysis resistance) and a higher mold resistance than conventional cured products. It can be seen that is much better.

[0047]

According to the production method of the present invention, 3-methyl-
Since the block copolymerized lactone-modified polyester polyol is produced by using 1,5-pentanediol as an essential component, an extremely remarkable effect is obtained in which a product having a low viscosity can be obtained in a short time.

In the composition of the present invention, 3-methyl-
Since a raw material having a 1,5-pentanediol skeleton and a lactone skeleton as blocks or at random is used, a cured product obtained by curing it is excellent not only in hydrolysis resistance but also in mold resistance. Has a remarkable effect.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 18/42 C08G 63/00-63/91

Claims (6)

(57) [Claims] 1. A polyhydric alcohol containing 3-methyl-1,5-pentanediol as an essential component and a polybasic acid or an anhydride thereof are subjected to a dehydration esterification reaction, and then a lactone is ring-opened in the obtained polyester polyol. A method for producing a lactone-modified polyester polyol to be polymerized. 2. A curable resin composition comprising an organic polyisocyanate (A) and a polyester polyol (B) obtained by using 3-methyl-1,5-pentanediol and lactone as essential components. 3. An isocyanate-terminated urethane prepolymer (I) obtained by reacting an organic polyisocyanate (A) with a polyester polyol (B) obtained by using 3-methyl-1,5-pentanediol and lactone as essential components. ) And an active hydrogen compound (II) having at least two active hydrogens. 4. A polyester polyol (B) obtained by subjecting a polyhydric alcohol having 3-methyl-1,5-pentanediol as an essential component to a dehydration esterification reaction with a polybasic acid or an anhydride thereof, and then obtaining the polyester polyol (B). The composition according to claim 2 or 3, which is a lactone-modified polyester polyol obtained by subjecting a lactone to ring-opening polymerization of a polyester polyol. 5. A polyhydric alcohol comprising 3-methyl-1,5.
The curable resin composition according to claim 2, wherein pentanediol is used in an amount of 60 to 100% by weight. 6. The polyurethane resin composition according to claim 2, wherein the lactone content in the polyester polyol is 30 to 80% by weight.