JP3235921B2 - Polyester polyol resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low melting point polyester polyol resin which is liquid at room temperature or can be easily dissolved.

[0002]

2. Description of the Related Art In recent years, polyurethane resins have been widely used in the fields of elastomers, paints, foam adhesives and the like. Various kinds of polyols are used for producing the polyurethane resin. Of these, polyether-based polyols such as polypropylene glycol, polyethylene glycol and polytetramethylene glycol are often liquid in the molecular weight range used for polyurethane production, are inexpensive, and have excellent cold resistance and water resistance. However, it has the disadvantage of being inferior in mechanical strength, oil resistance, heat resistance, and weather resistance.

On the other hand, polyester-based polyols such as poly (ethylene glycol adipate), poly (butylene glycol adipate) and polycaprolactone have excellent mechanical strength, oil resistance and heat resistance, which are disadvantages of polyether polyols. On the other hand, since it is crystalline, it is inferior in cold resistance and needs to be melted at the time of use, so that there is a problem in workability.

Among them, polycaprolactone polyol is prepared by copolymerizing a lactone with a polyester comprising a polyhydric alcohol having a side chain and a polybasic acid, as described in Japanese Patent Publication No. 3-57133. It is disclosed that its crystallinity is reduced, and cold resistance and workability during use are improved.

[0005]

However, in order to improve the weather resistance of the polyol and the polyurethane resin synthesized therefrom, an alicyclic high melting point diol component having no side chain such as cyclohexanedimethanol is used. In this case, or when a polyhydric alcohol having a side chain cannot be used from the viewpoint of the physical properties of the polyurethane resin, polycrystalline polycaprolactone polyol had to be used.

The present inventors have conducted intensive studies on the production of a non-crystalline, low-viscosity lactone-containing polyol using a polyol that satisfies the required performance, and have reached the present invention.

[0007]

That is, in a copolymer of a polyester polyol and a lactone compound, glutaric acid is contained as a carboxylic acid component of the polyester polyol in an amount of 100 to 30% by weight of the carboxylic acid component, and the content of the lactone is reduced. By setting the content to 20 to 80% by weight,
Even when a polyhydric alcohol having no side chain is used, 2
It has been found that a polyester polyol resin having a melting point of 5 ° C. or less can be produced.

In the present invention, as the polyhydric alcohol,
Various types of aliphatic branched, straight-chain, or alicyclic or aromatic alcohols can be used. For example, ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-
Butylene glycol, 1,4-butylene glycol, neopentyl glycol, 3-methylpentanediol,
1,5-pentanediol, 1,6-hexanediol, trimethylolpropane, cyclohexanedimethanol, 1,4-dibenzyl alcohol, and the like can be used.

Also, polybasic acids other than glutaric acid or anhydrides thereof include maleic acid, succinic acid, fumaric acid, adipic acid, sebacic acid, azelaic acid, dodecane diacid, phthalic acid, isophthalic acid, terephthalic acid, An ester of hexahydrophthalic acid, methylhexahydrophthalic acid, tetrahydrophthalic acid, trimellitic acid, methyltetrahydrophthalic acid or an anhydride thereof, or a low molecular alcohol such as methyl ether of the acid can be used as a raw material.

The lactones as the third component include ε-
Caprolactone, δ-valerolactone, β-methyl-δ
-Various lactones such as valerolactone, β-propiolactone, and γ-butyrolactone can be used alone or in combination, but ε- is industrially produced by a Bayer-Villiger reaction of cyclohexanone with a peracid.
Preferably, caprolactone is used.

In the present invention, it is essential that the resin contains 20 to 80% of lactones. If the content of the lactone is less than 20%, the water resistance and low-temperature characteristics of the urethane resin synthesized from the polyester polyol deteriorate. On the other hand, if it is more than 80%, the melting point of the polyester polyol becomes 25 ° C. or more due to the crystallinity of the lactones, which is not preferable.

The hydroxyl value of the polyester polyol resin of the present invention is from 10 to 1000 KOH mg / g, preferably from 20 to 600 KOH mg / g. Having a hydroxyl value within this range is convenient for application to applications such as polyurethane elastomers.

Next, a method for synthesizing the polyester polyol resin will be described.

In the most basic method of synthesis, first of all, a polyhydric alcohol and glutaric acid or glutaric anhydride, or an ester of glutaric acid with a low molecular weight alcohol (for example, dimethyl glutarate) or another carboxylic acid (anhydride) (Ester with low molecular alcohol) Polyester as a raw material is synthesized by a dehydration or dealcoholization reaction. Then, lactones are charged and subjected to ring-opening polymerization and transesterification to obtain polyhydric alcohol / glutaric acid + polybasic acid /
A random copolymer of lactones is synthesized.

At this time, it is essential that glutaric acid be contained as a carboxylic acid component in an amount of 100 to 30% by weight of the carboxylic acid component.

When the content of glutaric acid is less than 30% by weight, the water resistance and low-temperature characteristics of the urethane resin synthesized from the polyester polyol resin deteriorate.

In the synthesis of the polyester polyol resin of the present invention, lactones can be charged from the beginning and reacted in one step, but the reaction time tends to be longer than in the case of synthesis in two steps. In any case, the polyester polyol resin of polyhydric alcohol / glutaric acid + polybasic acid and lactones are sufficiently transesterified to obtain the desired polyester polyol resin having a low melting point. The reaction temperature is from 130 ° C. to 2
The temperature is 40 ° C, preferably 140 ° C to 230 ° C. In addition, during the reaction, by performing the reaction under a stream of an inert gas such as nitrogen gas, it is possible to suppress the oxidative deterioration of the polyester in the reaction process and further suppress the deterioration of the hue of the resin.

For the synthesis of the polyester polyol resin, an esterification catalyst can be used. Examples of the esterification catalyst include tin octylate, dibutyl tin oxide, dibutyl tin laurate, organotin compounds such as monobutyl tin hydroxybutyl oxide, stannous oxide,
Tin compounds such as stannous chloride, tetrabutyl titanate, tetraethyl titanate, tetrapropyl titanate and the like can be used.

In particular, titanium-based catalysts have a sufficient transesterification ability and are suitable for the synthesis of random copolymers. The amount of the catalyst used is 0.1 PPM to 1000 PPM, preferably 1 PPM to 100 PPM. The amount of catalyst is 10
If it exceeds 00 PPM, coloring of the resin becomes intense, which adversely affects the stability of the product.

Conversely, if the amount of the catalyst used is 1 PPM or less, the rate of ring-opening polymerization of lactones becomes extremely slow, which is not preferable.

The polyester polyol resin having a low melting point according to the present invention can be used as a raw material for various polyurethanes by reacting with a polyisocyanate and then with a polyhydric alcohol or a polyamine, or as a (meth) acrylic ester having a hydroxyl group. By reacting with the above, it can be used as a raw material of a liquid photocurable urethane (meth) acrylate. Further, it can be used as a softener component of a coating material or as a polyester polyol as a raw material for a coating resin.

[0022]

The polyester polyol resin of the present invention will be described below with reference to examples, but the present invention is not limited by these examples. In the examples, all parts indicate parts by weight.

Example 1 456 g of cyclohexanedimethanol was placed in a 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer.
Dupont DBE (Mixture of methyl glutarate / methyl adipate / methyl succinate = 66/17/17)
344 g, ε-caprolactone 200 g, 1% of TBT
After 0.5 g of a heptane solution was charged, the mixture was demethanol-condensed at 170 ° C. for 5 hours under a nitrogen stream, and then heated to 205 ° C. and reacted until the residual methyl ester became 7% or less. The resulting caprolactone-containing polyester polyol was liquid at room temperature and had an OH value of 123.6 KOHmg / g.

Example 2 239 g of cyclohexanedimethanol was placed in a 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer.
Dupont DBE (Mixture of methyl glutarate / methyl adipate / methyl succinate = 66/17/17)
361 g, ε-caprolactone 400 g, 1% of TBT
After 0.5 g of a heptane solution was charged, the mixture was demethanol-condensed at 170 ° C. for 5 hours under a nitrogen stream, and then heated to 205 ° C. and reacted until the residual methyl ester became 7% or less. The obtained caprolactone-containing polyester polyol resin was liquid at room temperature and had an OH value of 118.0 KOHmg / g.

Example 3 510 g of cyclohexanedimethanol was placed in a 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer.
Dupont DBE (Mixture of methyl glutarate / methyl adipate / methyl succinate = 66/17/17)
484 g, ε-caprolactone 200 g, 1% of TBT
After 0.5 g of a heptane solution was charged, the mixture was demethanol-condensed at 170 ° C. for 5 hours under a nitrogen stream, and then heated to 205 ° C. and reacted until the residual methyl ester became 7% or less. The resulting caprolactone-containing polyester polyol resin was liquid at room temperature and had an OH value of 59.2 KOHmg / g.

Example 4 390 g of cyclohexanedimethanol was placed in a 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer.
Dupont DBE (Mixture of methyl glutarate / methyl adipate / methyl succinate = 66/17/17)
351 g, ε-caprolactone 400 g, 1% of TBT
After 0.5 g of a heptane solution was charged, the mixture was demethanol-condensed at 170 ° C. for 5 hours under a nitrogen stream, and then heated to 205 ° C. and reacted until the residual methyl ester became 7% or less. The resulting caprolactone-containing polyester polyol resin was liquid at room temperature and had an OH value of 54.3 KOHmg / g.

Example 5 418 g of cyclohexanedimethanol was placed in a 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer.
Dupont DBE (Mixture of methyl glutarate / methyl adipate / methyl succinate = 66/17/17)
302 g, ε-caprolactone 1280 g, 1 of TBT
1 g of a 1% heptane solution was charged, and the mixture was demethanol-condensed at 170 ° C. for 5 hours under a nitrogen stream, and then heated to 205 ° C. and reacted until the residual methyl ester became 7% or less. The obtained caprolactone-containing polyester polyol resin was liquid at room temperature and had an OH value of 55.2 KOHmg / g.

Comparative Example 1 969 g of cyclohexanedimethanol was placed in a 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer.
837 g of adipic acid, 400 g of ε-caprolactone, T
1 g of a 1% heptane solution of BT is charged, and 1
After dehydration condensation at 70 ° C for 5 hours, the temperature was raised to 205 ° C and the acid value was 1
The reaction was carried out until the following. The resulting caprolactone-containing polyester polyol resin has an OH value of 53.4K.
It was OH mg / g, the acid value was 0.60 KOH mg / g, and was a solid having a melting point of 80 °.

Comparative Example 2 743 g of cyclohexanedimethanol was placed in a 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer.
607 g of adipic acid, 800 g of ε-caprolactone, T
1 g of a 1% heptane solution of BT is charged, and 1
After dehydration condensation at 70 ° C for 5 hours, the temperature was raised to 205 ° C and the acid value was 1
The reaction was carried out until the following. The resulting caprolactone-containing polyester polyol resin has an OH value of 57.2K.
It was OH mg / g, the acid value was 0.72 KOH mg / g, and was a solid having a melting point of 58 °.

Comparative Example 3 516 g of cyclohexanedimethanol was placed in a 2 L reactor equipped with a condenser, a nitrogen inlet tube, a stirrer, and a thermometer.
377 g of adipic acid, 400 g of ε-caprolactone, T
1 g of a 1% heptane solution of BT is charged, and 1
After dehydration condensation at 70 ° C for 5 hours, the temperature was raised to 205 ° C and the acid value was 1
The reaction was carried out until the following. The resulting caprolactone-containing polyester polyol resin has an OH value of 110.2.
KOHmg / g, acid value 0.24KOHmg / g,
It was a solid with a melting point of 50 degrees.

Table 1 also shows the component ratios and the properties of the obtained resins in each of the examples and comparative examples.

Table 1 Sample name Molecular weight Lactone content Main component appearance Color hue OH value Acid value Carboxylic acid component (%) (Content% in polymer) (APHA) Example 1 1000 20 Glutaric acid (22.7) Liquid 110 123.6 0.09 Example 2 1000 40 Glutaric acid (23.8) Liquid 120 118.0 0.13 Example 3 2000 20 Glutaric acid (31.9) Liquid 120 59.2 0.12 Example 4 2000 40 Glutaric acid ( 23.7) Liquid 110 54.3 0.03 Example 5 2000 70 Glutaric acid (19.9) Liquid 110 55.2 0.01 Comparative Example 1 2000 20 Adipic acid (41.9) Solid 120 53.4 0.60 Comparative Example 2 2000 40 Adipic acid (30.4) Solid 140 57.2 0.72 Comparative Example 3 1000 20 Adipic acid (18.9) Solid 45 110.2 0.24 As shown in Table 1 above, the caprolactone-containing polyester resin containing glutaric acid is liquid at normal temperature, whereas it is synthesized from adipic acid. Was a solid at room temperature. (Below)

Claims (2)

(57) [Claims] (1) cyclohexanedimethanol and glucan
Dicarboxylic acid containing 100 to 30% by weight of tar acid
Polyester polyols
The lactone content in the polyester resin is 20 to 80% by weight.
A polyester polyol resin having a melting point of 25 ° C. or lower obtained by reacting a lactone as described above . 2. The polyester polyol resin according to claim 1, wherein the lactone is ε-caprolactone.