JPH06100674A - Polyester polyol - Google Patents

Abstract

PURPOSE:To provide a polyester polyol which has a specified molecular structure. quickly reacts with an isocyanate compd., and is useful as a material for producing a polyurethane excellent in water resistance, clarity, etc. CONSTITUTION:A polyester polyol has a number-average mol.wt. of 600-6,000 and a molecular structure represented by the formula wherein R1 is H or alkyl; R2 is alkyl; R3 is alkylene, alkenylene, or phenylene; R4 is alkylene; n is an integer of 1-40; and m and p are each an integer of 1-4.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to polyester polyols. The polyester polyol is useful as a raw material for polyurethane.

[0002]

BACKGROUND OF THE INVENTION Polyester polyols, which are raw materials for polyurethane, are dicarboxylic acids (adipic acid, sebacic acid, etc.) and glycols (ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, etc.). Obtained by condensation with. However, polyurethanes produced using these polyester polyols have inferior water resistance and are susceptible to hydrolysis.

As a polyester polyol for producing a polyurethane having good water resistance, 2-n-butyl-
A polyester polyol obtained by condensation of 2-ethyl-1,3-propanediol and a polycarboxylic acid is known (Japanese Patent Laid-Open No. 60-229918). However, the reaction rate of the polyester polyol and isocyanate is slow, and it is difficult to produce a polyurethane excellent in transparency other than water resistance and the like even if the polyester polyol is used.

An object of the present invention is to provide a polyester polyol which is a raw material for producing a polyurethane which has a fast reaction rate with isocyanate and is excellent in water resistance and transparency.

[0005]

The present invention provides a compound of formula (I)

[0006]

[Chemical 2]

(Wherein R ₁ represents hydrogen or alkyl,
R ₂ represents alkyl, R ₃ represents alkylene, alkenylene or phenylene, R ₄ represents alkylene, n
Represents an integer of 1 to 40 and m and p represent an integer of 1 to 4) and has a number average molecular weight of 600 to 6,000. In the definition of the formula (I), the alkyl includes alkyl having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl and hexyl, and the alkylene of R ₃ has 1 to 9 carbon atoms.
Of alkylene, for example, methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, and the like, and the alkylene of R ₄ has 3 to 5 carbon atoms.
And trimethylene, tetramethylene, pentamethylene and the like, and examples of the alkenylene include alkenylene having 2 to 4 carbon atoms, such as vinylene and propenylene.

Next, a method for producing the compound (I) will be described. Reaction formula

[0009]

[Chemical 3]

Compound (IV) is the same as compound (II) in the range of 1.01 to 1.2.
It is obtained by reacting with the compound (III) in a molar amount at 180 to 220 ° C. for 3 to 10 hours. Compound (IV) is usually used in the next reaction without isolation. Examples of the compound (II) include saturated or unsaturated aliphatic dicarboxylic acids having 1 to 9 carbon atoms or aromatic dicarboxylic acids such as malonic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, orthophthalic acid. Acid, isophthalic acid, terephthalic acid and the like can be mentioned.

Examples of the compound (III) include 2,2-diethyl-1,3-propane glycol, 2-ethyl-2-propyl-1,3-propane glycol and 2-ethyl-2-.
Butyl-1,3-propane glycol, neopentyl glycol, 2-methyl-2-butyl-1,3-propane glycol and 2-hexyl-1,3-propane glycol may be mentioned.

The compound (I) is prepared by mixing the compound (IV) with 2 to 8 times mol of the compound (V) in the presence of a catalyst at 170 to 220 ° C.
Obtained by reacting for ~ 5 hours. Compound (V)
Examples thereof include aliphatic lactones having 4 to 6 carbon atoms, such as butyrolactone, δ-valerolactone and ε-caprolactone. Examples of the catalyst include tetrabutyl titanate and tin octylate. The compound (I) obtained has a number average molecular weight of 600 to 6,000.

Representative examples of the compound (I) are shown below. still,
Compounds 1, 2, 3 and 4 correspond to the compounds obtained in Examples 1, 2, 3 and 4. Compound 1

[0014]

[Chemical 4]

Compound 2

[0016]

[Chemical 5]

Compound 3

[0018]

[Chemical 6]

Compound 4

[0020]

[Chemical 7]

[0021]

EXAMPLES Examples and comparative examples will be shown below. Example 1 A reactor equipped with a stirrer, a reflux condenser, and a nitrogen inlet tube to withstand reduced pressure was charged with 2-n-butyl-2-ethyl-1,3-.
523.9 kg of propanediol and 404.7 kg of adipic acid were charged and reacted at 200 ° C while stirring. After reacting for about 6 hours, the acid value reached 0, so ε-caprolactone 1
Add 71.2 kg and 3.0 kg of tetrabutyl titanate, and add 200
A polyester polyol was obtained by reacting at 3 ° C. for 3 hours.
The produced polyester polyol is liquid at room temperature and has a viscosity ^{* 1.}
It was 240 poise, acid value ^{* 2} 0.0, hydroxyl value ^{* 3} 56.1, and number average molecular weight ^{* 4} 2,000. The target degree of terminal modification is
It was calculated from the peak area ratio of hydrogen (underline) attached to α carbon in a 400 MHz hydrogen nuclear magnetic resonance spectrum. All of the terminal groups of the polyester polyol obtained here were derived from caprolactone groups.

--CH ₂ --CH ₂ --OH (shift from tetramethylsilane: about 4.40 ppm) * 1 Viscosity; Measurement conditions B type viscometer 25 ° C. Measured viscosity up to 400 poise Rotor No. 6 rpm 2
Rotor No.6 Rotation speed 10rp
m * 2 Acid value; JIS K 1557 * 3 Hydroxyl value: JIS K 1557 * 4

[0023]

[Equation 1]

Example 2 In Example 1, instead of ε-caprolactone, δ-
A polyester polyol was obtained in the same manner as in Example 1 except that 100.3 kg of valerolactone was used. The produced polyester polyol is liquid at room temperature, viscosity is 250 poise, acid value is 0.0,
The hydroxyl value was 60.4 and the number average molecular weight was 1,860. The rate of terminal modification calculated by the same method as in Example 1 was about 100%.

Example 3 In Example 1, 2-n-butyl-2-ethyl-1,3
2,2-diethyl-1,3-propanediol instead of propanediol, adipic acid and ε-caprolactone
500.0 kg, adipic acid 502.5 kg and ε-caprolactone
A polyester polyol was obtained in the same manner as in Example 1 except that 117.6 kg was used. The polyester polyol produced is liquid at room temperature, viscosity 580 poise, acid value 0.0, hydroxyl value
It was 38.7 and the number average molecular weight was 2,900. The rate of terminal modification calculated by the same method as in Example 1 was about 100%.

Example 4 In Example 1, 2-n-butyl-2-ethyl-1,3
-N-hexyl-1,3-propane glycol 487.8 kg, dimethyl terephthalate 494.0 kg and ε-in place of propanediol, adipic acid and ε-caprolactone
A polyester polyol was obtained in the same manner as in Example 1 except that 171.2 kg of caprolactone was used. The polyester polyol produced is liquid at room temperature, with a viscosity of 600 poise and an acid value.
The value was 0.0, the hydroxyl value was 56.7, and the number average molecular weight was 1,980. The ratio of terminal modification calculated by the same method as in Example 1 was about 99%.
Met.

Comparative Example 1 In a reactor equipped with a stirrer, a reflux condenser, and a nitrogen introduction tube, which can withstand reduced pressure, 2-n-butyl-2-ethyl-1,3-
613.5 kg of propanediol and 486.4 kg of adipic acid were charged and reacted at 200 ° C with stirring. After about 5 hours, the reaction rate remarkably decreased. Therefore, the reaction was continued while reducing the pressure to about 30 Tricheri, the reaction was terminated when the acid value reached 0.6, and a polyester polyol represented by the following formula was obtained. The produced polyester polyol is liquid at room temperature, viscosity is 180 poise, hydroxyl value is 56.8, number average molecular weight is 19
It was 55.

[0028]

[Chemical 8]

Comparative Example 2: Reactivity of Polyester Polyol The reaction rates of the polyester polyols obtained in Examples 1 to 4 and the polyester polyol obtained in Comparative Example 1 with diisocyanate were measured. The reaction rate was measured as follows. The polyester polyol was dissolved in dimethylformamide, heated to a predetermined temperature shown in Table 1, and 4,4′-diphenylmethane diisocyanate was added and reacted. Samples were taken 2, 4 and 8 minutes after the start of the reaction, and the reaction rate was determined from the amount of 4,4'-diphenylmethane diisocyanate remaining, and the reaction rate constant (mol / l / min) at the initial stage of the reaction was calculated. (Reaction conditions) Concentration of polyester polyol: 0.15 mol / l Molar ratio of polyester polyol and 4,4'-diphenylmethane diisocyanate = 1: 1 Reaction temperature: 160, 180, 200 ° C Reaction pressure: 50 kg / cm ² The results are shown in Table 1.

[0030]

[Table 1]

As is apparent from the table, the polyester polyols of Examples 1 to 4 with the terminal groups modified have improved reactivity with respect to diisocyanate as compared with the polyester polyol of Comparative Example 1 in which the terminal groups have not been modified. Further, the polyester polyols of Examples 1 to 4 have little change in reaction rate with respect to temperature change, and it is possible to produce a polyurethane having a stable composition even if the polymerization reaction temperature of the polyester polyol and diisocyanate fluctuates.

Comparative Example 3: Polyurethane Production Method 202.0 kg of the polyester polyol obtained in Example 1
After thoroughly mixing and degassing 20.0 kg of 1,4-butane glycol at 60 ° C, it was stored in a storage tank 1 kept at 60 ° C (raw material A). On the other hand, 80.0 kg of 4,4′-diphenylmethane diisocyanate kept at 45 ° C. was stored in the storage tank 2 (raw material B). Raw material A from each storage tank using a metering pump
Number of moles of hydroxyl group / number of moles of isocyanate group of raw material B = 1.
Supply to the twin-screw reactive extruder in the range of 000 / 0.999-0.996,
A polyurethane was continuously produced at about 230 ° C. and a residence time (reaction time) of about 110 seconds. 80% of the generated polyurethane
It was aged at ℃ for 24 hours. The obtained polyurethane was transparent, had a melt flow index of 20.0 (190 ° C / 8,700g) and a hardness of shore 70A, and was excellent in water resistance, low temperature flexibility and the like.

As a control, 199.9 kg of the polyester polyol obtained in Comparative Example 1 and 20.0 of 1,4-butane glycol were used.
kg and 4,4'-diphenylmethane diisocyanate 80.0
Polyurethane was obtained in the same manner as above using kg. The resulting polyurethane was opaque (milky white), had a melt flow index of 46.0 (190 ° C / 8,700g) and a hardness of Shore 82A, and was unsatisfactory in water resistance and low-temperature flexibility.

[0034]

The polyester polyol of the present invention has excellent reactivity with isocyanate, and the polyurethane obtained by using the polyester polyol has excellent transparency, water resistance and low temperature flexibility.

Claims (1)

[Claims] 1. Formula (I): (In the formula, R ₁ represents hydrogen or alkyl, R ₂ represents alkyl, R ₃ represents alkylene, alkenylene or phenylene, R ₄ represents alkylene, n represents an integer of 1 to 40, and m and p represents an integer of 1 to 4) and a polyester polyol having a number average molecular weight of 600 to 6,000.