JPH0543516A - New polyester diol - Google Patents

Abstract

PURPOSE:To provide a new polyester diol useful as a material for elastomer, paint, adhesive, elastic fiber, sealant, etc., required to have bio-degradability, exhibiting liquid state in spite of high molecular weight and having excellent bio-degradability, hydrophilic nature and compatibility. CONSTITUTION:A polyester diol derived from (A) polyoxyethylene glycolic acid of formula (n is integer of 2-70), (B) one or more kinds of polyalkylene glycols and, as necessary, (C) a hydroxy alkylene carboxylic acid or its lactone. The compound can be produced by the esterification reaction of the components A and B. Since the compound has oxyethylene group on the main chain, it has excellent hydrophilic nature and compatibility to isocyanate. The polymer is polymerized through ester bond and, accordingly, it has excellent bio- degradability and exhibits liquid state in spite of high molecular weight. Accordingly, it is useful as a raw material for various industrial products mentioned above to be applied to polyurethane, polyester, epoxy resin, etc.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel polyester diol. More specifically, it is a polyester diol having polyoxyethylene diglycolic acid as an acid component and having hydroxyl groups at both ends obtained by an esterification reaction with various glycols, polyurethane,
It is used as a raw material for various industrial products such as elastomers, paints, adhesives, elastic fibers, and sealants that are applied to polyester and epoxy resins, but it has good biodegradability and has a high molecular weight, yet it remains liquid. It is a very useful raw material.

[0002]

2. Description of the Related Art Polyols are polymers having two or more hydroxyl groups in the molecule, and polyether-based polyols and polyester-based polyols have been mainly used in various fields.

As the polyether-based polyol, polyethylene glycol, polypropylene glycol, poly (oxyethylene-oxypropylene) glycol which is a copolymer of ethylene oxide and propylene oxide, and the like are used in terms of activity of terminal hydroxyl groups and hydrophilicity. Used in lubricants, surfactants, urethanes, pharmaceuticals, cosmetics, etc.

However, development of biodegradable plastics has been desired due to recent global environmental problems and measures for processing plastic wastes. Regarding this, there is a problem that the polyether-based polyol has low biodegradability in view of reported examples of mold growth and degradability by enzymes. In mold growth tests on polyurethanes, ester type polyurethanes were reported to have better decomposability than ether type polyurethanes. Furthermore, among polyester type polyurethanes, synthetic polymers were found to be less biodegradable as aromatic components increased. In this case, it can be said that the polymer which can be said to be biodegradable has a practical upper limit to the aliphatic polyester.

Examples of aliphatic polyester-based polyols having good biodegradability include condensation-type polyester polyols such as ethylene adipate and butylene adipate, and lactone-based polyester polyols obtained by ring-opening polymerization of ε-caprolactone. At present, it is inferior to polyether-based polyols in terms of properties and compatibility with isocyanates.

Further, the properties of the polyester-based polyol vary from liquid to solid, but generally, when the molecular weight is as low as several hundreds, it is liquid, and when the molecular weight is higher than that, it becomes a highly viscous substance or solid. High-viscosity materials and solid materials can be processed by pressure molding or high-pressure injection molding, but pressure molding is inefficient, and injection molding requires high temperature and high pressure, and equipment is expensive. .. Liquid materials can be cast and low-pressure injection molded, and composite materials can be easily impregnated. From this viewpoint, it is expected that polymer materials that can be molded, processed and used in liquid form will become more important in the future.

[0007]

DISCLOSURE OF THE INVENTION The present invention is intended to obtain a polyol that solves the above-mentioned problems of conventional polyether polyols and polyester polyols, and is excellent in biodegradability, hydrophilicity and compatibility. It is intended to provide an excellent liquid polyol.

[0008]

The present invention is a polyester diol having a hydroxyl group at the terminal obtained by an esterification reaction with various glycols using polyoxyethylene diglycolic acid as an acid component, which has an oxy group of the main chain. The ethylene group is excellent in hydrophilicity and compatibility, and by providing an ester bond, it has excellent biodegradability, and provides a polyol which is a high molecular weight and is kept in a liquid state.

The polyoxyethylene diglycolic acid used in the present invention is liquid, and a commercially available product can be used as the dicarboxylic acid obtained by oxidizing the terminal hydroxyl group of polyethylene glycol.

As the polyalkylene glycol to be reacted with the above dicarboxylic acid, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 1,4-butanediol, 1,3-butanediol, 2 One or a mixture of two or more diols such as 1,3-butanediol, 1,5-pentanediol and 1,6-hexanediol is used. At this time, 2
Mixing and using one or more kinds of polyalkylene glycol is useful for preventing crystallization due to the regularity of molecules and for obtaining a high-molecular liquid polymer. The term "more glycol" in claim 1 represents this.

In addition to the above-mentioned dicarboxylic acids and polyalkylene glycols, glycolic acid, hydroxycarboxylic acids such as lactic acid, lactones such as ε-caprolactone and γ-butyrolactone, and cyclic carbonates such as ethylene carbonate can be used for chain extension. You can also

The reaction between the above dicarboxylic acid and glycol is
It is carried out by a usual esterification reaction. That is, it is achieved by heating the dicarboxylic acid and glycol in a solvent that is easily separated from water, such as ethyl acetate, toluene, and xylene, and removing the condensed water produced by azeotroping with the solvent. The reaction temperature depends on the solvent used, but is from room temperature to 160.
C., preferably in the range of 80 to 150.degree.

Since the acid component also functions as an esterification catalyst, the glycol component used has a high boiling point, and the esterification can be carried out at a high temperature, the reaction proceeds sufficiently even without using a catalyst. Can be added to accelerate the esterification reaction. As the catalyst used in this case,
Mineral acids such as sulfuric acid and hydrochloric acid, organic acids such as paratoluene sulfonic acid, Lewis acids such as boron fluoride etherate, organic titanium compounds such as tetrabutyl titanate and tetrapropyl titanate, tin octylate, dibutyltin oxide, dibutyltin laurate Organic tin compounds such as, stannous chloride, stannous halides such as stannous bromide, activated clay, acidic ion exchange resins, etc. can be used.

The molecular weight of the polyester diol of the present invention can be adjusted by determining the molar ratio of dicarboxylic acid and glycol, but it is necessary to always use an excess amount of glycol because both ends have hydroxyl groups. The amount of polyoxyethylene dicarboxylic acid and glycol used is O
The ratio of H / COOH is 1.1 or more, preferably 1.2 to
The range is 2.

[0015]

EXAMPLES Next, the present invention will be specifically described by way of examples. Example 1 Polyoxyethylene diglycolic acid 160 in a 500 ml four-necked flask equipped with a Dean-Stark water separator.
g (manufactured by Wako Pure Chemical Industries, molecular weight 400-500), 54.4 g of diethylene glycol and 100 ml of xylene were added, and the mixture was heated and dehydrated for 10 hours in a nitrogen stream. The solvent is distilled off under reduced pressure,
Weight average molecular weight 1500, hydroxyl value 92, viscosity 2300
A polyester diol of cps (25 ° C.) was obtained. Example 2 94 g polyoxyethylene diglycolic acid in a 300 ml four-necked flask equipped with a Dean-Stark water separator.
(Wako Pure Chemical Industries, Ltd., molecular weight 400-500), 15 g of propylene glycol, 17 g of triethylene glycol and 100 ml of xylene were added and the mixture was heated and dehydrated for 10 hours in a nitrogen stream. The solvent was distilled off under reduced pressure to obtain a polyester diol having a weight average molecular weight of 1700, a hydroxyl value of 90 and a viscosity of 2600 cps (25 ° C.). Example 3 70 g of polyoxyethylene diglycolic acid in a 300 ml four-necked flask equipped with a Dean-Stark water separator.
(Wako Pure Chemical Industries, molecular weight 400-500), diethylene glycol 24 g, Amberlyst-15.4 g (organo, strong acid cation exchange resin), and 70 ml of isopropyl ether were added, and the mixture was heated and dehydrated for 12 hours in a nitrogen stream.
After separating the ion exchange resin by filtration, the solvent was distilled off under reduced pressure to give a weight average molecular weight of 2500, a hydroxyl value of 48 and a viscosity of 3500 cps.
(25 ° C.) polyester diol was obtained. Example 4 Polyoxyethylene diglycolic acid was added to a 300 ml four-necked flask equipped with a Dean-Stark water separator.
8 g (manufactured by Wako Pure Chemical Industries, molecular weight 400-500), diethylene glycol 24 g, glycolic acid 15.2 g, and toluene 50 ml were added, and the mixture was heated and dehydrated for 12 hours in a nitrogen stream.
The solvent was distilled off under reduced pressure to obtain a polyester diol having a weight average molecular weight of 1500, a hydroxyl value of 105, and a viscosity of 1400 cps (25 ° C.). Example 5 A 300 ml four-necked flask equipped with a Dean-Stark water separator was charged with 93.
6 g (Wako Pure Chemical Industries, molecular weight 400-500), tetraethylene glycol 38.8 g, γ-butyrolactone 1
7.2 g, activated clay 1.7 g (manufactured by Wako Pure Chemical Industries, Ltd.) and xylene 100 ml were added, and the mixture was heated and dehydrated in a nitrogen stream for 12 hours.
After filtering off the activated clay, the solvent was distilled off under reduced pressure to obtain a weight average molecular weight of 3300, a hydroxyl value of 36, and a viscosity of 4400 cps (25
C) polyester diol was obtained.

[0016]

EFFECT OF THE INVENTION The polyester diol of the present invention is excellent in hydrophilicity and compatibility with isocyanate due to having an oxyethylene group in the main chain, and is biodegradable because it is a polymer polymerized by ester bond. It is a liquid polymer with excellent properties and can be widely used in materials such as elastomers, paints, adhesives, elastic fibers and sealants, which require biodegradability.

Claims (2)

[Claims] [Claim 1] (wherein, n an integer of 2-70) the following general formula _{HOOC-CH 2 -O- (CH 2} CH 2 O) n -CH 2 COOH and polyoxyethylene diglycolic acid represented by poly 1 of alkylene glycol
Polyester diol obtained from one or more glycols. 2. A polyester diol obtained from the polyoxyethylene glycol acid, polyalkylene glycol and hydroxyalkylene carboxylic acid or lactone thereof.