JPH02175721A - Polycarbonate diol - Google Patents

Abstract

PURPOSE:To provide a polycarbonate diol which can give a polyurethane having a good balance among low-temperature properties, strengths, wet-heat resistance, etc., by reacting a diol component of a specified composition comprising a polyether polyol and a polyalcohol with a carbonate component. CONSTITUTION:A carbonate component selected from among a compound which requires dehydrochlorination (e.g. phosgene), an alkylene carbonate (e.g. ethylene carbonate), a diallyl carbonate and a dialkyl carbonate is prepared. Separately, 20-80wt.% polyether polyol of an MW of 300-2000 (e.g. polytetramethylene glycol) is mixed with 80-20wt.% 20C or lower polyalcohol (e.g. 1,2-propanediol). The obtained diol compound is reacted with the above carbonate component to produce a polycarbonate diol.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to polycarbonate diol compounds.

[Prior Art] Polyurethane resins are used in many fields such as foams, adhesives, fibers such as elastomer spandex, and paints, and their main raw materials are polyisocyanates and polyols.

Polyols include polyether polyols such as polypropylene glycol and polytetramethylene glycol, polyester polyols derived from dicarboxylic acids such as adipic acid and polyhydric alcohols, and polyols obtained by reacting lactones with alcohol. Polylactone polyols and the like are used, and are used for various purposes depending on the required performance.

However, since polyether polyol has ether bonds, urethane resins produced using it have the disadvantage of poor heat resistance and weather resistance.

On the other hand, since polyester polyols and polylactone polyols have ester bonds, urethane resins produced using them have the disadvantage of poor water resistance.

In order to obtain a new urethane resin that overcomes these drawbacks, it has been proposed to use a polyol having a carbonate bond in its molecular structure as a raw material.

Polycarbonate polyols that are currently most widely used, that is, polyols that have carbonate bonds in their molecular structure, have 1.
It has θ-hexanediol as its basic skeleton.

I HO (CH2) 6[0CO- = (CH2)6] nOH (1) Polycarbonate diol having a 1,6-hexanediol structure in its basic skeleton is a polyurethane resin obtained using it that is mechanically resistant. It has a very good balance of strength, heat resistance, moisture resistance, etc., and also has the advantage of being easily manufactured industrially.

[Problems to be Solved by the Invention] However, since the polycarbonate diol having this 1,6-hexanediol structure in its basic skeleton has crystallinity, the polyurethane resin obtained using it is It has the disadvantage of poor low-temperature properties.

On the other hand, polyetherol, which has excellent low-temperature properties, has the problem of lacking heat resistance.

The present inventors have investigated how to solve these problems and develop a polycarbonate diol that can synthesize polyurethane that has excellent mechanical strength, moisture and heat resistance, and improved low-temperature properties, and as a result, they have arrived at the present invention. .

[Configuration of the Invention] That is, the present invention provides a polycarbonate diol obtained by reacting a diol compound with one compound selected from the group consisting of a compound requiring a dehydrochlorination step, an alkylene carbonate, a diaryl carbonate, and a dialkyl carbonate. , the diol compound used is ■ polyether polyol 2 with a molecular weight of 300 to 2000
0 to 80% by weight ■ A polycarbonate diol characterized by being composed of a mixture of one type selected from polyhydric alcohols having 20 or less carbon atoms at a ratio of 80 to 20% by weight.

Among the compounds that are one component of the polycarbonate diol in the present invention, compounds that require a dehydrochlorination step include phosgene and bischloroformate.

Examples of the alkylene carbonate include ethylene carbonate, 1,2-propylene carbonate, and 1,2-butylene carbonate.

Examples of diaryl carbonates include diphenyl carbonate and dinaphthyl carbonate.

Examples of the dialkyl carbonate include dimethyl carbonate and diethyl carbonate. these are,
Any of these can be reacted with a diol compound described below to form a polycarbonate diol by a known method.

In the present invention, the polyether polyol (2) includes polypropylene glycol obtained by ring-opening polymerization of propylene oxide with various polyhydric alcohols such as diethylene glycol, triethylene glycol, tetraethylene glycol, tripropylene glycol, and polypropylene glycol, and furthermore, ethylene oxide and propylene glycol. Examples include polyether polyols copolymerized with oxides.

Furthermore, polytetramethylene glycol, which is a ring-opened polymer of tetrahydrofuran, can also be used.

The molecular weight of these polyether polyols is 300-2
Preferably, it is 000.

If the molecular weight is less than 300, the properties of the polyether polyol will not be fully exhibited and the low temperature properties of the resulting carbonate diol will not be improved.

Further, when a polyether bodiol having a molecular weight exceeding 2000 is used, the molecular weight of the carbonate diol to be obtained is at least 4000 to 5000 in order to obtain the characteristics possessed by carbonate diol.

A polyol having such a molecular weight is essentially meaningless as a raw material for urethane.

These polyether polyols may be used alone or in combination of two or more.

20 to 80% by weight of the above ■ polyether polyol■
At least one type selected from polyhydric alcohols having 20 or less carbon atoms is charged in a proportion of 80 to 20% by weight and reacted.

The following polyhydric alcohols having 20 or less carbon atoms can be used.

Ethylene glycol, 1,2-propanediol, 1.
3-butanediol, 2-methyl-1°3-propanediol, neopentyl glycol, hydroxyl pivalate of neopentyl glycol, 2-methylbentanediol, 3-methylbentanediol, 2,2
．． 4-trimethyl-1,6-hexanediol, 3.3
These include 5-trimethyl-1,6-hexanediol and 2,3°5-trimethylbentanediol.

When the polyether polyol is less than 20% by weight, the resulting polycarbonate diol has poor low-temperature properties, and the desired performance of the present invention cannot be obtained.

Furthermore, if the polyether polyol (■) exceeds 80% by weight, there is no point in using it together with (■) a polyhydric alcohol having 20 or less carbon atoms, and the characteristics of the carbonate bond are lost, so in the polyurethane synthesized using this, Mechanical strength etc. cannot be obtained.

As the dialkyl carbonate used in the present invention, dimethyl carbonate and diethyl carbonate are suitable.

Even if a polycarbonate diol having more than 20 carbon atoms is used, an industrially superior and preferred polycarbonate diol cannot be obtained.

The general formula for the reaction for obtaining the polycarbonate diol of the present invention is as follows.

n R-OCO-R+ (n +1) HO-R' -
OR↓ HO-R(-0CO-R') -0H+2nROH
(R is an alkyl group or chlorine, R' is a polyether polyol or 1,6-hexanediol residue) At this time, the small (both two types of diol compounds) used as raw materials are randomly assembled in the molecule by carbonate bonds. It's crowded.

If one is HO-R-0H1 and the other is HO-R2-OH, -0-Co-R1-0-C-0- and -0CO-R
2-0CO- are randomly present in the molecule.

The random bonding of polyether chains through carbonate bonds destroys crystallinity, and the resulting carbonate diol exhibits low-temperature properties.

Next, ■ Polyether polyol 2 with a molecular weight of 300 to 2000
0 to 80% by weight ■ At least one type selected from polyhydric alcohols having 20 or less carbon atoms is reacted with 80 to 20% by weight of aliphatic diol, which is a mixture of both.For dialkyl carbonate as another raw material. We will explain in detail the situation, including the reaction procedure, in case of a reaction.

A catalyst commonly used in transesterification can be used in the reaction.

For example, lithium, sodium, potassium, rubidium,
Cesium, magnesium, calcium, strontium, barium, zinc, aluminum, titanium, cobalt,
There are metals such as germanium, tin, lead, antimony, arsenic and cerium and their alkoxides.

Examples of other suitable catalysts include alkali and alkaline earth metal carbonates, zinc borate, zinc oxide, lead silicate, lead arsenate, lead carbonate, antimony trioxide, germanium dioxide, cerium trioxide, and aluminum isopropoxide.

Particularly useful and preferred catalysts are organometallic compounds such as metal salts of organic acids such as magnesium, calcium, cerium, barium, zinc, tin, titanium, and the like.

The amount of catalyst used is 0.0001% to 1% of the total weight of starting materials.
．． 0% is appropriate.

Preferably it is 0001 to 0.2%.

The reaction temperature is preferably about 80°C to 220°C.

At the beginning of the reaction, the reaction is carried out at a temperature near the boiling point of the dialkyl carbonate, and as the reaction progresses, the temperature is gradually raised to further advance the reaction.

The device capable of separating the generated diol compound and the raw material dialkyl carbonate is usually a reactor with a distillation column.
The reaction is carried out while the dialkyl carbonate is refluxed, and the alcohol produced as the reaction progresses is distilled off.

In this case, some of the dialkyl carbonate is azeotroped and dissipated together with the distilled alcohol.

It is best to take this amount of dissipation into account when weighing and preparing raw materials.

According to the above reaction formula, the theoretical molar ratio is (n+1) moles of diol compound to n moles of dialkyl carbonate, but in reality, the molar ratio of dialkyl carbonate/diol compound is set to 1°1 to 1.3 of the theoretical molar ratio. It is better to do so.

The reaction can be carried out at normal pressure, but in the latter half of the reaction it can be carried out under reduced pressure, for example at lmmHg to 200mmHg, to accelerate the progress of the reaction.

The molecular weight of the polycarbonate diol in the present invention is
It can be adjusted by changing the reaction molar ratio between the raw material diol compound and dialkyl carbonate, dialkylene carbonate, etc.

That is, the molecular weight can be controlled by adjusting n of the ablation.

In addition, 1) the polycarbonate diol of the present invention is hydrolyzed and the decomposition product is analyzed by gas chromatography or NMR; 20 to 80% by weight of a polyether polyol with a molecular f of 1300 to 2000; and a polyhydric alcohol with a carbon number of 20 or less. It can be confirmed that 80 to 20% by weight of at least one selected from the following is used in combination.

[Effect of the invention] The urethane resin obtained using the thus obtained polycarbonate diol as a raw material has low-temperature properties, mechanical strength,
It has well-balanced properties such as moisture and heat resistance, and can be widely used in various industrial applications such as elastomer 1 adhesive, magnetic tape binder, and spandex. The present invention will be explained below with reference to Examples.

[Example-1] 620 g of dimethyl carbonate (6,8
9 mol), 740 g' of 1,6-hexanediol (6,
27 mol), 640 g of polytetramethylene glycol (PTMG800 manufactured by Mitsubishi Kasei Corporation) with a molecular weight of 830 (0,
77 mol), tetrabutyl titanate 0.3 as catalyst
0 g was charged, and the reaction was carried out under normal pressure with boiling dimethyl carbonate, and methanol was distilled off.

The temperature of the reaction vessel gradually increased and reached 200°C, and when almost no methanol was distilled out, a vacuum operation was started, and unreacted substances were distilled off under reduced pressure to a final volume of 20 mm and 11 g to obtain a reaction product. .

The obtained polycarbonate diol had an OH value of 55.2.
It was a paste-like substance with a melting point of 30°C.

[Example-2] Instead of 640 g (0°77 mol) of polytetramethylene glycol (PTMG800, manufactured by Mitsubishi Kasei) with a molecular weight of 1830, 640.
The following results were obtained by carrying out the same procedure as in Example 1 except that g (0,853 mol) was used.

The obtained polycarbonate diol was a viscous liquid with an OHH value of 571.

[Example-3] The following results were obtained by carrying out the same procedure as in Example 1 except that 740 g (6.27 moles) of 3-methylbentanediol was used instead of 1,6-hexanediol.

The obtained polycarbonate diol was a viscous liquid with an OHH value of 552.

[Example 4] The following results were obtained by carrying out the same procedure as in Example 1 except that 990 g (11 mol) of 1.4-butanediol was used instead of 1.6-hexanediol.

The obtained polycarbonate diol was a paste-like material with an OHH value of 565.

[Example-5] The same procedure as in Example 1 was carried out except that 3-methylbentanediol was mixed at a molar ratio of 2/1 instead of 1.6-hexanediol alone, and the following results were obtained. I got it.

The obtained polycarbonate diol was a viscous liquid with an OHH value of 558.

[Example-6] Polytetramethylene glycol with a molecular weight of 650 (PTMG65, manufactured by Mitsubishi Chemical Corporation) was used instead of polytetramethylene glycol (PTMG800, manufactured by Mitsubishi Chemical Corporation) with a molecular weight of 830.
Example 1 was repeated except that 640 g (0.98 mol) of 0) was used, and the following results were obtained.

The obtained polycarbonate diol was a viscous liquid with an OH value of 57.2.

[Comparative Example-1] Using the same apparatus as in Example-1, 1 was used as a diol compound.
, 6-hexanediol was used in the same manner to obtain polycarbonate diol.

[Application Example-1] Using the polycarbonate diol obtained in Examples-1 to 6 and Comparative Example-1 as raw materials, a urethane solution was synthesized under the reaction conditions shown below, and a film thickness of 150 μm was obtained from this urethane solution.
A urethane film was prepared and its physical properties were evaluated.

[Urethane solution reaction conditions]

(1) Compound polyol 100 parts 1, 48G 8.3 parts MDI 35.6 parts Solvent (DMF) 267.3 parts Note) Polyol (Mv2000) / 1.4 B G
/ M D lNC010H-1,03 1,48G/Polyol-2,0 (2) 100 parts of Kutsukingeskeshinyl polyol, 8.3 parts of 1.48G.

144 parts of the solvent was charged into a reactor and heated to 60°C.

Next, 35.6 parts of MDI was added and the temperature was further increased.

Once the temperature inside the reactor reaches 80°C, maintain that temperature for several hours.

Thereafter, heat is removed until the temperature in one reactor reaches 60°C.

When the temperature reached 60°C, 123.3 parts of solvent was added and the mixture was aged at that temperature.

(3) Properties of urethane solution NV (%) - 35 VIS (cp/25°C) - 60,000 to 80,000 Solvent - DMF (4) Preparation of film Coat the polyurethane solution on release paper and force dry.

Finished film thickness (μ) -150 (5) Measurement of physical properties JISB dumbbell punching 4ki [Standard machine] Shimadzu Autograph The results are shown in Table-1.

As shown in Table 1, the urethane foam and ilm using the carbonate diol of the present invention have excellent low-temperature properties.

Claims (1)

[Claims] A polycarbonate diol obtained by reacting a diol compound with one compound selected from the group consisting of alkylene carbonate, diaryl carbonate, and dialkyl carbonate, which requires a dehydrochlorination step, in which the diol compound used is (1) 20 to 80% by weight of polyether polyol with a molecular weight of 300 to 2,000 (2) Consisting of a mixture of at least one type selected from polyhydric alcohols having 20 or less carbon atoms at a ratio of 80 to 20% by weight A polycarbonate diol characterized by: