JPH0627083B2 - Propanediol and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention has high performance as a synthetic raw material for polyurethane resins, polyester resins, plasticizers, cosmetics, etc. and a heat medium, a reaction solvent, a vehicle for forming a conductor film, etc. 2-pentyl-2-propyl-, which is easy to handle because it is a liquid
The present invention relates to 1,3-propanediol and a method for producing the same.

(Prior Art) Generally, it is already known that glycols having no hydrogen atom in β-carbon atom, for example, polyester resin synthesized from neopentyl glycol as a raw material is excellent in heat resistance, water resistance, alkali resistance, acid resistance and the like. Are known.
Especially, the ester of neopentyl glycol is stable to alkali and acid and is difficult to be hydrolyzed because the two methyl groups of β-carbon atom of neopentyl glycol prevent attack of hydroxide ion and hydrogen ion. It is believed that. It is also considered that, in terms of heat resistance, the carbon atom at the β-position does not have a hydrogen atom, so that a six-membered ring cannot be formed as a transition state during the thermal decomposition process. However, recently, the demand for higher functionality in various applications has further increased, and raw material diols having higher functionality are required.

The 2,2-dialkyl-substituted-1,3-propanediol has a dialkyl group of dimethyl (neopentyl glycol, sometimes abbreviated as NPG hereinafter) and diethyl (2,2-diethyl-1,3-propane). Diol,
Hereinafter, they are sometimes abbreviated as DMP), and those of ethyl and butyl (2-butyl-2-ethyl-1,3-propanediol, hereinafter sometimes abbreviated as DMH) are known. Further, Japanese Patent Publication No. 39-1545 is known as a diol having an alkyl group of 1 to 6 carbon atoms. A similar statement
41-8769, JP-A-47-10223, JP-B-51-1
There are 8928 and JP-A-57-53421.

(Problems to be Solved by the Invention) Although Japanese Patent Publication No. 39-1545 is known as a diol having an alkyl group of 1 to 6 carbon atoms, the compound closest to the detailed description is 2,2- Dipropyl-1,3
-Propanediol, 2-methyl-2-dodecyl-1,
3-propanediol, 2,2-diisopropyl-1,
There is a description of 3-propanediol. However, there is no detailed description of 2-pentyl-2-propyl-1,3-propanediol.

Furthermore, the conventionally known 2,2-dialkyl-substituted 1,
All 3-propanediol is a solid at room temperature, which not only complicates handling of transfer and reaction charge but also solidifies the diol component in the distilling conduit during transesterification in polyester synthesis with polybasic acid, for example. However, problems such as blockage occurred.

Conventionally, as a measure against such a problem, the pipe is forcibly heated from the outside or an anticoagulant such as ethylene glycol is added, but heating the pipe requires facility cost and is also disadvantageous in terms of utility. The addition of the anticoagulant has been a factor causing deterioration of product quality.

In the fields of polyurethane resin, polyester resin, plasticizer, cosmetics and the like, functionalization has recently been required more and more, but no raw material diol capable of coping with such various functionalization has been known to date.

INDUSTRIAL APPLICABILITY The present invention provides a raw material diol capable of coping with high functionalization in the fields of polyurethane resin, polyester resin, plasticizer, cosmetics, etc., a diol which is easy to handle, and a method for producing the same.

(Means for Solving the Problems) As a result of intensive studies made by the present inventors in view of the recent demand for higher functionality, 2-pentyl-2- which is a novel diol.
It was found that propyl-1,3-propanediol has extremely excellent performance when used as a raw material in various applications.

The present invention comprises 2-pentyl-2-propyl-1,3-propanediol and 2-propylheptanal and formaldehyde or paraformaldehyde in the presence of an aqueous solution of an alkali metal hydroxide or an alkaline earth metal hydroxide. 2-pentyl-2-propyl-reacted
This is a method for producing 1,3-propanediol.

That is, the diol of the present invention is 1,3-propanediol having pentyl and propyl groups at the 2-position carbon atom, has no hydrogen atom at the β-position carbon atom like neopentyl glycol, and is , Has an extremely large branched alkyl group.

The diol of the present invention and the compound using this as a raw material have not been known until now, and the 2-pentyl-2 of the present invention has
It is noted that -propyl-1,3-propanediol is a new diol.

The production method of the present invention comprises 2-pentyl-2-propyl-1, by performing a methylolation reaction and a crossed Cannizzaro reaction from 2-propylheptanal and formaldehyde.
3-Propanediol is easily obtained.

The 2-propylheptanal used in the method of the present invention is obtained by subjecting valeraldehyde to a conventional aldol condensation followed by partial hydrogenation.

The reason why the 2-pentyl-2-propyl-1,3-propanediol of the present invention has not been known to date is that the raw material valeraldehyde is not easily available. In other words, the current petrochemistry has been developed on the basis of ethylene and propylene, the aldehydes produced by the oxo method are up to butyraldehyde, and the production of valeraldehyde by the oxo reaction of butene is still produced at the commercial level. Absent. On the other hand, the recent trend toward fine chemicals is seeking new seeds, butene-1
The development of derivatives such as valeraldehyde and further derivatives thereof will be widely demanded from many fields in the future.

As the formaldehyde used in the method of the present invention, an industrially available 5 to 50 wt% formaldehyde aqueous solution can be used as it is, but 70 to 95 w
The use of t% paraformaldehyde is advantageous in terms of dissolution loss of the desired product, 2-pentyl-2-propyl-1,3-propanediol, and reduction of wastewater treatment amount. The formaldehyde used is usually 1
Used in stoichiometric or excess amounts based on moles of 2-propylheptanal. That is, the amount used is preferably 2.0 to 4.0 mol, particularly 2.1 to 3.0 mol.

The alkali metal hydroxide or alkaline earth metal hydroxide used as a catalyst is used as an aqueous solution, and the concentration is 1%.
Any concentration from a saturated solution to a saturated solution may be used, but as with formaldehyde, the desired product, 2-pentyl-
A high concentration is advantageous from the viewpoint of reducing the dissolution loss of 2-propyl-1,3-propanediol and the amount of wastewater treated, and it is also possible to use it at a higher concentration by heating to increase the solubility. The alkali metal hydroxides or alkaline earth metal hydroxides used are generally used in stoichiometric or excess amounts relative to 1 mol of 2-propylheptanal.
That is, the amount used is preferably 1.0 to 1.5 mol, particularly 1.1 to 1.2 mol. Specific examples of alkali metal hydroxides or alkaline earth metal hydroxides include lithium hydroxide,
Although sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide and the like can be mentioned, sodium hydroxide is particularly preferable in view of reaction results and price. The reaction temperature is in the range of about 5 to 100 ° C,
Particularly preferably, the range of 30 to 90 ° C. is selected.

Specific examples of the method for carrying out the methylolation and the cross-Cannizaro reaction from 2-propylheptanal and formaldehyde include a) a method in which 2-propylheptanal, formaldehyde and an alkaline aqueous solution are simultaneously added dropwise, and b) 2- Method of reacting while adding formaldehyde to a mixture of propylheptanal and alkaline aqueous solution, c) While adding aqueous alkali solution to a mixture of 2-propylheptanal and formaldehyde being stirred There are three possible methods of reacting, but according to the study by the present inventors, the method of (c) was found to be the most preferable in terms of yield and economical efficiency or operability of the apparatus.

After the Cannitzaro reaction is completed, the water layer containing a large amount of formate is removed, and the organic layer is washed with water to remove the alkali content. Rinsing with water is preferably performed until the pH of the rinsing water becomes 7 to 7.5. When the pH is 7.5 or more, decomposition occurs during distillation, by-products are remarkably produced, and the yield is reduced.

The reaction solution that has been washed with water may be subjected to simple distillation and, if necessary, rectification using a packed column or a plate column.

(Example) Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1 Into a 2L four-necked flask equipped with a thermometer, a cooling tube, and a dropping funnel, 624.0 g of 2-propylheptanal and 300.0 g of paraformaldehyde (92 ± 1%) were charged, and the dropping funnel was stirred under a nitrogen seal. From 48% -Na
26.6 g of an OH aqueous solution was added dropwise over 5 minutes. The temperature of the reaction solution rose to 55 ° C. Then, the mixture was stirred and aged at 55 ° C. for 2 hours. After that, the temperature was raised, and when the reaction liquid reached 65 ° C., 356.0 g of a 48% -NaOH aqueous solution was added dropwise over 65 minutes. The reaction temperature during dropping was maintained at 75 ° C or lower.
After the reaction was completed, oil-water separation was performed, and the organic layer was washed with 200 cc of water three times. Then the organic layer was distilled under reduced pressure, water,
After removing low boiling components, kettle temperature 175 ° C, 3 mmHg, 135-
A main fraction of 145 ° C. was obtained.

The structure of this product was confirmed by instrumental analysis such as NMR, IR, and GC-MS. In addition, the measurement results are shown in Table 1 together with the characteristic values.

Example 2 146.0 g of adipic acid, 2-pentyl-2-propyl-1,3-propanediol 23 obtained in Example 1
3.0 g, antimony trioxide as an esterification catalyst 0.
15 g was charged into a flask having an internal volume of 1 L equipped with a thermometer, a nitrogen introduction tube, a stirrer, a water separator, and a reflux condenser, and esterification was performed at 195 to 220 ° C. for 6 hours in a nitrogen stream. During the reaction, generated water was distilled off, and 35.7 g of generated water was distilled off by the reaction for 6 hours. Then, at the same temperature, the reaction system was depressurized to 22.9 g of excess diol in the system.
By distillation, 285 g of a polyester polyol having a number average molecular weight of 2000 was obtained. During the reaction, the clogging of the tube due to the precipitation of solid did not occur at all.

Next, after cooling the reaction solution to room temperature, 480 g of cyclohexanone and 35 g of 4,4′-diphenylmethane diisocyanate were added and reacted at 80 ° C. for 2 hours, solid content 40%, viscosity 9400 cps (25 ° C.), number average molecular weight. 25,000 urethane resin compositions were obtained.

Comparative Example 1 Adipic acid 146.0 g, neopentyl glycol 12
9.0 g, antimony trioxide as an esterification catalyst 0.
By the same method as in Example 3 using 15 g, 225 g of a number average molecular weight 2000 polyester polyol was obtained. Since a large amount of neopentyl glycol was deposited in the cooling tube during the reduced pressure reaction, cooling water was stopped and forced heating was performed to dissolve it.

Next, after cooling the reaction solution to room temperature, 400 g of cyclohexanone and 35 g of 4,4′-diphenylmethane diisocyanate were added and reacted at 80 ° C. for 2 hours to give a urethane resin composition having a solid content of 40% and a number average molecular weight of 21,000. Obtained.

Comparative Example 2 146.0 g of adipic acid, 2-butyl-2-ethyl-
By the same method as in Example 3, using 198.0 g of 1,3-propanediol and 0.15 g of antimony trioxide as an esterification catalyst, 285 g of a polyester polyol having a number average molecular weight of 2000 was obtained. During the reaction, the diol was deposited in the cooling pipe and clogged the inside of the pipe, so the cooling water was stopped.
It was dissolved by passing warm water of ℃.

Next, after cooling the reaction solution to room temperature, 400 g of cyclohexanone and 35 g of 4,4′-diphenylmethane diisocyanate were added and reacted at 80 ° C. for 2 hours to give a urethane resin composition having a solid content of 40% and a number average molecular weight of 25,000. Obtained.

Test Example 1 The urethane resin composition shown in Example 2 and Comparative Examples 1 and 2 was applied on a cold-rolled steel sheet having a thickness of 0.8 mm and 300 mm × 50 mm by a spray gun and coated at room temperature for a whole day. After the surface was dried, it was further dried in a heat drier at 100 ° C. for 2 hours. The coating film thickness when completely dried was 0.4 mm.

The obtained test pieces were evaluated by the methods described below.

Loss coefficient (η) The vibration damping performance was evaluated by fixing the two ends of the obtained test piece (rectangular type), applying vibration of 500 Hz to the test piece, and determining the loss coefficient from the resonance performance thereof.

When a water-resistant test piece was immersed in running water (room temperature) for 2 weeks, no change was observed in the state of the coating film compared with before immersion, and a partly changed mark is indicated by a triangle. Those markedly changed are indicated by x marks.

Heat resistance When a test piece was placed in a vertical state at a temperature of 200 ° C. and allowed to stand for 2 hours, no change was observed in the state of the coating film as compared with before heating. △
Marks and marked changes are shown by X marks.

The weather resistance test piece was kept in a sunshine weatherometer for 1200 hours and no change was observed in the state of the coating film as compared with the blank, ◯ mark, partially changed Δ mark, markedly The change is indicated by a cross.

Impact resistance A test piece was placed horizontally, and a height of 500 g was dropped from a predetermined height with a 1/2 inch spherical tip to determine the height when no significant change was observed.

Table 2 shows the above test results.

Example 3 205.5 g of adipic acid, 284.0 g of 2-pentyl-2-propyl-1,3-propanediol, and 83.2 g of 2-ethylhexanol were added to a thermometer, a nitrogen introducing tube, a stirrer, a water diverter, and Charge into a flask with an internal volume of 1 L equipped with a yo-yo reflux condenser, heat in a nitrogen stream while stirring,
When the temperature of the reaction solution reached 140 ° C, as a catalyst,
0.1 g of tetraisopropyl titanate was added, and the temperature of the reaction solution was adjusted to 200 mgKOH / g until the acid value of the reaction solution reached about 20 mgKOH / g while continuously removing the produced water by a water separator.
The reaction was carried out by controlling the temperature to ℃ The reaction time was 2.5 hours. Then, this reaction system was subjected to a transesterification reaction at 220 ° C. for 2.5 hours under a reduced pressure of 2 to 3 mmHg to obtain a predetermined polyester plasticizer. No precipitation of solid was observed during the transesterification reaction.

Comparative Example 3 314.5 g of adipic acid, neopentyl glycol 26
7.4 g and 108.6 g of 2-ethylhexanol were charged into a flask with an internal volume of 1 L equipped with a thermometer, a nitrogen inlet tube, a stirrer, a water separator, and a reflux condenser, and heated in a nitrogen stream while stirring. When the temperature of the reaction solution reached 140 ° C., 0.1 g of tetraisopropyl titanate was added as a catalyst, and the acid value of the reaction solution was increased while continuously removing the generated water by a water separator. About 20mgKOH /
The temperature was controlled to 200 ° C. until the reaction reached g, and the reaction was carried out. The reaction time was 2.5 hours. Then, this reaction system was subjected to a transesterification reaction at 220 ° C. for 2.5 hours under a reduced pressure of 2 to 3 mmHg to obtain a predetermined polyester plasticizer. During the transesterification reaction, the precipitation of neopentyl glycol was remarkable and clogging occurred in the cooling pipe, so cooling water was stopped and the diol was dissolved by forced heating.

Comparative Example 4 205.5 g of adipic acid, 2-butyl-2-ethyl-
241.5 g of 1,3-propanediol and 83.2 g of 2-ethylhexanol were used as a thermometer, a nitrogen introducing tube, a stirrer,
A flask having an internal volume of 1 L equipped with a water separator and a reflux condenser was charged and heated while stirring in a nitrogen stream. When the temperature of the reaction solution reached 140 ° C., tetraisopropyl titanate was used as a catalyst. 0.1 g was added, and while the produced water was continuously removed from the system by a water separator, the temperature was controlled at 200 ° C. to carry out the reaction until the acid value of the reaction solution reached about 20 mgKOH / g. The reaction time was 2.5 hours. Then, this reaction system was subjected to a reduced pressure of 2 to 3 mmHg, and 2
A transesterification reaction was performed at 20 ° C. for 2.5 hours to obtain a predetermined polyester plasticizer. During transesterification reaction 2-
The precipitation of butyl-2-ethyl-1,3-propanediol was remarkable and clogging occurred in the cooling pipe.
The diol was dissolved by passing warm water at 0 ° C.

Test Example 2 A summary of various properties of the polyester plasticizer using the 2-pentyl-2-propyl-1,3-propanediol of the present invention as a raw material and the polyester plasticizers of Comparative Examples 3 and 4 shown in Example 3 is summarized. The results are shown in Table 3. Further, in order to examine water resistance, compatibility (bleeding property) and migration property, 100 parts by weight of a polyvinyl chloride resin (a homopolymer having a Nipolyt SM polymerization degree of 1300) was added to 90 parts by weight of the polyester plasticizer synthesized in Example 3 and a stabilizer. As a mixture, 4 parts by weight of dibasic lead sulfate and 1 part by weight of lead stearate were mixed by a Henschel mixer and kneaded for 7 minutes with an 8-inch roll having a roll temperature of 160 ° C. The obtained sheet is pressed into a press molding machine at 170 ° C. under a pressure of 150 Kg / cm ^{2 for} 3 minutes and cooled for 3 minutes, and a predetermined test piece is prepared from the obtained pressed sheet and subjected to various tests. tried. In addition to the water resistance, bleeding and migration tests, general performances such as tensile test, thermal stability and hardness were also measured. For comparison, in addition to the polyester plasticizers synthesized in Comparative Examples 3 and 4, two kinds of commercially available adipate polyester plasticizers were selected and the same various tests were conducted. Various tests were carried out by the following methods.

Water resistance test A test piece (JIS K7113 No. 2 type test piece) is immersed in a stainless steel container containing hot water which has been preheated to 90 ° C or higher and sealed. This is put in an oven at 100 ° C., left for 48 hours, then taken out, the stickiness on the surface of the test piece is wiped off, and then dried in an oven at 100 ° C. for 2 hours. After drying, the weight of the test piece is measured to determine the rate of change in weight with the weight of the test piece before the test.

Bleedability test A test piece having a length of 60 mm, a width of 30 mm, and a thickness of 1 mm was placed in a constant temperature and constant humidity state of a temperature of 70 ° C. and a relative humidity of 80%, and the surface state of the test piece was observed over time to determine whether there was bleeding. Determine the degree.

Migration test AB 50 mm long, 50 mm wide, 1 mm thick test piece
After sandwiching the S resin plate or the AS resin plate with a load of 1 Kg and leaving it at a temperature of 70 ° C. for 168 hours, the migration property is calculated from the weight change of the test piece before and after the test.

Regarding the transfer to an acrylic coated plate, the transfer property is calculated from the weight change of the test piece before and after the test by sandwiching the test piece between the acrylic coated plates and leaving it for 240 hours at a weight of 1 kg and a temperature of 70 ° C. and a relative humidity of 80%.

Thermal stability test 1 test piece with a length of 30 mm, width of 25 mm and thickness of 1 mm
Put in a gear oven at 80 ° C. and observe the colored state of the test piece every 10 minutes for comparison.

Tensile test Based on JIS K6723.

Hardness JISK6301 (spring type hardness test according to A type)
Compliant with.

The results are summarized in Table 4.

From the above results, 2-pentyl-2-propyl-of the present invention
When 1,3-propanediol is used as a raw material for urethane paints, for example, it is compared with those made from neopentyl glycol as a raw material, and has extremely excellent water resistance, heat resistance, weather resistance, impact resistance, vibration damping property, etc. It was confirmed that it had the performance of. Similarly, when used as a raw material of a polyester plasticizer, excellent water resistance, compatibility, and non-migratory property were recognized as compared with a commercially available polyester plasticizer or neopentyl glycol as a raw material. Further, a significant improvement in performance was recognized as compared with 2-butyl-2-ethyl-1,3-propanediol shown in the comparative example.

(Effect of the Invention) The 2-pentyl-2-propyl-1,3-propanediol of the present invention was liquid at room temperature. Currently known various 2,2-dialkyl-substituted 1,3-propanediols include neopentyl glycol,
This is a remarkable property given that it is all solid at room temperature. It is obvious that the difference in whether the raw material used for the reaction is a solid or a liquid at room temperature makes a great difference in operation not only in the case of transferring the raw material but also in the ease of charging into the reactor. Is.

Since 2-pentyl-2-propyl 1,3-propanediol of the present invention is a liquid at room temperature, when producing a polyester polyol, a polyester plasticizer, or the like,
When extracting excess glycol under reduced pressure, there is no need to provide special expensive heating and heat retention equipment because it does not cause blockage in the pipe.

Further, 2-pentyl-2-propyl-1,3-of the present invention
Since propanediol is liquid at room temperature,
It can be used for various purposes such as heat medium, reaction solvent, vehicle for conductor film formation.

As a matter of course, the 2-pentyl-2-propyl-1,3-propanediol of the present invention has an alcoholic primary hydroxyl group with extremely high reactivity at the terminal like neopentyl glycol, and therefore various synthetic methods are available. It can be used for the purpose of reaction, for example, after dibasic acid such as adipic acid and a polyester polyol, when the coating film physical properties were evaluated by urethane formation with diisocyanate such as phenylmethane diisocyanate, compared to neopentyl glycol, It was found to have excellent water resistance, heat resistance, weather resistance, impact resistance, and vibration damping properties.

Further, for example, 2-pentyl-2-propyl-1, of the present invention,
When 3-propanediol was used as the polyester plasticizer, particularly excellent performance was found in water resistance, compatibility, and non-migration property. 2-butyl-2-ethyl-1,3
-Significant improvement in performance was observed compared to propanediol.

Thus, 2-pentyl-2-propyl-1, of the present invention,
3-Propanediol is easy to handle by taking advantage of its liquid state at room temperature, and is used as a heat medium, reaction solvent, vehicle for conductor film formation, and polyurethane resin that has recently been required to have higher functionality. It is useful as a raw material diol for polyester resins, plasticizers and cosmetics.

 ─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-53-65808 (JP, A) JP-A-57-53421 (JP, A) JP-A-56-30932 (JP, A) JP-A-48- 64008 (JP, A) JP 41-8769 (JP, B1) JP 48-43085 (JP, B1)

Claims (2)

[Claims] 1. 2-Pentyl-2-propyl-1,3-propanediol 2. 2-Pentyl-2-propyl-1,3-propane obtained by reacting 2-propylheptanal with formaldehyde or paraformaldehyde in the presence of an aqueous solution of an alkali metal hydroxide or an alkaline earth metal hydroxide. Manufacturing method of diol.