JPH1150086A - Castor oil-modified polyol and curable composition mixed with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new castor oil-modified polyol obtained by bonding castor oil or hydrogenated castor oil with castor oil fatty acid or 12- hydroxystearic acid, or a condensed fatty acid of these fatty acids, and to provide a curable composition having properties such as a low softening point or a small hardness, especially excellent properties at a low temperature by mixing with the castor oil-modified polyol. SOLUTION: This castor oil-modified polyol is produced by heating castor oil or hydrogenated castor oil together with castor oil fatty acid or 12- hydroxystearic acid, or a condensed fatty acid of these fatty acid, or further these methyl ester in the presence of a catalyst such as an acid or an alkali, and the objective urethane-based curable composition is obtained by mixing the sole castor oil-modified polyol or a mixture with another polyol to a polyisocyanate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a special castor oil-modified polyol derived from castor oil or hydrogenated castor oil, and a curable composition comprising a polyisocyanate alone or a polyol mixture containing only one or other polyols, The present invention relates to a urethane-based curable composition that provides a cured product having excellent low-temperature water resistance, mechanical properties, and electrical properties.

[0002]

2. Description of the Related Art Castor oil is the only compound having a hydroxyl group among natural fats and oils used industrially, and is therefore used as a polyol in a wide range of fields as a raw material for polyurethane and for various uses. Castor oil, as it is, has a relatively low viscosity, has many hydrocarbon chains, and the hydroxyl groups are far apart, which makes it more water-resistant and electric than polyether polyols and polyester polyols commonly used as polyurethane polyols. A polyurethane material with excellent properties and imparting flexibility. Castor oil has the above-mentioned properties, and is therefore used in a wide range of fields such as polyurethane for electric insulation, paint, and adhesives.

[0003] However, as the uses of polyurethanes become widespread and as technology advances, it is necessary to respond to diversification and higher functionality, and castor oil alone cannot satisfy these required performances in many sectors. It came out. Therefore, many improvements of castor oil itself have been proposed.

As a method for improving castor oil, a method of transesterifying castor oil with a fat or oil having no hydroxyl group (JP-A-59-226016) and a method of partially acetylating or partially dehydrating castor oil (JP-A-60-53522) Method for acylating most of the hydroxyl groups of castor oil
100513), a method of reacting a partially acylated castor oil with an epoxy resin (Japanese Patent Application Laid-Open No. 62-74925) and the like have been proposed, and their respective purposes have been achieved. However, especially at low temperatures water resistance, mechanical properties, electrical properties,
And other excellent polyurethane cured products were requested, and there were no satisfactory products.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on the above-mentioned cured polyurethane having excellent water resistance at low temperatures, mechanical properties, electrical properties, and the like. As a result, castor oil or hydrogenated castor oil was obtained. Furthermore, the inventors have found that castor oil-modified polyols obtained by combining castor oil fatty acids or 12-hydroxystearic acid, or condensed fatty acids of these fatty acids have excellent properties, and have reached the present invention.

That is, the present invention relates to castor oil or hydrogenated castor oil, castor oil fatty acid or 12-hydroxystearic acid, or a condensed fatty acid of these fatty acids.
By heating these methyl esters in the presence of a catalyst such as an acid or an alkali, the castor oil-modified polyol of the present invention can be easily produced.

The castor oil-modified polyol of the present invention can adjust the molecular weight to various sizes. Thereby,
The properties of the polyurethane cured product obtained by blending them will also change in various ways, and it becomes possible to design a cured product having properties suitable for the purpose.

When the castor oil-modified polyol of the present invention is used as a polyol component of a urethane curable composition, it can be used alone or in combination with another polyol.

Here, when blended with another polyol,
Compared to the original castor oil or hydrogenated castor oil, the castor oil-modified polyol of the present invention has a large number of ester bonds and a relatively small content of hydroxyl groups, and therefore has a poor compatibility with hydrocarbon-based polyols and the like. The solubility is improved.

The castor oil-modified polyol of the present invention thus obtained is blended with the polyol alone or with another polyol, and the polyurethane cured product obtained by blending the polyisocyanate with the polyol is particularly water-resistant at low temperatures, and has excellent mechanical properties. The inventors have found that the electrical characteristics and electrical characteristics are excellent, and have reached the present invention.

As described above, the present invention relates to a castor oil-modified polyol obtained by combining castor oil or hydrogenated castor oil with castor oil fatty acid or 12-hydroxystearic acid, or a condensed fatty acid of these fatty acids. It is a urethane curable composition comprising a polyisocyanate.

The process for producing the castor oil-modified polyol of the present invention comprises the steps of adding castor oil fatty acid, 12-hydroxystearic acid, a condensed fatty acid of these fatty acids, and a methyl ester of these fatty acids to castor oil or hydrogenated castor oil. Heating in the presence of a catalyst such as
It can be easily obtained by removing by-product water or methanol out of the system.

The hydrogenated castor oil in the present invention is obtained by hydrogenating castor oil with high-pressure hydrogen gas in the presence of a catalyst such as nickel. The degree of unsaturation can be controlled by the degree of hydrogenation, but this product is completely hydrogenated.

The castor oil fatty acid in the present invention can be obtained by subjecting castor oil to alkaline hydrolysis according to a conventional method. This castor oil fatty acid contains a partially condensed fatty acid because it condenses itself to form estolide.

The castor oil fatty acid methyl ester of the present invention is usually synthesized by reacting castor oil with an excess of methanol in the presence of a catalyst (such as an alcoholate).

The 12-hydroxystearic acid in the present invention is obtained by hydrolyzing hydrogenated castor oil by a conventional method. The methyl ester is obtained from hydrogenated castor oil by reacting excess methanol in the presence of a catalyst.

The condensation of these fatty acids in the present invention is facilitated by heating castor oil fatty acid or 12-hydroxystearic acid to about 200 ° C. The degree of condensation can be freely controlled by regulating the neutralization value. This product is a condensed fatty acid having a degree of condensation of 2 to 5.

In the present invention, the methyl ester of a condensate of those fatty acids is

The condensed fatty acid is converted to a methyl ester with an excess of methanol in the presence of a catalyst, or the methyl ester of a castor oil fatty acid or the methyl ester of 12-hydroxystearic acid is heated in the presence of a catalyst to convert methanol. It is obtained by condensation while removing it out of the system.

The castor oil-modified polyol of the present invention preferably has a hydroxyl value of 20 to 130. In particular, the hydroxyl value is 40-
When 85 is a cured polyurethane product, it has excellent low-temperature properties.

Other polyols of the present invention include polyether polyols, polyester polyols, acrylic polyols generally used for polyurethanes,
Large molecular weights such as hydrocarbon polyols,
Medium to low molecular weight polyols such as propylene oxide adducts of glycerin, propylene oxide adducts of trimethylolpropane, propylene oxide adducts of bisphenol A, polypropylene glycol, tripropylene glycol, dipropylene glycol, propylene glycol, tetramethylene glycol, etc. included.

Although the above-mentioned hydrocarbon polyol has a high viscosity, it is widely used in the field of electric insulation because of its excellent electric properties. Examples of this product include “P butadiene polyol” manufactured by Idemitsu Petrochemical Co., Ltd.
BR-45HT "," G-1000 "manufactured by Mitsui Nisso Urethane Co., Ltd., and" Polytail HA "manufactured by Mitsubishi Chemical Corporation which is a polyolefin polyol.

The compounds contained in the polyisocyanate of the present invention include tolylene diisocyanate, diphenylmethane diisocyanate, diphenylpropane diisocyanate, xylylene diisocyanate, diphenyl sulfone diisocyanate, hexamethylene diisocyanate, 3-isocyanatomethyl-3,5,5-trimethyl Cyclohexyl isocyanate, 3,3′-diisocyanate dipropyl ether, diphenyl ether—
4,4'-diisocyanate, isophorone diisocyanate and the like. Prepolymers having terminal isocyanate groups derived from these polyisocyanates are likewise used.

The mixing ratio of the castor oil-modified polyol of the present invention, other polyols and polyisocyanate is such that the isocyanate group in the polyisocyanate is 0.8 to 1.4 equivalents to the total amount of hydroxyl groups. , Since a sufficiently cured product can be obtained. At this time, a curing accelerator (organometallic compound, hindered tertiary amine, etc.)
May be added as necessary. Curing may be performed slowly at a low temperature or may be accelerated by heating.

The composition of the present invention includes a filler or pigment such as talc, clay, calcium carbonate, baryta powder, silica powder, alumina, carbon black, titanium oxide, iron oxide, etc., a phosphorus compound, a halogen compound, an oxide, If necessary, additives such as a flame retardant such as antimony, an antioxidant, an antioxidant, and an ultraviolet absorber may be added.

The composition of the present invention comprises a casting composition, an impregnating composition, a coating agent, an adhesive, a paint, a caulking agent,
It is useful for applications such as potting agents, sealants, foams, encapsulating materials, lining materials, packing materials, industrial rubber materials, and the like. The composition of the present invention is particularly excellent in water resistance at low temperatures, mechanical properties, and electrical properties, and is useful for applications requiring these properties.

[0026]

EXAMPLES The present invention will be further described with reference to examples below, but the present invention is not limited to these examples. Parts in the examples are parts by weight.

[Synthesis of Castor Oil-Modified Polyol] Example 1 Purified castor oil (having a hydroxyl value of 160 and a viscosity of 700 cps / 25) was placed in a reaction flask equipped with a stirrer, a thermometer, a distilling tube connected to a cooler, and a nitrogen gas introducing tube. ℃) 930 parts, castor oil fatty acid methyl ester 310 parts, sodium methylate 28%
5.0 parts of a methanol solution (catalyst) are charged, and the reaction temperature is gradually raised from 40 ° C. to 120 ° C. under nitrogen gas introduction. It took about 6 hours. During that time, the by-product methanol is distilled out of the system through the distillation pipe. Further, the reaction is performed for one hour under reduced pressure. The reaction mixture was cooled, washed with water and dehydrated to obtain Example 1. The analysis values of Example 1 were a hydroxyl value of 125 and a viscosity of 640.
cst / 25 ° C.

Example 2 In the same apparatus as in Example 1, 930 parts of purified castor oil, 300 parts of castor oil fatty acid, and 3.0 parts of p-toluenesulfonic acid were charged into a reaction flask, and the reaction temperature was raised to 160 to 150 ° C under nitrogen gas introduction. The reaction was carried out at 200 ° C. for 7 hours, and the by-product water was distilled out of the system from the distillation pipe. The reaction mixture was treated as in Example 1 to give Example 2. The analysis values of Example 2 were a hydroxyl value of 103 and a viscosity of 1110 cst / 25 ° C.

Example 3 Example 3 was obtained in the same manner as in Example 2 except that 930 parts of refined castor oil and 600 parts of castor oil fatty acid were used. Example 3
Is a hydroxyl value of 80.3 and a viscosity of 1200 cst / 2.
5 ° C.

Example 4 Example 4 was obtained in the same manner as in Example 2 except that 930 parts of refined castor oil and 600 parts of condensed castor oil fatty acid (average dimer) were used. The analysis values of Example 4 were a hydroxyl value of 85.5 and a viscosity of 1150 cst / 25 ° C.

Example 5 Example 5 was obtained in the same manner as in Example 2 except that 930 parts of purified castor oil and 750 parts of castor oil fatty acid were used. Example 5
Is a hydroxyl value of 73.0 and a viscosity of 1250 cst / 2.
5 ° C.

Example 6 Example 6 was obtained in the same manner as in Example 2 using 930 parts of purified castor oil and 1500 parts of castor oil fatty acid. The analysis value of Example 6 was a hydroxyl value of 45.0 and a viscosity of 1630 cst /
25 ° C.

Example 7 Example 7 was repeated in the same manner as in Example 2 using 930 parts of refined castor oil and 1500 parts of 12-hydroxystearic acid.
I got The analysis value of Example 7 was a hydroxyl value of 51.0 and a viscosity of 2
180 cst / 25 ° C.

Example 8 Example 8 was repeated in the same manner as in Example 2 except that 930 parts of hydrogenated castor oil and 1500 parts of 12-hydroxystearic acid were used.
I got The analysis values of Example 8 were a hydroxyl value of 52.0 and a viscosity of 5
It was 865 cst / 25 ° C.

Comparative Example 1 (Partially Dehydrated Castor Oil) In the same apparatus as in Example 1, 930 parts of purified castor oil and 0.9 part of sodium sulfate were charged into a reaction flask, and the mixture was introduced under nitrogen gas and reduced under reduced pressure (degree of vacuum: approx. The reaction was carried out at a reaction temperature of 190 to 220 ° C. for about 3 hours at 30 mmHg, and the by-product water was distilled out of the system from the distillation pipe to obtain Comparative Example 1 (partially dehydrated castor oil). The analysis value of Comparative Example 1 was a hydroxyl value of 120 and a viscosity of 400 cps / 25 ° C.

Comparative Example 2 (Transesterified product) In the same apparatus as in Example 1, 930 parts of purified castor oil, 900 parts of purified rapeseed oil, 134 parts of trimethylolpropane, and 16 parts of a methanol solution of 28% sodium methylate were charged into a reaction flask. The reaction temperature was set to 4 under nitrogen gas introduction.
The temperature was gradually raised from 0 ° C. to 160 ° C. (about 5 hours) to obtain Comparative Example 2 (transesterified product). The analysis values of Comparative Example 2 were a hydroxyl value of 160 and a viscosity of 250 cps / 25 ° C.

[Method of preparing cured product] Examples 1 to 8 and Comparative Example 1
To 2 alone as a polyol component, which is added to carbodiimide-modified 4,4′-diphenylmethane diisocyanate (“Millionate MT” manufactured by Nippon Polyurethane Industry Co., Ltd.)
L ") was mixed so that the NCO / OH equivalent ratio became 1.05, and the mixture was stirred at 60 ° C for 2 minutes, and then transferred to a container.
Cured at 10 ° C. for 10 hours. Thereby, thickness 3mm and 1
A cured product of 0 mm was obtained.

[Cured product property test method] Hardness: JIS K 7215 Tensile strength; JIS K 6301 Tear strength; JIS K 6301 Elongation; JIS K 6301 Glass transition temperature; Apparatus: Seiko Denshi Kogyo Co., Ltd., differential scanning calorimetry Total Measurement conditions: Heating rate 10 ° C / min

[Characteristics of Examples and Comparative Examples] Table 1 shows the characteristics of cured products of Examples and Comparative Examples.

[Table 1] As shown in Table 1, the products of the present invention have excellent low-temperature properties such as a low glass transition point and low hardness at low temperatures.

[Volume resistivity and solid dynamic viscoelasticity] Cured product preparation method: using castor oil in Examples 6, 7 and 8 and Comparative Example

It was prepared by the method described above. Measurement method; Volume resistivity: JIS K 6911 Solid dynamic viscoelasticity: Apparatus: DMS110 manufactured by Seiko Instruments Inc. Measurement method: Frequency 1 Hz, heating rate 2.5 ° C./min, tensile mode Measurement result; Measurement result Is shown in Table 2.

[0041]

[Table 2] Table 2 shows that the product of the present invention has slightly lower volume resistivity than castor oil, but has excellent low-temperature properties because its solid dynamic viscoelasticity shows a low temperature.

[Heat Resistance Test] Sample preparation: Using Examples 6 to 8 and Comparative Example 1,

It was prepared by the method described above. Measurement conditions: A cured product having a thickness of 10 mm is used and heated in a hot air dryer at 120 ° C. for a predetermined time. After allowing the test sample to cool to room temperature, the hardness (JIS K7215) was measured. Measurement results: The measurement results are shown in Table 3.

[0043]

[Table 3] According to Table 3, the thermal stability at 120 ° C. is very excellent.
The change is small even at 000 hours.

[Compatibility with Hydrogenated Polybutadiene Polyol] Test Method: Hydrogenated polybutadiene polyol was prepared using a sample (PBR-45HT) manufactured by Idemitsu Petrochemical Co., Ltd.
And 8) were mixed at a prescribed ratio in a mixture, stirred thoroughly at room temperature, left standing for 24 hours, and visually observed to determine. Here, “PBR-45HT” means a number average molecular weight of 2800,
2.2 to 2.4 functional groups, hydroxyl value 46, iodine value 39
A hydrogenated polybutadiene polyol having a characteristic value of 8. Measurement results: The measurement results are shown in Table 4.

[0045]

[Table 4] As shown in Table 4, the product of the present invention is superior to castor oil in compatibility with hydrogenated polybutadiene polyol.

[Test of cured product of blend with PBR-45HT] Method for preparing cured product; PBR was prepared using Examples 6, 7 and 8.
-45HT and 1/1 in a ratio, using this polyol,

A cured product was prepared by the method described above. Method for measuring properties of cured product;

The cured product was measured according to the property test method. Test results: Test results are shown in Table 5.

[0047]

[Table 5] From Table 5, the cured product of the compound with PBR-45HT is P
This shows that a cured product having a low hardness and a high elongation is provided as compared with BR-45HT alone.

[0048]

The castor oil-modified polyol of the present invention has characteristics of low softening point and low hardness when cured into a polyurethane containing the same. They exhibit outstanding properties, especially at low temperatures.

Claims (2)

[Claims] 1. A castor oil-modified polyol obtained by combining a castor oil or a hydrogenated castor oil with a castor oil fatty acid or 12-hydroxystearic acid, or a condensed fatty acid of these fatty acids. 2. A curable composition comprising the castor oil-modified polyol according to claim 1, another polyol and polyisocyanate.