JP2001261798A - Method for producing lactone-based polyol and polyurethane resin using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lactone-based polyol for polyurethane resin raw materials capable of producing a polyurethane resin not causing problems such as blooming phenomenon to the surface of molded product and lowering of physical properties of molded product and a polyurethane resin using the above polyol. SOLUTION: This method for producing a lactone-based polyol is characterized in that the lactone-based polyol is obtained by carrying out ring-opening polymerization reaction of lactone monomer at 165-175 deg.C in the presence of an organotin-based catalyst in an amount of 0.0001-0.001 wt.% based on an initiator having an active hydrogen and composed of a polyhydric alcohol or polyvalent amine and finishing the reaction at the point when an amount of the lactone monomer became <=0.5 wt.% and total amount of cyclic ester which is a reaction subsidiary product in the polyol is <=0.5 wt.%. This urethane resin is obtained by the above lactone-based polyol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a lactone-based polyol for use as a polyurethane resin raw material, wherein the total amount of cyclic ester compounds as reaction by-products is 0.5% by weight or less. It is an object of the present invention to provide a urethane resin which solves problems such as prevention of physical property deterioration, suppression of blooming phenomenon on a molded product surface, and breakage of yarn.

[0002]

2. Description of the Related Art Lactone-based polyols are used in many fields because of their differences in average molecular weight and number of functional groups and excellent hydrolysis resistance. For example, a lactone-based polyol obtained by ring-opening polymerization of ε-caprolactone using a polyhydric alcohol as an initiator is very useful as a raw material of a polyurethane resin, and takes advantage of its excellent physical properties, characteristics such as elasticity,
Elastomers such as conveyor belts, copier blades,
It is used for urethane fibers and various industrial chips.

[0003] Such lactone-based polyols are usually produced by ring-opening polymerization of a lactone monomer in the presence of a catalyst using a compound having active hydrogen such as glycol as an initiator.

[0004] Many compounds are known as catalysts used in the reaction. For example, acids such as inorganic acids and organic acids, Li, Na, K, Mg, Al, Ca, Ti, V, C
r, Mn, Fe, Co, Ni, Cu, Zn, Pb, P
b, chlorides, oxides, and hydroxides of metals such as Sr, Zr, Pd, and Sn, metal salts of fatty acids such as acetic acid, oxalic acid, octylic acid, lauric acid, and naphthenic acid of the above metals, sodium methylate, and sodium Ethylate, aluminum tetraisopropoxide, isopropyl titanate,
alcoholates such as n-butyl titanate, phenenolates such as sodium phenolate, Al, Ti, Z
It is known to use all commonly used catalysts such as organometallic compounds of metals such as n, Zr, Sn, Pb and the like.

However, when these lactone-based polyols are synthesized, the generation of reaction by-products cannot be avoided, and cyclic ester such as dimer, trimer, tetramer, and pentamer of the lactone monomer must be produced. Compounds form in small quantities. These have a cyclic structure and do not have active hydrogen such as a hydroxyl group capable of reacting with isocyanate.

The lactone polyol is usually a solid at room temperature, and when it is formed into a molded article of a urethane resin such as a roller or a blade, the lactone polyol causes blooming on the surface of the molded article with time and is used for molding the urethane resin. In some cases, the mold may become soiled, and the workability during manufacturing may be significantly deteriorated. This is considered to be because by-products remain in the resin when the lactone polyol and the isocyanate are reacted to obtain the urethane resin. For example, Japanese Patent Application Laid-Open No. H10-310636 discloses that the lactone dimer content is reduced. A method for producing a lactone-based polyol that can be produced has been proposed.

However, according to the findings obtained by the present inventors, the problem of the decrease in the strength of the urethane resin could not be solved only by reducing the content of the lactone dimer. It is rather 3
It was found that they were a dimer, tetramer, or pentamer, and were not caused only by the lactone dimer. It has been found that the cause of the above problems including the decrease in strength should be considered to be the total content of the cyclic ester compound present in the lactone polyol. Therefore, the present inventors have studied on a method for producing a lactone-based polyol that can reduce the total content of the cyclic ester compound.

[0008]

That is, an object of the present invention is to produce a lactone-based polyol for use as a raw material for a polyurethane resin which can produce a polyurethane resin which does not cause deterioration of the physical properties of the molded product and does not cause blooming on the surface of the molded product. A method and a polyurethane resin using the same.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve these objects, and as a result, they have been able to polymerize lactone by polymerizing lactone at a specific catalyst, a specific reaction temperature and a specific reaction condition. The inventors have found that a lactone-based polyol having a total content of ester compounds of 0.5% by weight or less was obtained, and completed the present invention.

That is, the present invention relates to a method for producing an active tin catalyst comprising a polyhydric alcohol or a polyhydric amine in the presence of an organotin-based catalyst in an amount of 0.0001 to 0.001% by weight.
A lactone-based polyol obtained by subjecting a lactone monomer to a ring-opening polymerization reaction at a reaction temperature of 165 ° C. to 175 ° C. and terminating the reaction when the lactone monomer becomes 0.5% by weight or less. It is intended to provide a method for producing a lactone-based polyol, wherein the total amount of the cyclic ester compound is 0.5% by weight or less. It is another object of the present invention to provide an excellent urethane resin capable of reducing strength properties, suppressing blades and preventing yarn breakage by using the lactone polyol for a polyurethane resin.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the lactone monomer used in the present invention include, for example, δ-valerolactone, β
-Methyl-δ-valerolactone, ε-caprolactone,
α-methyl-ε-caprolactone, β-methyl-ε-caprolactone, γ-methyl-ε-caprolactone, β,
δ-dimethyl-ε-caprolactone, 3,3,5-trimethyl-ε-caprolactone, enantholactone, dodecanolactone and the like. One or more of these monomers can be used as a mixture.

The initiator of the present invention is a polyhydric alcohol or amine, and any other compound may be used as long as it has two or more active hydrogens capable of reacting with an isocyanate group. Examples of the polyhydric alcohol include ethylene glycol, 1,2-propylene glycol, 1,
3-propylene glycol, 1,2-butanediol,
1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl1,5
-Pentanediol, 1,6-hexanediol, 2,
2,4-trimethyl-1,3-pentanediol, 2-
Ethyl 1,3-hexanediol, 2-methyl 1,8-
Octanediol, 1,9-nonanediol, 1,10
-Decanediol, 1,12-octadecanediol,
Examples include polyols such as glycerin, trimethylolpropane, trimethyloloctane, and pentaerythritol.

Examples of polyamines include low molecular weight polyamines such as ethylenediamine and hexaethylenediamine;
Further, low molecular weight alkanolamines such as ethanolamine and the like can be mentioned. In addition, polyoxypropylene glycol, polyoxybutylene glycol, polytetramethylene glycol, acrylic polyl, styrene allyl alcohol copolymer, polyester polyol, or the like having a hydroxyl group at a terminal can also be used as the initiator.
These can be used alone or in combination of two or more.

As the catalyst of the present invention, any organotin-based catalyst which is usually used for ring-opening polymerization of a lactone monomer can be used. For example, tin octylate,
Dibutyltin oxide, dibutyltin dilaurate,
n-butyltin hydroxy oxide and the like.
Inorganic tin catalysts have higher activity than organic tin catalysts, and it is difficult to control ring-opening polymerization. In addition, when the lactone-based polyol is stored in a molten state, the activity of the lactone-based polyol causes the polymerization reaction and the formation of a cyclic ester compound to be caused to increase, so that an organotin-based catalyst is more preferable.

The amount of the catalyst used is 1 p
pm to 10 ppm (0.001 to 0.001% by weight)
It is. When the amount of the catalyst is less than 1 ppm, the reaction rate is slow. On the contrary, when the amount of the catalyst exceeds 10 ppm, not only does the hydrolysis resistance of the lactone-based polyol and the urethane resin using the same deteriorate, but also the hue and thermal stability deteriorate. Not preferred.

The reaction method may be any method as long as it is a commonly used ring-opening polymerization method of lactone, and may be any of bulk polymerization, solution polymerization, suspension polymerization and the like. Preferably, it is a bulk polymerization method.

The reaction temperature of the present invention is from 165 ° C to 175 ° C.
It is. When the reaction temperature is lower than 165 ° C., the reaction rate is remarkably slow, and a long time is required for the synthesis, which is not practical in industry. Conversely, when the reaction temperature is higher than 175 ° C., it causes coloring due to the oxidation reaction, or the reaction is too fast, and the generation rate of the cyclic ester compound is also increased, and the content of the cyclic ester compound reaches 0.5% by weight or less. This makes it difficult to control the reaction at the time of termination.

The reason for terminating the reaction when the lactone monomer becomes 0.5% by weight or less is that as the ring-opening addition polymerization reaction proceeds, the residual amount of the lactone monomer in the system gradually decreases and remains almost unchanged. This is because when the state is reached and the reaction is continued, the cyclic ester compound increases. The reaction time is preferably 8 to 12 hours, and the time when the amount of the residual monomer becomes 0.5% by weight or less is defined as the reaction end point, and the temperature is immediately cooled to 100 ° C. or less to terminate the polymerization reaction. Unnecessary heat history after the reaction end point is not preferable because the amount of the cyclic ester compound gradually increases due to the transesterification reaction regardless of the catalyst and reaction conditions used.

In the lactone polyol obtained by the present invention, the total amount of the cyclic ester compound is 0.5% by weight or less, and the content of the
0.08% by weight, trimer: 0.05 to 0.12% by weight,
Tetramer: 0.02 to 0.08% by weight, pentamer: 0.02
~ 0.05% by weight. The total amount of the cyclic ester compound in the lactone-based polyol obtained by the operation of the present invention does not exceed 0.5% by weight, but if it exceeds 0.5% by weight, these problems will occur. In order to overcome the above, a post-treatment for reducing the amount of the cyclic ester compound is required, and the operation becomes very inefficient.

The content of the cyclic ester compound is measured by a gas chromatograph according to the gas chromatography conditions and analytical methods described in Examples. In particular, when the molecular weight is relatively large such that the molecular weight exceeds 1,000, it is desirable to perform the following pretreatment. Dissolve the lactone-based polyol in a solvent containing the internal standard, extract it with hexane, precipitate the lactone-based polyol,
The cyclic ester compound is extracted into the hexane layer. This is measured by gas chromatography, and the amount of the cyclic ester compound contained in the lactone-based polyol can be calculated from the internal standard. The cyclic ester compound of the present invention refers to a dimer, trimer, tetramer, pentamer or the like of a lactone monomer.

The lactone-based polyol and organic polyisocyanate obtained by the above-mentioned method and, if necessary, a chain extender are used, and conventionally known methods such as a one-shot method,
The polyurethane resin of the present invention can be obtained by a prepolymer method or the like.

The organic polyisocyanate used in the present invention is 4,4'-diphenylmethane diisocyanate,
Carbodiimide-modified diphenylmethane diisocyanate (liquefied MDI), 2,4-tolylene diisocyanate or 2,6-tolylene diisocyanate, m- or p-phenylene diisocyanate, p-xylene diisocyanate, ethylene diisocyanate, tetramethylene-1,4-diisocyanate Hexamethylene diisocyanate, 3,3'-dichloro-4,4'-biphenylene diisocyanate, 4,4'-biphenylene diisocyanate or isophorone diisocyanate, cyclohexane diisocyanate, xylylene diisocyanate, dicyclohexyl methane diisocyanate, triden diisocyanate, 1,5- Naphthalene diisocyanate and crude diphenylmethane diisocyanate. The polyisocyanates may be used alone or as a mixture.

In the synthesis of the polyurethane resin,
In some cases, low molecular weight compounds having two or more active hydrogens are usually used as chain extenders, but these active hydrogen compounds can also be used in the present invention.

Representative examples of active hydrogen-containing low molecular weight compounds include, for example, ethylene glycol, butanediol, propylene glycol, 1,6-hexanediol, 1,4-bis (β-hydroxyethoxy) benzene, 1,4-cyclohexane Diols such as diols, bis (β-hydroxyethyl) terephthalate, xylene glycol and the like, water, hydrazine, ethylenediamine, isophoronediamine, piperazine, phenylenediamine, tolylenediamine, adipic dihydrazide, isophthalic dihydrazide and the like. May be used alone or as a mixture. If necessary, a monohydric low molecular alcohol, low molecular diamine, or the like can be used as a modifier.

The catalyst used in the present invention may be a catalyst commonly used in producing polyurethane, and may be, for example, an amine compound, an organometallic compound or an imidazole compound.

In addition to lactone-based polyols, polyols that are commonly used for urethane resins such as polyoxyalkylene polyols, acrylic polyols, polybutadiene polyols, and polyester polyols such as adipate can be used without departing from the scope of the present invention. They may be used as a mixture.

In addition to the above-mentioned components, a flame retardant, a filler, an antistatic agent, a colorant and the like can be added according to the required performance as long as the object of the present invention is not deviated.

With respect to a production method for obtaining a polyurethane resin using the above-mentioned raw materials, a known technique of a urethane reaction is used. For example, after mixing a polyol and a low molecular weight compound having active hydrogen and preheating it to about 40 to 100 ° C., the polyisocyanate is used in such an amount that the ratio of the number of active hydrogens to the NCO group of these compounds becomes 1: 1. A solid-state polymerization method in which a compound is added, and the mixture is stirred vigorously for a short time and then left at about 50 to 150 ° C. Further, the reaction can be carried out by reacting a polyol and a polyisocyanate in advance to obtain a polyurethane prepolymer, and then reacting the polyurethane prepolymer with a chain extender. The polyisocyanate compound is used in a very slight excess because it is usually affected by moisture and the like. These reactions are carried out using dimethylformamide, diethylformamide, dimethylsulfoxide, dimethylacetamide, tetrahydrofuran,
A solution reaction method performed in a solvent composed of one or more of methyl ethyl ketone, benzene, toluene, tricrene and the like can also be used. In this case, when the concentration is in the range of 10 to 40% by weight, it is preferable to obtain a high molecular weight polyurethane resin.

[0029]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but it should not be construed that the invention is limited thereto. In the following description, “parts” and “%” are based on weight unless otherwise specified.

Example 1 A 1-liter four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a condenser was charged with diethylene glycol 31.
g, 947 g of ε-caprolactone and 0.005 g of stannous octoate as a catalyst were reacted at 170 ° C. while stirring under nitrogen, and sampling was performed every two hours.

<Analytical Method> 1 g of a lactone-based polyol is placed in a test tube with a lid, and an internal standard solution (diisobutyl phthalate / tetrahydrofuran: 20 g / l) is accurately added with a 0.5-ml pipette and dissolved while warming in a warm bath. Subsequently, 2.5 ml of n-hexane was added and mixed vigorously with a microspatula to precipitate a lactone-based polyol. At this time, the internal standard diisobutyl phthalate and the low molecular weight lactone are extracted into the n-hexane layer.

The n-hexane layer was measured with a gas chromatograph manufactured by Shimadzu Corporation under the following gas chromatography conditions, and the amount of the lactone monomer and the amount of the cyclic ester compound in the lactone-based polyol were quantified from a previously measured calibration curve. After 10 hours, the residual amount of the lactone monomer is 0.1%.
It became 2% by weight, and the reaction was completed. The gas chromatographic chart at this time is shown in FIG. 1, and the amount of the cyclic ester compound is shown in Table 1.

<Gas chromatography conditions> Model Shimadzu GC-7A Conditions Column glass: 5% SE-30 1.1 m Carrier Uniport HP 80-100 mesh Column temperature: 150 ° C. → 320 ° C. Hold time: 1 min Heating rate: 15 ° C. / min Inlet temperature: 300 ° C Carry gas: Helium 50 ml / min Combustion gas: Air 0.5 kg / cm2 H2 0.6 kg / cm2 Detector: FID

Examples 2 and 3 Comparative Examples 1, 2 and 3 The catalysts and synthesis conditions were all used in the same manner as in Example 1 except that the catalysts and synthesis conditions were used as shown in Table 1, and the amount of the cyclic ester compound was measured. The results are also shown in Table 1.

[0035]

[Table 1]

Example 4 100 parts by weight of the lactone polyol obtained in Example 1 and 4,4'-diphenylmethane diisocyanate 40
The mixture was heated at 70 ° C. for 3 hours in a nitrogen atmosphere to obtain a prepolymer having an NCO group content of 6.5% by weight. On the other hand, 1,4-butanediol and trimethylolpropane were mixed at 60/40% by weight to obtain a curing agent.

NC was added to 140 parts by weight of the obtained prepolymer.
9.3 parts by weight of a curing agent was added so that the O group / OH group ratio became 1.05, mixed, and poured into a molding machine.
Subsequently, the sheet was cured by heating at 120 ° C. for 12 hours to obtain a sheet-shaped molded product having a thickness of 2 mm.

The physical properties of the obtained sheet-like molded product were evaluated according to the following methods. The results are shown in Table 2.

(A) Hardness The hardness (JIS A) was measured according to JIS-K6301. (B) Tensile strength and elongation at break In accordance with JIS-K6301, a tensile test was performed by an autograph using a dumbbell-shaped No. 3 test piece, and the tensile strength (MP
a) and elongation at break (%) were measured.

(C) The test specimen was left to mature at room temperature for 3 weeks,
The blooming state of the surface of the molded product was visually observed. ：: Blooming was not observed. Δ: Mottled pattern is slightly observed. ×: A powder blowing phenomenon or a mottled pattern is observed.

Examples 5 and 6 Comparative Examples 4, 5 and 6 Using a lactone-based polyol as shown in Table 2, a prepolymer having an NCO group content of 6.5% by weight was prepared in the same manner as in Example 4. After it was obtained, it was crosslinked with a curing agent and cured by heating. The physical properties of the obtained sheet-like molded product were similarly evaluated. The results are also shown in Table 2.

[0042]

[Table 2]

[0043]

According to the present invention, there is provided a method for producing a lactone-based polyol in which the total amount of the cyclic ester compound as a reaction by-product is 0.5% by weight or less. This makes it possible to provide a polyurethane resin having excellent physical properties and an effect of suppressing blooming on the surface of a molded product.

[0044]

[Brief description of the drawings]

FIG. 1 shows a gas chromatographic chart of a lactone polyol obtained in Example 1 of the present invention.

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 4J029 AA02 AB04 AC02 AD10 BA01 BA02 BA03 BA04 BA05 BA07 BA08 BA09 BA10 BF25 EG07 EG09 EG10 FC02 FC03 FC05 FC08 HA01 HE06 JA091 JB122 JB171 JB182 JC042 JC062 JC072J072 JE162 JF371 KE08 KE09 KE10 4J034 CA04 CA15 CA17 CB01 CB03 CB05 CB07 CC03 CC12 CC23 CC26 CC29 CC34 CC45 CC52 CC61 CC62 CC65 CD04 CD06 CE01 CE03 DA01 DB03 DB07 DF11 DF12 DF16 DF20 DF32 DH02 HC02 HC02 HC02 HC02 HC22 HC46 HC52 HC61 HC64 HC67 HC71 HC73 JA01 JA02 JA42

Claims (2)

[Claims] An organotin-based catalyst is added to an initiator having an active hydrogen comprising a polyhydric alcohol or a polyhydric amine.
In the presence of 001 to 0.001% by weight, the lactone monomer is subjected to a ring-opening polymerization reaction at a reaction temperature of 165 ° C to 175 ° C,
A lactone-based polyol obtained by terminating the reaction when the lactone monomer becomes 0.5% by weight or less, and a cyclic ester compound as a reaction by-product in the polyol is 0.5% by weight or less in total amount. A method for producing a lactone-based polyol. 2. A polyurethane resin using the lactone-based polyol obtained by the production method according to claim 1.