JP5121085B2 - Method for producing lactone-based polyol and polyurethane resin using the same - Google Patents

Description

【００３４】
実施例２、３ 比較例１、２、３
触媒、合成条件を表１に示したとおり用いる以外は全て実施例１と同様の方法で合成し、環状エステル化合物の量を測定した。結果を同じく第１表に示した。
【００３５】
【表１】

【００３６】
実施例４
実施例１で得られたラクトン系ポリオール１００重量部、４，４’−ジフェニルメタンジイソシアネート４０重量部を仕込み、窒素雰囲気中で７０℃３時間加熱反応させ、ＮＣＯ基の含有率が６．５重量％のプレポリマーを得た。他方、１，４−ブタンジオールとトリメチロールプロパンを６０／４０重量％で混合して硬化剤を得た。
【００３７】
得られたプレポリマー１４０重量部にＮＣＯ基／ＯＨ基比が１．０５になるよう硬化剤９．３重量部添加し、混合し、成形機に注入し、８０℃×２時間、つづいて１２０℃×１２時間の条件で加熱硬化させ、厚さ２ｍｍのシート状成形物を得た。
【００３８】
得られたシート状成形物において以下の方法に従って物性を評価した。
表２に示した。
【００３９】
（Ａ）硬度 ＪＩＳ−Ｋ６３０１に準拠して硬度（ＪＩＳ Ａ）を測定した。
（Ｂ）引張強度および切断時の伸び
ＪＩＳ−Ｋ６３０１に準拠し、ダンベル状３号試験片を用いて
オートグラフで引張試験を行い、引張強度（ＭＰａ）および切断
時の伸び（％）を測定した。
【００４０】
（Ｃ）試験片を常温で３週間放置熟成し、成形物表面のブルーミング状態を
目視にて観察した。
○：ブルーミング見られない。
△：わずかにまだら模様が見られる。
×：粉吹き現象またはまだら模様が見られる。
【００４１】
実施例５，６ 比較例４、５、６
表２にしめしたとおりのラクトン系ポリオールを用いて実施例４と同様の方法にてＮＣＯ基含有率 ６．５重量％のプレポリマーを得た後、硬化剤にて架橋し、加熱硬化させた。得られたシート状成形物を同様に物性評価した。結果を同じく表２に示した。
【００４２】
【表２】

【００４３】
【発明の効果】
本発明は、その反応副生成物である環状エステル化合物が、トータル量で０．５重量％以下であるラクトン系ポリオールを製造する方法を提供するものであり、それを用いたことにより、優れた物性、成形物表面へのブルーミング現象の抑制効果を有するポリウレタン樹脂を提供することができる。
【００４４】
【図面の簡単な説明】
【図１】本発明の実施例１で得られたラクトンポリオールのガスクロマトグラフのチャートを示すものである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a lactone-based polyol for a polyurethane resin material in which the total amount of cyclic ester compounds as reaction by-products is 0.5% by weight or less, and prevention of deterioration of physical properties using the same, molding surface The present invention provides a urethane resin that solves problems such as suppression of blooming phenomenon and thread breakage.
[0002]
[Prior art]
Lactone-based polyols are used in many fields in terms of differences in average molecular weight, number of functional groups, and resistance to hydrolysis. For example, lactone-based polyols obtained by ring-opening polymerization of ε-caprolactone using polyhydric alcohols as initiators are very useful as raw materials for polyurethane resins, and are transported using their excellent physical properties and elasticity. It is used for elastomers such as industrial belts, blades for copying machines, urethane fibers and various industrial chips.
[0003]
Such a lactone-based polyol is 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, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pb, Pb, Sr, Zr, Pd, Metal chlorides such as Sn, oxides, hydroxides, fatty acid metal salts such as acetic acid, oxalic acid, octylic acid, lauric acid, naphthenic acid of the above metals, sodium methylate, sodium ethylate, aluminum tetraisopropoxide All commonly used catalysts such as alcoholates such as isopropyl titanate and n-butyl titanate, phenolates such as sodium phenolate, organometallic compounds of metals such as Al, Ti, Zn, Zr, Sn, and Pb are used. It is known.
[0005]
However, when synthesizing these lactone-based polyols, the generation of reaction by-products cannot be avoided, and there are always a small amount of cyclic ester compounds such as dimers, trimers, tetramers and pentamers of lactone monomers. Generate. These have a cyclic structure and do not have active hydrogen such as a hydroxyl group capable of reacting with isocyanate.
[0006]
Lactone polyols are usually solid at room temperature, and when formed into urethane resin moldings such as rollers and blades, over time, blooming occurs on the surface of the moldings, and molds used for molding urethane resins. Dirt may be caused, and workability at the time of manufacture may be remarkably deteriorated. This is thought to be because by-products remain in the resin when the lactone polyol and isocyanate are reacted to obtain a urethane resin. For example, in JP-A-10-310636, the lactone dimer content is reduced. A process for producing a lactone-based polyol that can be produced is proposed.
[0007]
However, according to the knowledge obtained by the present inventors, the problem of lowering the strength of the urethane resin could not be solved only by reducing the lactone dimer content. Was rather a trimer, a tetramer, or a pentamer, and was found not to originate only from a lactone dimer. It was found that the above-mentioned problems including strength reduction should be considered to be the total content of the cyclic ester compound present in the lactone polyol. Therefore, the present inventors have studied a method for producing a lactone-based polyol that can reduce the total content of the cyclic ester compound.
[0008]
[Problems to be solved by the invention]
That is, an object of the present invention is to provide a method for producing a lactone-based polyol for a polyurethane resin raw material that can produce a polyurethane resin that does not cause a blooming phenomenon on the surface of the molded product without causing deterioration in physical properties of the molded product, and a polyurethane resin using the same. is there.
[0009]
[Means for Solving the Problems]
As a result of intensive studies to achieve these objects, the present inventors have determined that the total content of the cyclic ester compound is 0.00 by polymerizing a lactone with a specific catalyst, a specific reaction temperature, and a specific reaction condition. The inventors found that a lactone-based polyol having a content of 5% by weight or less was obtained and completed the present invention.
[0010]
That is, the present invention, the amount of the polyhydric alcohol or polyhydric using an initiator having an active hydrogen consisting of amines, tin octylate or dibutyltin oxide or dibutyltin dilaurate an organic tin catalyst is 1 for feedstock -10 ppm, the lactone monomer was subjected to a ring-opening polymerization reaction at a reaction temperature of 165 ° C. to 175 ° C., and when the lactone monomer was 0.5 wt% or less, the reaction was terminated, and immediately cooled to 100 ° C. or less, by terminating the polymerization reaction, a cyclic ester compound reaction by-products in the polyol is a method of manufacturing a lactone-based polyol, characterized in that to obtain a lactone-based polyol is 0.5 wt% or less in total amount It is to provide. Further, there is provided an excellent poly urethane resin The strength property decrease by using a polyurethane resin for lactone polyol, allowing the blade suppression and prevent thread breakage.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
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, enanthlactone, dodecanolactone and the like.
One or more of these monomers can be used as a mixture.
[0012]
As the initiator of the present invention, any other compound may be used as long as it is a polyhydric alcohol or an amine and 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-methyl 1,5-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, glycerin, trimethylolpropane, trimethyloloctane, Examples thereof include polyols such as pentaerythritol.
[0013]
Examples of the polyvalent amine include low-molecular polyamines such as ethylenediamine and hexaethylenediamine, and low-molecular alkanolamines such as ethanolamine. In addition, polyoxypropylene glycol, polyoxybutylene glycol, polytetramethylene glycol, acrylic polyol, styrene allyl alcohol copolymer, polyester polyol and the like having a hydroxyl group at the terminal can also be used as an initiator. These can be used alone or in combination of two or more.
[0014]
The catalyst of the present invention, for example, tin octylate, dibutyltin oxide, and dibutyltin dilaurate. Inorganic tin catalysts are more active 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 thereof causes the polymerization reaction to progress and the generation of a cyclic ester compound, which increases, and therefore an organotin catalyst is more preferable.
[0015]
The amount of the catalyst used is 1 ppm to 10 ppm ( 0.0001 to 0.001% by weight) with respect to the charged raw material. When the amount of catalyst is less than 1 ppm, the reaction rate is slow. On the other hand, when the amount exceeds 10 ppm, not only the hydrolysis resistance of the lactone polyol or urethane resin using the same deteriorates, but also the hue and thermal stability deteriorate. It is not preferable.
[0016]
The reaction method may be any commonly used lactone ring-opening polymerization method, and any of bulk polymerization, solution polymerization, suspension polymerization and the like may be used. A bulk polymerization method is preferred.
[0017]
The reaction temperature of the present invention is 165 ° C to 175 ° C. 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 industrially. On the other hand, when the reaction temperature is higher than 175 ° C., it may cause coloring due to the oxidation reaction, the reaction is too fast, and the generation rate of the cyclic ester compound is increased, and the cyclic ester compound is reduced to 0.5% by weight or less. This makes it difficult to control when trying to terminate the reaction.
[0018]
The reaction is terminated when the lactone monomer becomes 0.5% by weight or less. When the ring-opening addition polymerization reaction is carried out, the residual amount of the lactone monomer in the system gradually decreases and becomes almost level. This is because the cyclic ester compound increases as the reaction continues. The reaction time is preferably 8 to 12 hours, the time when the residual monomer amount becomes 0.5% by weight or less is taken as the reaction end point, and immediately cooled to 100 ° C. or less to complete the polymerization reaction. If an unnecessary heat history is applied after the end of the reaction, the amount of the cyclic ester compound is gradually increased due to the transesterification regardless of the catalyst and reaction conditions.
[0019]
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 thereof is preferably dimer: 0.02-0.08% by weight, trimer: 0.0. 05-0.12% by weight, tetramer: 0.02-0.08% 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. However, if it exceeds 0.5% by weight, these problems may occur. In order to overcome this problem, post-treatment is required to reduce the cyclic ester compound, which is very inefficient in operation.
[0020]
The method for measuring the content of the cyclic ester compound is carried out by a gas chromatograph measuring device according to the gas chromatography conditions and analysis methods described in the examples. In particular, when the molecular weight is relatively large such that the molecular weight exceeds 1000, it is desirable to perform the following pretreatment. A lactone polyol is dissolved in a solvent containing an internal standard, extracted with hexane, a lactone polyol is precipitated, and a cyclic ester compound is extracted into a hexane layer. This can be measured by gas chromatography, and the amount of the cyclic ester compound contained in the lactone 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.
[0021]
The polyurethane resin of the present invention can be obtained by a conventionally known method such as a one-shot method or a prepolymer method using a lactone-based polyol and an organic polyisocyanate obtained by the above-described method and, if necessary, a chain extender. it can.
[0022]
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, dicyclohexylmethane diisocyanate, tridendiisocyanate, 1,5-na Examples include phthalene diisocyanate and crude diphenylmethane diisocyanate. Polyisocyanates may be used alone or in combination.
[0023]
Moreover, in the synthesis | combination of a polyurethane resin, although the low molecular compound which has two or more active hydrogen may be normally used as a chain extender, these active hydrogen compounds can also be used in this invention.
[0024]
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-cyclohexanediol, bis Diols such as (β-hydroxyethyl) terephthalate and xylene glycol, water, hydrazine, ethylenediamine, isophoronediamine, piperazine, phenylenediamine, tolylenediamine, adipic acid dihydrazide, isophthalic acid dihydrazide, and the like. You may use individually or in mixture. Furthermore, monovalent low molecular alcohol, low molecular diamine, etc. can also be used as a modifier | denaturant as needed.
[0025]
The catalyst used in the present invention may be a commonly used catalyst when producing polyurethane. For example, an amine compound, an organometallic compound, or an imidazole compound may be used.
[0026]
In addition to lactone-based polyols, polyols usually used for urethane resins such as polyester polyols such as polyoxyalkylene polyols, acrylic polyols, polybutadiene polyols, and adipates can be mixed without departing from the scope of the present invention. You may use.
[0027]
In addition to the above-described blending components, flame retardants, fillers, antistatic agents, colorants and the like can be added according to required performance without departing from the object of the present invention.
[0028]
With respect to the production method for obtaining a polyurethane resin using the above raw materials, a known urethanization reaction technique is used. For example, after a polyol and a low molecular weight compound having active hydrogen are mixed and preheated to about 40 to 100 ° C., an amount of polyisocyanate in such a ratio that the ratio of the active hydrogen number to the NCO group of these compounds is 1: 1. A solid-phase polymerization method in which a compound is added and stirred vigorously for a short time, and then allowed to stand at about 50 to 150 ° C. Furthermore, a polyol and polyisocyanate can be reacted in advance to obtain a polyurethane prepolymer, and then this polyurethane prepolymer can be reacted with a chain extender. The polyisocyanate compound is used in a slight excess because it is usually affected by moisture. These reactions may be a solution reaction method in which the reaction is carried out in a solvent composed of one or more of dimethylformamide, diethylformamide, dimethylsulfoxide, dimethylacetamide, tetrahydrofuran, methyl ethyl ketone, benzene, toluene, trichrene and the like. In this case, when the concentration is within the range of 10 to 40% by weight, it is preferable to obtain a high molecular weight polyurethane resin.
[0029]
【Example】
Hereinafter, the present invention will be specifically described by way of examples, but is not limited thereto. In the text, “parts” and “%” indicate weight standards unless otherwise specified.
[0030]
Example 1
A 1-liter four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a condenser was charged with 31 g of diethylene glycol, 947 g of ε-caprolactone and 0.005 g of stannous octylate as a catalyst while stirring under nitrogen. The reaction was carried out at 0 ° C. and sampled every 2 hours.
[0031]
<Analysis method>
Put 1 g of lactone polyol in a test tube with a lid, add an internal standard solution (diisobutyl phthalate / tetrahydrofuran: 20 g / l) accurately with a 0.5 ml pipette and dissolve while warming in a warm bath. Subsequently, 2.5 ml of n-hexane is added and vigorously stirred and mixed with a micro spatula to precipitate a lactone polyol. At this time, the internal standard diisobutyl phthalate and the low molecular cyclic lactone are extracted in the n-hexane layer.
[0032]
The n-hexane layer was measured with a gas chromatograph manufactured by Shimadzu Corporation under the following gas chromatographic conditions, and the amount of the lactone monomer and the amount of the cyclic ester compound in the lactone polyol were determined from a calibration curve measured in advance. After 10 hours, the residual amount of lactone monomer was 0.12% by weight, and the reaction was completed. The gas chromatograph chart at this time is shown in FIG. 1, and the amount of the cyclic ester compound is shown in Table 1.
[0033]

[0034]
Examples 2, 3 Comparative Examples 1, 2, 3
Except for using the catalyst and synthesis conditions as shown in Table 1, all were synthesized in the same manner as in Example 1, and the amount of the cyclic ester compound was measured. The results are also shown in Table 1.
[0035]
[Table 1]

[0036]
Example 4
100 parts by weight of the lactone-based polyol obtained in Example 1 and 40 parts by weight of 4,4′-diphenylmethane diisocyanate were charged and reacted by heating at 70 ° C. for 3 hours in a nitrogen atmosphere, so that the NCO group content was 6.5% by weight. Of a prepolymer was obtained. On the other hand, 1,4-butanediol and trimethylolpropane were mixed at 60/40% by weight to obtain a curing agent.
[0037]
9.3 parts by weight of a curing agent is added to 140 parts by weight of the obtained prepolymer so that the NCO group / OH group ratio is 1.05, mixed, poured into a molding machine, 80 ° C. × 2 hours, and then 120 It was heat-cured under the condition of ° C. × 12 hours to obtain a sheet-like molded product having a thickness of 2 mm.
[0038]
The physical properties of the obtained sheet-like molded product were evaluated according to the following methods.
It is shown in Table 2.
[0039]
(A) Hardness 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 with an autograph using a dumbbell-shaped No. 3 test piece, and tensile strength (MPa) and elongation at break (%) were measured. .
[0040]
(C) The test piece was aged for 3 weeks at room temperature, and the blooming state of the surface of the molded product was visually observed.
○: Blooming is not seen.
Δ: Slight mottled pattern is observed.
X: A powder blowing phenomenon or a mottled pattern is observed.
[0041]
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 obtained in the same manner as in Example 4, then crosslinked with a curing agent and heat-cured. . 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]
【Effect of the invention】
The present invention provides a method for producing a lactone-based polyol in which the cyclic ester compound, which is a reaction by-product, is 0.5% by weight or less in total amount, and by using it, the present invention is excellent. A polyurethane resin having an effect of suppressing physical properties and blooming phenomenon on the surface of the molded product can be provided.
[0044]
[Brief description of the drawings]
FIG. 1 shows a gas chromatograph chart of a lactone polyol obtained in Example 1 of the present invention.

Claims (1)

Using an initiator having active hydrogen consisting of polyhydric alcohol or polyamine, the amount of tin octylate or dibutyltin oxide or dibutyltin dilaurate used as the organotin catalyst is 1 to 10 ppm relative to the charged raw material, and lactone The monomer is subjected to a ring-opening polymerization reaction at a reaction temperature of 165 ° C. to 175 ° C., and the time when the lactone monomer becomes 0.5% by weight or less is regarded as the reaction end point, and immediately cooled to 100 ° C. or less to complete the polymerization reaction. Accordingly, the cyclic ester compound reaction by-products in the polyol method of producing a lactone-based polyol, characterized in that to obtain a lactone-based polyol is below 0.5 wt% in total amount.

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