JP4156051B2 - Process for producing isocyanurate ring-containing polyisocyanates - Google Patents

Description

【００３５】
比較例１
助触媒ジ−ｎ−ブチルスズジラウレートを使用しない以外は実施例１と同様に反応を行ったが、イソシアヌレート化は進行せず、反応温度を１２０℃まで上げたところで急激な発熱が起こったため、停止剤として８５％リン酸０．２ｇを添加して反応を停止した。得られた反応マスには、三量体以上の多核体が多く生成していた。
【００３６】
比較例２
助触媒としてジ−ｎ−ブチルスズジラウレートのかわりにジ−ｎ−ブチルスズジクロライドを使用した以外は実施例１と同様に反応を行ったが、イソシアヌレート化は進行せず、反応温度を１２０℃まで上げたところで急激な発熱が起こったため、停止剤として８５％リン酸０．２ｇを添加して反応を停止した。得られた反応マスには、三量体以上の多核体が多く生成していた。
【００３７】
比較例３
助触媒ジ−ｎ−ブチルスズジオキシドを用いずに、界面活性剤であるベンジルトリメチルアンモニウムクロライド３．５ｇを用い、反応器内の温度を６０℃にした以外は実施例３と同様に反応を行ったところ、反応は進行し温度上昇もゆるやかであった。反応マスをろ過して、次いで薄膜蒸発缶によって未反応のモノマーを除去したところ、得られた生成物は白濁固体であった。
【００３８】
【発明の効果】
以上、本発明の特徴をまとめると、以下のとおりである。
（１）、触媒活性が高く、少量の触媒使用量で反応が進行する。
（２）、反応の制御性、再現性に優れている。
（３）、実質的に無色透明のイソシアヌレート環を有するポリイソシアナートが得られる。
かくして得られた無色透明のイソシアヌレート環を有するポリイソシアナートは耐候性、耐熱性に優れたポリウレタン原料として非常に有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a polyisocyanate having an isocyanurate ring useful as a curing agent when producing a polyurethane resin such as a polyurethane paint or a casting material.
[0002]
[Prior art and problems to be solved by the invention]
Polyisocyanates having an isocyanurate ring with excellent weather resistance, heat resistance, chemical resistance, etc. in the molecule are used as raw materials for polyurethanes such as paints, adhesives, elastomers, artificial leather, foams, and plastic lenses. The Regarding the production method, JP 54-119480, JP 55-49360, JP 2-33682, JP 61-129173, JP 2-110123, JP 2-250872, JP-A-2-6480, JP-A-2-32068, JP-A-2-64454, JP-A-1-297420, JP-A-1-149211, JP-A-61-111371, JP-A-60-181078, JP 60-181114, JP 2-11554, JP 2-107337, JP 55-143978, JP 52-17484, JP 61-227574, JP 57 -47319, JP 59-22916, JP 63-57577, JP 63-93770, JP 63-96178, JP 6-166777. Many patent applications have been made.
[0003]
The isocyanuration catalysts proposed by these patent applications include hydroxyalkyl group-containing quaternary ammonium hydroxides and organic weak acid salts, quaternary ammonium hydroxides and organic weak acid salts, aliphatic carboxylic acid alkali metal salts, aminosilyls Group-containing compounds, quaternary ammonium, phosphonium fluoride, and the like. However, these catalysts have the drawback that the resulting isocyanurate ring-containing polyisocyanate tends to be colored.
[0004]
On the other hand, Japanese Patent Publication No. 7-5573 discloses a method for producing an isocyanurate ring-containing polyisocyanate which does not cause coloring by using potassium fluoride as a catalyst. In US Pat. No. 5574, the use of a catalyst composed of one or a combination of two or more compounds selected from potassium fluoride and (1) polyethylene oxide compound (2) quaternary ammonium salt (3) phosphonium compound is small. It is described that an uncolored isocyanurate ring-containing polyisocyanate can be produced by using a catalyst and mild reaction conditions. However, even when phase transfer catalysts such as (1) to (3) are used in combination with potassium fluoride, the catalytic activity is still low and relatively high for aliphatic and / or alicyclic polyisocyanates. A reaction temperature was required. For this reason, it is difficult to control the reaction after the start of the isocyanuration reaction, and a polynuclear body having poor solubility is likely to be produced. These problems can be improved to some extent by increasing the amount of phase transfer catalyst such as (1) to (3) relative to potassium fluoride, but the isocyanurate ring-containing polyisocyanate produced when the amount of phase transfer catalyst increases. Undesirable because it adversely affects physical properties such as white turbidity in the natto. Therefore, there has been a demand for a method for producing a non-colored isocyanurate ring-containing polyisocyanate that can be more easily controlled.
[0005]
[Means for Solving the Problems]
As a result of intensive studies in view of these points, the present inventors have found that 1 of the compounds selected from (1) polyethylene oxide compound (2) quaternary ammonium salt (3) phosphonium compound together with potassium fluoride as a catalyst. It has been found that the reaction temperature of the isocyanurate formation can be greatly reduced by using a dialkyl tin compound as a co-catalyst when using a species or a combination of two or more species, and the present invention has been completed.
[0006]
That is, the present invention is a single-mer polyisocyanate, and / or 1 to 3 partially urethanized polyisocyanate with monofunctional alcohols Upon is isocyanurating, potassium fluoride with a catalyst (1) Polyethylene Using one or a combination of two or more compounds selected from oxide compounds, (2) quaternary ammonium salts, and (3) phosphonium compounds, and further using a dialkyltin compound as a co-catalyst , Dialkyltin compounds are dimethyltin diacetate, dibutyltin dioctanoate, dimethyltin dilaurate, di-n-butyltin dilaurate, di-n-butyltin di (2-ethylhexanoate), dibutyltin dibutoxide, dioctyltin dibutoxide, Dibutyltin di (thio Tokishido), di (2-ethylhexyl) tin oxide, dioctyl tin oxide, bis (butoxy dibutyltin) oxide, is at least one selected di -n- butyl tin oxide, and dibutyl Zusu sulfide, isocyanurate ring-containing polyisocyanates It is a manufacturing method.
[0009]
The present invention is characterized in that the dialkyl tin compound in the methods of the SL placement is di -n- Buchirusuzujira ULE over preparative.
[0010]
According to the present invention, in the method of the Symbol mounting is characterized in that monomeric polyisocyanate is an aliphatic and / or alicyclic polyisocyanate.
[0011]
According to the present invention, in the method of the SL placement, monomeric polyisocyanates 2,5- and / or 2,6-diisocyanate methyl bicyclo [2,2,1] heptane (NBDI), 1-isocyanato -3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDi), hexamethylene diisocyanate (HDi), 1,3-cyclohexyl diisocyanate, 1,4-cyclohexyl diisocyanate, 4,4 ' 1 type selected from the group consisting of methylenebis (cyclohexyl isocyanate), methyl-2,4-cyclohexanediisocyanate, methyl-2,6-cyclohexanediisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane or It is characterized by being a mixture of two or more.
[0012]
According to the present invention, in the method of the Symbol mounting, that the monomeric polyisocyanate is 2,5- and / or 2,6-diisocyanate methyl bicyclo [2,2,1] heptane (NBDI) It is a feature. According to the present invention, in the method of the SL placement, monomeric polyisocyanate and hexamethylene diisocyanate (HDi) 2,5-and / or 2,6-diisocyanate methyl bicyclo [2,2,1 ] It is characterized by being a mixture of heptane (NBDi).
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the monomer polyisocyanate used in the present invention include hexamethylene diisocyanate (HDi), 1-isocyanato-3,3,5, -trimethyl-5-isocyanatomethylcyclohexane (IPDi), 2,5 -And / or 2,6-diisocyanatomethylbicyclo [2,2,1] heptane (NBDi), 2,2,4- or 2,4,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate 2,6-diisocyanatomethylcaproate, 1,3-cyclohexyl diisocyanate, 1,4-cyclohexyl diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methyl-2,4-cyclohexanedi Isocyanate, methyl-2,6-cyclohexane diisocyanate, Aliphatic and / or alicyclic polyisocyanates such as 1,3-bis (isocyanatomethyl) cyclohexane, m- or p-xylylene diisocyanate, 1,3- or 1,4-tetramethylxylylene diisocyanate , 2,4- and / or 2,6-toluene diisocyanate (TDi), 2,4′- and / or 4,4′-diphenylmethane diisocyanate (MDi) and the like. It is done. These monomer polyisocyanates can be used in combination of two or more. Of these, aliphatic and / or alicyclic polyisocyanates are more preferred.
[0014]
Polyisocyanates partially urethanated with 1 to 3 functional alcohols are also preferably used as raw materials. Examples of 1 to 3 functional alcohols used here include, for example, methanol, ethanol, various butanols, 2-ethyl-hexanol, ethylene glycol, 1,2- or 1,3-propylene glycol, 1,3- or 1,4- or 2,3-butylene glycol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, trimethylolpropane, glycerin, 1,2,6-hexanetriol, etc. Examples thereof include low molecular weight compounds and polyester polyols and polyether polyols having a molecular weight of about 200 to 10,000.
[0015]
The NCO / OH equivalent ratio in the preliminary reaction of alcohol and monomer polyisocyanate is selected from a value of about 10 to 100 according to the purpose.
[0016]
The partial urethanization reaction and the isocyanuration reaction may or may not use a solvent, but when used, a solvent having no reaction activity with respect to the isocyanate group should be selected.
[0017]
Potassium fluoride used in the present invention can be used in various shapes such as pellets, powders, and flakes, but since it has low hygroscopicity and high activity, spray dried potassium fluoride (sd.KF) is used. Particularly preferred.
[0018]
Examples of the compounds (1) to (3) used in combination with potassium fluoride include polyethylene glycols such as polyethylene glycol, polyethylene glycol monomethyl ether and polyethylene glycol dimethyl ether, dibenzo-18 - crown-6 crown ether such as dicyclohexyl-18-crown-6, for example, Kanto chemical Co. cryptands such as C ₁₄ H ₂₈ N ₂ O ₄ is commercially available as [Kryptofix -111], etc. (2) quaternary ammonium salts such as benzyltriethylammonium chloride and tetrabutylammonium bromide, and (3) phosphonium compounds such as trioctylethylphosphonium bromide and tetrabutylphosphine. Examples thereof include honium chloride.
[0019]
In the method of the present invention, a dialkyltin compound cocatalyst is used in combination with a catalyst comprising potassium fluoride and the above compounds (1) to (3), and the amount of the catalyst itself is used without a cocatalyst. The amount that is less than the most effective amount may be used. In practice, the amount of potassium fluoride used is 0.000001 to 0.0005 parts by weight with respect to 1 part by weight of the monomer polyisocyanate and / or partially urethanized polyisocyanate used in the reaction. It is sufficient, preferably 0.000005 to 0.0002 parts by weight. The amount of the phase transfer catalyst (1) to (3) is preferably 1/100 to 100 times the amount of potassium fluoride. If the amount of catalyst is too small, it takes too much time to achieve the desired conversion, and it is not appropriate.If the amount of catalyst is too large, the isocyanuration reaction is too fast and involves a large exotherm, so reaction control is not possible. It becomes difficult.
[0020]
Specific examples of the dialkyltin compound used as a co-catalyst in the present invention include dialkyltin dicarboxylates such as dimethyltin diacetate, dibutyltin dioctanoate, dibutyltin dilaurate, dibutyltin dibutoxide, dioctyltin dibutoxide, etc. Dialkyltin dialkoxides, dialkyltin dithioalkoxides such as dibutyltin di (thiobutoxide), dialkyltin oxides such as di (2-ethylhexyl) tin oxide, dioctyltin oxide, bis (butoxydibutyltin) oxide, dibutyltin sulfide And dialkyl tin sulfides.
[0021]
Of these, dialkyltin dicarboxylates are preferable, and di-n-butyltin dilaurate is more preferable.
[0022]
In the present invention, dialkyltin halides such as dibutyltin dichloride and dimethyltin dichloride have almost no effect as a promoter.
[0023]
The amount of the cocatalyst used is preferably 1/10 to 10 times the amount of potassium fluoride used. When the amount is 1/10 or less, the effect of the cocatalyst is small. The nurate ring-containing polyisocyanate is not preferred because it may adversely affect physical properties such as cloudiness.
[0024]
In the present invention, there is no problem even if a compound generally known as an isocyanurate cocatalyst such as active hydrogen compounds such as alcohols and phenols, tertiary amines and phosphorous acid triesters is used.
[0025]
The catalyst and the co-catalyst may be added to the raw material monomer polyisocyanate and / or partially urethanized polyisocyanate, or may be added in advance by mixing.
[0026]
The isocyanuration reaction is usually performed at a temperature of 0 to 80 ° C, preferably 30 to 60 ° C.
[0027]
Especially when aliphatic and / or alicyclic polyisocyanates are used as monomer polyisocyanates and / or partially urethanized polyisocyanate raw materials, if a dialkyltin compound is not used as a co-catalyst, 100 ° C. or higher Although a sufficient reaction rate could not be obtained unless the reaction temperature was 1, the reaction proceeded sufficiently at a temperature around 30 to 80 ° C. by using a dialkyltin compound promoter. For this reason, reaction control became easy and it became possible to reduce the production amount of the poorly soluble polynuclear body.
[0028]
The progress of the reaction can be carried out by NCO titration, refractive index, viscosity, IR measurement and the like of the reaction solution. When the reaction reaches the desired conversion rate, the reaction is stopped by deactivating the catalyst by adding a terminator. It is appropriate to select this conversion rate in the range of 10 to 60%. If the conversion rate is 10% or less, the productivity is too bad, which is not preferable, and if the conversion rate is 60% or more, the high molecular weight oligomer component increases, and the physical properties of the resulting isocyanurate ring-containing polyisocyanate are not preferable. Examples of the reaction terminator include strong inorganic acids such as hydrochloric acid, phosphoric acid, and sulfuric acid, acidic organic substances such as benzoyl chloride and acidic phosphate esters, and adsorbing substances such as silica gel and acidic group-containing resins. The deactivated potassium fluoride is insolubilized in the reaction system, but can be easily removed by filtration because the amount used is small.
[0029]
Thus, after completion of the reaction at a conversion rate of monomer polyisocyanate and / or partially urethanized polyisocyanate to a product of 10 to 60%, unreacted monomer polyisocyanate is reacted from the reaction solution. When using a natto and a solvent, remove the solvent and purify. As a purification method, there are vacuum distillation, solvent extraction, and the like, but in general, a falling film evaporator is preferably used. From the viewpoint of safety and health for the human body, the content of the monomer polyisocyanate in the product isocyanurate ring-containing polyisocyanate must be 1.0% by weight or less.
[0030]
【Example】
Hereinafter, although an Example demonstrates concretely, the method of this invention is not limited by an Example.
Example 1
A four-necked flask equipped with a reflux condenser, a thermometer and a stirrer was charged with 1000 g of NBDi and 0.1 g of di-n-butyltin dilaurate, and the temperature was raised to 45 ° C. while stirring the reactor in a nitrogen stream. 0.1 g of potassium fluoride mixed in advance and 10 g of polyethylene glycol (PEG 400) having an average molecular weight of 400 were dropped over 3 hours. The temperature in the reactor gradually rose to 50 ° C. by the end of the dropping. Thereafter, the temperature was maintained for 1 hour, and then 0.2 g of 85% phosphoric acid was added as a terminator and further stirred for about 1 hour to completely stop the reaction. After cooling to room temperature, the deposited deactivated catalyst was removed by filtration. The reaction mass was colorless and transparent. The unreacted monomer was then removed with a thin film evaporator. The obtained product was a colorless and transparent solid at room temperature and had a melting point of 50 to 60 ° C., an NCO content of 18.4%, and a monomer content of 0.2%. The product yield was 380 g and the conversion from NBDi was 38%.
[0031]
Example 2
A four-necked flask equipped with a reflux condenser, a thermometer and a stirrer was charged with 1000 g of NBDi, 0.05 g of di-n-butyltin di (2-ethylhexanoate), and 1 g of triphenyl phosphite (TPP). Under a stream of air, the temperature inside the reactor was increased to 60 ° C. while stirring, and 0.03 g of potassium fluoride and 10 g of polyethylene glycol (PEG 400) having an average molecular weight of 400 were added dropwise over 3 hours. The temperature in the reactor gradually increased to 68 ° C. by the end of the dropping. Then, after maintaining the temperature for 0.5 hour, 0.2 g of 85% phosphoric acid was added as a terminator and further stirred for about 1 hour to completely stop the reaction. After cooling to room temperature, the deposited deactivated catalyst was removed by filtration. The reaction mass was colorless and transparent. The unreacted monomer was then removed with a thin film evaporator. The obtained product was a colorless and transparent solid at room temperature and had a melting point of 50 to 60 ° C., an NCO content of 18.0%, and a monomer content of 0.3%. The product yield was 400 g and the conversion from NBDi was 40%.
[0032]
Example 3
A four-necked flask equipped with a reflux condenser, a thermometer, and a stirrer was charged with 1000 g of NBDi, 0.1 g of dibutyltin dibutoxide, and 2 g of triphenyl phosphite. The temperature was raised, and 0.03 g of potassium fluoride and 10 g of polyethylene glycol (PEG 400) having an average molecular weight of 400 were added in advance. The temperature in the reactor gradually increased to 55 ° C., maintained for a while, and then gradually decreased to 30 ° C. Two hours after the start of exotherm, 0.1 g of 85% phosphoric acid was added as a terminator, and then the mixture was further stirred for about 1 hour to completely stop the reaction. After cooling to room temperature, the deposited deactivated catalyst was removed by filtration. The reaction mass was colorless and transparent. The unreacted monomer was then removed with a thin film evaporator. The obtained product was a colorless and transparent solid at room temperature and had a melting point of 50 to 60 ° C., an NCO content of 18.3%, and a monomer content of 0.2%. The product yield was 430 g and the conversion from NBDi was 43%.
[0033]
Examples 4-6
A polyisocyanate having an isocyanurate ring was obtained in the same manner as in Example 2 under the formulation and conditions shown in Table 1. The physical properties of the obtained product are summarized in the lower column of Table 1.
[0034]
[Table 1]

[0035]
Comparative Example 1
The reaction was carried out in the same manner as in Example 1 except that the co-catalyst di-n-butyltin dilaurate was not used, but the isocyanurate formation did not proceed, and a sudden exotherm occurred when the reaction temperature was raised to 120 ° C. The reaction was stopped by adding 0.2 g of 85% phosphoric acid as an agent. In the obtained reaction mass, a large number of polynuclear bodies of trimer or higher were generated.
[0036]
Comparative Example 2
The reaction was carried out in the same manner as in Example 1 except that di-n-butyltin dichloride was used instead of di-n-butyltin dilaurate as a cocatalyst. However, the isocyanurate formation did not proceed and the reaction temperature was raised to 120 ° C. Since sudden heat generation occurred, the reaction was stopped by adding 0.2 g of 85% phosphoric acid as a stopper. In the obtained reaction mass, a large number of polynuclear bodies of trimer or higher were generated.
[0037]
Comparative Example 3
The reaction was carried out in the same manner as in Example 3 except that 3.5 g of benzyltrimethylammonium chloride as a surfactant was used without using the cocatalyst di-n-butyltin dioxide and the temperature in the reactor was changed to 60 ° C. As a result, the reaction proceeded and the temperature rise was slow. The reaction mass was filtered and then the unreacted monomer was removed with a thin film evaporator. The resulting product was a cloudy solid.
[0038]
【The invention's effect】
The characteristics of the present invention are summarized as follows.
(1) The catalyst activity is high, and the reaction proceeds with a small amount of catalyst used.
(2) Excellent reaction controllability and reproducibility.
(3) A polyisocyanate having a substantially colorless and transparent isocyanurate ring is obtained.
The polyisocyanate having a colorless and transparent isocyanurate ring thus obtained is very useful as a polyurethane raw material having excellent weather resistance and heat resistance.

Claims (6)

(1) Polyethylene oxide compound (2) together with potassium fluoride as a catalyst for the isocyanuration of monomeric polyisocyanate and / or polyisocyanate partially urethanated with 1-3 functional alcohols ) quaternary ammonium salt, (3) using one or a combination of two or more phosphonium compounds from the compound chosen, characterized by using the dialkyl tin compound as further cocatalyst, the dialkyl tin compound , Dimethyltin diacetate, dibutyltin dioctanoate, dimethyltin dilaurate, di-n-butyltin dilaurate, di-n-butyltin di (2-ethylhexanoate), dibutyltin dibutoxide, dioctyltin dibutoxide, dibutyltin di (thio) Butoxide), di ( - ethylhexyl) tin oxide, dioctyl tin oxide, bis (butoxy dibutyltin) oxide, is at least one selected di -n- butyl tin oxide, and dibutyl Zusu sulfide method isocyanurate ring-containing polyisocyanates. The method according to claim 1, wherein the dialkyl tin compound is a di -n- Buchirusuzujira ULE over preparative. The monomeric polyisocyanate aliphatic and / or manufacturing process according to claim 1 or 2, wherein the alicyclic polyisocyanate. The monomer polyisocyanate is 2,5- and / or 2,6-diisocyanatomethylbicyclo [2,2,1] heptane (NBDi), 1-isocyanato-3,3,5-trimethyl-5- Isocyanatomethylcyclohexane (IPDi), hexamethylene diisocyanate (HDi), 1,3-cyclohexyl diisocyanate, 1,4-cyclohexyl diisocyanate, 4,4′-methylenebis (cyclohexyl isocyanate), methyl-2 , 4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, or a mixture of two or more thereof. 2. The production method according to 2 or 3 . The method according to claim 4, wherein the monomer polyisocyanate is 2,5- and / or 2,6-diisocyanatomethylbicyclo [2,2,1] heptane (NBDi). The monomeric polyisocyanate is a mixture of hexamethylene diisocyanate (HDi) and 2,5- and / or 2,6-diisocyanatomethylbicyclo [2,2,1] heptane (NBDi). 4 the method according.