New organotitanium compound, its production method and curing catalyst

Abstract

Provided are a novel organic titanium compound and curing catalyst that, by being added to a room temperature curable organopolysiloxane composition, are capable of quickly curing the composition, maintaining the storage stability thereof without damaging the same, and improving the adhesiveness of the cured product of the composition especially after soaking in warm water. Provided is an organic titanium compound that is a reaction product of: a fatty acid ester of a polyhydric alcohol; and an organic titanium compound that has a chelating ligand and an organooxy group and that are represented by the average composition formula (I): Ti(OR)4-a(X)a (where "R" is a substituted or unsubstituted monovalent hydrocarbon group having 1-12 carbon atoms, "X" is a chelating ligand, and "a" is number from 0.1-3.5).

Description

[Technical field]

[0001] The present invention relates to a novel organotitanium compound useful as a curing catalyst for room-temperature-curable resin compositions, and to a curing catalyst comprising said organotitanium compound. [Background technology]

[0002] Conventionally, room-temperature curable resin compositions such as room-temperature curable organopolysiloxane compositions have been known as curable resin compositions that undergo a condensation reaction with moisture (humidity) in the air at room temperature (23°C±15°C) to crosslink and cure to give an elastomer elastic body (rubber cured product). These room-temperature curable resin compositions are widely used in the fields of construction, transportation, electrical and electronic parts, etc., due to their safety, durability as rubber, and excellent adhesive properties. Adhesion in particular is often considered important, as it is closely related to the reliability of the components in which they are used.

[0003] Among room temperature curable organopolysiloxane compositions, so-called one-component (one-liquid) room temperature curable organopolysiloxane compositions do not require the trouble of weighing and mixing a base polymer, a crosslinking agent, a catalyst, etc. immediately before use, and are free of the risk of mistakes in compounding. In addition, even when a primer is not generally used, they have excellent adhesion to a wide range of substrates, and are therefore widely used as elastic adhesives and coating materials in the electrical and electronics industries, as well as construction sealants, etc. Such one-component room temperature curable organopolysiloxane compositions are often classified according to the compounds released from the composition when they come into contact with moisture in the air, and representative examples include deacetic acid type, deoxime type, deamide type, dehydroxylamine type, deacetone type, and dealcohol type organopolysiloxane compositions. Among these, dealcohol-removing organopolysiloxane compositions that harden by releasing alcohol are particularly preferred for their low odor, lack of corrosion to metals such as copper and iron, excellent self-adhesion (adhesion after hardening to various substrates when no primer is used), and excellent adhesive durability.

[0004] However, although one-component, alcohol-free organopolysiloxane compositions have the above-mentioned excellent properties for a short period after production, they have drawbacks in terms of storage stability, such as losing the properties they have immediately after production over time during storage, depending on the formulation. Furthermore, after storage in a high-temperature environment exceeding 50°C, which often occurs when the composition is stored in direct sunlight at the site of use or in a container during transportation, not only does the composition lose the properties it has immediately after production even after a relatively short period of storage, but it also suffers from problems such as poor curing.

[0005] One-component, dealcohol-removing organopolysiloxane compositions have been proposed for a long time, and a representative example of such a composition is a composition comprising a terminally hydroxyl-blocked organopolysiloxane, an alkoxysilane, and a titanium compound (Patent Document 1). Recently, it has been disclosed that a composition further containing a polyhydric alcohol fatty acid ester, such as triacetin, in addition to the room temperature curable organopolysiloxane composition disclosed in Patent Document 1 gives a cured product with excellent adhesion without the use of a primer, and has excellent storage stability in a sealed packaged form (Patent Document 2).In addition, Patent Document 3 discloses that the storage stability is improved by adding an organosilicon compound having a polyhydric alcohol fatty acid ester structure, such as triacetin, to a room temperature curable organopolysiloxane composition. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 39-27643 [Patent Document 2] Patent No. 4775600 [Patent Document 3] Patent No. 6690704 Summary of the Invention [Problem to be solved by the invention]

[0007] However, even when the polyhydric alcohol fatty acid ester disclosed in Patent Document 2 or the organosilicon compound having a polyhydric alcohol fatty acid ester structure disclosed in Patent Document 3 is used, the adhesion is not necessarily sufficient, and there remains a problem with the adhesion under hot water immersion conditions in particular. Accordingly, an object of the present invention is to provide an organotitanium compound that, when added to a room temperature curable organopolysiloxane composition such as a so-called silicone RTV rubber composition, can rapidly cure the composition while maintaining its storage stability without impairing it, and can also improve the adhesion of the cured product of the composition, particularly after immersion in hot water, as well as a method for producing the same and a curing catalyst. [Means for solving the problem]

[0008] As a result of intensive research conducted by the present inventors in order to achieve the above object, they have found that the organotitanium compounds shown below are useful for solving the above problems, and have completed the present invention.

[0009] That is, the present invention provides the following organotitanium compound and curing catalyst. [1] Average composition formula (I):Ti(OR) 4-a (X) a (In the formula, R is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms, X is a chelating ligand, and a is a number from 0.1 to 3.5.) 2. An organotitanium compound which is a reaction product of an organotitanium compound having an organoxy group represented by the formula (I) and a chelating ligand, and a fatty acid ester of a polyhydric alcohol. [2] The organotitanium compound according to [1], wherein, in the average composition formula (I), the organoxy group represented by OR is an alkoxy group. [3] The organic titanium compound according to [1] or [2], wherein the chelating ligand is a β-ketoester chelate or a β-diketone chelate. [4] The organic titanium compound according to any one of [1] to [3], wherein the chelating ligand is ethyl acetoacetate chelate (ethylacetoacetonato) or acetylacetone chelate (acetylacetonato). [5] The organic titanium compound according to any one of [1] to [4], wherein the fatty acid ester of a polyhydric alcohol is a fatty acid ester of ethylene glycol, propylene glycol, glycerol or pentaerythritol. [6] The organic titanium compound according to any one of [1] to [5], wherein the fatty acid ester of a polyhydric alcohol is at least one selected from the group consisting of triacetin, diacetin and monoacetin. [7] The organotitanium compound according to any one of [1] to [6], which is a reaction product of an organotitanium compound (I) having an organoxy group represented by average composition formula (I) and a chelating ligand and a fatty acid ester of a polyhydric alcohol, in a molar ratio of [organotitanium compound (I)]:[polyhydric alcohol fatty acid ester]=1:0.1 to 1:3.5. [8] A curing catalyst for a room-temperature curable resin composition, comprising the organotitanium compound according to any one of [1] to [7].

[0010] As for the organotitanium compounds of the present invention defined above, so long as the average structure of the organotitanium compounds as a group falls within the above range, the group is included in the present invention even if there are differences in structure between the individual organotitanium compounds.

[0011] The present invention also provides a curing catalyst for room temperature curable resin compositions, which comprises the above organotitanium compound. Effect of the Invention

[0012] The novel organotitanium compound of the present invention, when added to room temperature curable organopolysiloxane compositions such as so-called silicone RTV rubber compositions, contributes to the storage stability of the composition in an uncured state, and can rapidly crosslink and cure the composition through a condensation curing reaction in the presence of moisture (humidity) in the air at room temperature (23°C±15°C) to give a silicone elastomer elastic body (cured silicone rubber product). In particular, it can improve the adhesiveness of the cured silicone rubber product after immersion in warm water, making it useful as a curing catalyst for room temperature curable organopolysiloxane compositions (silicone RTV rubber compositions). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention will be described in detail below, but the present invention is not limited thereto.

[0014] <Organotitanium compounds> The organotitanium compound of the present invention has the average composition formula (I): Ti(OR) 4-a (X) a The compound is a reaction product of an organotitanium compound (I) having an organoxy group such as an alkoxy group and a chelating ligand, represented by the formula:

[0015] In the above average composition formula (I), examples of the substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms represented by R include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, and dodecyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; vinyl groups, allyl groups, propenyl groups, isopropenyl groups, butenyl groups, pentenyl groups, hexenyl groups, cyclohexyl groups, and the like. Examples of R include alkenyl groups such as nyl groups; aryl groups such as phenyl groups, tolyl groups, xylyl groups, and α-, β-naphthyl groups; aralkyl groups such as benzyl groups, 2-phenylethyl groups, and 3-phenylpropyl groups; and groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as F, Cl, and Br, cyano groups, and alkoxy groups such as methoxy and ethoxy groups, for example, 3-chloropropyl groups, 3,3,3-trifluoropropyl groups, 2-cyanoethyl groups, methoxymethyl groups, methoxyethyl groups, ethoxymethyl groups, and ethoxyethyl groups. Among these, R is preferably an alkyl group such as a methyl group, an ethyl group, an isopropyl group, or a tert-butyl group, and particularly preferably an isopropyl group or a tert-butyl group. In the above average composition formula (I), examples of the monovalent group (organooxy group) represented by OR include alkoxy groups, cycloalkoxy groups, alkenyloxy groups, aryloxy groups, aralkyloxy groups, and alkoxy-substituted alkoxy groups corresponding to the substituted or unsubstituted monovalent hydrocarbon groups having 1 to 12 carbon atoms exemplified as R. Among these, alkoxy groups such as methoxy group, ethoxy group, isopropoxy group, butoxy group, isobutoxy group, sec-butoxy group, and tert-butoxy group are preferred, and particularly isopropoxy group and tert-butoxy group are preferred.

[0016] In the above average composition formula (I), the chelating ligand represented by X includes acetoacetate esters such as methyl acetoacetate and ethyl acetoacetate, β-ketoester chelating ligands such as methyl pivaloyl acetate, methyl isobutyroyl acetate, ethyl benzoyl acetate, and methyl caproyl acetate, and β-diketone chelating ligands such as acetylacetone, 3,5-heptanedione, dipivaloylmethane, trifluoroacetylacetone, hexafluoroacetylacetone, 1-phenyl-1,3-butanedione, and 1,3-diphenyl-1,3-propanedione. Among these, ethyl acetoacetate chelate (ethyl acetoacetonate) and acetylacetone chelate (acetylacetonate), which are easily available, are preferred, and ethyl acetoacetate chelate (ethyl acetoacetonate) is particularly preferred.

[0017] In the above average composition formula (I), the average coordination number a of the chelating ligand for titanium is 0.1 to 3.5, more preferably 0.5 to 2.5, and particularly preferably 1.0 to 2.0.

[0018] The fatty acid ester of a polyhydric alcohol may be a compound in which a part or all (one or more) alkoxy groups in a polyhydric alcohol molecule form an ester with a fatty acid. Examples of the fatty acid ester of a polyhydric alcohol include ethylene glycol derivatives (fatty acid esters of ethylene glycol) such as ethylene glycol diacetate; propylene derivatives (fatty acid esters of propylene glycol) such as propylene glycol diacetate; triacetin (triacetylglycerin, glycerin triacetate), diacetin (diacetylglycerin, glycerin diacetate), monoacetin (diacetylglycerin, glycerin diacetate), and the like. Examples of suitable glycerol derivatives (fatty acid esters of glycerol) include glycerin (monoacetylglycerin, glycerin monoacetate), tributyrin, tricaprylin, tristearin, glycerol diacetate laurate, trimethylolpropane tristearate, and trimethylolpropane triacetate; and pentaerythritol derivatives (fatty acid esters of pentaerythritol) such as pentaerythritol monoacetate. From the viewpoints of availability and the molecular weight of the resulting organic titanium compound, however, triacetin, diacetin, and monoacetin are preferred, and triacetin is particularly preferred.

[0019] <Method of producing organotitanium compound> The organotitanium compound of the present invention can be produced, for example, by the following method. That is, β-ketoester or β-diketone is dropped into organooxytitanium such as alkoxytitanium, and the mixture is stirred at room temperature or in a heated state. Then, the alcohol is distilled off from the reaction solution to obtain organotitanium compound (I) having an organooxy group and a chelating ligand represented by the average composition formula (I). Next, a fatty acid ester of a polyhydric alcohol is dropped into the obtained organotitanium compound (I), and the mixture is stirred at room temperature or in a heated state. Then, the fatty acid ester is distilled off from the reaction solution to produce the desired organotitanium compound. The reaction amount ratio (molar ratio) of the organotitanium compound having an organoxy group and a chelating ligand represented by the average composition formula (I) to the fatty acid ester of a polyhydric alcohol, [organotitanium compound (I)]:[polyhydric alcohol fatty acid ester], is preferably 1:0.1 to 1:3.5, more preferably 1:0.3 to 1:2, and even more preferably 1:0.5 to 1:1.

[0020] A solvent may be used appropriately during the above reaction. Specific examples of usable solvents include hydrocarbon solvents such as pentane, hexane, cyclohexane, heptane, isooctane, benzene, toluene, and xylene; ether solvents such as diethyl ether, tetrahydrofuran, and dioxane; ester solvents such as ethyl acetate and butyl acetate; and chlorinated hydrocarbon solvents such as dichloromethane and chloroform. These solvents may be used alone or in combination of two or more.

[0021] The reaction temperature during the above reaction is not particularly limited, and the reaction can be carried out from room temperature (23°C±15°C) under heating, preferably from room temperature (23°C±15°C) to 200°C. In order to obtain an appropriate reaction rate, it is preferable to carry out the reaction under heating, and from this viewpoint, the reaction temperature is more preferably 40 to 110°C, and even more preferably 40 to 90°C. The reaction time is also not particularly limited, and is preferably 1 to 60 hours, more preferably 1 to 30 hours, and even more preferably 1 to 20 hours.

[0022] The organotitanium compound of the present invention is obtained by reacting an organotitanium compound (I) having an organoxy group and a chelating ligand with a fatty acid ester of a polyhydric alcohol, and conceptually, for example, has the average composition formula (II): Ti(OR) 4-a-b (Y) b (X) a (In the formula, R, X, and a are the same as above, Y is a polyhydric alcohol fatty acid ester residue present in the organic titanium compound of the present invention which is the final product, and b is the ratio of the polyhydric alcohol fatty acid ester residue present in the organic titanium compound of the present invention to the titanium atom, and is a number where 0 < b < 0.5), but regarding the molecular structure of the organic titanium compound of the present invention which is the final product, the average composition formula (I): Ti(OR) 4-a (X) a It is difficult to accurately specify what proportion of the total organooxy groups (OR) in the organic titanium compound (I) represented by is exchanged with the ester group and / or alkoxy group in the fatty acid ester of the polyhydric alcohol (that is, it is difficult to accurately grasp the value of b in the above formula (II)). Moreover, since there are multiple reaction sites of the polyhydric alcohol fatty acid ester in the molecule, the valence of the polyhydric alcohol fatty acid ester exchanged with the organooxy group (OR) in the organic titanium compound (I) (that is, at how many places in the molecule the polyhydric alcohol fatty acid ester is bonded to the Ti atom), and which site of the alkoxy group and / or ester group in the polyhydric alcohol fatty acid ester is involved in the exchange reaction (that is, the structure of Y in the above formula (II)) are also difficult to accurately specify. Therefore, it is impossible to represent by a general formula (structure) or directly specify by characteristics.

Examples

[0023] Hereinafter, examples and comparative examples will be shown to specifically explain the present invention, but the present invention is not limited thereto. Note that normal pressure means 1 atm, and room temperature in the examples means 25 ± 5°C. Also, the viscosity indicates the measured value by a rotational viscometer (Brookfield type viscometer) at 25°C.

[0024] [Example 1] Synthesis of Organic Titanium Compound 1 200g (0.70mol) of tetraisopropoxytitanium was charged into a 500ml separable flask, and 92g (0.70mol) of ethyl acetoacetate was added dropwise to it while stirring. After stirring for 2 hours at 50°C, the by-product isopropanol was distilled off to obtain a yellow liquid product with a representative average structure of titanium triisopropoxy (ethyl acetoacetate) (i.e., a compound corresponding to R = isopropyl group, X = ethyl acetoacetonato ligand, a = average 1.0 in the above average composition formula (I)). Next, 77g (0.35mol) of triacetin was added dropwise, and after stirring for 2 hours at 50°C, the by-product isopropyl acetate was distilled off to obtain the target organic titanium compound 1 (a reaction product of a compound corresponding to R = isopropyl group, X = ethyl acetoacetonato ligand, a = average 1.0 in the average composition formula (I) and triacetin in a molar ratio of 1:0.5).

[0025] [Example 2] Synthesis of organotitanium compound 2 An organic titanium compound 2 (a reaction product of a compound corresponding to the average composition formula (I) where R=isopropyl group, X=ethylacetoacetonato ligand, and a=average 1.0, and triacetin in a molar ratio of 1:1) was obtained in the same manner as in Example 1, except that 154 g (0.70 mol) of triacetin was used.

[0026] [Example 3] Synthesis of organotitanium compound 3 The same procedure as in Example 2 was repeated except that 123 g (0.70 mol) of diacetin was used instead of triacetin, to obtain organotitanium compound 3 (a reaction product of a compound corresponding to the average composition formula (I) where R=isopropyl group, X=ethylacetoacetonato ligand, and a=average 1.0, and diacetin in a molar ratio of 1:1).

[0027] [Example 4] Synthesis of organotitanium compound 4 The procedure of Example 2 was repeated except that 212 g (0.70 mol) of tributyrin was used instead of triacetin, and an organotitanium compound 4 (a reaction product of a compound represented by the average composition formula (I) in which R=isopropyl group, X=ethylacetoacetonato ligand, and a=average 1.0, and tributin in a molar ratio of 1:1) was obtained.

[0028] [Example 5] Synthesis of organotitanium compound 5 The same procedure as in Example 1 was repeated except that 70 g (0.70 mol) of acetylacetone was used instead of ethyl acetoacetate, to obtain organotitanium compound 5 (a reaction product of a compound represented by the average composition formula (I) in which R=isopropyl group, X=acetylacetonato ligand, and a=average 1.0, and triacetin in a molar ratio of 1:0.5).

[0029] [Comparative Example 1] Synthesis of organotitanium compound 6 An organic titanium compound 6 was obtained in the same manner as in Example 1, except that ethyl acetoacetate was not used.

[0030] [Comparative Example 2] Synthesis of organotitanium compound 7 An organic titanium compound 7 was obtained in the same manner as in Example 1, except that triacetin was not used.

[0031] Next, compositions were prepared using the organotitanium compounds synthesized in Examples 1 to 5 and Comparative Examples 1 and 2, and titanium diisopropoxybis(ethylacetoacetate) (product name TC-750: manufactured by Matsumoto Fine Chemical Co., Ltd.).

[0032] [Reference example 1] 100 parts of dimethylpolysiloxane having a viscosity of 50,000 mPa s and both molecular chain terminals blocked with hydroxyl groups, 50 parts of dimethylpolysiloxane having a viscosity of 100 mPa s and both molecular chain terminals blocked with trimethylsilyl groups, 100 parts of synthetic calcium carbonate "Hakuenka CCR (manufactured by Shiraishi Calcium Co., Ltd.)", and 100 parts of untreated calcium carbonate "Super S (manufactured by Maruo Calcium Co., Ltd.)" were uniformly mixed with the 100 parts of the dimethylpolysiloxane having both molecular chain terminals blocked with hydroxyl groups. Next, 9 parts of methyltrimethoxysilane and 4 parts of the organotitanium compound 1 synthesized in Example 1 were added to the 100 parts of the dimethylpolysiloxane having both molecular chain terminals blocked with hydroxyl groups, and the mixture was uniformly mixed under a moisture-proof condition to prepare a one-component dealcohol-free organopolysiloxane composition 1.

[0033] [Reference example 2] Composition 2 was prepared in the same manner as in Reference Example 1, except that organotitanium compound 2 synthesized in Example 2 was used instead of organotitanium compound 1.

[0034] [Reference example 3] Composition 3 was prepared in the same manner as in Reference Example 1, except that organotitanium compound 3 synthesized in Example 3 was used instead of organotitanium compound 1.

[0035] [Reference example 4] Composition 4 was prepared in the same manner as in Reference Example 1, except that organotitanium compound 4 synthesized in Example 4 was used instead of organotitanium compound 1.

[0036] [Reference example 5] Composition 5 was prepared in the same manner as in Reference Example 1, except that organotitanium compound 5 synthesized in Example 5 was used instead of organotitanium compound 1.

[0037] [Comparative Example 1] An attempt was made to prepare a composition in the same manner as in Reference Example 1, except that organotitanium compound 6 synthesized in Comparative Example 1 was used instead of organotitanium compound 1. However, a significant increase in viscosity was observed during the preparation, and composition 6 could not be obtained.

[0038] [Comparative Example 2] Composition 7 was prepared in the same manner as in Reference Example 1, except that organotitanium compound 7 synthesized in Comparative Example 2 was used instead of organotitanium compound 1.

[0039] [Comparative Example 3] Composition 8 was prepared in the same manner as in Reference Example 1, except that a commercially available organotitanium compound, titanium diisopropoxybis(ethylacetoacetate) (product name TC-750: manufactured by Matsumoto Fine Chemical Co., Ltd.), was added instead of organotitanium compound 1.

[0040] [Comparative Reference Example 4] Composition 9 was prepared in the same manner as in Comparative Reference Example 3, except that 1 part of triacetin was added.

[0041] Next, a physical property test, a storage stability test, and a hot water adhesion test were carried out on the compositions prepared in Reference Examples 1 to 5 and Comparative Reference Examples 1 to 4. The results of each test are shown in Table 1.

[0042] [Physical properties] The prepared composition was extruded into a polyethylene frame and cured at 23°C and 50% RH for 7 days to prepare a sheet having a thickness of 2 mm. The physical properties of this sheet were measured in accordance with JIS K 6249.

[0043] [Storage stability] The composition was placed in a polyethylene sealant cartridge (capacity 330 mL) and sealed with an inner stopper. The cartridge was stored in a dryer at 70°C for 7 days, then removed and the physical properties after heating and storage were measured in the same manner as above.

[0044] [Hot water adhesion test] The prepared composition was extruded onto float glass in the form of a bead, and cured at 23°C and 50% RH for 7 days to prepare a test specimen. The test specimen was immersed in 80°C hot water for 7 days, and after being removed, the bead was pulled in a 180° direction to confirm the adhesion. If the cured product underwent cohesive failure, it was recorded as ◯ for good adhesion, and if it peeled off, it was recorded as × for poor adhesion.

[0045] [Table 1]

[0046] From the results in Table 1, it is clear that the organotitanium compounds of the present invention produced in Examples 1 to 5 improve adhesion after immersion in hot water while maintaining catalytic activity and without impairing storage stability, compared to the organotitanium compounds produced in Comparative Examples 1 and 2 and existing organotitanium catalysts.

Claims

1. Average composition formula (I): Ti (OR) 4-a (X) a (wherein R is an alkyl group having 1 to 12 carbon atoms, X is a chelating ligand, and a is a number from 0.1 to 3.5). and a chelating ligand, with a fatty acid ester of a polyhydric alcohol, and distilling off the fatty acid ester produced as a by-product. the chelating ligand is a β-ketoester chelate or a β-diketone chelate; the fatty acid ester of a polyhydric alcohol is a fatty acid ester of ethylene glycol, propylene glycol, glycerol or pentaerythritol; The reaction product is an organotitanium compound in which at least a portion of the alkoxy groups (OR) in the organotitanium compound represented by the average composition formula (I) is replaced with a residue of a fatty acid ester of a polyhydric alcohol.

2. 2. The organic titanium compound according to claim 1, wherein the chelating ligand is ethyl acetoacetate chelate (ethylacetoacetonato) or acetylacetone chelate (acetylacetonato).

3. 3. The organic titanium compound according to claim 1, wherein the fatty acid ester of a polyhydric alcohol is at least one member selected from the group consisting of triacetin, diacetin and monoacetin.

4. The organotitanium compound according to any one of claims 1 to 3, which is a reaction product of an organotitanium compound (I) having an alkoxy group and a chelating ligand represented by average composition formula (I) and a fatty acid ester of a polyhydric alcohol in a molar ratio of [organotitanium compound (I)]:[polyhydric alcohol fatty acid ester]=1:0.1 to 1:3.

5.

5. A curing catalyst for a room-temperature curable resin composition, comprising an organotitanium compound represented by the average composition formula (I) according to any one of claims 1 to 4, which is a reaction product of an organotitanium compound and a fatty acid ester of a polyhydric alcohol.

6. Average composition formula (I): Ti (OR) 4-a (X) a (wherein R is an alkyl group having 1 to 12 carbon atoms, X is a chelating ligand, and a is a number from 0.1 to 3.5). a reaction step of dropping a fatty acid ester of a polyhydric alcohol to an organotitanium compound having an alkoxy group represented by the formula (I) and a chelating ligand, and stirring the reaction solution at room temperature or under heated conditions to obtain a reaction product; and A distillation step of distilling off a fatty acid ester produced as a by-product from the reaction liquid, the chelating ligand is a β-ketoester chelate or a β-diketone chelate; the fatty acid ester of a polyhydric alcohol is a fatty acid ester of ethylene glycol, propylene glycol, glycerol or pentaerythritol; A method for producing an organotitanium compound, in which the reaction product is an organotitanium compound represented by average composition formula (I) in which at least a portion of the alkoxy groups (OR) have been replaced with residues of fatty acid esters of polyhydric alcohols.

7. The method for producing an organic titanium compound according to claim 6, wherein the reaction temperature is 40 to 110°C.

Images