Process for producing polyoxypropylene polymer

Abstract

To provide a method for producing a polyoxypropylene polymer by which a high average molecular weight can be achieved in a relatively short polymerization time.SOLUTION: A method for producing a polyoxypropylene polymer having a number average molecular weight of 30000 or more and 70000 or less. The polymerization is carried out by adding propylene oxide with time to the reaction system containing the hydroxyl group-containing initiator and the double metal cyanide complex catalyst. The polymerization temperature is set to 120 to 160 °C, the water content in propylene oxide is 200ppm or less, and the ratio (X / Y) of the design molecular weight X to the time Y (min) required for the addition of propylene oxide is 95 to 130.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a polyoxypropylene polymer. [Background technology]

[0002] Polyoxypropylene polymers are widely used in applications such as sealants, adhesives, paints, etc. A known method for producing them is the ring-opening polymerization of propylene oxide in the presence of a hydroxyl group-containing initiator and a polymerization catalyst.

[0003] In this polymerization reaction, complex metal cyanide complex catalysts (also known as DMC catalysts) are often used as polymerization catalysts because they exhibit high activity, such as zinc hexacyanocobaltate complex.

[0004] For example, Patent Document 1 discloses that, for the purpose of producing a low-viscosity polyoxyalkylene polymer, a polymerization reaction of alkylene oxide is carried out in the presence of a composite metal cyanide complex catalyst while supplying the alkylene oxide at a predetermined rate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4277541 Summary of the Invention [Problem to be solved by the invention]

[0006] When an attempt is made to produce a polyoxypropylene polymer having a high average molecular weight, the reaction time required for the polymerization reaction tends to become longer. When the polymerization time is shortened in order to improve the productivity of the polymer, the average molecular weight or viscosity of the polymer decreases, making it difficult to obtain a polyoxypropylene-based polymer having the desired average molecular weight or viscosity.

[0007] In view of the above-mentioned current situation, an object of the present invention is to provide a method for producing a polyoxypropylene polymer, which can achieve a high average molecular weight in a relatively short polymerization time. [Means for solving the problem]

[0008] The present inventors have conducted studies and found that, when polymerizing propylene oxide in the presence of a hydroxyl group-containing initiator and a double metal cyanide complex catalyst, a polyoxypropylene polymer having a high average molecular weight can be produced in a relatively short polymerization reaction time by setting the temperature of the reaction system and the water content in the propylene oxide within respective predetermined ranges, and also by controlling the ratio of the designed molecular weight to the time required for adding propylene oxide within a predetermined range, thereby completing the present invention.

[0009] That is, the present invention provides a method for producing a polyoxypropylene-based polymer having a number average molecular weight of 30,000 or more and 70,000 or less as measured by gel permeation chromatography, comprising the steps of: The method includes a step of polymerizing propylene oxide by adding propylene oxide over time to a reaction system containing a hydroxyl group-containing initiator and a composite metal cyanide complex catalyst, The polymerization is carried out at a temperature set in the range of 120 to 160°C, The water content in the propylene oxide is 200 ppm or less, The ratio (X / Y) of the designed molecular weight X to the time Y (minutes) required for the addition of propylene oxide is 95 to 130. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a method for producing a polyoxypropylene polymer, which can achieve a high average molecular weight in a relatively short polymerization time. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail. The present embodiment relates to a method for producing a polyoxypropylene-based polymer, and includes a step of polymerizing propylene oxide by adding propylene oxide over time to a reaction system containing a hydroxyl group-containing initiator and a double metal cyanide complex catalyst.

[0012] The present embodiment aims to produce a high-molecular-weight polyoxypropylene polymer having a number-average molecular weight of 30,000 or more and 70,000 or less. To produce such a high-molecular-weight polyoxypropylene polymer, it is desirable to add propylene oxide, a monomer, to the reaction system continuously or intermittently over a period of time. According to the present embodiment, the time required for adding propylene oxide and carrying out the reaction can be shortened.

[0013] The number average molecular weight of the polyoxypropylene polymer produced is not particularly limited as long as it is within the range of 30,000 to 70,000. The upper limit is preferably 70,000 or less because the polymer is easy to handle, but may be 60,000 or less, 50,000 or less, or 40,000 or less. The number average molecular weight is a value measured by gel permeation chromatography (GPC) and calculated in terms of polystyrene.

[0014] The molecular weight distribution (Mw / Mn) of the produced polyoxypropylene polymer is not particularly limited, but is preferably narrow. Specifically, it is preferably less than 2.0, more preferably 1.6 or less, even more preferably 1.5 or less, and particularly preferably 1.4 or less. From the viewpoint of improving mechanical properties such as durability and elongation of the cured product, it is preferably 1.3 or less, and particularly preferably 1.2 or less. The molecular weight distribution (Mw / Mn) can be calculated from the number average molecular weight and weight average molecular weight determined in polystyrene equivalent terms by GPC measurement.

[0015] The viscosity of the polyoxypropylene polymer to be produced is not particularly limited, but the viscosity measured at 23° C. is preferably 40 Pa s or more, more preferably 50 Pa s or more, even more preferably 60 Pa s or more, particularly preferably 80 Pa s or more, and most preferably 90 Pa s or more. According to this embodiment, a polyoxypropylene polymer with such a high viscosity can be produced in a short time.

[0016] Propylene oxide used as a monomer is a highly water-absorbent substance and therefore usually contains water as an impurity. However, as the water content of propylene oxide increases, the average molecular weight of the resulting polyoxypropylene polymer tends to decrease. Therefore, in order to efficiently produce a high-molecular-weight polyoxypropylene polymer, it is preferable to use propylene oxide with a low water content. Specifically, the water content in propylene oxide is preferably 200 ppm or less, more preferably 150 ppm or less, even more preferably 130 ppm or less, and particularly preferably 100 ppm or less.

[0017] From the viewpoint of increasing the molecular weight of a polyoxypropylene-based polymer, it is preferable that the water content in propylene oxide is low. However, it is difficult to industrially utilize propylene oxide with an extremely low water content. From the viewpoint of ease of industrial use, the water content in propylene oxide is preferably 20 ppm or more, more preferably 40 ppm or more, and even more preferably 50 ppm or more. According to this embodiment, even when propylene oxide containing a certain amount of water is used, a high-molecular-weight polyoxypropylene-based polymer can be produced with good productivity.

[0018] As the propylene oxide having the water content as described above, commercially available products may be used as long as the water content is within the above range. Alternatively, propylene oxide having a reduced water content may be used by appropriately subjecting commercially available products containing a large amount of water to a known drying or dehydration procedure.

[0019] The hydroxyl group-containing initiator is not particularly limited, but examples thereof include monohydric alcohols such as methanol, ethanol, 1-propanol, 2-propanol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-2-butanol, and 2,2-dimethyl-1-propanol; ethylene glycol, propylene glycol, and butanediol. Examples of initiators include dihydric or polyhydric alcohols such as hexamethylene glycol, methallyl alcohol, hydrogenated bisphenol A, neopentyl glycol, polybutadiene diol, diethylene glycol, trioxyethylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, polyoxypropylene triol, polyoxypropylene tetraol, dioxypropylene glycol, glycerin, trimethylolmethane, trimethylolpropane, and pentaerythritol; and various polymers having hydroxyl groups. Only one of these may be used, or two or more may be used in combination. When various polymers having hydroxyl groups are used as initiators, polymers of the same type but with different molecular weights may be used in combination.

[0020] As the hydroxyl group-containing initiator, polyoxypropylene glycol and polyoxypropylene triol are preferably used. Among them, a compound having two hydroxyl groups in one molecule is more preferred, and polyoxypropylene glycol is preferably used, since it can produce a high molecular weight polyoxypropylene polymer.

[0021] The hydroxyl value of the hydroxyl-containing initiator is not particularly limited, but is usually preferably about 0.1 to 10 mmol / g, more preferably 3 mmol / g or less, and even more preferably 2 mmol / g or less.

[0022] When polyoxypropylene glycol or polyoxypropylene triol is used as the hydroxyl group-containing initiator, the molecular weight X' of the hydroxyl group-containing initiator is preferably about 500 to 20,000, more preferably 1,000 to 15,000, and even more preferably 1,500 to 12,000. The molecular weight X' of the hydroxyl group-containing initiator is defined by the following formula (2). Molecular weight X'=(n×1000) / a...(2) In formula (2), a is the hydroxyl value (mmol / g) of the hydroxyl group-containing initiator and is determined by the measurement method of JIS K 1557-1, and n is the number of hydroxyl groups contained in one molecule of the hydroxyl group-containing initiator.

[0023] In this embodiment, a composite metal cyanide complex catalyst is used as the polymerization catalyst, which makes it possible to obtain a polyoxypropylene polymer having a high molecular weight and a narrow molecular weight distribution (Mw / Mn).

[0024] The composite metal cyanide complex may be any known compound, and is not particularly limited. Among them, a composite metal cyanide complex having an organic ligand attached to a catalyst skeleton is preferred.

[0025] Examples of the catalyst skeleton of the composite metal cyanide complex include Zn3[Fe(CN)6]2, Zn3[Co(CN)6]2, Fe[Fe(CN)6], Fe[Co(CN)6], etc. In particular, the zinc hexacyanocobaltate complex represented by Zn3[Co(CN)6]2 is preferred.

[0026] Alcohols and ethers can be used as the organic ligand. Among these, alcohols such as tert-butyl alcohol, ethanol, sec-butyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-pentyl alcohol, isopentyl alcohol, and isopropyl alcohol; and ethers such as ethylene glycol dimethyl ether (glyme), diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), dioxane, and polyethers having a number-average molecular weight of 150 to 5,000 can be mentioned. Among these, ether-based organic solvents are preferred, and glyme is particularly preferred.

[0027] The amount of the composite metal cyanide complex used is not particularly limited, but is usually preferably 50 ppm by mass or more, more preferably 80 ppm by mass or more, and even more preferably 100 ppm by mass or more, relative to the polymer to be obtained, which allows the production of a polyoxypropylene-based polymer with a narrow molecular weight distribution (Mw / Mn).

[0028] The polymerization reaction of propylene oxide is preferably carried out in the presence of an organic solvent. The organic solvent is not particularly limited as long as it does not contain active hydrogen and is inactive in polymerization. Examples include aromatic compounds such as benzene, monochlorobenzene, toluene, ethylbenzene, styrene, o-, m-, and p-xylene, heterocyclic compounds such as tetrahydrofuran, dioxane, furan, and pyran, and polar compounds such as chain ethers such as butyl ethyl ether. The organic solvents may be used alone or in combination of two or more. Among them, heterocyclic compounds and chain ethers are preferred, with tetrahydrofuran, dioxane, and butyl ethyl ether being more preferred, and tetrahydrofuran being particularly preferred.

[0029] When polymerizing propylene oxide, first, a reaction system containing a hydroxyl group-containing initiator and a composite metal cyanide complex catalyst is prepared. The reaction system may contain a small amount of propylene oxide and the above-mentioned organic solvent. The reaction system containing the small amount of propylene oxide is preferably heated to a temperature of, for example, about 50 to 110°C to activate the composite metal cyanide complex catalyst.

[0030] Next, a high-molecular-weight polyoxypropylene polymer can be produced in a short polymerization time by carrying out a polymerization reaction at a temperature in the range of 120 to 160°C. The temperature may be, for example, 125 to 160°C, 125 to 150°C, 125 to 140°C, 130 to 160°C, 130 to 150°C, or 130 to 140°C.

[0031] While maintaining the temperature of the reaction system within this temperature range, polymerization is carried out while adding propylene oxide to the reaction system over time. The method of adding propylene oxide may be continuous or intermittent, as long as it is over time. It is desirable to add propylene oxide at a constant supply rate.

[0032] The time Y required for adding propylene oxide is set in relation to the designed molecular weight X as described below, and therefore its specific value is not particularly limited, but is usually preferably about 300 to 1000 minutes. The upper limit is more preferably 800 minutes or less, and even more preferably 600 minutes or less.

[0033] In this embodiment, a designed molecular weight X of the polyoxypropylene polymer is set. The designed molecular weight X is a theoretical value calculated from the hydroxyl value of the hydroxyl group-containing initiator used, the number of hydroxyl groups per molecule, the amount used, and the total amount of propylene oxide used, and differs from the number average molecular weight measured for an actually produced polymer or the target number average molecular weight. Specifically, the designed molecular weight X is determined by dividing the total weight of the initiator and propylene oxide by the number of moles of initiator per hydroxyl group, and can be calculated using the following formula (1): Design molecular weight X=(b+c) / (a×b / (n×1000))...(1)

[0034] In formula (1), a is the hydroxyl value (mmol / g) of the hydroxyl group-containing initiator and is determined by the measurement method of JIS K 1557-1. b is the weight (g) of the hydroxyl group-containing initiator, c is the total weight (g) of propylene oxide used in the polymerization, and n is the number of hydroxyl groups contained in one molecule of the hydroxyl group-containing initiator. The total weight of propylene oxide represented by c is the sum of the initial weight of propylene oxide contained in the initial reaction system and the weight of propylene oxide to be added.

[0035] When two or more initiators are used in combination, the designed molecular weight X is calculated by dividing the total weight of all initiators and propylene oxide by the total number of moles per hydroxyl group for each initiator. Specifically, when n initiators are used, the above formula (1) can be modified as follows: Design molecular weight In formula (1'), an is the hydroxyl value (mmol / g) of the nth hydroxyl-containing initiator, bn is the weight (g) of the nth hydroxyl-containing initiator, c is the total weight (g) of propylene oxide, and mn is the number of hydroxyl groups contained in one molecule of the nth hydroxyl-containing initiator.

[0036] As will be explained below, the designed molecular weight X is set in relation to the time Y required for adding propylene oxide, and therefore, its specific value is not particularly limited, but is usually preferably about 40,000 to 120,000, and more preferably about 50,000 to 100,000.

[0037] In this embodiment, the ratio (X / Y) of the designed molecular weight X to the time Y (minutes) required for the addition of propylene oxide is set in the range of 95 to 130. By setting the designed molecular weight according to the addition time within a predetermined range in this way, it becomes possible to produce a high-molecular-weight polyoxypropylene polymer in a short polymerization time. If X / Y is less than 95, the molecular weight of the polyoxypropylene polymer will not be sufficiently high. In this embodiment, the X / Y value may be, for example, 100 to 130, 100 to 125, 105 to 130, 105 to 125, 110 to 130, or 110 to 125.

[0038] The polymerization reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen or argon. After the addition of propylene oxide is completed, the polymerization reaction is continued for, for example, about 10 minutes to 1 hour, and then the unreacted propylene oxide and the organic solvent are distilled off to obtain a polyoxypropylene polymer. Furthermore, metal impurities derived from the polymerization catalyst can be removed by washing with water or an organic solvent.

[0039] According to the polymerization reaction described above, a polyoxypropylene polymer having a desired high number average molecular weight can be efficiently produced in a short polymerization time.

[0040] <Hydrolyzable Silyl Group-Containing Polyoxypropylene Polymer> The polyoxypropylene polymer obtained by this embodiment has a hydroxyl group at the end of the main chain. By utilizing this hydroxyl group, a hydrolyzable silyl group can be introduced via one or more steps, thereby producing a hydrolyzable silyl group-containing polyoxypropylene polymer.

[0041] The hydrolyzable silyl group is a silyl group that has a hydroxyl group or a hydrolyzable group bonded to a silicon atom and can form a crosslink by forming a siloxane bond. Specifically, it can be represented by the following formula: -SiR 1 b R 23-b (3) In the above formula, R 1 represents a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. 2 represents a hydroxyl group or a hydrolyzable group. b represents 0, 1 or 2, and is preferably 0 or 1.

[0042] R 1 The hydrocarbon group represented by the formula (R) preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms. 1 Specific examples of the group include a methyl group, an ethyl group, a chloromethyl group, a methoxymethyl group, an N,N-diethylaminomethyl group, etc. Preferred are a methyl group and an ethyl group.

[0043] R 2 Examples of the alkyl group include a hydroxyl group, hydrogen, halogen, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group, an alkenyloxy group, etc. Among these, alkoxy groups such as a methoxy group and an ethoxy group are more preferred because they are mildly hydrolyzable and easy to handle, and a methoxy group and an ethoxy group are particularly preferred.

[0044] Specific examples of the hydrolyzable silyl group include a trimethoxysilyl group, a triethoxysilyl group, a tris(2-propenyloxy)silyl group, a triacetoxysilyl group, a dimethoxymethylsilyl group, a diethoxymethylsilyl group, a dimethoxyethylsilyl group, a (chloromethyl)dimethoxysilyl group, a (chloromethyl)diethoxysilyl group, a (methoxymethyl)dimethoxysilyl group, a (methoxymethyl)diethoxysilyl group, an (N,N-diethylaminomethyl)dimethoxysilyl group, and an (N,N-diethylaminomethyl)diethoxysilyl group.

[0045] Although the specific method for producing the hydrolyzable silyl group-containing polyoxypropylene polymer is not particularly limited, an example thereof is a method in which the isocyanate group of a hydrolyzable silyl group-containing isocyanate compound is subjected to a urethane reaction with the hydroxyl group of the polyoxypropylene polymer. In the obtained hydrolyzable silyl group-containing polyoxypropylene polymer, the polymer backbone and the hydrolyzable silyl group are bonded via a urethane bond.

[0046] The hydrolyzable silyl group-containing isocyanate compound is not particularly limited as long as it is a compound having an isocyanate group and a hydrolyzable silyl group in the same molecule, and examples thereof include (isocyanatemethyl)trimethoxysilane, (isocyanatemethyl)triethoxysilane, (isocyanatemethyl)dimethoxymethylsilane, (isocyanatemethyl)diethoxymethylsilane, (3-isocyanatepropyl)trimethoxysilane, (3-isocyanatepropyl)dimethoxymethylsilane, (3-isocyanatepropyl)triethoxysilane, and (3-isocyanatepropyl)diethoxymethylsilane.

[0047] The urethanization reaction may be carried out without using a urethanization catalyst, or may be carried out in the presence of a urethanization catalyst for the purpose of improving the reaction rate or the reaction rate. Examples of such urethanization catalysts include conventionally known urethanization catalysts, such as those listed in "Polyurethanes: Chemistry and Technology," Part I, Table 30, Chapter 4, Saunders and Frisch, Interscience Publishers, New York, 1963. Specific examples include, but are not limited to, basic catalysts such as organotin compounds, bismuth compounds, and organic amines.

[0048] Another example of a method for producing a hydrolyzable silyl group-containing polyoxypropylene polymer is to react the hydroxyl groups of the polyoxypropylene polymer with an alkali metal salt, then with a carbon-carbon unsaturated bond-containing halide to convert them to carbon-carbon unsaturated bond-containing groups, and then subject the carbon-carbon unsaturated bond-containing groups to a hydrosilylation reaction with a hydrolyzable silyl group-containing hydrosilane compound to convert them to hydrolyzable silyl groups. The hydrolyzable silyl group-containing polyoxypropylene polymer obtained in this manner usually does not contain a urethane bond.

[0049] Specific examples of the alkali metal salt include, but are not limited to, sodium hydroxide, sodium alkoxide, potassium hydroxide, potassium alkoxide, lithium hydroxide, lithium alkoxide, cesium hydroxide, and cesium alkoxide.

[0050] Specific examples of the carbon-carbon unsaturated bond-containing halide include, but are not limited to, vinyl chloride, allyl chloride, methallyl chloride, vinyl bromide, allyl bromide, methallyl bromide, vinyl iodide, allyl iodide, methallyl iodide, etc. From the viewpoint of ease of handling, allyl chloride and methallyl chloride are preferred.

[0051] Alternatively, a polyoxypropylene-based polymer having two or more carbon-carbon unsaturated bonds at one end can be formed by first reacting the polyoxypropylene-based polymer after the reaction with the alkali metal salt with an epoxy compound having a carbon-carbon unsaturated bond (e.g., allyl glycidyl ether), and then reacting the resulting polymer with the above-mentioned carbon-carbon unsaturated bond-containing halide.

[0052] Specific examples of the hydrolyzable silyl group-containing hydrosilane compound include halosilanes such as trichlorosilane, dichloromethylsilane, chlorodimethylsilane, dichlorophenylsilane, (chloromethyl)dichlorosilane, (dichloromethyl)dichlorosilane, bis(chloromethyl)chlorosilane, (methoxymethyl)dichlorosilane, (dimethoxymethyl)dichlorosilane, and bis(methoxymethyl)chlorosilane; trimethoxysilane, triethoxysilane, dimethoxymethylsilane, and diethoxymethylsilane; Silane, dimethoxyphenylsilane, ethyldimethoxysilane, methoxydimethylsilane, ethoxydimethylsilane, (chloromethyl)methylmethoxysilane, (chloromethyl)dimethoxysilane, (chloromethyl)diethoxysilane, bis(chloromethyl)methoxysilane, (methoxymethyl)methylmethoxysilane, (methoxymethyl)dimethoxysilane, bis(methoxymethyl)methoxysilane, (methoxymethyl)diethoxysilane, (ethoxymethyl)diethoxysilane, (3,3,3-trifluoromethyl)silane (chloropropyl)dimethoxysilane, (N,N-diethylaminomethyl)dimethoxysilane, (N,N-diethylaminomethyl)diethoxysilane, [(chloromethyl)dimethoxysilyloxy]dimethylsilane, [(chloromethyl)diethoxysilyloxy]dimethylsilane, [(methoxymethyl)dimethoxysilyloxy]dimethylsilane, [(methoxymethyl)diethoxysilyloxy]dimethylsilane, [(diethylaminomethyl)dimethoxysilyloxy]dimethylsilane, [(3,3,3-trifluoromethyl)dimethoxysilyloxy]dimethylsilane Examples of the silanes include alkoxysilanes such as (chloropropyl)dimethoxysilyloxydimethylsilane; acyloxysilanes such as diacetoxymethylsilane and diacetoxyphenylsilane; ketoximate silanes such as bis(dimethylketoximate)methylsilane and bis(cyclohexylketoximate)methylsilane; and isopropenyloxysilanes (deacetone type) such as triisopropenyloxysilane, (chloromethyl)diisopropenyloxysilane, and (methoxymethyl)diisopropenyloxysilane.

[0053] The hydrosilylation reaction is preferably carried out in the presence of a hydrosilylation catalyst to promote the reaction. Examples of the hydrosilylation catalyst include metals such as cobalt, nickel, iridium, platinum, palladium, rhodium, and ruthenium, as well as complexes thereof. Specific examples include platinum supported on a support such as alumina, silica, or carbon black; chloroplatinic acid; chloroplatinic acid complexes composed of chloroplatinic acid and alcohols, aldehydes, or ketones; platinum-olefin complexes [e.g., Pt(CH2=CH2)2(PPh3), Pt(CH2=CH2)2Cl2]; platinum-vinylsiloxane complexes [e.g., Pt{(vinyl)Me2SiOSiMe2(vinyl)}, Pt{Me(vinyl)SiO}4]; platinum- Examples of suitable catalysts include phosphine complexes [e.g., Ph(PPh3)4, Pt(PBu3)4], platinum-phosphite complexes [e.g., Pt{P(OPh)3}4], and ruthenium complexes in which ruthenium is coordinated with 2,3-dibromonorbornadiene, 1,4-dibromobenzene, 1-bromo-3,5-difluorobenzene, 1-bromo-2,6-difluorobenzene, 1,3,5-tribromobenzene, 1,4-diiodobenzene, or hexabromobenzene. Platinum catalysts such as chloroplatinic acid and platinum vinylsiloxane complexes are preferred in terms of reaction efficiency, and ruthenium complexes are preferred in terms of improving the silyl group introduction rate.

[0054] <Curable composition containing hydrolyzable silyl group-containing polyoxypropylene polymer> The hydrolyzable silyl group-containing polyoxypropylene polymer produced as described above can be used as a curable composition containing the same. The curable composition may contain only one type of polyoxypropylene polymer, or two or more types of polyoxypropylene polymers in combination.

[0055] To the curable composition containing the hydrolyzable silyl group-containing polyoxypropylene polymer, a curing catalyst, a silicon compound, an adhesion promoter, a plasticizer, a solvent, a diluent, a silicate, a filler, an anti-sagging agent, an antioxidant, a light stabilizer, an ultraviolet absorber, a physical property adjuster, a tackifying resin, a compound containing an epoxy group, a photocurable substance, an oxygen-curable substance, a surface property improver, an epoxy resin, other resins, a flame retardant, a foaming agent, etc. may be added.

[0056] Furthermore, various additives may be added to the curable composition as needed for the purpose of adjusting the physical properties of the composition or the cured product, such as a curability adjuster, a radical inhibitor, a metal deactivator, an antiozonant, a phosphorus-based peroxide decomposer, a lubricant, a pigment, and a mildew inhibitor.

[0057] <<Application>> The curable composition can be used as a pressure-sensitive adhesive, a sealing material for buildings, ships, automobiles, roads, etc., an adhesive, a waterproofing material, a waterproof coating material, a mold release agent, an anti-vibration material, a vibration-damping material, a sound-proofing material, a foam material, a paint, or a spray material. The cured product obtained by curing the curable composition has excellent flexibility and adhesiveness, and can therefore be suitably used as a sealant or adhesive.

[0058] The curable composition can also be used in a wide range of applications, including electrical and electronic component materials such as solar cell backside sealing materials, electrical and electronic components such as insulating coating materials for electric wires and cables, electrical insulating materials for devices, acoustic insulating materials, elastic adhesives, binders, contact adhesives, spray-type sealants, crack repair materials, tiling adhesives, adhesives for asphalt waterproofing materials, powder coatings, casting materials, medical rubber materials, medical pressure-sensitive adhesives, medical adhesive sheets, medical device sealants, dental impression materials, food packaging materials, joint sealants for exterior materials such as sizing boards, These compounds can be used in a wide variety of applications, including coatings, anti-slip coatings, buffer materials, primers, conductive materials for electromagnetic wave shielding, thermally conductive materials, hot melt materials, potting agents for electrical and electronic applications, films, gaskets, concrete reinforcement materials, temporary adhesives, various molding materials, and as anti-rust and waterproof sealants for wired glass and laminated glass edge (cut sections), as well as liquid sealants used in automobile parts, large vehicle parts such as trucks and buses, train parts, aircraft parts, marine parts, electrical components, and various machine parts. For example, in automobiles, they can be used for a wide variety of applications, including adhesive attachment of plastic covers, trim, flanges, bumpers, window mounting, interior components, and exterior components. Furthermore, because they can adhere to a wide range of substrates, such as glass, porcelain, wood, metal, and resin moldings, either alone or with the aid of a primer, they can also be used as various types of sealing and adhesive compositions. The composition according to the present embodiment can also be used as an adhesive for interior panels, exterior panels, tile adhesives, stone veneers, ceiling finishes, floor finishes, wall finishes, vehicle panels, electrical, electronic, and precision equipment assembly adhesives, adhesives for bonding leather, textiles, fabrics, paper, boards, and rubber, reactive post-crosslinked pressure-sensitive adhesives, direct glazing sealants, double-glazing sealants, SSG construction sealants, building working joint sealants, civil engineering and bridge materials, and adhesive materials such as adhesive tapes and sheets.

[0059] The following items list preferred aspects of the present disclosure, but the present invention is not limited to the following items. [Item 1] A method for producing a polyoxypropylene polymer having a number average molecular weight of 30,000 or more and 70,000 or less as measured by gel permeation chromatography, comprising: The method includes a step of polymerizing propylene oxide by adding propylene oxide over time to a reaction system containing a hydroxyl group-containing initiator and a composite metal cyanide complex catalyst, The polymerization is carried out at a temperature set in the range of 120 to 160°C, The water content in the propylene oxide is 200 ppm or less, The method, wherein the ratio (X / Y) of the designed molecular weight X to the time Y (minutes) required for the addition of propylene oxide is 95 to 130. [Item 2] Item 2. The production method according to Item 1, wherein the water content in the propylene oxide is 40 ppm or more. [Item 3] 3. The method according to item 1 or 2, wherein the hydroxyl group-containing initiator has two hydroxyl groups in one molecule. [Item 4] 4. The method according to any one of items 1 to 3, wherein the double metal cyanide complex catalyst is a double metal cyanide complex catalyst containing an ether-based organic solvent as a ligand. [Item 5] 5. The method according to any one of items 1 to 4, wherein the polyoxypropylene polymer has a viscosity of 40 Pa·s or more at 23° C. [Example]

[0060] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0061] (number average molecular weight, weight average molecular weight) The number average molecular weight (Mn) and weight average molecular weight (Mw) of the polymer are GPC molecular weights measured under the following conditions. Liquid delivery system: Tosoh HLC-8420GPC Column: Tosoh TSK-GEL H type Solvent: THF (tetrahydrofuran) Molecular weight: Polystyrene equivalent Measurement temperature: 40℃

[0062] (PO water content) The water content in propylene oxide (PO water content) is a value measured using a Karl Fischer moisture meter (model MKH-700) manufactured by Kyoto Electronics Manufacturing Co., Ltd.

[0063] Example 1 0.50 g of zinc hexacyanocobaltate glyme complex catalyst as a composite metal cyanide complex catalyst, 90 g of tetrahydrofuran (THF), 360 g of polyoxypropylene glycol (hydroxyl value 0.179 mmol / g) having two hydroxyl groups per molecule as initiators, 166 g of polyoxypropylene glycol (hydroxyl value 0.676 mmol / g) having two hydroxyl groups per molecule as initiators, and 60 g of propylene oxide (PO) were charged into a reaction vessel and heated to 95°C while stirring with a stirrer to activate the catalyst. Next, 3741 g of propylene oxide, the moisture content of which had been measured in advance, was added over 480 minutes while maintaining the internal temperature of the reaction vessel at 135° C. The moisture content of the additional propylene oxide used was 60 ppm. After the polymerization reaction was completed, the polymerization reaction was continued for another 30 minutes, and then unreacted PO and THF were removed to obtain a polyoxypropylene polymer. Table 1 shows the number average molecular weight and weight average molecular weight of the resulting polymer measured by gel permeation chromatography, and the molecular weight distribution calculated from the number average molecular weight and weight average molecular weight. In addition, 0.5 mL of the obtained polymer was sampled, and the viscosity was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., product name: RE-85U type) at a measurement temperature of 23°C with rotor No. 4 (3° x R14). JS14000 (manufactured by Nippon Grease Co., Ltd.) was used as the calibration standard solution. The viscosity values ​​of the obtained polymer are shown in Table 1.

[0064] (Examples 2 and 3, Comparative Examples 1 and 2, Reference Example 1) A polyoxypropylene polymer was obtained in the same manner as in Example 1, except that the conditions were changed to those shown in Table 1. In the same manner as in Example 1, the number average molecular weight, weight average molecular weight, molecular weight distribution and viscosity of the obtained polymer were measured and are shown in Table 1.

[0065] [Table 1]

[0066] The following can be seen from Table 1: In Reference Example 1, propylene oxide was added and polymerization was carried out over a long period of time, 1080 minutes, to produce a polyoxypropylene polymer having the desired average molecular weight or viscosity.

[0067] In Comparative Example 1, the time Y required for adding propylene oxide was reduced to less than half that of Reference Example 1, but the number average molecular weight and viscosity of the produced polymer were significantly reduced. In Comparative Example 2, the designed molecular weight X was set to a value higher than in Comparative Example 1, and the PO water content was set to a slightly higher value, but the number average molecular weight and viscosity of the polymer did not increase.

[0068] In comparison with these comparative examples, in Examples 1 to 3 in which the design molecular weight X was set to a larger value, X / Y was controlled within a predetermined range, and the reaction temperature and the water content of PO were set within their respective predetermined ranges, the number average molecular weight and viscosity values ​​of the polymer were improved, and values ​​close to those of Reference Example 1 were achieved. That is, it can be seen that in Examples 1 to 3, polyoxypropylene-based polymers having number average molecular weights and viscosity values ​​comparable to those of Reference Example 1 could be produced in a reaction time significantly shorter than that of Reference Example 1.

Claims

1. A method for producing a polyoxypropylene polymer having a number average molecular weight of 30,000 or more and 70,000 or less as measured by gel permeation chromatography, comprising: The method includes a step of polymerizing propylene oxide by adding propylene oxide over time to a reaction system containing a hydroxyl group-containing initiator and a composite metal cyanide complex catalyst, The polymerization is carried out at a temperature set in the range of 120 to 160°C, The water content in the propylene oxide is 200 ppm or less, The method, wherein the ratio (X / Y) of the design molecular weight X to the time Y (minutes) required for the addition of propylene oxide is 95 to 130.

2. 2. The method according to claim 1, wherein the water content in the propylene oxide is 40 ppm or more.

3. The method according to claim 1 or 2, wherein the hydroxyl group-containing initiator has two hydroxyl groups in one molecule.

4. 3. The method according to claim 1, wherein the double metal cyanide complex catalyst contains an ether-based organic solvent as a ligand.

5. The method according to claim 1 or 2, wherein the polyoxypropylene polymer has a viscosity of 40 Pa·s or more at 23° C.

Images