Polyol composition for polyurethane resins and polyurethane resins

Abstract

This invention provides a polyol composition for polyurethane resins that can produce a polyurethane resin exhibiting excellent resin strength and weather resistance, as well as excellent handling properties for the urethane prepolymer precursor. [Solution] A polyol composition for polyurethane resins containing a divalent polyether polyol (A), which is a copolymer having segments of oxyalkylene groups having 2 to 3 carbon atoms at both ends of a segment of oxytetramethylene groups, wherein the average degree of polymerization (m) of the oxyalkylene groups having 2 to 3 carbon atoms is 9.0 to 24.0, and the ratio (n:m) of the average degree of polymerization (n) of the oxytetramethylene groups in the copolymer to the average degree of polymerization (m) of the oxyalkylene groups having 2 to 3 carbon atoms is 25:75 to 70:30.

Description

Technical Field

[0001] The present invention relates to a polyol composition for polyurethane resins and polyurethane resins.

Background Art

[0002] Conventionally, as moisture-permeable materials used for moisture-permeable waterproof fabrics, sheets obtained by stretching polytetrafluoroethylene resin to make them porous, microporous sheets such as wet film-forming films of polyurethane resins, etc. are known. However, conventional porous sheets have a problem that they are clogged with sweat, dirt, etc., and the moisture permeability decreases. As a solution to such problems, a non-porous polyurethane resin sheet coated with a hydrophilic moisture-permeable polyurethane resin has been proposed. This moisture-permeable polyurethane resin sheet contains a hydrophilic segment of polyoxyethylene in the polyurethane resin. Further, as a method of imparting hydrophilicity to a polyurethane resin, it is well known to use polyoxyethylene glycol, a block copolymer of polyoxyethylene and polyoxypropylene, etc. in the polyol component (Patent Documents 1 to 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the non-porous polyurethane resin containing the above hydrophilic segment cannot be said to have sufficient weather resistance, and the handling property of the urethane prepolymer as a precursor is not sufficient, leaving room for improvement. The present invention aims to solve the above problems and provide a polyol composition for polyurethane resins that can produce a polyurethane resin exhibiting excellent resin strength and weather resistance, and with excellent handling properties for the urethane prepolymer precursor. Furthermore, the present invention aims to provide a polyurethane resin that can be obtained using the polyol composition for polyurethane resins. [Means for solving the problem]

[0005] The inventors of this invention arrived at this present invention after diligent research. The present invention relates to a polyol composition for polyurethane resins containing a divalent polyether polyol (A) which is a copolymer having segments of oxytetramethylene groups at both ends and segments of oxyalkylene groups having 2 to 3 carbon atoms, wherein the average degree of polymerization (m) of the oxyalkylene groups having 2 to 3 carbon atoms is 9.0 to 24.0, and the ratio (n:m) of the average degree of polymerization (n) of the oxytetramethylene groups in the copolymer to the average degree of polymerization (m) of the oxyalkylene groups having 2 to 3 carbon atoms is 25:75 to 70:30. Furthermore, the present invention relates to a polyurethane resin obtained by reacting the polyol component and the polyisocyanate component of the polyol composition for polyurethane resins. [Effects of the Invention]

[0006] By using the polyol composition for polyurethane resins of the present invention, it is possible to obtain a polyurethane resin that exhibits excellent handling properties of the urethane prepolymer precursor, as well as excellent resin strength and weather resistance. [Modes for carrying out the invention]

[0007] The present invention will be described in detail below. The polyol composition for polyurethane resins of the present invention is a polyol composition containing at least a divalent polyether polyol (A). Furthermore, the polyurethane resin of the present invention is obtained by reacting the polyol component and the polyisocyanate component of the polyol composition for polyurethane resins.

[0008] The polyol composition for polyurethane resins of the present invention contains a divalent polyether polyol (A) which is a copolymer having segments of oxyalkylene groups having 2 to 3 carbon atoms at both ends of a segment of oxytetramethylene groups, the average degree of polymerization (m) of the 2 to 3 carbon atom oxyalkylene groups being 9.0 to 24.0, and the ratio (n:m) of the average degree of polymerization (n) of the oxytetramethylene groups to the average degree of polymerization (m) of the 2 to 3 carbon atom oxyalkylene groups in the copolymer being 25:75 to 70:30.

[0009] The divalent polyether polyol (A) is a copolymer having segments consisting of oxytetramethylene groups and segments consisting of oxyalkylene groups having 2 to 3 carbon atoms. In the copolymer, m is the average degree of polymerization of the oxyalkylene groups, and m is a number from 9.0 to 24.0, preferably from 9.0 to 21.0. If m is less than 9.0, the proportion of segments consisting of oxyalkylene groups having 2 to 3 carbon atoms becomes relatively small, and the amount of hydrophilic segments in the resulting polyurethane resin tends to be insufficient, making it difficult to achieve both weather resistance and resin strength. On the other hand, if m exceeds 24.0, the proportion of segments consisting of oxyalkylene groups having 2 to 3 carbon atoms becomes relatively large, and the viscosity of the resulting urethane prepolymer tends to decrease excessively, or its stability at high temperatures tends to be impaired, potentially reducing handling properties and weather resistance.

[0010] Furthermore, in the copolymer, n is the average degree of polymerization of the oxytetramethylene groups, and from the viewpoint of handling properties of the urethane prepolymer and weather resistance and resin strength of the resulting polyurethane resin, it is preferably a number from 4.0 to 30.0, more preferably a number from 9.0 to 21.0, and even more preferably a number from 8.5 to 18.0.

[0011] Furthermore, the average degree of polymerization (n) of the oxytetramethylene group and the average degree of polymerization (m) of the oxyalkylene group in the copolymer are: 1 It is calculated from the methylene group of the oxytetramethylene group and the internal methylene group of the oxyalkylene group, which are quantified by 1H-NMR. Furthermore, when a carbon-2 to carbon-3 oxyalkylene group includes both a carbon-2 oxyalkylene group (oxyethylene group) and a carbon-3 oxyalkylene group (oxypropylene group), the average degree of polymerization (m) of the oxyalkylene group is defined as the sum of the average degree of polymerization of the oxyethylene group (mEO) and the average degree of polymerization of the oxypropylene group (mPO) (m = mEO + mPO). In this case, mEO and mPO are, 1 This is calculated using the proton signal derived from the oxyalkylene group, which is quantified by 1H-NMR.

[0012] Furthermore, in the copolymer, the ratio (n:m) of the average degree of polymerization of the oxytetramethylene groups (n) to the average degree of polymerization of the oxyalkylene groups (m) in the copolymer is 25:75 to 70:30. If the n:m ratio is less than 25:75, the proportion of oxytetramethylene groups becomes relatively low, and the amount of hydrophobic segments in the resulting polyurethane resin tends to be insufficient. As a result, there is a risk of deterioration in appearance (e.g., cracking) and a decrease in tensile strength after weathering tests. Furthermore, if the n:m ratio is greater than 70:30, the proportion of oxytetramethylene groups becomes relatively high, which can easily lead to an excessive increase in the viscosity of the urethane prepolymer and a decrease in handling properties. In addition, the amount of segments consisting of oxyalkylene groups with 2 to 3 carbon atoms may be insufficient, making it difficult to achieve both weather resistance and resin strength.

[0013] Examples of the divalent polyether polyol (A) include ethylene oxide (EO) and / or propylene oxide (PO) adducts of polytetramethylene glycol. EO and PO may be used individually or in combination, and in the case of combination polymerization, either random addition polymerization or block polymerization may be carried out.

[0014] Examples of commercially available polytetramethylene glycols include PTMG650 [poly(oxytetramethylene) glycol with a number-average molecular weight (hereinafter also referred to as "Mn") = 650, manufactured by Mitsubishi Chemical Corporation], PTMG850 [poly(oxytetramethylene) glycol with Mn = 850, manufactured by Mitsubishi Chemical Corporation], PTMG1000 [poly(oxytetramethylene) glycol with Mn = 1,000, manufactured by Mitsubishi Chemical Corporation], and PTMG1300. Examples include [poly(oxytetramethylene) glycol with Mn=1,300, manufactured by Mitsubishi Chemical Corporation], PTMG1500 [poly(oxytetramethylene) glycol with Mn=1,500, manufactured by Mitsubishi Chemical Corporation], PTMG2000 [poly(oxytetramethylene) glycol with Mn=2,000, manufactured by Mitsubishi Chemical Corporation], and PTMG3000 [poly(oxytetramethylene) glycol with Mn=3,000, manufactured by Mitsubishi Chemical Corporation].

[0015] The polyol component may include polyol components other than the divalent polyether polyol (A). Examples of polyol components other than the divalent polyether polyol (A) include low molecular weight polyhydric alcohols (including those that can function as chain extenders or crosslinking agents), polyether polyols other than the divalent polyether polyol (A), polyester polyols, polycarbonate polyols, polycaprolactone polyols, polybutadiene polyols, naturally derived polyols such as castor oil, and modified polyols thereof. These may be used individually or in combination of two or more.

[0016] Examples of the low molecular weight polyhydric alcohol include, as a dihydric polyol, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, etc. Further, examples of the trihydric polyol include glycerin, trimethylolpropane, triethanolamine, and as the sugar alcohol, sorbitol, etc. These low molecular weight polyhydric alcohols can be used as a chain extender or a crosslinking agent for the polyurethane resin.

[0017] Examples of the polyether polyol other than the dihydric polyether polyol (A) include polyoxypropylene glycol, polyoxyethylene glycol, polyoxypropylene-polyoxyethylene block copolymer, and polymer polyol obtained by polymerizing styrene, acrylonitrile, etc. with these.

[0018] Examples of the polyester polyol include polyester polyol obtained by condensing a polyvalent carboxylic acid component such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, or their anhydrides, etc. with a polyhydric alcohol component such as ethylene glycol, 1,4-butanediol, neopentyl glycol, diethylene glycol, etc.

[0019] Examples of the polycarbonate polyol include polycarbonate diol obtained by reacting a carbonate compound such as diphenyl carbonate with a polyhydric alcohol such as 1,6-hexanediol, 1,4-butanediol, cyclohexanedimethanol, etc.

[0020] The number average molecular weight, hydroxyl value, functional group number, etc. of the polyol component other than the dihydric polyether polyol (A) may be appropriately set according to the physical properties of the desired polyurethane resin (for example, strength, elongation, weather resistance, hydrolysis resistance, moisture permeability, and handling property).

[0021] The content of the divalent polyether polyol (A) in the polyol component may be appropriately set according to desired physical properties. For example, based on the total weight of the polyol component, it is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, and still more preferably 30 to 70% by weight.

[0022] As the polyol component other than the divalent polyether polyol (A), commercially available products may be used. For example, as the polyether polyol, Sunnex GP-1500 (manufactured by Sanyo Chemical Industries, Ltd.) etc. may be used.

[0023] The divalent polyether polyol (A) is a copolymer obtained by polymerizing polytetramethylene glycol as a starting material with EO and / or PO in the presence of a catalyst. Examples of the catalyst include acid catalysts, alkali catalysts, double cyanide complex (DMC) catalysts, etc.

[0024] As the acid catalyst, for example, Lewis acids, solid acids, superacids, etc. can be used.

[0025] Examples of Lewis acids include halides or alkyl compounds of boron, aluminum, tin, antimony, iron, phosphorus, zinc, titanium, zirconium, and beryllium. Specifically, these include boron halides such as boron trifluoride and boron trichloride; alkyl compounds of boron such as triphenylboron, tri(t-butyl)boron, tris(pentafluorophenyl)boron, bis(pentafluorophenyl)-t-butylboron, bis(pentafluorophenyl)boron fluoride, di(t-butyl)boron fluoride, and (pentafluorophenyl)difluoroboron; aluminum halides such as aluminum chloride and aluminum bromide; triethylaluminum, triphenylaluminum, diphenyl-t-butylaluminum, tri Examples include alkyl compounds of aluminum such as s(pentafluorophenyl)aluminum, bis(pentafluorophenyl)-t-butylaluminum, bis(pentafluorophenyl)aluminum fluoride, di(t-butyl)aluminum fluoride, (pentafluorophenyl)difluoride and (t-butyl)difluoride; tin halides such as tin tetrafluoride and tin tetrachloride; and antimony fluoride, antimony chloride, ferric chloride, phosphorus pentafluoride, zinc chloride, diethylzinc, titanium tetrachloride, zirconium chloride, and beryllium chloride. The Lewis acids mentioned above may be used alone, but complexes with various organic compounds are also known, and the following complexes may be used. Examples of such complexes include ether complexes such as dimethyl ether complexes, diethyl ether complexes, and THF complexes; carboxylic acid complexes such as acetic acid complexes; alcohol complexes; amine complexes; and phenol complexes. Of these complexes, boron trifluoride ether complexes and boron trifluoride tetrahydrofuran complexes are preferred, and boron trifluoride tetrahydrofuran complexes are even more preferred.

[0026] Examples of solid acids include clay minerals (e.g., kaolinite and montmorillonite), zeolites, cation exchange resins, metal oxides (e.g., zinc oxide and aluminum oxide), and heteropoly acids.

[0027] Examples of superacids include trifluoromethanesulfonic acid and fluorosulfonic acid.

[0028] Of the above acid catalysts, Lewis acids are preferred, boron trifluoride ether complexes and boron trifluoride tetrahydrofuran complexes are more preferred, and boron trifluoride tetrahydrofuran complexes are particularly preferred.

[0029] As an alkaline catalyst, for example, alkali metal hydroxide catalysts (lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.) can be used. Of the above alkaline catalysts, potassium hydroxide is preferred.

[0030] As DMC catalysts, Zn3[Fe(CN)6]2, Zn3[Co(CN)6]2, Fe[Fe(CN)6], and Fe[Co(CN)6] can be used.

[0031] As a DMC catalyst, a catalyst having a structure in which organic ligands are coordinated to a catalytic skeleton of Zn3[Co(CN)6]2 (i.e., a zinc hexacyanocobaltate complex) is more preferred.

[0032] Examples of organic ligands include tert-butyl alcohol (hereinafter sometimes referred to as "TBA"), n-butyl alcohol, iso-butyl alcohol, tert-pentyl alcohol, iso-pentyl alcohol, N,N-dimethylacetamide, ethylene glycol mono-tert-butyl ether, ethylene glycol dimethyl ether (also called glyme), diethylene glycol dimethyl ether (also called diglyme), triethylene glycol dimethyl ether (also called triglyme), iso-propyl alcohol, and dioxane. Dioxane may be 1,4-dioxane or 1,3-dioxane, but 1,4-dioxane is preferred. One organic ligand may be used, or two or more may be used in combination. Among these, catalysts having TBA as an organic ligand are preferred because they yield polyether polyols with a narrower molecular weight distribution and lower viscosity, and the reaction proceeds more rapidly.

[0033] The hydroxyl value of the polyether polyol of the present invention is preferably 20 to 120 mg KOH / g, and more preferably 50 to 90 mg KOH / g, from the viewpoint of the handling properties of the urethane prepolymer obtained from the polyether polyol. The hydroxyl value used herein is measured by the method specified in JIS K 0070:1995.

[0034] <Method for producing divalent polyether polyol (A)> The divalent polyether polyol (A) used in the present invention is a copolymer having a segment consisting of oxytetramethylene groups and a segment consisting of oxyalkylene groups having 2 to 3 carbon atoms. For example, it can be obtained by using poly(oxytetramethylene) glycol (hereinafter also referred to as "PTMG") as an initiator and adding ethylene oxide (hereinafter also referred to as "EO") and / or propylene oxide (hereinafter also referred to as "PO").

[0035] As the initiator, PTMG with a number-average molecular weight of, for example, 500 to 3,000 can be used, preferably 650 to 2,000. The moisture content of the initiator is preferably low from the viewpoint of suppressing side reactions, and it may be dehydrated under reduced pressure before the reaction.

[0036] As catalysts used in addition polymerization, alkaline catalysts, complex cyanide complex (DMC) catalysts, etc., can be used. Examples of alkaline catalysts include potassium hydroxide. Examples of DMC catalysts include catalysts in which organic ligands are coordinated to a zinc hexacyanocobaltate complex as a catalytic skeleton. The amount of catalyst can be appropriately set depending on the type of raw material, the target molecular weight, etc., but for example, the amount of alkaline catalyst can be preferably 0.01 to 1.0% by weight relative to the initiator, and the amount of DMC catalyst can be preferably 0.0001 to 0.1% by weight relative to the initiator.

[0037] Addition polymerization can be carried out, for example, by charging an initiator and catalyst into a pressure reactor equipped with a stirrer, purging with nitrogen, dehydrating under reduced pressure, raising the temperature to a predetermined level, and then continuously or intermittently supplying EO and / or PO. The reaction temperature is, for example, 80 to 150°C, preferably 100 to 140°C, and the reaction pressure can be appropriately set according to the vapor pressure of the supplied oxides. A maturation step may be provided after the oxide supply is completed.

[0038] The reaction product can be purified and the catalyst removed as needed. For example, when an alkaline catalyst is used, the catalyst component can be reduced by treatment with an adsorbent such as silicate and water, followed by filtration and dehydration. When a DMC catalyst is used, catalyst-derived solids may be removed by filtration. The hydroxyl value of the resulting divalent polyether polyol (A) can be adjusted according to the physical properties and handling requirements of the desired polyurethane resin, for example, to 20-120 mg KOH / g.

[0039] <Polyisocyanate component> The polyurethane resin of the present invention can be obtained using a polyisocyanate component reacted with a polyol component. As the polyisocyanate component, aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, and modified versions thereof can be used.

[0040] Examples of aromatic polyisocyanates include tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate. Examples of aliphatic polyisocyanates include hexamethylene diisocyanate. Examples of alicyclic polyisocyanates include isophorone diisocyanate and 4,4'-dicyclohexylmethane diisocyanate. These may be used individually or in combination of two or more. From the viewpoint of weather resistance, it is preferable to use alicyclic polyisocyanates, and more preferable to use isophorone diisocyanate.

[0041] In addition to the diisocyanate mentioned above, modified polyisocyanates such as isocyanurate, biuret, allophanate, and uretdione compounds may be used as polyisocyanate components, if necessary.

[0042] <Polyurethane resin> The polyurethane resin of the present invention is obtained by reacting a polyol component containing the divalent polyether polyol (A) with a polyisocyanate component. The resulting polyurethane resin may be, for example, a crosslinked or chain-extended product obtained via a urethane prepolymer, and can be used in the form of a film, sheet, coating layer, adhesive layer, etc.

[0043] The polyurethane resin of the present invention exhibits excellent handling properties (e.g., viscosity) of the urethane prepolymer precursor, and can also show good properties in terms of weather resistance and resin strength.

[0044] <Method for manufacturing polyurethane resin> The polyurethane resin of the present invention can be produced, for example, by a method comprising (1) a urethane prepolymer manufacturing step and (2) a chain extension step.

[0045] (1) Manufacturing process of urethane prepolymer A urethane prepolymer can be obtained by mixing a polyol component and a polyisocyanate component in such a way that there is an excess of NCO groups, and reacting them under heating and stirring. At this time, the equivalent ratio of NCO groups to OH groups (NCO / OH) is preferably 1.2 to 4.0, and more preferably 1.5 to 3.5. The reaction temperature is, for example, 60 to 120°C, preferably 80 to 110°C, and the reaction time can be, for example, 1 to 10 hours. If necessary, a urethane reaction catalyst may be used. Examples of urethane reaction catalysts include organotin compounds and amine catalysts.

[0046] The NCO concentration of the urethane prepolymer can be set according to the desired curability and handling properties, but for example, it can be set to 4.0-6.0%. The viscosity of the urethane prepolymer is preferably adjusted to an appropriate range from the viewpoint of coating properties and mixing operability.

[0047] In addition to the divalent polyether polyol (A), other polyols (e.g., polyether polyols, polyester polyols, etc.) may be used in combination as needed.

[0048] (2) Chain extension process and molding process A polyurethane resin can be obtained by reacting the resulting urethane prepolymer with a chain extender. Examples of chain extenders include low molecular weight diols such as 1,4-butanediol and diamines, with 1,4-butanediol being preferred. The amount of chain extender can be set according to the desired physical properties. The low molecular weight polyhydric alcohol may be incorporated as part of the polyol component, or may be incorporated separately as a chain extender or crosslinking agent in the chain extension process.

[0049] The resin after chain extension can be molded, for example, into a sheet or film, and then heat-cured as needed to obtain a polyurethane resin film. Molding methods can include casting, extrusion, and coating, and heat-curing conditions can range from several hours to several days, for example, at room temperature to 120°C. [Examples]

[0050] The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited thereto.

[0051] <Manufacturing Example 1> [Polyether Polyol (A-1)] In a stainless steel autoclave equipped with a stirring device and temperature control device, 500 parts by weight of PTMG-1000 [manufactured by Mitsubishi Chemical Corporation] and 2 parts by weight of potassium hydroxide were charged, stirring was started, nitrogen was purged, and the autoclave pressure was reduced to 0.005 MPa. The mixture was heated to 130°C, and 500 parts by weight of PO was continuously added while controlling the reaction temperature to maintain it at 125-130°C. Subsequently, it was aged at 130°C for 1 hour. Next, 20 parts by weight of synthetic silicate [manufactured by Kyowa Chemical Industry Co., Ltd.; "Kyoward 600"] and 20 parts by weight of water were added, and the mixture was treated at 80°C for 2 hours. After removal from the autoclave, the mixture was filtered through a 1 μm filter, and then dehydrated at 130°C and a pressure of 3.0 kPa for 2 hours. Liquid polyether polyol (A-1) was obtained. The hydroxyl value of (A-1) was 53.1 mgKOH / g, the ratio of the average degree of polymerization of the oxytetramethylene group to the average degree of polymerization of the oxyalkylene group was 42:58, m was 19.2, and n was 13.9.

[0052] <Manufacturing Example 2> [Polyether Polyol (A-2)] In a stainless steel autoclave equipped with a stirring device and temperature control device, 759 parts by weight of PTMG-1300 [manufactured by Mitsubishi Chemical Corporation] and 0.06 parts by weight of DMC catalyst were charged, stirring was started, nitrogen was purged, and the autoclave was reduced to a pressure of 0.005 MPa. The mixture was heated to 130°C, and 91 parts by weight of PO3 were continuously added while controlling the reaction temperature to maintain it at 125-130°C. Subsequently, the mixture was aged at 130°C for 1 hour to obtain liquid polyether polyol (A-2). The hydroxyl value of (A-2) was 55.1 mgKOH / g, the ratio of the average degree of polymerization of oxytetramethylene groups to the average degree of polymerization of oxyalkylene groups was 59:41, m was 12.7, and n was 18.1.

[0053] <Manufacturing Example 3> [Polyether Polyol (A-3)] In a stainless steel autoclave equipped with a stirring device and temperature control device, 853 parts by weight of PTMG-1500 [manufactured by Mitsubishi Chemical Corporation] and 0.06 parts by weight of DMC catalyst were charged, stirring was started, nitrogen was purged, and the autoclave was reduced to a pressure of 0.005 MPa. The mixture was heated to 130°C, and 97 parts by weight of PO2 were continuously added while controlling the reaction temperature to maintain it at 125-130°C. Subsequently, the mixture was aged at 130°C for 1 hour to obtain liquid polyether polyol (A-3). The hydroxyl value of (A-3) was 54.5 mgKOH / g, the ratio of the average degree of polymerization of oxytetramethylene groups to the average degree of polymerization of oxyalkylene groups was 68:32, m was 9.6, and n was 20.8.

[0054] <Manufacturing Example 4> [Polyether Polyol (A-4)] In a stainless steel autoclave equipped with a stirring device and temperature control device, 500 parts by weight of PTMG-1000 [manufactured by Mitsubishi Chemical Corporation] and 2 parts by weight of potassium hydroxide were charged, stirring was started, nitrogen was purged, and the autoclave was reduced to a pressure of 0.005 MPa. The mixture was heated to 130°C, and 500 parts by weight of EO were continuously added while controlling the reaction temperature to maintain it at 125-130°C. Subsequently, the mixture was aged at 130°C for 1 hour. Next, 20 parts by weight of synthetic silicate [manufactured by Kyowa Chemical Industry Co., Ltd.; "Kyoward 600"] and 20 parts by weight of water were added, and the mixture was treated at 80°C for 2 hours. After removal from the autoclave, the mixture was filtered through a 1 μm filter, and then dehydrated at 130°C and a pressure of 3.0 kPa for 2 hours. Liquid polyether polyol (A-4) was obtained. The hydroxyl value of (A-4) was 56.3 mgKOH / g, the ratio of the average degree of polymerization of the oxytetramethylene group to the average degree of polymerization of the oxyalkylene group was 38:62, m was 22.6, and n was 13.9.

[0055] <Manufacturing Example 5> [Polyether Polyol (A-5)] In a stainless steel autoclave equipped with a stirring device and temperature control device, 374 parts by weight of PTMG-650 [manufactured by Mitsubishi Chemical Corporation] and 0.06 parts by weight of DMC catalyst were charged, stirring was started, nitrogen was purged, and the autoclave was reduced to a pressure of 0.005 MPa. The mixture was heated to 130°C, and 76 parts by weight of PO7 were continuously added while controlling the reaction temperature to maintain it at 125-130°C. Subsequently, the mixture was aged at 130°C for 1 hour to obtain liquid polyether polyol (A-5). The hydroxyl value of (A-5) was 55.5 mgKOH / g, the ratio of the average degree of polymerization of oxytetramethylene groups to the average degree of polymerization of oxyalkylene groups was 28:72, m was 23.6, and n was 9.0.

[0056] <Manufacturing Example 6> [Polyether Polyol (A-6)] In a stainless steel autoclave equipped with a stirring device and temperature control device, 500 parts by weight of PTMG-1000 [manufactured by Mitsubishi Chemical Corporation] and 2 parts by weight of potassium hydroxide were charged, stirring was started, nitrogen was purged, and the autoclave was reduced to a pressure of 0.005 MPa. The autoclave was heated to 130°C, and 500 parts by weight of a mixture of PO and EO in a molar ratio of 1:1 was continuously added while controlling the reaction temperature to maintain it at 125-130°C. Subsequently, it was aged at 130°C for 1 hour. Next, 20 parts by weight of synthetic silicate [manufactured by Kyowa Chemical Industry Co., Ltd.; "Kyoward 600"] and 20 parts by weight of water were added, and the mixture was treated at 80°C for 2 hours. After removal from the autoclave, it was filtered through a 1 μm filter, and then dehydrated at 130°C and a pressure of 3.0 kPa for 2 hours. Liquid polyether polyol (A-6) was obtained. The hydroxyl value of (A-6) was 55.2 mgKOH / g, the ratio of the average degree of polymerization of the oxytetramethylene group to the average degree of polymerization of the oxyalkylene group was 41:59, m was 20.2, and n was 13.9.

[0057] <Manufacturing Example 7> [Polyether Polyol (A-7)] In a stainless steel autoclave equipped with a stirring device and temperature control device, 500 parts by weight of PTMG-650 [manufactured by Mitsubishi Chemical Corporation] and 2 parts by weight of potassium hydroxide were charged, stirring was started, nitrogen was purged, and the autoclave was reduced to a pressure of 0.005 MPa. The autoclave was heated to 130°C, and 500 parts by weight of a mixture of PO and EO in a molar ratio of 1:1 was continuously added while controlling the reaction temperature to maintain it at 125-130°C. Subsequently, it was aged at 130°C for 1 hour. Next, 20 parts by weight of synthetic silicate [manufactured by Kyowa Chemical Industry Co., Ltd.; "Kyoward 600"] and 20 parts by weight of water were added, and the mixture was treated at 80°C for 2 hours. After removal from the autoclave, it was filtered through a 1 μm filter, and then dehydrated at 130°C and a pressure of 3.0 kPa for 2 hours. Liquid polyether polyol (A-7) was obtained. The hydroxyl value of (A-7) was 84.2 mgKOH / g, the ratio of the average degree of polymerization of the oxytetramethylene group to the average degree of polymerization of the oxyalkylene group was 40:60, m was 13.4, and n was 9.0.

[0058] <Comparative Manufacturing Example 1> For comparison, commercially available Sannix PP-2000 [polypropylene glycol with Mn=2,000, manufactured by Sanyo Chemical Industries, Ltd.] was used as is as polyether polyol (A'-1).

[0059] <Comparative Manufacturing Example 2> For comparison, commercially available PTMG-2000 [poly(oxytetramethylene) glycol with Mn=2,000, manufactured by Mitsubishi Chemical Corporation] was used as is as polyether polyol (A'-2).

[0060] <Comparative Manufacturing Example 3> [Polyether Polyol (A'-3)] In a stainless steel autoclave equipped with a stirring device and temperature control device, 125 parts by weight of PTMG-250 [manufactured by Mitsubishi Chemical Corporation] and 0.06 parts by weight of DMC catalyst were charged, stirring was started, nitrogen was purged, and the autoclave was reduced to a pressure of 0.005 MPa. The mixture was heated to 130°C, and 75 parts by weight of PO8 were continuously added while controlling the reaction temperature to maintain it at 125-130°C. Subsequently, the mixture was aged at 130°C for 1 hour to obtain liquid polyether polyol (A'-3). The hydroxyl value of (A'-3) was 56.1 mgKOH / g, the ratio of the average degree of polymerization of oxytetramethylene groups to the average degree of polymerization of oxyalkylene groups was 10:90, m was 30.2, and n was 3.5.

[0061] <Comparative Manufacturing Example 4> [Polyether Polyol (A'-4)] In a stainless steel autoclave equipped with a stirring device and temperature control device, 900 parts by weight of PTMG-1800 [manufactured by Mitsubishi Chemical Corporation] and 0.06 parts by weight of DMC catalyst were charged, stirring was started, nitrogen was purged, and the autoclave was reduced to a pressure of 0.005 MPa. The mixture was heated to 130°C, and 100 parts by weight of PO was continuously added while controlling the reaction temperature to maintain it at 125-130°C. Subsequently, the mixture was aged at 130°C for 1 hour to obtain liquid polyether polyol (A'-4). The hydroxyl value of (A'-4) was 56.2 mgKOH / g, the ratio of the average degree of polymerization of oxytetramethylene groups to the average degree of polymerization of oxyalkylene groups was 88:12, m was 3.4, and n was 25.0.

[0062] Table 1 summarizes the hydroxyl value, average degree of polymerization of the oxytetramethylene group (n), average degree of polymerization of the oxyalkylene group with 2 to 3 carbon atoms (m), and their ratio (n:m) for the polyether polyols of Production Examples 1-7 and Comparative Production Examples 3-4.

[0063] [Table 1]

[0064] <Examples 1-7 and Comparative Examples 1-4> For the polyether polyols of Production Examples 1-7 and Comparative Production Examples 1-4, urethane prepolymers (P-1)-(P-7), (P'-1)-(P'-4) and polyurethane resin films (Q-1)-(Q-7), (Q'-1)-(Q'-4) were prepared by the following method, and various physical properties and evaluation results are shown in Tables 2 and 3. The measurement and evaluation methods for various physical properties in this invention are as follows.

[0065] <Preparation of urethane prepolymer (P-1) and polyurethane resin film (Q-1)> In a reactor equipped with a stirrer and a heating reactor, the polyether polyol (A-1) obtained in Production Example 1, along with Sannix GP-1500 [manufactured by Sanyo Chemical Industries, Ltd.], 1,4-butanediol [manufactured by Mitsubishi Chemical Corporation], isophorone diisocyanate [manufactured by Tokyo Chemical Industries, Ltd.], and Neostan U-100 [manufactured by Nitto Chemical Co., Ltd.] were added in the quantities shown in Table 2. The mixture was stirred at 100°C for 6 hours to obtain urethane prepolymer (P-1). The NCO concentration, urethane group content, and viscosity of the obtained urethane prepolymer (P-1), measured by the method described below, are shown in Table 2. A polyurethane prepolymer (P-1) and 1,4-butanediol as a chain extender were blended in the amounts shown in Table 3, homogeneously mixed at 100°C, degassed by centrifugal force, molded into a 1 mm thick sheet, and cured at 80°C for 1 day to obtain a polyurethane resin film (Q-1). The obtained polyurethane resin film (Q-1) was measured for tensile strength, elongation at break, tensile strength after weathering test, and appearance after weathering test using the following method, and the results are shown in Table 3.

[0066] <Preparation of urethane prepolymers (P-2) to (P-7), (P'-1) to (P'-4) and polyurethane resin films (Q-2) to (Q-7), (Q'-1) to (Q'-4)> Except for using the raw materials listed in Tables 2 and 3, the same procedure was used for the preparation of (P-1) and (Q-1) to obtain urethane prepolymers (P-2) to (P-7), comparative urethane prepolymers (P'-1) to (P'-4), polyurethane resin films (Q-2) to (Q-7), and comparative polyurethane resin films (Q'-1) to (Q'-4), respectively, using polyether polyols (A-2) to (A-7), Sannix PP-2000 [manufactured by Sanyo Chemical Industries, Ltd.], PTMG-2000 [manufactured by Mitsubishi Chemical Corporation], A'-3, and A'-4. The NCO concentration, urethane group content, and viscosity of the obtained urethane prepolymers (P-2) to (P-7) and comparative urethane prepolymers (P'-1) to (P'-4) are shown in Table 2. Furthermore, Table 3 shows the tensile strength, elongation at break, tensile strength after weathering, and appearance after weathering for polyurethane resin films (Q-2) to (Q-7) and comparative polyurethane resin films (Q'-1) to (Q'-4).

[0067] <Viscosity of urethane prepolymer> The urethane prepolymer was temperature-controlled in a 25°C constant temperature bath, and the viscosity was measured using a BL-type rotational viscometer (manufactured by Toki Sangyo Co., Ltd.) with rotor No. 4 under a 25°C atmosphere.

[0068] <Tensile strength and elongation at break of polyurethane resin film> Test specimens were prepared from polyurethane resin film in a dumbbell shape (size 3). Using a tensile testing machine, the breaking strength (in MPa) and elongation at breaking (in %) were measured under conditions of 23°C, 50% RH, and a tensile speed of 100 mm / min. Measurements were performed on five test specimens, and the average value was evaluated.

[0069] <Tensile strength and appearance of polyurethane resin film after weathering test> After a 500-hour weathering test was conducted on a polyurethane resin film using a xenon weather meter, dumbbell-shaped test specimens (size 3) were prepared from the polyurethane resin film. The breaking strength (in MPa) was measured using a tensile testing machine at 23°C, 50% RH, and a tensile speed of 100 mm / min. Measurements were performed on five test specimens, and the average value was evaluated. In addition, the appearance after the weathering test was visually evaluated for the presence or absence of cracks.

[0070] [Table 2]

[0071] [Table 3]

[0072] As shown in Tables 2 and 3, in all of the examples of the present invention (Examples 1 to 7), the viscosity of the urethane prepolymer, which is the precursor, was within an appropriate range, resulting in good handling properties. Furthermore, the obtained polyurethane resin films exhibited good tensile strength and elongation at break, and even after weathering tests, the decrease in tensile strength was suppressed, and no deterioration in appearance (cracking) was observed. In contrast, Comparative Examples 1 and 3 showed deterioration in appearance (cracking) after the weathering test, and their tensile strength also decreased after the weathering test. Furthermore, Comparative Examples 2 and 4 had high viscosity urethane prepolymers, resulting in reduced handling properties. From these results, it was confirmed that by using the polyol composition for polyurethane resins of the present invention, it is possible to obtain a polyurethane resin with excellent handling properties for the precursor urethane prepolymer, as well as excellent resin strength and weather resistance. [Industrial applicability]

[0073] The polyurethane resin of the present invention exhibits excellent resin strength and weather resistance, making it suitable for use as a coating material, adhesive, or sealant. Furthermore, by using the polyol composition for polyurethane resin of the present invention, it is possible to provide a polyurethane resin that exhibits excellent handling properties of the precursor urethane prepolymer, as well as excellent resin strength and weather resistance, making it suitable for use in non-porous, moisture-permeable material applications.

Claims

1. A polyol composition for polyurethane resins containing a divalent polyether polyol (A), which is a copolymer having segments of oxytetramethylene groups at both ends and segments of oxyalkylene groups having 2 to 3 carbon atoms, wherein the average degree of polymerization (m) of the oxyalkylene groups having 2 to 3 carbon atoms is 9.0 to 24.0, and the ratio (n:m) of the average degree of polymerization (n) of the oxytetramethylene groups in the copolymer to the average degree of polymerization (m) of the oxyalkylene groups having 2 to 3 carbon atoms is 25:75 to 70:

30.

2. The polyol composition for polyurethane resin according to claim 1, wherein the average degree of polymerization (n) of the oxytetramethylene groups in the copolymer is a number from 4.0 to 30.

0.

3. The polyol composition for polyurethane resins according to claim 1 or 2, wherein the hydroxyl value of the divalent polyether polyol (A) is 50 to 90 mg KOH / g.

4. The polyol composition for polyurethane resin according to claim 1 or 2, wherein the content of the divalent polyether polyol (A) in the polyol composition for polyurethane resin is 10 to 90% by weight based on the total weight of the polyol components.

5. A polyurethane resin obtained by reacting a polyol component and a polyisocyanate component of the polyol composition for polyurethane resins according to claim 1 or 2.

Images