Silicone polyether polyol and method for producing same

Abstract

The present invention provides silicone polyether polyol that is less likely to contain moisture and a method for producing the same. This silicone polyether polyol is produced by reacting an initiator, which is polysiloxane that has a molecular weight distribution of 1.50 or less and that has an OH group at an end thereof, and alkylene oxide in the presence of a catalyst.

Description

Silicone polyether polyol and method for producing same

[0001] The present invention relates to a method for producing a silicone polyether polyol and to a silicone polyether polyol.

[0002] For example, as disclosed in Patent Document 1, a technique is known in which a polyoxyalkylene compound (silicone polyether polyol) is produced by ring-opening addition polymerization of an alkylene oxide with an organopolysiloxane compound as an initiator.

[0003] Japanese Patent Application Publication No. 4-227925

[0004] However, the silicone polyether polyol described in Patent Document 1 is prone to absorb moisture, and there is a problem in that the silicone polyether polyol absorbs moisture during storage, making it difficult to handle.

[0005] An object of the present invention is to provide a silicone polyether polyol that is less likely to absorb moisture and a method for producing the same.

[0006] The present invention relates to the following items [1] to [9]. [1] A method for producing a silicone polyether polyol, comprising reacting an initiator, which is a polysiloxane having a molecular weight distribution of 1.50 or less and having terminal OH groups, with an alkylene oxide in the presence of a catalyst. [2] A method for producing a silicone polyether polyol according to item [1], wherein the catalyst is a double metal cyanide complex. [3] A method for producing a silicone polyether polyol according to item [1] or [2], wherein the polysiloxane has a number-average molecular weight of 800 or more and 15,000 or less. [4] A method for producing a silicone polyether polyol according to any of items [1] to [3], wherein the polysiloxane is a linear molecule having two OH groups at one end. [5] A method for producing a silicone polyether polyol according to any of items [1] to [4], wherein the alkylene oxide comprises propylene oxide. [6] A method for producing a silicone polyether polyol according to any of items [1] to [5], wherein the silicone polyether polyol has a number-average molecular weight of 1,000 or more and 50,000 or less. [7] The method for producing a silicone polyether polyol according to any one of [1] to [6], wherein the silicone polyether polyol has a molecular weight distribution of 1.50 or less. [8] The method for producing a silicone polyether polyol according to any one of [1] to [7], wherein the proportion of molecules having a molecular weight of 750 or less is 1.0% or less.

[0007] [9] A silicone polyether polyol having a number average molecular weight of 1,000 or more and 50,000 or less, wherein the silicone polyether polyol has a water content of 200 ppm by mass or less, and after being left to stand for one day in an atmosphere at a temperature of 25°C and a relative humidity of 40%, the water content is 6,000 ppm by mass or less.

[0008] According to the present invention, a silicone polyether polyol that is less likely to absorb moisture can be obtained.

[0009] Preferred embodiments of the present invention will be described in detail below. Note that the present invention is not limited to these embodiments, and when there are multiple embodiments, the present invention also includes combinations of the embodiments. Numerical values ​​include the range of rounding.

[0010] The definitions and meanings of the terms used in this specification are as follows: "Mn" is the number average molecular weight. "Mw" is the weight average molecular weight. Mn and Mw are determined by the method described in the Examples. The molecular weight distribution is a value calculated from Mw and Mn, and is the ratio of Mw to Mn. Hereinafter, the molecular weight distribution will also be referred to as "Mw / Mn." The term "OH group at the terminal of a polysiloxane" refers to the OH group possessed by an organic group bonded to a silicon atom at the terminal of a siloxane bond. The term "double-terminal OH group structure" of a polysiloxane refers to a polysiloxane that is a linear molecule having one OH group at one terminal and one OH group at the other terminal. The term "single-terminal OH group structure" of a polysiloxane refers to a polysiloxane that is a linear molecule having two or more OH groups at one terminal and no OH group at the other terminal. The low molecular weight component of the silicone polyether polyol refers to a component having a molecular weight of 750 or less, and may also contain unreacted polysiloxane. "Not easily absorbs moisture" refers to being less likely to absorb moisture over time in an atmospheric environment. The hydroxyl value is determined by the method described in the Examples. The moisture content is determined by the method described in the Examples.

[0011] The method for producing a silicone polyether polyol of the present invention (the present production method) involves reacting an initiator, which is a polysiloxane having a Mw / Mn ratio of 1.50 or less and terminal OH groups, with an alkylene oxide in the presence of a catalyst to produce a polymeric silicone polyether polyol. In this production method, the alkylene oxide undergoes ring-opening addition polymerization with the terminal OH groups of the polysiloxane. This results in polyoxyalkylene chains extending from the terminals of the polysiloxane, yielding a silicone polyether polyol.

[0012] (Alkylene Oxide) The alkylene oxide used in the present production method can also be referred to as a cyclic ether, and is not particularly limited as long as it is capable of undergoing ring-opening addition polymerization with OH groups of a polysiloxane, as described below. For example, from the viewpoint of reactivity, the alkylene oxide used in the present production method preferably has 2 to 4 carbon atoms. Examples of alkylene oxides include ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, epichlorohydrin, oxetane, styrene oxide, 2,3-epoxy-1-propanol, and allyl glycidyl ether. Among these, the alkylene oxide preferably contains ethylene oxide or propylene oxide, and more preferably contains propylene oxide. In the present production method, one type of alkylene oxide may be used alone, or two or more types of alkylene oxides may be used in combination.

[0013] (Polysiloxane) Polysiloxane is a polymer having a siloxane bond in the backbone. The polysiloxane used as an initiator in this production method has an Mw / Mn ratio of 1.50 or less and has OH groups at the terminals. By using such a polysiloxane as an initiator, a silicone polyether polyol that is less likely to absorb moisture can be produced.

[0014] The polysiloxane used in this production method is not particularly limited as long as it has an Mw / Mn ratio of 1.50 or less and has terminal OH groups. For example, the number of carbon atoms in the polysiloxane used in this production method may be any number, with no upper limit, but preferably, for example, 1 or more. Furthermore, the polysiloxane used in this production method may have any number of terminal OH groups. For example, the polysiloxane may have a structure with OH groups at both ends, or a structure with OH groups at only one end. In this production method, in order to obtain a silicone polyether polyol that is less likely to absorb water, it is more preferable to use a polysiloxane with a structure with an OH group at only one end. More specifically, by using a polysiloxane with a structure with an OH group at only one end and an Mw / Mn ratio of 1.50 or less, the silicone polyether polyol is less likely to absorb water, making the silicone polyether polyol easier to handle after storage. The polysiloxane may contain functional groups other than OH groups.

[0015] The polysiloxane used in the present production method preferably has a structure represented by formula (1) or formula (2), and more preferably has a structure represented by formula (1).

[0016]

[0017]

[0018] Formula (1) shows an example of a structure having an OH group at one end, and formula (2) shows an example of a structure having OH groups at both ends. １ , R ２ , R ３ , R ４ , R ６ , R ７ is a hydrocarbon group having one or more carbon atoms, preferably a hydrocarbon group having 1 to 5 carbon atoms, and more preferably a methyl group. １ , R ２ , R ３ , R ４ , R ６ , R ７ The carbon numbers of R in formula (1) may be the same or different. ５is a hydrocarbon group having one or more carbon atoms, preferably a hydrocarbon group having 1 to 5 carbon atoms, and more preferably a butyl group. ５ may have a functional group other than an OH group. n in formulas (1) and (2) is an integer of 1 or more, more preferably 1 to 500. X in formula (1) is a hydrocarbon group having two OH groups at its terminal. The number of carbon atoms in X is 1 or more. X may have a functional group other than an OH group in addition to the two OH groups. Examples of functional groups other than an OH group include an ether group and an ester group, and an ether group is preferred. Y in formula (2) １ , Y ２ is a hydrocarbon group having one OH group at the end. １ , Y ２ has one or more carbon atoms; and Y １ , Y ２ The carbon numbers of the groups Y may be the same or different. １ , Y ２ may have a functional group other than the OH group in addition to one OH group. Examples of the functional group other than the OH group include an ether group and an ester group, and an ether group is preferred.

[0019] Specific examples of polysiloxanes used in this production method include α-butyl-ω-{3-[2,2-bis(hydroxymethyl)butoxy]propyl}polydimethylsiloxane (product names: Silaplane FM-DA11, FM-DA21, FM-DA26, manufactured by JNC Corporation) and diol-modified organosiloxane (product names: X-22-176DX, X-22-176GX-A, manufactured by Shin-Etsu Chemical Co., Ltd.).

[0020] In the present production method, the polysiloxane may be used alone or in combination of two or more kinds.

[0021] The Mn of the polysiloxane is preferably from 800 to 15,000, more preferably from 900 to 12,000, and even more preferably from 1,000 to 8,000. When the Mn of the polysiloxane is within this range, a silicone polyether polyol can be produced that has good viscosity, is easy to handle, and is less likely to absorb moisture.

[0022] The Mw / Mn of the polysiloxane is 1.50 or less, preferably 1.01 to 1.50, more preferably 1.05 to 1.50, and even more preferably 1.10 to 1.40. When the Mw / Mn of the polysiloxane is in this range, a silicone polyether polyol that is less likely to absorb moisture can be produced.

[0023] (Relationship between alkylene oxide and polysiloxane) The ratio of Mn of the polyoxyalkylene chain (the portion composed of structural units based on alkylene oxide) of the silicone polyether polyol to Mn of the polysiloxane (Mn of polyoxyalkylene chain / Mn of polysiloxane; hereinafter also referred to as molecular weight ratio) is preferably 0.10 or more and 50.00 or less, more preferably 0.20 or more and 20.00 or less, and even more preferably 0.25 or more and 10.00 or less. By setting the molecular weight ratio within this range, a silicone polyether polyol that is less likely to absorb moisture can be produced. The Mn of the polyoxyalkylene chain can be calculated by subtracting the Mn of the polysiloxane from the Mn of the silicone polyether polyol.

[0024] (Catalyst) In the present production method, it is preferable to use a composite metal cyanide complex catalyst (also referred to as a "DMC catalyst") as a catalyst to react (ring-opening addition polymerization) an alkylene oxide to produce a silicone polyether polyol. That is, for example, a method is preferred in which an alkylene oxide is reacted in a reaction vessel using a polysiloxane as an initiator in the presence of a DMC catalyst.

[0025] When a DMC catalyst is used as the catalyst, a silicone polyether polyol with a narrow Mw / Mn and lower viscosity can be obtained. Examples of DMC catalysts include zinc hexacyanocobaltate complexes in which the ligand is t-butyl alcohol (hereinafter referred to as "TBA-DMC catalysts"), zinc hexacyanocobaltate complexes in which the ligand is ethylene glycol dimethyl ether (glyme), and zinc hexacyanocobaltate complexes in which the ligand is diethylene glycol dimethyl ether (diglyme). One type of DMC catalyst may be used alone, or two or more types may be used in combination. Among these, TBA-DMC catalysts are preferred. The use of a TBA-DMC catalyst increases activity during polymerization, thereby enabling the molecular weight distribution Mw / Mn of the silicone polyether polyol to be narrowed. Furthermore, when a TBA-DMC catalyst is used, alkylene oxide is preferentially added to low-molecular-weight polysiloxanes among the polysiloxanes in the initiator, resulting in a lower content of low-molecular-weight components in the produced silicone polyether polyol. A silicone polyether polyol with a low content of low-molecular-weight components is less likely to absorb moisture. As a result, it is easier to obtain a silicone polyether polyol that is lower in viscosity, less likely to absorb moisture, and easier to handle.

[0026] The method for producing the DMC catalyst is not particularly limited. Various methods for producing the DMC catalyst can be used. For example, the methods described in paragraphs 0031 to 0034 of JP 2005-179567 A can be mentioned. The method for activating the DMC catalyst is also not particularly limited. For example, unused DMC catalyst may be mixed with alkylene oxide in a reactor to activate the DMC catalyst.

[0027] (Production Conditions) Next, preferred production conditions for silicone polyether polyol will be described.

[0028] The amount of catalyst used may be any amount necessary for the reaction of alkylene oxide. However, it is preferable to use as little catalyst as possible. The smaller the amount of catalyst used, the less catalyst will be mixed into the product silicone polyether polyol. Therefore, when a resin composition is produced using a silicone polyether polyol, the effect of the catalyst on the reactivity of the resin composition can be easily reduced. Furthermore, the effect of the catalyst on the physical properties of the resin composition produced using the silicone polyether polyol as a raw material can be easily reduced.

[0029] For example, it is preferable to use a DMC catalyst in an amount such that the solid catalyst component of the DMC catalyst is 10 ppm by mass or more in the silicone polyether polyol immediately after polymerization.When the solid catalyst component of the DMC catalyst is 10 ppm by mass or more, sufficient polymerization catalyst activity is easily obtained.Although the upper limit of the amount of the DMC catalyst used is not particularly limited, when the solid catalyst component of the DMC catalyst is 100 ppm by mass or less, the amount used can be reduced, which is advantageous in terms of production costs.In addition, it is easy to reduce the remaining amount of the DMC catalyst.In addition, the solid catalyst component of the DMC catalyst is a component excluding the alkylene oxide used to activate the catalytic action and excess ligand.

[0030] (Reaction) The temperature of the reaction (ring-opening addition polymerization) is not particularly limited. The temperature range is, for example, preferably 30°C or higher and 180°C or lower, more preferably 70°C or higher and 160°C or lower, and even more preferably 90°C or higher and 140°C or lower. When the reaction temperature is higher than the lower limit of the above-mentioned numerical range, ring-opening addition polymerization is likely to start. When the reaction temperature is lower than the upper limit of the above-mentioned numerical range, the catalytic activity of the DMC catalyst for the polymerization reaction is likely to be sufficiently maintained.

[0031] The reaction is preferably carried out under sufficient stirring conditions. In the case of a stirring method using a general stirring blade, it is preferable to make the rotation speed of the stirring blade as fast as possible. However, it is preferable to make the rotation speed of the stirring blade as fast as possible within a range in which the stirring efficiency is not reduced by taking in a large amount of gas from the gas phase into the reaction liquid.

[0032] In order to reduce the Mw / Mn of the silicone polyether polyol, it is preferable to slow the supply rate of alkylene oxide into the reaction vessel as much as possible. However, slowing the supply rate tends to reduce production efficiency. Therefore, it is preferable to determine the supply rate of alkylene oxide by comparing and balancing Mw / Mn and production efficiency.

[0033] A reaction solvent may be used in the reaction. Examples of the reaction solvent include aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; organic halogens such as chloroform and dichloromethane; and ethers such as tetrahydrofuran and dioxane. One reaction solvent may be used alone, or two or more reaction solvents may be used in combination. Among these, hexane and tetrahydrofuran are preferred because they have a low boiling point and are easy to remove after completion of the reaction.

[0034] After the reaction is complete, the DMC catalyst may be removed from the silicone polyether polyol product. However, if the amount of DMC catalyst remaining in the silicone polyether polyol is small and the subsequent effects can be ignored, the removal of the DMC catalyst may be omitted from the standpoint of production efficiency, etc.

[0035] The method for removing the DMC catalyst is not particularly limited. For example, the following methods can be used: - A method in which the DMC catalyst is adsorbed using an adsorbent, and then the adsorbent with the adsorbed DMC catalyst is removed by filtration; - A method in which the DMC catalyst is neutralized using a neutralizing agent, and then the neutralized DMC catalyst is removed by filtration. Examples of adsorbents include synthetic silicates, ion exchange resins, and activated clay. Examples of synthetic silicates include magnesium silicate and aluminum silicate. Examples of neutralizing agents include amines, alkali metal hydroxides, organic acids, and mineral acids.

[0036] In the reaction, the molar ratio of alkylene oxide to polysiloxane is preferably 0.1 or more and 100 or less, more preferably 0.2 or more and 200 or less, and even more preferably 0.3 or more and 150 or less. When the molar ratio is within this range, it is easy to obtain a silicone polyether polyol that is less likely to absorb moisture. The molar ratio of alkylene oxide to polysiloxane is the value obtained by dividing the amount of alkylene oxide (mol) by the amount of polysiloxane (mol).

[0037] In this production method, various additives such as antioxidants, anticorrosives, and pH adjusters may be used. For example, adding an antioxidant or anticorrosive can help prevent the silicone polyether polyol from deteriorating during long-term storage. For example, using a pH adjuster can help control the reaction during the production of the silicone polyether polyol. Furthermore, it can help control the reactivity when using the resulting silicone polyether polyol to produce a resin composition. Examples of pH adjusters include phosphoric acid.

[0038] (Silicone Polyether Polyol) The silicone polyether polyol according to this embodiment is a polymer obtained by reacting an alkylene oxide with a polysiloxane as an initiator in the presence of a catalyst. The silicone polyether polyol has a polysiloxane-based structural unit and an alkylene oxide-based structural unit. The silicone polyether polyol according to this embodiment is a silicone polyether polyol having an Mn of 1,000 or more and 50,000 or less, and having a moisture content of 200 ppm by mass or less. After the silicone polyether polyol is left standing for one day in an atmosphere at a temperature of 25°C and a relative humidity of 40%, the moisture content is 6,000 ppm by mass or less. The polysiloxane-based structural unit is a structural unit having a siloxane bond in its skeleton, and corresponds to a partial structure obtained by removing the terminal OH group from the polysiloxane initiator. The alkylene oxide-based structural unit constitutes a polyoxyalkylene chain. The oxyalkylene chain structural unit is typically (C ｍ H ２ｍO) (m is an integer of 1 or more). The polyoxyalkylene chain may be linear or branched. The polyoxyalkylene chain may be a homopolymer of one type of alkylene oxide, or a block copolymer or random copolymer of two or more types of alkylene oxide. The polyoxyalkylene chain may have a halogen atom, an aromatic ring, or an allyl group derived from the alkylene oxide.

[0039] The proportion of alkylene oxide-based structural units in the silicone polyether polyol is preferably 5% by mass or more and 95% by mass or less, more preferably 10% by mass or more and 90% by mass or less, and even more preferably 20% by mass or more and 80% by mass or less, relative to 100% by mass of the silicone polyether polyol. When the proportion of alkylene oxide-based structural units is within this range, a silicone polyether polyol that is less likely to absorb moisture can be obtained. The proportion of alkylene oxide-based structural units in the silicone polyether polyol is determined by the amount of alkylene oxide added relative to the molecular weight of the polysiloxane.

[0040] The Mn of the silicone polyether polyol is preferably from 1,000 to 50,000, more preferably from 1,000 to 40,000, and even more preferably from 1,000 to 30,000. When the Mn of the silicone polyether polyol is within this range, a silicone polyether polyol that is less likely to absorb moisture can be obtained.

[0041] The Mw / Mn of the silicone polyether polyol is preferably 1.00 or more, more preferably 1.05 or more. Also, it is preferably 1.50 or less, more preferably 1.40 or less, and even more preferably 1.30 or less. When the Mw / Mn of the silicone polyether polyol is within this range, a silicone polyether polyol having a low content of low molecular weight components and less moisture absorption can be obtained.

[0042] The silicone polyether polyol according to this embodiment has the following property: When a silicone polyether polyol having a moisture content of 200 ppm by mass or less is allowed to stand for one day in an atmosphere at a temperature of 25°C and a relative humidity of 40%, the moisture content is 6000 ppm by mass or less. A silicone polyether polyol having the above property can be said to be a silicone polyether polyol that is less likely to absorb moisture.

[0043] The evaluation of these properties will be described in detail below. 30 g of silicone polyether polyol with a water content of 200 mass ppm or less is placed in a 50 mL glass vial (mouth inner diameter approximately 20 mm) and left to stand for 1 day (24 hours) in an atmosphere at 25°C and 40% relative humidity, after which the water content of the silicone polyether polyol is measured and defined as the water content after 1 day. The water content of the silicone polyether polyol after 1 day is preferably 6000 mass ppm or less, more preferably 5900 mass ppm or less, and even more preferably 5800 mass ppm or less. When the water content after 1 day is within this range, a silicone polyether polyol that is less likely to contain water can be obtained. The water content can be measured by the method described in the examples.

[0044] Furthermore, a silicone polyether polyol having a water content of 200 ppm by mass or less is mixed with 26% by mass saturated saline at room temperature (25 ° C.) at a volume ratio of 1:1, and then allowed to stand for 10 minutes to allow phase separation. The water content of the upper layer (a layer mainly composed of silicone polyether polyol) is referred to as the upper layer water content. Here, phase separation refers to separation into an upper layer and a lower layer (aqueous layer). The saturated saline is used to make it easier to confirm phase separation. The upper layer water content is preferably 6000 ppm by mass or less, and the lower the better. When the upper layer water content is within this range, the silicone polyether polyol can be said to be less likely to absorb water even when in contact with or mixed with water. Such silicone polyether polyols are easy to separate and less likely to absorb water in industrial separation tank-type oil-water separation processes, and are therefore easy to handle.

[0045] Furthermore, it is preferable that no phase separation occurs after placing 30 g of silicone polyether polyol in a 50 mL glass vial (inner diameter of mouth: approximately 20 mm) and leaving it to stand for 2 days (48 hours) in an atmosphere at a temperature of 25°C and a relative humidity of 40%. A silicone polyether polyol that does not undergo phase separation is less likely to absorb moisture and can be said to have excellent storage stability.

[0046] The content of low molecular weight components in the silicone polyether polyol is preferably 2.0% or less, more preferably 1.0% or less, and even more preferably 0.9% or less. The content of low molecular weight components in the silicone polyether polyol is the ratio of the area of ​​"peaks with a molecular weight of 750 or less of the silicone polyether polyol" to the area of ​​"all peaks of the silicone polyether polyol" in GPC analysis of the silicone polyether polyol. The content of low molecular weight components in the silicone polyether polyol falling within the above range means that the content of low molecular weight components in the silicone polyether polyol is low.

[0047] For example, by using a DMC catalyst as an initiator and adding propylene oxide (hereinafter also referred to as "PO"), PO is preferentially added to low-molecular-weight siloxanes among the polysiloxanes of the initiator, and a silicone polyether polyol with a reduced content of low-molecular-weight components is obtained.

[0048] The low content of low molecular weight components in silicone polyether polyols makes it difficult for the silicone polyether polyol to absorb moisture, and products using the silicone polyether polyols are more likely to achieve good functionality and appearance.In addition, since such silicone polyether polyols are less likely to volatilize low molecular weight components or produce insulating substances such as silica, they can be suitably used in the electrical and electronic fields.They can also be suitably used in building materials, etc., where a reduction in low molecular weight components, which can cause stains around joints, is required.

[0049] The silicone polyether polyols of the present invention are particularly useful as thermoplastic resins, photocurable resins, raw materials for sealants or foams, or as resin modifiers.

[0050] Next, examples will be described. Note that the embodiment may be modified as long as the effects of the invention are achieved.

[0051] [Measurement Method] The measurement method used in the examples will be explained.

[0052] (Hydroxyl Value) The hydroxyl value (mgKOH / g) of the silicone polyether polyol produced in each example was analyzed by the hydroxyl value measurement method in accordance with JIS K1557:2007.

[0053] (Number Average Molecular Weight (Mn), Weight Average Molecular Weight (Mw), and Molecular Weight Distribution (Mw / Mn)) The Mn, Mw, and Mw / Mn of polysiloxane and silicone polyether polyol were measured by the method described below (GPC analysis). Analysis was carried out using a gel permeation chromatography (GPC) system (Tosoh Corporation product name HLC-8320) and an RI detector. Two TSK-GEL Super HZ4000 (4.6 mm x 150 mm) columns and two Super HZ2500 (4.6 mm x 150 mm) columns were connected in series in that order. Tetrahydrofuran (THF) was used as the eluent at a flow rate of 0.35 ml / min, the column temperature was set to 40°C, and Mn and Mw were measured by conversion using a calibration curve prepared using a polystyrene standard sample (Agilent Technologies, product name: Easical PS-2, molecular weight range: 580 to 400,000), and Mw / Mn was calculated.

[0054] (Ratio of Low Molecular Weight Components in Silicone Polyether Polyol) The ratio of the area of ​​the "peaks of silicone polyether polyol with a molecular weight of 750 or less" to the area of ​​"all peaks of silicone polyether polyol" was calculated to measure the ratio of the area of ​​the low molecular weight components in the silicone polyether polyol. The detailed method for calculating the area of ​​the low molecular weight components in the silicone polyether polyol was performed by the GPC analysis described above, and the chart obtained was used as described below in (1) to (4). (1) The polyether polyol to be tested was dissolved in THF for GPC to a concentration of 0.5% by mass, and then filtered through a syringe filter with a pore size of 0.45 μm to prepare a sample. This was analyzed under the HPLC conditions described above to obtain a chromatogram with retention time on the X-axis and signal intensity on the Y-axis. (2) A calibration curve showing the relationship between molecular weight and retention time was created using a polystyrene standard sample (Agilent Technologies product name Polystyrene Low EasyVials, molecular weight range 162-45120). (3) Using the calibration curve created in (2), the retention time X1 corresponding to the peak top molecular weight (also referred to as "Mp") of 750, calculated from the apex of the peak in the molecular weight distribution, and the retention time X2 corresponding to the Mp of 162 were determined. (4) The area enclosed by the chromatogram, the baseline, the line X = X1, and the line X = X2 was electronically integrated to determine the area. In this case, if there was a peak detected in the blank, such as the area due to a stabilizer contained in THF, the area of ​​that peak was excluded.

[0055] [Production of Silicone Polyether Polyol] The production method of the silicone polyether polyol for each example will be described. Examples 1 to 13 are working examples, and Examples 14 to 21 are comparative examples. The products obtained in each example showed a single peak in the chart obtained by GPC analysis, which was different from that of the raw materials.

[0056] Example 1 900 g of the initiator (polysiloxane) α-butyl-ω-{3-[2,2-bis(hydroxymethyl)butoxy]propyl}polydimethylsiloxane (product name: Silaplane (registered trademark; the same applies hereinafter, omitted) FM-DA11, manufactured by JNC Corporation, hydroxyl value 93.1 mgKOH / g) and 0.1 g of TBA-DMC catalyst were placed in an autoclave, and the autoclave was heated to an internal temperature of 130°C under a nitrogen atmosphere, and 450 g of PO was introduced while the internal temperature did not exceed 140°C to allow the reaction. After the introduction of PO was complete, the mixture was stirred for an additional hour at 130°C, and then the unreacted materials were distilled off under reduced pressure to obtain a silicone polyether polyol as a colorless, transparent, oily product.

[0057] Example 2 The same procedure as in Example 1 was carried out, except that the amount of PO was changed to 900 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0058] Example 3 The same procedure as in Example 1 was carried out, except that the amount of PO was changed to 1800 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0059] Example 4 The same procedure as in Example 1 was carried out, except that the amount of PO was changed to 2700 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0060] Example 5 The same procedure as in Example 1 was carried out, except that the amount of PO was changed to 3600 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0061] Example 6 The same procedure as in Example 1 was carried out, except that the initiator was changed to 1,703 g of a diol-modified organosiloxane (product name: X-22-176DX, manufactured by Shin-Etsu Chemical Co., Ltd., hydroxyl value 35.0 mgKOH / g) and the amount of PO was changed to 1,597 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0062] Example 7 The same procedure as in Example 1 was carried out, except that the initiator was changed to 754 g of α-butyl-ω-{3-[2,2-bis(hydroxymethyl)butoxy]propyl}polydimethylsiloxane (product name: Silaplane FM-DA21, manufactured by JNC Corporation, hydroxyl value 23.4 mgKOH / g) and the amount of PO was changed to 472 g, resulting in a silicone polyether polyol as a slightly cloudy oily product.

[0063] Example 8 The same procedure as in Example 1 was carried out, except that the initiator was changed to 968 g of X-22-176DX and the amount of PO was changed to 302 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0064] Example 9 The same procedure as in Example 1 was carried out, except that the initiator was changed to 754 g of Silaplane FM-DA21 and the amount of PO was changed to 151 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0065] Example 10 The same procedure as in Example 1 was carried out, except that the initiator was changed to 721 g of α-butyl-ω-{3-[2,2-bis(hydroxymethyl)butoxy]propyl}polydimethylsiloxane (product name: Silaplane FM-DA26, manufactured by JNC Corporation, hydroxyl value 8.6 mgKOH / g) (polysiloxane) and the amount of PO was changed to 329 g, resulting in a silicone polyether polyol in the form of a slightly cloudy oily product.

[0066] Example 11 The same procedure as in Example 10 was carried out, except that the amount of PO was changed to 329 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0067] Example 12 The same procedure as in Example 1 was carried out, except that the initiator was changed to 1,400 g (polysiloxane) of diol-modified organosiloxane (product name: X-22-176GX-A, manufactured by Shin-Etsu Chemical Co., Ltd., hydroxyl value 35 mgKOH / g) and the amount of PO was changed to 500 g, and a silicone polyether polyol was obtained as a slightly cloudy oily product.

[0068] Example 13 The same procedure as in Example 12 was carried out, except that the amount of PO was changed to 1400 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0069] Example 14 The same procedure as in Example 1 was carried out, except that the initiator was changed to 696 g of a carbinol-modified organopolysiloxane (product name: KF-6002, manufactured by Shin-Etsu Chemical Co., Ltd., hydroxyl value 35.0 mgKOH / g) and the amount of PO was changed to 1,304 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0070] Example 15 The same procedure as in Example 1 was carried out, except that the initiator was changed to 900 g of diol-modified organosiloxane (product name: X-22-176ASX, manufactured by Shin-Etsu Chemical Co., Ltd., molecular weight calculated as hydroxyl value: approximately 1,000) and the amount of PO was changed to 900 g, yielding a silicone polyether polyol as a slightly cloudy oily product.

[0071] Example 16 The same procedure as in Example 15 was carried out, except that the amount of PO was changed to 1800 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0072] Example 17 The same procedure as in Example 15 was carried out, except that the amount of PO was changed to 2700 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0073] Example 18 The same procedure as in Example 15 was carried out, except that the amount of PO was changed to 3600 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0074] Example 19 The same procedure as in Example 1 was carried out, except that the initiator was changed to 1906 g of a mixture of decamethylcyclopentasiloxane and octamethylcyclotetrasiloxane (product name: DOWSIL (registered trademark; the same applies hereinafter; description omitted) SF 8427 Fluid, manufactured by Dow Chemical Japan Ltd.: hydroxyl value-based molecular weight: 2400) and the amount of PO was changed to 794 g, and a silicone polyether polyol was obtained as a slightly cloudy oily product.

[0075] Example 20 The same procedure as in Example 1 was carried out, except that the initiator was changed to 1,473 g of DOWSIL SF 8427 Fluid and the amount of PO was changed to 1,227 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0076] Example 21 The same procedure as in Example 1 was carried out, except that the initiator was changed to 1013 g of DOWSIL SF 8427 Fluid and the amount of PO was changed to 1688 g, to obtain a silicone polyether polyol as a slightly cloudy oily product.

[0077] [Evaluation] The silicone polyether polyol obtained in each example was evaluated as follows. (Measurement of moisture content after one day) The moisture content of the silicone polyether polyol in each example immediately after production was 200 ppm by mass or less. 30 g of silicone polyether polyol was placed in a 50 mL glass vial (inner diameter of mouth approximately 20 mm) and left uncapped in an atmosphere at a temperature of 25°C and a relative humidity of 40% for one day (24 hours), after which the moisture content of the silicone polyether polyol was measured. If the moisture content after one day was 6000 ppm by mass or less, it can be said that the silicone polyether polyol is unlikely to contain moisture. The moisture content was measured by coulometric titration using a Karl Fischer moisture analyzer CA-07 manufactured by Mitsubishi Analytic Co., Ltd.

[0078] (Measurement of upper layer moisture content after saturated saline treatment) The silicone polyether polyol obtained in each example, which had a moisture content of 200 mass ppm or less, and saturated saline were mixed by stirring at a volume ratio of 1:1, and then left to stand for 10 minutes to cause phase separation, and the upper layer moisture content was measured. The moisture content was measured in the same manner as above. If the upper layer moisture content after saturated saline treatment was 6000 mass ppm or less, it can be said that the product is unlikely to absorb moisture even when contacted with or mixed with water. On the other hand, if there is no phase separation and the upper layer moisture content is more than 6000 mass ppm, it is determined that the product is likely to absorb moisture when contacted with or mixed with water.

[0079] (Presence or Absence of Phase Separation After 2 Days) 30 g of the silicone polyether polyol obtained in each example was placed in a 50 mL glass vial (inner mouth diameter of approximately 20 mm), and left to stand without a lid in an atmosphere at a temperature of 25°C and a relative humidity of 40% for 2 days (48 hours), after which it was confirmed whether or not phase separation had occurred.

[0080] The measurement and evaluation results for each example are shown in Tables 1 and 2. Note that items marked with "-" in the tables have not been measured or evaluated.

[0081]

[0082]

[0083] As shown in Table 1, in Examples 1 to 13, in which a polysiloxane having an Mw / Mn of 1.50 or less and having OH groups at its terminals was used as the initiator, the moisture content after one day was 6,000 ppm by mass or less, indicating that a silicone polyether polyol that is less likely to absorb moisture was obtained. This is thought to be because the addition of alkylene oxide to a polysiloxane with a narrow molecular weight distribution made it possible to reduce the content of low-molecular-weight components that are relatively more likely to absorb moisture. On the other hand, as shown in Table 2, in Examples 14 to 21, in which the Mw / Mn of the polysiloxane initiator was greater than 1.50, the moisture content after one day exceeded 6,000 ppm by mass, indicating that a silicone polyether polyol that is less likely to absorb moisture was not obtained.

[0084] Furthermore, the silicone polyether polyols of Examples 1 to 13 had upper layer water contents of 6000 ppm by mass or less after saturated saline treatment, whereas the upper layer water contents of Examples 14 to 18 exceeded 6000 ppm by mass, and no phase separation occurred in Examples 19 to 21.

[0085] Furthermore, the silicone polyether polyols of Examples 1 to 9 did not undergo phase separation even after 2 days.

Claims

1. A method for producing a silicone polyether polyol, comprising reacting an initiator, which is a polysiloxane having a molecular weight distribution of 1.50 or less and which has OH groups at its terminals, with an alkylene oxide in the presence of a catalyst.

2. The method for producing silicone polyether polyols according to claim 1, wherein the catalyst is a composite metal cyanide complex.

3. The method for producing a silicone polyether polyol according to claim 1 or 2, wherein the number average molecular weight of the polysiloxane is 800 or more and 15,000 or less.

4. The method for producing a silicone polyether polyol according to claim 1 or 2, wherein the polysiloxane is a linear molecule having two OH groups at one end.

5. The method for producing a silicone polyether polyol according to claim 1 or 2, wherein the alkylene oxide comprises propylene oxide.

6. The method for producing a silicone polyether polyol according to claim 1 or 2, wherein the number average molecular weight of the silicone polyether polyol is 1,000 or more and 50,000 or less.

7. The method for producing a silicone polyether polyol according to claim 1 or 2, wherein the molecular weight distribution of the silicone polyether polyol is 1.50 or less.

8. A method for producing a silicone polyether polyol according to claim 1 or 2, wherein the silicone polyether polyol has a content of components having a molecular weight of 750 or less of 1.0% or less.

9. A silicone polyether polyol having a number average molecular weight of 1,000 or more and 50,000 or less, wherein the silicone polyether polyol has a moisture content of 200 ppm by mass or less, and after being allowed to stand for one day in an atmosphere having a temperature of 25°C and a relative humidity of 40%, the moisture content is 6,000 ppm by mass or less.

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