TW202321333A - Polyurethane resin composition - Google Patents

Abstract

Provided is a polyurethane resin composition having excellent resistance to wet heat. A polyurethane resin composition according to one embodiment contains a hydroxyl group-containing compound (A) and an isocyanate group-containing compound (B). The hydroxyl group-containing compound (A) includes a polybutadiene polyol (A1) and a butylene oxide-based polyol (A2) in which 50 mol% or more of alkylene oxide units are butylene oxide units. The number average molecular weight of the butylene oxide-based polyol (A2) is 400-3000 inclusive.

Description

Polyurethane resin composition

Embodiments of the present invention relate to a polyurethane resin composition.

Previously, for example, in order to protect electronic circuit boards or electronic parts from external factors, it is known to use a polyurethane resin composition for sealing, and to use polybutadiene polyol as the polyurethane resin Composition of polyols.

For example, Patent Document 1 discloses a polyurethane resin composition containing a hydroxyl-containing compound, an isocyanate group-containing compound, a metal hydroxide, and a plasticizer. The polyurethane In the resin composition, the hydroxyl group-containing compound includes polybutadiene polyol and castor oil-based polyol, and the metal hydroxide is aluminum hydroxide and/or magnesium hydroxide. [Prior art literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2016-20439

[Problem to be Solved by the Invention]

In electrical and electronic parts, they are used under heat and humidity for a long period of time due to their long life, so excellent heat and humidity resistance is required. For example, polyurethane resin compositions that can be used as sealants for electrical insulation are also expected to further Improve heat and humidity resistance.

An object of an embodiment of the present invention is to provide a polyurethane resin composition excellent in heat-and-moisture resistance. [Means to solve the problem]

The present invention includes the embodiments shown below. [1] A polyurethane resin composition comprising a hydroxyl group-containing compound (A) and an isocyanate group-containing compound (B). In the polyurethane resin composition, the hydroxyl group-containing The compound (A) contains a polybutadiene polyol (A1) and a butylene oxide-based polyol (A2) in which 50 mole percent or more of the alkylene oxide units are butylene oxide units, and the butylene oxide The number average molecular weight of the polyol (A2) is 400 or more and 3000 or less. [2] The polyurethane resin composition according to [1], wherein the content of the butylene oxide-based polyol (A2) in 100% by mass of the hydroxyl group-containing compound (A) is 10 mass % or more and 80 mass % or less. [3] The polyurethane resin composition according to [1] or [2], wherein the number average molecular weight of the butylene oxide-based polyol (A2) is 600 to 1600, and the The content of the butylene oxide-based polyol (A2) in 100% by mass of the hydroxyl group-containing compound (A) is 20% by mass or more and 60% by mass or less. [4] The polyurethane resin composition according to any one of [1] to [3], wherein the isocyanate group-containing compound (B) includes an isocyanurate modifier. [5] The polyurethane resin composition according to any one of [1] to [4], which is a two-component type comprising a first liquid and a second liquid, wherein the first liquid contains the In the hydroxyl group-containing compound (A), the second solution contains the isocyanate group-containing compound (B). [6] The polyurethane resin composition according to any one of [1] to [5], which can be used as a sealant for electrical insulation. [Effect of the invention]

According to embodiment of this invention, the polyurethane resin composition excellent in heat-and-moisture resistance can be provided.

The polyurethane resin composition of the present embodiment contains a hydroxyl group-containing compound (A) and an isocyanate group-containing compound (B).

[Hydroxyl-containing compound (A)] As the hydroxyl group-containing compound (A), a polyol compound having two or more hydroxyl groups in one molecule can be used. In this embodiment, the hydroxyl group-containing compound (A) includes polybutadiene polyol (A1) and ring Oxybutane-based polyol (A2).

The polybutadiene polyol (A1) is not particularly limited, but preferably has a polybutadiene structure of 1,4-bond type, 1,2-bond type, or a mixture of these in the molecule and at least Polybutadiene polyol with two hydroxyl groups. More preferably, it is a polybutadiene polyol having hydroxyl groups at both ends of the polybutadiene structure. The polybutadiene polyol (A1) may be a hydrogenated polybutadiene polyol in which a part or all of the unsaturated double bonds have been hydrogenated, and unhydrogenated polybutadiene polyols and hydrogenated ones may be used in combination. In addition, two or more polybutadiene polyols having different molecular weights or functional group numbers may be used in combination.

The molecular weight of the polybutadiene polyol (A1) is not particularly limited. For example, the number average molecular weight (Mn) may be 600-15000, 800-9000, 1000-7000, or 1300-5000. It can also be 1400-3000.

The number of functional groups of the polybutadiene polyol (A1) is not particularly limited, and may be, for example, 2.0 to 4.0, or 2.0 to 2.5.

The hydroxyl value of polybutadiene polyol (A1) is not particularly limited, for example, it may be 10 mgKOH/g to 200 mgKOH/g, 15 mgKOH/g to 150 mgKOH/g, or 20 mgKOH/g ~120 mgKOH/g, or 25 mgKOH/g~100 mgKOH/g, or 40 mgKOH/g~90 mgKOH/g.

In this specification, the number average molecular weight (Mn) of polybutadiene polyol (A1) is measured by Gel Permeation Chromatography (GPC (Gel Permeation Chromatography) method) using standard polystyrene calibration The value calculated from the curve. GPC conditions are, for example, column: "TSKgel GMHHR-H" manufactured by Tosoh Co., Ltd., solvent: tetrahydrofuran (THF), flow rate: 0.6 mL/min, and measurement temperature: 40°C. The hydroxyl value of polybutadiene polyol (A1) is the value measured according to the method A of Japanese Industrial Standards (JIS) K1557-1:2007. base) mg of potassium hydroxide (KOH) reacted with acetylated acetic acid. The number of functional groups of the polybutadiene polyol (A1) is a value calculated by the following formula. Functional group number={(hydroxyl value)×(Mn)}/(56.1×1000)

The content of the polybutadiene polyol (A1) is not particularly limited, but is preferably from 20% by mass to 90% by mass, more preferably from 40% by mass to 80% by mass, based on 100% by mass of the hydroxyl group-containing compound (A). %, and more preferably 50% by mass to 80% by mass.

The butylene oxide polyol (A2) is a polyol in which 50 mol% or more of the alkylene oxide units are butylene oxide units. More specifically, the butylene oxide polyol (A2) is a polyalkylene glycol in which more than 50 mol% of all the alkylene oxides used to form the polyol is butylene oxide, and it is a polybutylene glycol in a broad sense. alcohol. As the hydroxyl group-containing compound (A), by using the butylene oxide polyol (A2) together with the polybutadiene polyol (A1), the viscosity of the polyurethane resin composition can be improved. Heat and humidity resistance. Moreover, compared with the case of using a castor oil type polyol, the mixing viscosity at the time of manufacture of a polyurethane resin composition can be reduced, and workability can be improved.

In the butylene oxide polyol (A2), from the viewpoint of heat and humidity resistance and compatibility with the polybutadiene polyol (A1), the butylene oxide unit relative to all the alkylene oxide units The amount is preferably at least 60 mol %, more preferably at least 70 mol %, may be at least 80 mol %, may be at least 90 mol %, or may be at least 100 mol %. When it has an alkylene oxide unit other than a butylene oxide unit, it does not specifically limit as this other alkylene oxide unit, For example, an ethylene oxide unit and/or a propylene oxide unit is mentioned.

In a preferred embodiment, the butylene oxide polyol (A2) may be polytetramethylene glycol containing butylene oxide units at 100 mol % of the alkylene oxide units.

In this embodiment, as a butylene oxide type polyol (A2), what has a number average molecular weight (Mn) of 400-3000 is used. When the number average molecular weight of the butylene oxide polyol (A2) is 400 or more, the compatibility with the polybutadiene polyol (A1) can be improved. Moreover, the curability of a polyurethane resin composition can be improved by being 3000 or less. The number average molecular weight of the butylene oxide polyol (A2) is preferably at least 600, more preferably at least 800. The number average molecular weight is preferably 2,000 or less, more preferably 1,600 or less, and may be 1,300 or less.

The hydroxyl value of the butylene oxide polyol (A2) is not particularly limited, for example, it may be 37 mgKOH/g to 500 mgKOH/g, or 50 mgKOH/g to 300 mgKOH/g, or 60 mgKOH/g. g ~ 200 mgKOH/g.

In this specification, the number average molecular weight (Mn) of a butylene oxide type polyol (A2) is the value converted from the hydroxyl value and the number of functional groups according to the following formula. Number average molecular weight=56.1×1000×functional group number/hydroxyl value The hydroxyl value of the butylene oxide polyol (A2) is a value (mgKOH/g) measured in accordance with A method of JIS K1557-1:2007. The number of functional groups of the butylene oxide polyol (A2) is determined from the number of active hydrogens in the active hydrogen atom-containing compound as an initiator as described below.

The structure of the butylene oxide polyol (A2) is not particularly limited. For example, a compound having 2 to 8 active hydrogen atoms may be used as an initiator and an alkylene oxide containing butylene oxide may be used therein. A structure formed by addition polymerization. As butylene oxide, 1,2-butylene oxide and/or 2,3-butylene oxide can be used, preferably 1,2-butylene oxide.

As the initiator, for example, when a compound (diol) having two active hydrogen atoms such as ethylene glycol or propylene glycol is used, a difunctional butylene oxide-based polyol (A2) can be obtained. In addition, when a compound (triol) having three active hydrogen atoms such as glycerin or trimethylolpropane is used as an initiator, a trifunctional butylene oxide polyol (A2) can be obtained. It is considered that trifunctional curing is faster than difunctional curing, so when faster curing is required, trifunctional butylene oxide polyol (A2) can also be used. The number of functional groups of the butylene oxide polyol (A2) is not particularly limited, and may be 2-8 or 2-4. Preferably, the butylene oxide-based polyol (A2) is difunctional or trifunctional, and a difunctional polyol and a trifunctional polyol may be used in combination.

In addition, as the form of the addition polymerization, when other alkylene oxides are copolymerized with butylene oxide, random copolymerization or block copolymerization may be used. In one embodiment, a terminal epoxy compound having a structure in which ethylene oxide is added to the end of the polybutylene oxide chain after addition polymerization of butylene oxide in the initiator can also be used. Addition of ethane to polytetramethylene glycol. By adding ethylene oxide to the terminal, the curability can be improved.

In addition, as the butylene oxide-based polyol (A2), any polyol having the above structure can be used, and two or more polyols having different number average molecular weights, structures, and the like can also be used in combination.

The content of the butylene oxide polyol (A2) is not particularly limited, but is preferably 10% by mass to 80% by mass relative to 100% by mass of the hydroxyl group-containing compound (A). When content of a butylene oxide type polyol (A2) is 10 mass % or more, the mixing viscosity at the time of manufacture of a polyurethane resin composition can be reduced. Moreover, curability can be improved by making this content into 80 mass % or less. The content of the butylene oxide polyol (A2) is more preferably from 20% by mass to 60% by mass, and more preferably from 20% by mass to 50% by mass.

The mass ratio of polybutadiene polyol (A1) to butylene oxide polyol (A2) is not particularly limited, but (A2)/(A1) is preferably 0.1 to 3.5, more preferably 0.2 to 1.0 .

In the present embodiment, the hydroxyl-containing compound (A) may contain only polybutadiene polyol (A1) and butylene oxide-based polyol (A2), or may contain other hydroxyl-containing compounds. The total amount (A1+A2) of the polybutadiene polyol (A1) and the butylene oxide polyol (A2) relative to 100% by mass of the hydroxyl group-containing compound (A) is not particularly limited, and preferably It is 70 mass % or more, More preferably, it is 80 mass % or more, More preferably, it is 90 mass % or more, It may be 100 mass %.

Various polyhydric alcohols can be used as the other hydroxyl group-containing compound, and are not particularly limited. Examples thereof include castor oil, castor oil fatty acid, and castor oil-based polyols produced using hydrogenated castor oil or hydrogenated castor oil fatty acid obtained by adding hydrogen to these. In addition, other polyester polyols, polyether polyols, polycarbonate polyols, dimer acid polyols, polycaprolactone polyols, acrylic polyols, polyisoprene polyols, and the like are exemplified. Furthermore, low-molecular-weight polyols generally used as crosslinking agents may also be used. Specifically, N,N-bis(2-hydroxypropyl)aniline, hydroquinone-bis(β-hydroxyethyl) Aromatic alcohols such as resorcinol-bis(β-hydroxyethyl)ether, ethylene glycol, 1,4-butanediol, octanediol, trimethylolpropane, triisopropanolamine and other aliphatic alcohols.

[Isocyanate group-containing compound (B)] As the isocyanate group-containing compound (B), various polyisocyanate compounds having two or more isocyanate groups in one molecule can be used. Examples of the isocyanate group-containing compound (B) include aliphatic polyisocyanate compounds (B1), alicyclic polyisocyanate compounds (B2), aromatic polyisocyanate compounds (B3), and modified forms thereof and As the polykaryon, any one type may be used, or two or more types may be used in combination.

Examples of the aliphatic polyisocyanate compound (B1) include tetramethylene diisocyanate, dodecamethylene diisocyanate, hexamethylene diisocyanate (Hexamethylene Diisocyanate, HDI), 2,2,4-trimethyl Hexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methylpentane -1,5-diisocyanate, etc.

Examples of the alicyclic polyisocyanate compound (B2) include: isophorone diisocyanate (Isophorone Diisocyanate, IPDI), hydrogenated xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4 - Cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis(methylisocyanate)cyclohexane, and the like.

Examples of the aromatic polyisocyanate compound (B3) include: toluene diisocyanate (TDI (Tolylene Diisocyanate), such as 2,4-TDI, 2,6-TDI), diphenylmethane diisocyanate (MDI (Diphenylmethane Diisocyanate) , such as 2,2'-MDI, 2,4'-MDI, 4,4'-MDI), 4,4'-dibenzyl diisocyanate, 1,5-naphthyl diisocyanate, xylylene diisocyanate (Xylylene Diisocyanate, XDI), 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, etc.

Modified products of these polyisocyanate compounds (B1) to (B3) include, for example, isocyanurate modified products, allophanate modified products, biuret modified products, and adduct modified products. Plastids, modified carbodiimides, etc.

In one embodiment, the isocyanate group-containing compound (B) preferably includes an isocyanurate modifier. By using the isocyanurate modifier, the miscibility with the hydroxyl group-containing compound (A) is excellent, and the uniformity of hardness after curing of the polyurethane resin composition can be improved. Examples of the modified isocyanurate include: a modified isocyanurate of an aliphatic polyisocyanate compound (B1), a modified isocyanurate of an alicyclic polyisocyanate compound (B2), Isocyanurate modified form of aromatic polyisocyanate compound (B3). It is preferably an isocyanurate-modified body of the aliphatic polyisocyanate compound (B1), more preferably HDI isocyanurate.

In another embodiment, the isocyanate group-containing compound (B) preferably includes HDI. As the isocyanate group-containing compound (B), HDI and the above-mentioned isocyanurate modifier may be used in combination, or HDI and HDI isocyanurate may be used in combination.

In yet another embodiment, the isocyanate group-containing compound (B) may also contain MDI. MDI may be monomeric (monomeric) MDI or polymeric (polymeric) MDI (crude (crude) MDI). As the isocyanate group-containing compound (B), MDI and the above-mentioned HDI and/or isocyanurate modifier (preferably HDI isocyanurate) may be used in combination.

The content of the isocyanate group-containing compound (B) in the polyurethane resin composition is not particularly limited, for example, it may be 5 to 60 parts by mass with respect to 100 parts by mass of the hydroxyl group-containing compound (A). , may be 8 to 50 parts by mass, may be 10 to 40 parts by mass, or may be 15 to 30 parts by mass.

The ratio of the hydroxyl group-containing compound (A) to the isocyanate group-containing compound (B) is not particularly limited, for example, the ratio of the isocyanate group contained in the isocyanate group-containing compound (B) to the hydroxyl group contained in the hydroxyl group-containing compound (A) The molar ratio NCO/OH (index) may be 0.6-1.5, 0.7-1.3, or 0.8-1.2.

[other ingredients] In the polyurethane resin composition of this embodiment, in addition to the above-mentioned components, for example, a catalyst, an antioxidant, a foam stabilizer, and a diluent may be added as needed within a range that does not impair the purpose of this embodiment. , flame retardants, UV absorbers, colorants, fillers, plasticizers and other additives.

As the catalyst, for example, metal catalysts such as organic tin catalysts, organic lead catalysts, and organic bismuth catalysts, and various urethane polymerization catalysts such as amine catalysts can be used. The content of the catalyst is not particularly limited, and may be, for example, 0.0001% by mass to 0.1% by mass, or 0.001% by mass to 0.01% by mass relative to 100% by mass of the polyurethane resin composition.

[Polyurethane resin composition] The polyurethane resin composition of the present embodiment may also be configured as a two-component polyurethane resin composition including a first liquid and a second liquid, the first liquid containing a hydroxyl group-containing compound ( A), the second liquid contains an isocyanate group-containing compound (B). The two-component polyurethane resin composition may further include a third solution containing the other components as well as the first solution and the second solution.

The two-liquid type polyurethane resin composition can be produced by separately preparing the first liquid and the second liquid, that is, the first liquid and the second liquid can be filled in different containers, respectively. The first liquid and the second liquid filled in different containers can also be mixed at the time of use to react the hydroxyl group-containing compound (A) and the isocyanate group-containing compound (B) to form a polyurethane resin and harden. At this time, it can also be cured by heating. The polyurethane resin composition of this embodiment may be a composition obtained by mixing the first liquid and the second liquid, may be liquid before hardening, or may be a composition after hardening.

The first solution may contain only the hydroxyl-containing compound (A). In addition, in addition to the hydroxyl-containing compound (A), for example, catalysts, antioxidants, foam stabilizers, diluents, flame retardants, Various additives such as UV absorbers, colorants, fillers, plasticizers, etc. Preferably, the first liquid contains the hydroxyl-containing compound (A) and a catalyst.

The second liquid may contain only the isocyanate group-containing compound (B). In addition, in addition to the isocyanate group-containing compound (B), other ingredients such as antioxidants, foam stabilizers, diluents, flame retardants, ultraviolet rays, etc. Various additives such as absorbents, colorants, fillers, plasticizers, etc.

[Use of polyurethane resin composition] The use of the polyurethane resin composition of this embodiment is not particularly limited, but it is preferably used as a sealant for electrical insulation in electric and electronic parts. The electrical and electronic components are not particularly limited, and examples thereof include transformers such as transformer coils, choke coils, and reactance coils, device control boards, sensors, and wireless communication components.

Electrical and electronic parts resin-sealed using the polyurethane resin composition of this embodiment can be used, for example, in electric washing machines, toilets, water heaters, water purifiers, bathrooms, dishwashers, solar panels, and electric tools. , cars, motorcycles, etc. [Example]

Hereinafter, the polyurethane resin composition will be described in detail based on Examples and Comparative Examples, but the present invention is not limited thereto.

Details of each component used in Examples and Comparative Examples are shown below.

[Hydroxyl-containing compound (A)] ・Polybutadiene polyol 1: number average molecular weight 2800, hydroxyl value 47 mgKOH/g, functional group number 2.3, product name: Poly bd R-45HTLO, manufactured by Cray Valley ・Polybutadiene polyol 2: The number average molecular weight is 1600, the hydroxyl value is 80 mgKOH/g, the number of functional groups is 2.3, and it is prepared according to the following production method

150 parts by mass of 1,3-butadiene, 105 parts by mass of an azeotrope containing 88 mass % of isopropanol and 12 mass % of water, and 30 parts by mass of 60% hydrogen peroxide aqueous solution. The content of the reactor was heated to 120° C. while stirring continuously, and was kept at 120° C. to 130° C. while stirring, and a polymerization reaction was performed for 2 hours. After the specified time is completed, the contents of the reactor are cooled, the reaction product is taken out from the reactor, unreacted monomers are removed from the reaction product, and the product is washed with water to remove residual isopropanol and Unreacted hydrogen peroxide. The resultant was vacuum-dried to obtain a polybutadiene polyol having a viscosity of 5000 mPa·s at 25°C.

・Butylene Oxide (BO)-based polyol 1: polytetramethylene glycol (number average molecular weight: 3,000 , number of functional groups 2, the amount of butylene oxide units in all alkylene oxide units 100 mol%)

Synthesis Example 1: 0.55 parts by mass of 48% KOH and 10.8 parts by mass of 1,2-epoxybutane (BO) were put into 2.53 parts by mass of propylene glycol in a stainless steel autoclave, and the inside of the autoclave was reduced after nitrogen replacement. pressure, heating. Then, after the BO introduction reaction was carried out at 120°C±5°C and the highest pressure of 0.2 MPa, the BO aging reaction was carried out at 120±5°C for 240 minutes. Then, after cooling to 80°C, the pressure was reduced to 10 mmHg or less at 90°C to 110°C. Then, 86.67 parts by mass of BO was added, and BO introduction reaction was performed at 120°C±5°C and a maximum pressure of 0.4 MPa, followed by BO aging reaction at 120±5°C for 360 minutes. After cooling, the pressure was reduced to 20 mmHg (2.7 kPa) at 100±5° C., followed by purification and filtration to obtain difunctional polytetramethylene glycol.

BO-based polyol 2: The amount of BO added after the first-stage BO aging reaction in Synthesis Example 1 was set to 40 parts by mass, and in the same manner as Synthesis Example 1, propylene glycol was used as the starting material. Polytetramethylene glycol (number average molecular weight 1600, number of functional groups 2, amount of butylene oxide unit in all alkylene oxide units 100 mol%) obtained by addition polymerization of butylene oxide as an initiator

BO-based polyol 3: The amount of BO added after the first-stage BO aging reaction in Synthesis Example 1 was set to 13.3 parts by mass, and in the same manner as Synthesis Example 1, propylene glycol was used as the starting material. Polytetramethylene glycol (number average molecular weight 800, number of functional groups 2, amount of butylene oxide unit in all alkylene oxide units 100 mol%) obtained by addition polymerization of butylene oxide as starter

・BO-based polyol 4: polytetramethylene glycol (number average molecular weight 400, number of functional groups 2, all alkylene oxides) The amount of butylene oxide unit in the unit is 100 mole%)

Synthesis Example 2: 0.83 parts by mass of 48% KOH and 81 parts by mass of 1,2-butylene oxide (BO) were added to 19 parts by mass of propylene glycol in a stainless steel autoclave, and after nitrogen replacement, the interior of the autoclave was reduced. pressure, heating. Then, after the BO introduction reaction was carried out at 120°C±5°C and the highest pressure of 0.2 MPa, the BO aging reaction was carried out at 120±5°C for 240 minutes. After de-BO cooling, the pressure was reduced to 20 mmHg (2.7 kPa) at 100±5°C, followed by purification and filtration to obtain difunctional polytetramethylene glycol.

BO-based polyol 5: Terminal ethylene oxide (Ethylene oxide) obtained by addition-polymerizing butylene oxide with propylene glycol as an initiator and adding ethylene oxide to the end according to Synthesis Example 3 below. Oxide, EO) added polytetramethylene glycol (the number average molecular weight is 1250, the number of functional groups is 2, the amount of butylene oxide units in all alkylene oxide units is 57 mol%, and the amount of ethylene oxide units is 43 mol%. )

Synthesis Example 3: Add 0.55 parts by mass of 48% KOH and 25.9 parts by mass of 1,2-butylene oxide (BO) to 6.08 parts by mass of propylene glycol in a stainless steel autoclave. pressure, heating. Then, after the BO introduction reaction was carried out at 120°C±5°C and the highest pressure of 0.2 MPa, the BO aging reaction was carried out at 120±5°C for 240 minutes. Then, after cooling to 80°C, it was extracted, and the pressure was reduced to 10 mmHg or less at 90°C to 110°C. Then, 38.0 parts by mass of BO was added, BO introduction reaction was performed at 120°C±5°C and a maximum pressure of 0.4 MPa, and then BO aging reaction was performed at 120±5°C for 360 minutes. Then, 30.0 parts by mass of ethylene oxide (EO) was added, EO introduction reaction was performed at 120°C±5°C and a maximum pressure of 0.4 MPa, and then EO aging reaction was performed at 120±5°C for 360 minutes. After de-EO cooling, the pressure was reduced to 20 mmHg (2.7 kPa) at 100±5°C, followed by purification and filtration to obtain EO terminal added polytetramethylene glycol.

BO-based polyol 6: polytetramethylene glycol (number average molecular weight 1100, functional group number 3, all alkylene oxides The amount of butylene oxide unit in the unit is 100 mole%)

Synthesis Example 4: 0.5 parts by mass of 48% KOH and 28.1 parts by mass of 1,2-epoxybutane (BO) were put into 8.37 parts by mass of glycerin in a stainless steel autoclave, and the interior of the autoclave was reduced after nitrogen replacement. pressure, heating. Then, after the BO introduction reaction was carried out at 120°C±5°C and the highest pressure of 0.2 MPa, the BO aging reaction was carried out at 120±5°C for 240 minutes. Then, after cooling to 80°C, the pressure was reduced to 10 mmHg or less at 90°C to 110°C. Then, 63.62 parts by mass of BO was added, BO introduction reaction was performed at 120°C±5°C and a maximum pressure of 0.4 MPa, and then BO aging reaction was performed at 120±5°C for 360 minutes. After cooling, the pressure was reduced to 20 mmHg (2.7 kPa) at 100±5° C., followed by purification and filtration to obtain trifunctional polytetramethylene glycol.

BO-based polyol 7: Terminal EO-added polybutylene obtained by addition-polymerizing butylene oxide with glycerin as an initiator and adding ethylene oxide to the terminal according to Synthesis Example 5 below. Alcohol (number average molecular weight 1120, functional group number 3, the amount of butylene oxide units in all alkylene oxide units is 84 mol%, the amount of ethylene oxide units is 16 mol%)

Synthesis Example 5: In the above Synthesis Example 4, 55.24 parts by mass of BO and 10.2 parts by mass of ethylene oxide (EO) were added to the BO aging reaction in the second stage, and at 120°C±5°C and the highest pressure After the EO introduction reaction was carried out at 0.4 MPa, the EO aging reaction was carried out at 120±5°C for 360 minutes. After de-EO cooling, the pressure was reduced to 20 mmHg (2.7 kPa) at 100±5°C, followed by purification and filtration to obtain trifunctional EO terminal added polytetramethylene glycol.

Propylene oxide (PO)-based polyol 1: polypropylene glycol with a number average molecular weight of 700 and a functional group of 2, product name: Hiflex D-700, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd. ・PO-based polyol 2: Polypropylene glycol with a number average molecular weight of 1000 and a functional group of 2, product name: Hiflex D-1000, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd. · PO-based polyol 3: Polyoxyethylene polyoxypropylene glycol with a number average molecular weight of 1300 and a functional base of 2, product name: EPAN 410, manufactured by Daiichi Industrial Pharmaceutical Co., Ltd. · PO-based polyol 4: Polypropylene glycol with a number average molecular weight of 1000 and a functional base of 3, product name: X-2116, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd. · PO-based polyol 5: Polypropylene glycol with a number average molecular weight of 3000 and a functional group of 3, product name: Hiflex G-3000, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd. ・Castor oil-based polyol: number average molecular weight 938, functional base 2.7, product name: castor oil D, manufactured by Ito Oil Co., Ltd.

[catalyst] Catalyst: Dioctyltin, product name: Neostann U-810, manufactured by Nitto Chemical Co., Ltd.

[Isocyanate group-containing compound (B)] ・Polyisocyanate 1: HDI isocyanurate, product name: Duranate TPA-100, manufactured by Asahi Kasei Co., Ltd. ・Polyisocyanate 2: HDI, product name: Duranate (Duranate) D-201, manufactured by Asahi Kasei Co., Ltd. ・Polyisocyanate 3: Crude MDI, product name: Lupranate M5S, manufactured by BASF INOAC Polyurethane Co., Ltd.

[Example 1 to Example 10 and Comparative Example 1 to Comparative Example 6] The polyurethane resin composition of each Example and each comparative example was prepared by the preparation (parts by mass) shown in following Table 1 and Table 2. During preparation, a predetermined amount of the first liquid shown in Table 1 and Table 2 was weighed, stirred and mixed while appropriately applying heat to dissolve, and adjusted to 25° C. after mixing. Next, as described in Table 1 and Table 2, the second liquid (isocyanate group-containing compound (B)) adjusted to 25° C. was added to the mixture, stirred and mixed, and defoamed.

Regarding each Example and each Comparative Example, compatibility, curability, durability, volume resistivity, and migration characteristics were measured and evaluated. Measurement and evaluation methods are as follows.

[compatibility] After mixing polybutadiene polyol, which is a hydroxyl-containing compound, with BO-based polyols, PO-based polyols, or castor oil-based polyols, let it stand at room temperature for 7 days. The state of the liquid is evaluated. A: Transparent B: cloudy C: separation

[hardening] The defoamed polyurethane resin composition was poured into a container measuring 5 cm in length x 5 cm in width x 3 cm in height, and placed in a curing oven at 80° C. for 1 hour, then the hardness of the resin was measured. The hardness was measured with a type A durometer according to JIS K6253-3 and a type C hardness tester according to JIS K7312, and evaluated by the following criteria. In addition, curability is an evaluation of whether it hardens rapidly. A: Type A durometer hardness is above 0, B: The hardness of Type A hardness tester is less than 0 (it cannot be measured by Type A hardness tester) and the hardness of Type C hardness is above 0 C: No hardening or liquid

[durability] The defoamed polyurethane resin composition was poured into a mold measuring 5 cm in length x 5 cm in width x 1 cm in height, and cured in a curing oven at 80°C for 48 hours to produce a resin sheet. The resin sheet was treated in a high-temperature and high-humidity tank at a temperature of 121°C, a humidity of 100%, and 2 atm. After 500 hours and 1,000 hours, the hardness was measured by a type A hardness tester in accordance with JIS K6253-3. The change from the initial hardness was confirmed, and the following criteria were used for evaluation. A: The change in hardness after 1000 hours is less than 10% B: The hardness change after 500 hours is less than 10% and the hardness change after 1000 hours is more than 10% C: Change in hardness after 500 hours is 10% or more

[Volume Inherent Resistance] A resin sheet having the same durability as the above was produced, and the resin sheet was processed in a high-temperature and high-humidity tank at a temperature of 121°C, a humidity of 100%, and 2 atm. After 500 hours, 750 hours , After 1000 hours, the volume resistivity was measured according to JIS K6911 (measurement voltage: 500 V), and the following criteria were used for evaluation. A: The volume specific resistance after 1000 hours is 10 ⁹ Ω·cm or more B: The volume specific resistance after 1000 hours is less than 10 ⁹ Ω·cm and the volume specific resistance after 750 hours is 10 ⁹ Ω·cm or more C : The volume specific resistance after 750 hours is less than 10 ⁹ Ω·cm and the volume specific resistance after 500 hours is 10 ⁹ Ω·cm or more

[Migration Features] Arrange the JIS2-type comb-shaped electrode substrate in a glass petri dish, and wire the anode and cathode. The defoamed polyurethane resin composition was cast thereon, and cured in a curing oven at 80° C. for 48 hours to prepare a test piece. This test piece was subjected to a migration test by applying a voltage of 100 V in a humid heat chamber at a temperature of 85°C and a humidity of 85%, and whether or not it was energized before 1000 hours passed was evaluated by the following criteria. The more moisture around the electrode, the more copper ions will dissolve from the anode, move to the cathode, and precipitate on the cathode side. If the precipitated portion grows, insulation failure will result, and eventually the wiring patterns will be short-circuited. This is a test of whether or not the short circuit occurs. A: No power C: Powered on

[Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Blending (parts by mass) first liquid Polybutadiene polyol 1 65 44 62 55.6 64 63.6 60.5 Polybutadiene polyol 2 56 BO series polyol 1 twenty two BO series polyol 2 44 28 BO series polyol 3 twenty one BO series polyol 4 18.5 BO series polyol 5 twenty one BO series polyol 6 21.2 BO series polyol 7 20.2 PO-based polyol 1 PO-based polyol 2 PO-based polyol 3 PO-based polyol 4 PO-based polyol 5 Castor oil based polyols catalyst 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003 second liquid Polyisocyanate 1 13 12 16 17 25.9 15 15.3 19.4 Polyisocyanate 2 Polyisocyanate 3 total 100.003 100.003 100.003 100.003 100.003 100.003 100.003 100.003 NCO/OH (index) 1.1 0.75 0.8 0.95 1.03 0.97 0.76 1.02 BO series in hydroxyl-containing compounds 25 50 33 25 25 25 25 25 Content of polyol (mass%) evaluate Compatibility A A A A B A A A sclerosis B A A A A A A A Durability A A A A A A A A volume intrinsic resistance A A A A A A A A migration characteristics A A A A A A A A

[Table 2] Example 9 Example 10 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative Example 5 Comparative example 6 Blending (parts by mass) first solution Polybutadiene polyol 1 60 64 61 63 66 65 61 Polybutadiene polyol 2 56 BO series polyol 1 BO series polyol 2 20 BO series polyol 3 BO series polyol 4 BO series polyol 5 BO series polyol 6 twenty one BO series polyol 7 PO-based polyol 1 20 PO-based polyol 2 20 PO-based polyol 3 twenty two PO-based polyol 4 19 PO-based polyol 5 twenty two Castor oil based polyols 20 catalyst 0.003 0.0005 0.003 0.003 0.003 0.003 0.003 0.003 second liquid Polyisocyanate 1 19 17 12 25 13 19 Polyisocyanate 2 20 Polyisocyanate 3 15 total 100.003 100.0005 100.003 100.003 100.003 100.003 100.003 100.003 NCO/OH (index) 1 1 0.95 0.98 0.75 1.01 1 1 BO series in hydroxyl-containing compounds 25 25 0 0 0 0 0 0 Content of polyol (mass%) evaluate Compatibility A A B A B A A B sclerosis A A B A A A C C Durability A A A A A A A C volume intrinsic resistance A A C C C C C B migration characteristics A A C C C C C A

The results are shown in Table 1 and Table 2. In Comparative Examples 1 to 5 using PO-based polyol 1 to PO-based polyol 5 as polyols used in combination with polybutadiene polyol, the durability (hardness change) after wet heat treatment was excellent, but After the treatment, the reduction in the volume resistivity is large, and the migration characteristics are also poor, and the heat and humidity resistance is poor.

In Comparative Example 6 using castor oil-based polyol as the polyol used in combination with polybutadiene polyol, the migration characteristics after wet heat treatment were excellent, but the durability (hardness change) after wet heat treatment was poor. Resistance, also found a tendency to decrease. Moreover, when using a castor oil type polyol, sclerosis|curability is also inferior.

On the other hand, in Examples 1 to 10 in which polybutadiene polyol and BO-based polyol were used in combination, the durability (hardness change), volume specific resistance, and migration characteristics after wet heat treatment were excellent. 1 to Comparative Example 6 were excellent in heat-and-moisture resistance.

In addition, various numerical ranges described in the specification can respectively arbitrarily combine their upper limit values and lower limit values, and all combinations thereof are described in the present specification as preferable numerical ranges. In addition, description of the numerical range of "X-Y" means more than X and less than Y.

Some embodiments of the present invention have been described above, but these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments or omissions, substitutions, changes, and the like are included in the scope or spirit of the invention, and are also included in the inventions described in the claims and their equivalent scopes.

none

Claims (6)

A polyurethane resin composition, comprising a hydroxyl-containing compound (A) and an isocyanate group-containing compound (B), in the polyurethane resin composition, The hydroxyl group-containing compound (A) comprises polybutadiene polyol (A1) and butylene oxide polyol (A2) in which more than 50 mol% of alkylene oxide units are butylene oxide units, The number average molecular weight of the said butylene oxide type polyol (A2) is 400-3000. The polyurethane resin composition according to claim 1, wherein the content of the butylene oxide polyol (A2) in 100% by mass of the hydroxyl-containing compound (A) is 10% by mass Above and below 80% by mass. The polyurethane resin composition according to claim 1 or claim 2, wherein the number average molecular weight of the butylene oxide polyol (A2) is not less than 600 and not more than 1600, and the hydroxyl-containing The content of the butylene oxide-based polyol (A2) in 100% by mass of the compound (A) is 20% by mass or more and 60% by mass or less. The polyurethane resin composition according to any one of claim 1 to claim 3, wherein the isocyanate group-containing compound (B) includes an isocyanurate modifier. The polyurethane resin composition as described in any one of claim 1 to claim 4 is a two-component type comprising a first liquid and a second liquid, and the first liquid contains the hydroxyl-containing The compound (A), the second liquid contains the isocyanate group-containing compound (B). The polyurethane resin composition according to any one of claims 1 to 5 can be used as a sealant for electrical insulation.