JP5864008B1 - Polyol composition for production of polyurethane resin composition - Google Patents

Abstract

Disclosed is a polyurethane resin composition in which foaming is further suppressed while containing an inorganic filler. A polyol for producing a polyurethane resin composition comprising a polyol, an inorganic filler, and a catalyst, wherein the water content is adjusted to 0.2% or less by a heating treatment and / or a reduced pressure treatment. A polyurethane resin composition is produced using the composition. [Selection figure] None

Description

  The present invention relates to a polyol composition for producing a polyurethane resin composition, a polyurethane resin composition containing the polyol composition, an electric / electronic component sealed with the resin composition, and the like.

  In recent years, the density and integration of electric and electronic parts have been increased, and the demand for improving the reliability of each part has increased. Under such circumstances, electrical and electronic parts such as printed circuit boards are sealed with resin, resulting in electrical and electronic effects caused by external environmental factors (physical factors such as vibration and dropping; ultraviolet light; chemical factors such as moisture and salt). Attempts have been made to eliminate the effects on parts. For example, a polyurethane-based resin is used as an electrical insulating sealing material for electrical and electronic parts because it has good flexibility, abrasion resistance, low-temperature curability, electrical characteristics, and the like.

  Polyurethane resins are widely used as coating agents, adhesives, and the like in a wide range of fields such as electricity, electronics, automobiles, civil engineering, and architecture in addition to electrical insulating sealing materials.

JP 2010-150474 A Published JP 2010-180384 JP 2000-219806 published Published Japanese Patent Application Laid-Open No. 2005-132093

  When producing a polyurethane-based resin used for electrical and electronic parts, an inorganic filler typified by a metal hydroxide may be blended for the purpose of imparting heat dissipation and flame retardancy. However, in that case, since the blending ratio of the polyol and the polyisocyanate becomes small, it is considered that foaming and poor curing are likely to occur even when a small amount of water is present. In the polyurethane-based resin, foaming leads to a decrease in waterproofness, electrical insulation, and heat dissipation, and is not particularly desirable when used as an electrical insulation sealing material.

  In Patent Document 1, the problem of poor curing is achieved by using a metal hydroxide having specific physical properties, but other inorganic fillers cannot be dealt with. Patent Documents 2 to 4 describe techniques related to dehydration of polyols (Patent Document 2: Dehydrating Agent, Patent Documents 3 and 4: Heating and Decompression), but these include inorganic fillers (particularly metal hydroxide). The above problem due to the blending of the product is not taken into consideration. Further, Patent Documents 1 to 4 do not discuss from the viewpoint of suppressing foaming.

  Therefore, an object of the present invention is to provide a polyurethane resin composition in which foaming is further suppressed while containing an inorganic filler. Furthermore, it is to provide a polyurethane resin composition having excellent thermal conductivity and excellent curing stability (moderate curing rate, hardly causing foaming and poor curing, and little change in curing rate). Is also an issue.

  As a result of intensive studies in view of the above problems, the present inventors contain a polyol, an inorganic filler, and a catalyst, and the water content is adjusted to 0.2% or less by heating treatment and / or decompression treatment. By producing a polyurethane resin composition using a polyol composition for producing a polyurethane resin composition (hereinafter sometimes abbreviated as “the polyol composition of the present invention”), I found that I can achieve. Further research based on this finding has led to the completion of the present invention. That is, the present invention includes the following aspects.

  Item 1. A polyol composition for producing a polyurethane resin composition, comprising a polyol, an inorganic filler and a polymerization catalyst, wherein the water content is adjusted to 0.2% or less by a heating treatment and / or a reduced pressure treatment.

  Item 2. Item 2. The polyol composition according to Item 1, wherein the inorganic filler is a metal hydroxide.

  Item 3. Item 3. The polyol composition according to Item 1 or 2, wherein the content of the inorganic filler is 50 to 85% by mass with respect to 100% by mass of the polyol composition.

  Item 4. Item 4. The polyol composition according to any one of Items 1 to 3, wherein the polyol is a polybutadiene polyol and / or a castor oil-based polyol.

Item 5. (Step a) a step of heating and / or decompressing a composition containing a polyol and an inorganic filler to reduce the water content of the composition;
(Step b) A step of adding a polymerization catalyst to the composition that has undergone step a, and (Step c) The composition that has undergone step b is subjected to a heating treatment and / or a reduced pressure treatment to reduce the water content of the composition. Item 5. The polyol composition according to any one of Items 1 to 4, obtained by a method comprising a step.

Item 6. The temperature condition of the heating treatment in the step a is 40 ° C to 130 ° C,
The temperature condition of the heating treatment in the step c is 40 ° C. to 70 ° C., and the atmospheric pressure condition of the pressure reduction treatment in the steps a and c is 2.7 kPa or less,
Item 6. The polyol composition according to Item 5.

  Item 7. Item 7. The polyol composition according to any one of Items 1 to 6, which is used for producing a polyurethane resin composition for sealing electrical and electronic parts.

  Item 8. A polyurethane resin composition comprising a polyisocyanate and the polyol composition according to any one of Items 1 to 7.

  Item 9. Item 9. An electrical and electronic component sealed with a polyurethane resin composition according to Item 8.

  By producing a polyurethane resin composition using the polyol composition of the present invention, foaming is further suppressed while containing an inorganic filler, and the polyurethane resin composition is excellent in thermal conductivity and curing stability. Product (hereinafter sometimes abbreviated as “polyurethane resin composition of the present invention”). Since the polyurethane resin composition of the present invention has such properties, it is particularly suitable for sealing electrical and electronic parts that require waterproofness and heat dissipation.

  In this specification, the expression “containing” includes the concepts of “including”, “consisting essentially of”, and “consisting only of”. Further, the expression “hydrogenated” means a hydrogen adduct.

1. Polyol composition The polyol composition of the present invention contains a polyol, an inorganic filler, and a catalyst, and the water content is adjusted to 0.2% or less by a heating treatment and / or a reduced pressure treatment, A polyol composition for producing a polyurethane resin composition. This will be described below.

  The polyol is not particularly limited as long as it is a polyol having two or more hydroxyl groups, and various types used in the polyurethane resin composition can be used. Examples of the polyol include ethylene glycol, 1,3-propanediol, 1,2-propanediol, 2methyl 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, and 1,4 pentane. Diol, 1,5-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 1,2-hexanediol, 2,5-hexanediol, octanediol, nonanediol, decanediol, diethylene glycol, triethylene Glycol, dipropylene glycol, cyclohexanediol, trimethylolpropane, glycerin, 2-methylpropane-1,2,3-triol, 1,2,6-hexanetriol, pentaerythritol, polylactone diol, polylactone triol, ester Recall, polyester polyol, polyether polyol, polycarbonate polyol, polybutadiene polyol, acrylic polyol, silicone polyol, fluorine polyol, polytetramethylene glycol, polypropylene glycol, polyethylene glycol, polycaprolactone polyol, castor oil-based polyol, dimer acid-based polyol, etc. Can be mentioned. Among these, it is preferable to use a castor oil-based polyol and / or a polybutadiene polyol.

  The castor oil-based polyol is not particularly limited, and examples thereof include castor oil and castor oil derivatives.

  The castor oil derivative is not particularly limited. For example, castor oil fatty acid; hydrogenated castor oil hydrogenated to castor oil or castor oil fatty acid; transesterified product of castor oil and other fats and oils; castor oil and polyhydric alcohol Reaction product: Esterification reaction product of castor oil fatty acid and polyhydric alcohol; those obtained by addition polymerization of alkylene oxide to these. Among the above castor oil-based polyols, it is preferable to use castor oil.

  The molecular weight of the castor oil-based polyol is usually in the range of 100 to 4000, and preferably in the range of 300 to 2500.

  In the castor oil-based polyol, the hydroxyl group content is usually in the range of 30 to 500 mgKOH / g, preferably in the range of 100 to 200 mgKOH / g, as the hydroxyl value.

  Examples of commercially available products that can be used as a castor oil-based polyol include Eulic H-30 (hydroxyl value 160, functional group number 3), Eulic H-57 (hydroxyl value 100, functional group number 3), Eulic H manufactured by Ito Oil Co., Ltd. -52 (hydroxyl value 200, functional group number 3) and the like.

  The polybutadiene polyol is not particularly limited as long as it has a polybutadiene structure and two hydroxyl groups in the molecule, and among them, those having hydroxyl groups at both ends of the chain polybutadiene structure are preferable. Examples of the polybutadiene polyol include poly (1,4-butanediene) polyol, poly (1,2-butadiene) polyol, poly (1,2- / 1,4-butadiene) polyol, and the like. The poly (1,2- / 1,4-butadiene) polyol has a repeating unit composed of polybutadiene having 60 to 90 mol% of 1,4 bonds and 10 to 40 mol% of 1,2 bonds, The number of repetitions is 10 to 14, and examples include polyols having hydroxyl groups at both ends. That is, the polybutadiene polyol may have a polybutadiene structure in which 1,3-butadiene is trans 1,4-bonded, or has a polybutadiene structure in which 1,3-butadiene is cis 1,4-bonded. Alternatively, it may have a polybutadiene structure in which 1,3-butadiene is bonded to 1,2. Moreover, you may have a polybutadiene structure in which these bonds were mixed.

  The molecular weight of the polybutadiene polyol is preferably 800 to 4800, and more preferably 1200 to 3000.

  The polybutadiene polyol may be a hydrogenated polybutadiene polyol. Examples of the hydrogenated polybutadiene polyol include those disclosed in JP-A-2-298574. Hydrogenated polybutadiene polyol is obtained by hydrogenation of the above polybutadiene polyol.

  The polybutadiene polyol has an average hydroxyl value determined according to JIS K1557-1 of preferably 20 to 250 mgKOH / g, and more preferably 50 to 120 mgKOH / g.

  500-5000 are preferable and, as for the number average molecular weight of the said polybutadiene polyol (A2), 1000-3500 are more preferable.

  The number average molecular weight can be measured by gel permeation chromatography (GPC) method (polystyrene conversion). The number average molecular weight according to the GPC method is specifically transferred from Shodex GPC System 21 manufactured by Showa Denko KK as a measuring device and Shodex LF-804 / KF-803 / KF-804 manufactured by Showa Denko KK as a column. Using NMP as a phase, it can be measured at a column temperature of 40 ° C. and calculated using a standard polystyrene calibration curve.

  Commercially available products that can be used as the non-hydrogenated polybutadiene polyol include, for example, polybutadiene diols mainly having repeating units of 1,4 bonds (for example, Polybd (trademark) R-15HT, Poly bd (trademark) R-45HT ( All of which are manufactured by Idemitsu Kosan Co., Ltd.), poly (1,2-butadiene) glycol (eg, G-1000, G-2000, G-3000 (all of which are Nippon Soda shares) Company))). Examples of commercially available products that can be used as hydrogenated polybutadiene diol include, for example, hydrogenated polybutadiene diols mainly having repeating units of 1,4 bonds (for example, polytail H and polytail HA (both manufactured by Mitsubishi Chemical Corporation)), 1 And hydrogenated polybutadiene diol mainly having repeating units of two bonds (for example, GI-1000, GI-2000, GI-3000 (all trade names: manufactured by Nippon Soda Co., Ltd.)). Among these commercially available products, R-15HT and R-45HT are preferably used.

  Polyols may be used alone or in combination of two or more.

  Although there is no restriction | limiting in particular in content of a polyol, 0.5-30 mass% is preferable with respect to 100 mass% of polyol compositions of this invention, and 1-25 mass% is more preferable.

  The inorganic filler is not particularly limited, and various types of those used in the polyurethane resin composition can be used. Examples of inorganic fillers include aluminum hydroxide, alumina, aluminum nitride, boron nitride, magnesium hydroxide, magnesium oxide, zeolite and the like. Among these, from the viewpoint of being excellent in thermal conductivity and flame retardancy and suitable for sealing electrical and electronic parts, metal hydroxides are preferred, and among the metal hydroxides, aluminum hydroxide is preferred. , Magnesium hydroxide and the like, more preferably aluminum hydroxide.

  The shape of the inorganic filler may be either spherical or irregular.

  The inorganic fillers may be used alone or in combination of two or more.

  The content of the inorganic filler is 50 to 85% by mass with respect to 100% by mass of the polyol composition of the present invention, from the viewpoint of thermal conductivity of the finally obtained polyurethane resin composition and from the viewpoint of processability. Is preferable, 55-85 mass% is more preferable, 60-80 mass% is further more preferable, 65-75 mass% is still more preferable.

  A polymerization catalyst is not specifically limited, What is used in a polyurethane resin composition can be used variously. As a polymerization catalyst, metal catalysts, such as an organic tin catalyst, an organic lead catalyst, and an organic bismuth catalyst, an amine catalyst etc. can be illustrated, for example. Examples of the organic tin catalyst include dioctyltin dilaurate, dibutyltin diacetate, dibutyltin dilaurate, and dioctyltin diacetate. Examples of the organic lead catalyst include lead octylate, lead octenoate, lead naphthenate and the like. Examples of the organic bismuth catalyst include bismuth octylate and bismuth neodecanoate. As amine catalysts, diethylenetriamine, triethylamine, N, N-dimethylcyclohexylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine, trimethylene Examples thereof include diamine, dimethylaminoethanol, bis (2-dimethylaminoethyl) ether and the like. Moreover, as a polymerization catalyst, you may use an organometallic compound, a metal complex compound, etc.

  The polymerization catalyst may be used alone or in combination of two or more.

  The content of the polymerization catalyst is preferably 0.00001 to 10% by mass and more preferably 0.0001 to 5% by mass with respect to 100% by mass of the polyol composition of the present invention.

  The polyol composition of the present invention may further contain a plasticizer as necessary.

  The plasticizer is not particularly limited, and various plasticizers used in polyurethane resin compositions can be used. Examples of the plasticizer include phthalic acid esters such as dioctyl phthalate, diisononyl phthalate and diundecyl phthalate; adipic acid esters such as dioctyl adipate and diisononyl adipate; Castor oil esters such as triglyceride triglycerides; trimellitic esters such as trioctyl trimellitate and triisononyl trimellitate; pyromellitic esters such as tetraoctyl pyromellitate and tetraisononyl pyromellitate Is mentioned. Among these, diisononyl phthalate is preferable.

  You may use a plasticizer individually or in mixture of 2 or more types.

  The content of the plasticizer is preferably 0.01 to 30% by mass and more preferably 1 to 20% by mass with respect to 100% by mass of the polyol composition of the present invention. By making content of a plasticizer in the said range, the mixing viscosity at the time of manufacture of a polyurethane resin composition can be made lower, without reducing the heat resistance of a polyurethane resin composition largely.

  The polyurethane resin composition of the present invention may further comprise a tackifier, a curing accelerator, a colorant, a chain extender, a crosslinking agent, a filler, a pigment, a filler, a flame retardant, a urethanization catalyst, and an ultraviolet absorber as necessary. Additives such as antioxidants, moisture absorbents, antifoaming agents, antifungal agents, and silane coupling agents can be blended.

  The amount of these components used may be appropriately determined according to the purpose of use so as not to inhibit the desired properties of the finally obtained polyurethane resin composition.

  The polyol composition of the present invention is characterized in that the water content is adjusted to 0.2% or less by heating treatment and / or decompression treatment. By being prepared in this way, foaming of the finally obtained polyurethane resin composition can be suppressed.

  The method for measuring the moisture content is not particularly limited, and examples thereof include a capacity method and a coulometric method. Among these, the capacity method is preferable. The measuring device is not particularly limited, but a Karl Fischer moisture meter is preferable.

  Although the minimum of a moisture content is not specifically limited, For example, it can be 0.01%.

  Although the method of a heating process and / or a pressure reduction process will not be specifically limited if the water content can be adjusted to 0.2% or less, For example, the method of including following process ac is mentioned.

(Step a) Step of reducing the water content of the composition by heating and / or reducing the pressure of the composition containing the polyol and the inorganic filler (Step b) A polymerization catalyst is added to the composition that has undergone step a. Step of adding (Step c) A step of reducing the water content of the composition by subjecting the composition after step b to a heating treatment and / or a reduced pressure treatment.

  In the step a, the “composition containing a polyol and an inorganic filler” can be blended with other components such as a plasticizer and an additive as necessary as long as it does not contain a polymerization catalyst.

  From the viewpoint of the effect of the present invention, the temperature condition of the heating treatment in step a is preferably 40 ° C to 130 ° C, more preferably 70 to 130 ° C, and further preferably 90 to 130 ° C. By setting to such a temperature range, it is also possible to suppress the volatilization of the plasticizer while removing the moisture adsorbed on the inorganic filler in a short time. In addition, the atmospheric pressure condition of the decompression treatment in the step a is preferably 2.7 kPa or less, more preferably 2.0 kPa or less, and further preferably 1.5 kPa or less from the viewpoint of the effect of the present invention. By setting the pressure in such a range, it is possible to more efficiently remove moisture and bubbles, and to reduce foaming at the time of curing and defoaming time at the time of use. In step a, it is preferable to perform the heating process and the decompression process at the same time.

  The time of the heating treatment and / or the decompression treatment in step a can be, for example, about 0.25 to 4 hours, preferably about 0.5 to 2 hours, and more preferably 0.75. It can be about ~ 1.5 hours.

  In step b, in addition to the polymerization catalyst, other components such as a plasticizer and an additive can be blended as necessary.

  From the viewpoint of the effect of the present invention, the temperature condition of the heating treatment in the step c is preferably 40 ° C to 70 ° C, more preferably 50 ° C to 70 ° C. By setting to such a temperature range, it is possible to suppress the volatilization of the catalyst while removing water in a short time. Moreover, the atmospheric pressure conditions of the pressure reduction treatment in the step a are preferably 2.7 kPa or less, more preferably 2.0 kPa or less, and further preferably 1.5 kPa or less. In step c, it is preferable to perform the heating process and the decompression process at the same time.

  The time for the heating treatment and / or the decompression treatment in step c can be, for example, about 0.25 to 4 hours, preferably about 0.5 to 2 hours, and more preferably 0.75. It can be about ~ 1.5 hours.

  The polyol composition of the present invention is used for production of a polyurethane resin composition. The obtained polyurethane resin composition is more suitable for sealing electric and electronic parts because foaming is further suppressed and heat conductivity and curing stability are excellent.

2. Polyurethane resin composition The polyurethane resin composition of the present invention contains a polyisocyanate and the above-described polyol composition of the present invention.

  The polyisocyanate is not particularly limited as long as it is a compound having two or more isocyanate groups, and various polyisocyanates used in the polyurethane resin composition can be used.

  As the polyisocyanate, it is preferable to use a modified isocyanurate, and by using this, the heat resistance of the polyurethane resin composition is excellent.

  Examples of such isocyanurate-modified products include compounds obtained by isocyanurate-modifying aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, aromatic polyisocyanate compounds, araliphatic polyisocyanate compounds, and the like.

  Examples of the aliphatic polyisocyanate compound include tetramethylene diisocyanate, dodecamethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and 2-methyl. Examples include pentane-1,5-diisocyanate and 3-methylpentane-1,5-diisocyanate.

  Examples of the alicyclic polyisocyanate compound include isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, and 1,3-bis (isocyanate methyl). And cyclohexane.

  Examples of the aromatic polyisocyanate compound include tolylene diisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate (MDI), 4,4′-dibenzyl diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate and the like can be mentioned.

  Examples of the araliphatic polyisocyanate compound include dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, and α, α, α, α-tetramethylxylylene diisocyanate.

  As the isocyanurate-modified product, an isocyanurate-modified product of an aliphatic polyisocyanate compound, an alicyclic polyisocyanate compound, or an aromatic polyisocyanate compound is preferable. preferable.

  Examples of the polyisocyanate include the above-mentioned aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, aromatic polyisocyanate compounds, and araliphatic polyisocyanate compounds in addition to the isocyanurate-modified products. An allophanate modified body, a carbodiimide modified body, an adduct modified body, etc. are mentioned. As these modified products, an isocyanurate modified product of an aliphatic polyisocyanate compound, an alicyclic polyisocyanate compound, or an aromatic polyisocyanate compound is preferable, and among them, an isocyanurate modified product of hexamethylene diisocyanate or diphenylmethane diisocyanate is more preferable. preferable.

  Examples of commercially available polyisocyanates include Millionate MTL (manufactured by Tosoh Corporation), Duranate TLA-100 (manufactured by Asahi Kasei Chemicals Corporation), Coronate HX (manufactured by HDI isocyanurate Nippon Polyurethane Co., Ltd.), and the like.

  Polyisocyanate may be used independently and may be used in mixture of 2 or more types.

  In the polyurethane resin composition of the present invention, the content of the polyisocyanate is not particularly limited, but is preferably 1 to 50% by mass and more preferably 5 to 40% by mass with respect to 100% by mass of the polyol.

  In the polyurethane resin composition of the present invention, the NCO / OH ratio between the polyisocyanate and the polyol is preferably 0.6 to 2.0, more preferably 0.7 to 1.5. .

  It does not specifically limit as a method to manufacture the polyurethane resin composition of this invention, It can manufacture by the conventionally well-known method employ | adopted as a method of manufacturing a polyurethane resin composition.

  As such a manufacturing method, the method including mixing the polyol composition (B agent) of this invention and the A agent containing a polyisocyanate compound is mentioned, for example.

  If the B agent contains a polyol, an inorganic filler, and a polymerization catalyst, and the A agent contains a polyisocyanate, other components such as a plasticizer and an additive may be either the A agent or the B agent. It may be contained.

  The polyurethane resin composition may be liquid before curing or may be cured. Examples of the method of curing the polyurethane resin composition include a method of curing the polyurethane resin composition with time by mixing the agent A and the agent B and reacting the polyol and the polyisocyanate. At this time, heating may be performed. The heating temperature is preferably about 40 to 120 ° C., and the heating time is preferably about 0.5 to 24 hours.

  When the polyurethane resin composition of the present invention is liquid before curing, the viscosity is preferably 600 Pa · s or less, and more preferably 400 Pa · s or less. In particular, the initial mixing viscosity (viscosity after 2 minutes from the start of mixing of agent A and agent B) is preferably 100 Pa · s or less. By setting the viscosity within the above range, the polyurethane resin composition of the present invention can exhibit higher workability. In the present specification, the viscosity of the polyurethane resin composition before curing is a value measured with a Brookfield viscometer at 23 ° C.

  The polyurethane resin composition of the present invention can be used as a sealing material. The polyurethane resin composition is more suitable for sealing electrical and electronic parts because foaming is further suppressed and thermal conductivity and curing stability are excellent. Examples of such electrical and electronic parts include transformers such as transformer coils, choke coils, and reactor coils, equipment control boards, and various sensors. Such electric and electronic parts are also one aspect of the present invention. The electric and electronic parts of the present invention can be used in electric washing machines, toilet seats, water heaters, water purifiers, baths, dishwashers, electric tools, automobiles, motorcycles, and the like.

  EXAMPLES The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

(1) Raw material <polyisocyanate> MDI isocyanate (trade name: Millionate MTL, manufactured by Tosoh Corporation)
<Plasticizer> Diisononyl phthalate (trade name: DINP, manufactured by JPLUS)
<Polyol 1> Polybutadiene polyol having an average hydroxyl value of 103 mgKOH / g (trade name: R-15HT, manufactured by Idemitsu Kosan Co., Ltd.)
<Polyol 2> Castor oil (trade name: castor oil, manufactured by Ito Oil Co., Ltd.)
<Polyol 3> Polypropylene glycol (trade name: D-1000, manufactured by Mitsui Chemicals)
<Inorganic filler> Aluminum hydroxide (trade name: H-32 Heidilite, Showa Denko)
<Polymerization catalyst> Dibutyltin dilaurate (trade name: TN-12, manufactured by Sakai Chemical Industry Co., Ltd.).

(2) Preparation of agent B
(2-1) Examples 1 to 5 and Comparative Examples 1 to 4
A polyol, a plasticizer, and an inorganic filler were added, mixed at 2000 rpm for 3 minutes using a mixer (trade name: Awatori Netaro, Shinki Co., Ltd.), and the resulting composition was charged into a reaction kettle. It dehydrated at 100-120 degreeC and 1.3 kPa or less over 1 hour. The polymerization catalyst was added and mixed there, and it dehydrated at 55-65 degreeC and 1.3 kPa or less over 1 hour. The obtained composition was used as B agent. For the water content of B agent, Karl Fischer moisture meter (MKA-610, manufactured by Kyoto Electronics Industry Co., Ltd.), dehydrated solvent CM (manufactured by Mitsubishi Chemical Corporation, solvent), titrant SS-Z (manufactured by Mitsubishi Chemical Corporation, titrant) And measured. The measurement results are as shown in Table 1.

(2-2) Examples 6 to 8
When adding a polyol, a plasticizer, and an inorganic filler to a mixer, it carried out similarly to Examples 1-5 and Comparative Examples 1-4 except also putting a polymerization catalyst simultaneously.

(3) Preparation of polyurethane resin composition Agent A was added to agent B according to the formulation shown in Table 1, and the mixture was mixed at 2000 rpm for 60 seconds using a mixer (trade name: manufactured by Aritori Netaro, Shinki Co., Ltd.). The viscosity at 23 ° C. (mixed initial viscosity) of the mixed solution 2 minutes after the start of mixing was measured using a Brookfield viscometer (Table 1). The obtained mixture was used as a polyurethane resin composition. In addition, as shown in Table 1, the equivalent number of isocyanate groups in the agent A (NCO / OH) with respect to 1 equivalent of active hydrogen (OH) in the agent B was “1.00”.

(4) Preparation of test piece The prepared polyurethane resin composition was poured into a mold for molding (130 × 60 × 20 mm). It was heated at 80 ° C. for 16 hours and then allowed to cure at room temperature for one day to obtain a test piece.

(5) Evaluation test According to the following method and evaluation criteria, the initial mixing viscosity, foamability, hardness, thermal conductivity, and curability were evaluated. The evaluation results are shown in Table 1.

(5-1) Mixing initial viscosity ○: Less than 600 Pa · s x: 600 Pa · s or more
(5-2) Foamability The presence or absence of foaming on the surface of the test piece was visually observed, and foamability was evaluated according to the following evaluation criteria.
○: No foaming Δ: Bubbles or cracks due to one or two foams ×: With foaming
(5-3) Hardness The hardness of the test piece was measured using an Asker rubber hardness meter A type manufactured by Kobunshi Keiki Co., Ltd., and the hardness was evaluated according to the following evaluation criteria.
○: Measurement value is A80 or less Δ: Measurement value is A81-90
X: The measured value is A91 or more
(5-4) Thermal conductivity The thermal conductivity of the test piece was measured using QTM-500 manufactured by Kyoto Electronics Industry Co., Ltd., and the thermal conductivity was evaluated according to the following evaluation criteria.
○: Thermal conductivity of 0.5 W / m · K or more ×: Thermal conductivity of less than 0.5 W / m · K
(5-5) The viscosity at 23 ° C. of the polyurethane resin composition was measured with a curable BH type rotational viscometer (manufactured by TOKI Sangyo Co., Ltd.), and the time during which the viscosity was twice the initial mixing viscosity was defined as the pot life. About Examples 6-8, preparation of B agent was compared with the example of the same mixing | blending performed by the method as described in " (2-1) Examples 1-5 and Comparative Examples 1-4." An increase within 10% was evaluated as ◯, and an increase of 10% or more was evaluated as ×.

Claims (8)

A polyurethane resin composition for sealing electrical and electronic parts , comprising a polyol, an inorganic filler, and a polymerization catalyst, wherein the water content is adjusted to 0.2% or less by heating treatment and / or decompression treatment Polyol composition for production. The polyol composition according to claim 1, wherein the inorganic filler is a metal hydroxide. The polyol composition according to claim 1 or 2, wherein the content of the inorganic filler is 50 to 85 mass% with respect to 100 mass% of the polyol composition. The polyol composition according to any one of claims 1 to 3, wherein the polyol is a polybutadiene polyol and / or a castor oil-based polyol. (Step a) a step of heating and / or decompressing a composition containing a polyol and an inorganic filler to reduce the water content of the composition;
(Step b) A step of adding a polymerization catalyst to the composition that has undergone step a, and (Step c) The composition that has undergone step b is subjected to a heating treatment and / or a reduced pressure treatment to reduce the water content of the composition. step a including a method of producing a polyol composition according to claim 1. The temperature condition of the heating treatment in the step a is 40 ° C to 130 ° C,
The temperature condition of the heating treatment in the step c is 40 ° C. to 70 ° C., and the atmospheric pressure condition of the pressure reduction treatment in the steps a and c is 2.7 kPa or less,
The method of claim 5. Containing a polyol composition according to any one of the polyisocyanate and the claims 1-4, electrical and electronic components for encapsulating the polyurethane resin composition. An electrical / electronic component sealed with the polyurethane resin composition according to claim 7 .