JP2017171752A - Polyurethane resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyurethane resin composition excellent in both of flexibility and bendability even with containing polycarbonate polyol.SOLUTION: There is provided a polyurethane resin composition containing polyol (A) containing polyacrylic polyol (A1) and polycarbonate polyol (A2), and polyisocyanate (B) with content of the polyacrylic polyol (A1) of 10 to 70 mass% based on the total 100 mass% of the polyacrylic polyol (A1) and the polycarbonate polyol (A2).SELECTED DRAWING: None

Description

  The present invention relates to a polyurethane resin composition and the like.

  Electrical and electronic parts are often sealed with resin in order to prevent the influence of external environmental factors (physical factors such as heat, vibration, and fall; ultraviolet rays; chemical factors such as moisture and salt). As the resin, a polyurethane resin is widely used from the viewpoint of good flexibility, wear resistance, low-temperature curability, electrical characteristics, and the like. In particular, sealing resins for electrical and electronic parts that can be used in high-temperature and high-humidity environments such as cars and water heaters are required to have high levels of hydrolysis resistance and heat resistance.

  Polycarbonate polyol is a component blended in various resins. For example, Patent Documents 1 and 2 disclose a flexible polyimide resin or an ultraviolet curable resin in which a polycarbonate polyol is blended.

JP 2006-307183 A JP 2008-297440 A

  While the present inventors are advancing research and development of polyurethane resins, polyurethane resins blended with polycarbonate polyols are excellent in hydrolysis resistance, weather resistance, chemical resistance, abrasion resistance, etc., but at room temperature. It has been found that there is a problem that the flexibility and flexibility are poor and the heat-resistant cycle is inferior. Such a problem is not desirable particularly when used for sealing electrical and electronic parts.

  Then, this invention makes it a subject to provide the polyurethane resin composition which is excellent in both a softness | flexibility and a flexibility while containing polycarbonate polyol. Furthermore, in addition to these characteristics, it is an object to provide a polyurethane resin composition capable of exhibiting excellent hydrolysis resistance and heat resistance at a higher level by blending a polycarbonate polyol.

  As a result of intensive studies in view of the above problems, the present inventors have found that a polyol (A) containing a polyacryl polyol (A1) and a polycarbonate polyol (A2), a polyisocyanate (B), and a polyisocyanate (B). The polyurethane resin composition (in the present specification, “book”, wherein the content of the acrylic polyol (A1) is 10 to 70% by mass with respect to 100% by mass in total of the polyacryl polyol (A1) and the polycarbonate polyol (A2). In some cases, the present invention can solve the above problems. The present inventors have completed the present invention by conducting further research based on this finding.

That is, the present invention includes the following embodiments:
Item 1. The polyol (A) containing the polyacryl polyol (A1) and the polycarbonate polyol (A2), and the polyisocyanate (B), and the polyacryl polyol (A1) content is the polyacryl polyol (A1) and the polycarbonate. The polyurethane resin composition, which is 10 to 70% by mass with respect to 100% by mass in total of the polyol (A2).
Item 2. Item 2. The polyurethane resin composition according to Item 1, wherein the content of the polyacrylic polyol (A1) is 40 to 70% by mass with respect to 100% by mass in total of the polyacrylic polyol (A1) and the polycarbonate polyol (A2). object.
Item 3. Item 3. The polyurethane resin composition according to Item 1 or 2, wherein the polyisocyanate (B) contains an isocyanurate body (B1) of an aliphatic polyisocyanate compound.
Item 4. Item 6. The polyurethane resin composition according to Item 3, wherein the content of the isocyanurate-modified product (B1) of the aliphatic polyisocyanate compound is 60 to 100% by mass with respect to 100% by mass of the polyisocyanate (B).
Item 5. Item 5. The polyurethane resin composition according to Item 4, wherein the polyisocyanate (B) further contains a polynuclear body (B2) of an aromatic polyisocyanate compound.
Item 6. Item 6. The polyurethane resin composition according to Item 5, wherein the polyisocyanate (B) further contains a carbodiimide body (B3) of an aromatic polyisocyanate compound.
Item 7. The total content of the polynuclear body (B2) of the aromatic polyisocyanate compound and the carbodiimide body (B3) of the aromatic polyisocyanate compound is 5 to 30% by mass with respect to 100% by mass of the polyisocyanate (B). 5. A polyurethane resin composition according to item 5 or 6.
Item 8. The polycarbonate polyol (A2) has the general formula (1):

[In General Formula (1): R ¹ represents an alkylene group having 2 to 20 carbon atoms. n shows the integer of 1-40. ]
Item 8. The polyurethane resin composition according to any one of Items 1 to 7, which is a compound represented by:
Item 9. Item 9. The polyurethane resin composition according to any one of Items 1 to 8, wherein the polyacryl polyol (A1) is a polyacryl polyol having a hydroxyl group at the end of the main chain.
Item 10. Item 10. The polyurethane resin composition according to any one of Items 1 to 9, which is used for sealing electric and electronic parts.
Item 11. Item 10. An electrical / electronic component sealed with the polyurethane resin composition according to any one of Items 1 to 10.

  The polyurethane resin composition of the present invention is excellent in both flexibility and flexibility while containing a polycarbonate polyol. Moreover, in the preferable aspect, the outstanding hydrolysis resistance and heat resistance by the mixing | blending of polycarbonate polyol can be exhibited at a higher level. Furthermore, it is possible to exhibit excellent electrical characteristics. Therefore, the polyurethane resin composition of the present invention is suitable, for example, for resin sealing of electric and electronic parts, particularly for resin sealing of electric and electronic parts that can be used in a high temperature and high humidity environment.

  In this specification, the expressions “containing” and “including” include the concepts of “containing”, “including”, “consisting essentially of”, and “consisting only of”.

1. Polyurethane resin composition In one embodiment, the present invention contains a polyacryl polyol (A1) and a polyol (A) containing a polycarbonate polyol (A2), and a polyisocyanate (B), and a polyacryl polyol (A1). ) Content of the polyacrylic polyol (A1) and the polycarbonate polyol (A2) is 10 to 70% by mass with respect to the total of 100% by mass. This will be described below.

  In the present specification, the “polyol” is not particularly limited as long as it is a compound containing one or more hydroxyl groups.

  In the polyurethane resin composition of the present invention, the “polyol (A)” contains a polyacryl polyol (A1) and a polycarbonate polyol (A2).

  The polyacryl polyol (A1) is not particularly limited as long as it is a homopolymer or copolymer of at least one monomer selected from the group consisting of acrylic acid esters and methacrylic acid esters and has one or more hydroxyl groups. In other words, the polyacryl polyol (A1) contains, for example, at least 50% by mass (preferably 60% by mass) of at least one monomer unit selected from the group consisting of an acrylic ester monomer unit and a methacrylic ester monomer unit. % Or more, more preferably 70% by mass or more, further preferably 80% by mass or more, still more preferably 90% by mass or more, and particularly preferably 95% by mass or more).

  Here, the monomer unit means a divalent group derived from an acrylic ester or methacrylic ester in a polymer obtained by radical polymerization of an acrylic ester or methacrylic ester. For example, the methyl acrylate monomer unit is the following formula:

It is a bivalent group represented by these.

  Although the number of the hydroxyl groups which polyacryl polyol (A1) has is not restrict | limited in particular, For example, 1-5, Preferably it is 1-4, More preferably, it is 1-3, More preferably, it is 1-2, More preferably, it is 1. . The position of the hydroxyl group is not particularly limited, and may be either on the side chain or at the end of the main chain. The position of the hydroxyl group is preferably the end of the main chain. The polyacryl polyol (A1) is preferably a polyacryl polyol having a hydroxyl group at the end of the main chain.

  Although it does not restrict | limit especially as a monomer, For example, acrylic acid ester (or methacrylic acid ester) which does not have an aromatic ring and a cyclohexyl group, acrylic acid ester (or methacrylic acid ester) which has an aromatic ring, acrylic acid which has a cyclohexyl group Examples thereof include esters (or methacrylic acid esters).

  Examples of the acrylic acid ester (or methacrylic acid ester) having no aromatic ring and cyclohexyl group include methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), and butyl acrylate (n-, i -, S-, t-), pentyl acrylate (n-, i-, s-), hexyl acrylate (n-, i-), heptyl acrylate (n-, i-), octyl acrylate (n -, I-), nonyl acrylate (n-, i-), myristyl acrylate (n-, i-), acrylic acid (2-ethylhexyl), acrylic acid (ε-caprolactone), acrylic acid (2-hydroxy Ethyl), acrylic acid (2-hydroxypropyl), acrylic acid (3-hydroxypropyl), acrylic acid (4-hydroxybutyl), acrylic acid (2-hydroxy) Chill), acrylic acid (2-methoxyethyl), acrylic acid (2-ethoxyethyl), or the acrylic acid ester may include those obtained by changing the methacrylic acid ester.

  As an acrylic ester (or methacrylic ester) having an aromatic ring, phenyl acrylate, phenyl methacrylate, acrylic acid (2 or 4-chlorophenyl), methacrylic acid (2 or 4-chlorophenyl), acrylic acid (2 or 3) Or 4-ethoxycarbonylphenyl), methacrylic acid (2 or 3 or 4-ethoxycarbonylphenyl), acrylic acid (o or m or p-tolyl), methacrylic acid (o or m or p-tolyl), benzyl acrylate, Examples include benzyl methacrylate, phenethyl acrylate, phenethyl methacrylate, and acrylic acid (2-naphthyl).

  Examples of the acrylic acid ester (or methacrylic acid ester) having a cyclohexyl group include cyclohexyl acrylate, cyclohexyl methacrylate, acrylic acid (4-methylcyclohexyl), methacrylic acid (4-methylcyclohexyl), and acrylic acid (4-ethyl). Cyclohexyl) and methacrylic acid (4-ethylcyclohexyl).

  A monomer can also be used individually by 1 type and can also be used in combination of arbitrary 2 or more types.

  Among these, as a monomer, Preferably, an acrylic ester (or methacrylic ester) which does not have an aromatic ring and a cyclohexyl group is mentioned, Preferably ester of acrylic acid and a C1-C10 alcohol is mentioned. More preferably, methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-), or the like, or these are changed to methacrylate esters. More preferred are methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate and the like, and particularly preferred are methyl acrylate, methyl methacrylate and the like. The monomer is preferably an acrylic ester.

  The content of the monomer units of these preferable monomers is, for example, 30% by mass or more, preferably 40% by mass or more, more preferably 50% by mass or more, further preferably 60% by mass or more, in the polyacryl polyol (A1). More preferably, it is 70 mass% or more.

  The polyacryl polyol (A1) can be produced according to or according to a known method. For example, the polyacryl polyol (A1) having a hydroxyl group at the end of the main chain is a method using a radical polymerization initiator having a hydroxyl group such as azobis (2-hydroxyethylbutyrate), or a hydroxyl group such as 2-mercaptoethanol. A method of using a chain transfer agent having a hydroxyl group, a method of using a polymerization terminator having a hydroxyl group, a method of having a hydroxyl group at the terminal by living ion polymerization, as disclosed in JP-A No. 2000-128911 or 2000-344823 It can be obtained by a bulk polymerization method using a compound having a single thiol group and a secondary hydroxyl group, or a polymerization catalyst in which the compound and an organometallic compound are used in combination.

  The average hydroxyl value of the polyacryl polyol (A1) is not particularly limited, but is, for example, 20 to 250 mgKOH / g, preferably 40 to 200 mgKOH / g, more preferably 60 to 150 mgKOH / g, and still more preferably 80 to 120 mg KOH / g.

  Although the number average molecular weight of polyacryl polyol (A1) is not specifically limited, For example, it is 200-5000, Preferably it is 400-3000, More preferably, it is 600-2000, More preferably, it is 800-1500. In the present specification, the number average molecular weight can be measured by gel permeation chromatography (GPC) method (polystyrene conversion). Specifically, the number average molecular weight by the GPC method is 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. Measured at a column temperature of 40 ° C. using NMP as a mobile phase, and can be calculated using a standard polystyrene calibration curve.

  The viscosity of the polyacryl polyol (A1) is not particularly limited, but at 25 ° C., for example, 200 to 30000 mPa · s, more preferably 1000 to 20000 mPa · s, still more preferably 2000 to 15000 mPa · s, and even more. Preferably it is 5000-12000 mPa * s.

  As a commercial item of polyacryl polyol (A1), for example, Act Flow Series manufactured by Soken Chemical Co., Ltd. and the like can be mentioned.

  A polyacryl polyol (A1) can also be used individually by 1 type, and can also be used in combination of arbitrary 2 or more types.

  Content of a polyacryl polyol (A1) is 10-70 mass% with respect to a total of 100 mass% of a polyacryl polyol (A1) and a polycarbonate polyol (A2). The content is such that the flexibility and / or flexibility can be further improved and higher heat resistance can be exhibited, so that the total of 100% by mass of the polyacryl polyol (A1) and the polycarbonate polyol (A2). For example, it is 30-70 mass%, Preferably it is 40-70 mass%, More preferably, it is 40-60 mass%, More preferably, it is 45-55 mass%.

  The polycarbonate polyol (A2) is not particularly limited as long as it has a structure in which monomer units are bonded with a carbonate group (—O— (C═O) —O—) and has one or more hydroxyl groups.

  Although the number of the hydroxyl group which polycarbonate polyol (A2) has is not restrict | limited in particular, For example, 1-5, Preferably it is 2-4, More preferably, it is 2-3, More preferably, it is 2. The position of the hydroxyl group is not particularly limited, and may be either on the side chain or at the end of the main chain. The position of the hydroxyl group is preferably the end of the main chain. The polycarbonate polyol (A2) is preferably a polycarbonate diol having hydroxyl groups at both ends of the main chain.

  Examples of the polycarbonate polyol (A2) include a general formula:

[In the general formula (1): each R ¹ independently represents an alkylene group. n shows the integer of 1-40. ]
The compound represented by these is mentioned.

The alkylene group represented by R ¹ includes both linear and branched ones. The number of carbon atoms is not particularly limited, but is, for example, 2 to 20, preferably 3 to 15, more preferably 3 to 10, still more preferably 3 to 8, still more preferably 4 to 7, particularly preferably 5 to 6. . The alkylene group is preferably linear. Specific examples of the alkylene group include an ethylene group, an n-propylene group, an n-butylene group, an n-pentylene group, an n-hexylene group, an n-heptylene group, an n-octylene group, and an n-dodecylene group. Can be mentioned.

In the general formula (1), R ¹ is preferably composed of two different alkylene groups (an alkylene group a and an alkylene group b having more carbon atoms than the alkylene group a). The difference in carbon number between the alkylene group a and the alkylene group b is, for example, 1 to 5, preferably 1 to 3, more preferably 1 to 2, and still more preferably 1. The alkylene group a is, for example, linear or branched (preferably linear) carbon number 2-9 (preferably 2-7, more preferably 3-6, still more preferably 4-6, particularly 4-6. Preferably, an alkylene group of 5) is mentioned. As the alkylene group b, for example, a linear or branched (preferably linear) carbon number of 3 to 10 (preferably 3 to 8, more preferably 4). -7, more preferably 5-7, particularly preferably 6) alkylene groups. The molar ratio of the alkylene group a to the alkylene group b (alkylene group a: alkylene group b) is, for example, 0.5: 1.5 to 1.5: 0.5, preferably 0.8: 1.2 to 1. .2: 0.8, more preferably 0.9: 1.1 to 1.1: 0.9.

  The polycarbonate polyol (A2) can be produced according to or according to a known method. For example, a method of performing a dealcoholization reaction or a dephenol reaction between a bifunctional alcohol and a carbonate compound, a method of transesterifying a high molecular weight polycarbonate polyol with a polyhydric alcohol, or the like can be given.

  The average hydroxyl value of the polycarbonate polyol (A2) is not particularly limited, but is, for example, 50 to 400 mgKOH / g, preferably 100 to 350 mgKOH / g, more preferably 150 to 300 mgKOH / g, and further preferably 180 to 280 mgKOH. / G.

  Although the number average molecular weight of polycarbonate polyol (A2) is not specifically limited, For example, it is 100-3000, Preferably it is 200-2000, More preferably, it is 300-1000, More preferably, it is 350-700.

  The viscosity of the polycarbonate polyol (A2) is not particularly limited, but is, for example, 50 to 2000 mPa · s, more preferably 100 to 1000 mPa · s, and further preferably 150 to 500 mPa · s at 25 ° C.

  As a commercial item of polycarbonate polyol (A2), Asahi Kasei Chemicals Co., Ltd. Duranol series etc. are mentioned, for example.

  Polycarbonate polyol (A2) can also be used individually by 1 type, and can also be used in combination of arbitrary 2 or more types.

  Content of polycarbonate polyol (A2) is 30-90 mass% with respect to a total of 100 mass% of polyacryl polyol (A1) and polycarbonate polyol (A2). From the viewpoint that the content can further improve flexibility and / or flexibility and higher heat resistance, the total of the polyacryl polyol (A1) and the polycarbonate polyol (A2) can be obtained. It is 20-70 mass% with respect to 100 mass%, Preferably it is 30-60 mass%, More preferably, it is 40-60 mass%, More preferably, it is 45-55 mass%.

  The polyol (A) may contain other polyols in addition to the polyacrylic polyol (A1) and the polycarbonate polyol (A2). As the other polyol, it is possible to use various components used or usable in the polyurethane resin composition (particularly, the polyurethane resin composition for sealing electric and electronic parts). Specific examples of other polyols include castor oil-based polyols, polybutadiene polyols, dimer acid polyols, polyether polyols, polyester polyols, polycaprolactone polyols, hydrides thereof (for example, hydrogenates of polybutadiene polyols, hydrogens of polyisoprene polyols). Hydrides of polydiene polyols such as hydrides; hydrides of castor oil, etc.).

  The total content of the polyacryl polyol (A1) and the polycarbonate polyol (A2) is, for example, 60 to 100% by mass, preferably 80 to 100% by mass, and more preferably 90 to 100% with respect to 100% by mass of the polyol (A). It is 95 mass%, More preferably, it is 95-100 mass%, More preferably, it is 98-100 mass%.

  A polyol (A) can also be used individually by 1 type, and can also be used in combination of arbitrary 2 or more types.

  The content of the polyol (A) is not particularly limited as long as it is an amount that can be employed in a polyurethane resin composition (particularly, a polyurethane resin composition for sealing electrical and electronic parts). The content is, for example, 5 to 90% by mass with respect to 100% by mass of the polyurethane resin composition of the present invention. If the polyurethane resin composition of the present invention does not contain an inorganic filler, the content thereof is, for example, 30 to 90% by mass, preferably 40 to 80% with respect to 100% by mass of the polyurethane resin composition of the present invention. It is 50 mass%, More preferably, it is 50-75 mass%.

  “Polyisocyanate (B)” is not particularly limited as long as it has two or more isocyanate groups, or a component used in a polyurethane resin composition (particularly, a polyurethane resin composition for sealing electric and electronic parts) or Various components that can be used can be used. Examples of the polyisocyanate (B) include polyisocyanate compounds such as aliphatic polyisocyanate compounds, alicyclic polyisocyanate compounds, aromatic polyisocyanate compounds, and araliphatic polyisocyanate compounds; modified polyisocyanate compounds (for example, Isocyanurate body, carbodiimide body, adduct body, biuret body, allophanate body, etc.), polynuclear bodies of polyisocyanate compounds, and the like.

  Among these, from the viewpoint that heat resistance and hydrolysis resistance can be further improved, (B1) isocyanurate bodies of polyisocyanate compounds (more preferably isocyanurate bodies of aliphatic polyisocyanate compounds) are mentioned. It is done. In addition to these preferred polyisocyanates, the polyisocyanate (B) can further reduce the dielectric constant (that is, improve the electrical characteristics), and further (B2) a polynuclear compound of a polyisocyanate compound ( Preferably, it contains an aromatic polyisocyanate compound polynuclear body). In this case, in addition to the polyisocyanate (B2) of the polyisocyanate compound, the polyisocyanate (B) can further reduce the dielectric loss tangent (that is, further improve the electrical characteristics), and further (B3) A carbodiimide body of a polyisocyanate compound (preferably, a carbodiimide body of an aromatic polyisocyanate compound) may be contained.

  Examples of the aliphatic polyisocyanate compound include tetramethylene diisocyanate, dodecamethylene diisocyanate, hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, Examples include 2-methylpentane-1,5-diisocyanate and 3-methylpentane-1,5-diisocyanate, and preferably hexamethylene diisocyanate (HDI).

  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, preferably 2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4 ′. -Diphenylmethane diisocyanate (MDI) etc. are mentioned.

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

  The viscosity of the polyisocyanate (B) varies greatly depending on the type of polyisocyanate compound and the presence or absence of modification, but is not particularly limited. For example, in the case of an aromatic polyisocyanate compound and a modified product and a polynuclear product thereof (preferably a carbodiimide product and a polynuclear product of an aromatic polyisocyanate compound), the viscosity at 25 ° C. is, for example, 5 to 200 mPa · s, preferably 10 It is -150 mPa * s, More preferably, it is 15-100 mPa * s, More preferably, it is 20-80 mPa * s. As another example, in the case of an aliphatic polyisocyanate compound and modified products and polynuclear products thereof (preferably an isocyanurate form of an aliphatic polyisocyanate compound), the viscosity at 25 ° C. is, for example, 100 to 3000 mPa · s, preferably It is 500-2500 mPa * s, More preferably, it is 1000-2000 mPa * s, More preferably, it is 1200-1700 mPa * s.

  The NCO content of the polyisocyanate (B) is not particularly limited, but is, for example, 15 to 45%, more preferably 20 to 40%, and further preferably 20 to 35%.

  Examples of commercially available products of polyisocyanate (B) include Millionate MTL (manufactured by Tosoh Corporation), Duranate TPA-100 (manufactured by Asahi Kasei Chemicals Corporation), and lupranate M5S (manufactured by BASF INOAC polyurethane).

  Polyisocyanate (B) can also be used individually by 1 type, and can also be used in combination of arbitrary 2 or more types.

  The content of the polyisocyanate (B) is not particularly limited as long as it is an amount that can be employed in a polyurethane resin composition (particularly, a polyurethane resin composition for sealing electrical and electronic parts). This content is 15-80 mass parts with respect to 100 mass parts of polyol (A), Preferably it is 25-75 mass parts, More preferably, it is 35-70 mass parts.

  When the polyisocyanate (B) contains an isocyanurate of a polyisocyanate compound (more preferably an isocyanurate of an aliphatic polyisocyanate compound), the content further improves heat resistance and hydrolysis resistance. From the viewpoint that it can be used, for example, 50 to 100% by mass, preferably 60 to 100% by mass, more preferably 70 to 100% by mass, and further preferably 70 to 90% by mass with respect to 100% by mass of the polyisocyanate (B). %, More preferably 75 to 85% by mass.

  In addition to (B1) the isocyanurate of the polyisocyanate compound (more preferably, the isocyanurate of the aliphatic polyisocyanate compound), the polyisocyanate (B) is further a polynuclear (preferably aromatic) of the (B2) polyisocyanate compound. Or (B2) polyisocyanate of polyisocyanate compound (preferably polynuclear of aromatic polyisocyanate compound) and (B3) carbodiimide of polyisocyanate compound (preferably In the case of containing a carbodiimide body of an aromatic polyisocyanate compound), the total content of (B2) and (B3) can be increased to 100% by mass of polyisocyanate (B) from the viewpoint that electrical characteristics can be further improved. For example, 5 to 50 mass , Preferably 5 to 40 mass%, more preferably 5 to 30 mass%, more preferably 10 to 30 mass%, even more preferably 15 to 25 wt%.

  In the polyurethane resin composition of the present invention, the NCO / OH ratio between the polyisocyanate (B) and the polyol (A) is preferably 0.6 to 2.0, and preferably 0.8 to 1.2. It is more preferable.

  The polyurethane resin composition of the present invention preferably contains “antifoaming agent (C)”.

  The antifoaming agent (C) is not particularly limited, and various components that can be used or can be used in the polyurethane resin composition (particularly, the polyurethane resin composition for sealing electric and electronic parts) can be used. Examples of the antifoaming agent (C) include silicones (oil type, compound type, self-emulsifying type, emulsion type, etc.), alcohols and the like. Among these, silicones (silicone-based antifoaming agents) are preferable, and among silicones, modified silicone-based antifoaming agents (especially those having polysiloxane as a lipophilic group and modified with a hydrophilic group) are preferable. Can be mentioned.

  An antifoamer (C) can also be used individually by 1 type, and can also be used in combination of arbitrary 2 or more types.

  Although content in particular of an antifoamer (C) is not restrict | limited, For example, it is 0.001-10 mass parts with respect to 100 mass parts of polyols (A), Preferably it is 0.01-5 mass parts.

  The polyurethane resin composition of the present invention may contain a “polymerization catalyst (D)” as necessary. A polymerization catalyst (D) is not specifically limited, The component currently used in the polyurethane resin composition (especially polyurethane resin composition for electrical / electronic component sealing) or the component which can be used can be used variously. As a polymerization catalyst (D), 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.

  A polymerization catalyst (D) can also be used individually by 1 type, and can also be used in combination of arbitrary 2 or more types.

  Although content in particular of a polymerization catalyst (D) is not restrict | limited, For example, 0.00001-10 mass parts with respect to 100 mass parts of polyol (A), Preferably it is 0.0001-5 mass parts, More preferably, it is 0.00. It is 001-1 mass part, More preferably, it is 0.005-0.2 mass part.

  The polyurethane resin composition of the present invention can contain various “additives” as necessary. An additive will not be specifically limited if it is a component which can be used for a polyurethane resin composition (especially the polyurethane resin composition for electrical / electronic component sealing). Specific examples of additives include plasticizers, inorganic fillers, moisture adsorbents, silane coupling agents, tackifiers, curing accelerators, colorants, chain extenders, crosslinking agents, fillers, pigments, flame retardants, urethanes Examples thereof include an oxidation catalyst, an ultraviolet absorber, an antioxidant, and an antifungal agent.

  The content of these additives can be appropriately determined in accordance with the purpose of use so as not to impair the desired properties of the polyurethane resin composition from a range comparable to the usual addition amount.

  In addition, a foaming agent is not added to the polyurethane resin composition of this invention. That is, the polyurethane resin composition of the present invention is mainly intended for resin sealing of electrical and electronic parts, whereas the foamed urethane foam containing a foaming agent is intended for heat insulation and the like. Is different.

  When the polyurethane resin composition of the present invention is in a liquid state before curing, the viscosity is preferably 1000 mPa · s or less, and more preferably 500 mPa · s or less. If it is a viscosity of such a range, higher workability | operativity can be shown.

  In addition, in this specification, the viscosity of the polyurethane resin composition before hardening is a value measured by the measuring method shown below. That is, a polyol-containing component is prepared as a B component, mixed at 2000 rpm for 3 minutes using a mixer (trade name: Awatori Nertaro, Shinki Co., Ltd.), and then adjusted to 23 ° C. Separately, a component containing polyisocyanate is prepared as component A and adjusted to 23 ° C. Next, the A component is added to the B component and mixed for 60 seconds. The viscosity of the mixed solution after 3 minutes from the start of mixing is measured using a BH viscometer, and is used as a measured value of the viscosity (mixed initial viscosity) of the polyurethane resin composition before curing.

2. Method for Producing Polyurethane Resin Composition The method for producing the polyurethane resin composition of the present invention is not particularly limited, and it is produced according to a conventionally known method used as a method for producing a polyurethane resin composition, or a method analogous thereto. be able to.

  As such a production method, for example, a polyurethane resin is prepared by preparing a component containing polyisocyanate and preparing a component A and a component including a polyol to prepare a component B, and mixing and mixing the components A and B. The method of manufacturing the polyurethane resin composition containing the said polyurethane resin is mentioned.

  If the A agent contains polyisocyanate and the B agent contains a polyol, the other component may be contained in either the A component or the B component. Preferably, the A agent contains polyisocyanate, and the B agent contains a polyol and other components (an antifoaming agent, a polymerization catalyst, etc.) added as necessary.

  In preparation of agent B, it is desirable to dehydrate the mixture of each component of agent B by heating and / or decompression. From the viewpoint of the effect of the present invention, the temperature condition for the heating treatment is preferably 40 ° C to 70 ° C, more preferably 50 to 70 ° C. From the viewpoint of the effect of the present invention, the atmospheric pressure condition of the decompression treatment is preferably 30 mmHg or less, more preferably 20 mmHg or less, and further preferably 10 mmHg or less. In the dehydration process, it is preferable to perform the heating process and the decompression process simultaneously. The time for the heating treatment and / or the decompression treatment is, for example, about 0.25 to 5 hours, preferably about 0.5 to 4 hours, and more preferably about 1 to 3 hours.

  The polyurethane resin composition of the present invention may be in a liquid state before curing, or may be partially or wholly cured. As a method of curing the polyurethane resin composition, there is a method of curing the polyurethane resin composition over time by mixing the A agent and the B agent to react a polyisocyanate and a polyol to obtain a polyurethane resin. Although mentioned, you may make it harden | cure by heating. In this case, the heating temperature is not particularly limited as long as curing occurs, and can be appropriately set according to the heating time. The heating temperature is preferably about 40 to 120 ° C. (more preferably about 50 to 80 ° C.). The heating time for curing by heating is not particularly limited as long as curing occurs, and can be appropriately set according to the heating temperature. The heating time is preferably about 0.1 to 24 hours (more preferably about 8 to 20 hours). After heating, if necessary, it may be further cured, for example, by standing at room temperature (for example, 8 to 48 hours, preferably 16 to 32 hours).

3. Use of polyurethane resin composition The polyurethane resin composition of the present invention is excellent in both flexibility and flexibility even though it contains polycarbonate polyol. Moreover, in the preferable aspect, the outstanding hydrolysis resistance and heat resistance by the mixing | blending of polycarbonate polyol can be exhibited at a higher level. Furthermore, it is possible to exhibit excellent electrical characteristics. Therefore, the polyurethane resin composition of the present invention is suitable, for example, for resin sealing of electric and electronic parts, particularly for resin sealing of electric and electronic parts that can be used in a high temperature and high humidity environment.

  Examples of such electric 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) Preparation of polyurethane resin composition A polyurethane resin composition was prepared according to the formulation shown in Table 1 (the unit of numerical values is parts by mass). The preparation procedure is as follows. Each component of B agent of Table 1 was mixed for 3 minutes at 2000 rpm using the mixer (Brand name: Nertaro Awatori, Shinki Co., Ltd.). This was put into a reaction kettle equipped with a device capable of heating, cooling, stirring, and depressurization in a sealed state so that moisture in the air was not mixed. In the reaction kettle, dehydration was carried out at a temperature of 60 ° C. under a pressure of 10 mmHg or less for 2 hours to prepare B agent. This B agent and the A agent containing polyisocyanate (the polyisocyanate content is adjusted so that the NCO / OH ratio is 1.0) are mixed for 1 minute at 2000 rpm using a mixer. And defoamed. The obtained mixture was used as a polyurethane resin composition in the following “(2) Preparation of test piece”.

Raw material <MTL> Carbodiimide modified MDI (Product name: Millionate MTL, manufactured by Tosoh Corporation)
<TPA> Modified HDI isocyanurate (Product name: Duranate TPA-100, manufactured by Asahi Kasei Chemicals)
<M5S> Polymeric MDI (Product name: Lupranate M5S, manufactured by BASF INOAC polyurethane)
<Polyacryl polyol> Polyacryl polyol (Product name: Actflow UMM-1001)
<Polycarbonate polyol> Polycarbonate diol (Product name: Duranol T5650E, manufactured by Asahi Kasei Chemicals)
<SC-5570> Silicone antifoaming agent (Product name: SC-5570, manufactured by Toray Dow Corning)
<U-810> Dioctyltin dilaurate (product name: Neostan U-810, manufactured by Nitto Kasei Co., Ltd.).

(2) Preparation of test piece The prepared polyurethane resin composition was poured into a molding die A of 130 mm × 130 mm × 3 mm, heated at 80 ° C. for 16 hours, and allowed to cure at room temperature for 1 day. A was obtained. Further, the test piece B was replaced with the molding die A in the same manner as the production method of the test piece A except that a molding die B of 130 mm × 130 mm × 1 mm was used instead of the molding die A. A test piece C was obtained in the same manner as the preparation method of the test piece A, except that a 10 mm thick mold C was used. Using the test pieces A to C, hardness, heat resistance, flexibility, flexibility, electrical properties, and hydrolysis resistance were measured and evaluated by the following methods.

(3) The hardness (type A) when the temperature of the hardness test piece C was 23 ° C. was measured according to JIS K6253 using a hardness meter (manufactured by Kobunshi Keiki Co., Ltd., Asker rubber hardness meter A type). The results are shown in Table 1.

(4) Heat resistance test piece C was heated in a dryer at 150 ° C. for 3 hours. After heating, the presence or absence of melting of the test piece was visually determined, and the heat resistance was evaluated according to the following evaluation criteria. The results are shown in Table 1.
○: No melting.
X: There is melting.

(5) Flexibility (Elongation rate)
The elongation percentage (flexibility) of the test piece A was evaluated based on the following formula according to JIS K 6251.
Formula: Elongation rate = {[(Distance between marked lines at break) − (Distance between marked lines)] ÷ (Distance between marked lines)} × 100
○: Elongation rate is 200% or more.
Δ: Elongation rate is 100% or more and less than 200%.
X: Elongation rate is less than 100%.

(6) Flexibility A force was applied to the test piece A at room temperature to bend at 90 degrees (° C.) to evaluate whether or not it was bent. Furthermore, it was evaluated whether or not the bent test piece returned to a flat surface without applying a force. Based on the results, the flexibility was evaluated according to the following evaluation criteria. The results are shown in Table 1.
○: Turns 90 degrees and returns to a flat surface naturally.
Δ: bends 90 degrees, but does not return naturally flat.
X: It does not bend at 90 degrees.

(7) Electrical characteristics 1
The volume resistivity of the test piece A was measured using a resistance measuring instrument (manufactured by HIOKI, DSM-8104). Based on the measurement results, the electrical characteristics were evaluated according to the following evaluation criteria. The results are shown in Table 1.
○: Volume resistivity is 1 × 10 ¹² Ω · cm or more.
X: Volume resistivity is less than 1 × 10 ¹² Ω · cm.

(8) Electrical characteristics 2
The dielectric constant of the test piece B was measured using a dielectric loss measuring device (manufactured by HIOKI, LCR HiTester 3532-50). Based on the measurement results, the electrical characteristics were evaluated according to the following evaluation criteria. The results are shown in Table 1.
○: Dielectric constant (1 kHz) is less than 4.00.
Δ: Dielectric constant (1 kHz) is 4.00 or more and less than 8.00.
X: Dielectric constant (1 kHz) is 8.00 or more.

(9) The hydrolysis resistance test piece C was subjected to a pressure cooker test. The conditions were 121 ° C. and 100% RH. From the start of the test to the elapse of 300 hours, the presence or absence of melting and the presence or absence of foaming were visually evaluated. After 300 hours from the start of the test, the hardness (type A) of the unmelted test piece was measured according to JIS K6253 using a hardness meter (manufactured by Kobunshi Keiki Co., Ltd., Asker rubber hardness meter A type).
A: There is no melting even after 300 hours from the start of the test, and the hardness is 40 or more.
○: There is no melting until 200 hours after the start of the test.
(Triangle | delta): There is no fusion | melting until 150 hours after a test start.
X: There is foaming.

Claims (11)

  The polyol (A) containing the polyacryl polyol (A1) and the polycarbonate polyol (A2), and the polyisocyanate (B), and the polyacryl polyol (A1) content is the polyacryl polyol (A1) and the polycarbonate. The polyurethane resin composition which is 10-70 mass% with respect to a total of 100 mass% of a polyol (A2).   The polyurethane resin according to claim 1, wherein the content of the polyacryl polyol (A1) is 40 to 70% by mass with respect to 100% by mass in total of the polyacryl polyol (A1) and the polycarbonate polyol (A2). Composition.   The polyurethane resin composition according to claim 1 or 2, wherein the polyisocyanate (B) contains an isocyanurate body (B1) of an aliphatic polyisocyanate compound.   The polyurethane resin composition according to claim 3, wherein the content of the isocyanurate-modified product (B1) of the aliphatic polyisocyanate compound is 60 to 100% by mass with respect to 100% by mass of the polyisocyanate (B).   The polyurethane resin composition according to claim 4, wherein the polyisocyanate (B) further contains a polynuclear body (B2) of an aromatic polyisocyanate compound.   The polyurethane resin composition according to claim 5, wherein the polyisocyanate (B) further contains a carbodiimide body (B3) of an aromatic polyisocyanate compound.   The total content of the polynuclear body (B2) of the aromatic polyisocyanate compound and the carbodiimide body (B3) of the aromatic polyisocyanate compound is 5 to 30% by mass with respect to 100% by mass of the polyisocyanate (B). The polyurethane resin composition according to claim 5 or 6. The polycarbonate polyol (A2) has the general formula (1):

[In General Formula (1): R ¹ is the same or different and represents an alkylene group having 3 to 8 carbon atoms. n shows the integer of 1-40. ]
The polyurethane resin composition in any one of Claims 1-7 which is a compound represented by these.   The polyurethane resin composition according to any one of claims 1 to 8, wherein the polyacryl polyol (A1) is a polyacryl polyol having a hydroxyl group at the end of the main chain.   The polyurethane resin composition according to any one of claims 1 to 9, which is used for sealing electric and electronic parts.   An electrical / electronic component sealed with the polyurethane resin composition according to claim 1.