JP2010106196A - Liquid polymer composition for potting housing material made of syndiotactic polystyrene, potting material and potting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid polymer composition for potting, having improved heat resistance, excellent adhesiveness to a syndiotactic polystyrene and sealability, a potting material for a housing material made of a syndiotactic polystyrene prepared by curing the composition and a method for potting a housing material made of a syndiotactic polystyrene. <P>SOLUTION: The liquid polymer composition for potting a housing material made of a syndiotactic polystyrene comprises a hydroxy group-containing liquid polyisoprene-based polymer hydride and a polyisocyanate compound, and if necessary, further a polyol compound except the polyol and/or a polyamine compound. The potting material is prepared by curing the liquid polymer composition. The method for potting a housing material made of syndiotactic polystyrene includes injecting the liquid polymer composition into components of electric or electronic material, industrial structural material, household electric appliances, etc., and curing the composition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid polymer composition for potting a syndiotactic polystyrene housing material, a potting material, and a potting method.

Syndiotactic polystyrene, which is a styrenic polymer having high syndiotacticity, and compositions in which other components are blended with this polymer have been reported in the patent literature (see Patent Literatures 1 to 3). The polystyrene having this syndiotactic structure, or a composition thereof, is superior in mechanical strength, heat resistance, solvent resistance, electrical properties, etc., compared to an atactic styrenic polymer or composition thereof. As a housing material for electrical and electronic parts such as connectors and printed circuit boards, it is used in the fields of industrial structural materials, automotive parts, and home appliances.
In such electrical / electronic parts, potting materials are used in order to protect the insulation around the contact member and prevent water from entering.
Since syndiotactic polystyrene has high heat resistance, it is often used in an environment where the periphery of the component becomes high temperature. In this case, since the potting material is also required to have high heat resistance, a general-purpose polyurethane potting material is inferior in heat resistance and cannot be used.
For this reason, silicone-based potting materials are often used as potting materials for electrical and electronic parts using syndiotactic polystyrene as a housing material (see Patent Documents 4 to 6).
However, since the adhesion between the syndiotactic polystyrene and the silicone-based potting material is low, it was necessary to improve the adhesion in advance by means such as modifying the surface of the syndiotactic polystyrene by ultraviolet irradiation.

Japanese Patent Laid-Open No. 62-104818 Japanese Patent Laid-Open No. 62-257948 JP-A-62-257950 Japanese Patent Publication No. 8-6039 Japanese Patent No. 2966257 Japanese Patent No. 3158903

  The present invention has been made in view of the above circumstances, and is a liquid polymer composition for potting having good heat resistance and excellent adhesion and sealing properties with syndiotactic polystyrene, and Shinji formed by curing the composition. It is an object of the present invention to provide a potting material for a housing material made of tactic polystyrene and a potting method for a housing material made of syndiotactic polystyrene.

As a result of intensive studies, the present inventors have found that the above problems can be achieved by using a hydride of a specific polyisoprene polymer and a polyisocyanate compound. The present invention has been completed based on such findings.
That is, the present invention includes the following.
1. A liquid polymer composition for potting a syndiotactic polystyrene housing material comprising a polyol compound comprising a hydride of a hydroxyl group-containing liquid polyisoprene polymer and a polyisocyanate compound.
2. 2. The liquid polymer composition for potting a syndiotactic polystyrene housing material according to 1 above, wherein the hydride has a number average molecular weight of 300 to 25000.
3. 3. The liquid polymer composition for potting a syndiotactic polystyrene housing material according to 1 or 2 above, wherein the hydrogenation rate of the hydride is 50% or more.
4). 2. The syndiotactic composition according to 1, further comprising 200 parts by mass or less of the polyol compound and / or the polyamine compound, relative to 100 parts by mass of the liquid polymer composition according to any one of 1 to 3 above. A liquid polymer composition for potting a polystyrene housing material.
5). 5. The liquid polymer composition for potting a syndiotactic polystyrene housing material according to 4 above, wherein the polyol compound is a low molecular weight polyol, a polymerization type polyol, or a castor oil-based polyol.
6). Furthermore, the liquid polymer composition for potting of the housing material made from a syndiotactic polystyrene according to any one of the above 1 to 5, further comprising an antioxidant, a catalyst, and an antifoaming agent.
7). A potting material for a housing material made of syndiotactic polystyrene obtained by curing the liquid polymer composition according to any one of 1 to 6 above.
8). 7. A potting method of a syndiotactic polystyrene housing material, wherein the liquid polymer composition according to any one of 1 to 6 is injected into an electric / electronic component and cured.

  According to the present invention, a liquid polymer composition for potting having good heat resistance and excellent adhesion and sealing properties with syndiotactic polystyrene, and a housing material made of syndiotactic polystyrene obtained by curing the composition Potting material and a method for potting a syndiotactic polystyrene housing material can be provided.

The present invention provides a liquid polymer composition for potting a syndiotactic polystyrene housing material comprising a polyol compound comprising a hydride of a hydroxyl group-containing liquid polyisoprene polymer and a polyisocyanate compound, and the liquid polymer composition. The present invention relates to a potting material for a housing material made of a syndiotactic polystyrene which is cured.
Hereinafter, the description will be made in sequence from the housing material made of syndiotactic polystyrene to the hydride of the hydroxyl group-containing liquid polyisoprene polymer used in the potting liquid polymer, the potting material, and the potting method.

[Syndiotactic polystyrene housing material]
The housing material which is the subject of the present invention includes syndiotactic polystyrene obtained by polymerizing a styrene monomer using a metallocene catalyst.
Here, the syndiotactic polystyrene has a degree of polymerization of 10 to 100,000, and its tacticity is 75% or more by dyad, preferably 85% or more, or 30% or more by pentad, preferably by ¹³ C-NMR. This refers to a styrene polymer having a syndiotactic structure of 50% or more.
Examples of the styrenic polymer include polystyrene, polyalkylstyrene, and polyhalogenated styrene. Further, the syndiotactic polystyrene used in the present invention is not necessarily a single polymer, and may be a mixture having different structures and molecular weights.
Using such syndiotactic polystyrene, the housing material is molded by various molding methods.

[Production Example of Hydroxyl-Containing Liquid Polyisoprene Polymer]
The hydroxyl group-containing liquid isoprene-based polymer used in the present invention is known or can be easily produced by a known method.
For example, an isoprene monomer is converted into hydrogen peroxide, an azo compound having a hydroxyl group (for example, 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide]), or a peroxide having a hydroxyl group (for example, Hydroxyl-containing liquid polyisoprene can be obtained by radical polymerization using cyclohexanone peroxide or the like) as a polymerization initiator.
The amount of the polymerization initiator used is, for example, about 1.0 to 50 g, preferably 2.0 to 30 g, 2,2′-azobis [2-methyl-N— (H ₂ O ₂₎ with respect to 100 g of isoprene monomer. 2-hydroxyethyl) propionamide] is about 5.0 to 100 g, preferably 10 to 50 g, and cyclohexanone peroxide is about 5.0 to 100 g, preferably 10 to 50 g.
Although the polymerization can be carried out without a solvent, it is preferable to use a solvent because of easy control of the reaction. As the solvent, ethanol, isopropanol, n-butanol or the like is used. The reaction temperature is about 80 to 150 ° C., preferably 100 to 140 ° C., the reaction time is about 0.5 to 15 hours, preferably 1 to 10 hours. It is.

Alternatively, a hydroxyl group-containing liquid polyisoprene can be obtained by anisotoprene monomer anion polymerization using a catalyst such as naphthalene dilithium to produce an isoprene living polymer and further reacting with a monoepoxy compound or the like.
Although the polymerization can be carried out without a solvent, it is preferable to use a solvent from the same viewpoint as in the case of radical polymerization. As the solvent, saturated hydrocarbons such as hexane and cyclohexane are used, the reaction temperature is about 50 to 100 ° C., preferably 70 to 100 ° C., the reaction time is about 1 to 10 hours, preferably 2 to 7 hours. . Further, at the time of polymerization, the addition polymerizable monomer having 2 to 22 carbon atoms (butene, pentene, styrene, α-methylstyrene, acrylonitrile, acrylic acid and its ester, methacrylic acid and its ester, chloride, in a proportion of 50 mol% or less with respect to isoprene Monomers such as vinyl, vinyl acetate, acrylamide, etc.) and diene monomers having 4 to 22 carbon atoms (butadiene, chloroprene, 1,3-pentadiene, cyclopentadiene, etc.) can also be added.
If the solution is distilled under reduced pressure after completion of the reaction, the solvent is removed, and a hydroxyl-containing liquid isoprene-based polymer is obtained.
The number average molecular weight of the hydroxyl group-containing liquid isoprene-based polymer is about 300 to 25,000, preferably 500 to 10,000, and the hydroxyl group content is 0.1 to 10 mol / kg, preferably 0.3 to 7 mol / kg. . Structurally, it is preferable that the total of the cis-1,4 structure and the trans-1,4 structure occupy 70% or more, and preferably 70 to 95%.
The hydroxyl group may be either at the end of the molecular chain or inside the molecular chain, but is preferably at the end of the molecular chain.
The hydroxyl group-containing liquid isoprene-based polymer is not limited to one type, and two or more types may be used.

[Production example of hydride of hydroxyl-containing liquid isoprene-based polymer]
Hydroxides of hydroxyl-containing liquid isoprene-based polymers are known or hydrogenate the hydroxyl-containing liquid isoprene-based polymers produced as described above by a known method using a homogeneous catalyst, a heterogeneous catalyst, or the like. Can be obtained.
In the case of using a homogeneous catalyst, the hydrogenation reaction is carried out using a saturated hydrocarbon such as hexane or cyclohexane or an aromatic hydrocarbon such as benzene, toluene or xylene as a solvent at a room temperature to about 150 ° C, preferably 50 to 150 ° C. at a reaction temperature, atmospheric pressure to 50 kg / cm ² G or so, is preferably carried out under a hydrogen pressure of 5~50kg / cm ² G.
As a homogeneous catalyst, a Ziegler catalyst or the like based on a combination of a transition metal halide and an alkylated product such as aluminum, alkaline earth metal or alkali metal is used, preferably about 0.01 to 0.1 mol% per double bond of the polymer, preferably 0.02-0.1 mol% is used. The reaction is usually completed in about 1 to 24 hours, preferably 1 to 10 hours.
On the other hand, when using a heterogeneous catalyst or the like, the hydrogenation reaction is carried out by using saturated hydrocarbons such as hexane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, ethers such as diethyl ether, THF and dioxane, ethanol, An alcohol such as isopropanol or a mixed system thereof is used as a solvent, and a reaction temperature of room temperature to about 200 ° C., preferably 50 to 190 ° C., normal pressure to about 100 kg / cm ² G, preferably 5 to 95 kg / cm. Performed under ² G hydrogen pressure.
As a heterogeneous catalyst, a catalyst such as nickel, cobalt, palladium, platinum, rhodium, ruthenium is used alone or supported on a support such as silica, diatomaceous earth, alumina, activated carbon, etc., and the amount used is based on the polymer weight. 0.05 to 10% by mass, preferably 1 to 10% by mass is appropriate. These catalysts may be used as a mixture. The reaction is usually completed in about 1 to 48 hours, preferably 1 to 24 hours.
If the catalyst is filtered off after completion of the reaction and the solution is distilled under reduced pressure, the solvent is removed and a hydride of a hydroxyl-containing liquid isoprene-based polymer is obtained.
The number average molecular weight of the hydride of this hydroxyl group-containing liquid isoprene-based polymer is about 300 to 25,000, preferably 500 to 10,000, and the hydroxyl group content is about 0.1 to 10 mol / kg, preferably 0.3 to 5 mol / kg. Is desirable.

The hydrogenation rate (hydrogenation rate) of the unsaturated double bond in the polymer after the hydrogenation reaction can be calculated by measuring the following bromine number.
Method for measuring bromine number (Japanese Industrial Standard (JIS K2605)): Dissolve a certain amount of sample in carbon tetrachloride and add methanol, acetic acid and sulfuric acid. This solution is kept at 0 ° C. to 5 ° C., and 0.5N potassium bromide-potassium bromate standard solution is added dropwise thereto for titration. The end point of titration is when the polarization current in the titration system suddenly changes due to free bromine, and this point is detected by a dead-stop electrotitrator. The value obtained is expressed as the mass of bromine that can be added per 100 g of sample.
By measuring the bromine number for the polymer before and after hydrogenation, it can be determined by the following equation.
Hydrogenation rate (%) = [(A−B) / A] × 100
Here, A: represents the bromine number of the polymer before hydrogenation, and B: represents the bromine number of the polymer after hydrogenation.
The hydrogenation rate of the polymer hydride used in the present invention is 50% or more, preferably 70% or more.
In the present invention, a hydride of two or more kinds of hydroxyl-containing liquid isoprene-based polymers may be mixed and used, or a hydroxyl-containing liquid isoprene-based polymer and a hydride may be mixed and used.
In order to obtain a cured product having good physical properties, the average number of hydroxyl groups per molecule of a hydride of a hydroxyl group-containing liquid isoprene-based polymer is preferably 1.7 or more, more preferably 2.0 or more.

[Other polyol compounds that can be used in combination]
In order to further improve the mechanical properties of the liquid polymer composition used in the present invention, a polyol compound other than the polyol compound described above (hereinafter also referred to as “other polyol compound”) may be used. Is possible. Here, the other polyol compound is a compound having two or more hydroxyl groups in one molecule.
Examples of other polyol compounds that can be used in combination include low molecular weight polyols, polymerization-type polyols, and castor oil-based polyols.
-Low molecular weight polyol As a low molecular weight polyol, you may use any of a primary polyol, a secondary polyol, and a tertiary polyol. Specifically, for example, 1,2-propylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 2,3- Pentanediol, 2,5-hexanediol, 2,4-hexanediol, 2-ethyl-1,3-hexanediol, cyclohexanediol, glycerin, N, N-bis-2-hydroxypropylaniline, N, N'- Examples thereof include low molecular weight polyols containing a hydroxyl group bonded to at least one secondary carbon, such as bishydroxyisopropyl-2-methylpiperazine and a propylene oxide adduct of bisphenol A.
Further, ethylene glycol, diethylene glycol, 1.3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, trimethylolpropane, which does not contain a hydroxyl group bonded to secondary carbon as a polyol. Pentaerythritol, dipentaerythritol and the like can also be used.
The molecular weight of the low molecular weight polyol is about 50 to 500, preferably 60 to 450.

-Polymerization type polyol The following polyol used as a polyurethane raw material can be used as a polymerization type polyol used for this invention in the range which does not impair the main point of this invention.
Polyether polyol and modified product thereof, polytetramethylene ether glycol, tetrahydrofuran / alkylene oxide copolymer polyol, epoxy resin-modified polyol, polyester polyol, trimethylol alkane partial transesterification product, polydiene polyol, and partially saponified ethylene Vinyl acetate copolymer.
The number average molecular weight of these polymerizable polyols is usually about 500 to 10,000, preferably 500 to 5,000.
Castor oil-based polyol Examples of the castor oil-based polyol that can be used in the present invention include castor oil, hydrogenated castor oil, and castor oil transesterification products.
As mentioned above, these polyol compounds can also be used in mixture of 2 or more types.

[Polyamine compound]
In the present invention, a polyamine compound may be used in addition to or in place of the other polyol compound. Here, the polyamine compound is a compound having an amino group having two or more active hydrogens in one molecule.
Specific examples of the polyamine compound include aliphatic polyamines such as hexamethylenediamine and polyoxypropylene polyamine, alicyclic polyamines such as 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane, and 3,3′-dichloro. Examples include aromatic polyamines such as -4,4'-diaminodiphenylmethane, 3,5'-diethyltoluene-2,4-diamine, and 3,5-diethyltoluene-2,6-diamine.

  The mixing ratio of these other polyol compounds and polyamine compounds is usually 200 parts by mass of the other polyol compounds and / or polyamine compounds with respect to 100 parts by mass of the hydride of the hydroxyl group-containing liquid isoprene-based polymer described above. Hereinafter, the ratio is preferably 100 parts by mass or less.

[Polyisocyanate compound]
The polyisocyanate compound used in the present invention is an organic compound having two or more isocyanate groups in one molecule, and these isocyanate groups are hydroxyl groups of the hydride of the hydroxyl group-containing liquid isoprene polymer. It has the reactivity with respect to.
Examples of the polyisocyanate compound include ordinary aromatic, aliphatic, and alicyclic compounds. Specifically, 4,4′-diphenylmethane diisocyanate, 2,2′-diphenylmethane diisocyanate, a mixture of 4,4′- and 2,2′-diphenylmethane diisocyanate (all MDI), tolylene diisocyanate (TDI), 1, 5-Naphthalene diisocyanate (NDI), carbodiimide-modified diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, p-phenylene diisocyanate (PPDI), naphthalene-1,5-diisocyanate, o-toluidine diisocyanate, triphenylmethane triisocyanate, tris (isocyanate phenyl) ) Aromatic polyisocyanates such as thiophosphate and isopropylbenzene-2,4-diisocyanate can be exemplified. Moreover, aliphatic-aromatic polyisocyanates such as xylylene diisocyanate (XDI) and tetramethylxylylene diisocyanate (TMXDI) (refers to polyisocyanates having no isocyanate group directly bonded to an aromatic ring in the molecule). Can be mentioned.

  Furthermore, hexamethylene diisocyanate, dodecane diisocyanate, lysine diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanate methyloctane, 1,3,6-hexamethylene triisocyanate, Aliphatic polyisocyanates such as trimethylhexamethylene diisocyanate, transcyclohexane-1,4-diisocyanate, bicycloheptane triisocyanate, isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (hydrogenated MDI), hydrogenated tolylene diisocyanate, hydrogenated xylylene Alicyclic polyisocyanates such as range isocyanate and hydrogenated tetramethylxylylene diisocyanate It can be mentioned titanate.

In addition, the cyclized trimer (isocyanurate-modified product) of the polyisocyanate compound, a burette-modified product, and ethylene glycol, 1,4-butanediol, propylene glycol, dipropylene glycol, trimethylolpropane, polyether polyol, Polymer polyol, polytetramethylene ether glycol, polyester polyol, acrylic polyol, hydrogenated dimer acid diisocyanate, polyalkadiene polyol, hydrogenated polyalkadiene polyol, partially saponified ethylene-vinyl acetate copolymer, castor oil-based polyol, etc. An addition reaction product of the polyol compound and the polyisocyanate compound can also be used.
These polyisocyanate compounds may be used as a mixture of two or more. Furthermore, the isocyanate groups of these polyisocyanate compounds may be phenols, oximes, imides, mercaptans, alcohols, ε-caprolactam, ethyleneimine. So-called blocked isocyanate compounds blocked with a blocking agent such as α-pyrrolidone, diethyl malonate, sodium hydrogen sulfite and boric acid can also be used.

[Viscosity modifier]
In the present invention, in order to adjust the viscosity of the liquid polymer composition, a hydride of 1-decene oligomer, paraffinic process oil, naphthenic process oil, olefin oligomer, alkylbenzene, alkylnaphthalene, alkyl as necessary. Viscosity modifiers such as diphenylethane, alkyldiphenyl, silicone oil, liquid paraffin, and paraffinic oligomers can be added.

[catalyst]
In this invention, in order to accelerate | stimulate reaction of the hydride of the said hydroxyl-containing liquid polyisoprene polymer and a polyisocyanate compound, a catalyst can be added as needed.
Catalysts that can be used are triethylenediamine, tetramethylguanidine, N, N, N ′, N′-tetramethylhexane-1,6-diamine, N, N, N ′, N ″, N ″ -penta. Tertiary amines such as methyldiethylenetriamine, bis (2-dimethylaminoethyl) ether, 1,2-dimethylimidazole, N-methyl-N ′-(2-dimethylamino) ethylpiperazine, diazabicycloundecene; Ate, Stanas laurate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin thiocarboxylate, dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin diacetate, dioctyltin markaptide, dioctyltin thiocarboxylate, phenylmercurypropionic acid Salt, octenoic acid Organometallic compounds and the like; and the like carboxylates of the tertiary amines.
The addition amount of the catalyst is 10 parts by mass at maximum and preferably 5 parts by mass with respect to 100 parts by mass of the hydride of the hydroxyl group-containing liquid polyisoprene polymer. When the amount exceeds 10 parts by mass, not only the curing acceleration effect reaches its peak, but also the risk of local abnormal reaction (gelation) increases, which is not preferable.

[Other additives]
In the present invention, for the purpose of improving heat resistance, weather resistance, etc., anti-aging agents such as hindered phenols, hindered amines, and benzotriazoles; antioxidants; ultraviolet absorbers; phosphorus compounds, halogen compounds, antimony oxides, etc. A flame retardant, an antifoaming agent such as a silicone compound, a foaming inhibitor such as zeolite and quicklime, and the like can be appropriately blended as desired.

[General production method of cured body]
In the present invention, the liquid polymer composition described above is cured to obtain a potting material for syndiotactic polystyrene. Next, the cured product will be described.
A liquid polymer composition is prepared by blending the various components described above at a predetermined ratio.
In preparing this composition, using a mixing device, a kneading device, etc., stirring at a temperature of about 0 to 120 ° C., preferably 15 to 100 ° C., for about 0.5 seconds to 8 hours, preferably 1 second to 5 hours. Mix.
As a method for preparing the composition, a method called a one-shot method or a method called a prepolymer method is usually used.
-One-shot method First, the component except a polyisocyanate compound is mix | blended among the compounding components, and it mixes by said temperature and time, and obtains a mixture. Next, the polyisocyanate compound and additive components not used in the previous mixing are added to the mixture, and the mixture is mixed at the above temperature and time to obtain a liquid polymer composition. At this time, when a compound having a hydroxyl group (—OH) and / or an amino group (—NH ₂ ) that reacts with the isocyanate group (—NCO) of the polyisocyanate compound is blended, the isocyanate group with respect to the hydroxyl group and amino group of the compound is mixed. A preferred ratio [—NCO / (— OH + —NH ₂ )] is 0.5 to 2.5, preferably 0.7 to 1.5 in terms of molar ratio.

・ Prepolymer method (1)
The equivalent ratio [—NCO / (— OH + —NH ₂ )] is in the range of 1.7 to 2.5, preferably 2.0 to 2.5, and the hydride of the hydroxyl group-containing liquid isoprene-based polymer composition ( A polyol compound, a polyamine compound and a desired component) and a polyisocyanate compound are reacted in the presence or absence of some or all of other additives to obtain a prepolymer. The reaction temperature is the same as described above, and the time is usually about 0.1 to 10 hours, preferably 0.5 to 8 hours. The remaining components are mixed with the prepolymer at the above temperature and time to obtain a liquid polymer composition. A preferred equivalent ratio [—NCO / (— OH + —NH ₂ )] at this time is 0.5 to 2.5, preferably 0.7 to 1.5.
・ Prepolymer method (2)
Equivalent ratio [—NCO / (— OH + —NH ₂ )] is in the range of 1.7 to 2.5, preferably 2.0 to 2.5. obtain. The reaction temperature is the same as above, and the time is usually about 0.1 to 10 hours, preferably 0.5 to 8 hours. This prepolymer is reacted with air humidity (water).

  The liquid polyisoprene polymer hydride composition prepared as described above is injected into an electrical / electronic component having a syndiotactic polystyrene as a housing and cured to obtain various types of potting materials. Can be given. Since the composition and the potting material obtained by curing the composition have significantly improved heat resistance and adhesiveness and sealability with syndiotactic polystyrene, the surface of syndiotactic polystyrene is previously exposed to ultraviolet rays as in the past. It is possible to eliminate the necessity of improving the adhesiveness by modification by irradiation or the like.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, evaluation of the present Example and the comparative example was performed by the following method.
[H-peel strength test]
As shown in FIG. 1, 50 mm × 50 mm syndiotactic polystyrene is arranged at 10 mm intervals, and a spacer is inserted between them so that a space of 10 mm × 10 mm × 50 mm is formed. The liquid polymer composition used in No. 2 was injected and cured at 80 ° C. for 15 hours to obtain a test piece.
The peel strength was measured using a tensile tester after curing the test piece at room temperature for 24 hours and after heating at 150 ° C. for 5 days. The tensile speed was 50 mm / min.

Examples 1-5, Comparative Example 1
Among the compositions shown in Table 1, raw materials excluding the polyisocyanate compound were blended, mixed and stirred at 60 ° C. for 2 hours, and cooled to 25 ° C. to obtain a liquid polymer. The polyisocyanate compound was added to this at the ratio shown in Table 1, and mixed and stirred at 25 ° C. for 2 minutes to obtain a liquid polymer composition. The evaluation results using this cured product are shown in Table 1.

Comparative Example 2
RTV silicone was cured at room temperature. The evaluation results are also shown in Table 1.

1) Epol (Idemitsu Kosan Co., Ltd .: number average molecular weight 2500, hydrogenation rate 98%, hydroxyl group content 0.90 mol / kg, cis 1,4 structure + trans 1,4 structure = 88%)
2) Death Module W (manufactured by Sumika Bayer Urethane Industry, dicyclohexylmethane diisocyanate)
3) Millionate MTL (Nippon Polyurethane, modified diphenylmethane diisocyanate)
4) OK All (Okabata Sangyo Co., Ltd.)
5) Poly bd R-45HT (manufactured by Idemitsu Kosan Co., Ltd., number average molecular weight 2800, hydroxyl group content 0.83 mol / kg, cis 1,4 structure + trans 1,4 structure = 80%)
6) Durasyn-128 (Ineos, α-olefin oligomer hydride)
7) TINUVIN B-75 (Ciba Japan, UV absorber, hindered amine)
8) Dibutyltin dilaurate 9) KS-66 (Shin-Etsu Silicone, silicone)
10) SE9187L (Toray Dow Corning)
11) Measurement not possible due to peeling after heating test

Table 1 shows the following.
-From Comparative Example 1, even if a hydroxyl group-containing liquid polybutadiene-based polymer is used as the polyol, if it is not hydrogenated, even if the initial sealing property is exhibited, if heated, it will peel off due to poor heat resistance. The sealing performance is completely lost.
-From the comparative example 2, in the potting of the silicone type conventionally used as a potting material, initial sealing property and the sealing property after a heating are not high compared with this invention.
-When Examples 1 and 2 are compared with Examples 3-5, especially the sealing property after a heating improves notably by mix | blending polyol type compounds other than the hydride of a hydroxyl-containing liquid polybutadiene type polymer.
From the above, it can be seen that the potting material for a housing material made of syndiotactic polystyrene provided by the present invention is a potting material excellent in heat resistance, adhesiveness and sealing property with syndiotactic polystyrene.

  According to the present invention, a liquid polymer composition for potting a housing material made of syndiotactic polystyrene, which is particularly excellent in heat resistance, adhesiveness and sealability with syndiotactic polystyrene, and potting formed by curing the same. Materials and potting methods are provided, so it is suitable for potting parts such as electrical and electronic materials (connectors, printed wiring, etc.), industrial structural materials, automobile parts, and household appliances that use syndiotactic polystyrene as a housing material. can do.

The H-type peeling test piece used by the Example and the comparative example is shown.

Claims (8)

  A liquid polymer composition for potting a syndiotactic polystyrene housing material, comprising a polyol compound comprising a hydride of a hydroxyl group-containing liquid polyisoprene polymer and a polyisocyanate compound.   2. The liquid polymer composition for potting a syndiotactic polystyrene housing material according to claim 1, wherein the hydride has a number average molecular weight of 300 to 25000.   3. The liquid polymer composition for potting a syndiotactic polystyrene housing material according to claim 1, wherein the hydrogenation rate of the hydride is 50% or more.   The liquid polymer composition according to any one of claims 1 to 3, further comprising 200 parts by mass or less of a polyol compound and / or a polyamine compound other than claim 1 with respect to 100 parts by mass of the liquid polymer composition according to any one of claims 1 to 3. A liquid polymer composition for potting a syndiotactic polystyrene housing material.   The liquid polymer composition for potting a syndiotactic polystyrene housing material according to claim 4, wherein the polyol compound is a low molecular weight polyol, a polymerization type polyol, or a castor oil-based polyol.   Furthermore, the liquid polymer composition for potting of the housing material made from a syndiotactic polystyrene according to any one of claims 1 to 5, further comprising an antioxidant, a catalyst, and an antifoaming agent.   A potting material for a housing material made of syndiotactic polystyrene obtained by curing the liquid polymer composition according to claim 1.   A method of potting a housing material made of syndiotactic polystyrene, wherein the liquid polymer composition according to claim 1 is injected into an electric / electronic component and cured.