Dispersant and resin composition

Abstract

Provided are: a dispersant comprising a polyether ester compound which suppresses elution of a metal and has excellent heat resistance, while reducing the viscosity of a resin composition by satisfactorily dispersing an inorganic powder in a resin; and a resin composition comprising the dispersant. The dispersant is composed of a polyether ester compound represented by formula (1). (In formula (1), R1 represents a hydrocarbon group having 1-22 carbon atoms, AO represents an oxyalkylene group having 2-4 carbon atoms, n represents the average number of moles of the oxyalkylene group added and is a number of 1-60, R2 represents a phenolic hydroxyl group, and m represents a number of 2-3. )

Description

TECHNICAL FIELD

[0001] The present application relates to a dispersant composed of a polyether ester compound and a resin composition containing the same. BACKGROUND

[0002] The polyether ester compound can control its polarity, viscosity, reactivity, etc. by adjusting the kind of oxyalkylene group contained as a constituting unit, its polymerization degree, thereby imparting softness, steric repulsion, etc. properties, and is used for various purposes such as a detergent composition, a water treatment agent, a scale inhibitor, a lubricant, a plasticizer, a dispersant, etc.

[0003] Among the dispersants in these uses, an ester compound of a polyether and an aromatic carboxylic acid, a phosphoric acid is proposed, and the polyether ester compound is used to exhibit steric repulsion properties in solvents, resins. In addition, the dispersant disperses inorganic powders, etc. in solvents, and thus is used in various industrial fields. As the inorganic powders, for example, ceramic, metal powders can be cited, and a composition containing the inorganic powders is used for a dielectric layer of a multilayer ceramic capacitor, a semiconductor substrate, a sensor, an electronic component such as a liquid crystal display element, etc.

[0004] However, a semiconductor encapsulating material (hereinafter sometimes referred to simply as "encapsulating material") is used to protect a semiconductor wafer from heat, ultraviolet rays, moisture, impact, etc., and is composed of a resin composition containing a thermosetting resin that ensures electrical insulation, and an inorganic filler such as alumina dispersed in a thermosetting resin such as an epoxy resin. The inorganic filler such as alumina commonly used in the semiconductor encapsulating material has poor dispersibility in the epoxy resin, and becomes a cause of an increase in the viscosity of the encapsulating material. When the viscosity of the encapsulating material is high, sometimes filling failure of the encapsulating material occurs in the encapsulating process, and thus reducing the viscosity of the encapsulating material is an important issue. Therefore, it is reported in Patent Literature 1 that the dispersibility of the filler is improved by modifying the surface of a silica filler with a silane coupling agent, and thus the viscosity of the encapsulating material is reduced.

[0005] On the other hand, in recent years, the microparticulation of the filler is continuously progressing, and it is difficult to sufficiently modify the surface of the filler with the silane coupling agent, and thus the improvement of the dispersibility of the silane coupling agent is limited. Therefore, it is reported in Patent Literature 2 that the dispersibility of the filler is improved by using a dispersant containing a salt of at least one of an acidic phosphoric acid chain ester and an acidic phosphorous acid chain ester and a polyamine, and thus the viscosity of the encapsulating material is reduced.

[0006] However, due to further microparticulation and high concentration of the filler in recent years, the amount of the dispersant required to improve the dispersibility of the filler increases, and in the case where encapsulation is performed using an encapsulating material using the dispersant described in Patent Literature 2, there is a risk that acidic functional groups of the acidic phosphoric acid chain ester and the acidic phosphorous acid chain ester from the dispersant will cause metal constituting a wiring on a substrate to be eluted to cause migration and result in short circuit, and the moisture resistance reliability of a semiconductor device will be reduced.

[0007] Patent Literature 3 reports that the moisture resistance reliability is improved by using a dispersant having a basic functional group and a silane coupling agent in combination, but as described above, the dispersibility of the silane coupling agent is limited, and it is difficult to balance the reduction in viscosity and the improvement in reliability.

[0008] In addition, in recent years, the market for power semiconductors capable of handling higher voltages and larger currents than ever before is expanding, but the packaging material for power semiconductors having a higher operating temperature than ever before requires high heat resistance, and in the case where the heat resistance of an additive used in the packaging material is low, the high-temperature reliability of the semiconductor device can be reduced.

[0009] Thus, in semiconductor packaging materials, in addition to the requirement that inorganic fillers such as fillers are well dispersed in thermosetting resins, it is also required to suppress the elution of metals and to have good heat resistance. This is not limited to semiconductor packaging materials, and is sometimes similarly required in the above-described various electronic components.

[0010] Prior Art Documents

[0011] Patent Literature

[0012] Patent Literature 1: Japanese Patent Application Laid-Open (JP A) No. 2021-55108

[0013] Patent Literature 2: Japanese Patent Application Laid-Open (JP A) No. 2022-7782

[0014] Patent Literature 3: Japanese Patent Application Laid-Open (JP A) No. 2021-24945 SUMMARY

[0015] The present application was completed in view of the above-described actual situations, and the problem to be solved is to provide a dispersant composed of a polyether ester compound, which disperses inorganic fillers well in a resin, reduces the viscosity of the resin composition, suppresses the elution of metals, and has excellent heat resistance, and a resin composition containing the same.

[0016] The present inventors and others have conducted intensive studies in order to solve the above-described problems, and as a result, it has been found that the above-described problems can be solved by using a polyether ester compound having a specific structure. That is, the present application relates to the following [1], [2].

[0017] [1] A dispersant composed of a polyether ester compound represented by the following formula (1).

[0018]

[0019] (In formula (1), R 1 is a hydrocarbon group having 1 to 22 carbon atoms, AO is an oxyalkylene group having 2 to 4 carbon atoms, n is the average addition mole number of the oxyalkylene group, is a number of 1 to 60, and R 2is a phenolic hydroxyl group, and m is a number of 2 to 3.

[0020] [2] A resin composition comprising an inorganic powder, a resin, and the dispersant described in the above [1], the inorganic powder being dispersed in the resin, and comprising 0.1 to 50 parts by mass of the dispersant with respect to 100 parts by mass of the inorganic powder.

[0021] According to the present application, it is possible to provide a dispersant composed of a polyether ester compound, which allows good dispersion of an inorganic powder in a resin, reduces the viscosity of a resin composition, suppresses the elution of metal, and is excellent in heat resistance, and a resin composition comprising the dispersant. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a graph of a H NMR spectrum of a polyether ester compound 1 (a compound represented by the structural formula in Figure 1 1 DETAILED DESCRIPTION

[0023] Hereinafter, the embodiments of the present application will be described in order.

[0024] (Polyether ester compound)

[0025] The polyether ester compound used in the dispersant of the embodiment of the present application is a compound represented by the following formula (1).

[0026]

[0027] (In formula (1), R 1 is a hydrocarbon group having 1 to 22 carbon atoms, AO is an oxyalkylene group having 2 to 4 carbon atoms, n is the average addition mole number of the oxyalkylene group, and is a number of 1 to 60, and R 2 is a phenolic hydroxyl group, and m is a number of 2 to 3.

[0028] In formula (1), R 1 ​​The hydrocarbon group having 1 to 22 carbon atoms can be straight-chain or branched, and examples thereof include straight-chain saturated hydrocarbon groups such as methyl, ethyl, propyl, butyl, hexyl, heptyl, octyl, lauryl, myristyl, palmitostyl, stearyl, behenyl, 1-dodecyl, branched saturated hydrocarbon groups such as isopropyl, isobutyl, tert-butyl, isopentyl, isooctyl, 2-ethylhexyl, isononyl, 3,5,5-trimethylhexyl, isodecyl, isostearyl, 2-octyldecyl, 2-octyldodecyl, 2-hexyldecyl, unsaturated hydrocarbon groups such as allyl, (meth)acryl, palmitoyl, oleyl, linoleyl, and the like. One or two or more of these can be used in combination. From the viewpoint of dispersibility, a straight-chain or branched saturated hydrocarbon group having 4 to 18 carbon atoms or an unsaturated hydrocarbon group is preferred, and a straight-chain or branched saturated hydrocarbon group having 4 to 18 carbon atoms is further preferred.

[0029] In formula (1), AO is an oxyalkylene group having 2 to 4 carbon atoms, and the form of AO can be straight-chain or branched. However, when the number of carbon atoms is 3 to 4, the branched form is preferred. In addition, AO can be one or two or more, and when two or more, the addition form can be random or block. However, from the viewpoint of dispersibility, the block form is preferred.

[0030] Examples of AO include oxyethylene (EO), oxypropylene (PO), oxybutylene (BO), and the like. From the viewpoint of dispersibility, one or two selected from oxyethylene and oxypropylene is preferred, and oxyethylene and oxypropylene are more preferred. When two or more of AO are used in combination, the ratio can be appropriately determined depending on the kind of AO, and the like. For example, when EO is combined with PO or BO, the composition ratio of EO to PO or BO is preferably EO: PO (or BO) = 10:90 to 90:10 in terms of molar fraction (mol%), and more preferably 20:80 to 80:20.

[0031] In formula (1), n is the average addition mole number of the oxyalkylene group, and is a number from 1 to 60. n can be appropriately set depending on the kind of AO, and the like, but from the viewpoint of dispersibility, a number from 5 to 40 is preferred, a number from 5 to 30 is more preferred, and a number from 10 to 30 is further preferred.

[0032] In formula (1), R 2 represents a phenolic hydroxyl group, that is, -OH directly bonded to the benzene ring in formula (1). m represents the number of phenolic hydroxyl groups, and is a number from 2 to 3. The phenolic hydroxyl group in the polyether ester compound functions as a site for adsorbing inorganic powder. The more the number of phenolic hydroxyl groups, the more easily the inorganic powder is adsorbed, and thus from the viewpoint of dispersibility, m = 3 is preferred.

[0033] Next, an embodiment of the method for producing the polyether ester compound represented by formula (1) will be described.

[0034] The polyether ester compound represented by Formula (1) can be obtained, for example, by a production method including a first step of producing a polyether, and a second step of reacting the polyether obtained in the first step with an aromatic carboxylic acid having a phenolic hydroxyl group.

[0035] The first step will be described.

[0036] The polyether can be produced, for example, by adding an alkylene oxide to an alcohol having a linear or branched hydrocarbon group having 1 to 22 carbon atoms.

[0037] As the catalyst used in the addition reaction of the alkylene oxide, an alkali catalyst can be mentioned, and for example, an alkali metal, an alkaline earth metal, an oxide, a hydroxide, an alkoxide, an alkylamine such as triethylamine, and a alkanolamine such as triethanolamine can be used. In addition to the above-mentioned alkali catalyst, a Lewis acid catalyst such as boron trifluoride and tin tetrachloride can also be used. The amount of the catalyst used is usually 0.01 to 5.0% by mass with respect to the mass after the addition reaction is completed.

[0038] The addition reaction of the alkylene oxide can be performed by adding the alkylene oxide continuously while pressurizing under an atmosphere of a non-reactive gas such as argon or nitrogen at 50 to 200°C and 0.02 to 1.0 MPa.

[0039] After the addition reaction is completed, the pH of the reaction product is adjusted to about 6 to 7 at normal pressure and normal temperature, as necessary, and the moisture generated during the addition reaction is removed. The removal of the moisture can be performed by a conventional method, and for example, can be performed at 80 to 120°C under reduced pressure. In addition, the salt contained in the reaction product is removed, as necessary. The removal of the salt can be performed, for example, by filtration or the like.

[0040] Next, the second step will be described. In the second step, the polyether obtained in the first step is reacted with the above-mentioned prescribed aromatic carboxylic acid, as described above.

[0041] As the aromatic carboxylic acid having a phenolic hydroxyl group used in the second step, for example, 2,4-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, and gallic acid can be mentioned.

[0042] The reaction conditions can be appropriately determined depending on the polyether used, the above-mentioned prescribed aromatic carboxylic acid, and the like, but the reaction temperature is usually 60 to 150°C, preferably 70 to 140°C, and further preferably 80 to 130°C. In addition, the reaction can be performed under reduced pressure, and for example, can be performed at -0.10 to -0.01 MPa (gauge pressure).

[0043] A catalyst can be used in the second step. As the catalyst, an acid catalyst such as p-toluenesulfonic acid, methanesulfonic acid can be given. The amount of the catalyst used is usually 1.0 to 5.0% by mass relative to the polyether.

[0044] After the reaction, the pH of the reaction product is adjusted to about 5 to 6 at normal pressure and normal temperature as needed, and the water generated during the reaction is removed. The removal of the water can be performed by a conventional method, for example, under reduced pressure at 80 to 120°C. In addition, the salt contained in the reaction product is removed as needed. The removal of the salt can be performed by filtration or the like, for example.

[0045] The reaction of the first step and the reaction of the second step can be performed in the absence of a solvent or in a suitable dehydrating organic solvent. The solvent used in the reaction can be removed by distillation or the like after the reaction.

[0046] (Dispersant)

[0047] The dispersant of the embodiment of the present application is composed of the above polyether ester compound. That is, the dispersant contains the above polyether ester compound as an effective ingredient for dispersing a desired inorganic powder such as a filler in a desired medium such as a resin, and can be composed of the polyether ester compound alone or composed of the compound and other additives that do not hinder the function of the compound, but is preferably composed of the polyether ester compound alone. As such additives, a surfactant, an antioxidant, or the like can be given. The content of the additives can be appropriately determined.

[0048] (Resin composition)

[0049] The resin composition of the embodiment of the present application contains a resin, an inorganic powder, and the above dispersant. Furthermore, the inorganic powder is dispersed in the resin. It is considered that the above polyether ester compound that constitutes the dispersant contributes to the dispersibility, preferably uniform dispersibility, of the inorganic powder in the resin.

[0050] The content of the dispersant can be appropriately determined depending on the kind of the above polyether ester compound contained in the inorganic powder and the dispersant, but it is preferable that 0.1 to 50% by mass of the dispersant be contained as the above polyether ester compound relative to 100% by mass of the inorganic powder.

[0051] The inorganic powder that can be used can be appropriately selected depending on the use or the like, and ceramic powders such as alumina, fused silica, and titanium oxide, metal powders such as silver, copper, and nickel, and carbon powders such as carbon black and carbon nanotube can be given. In the case of a semiconductor packaging use, ceramic powders such as alumina and fused silica are used as inorganic fillers. The content of the inorganic powder is preferably 60 to 98% by mass in the entire resin composition.

[0052] The resin that can be used can be appropriately selected depending on the use or the like. Examples thereof include epoxy resins, acrylic resins, butyral resins, polyimide resins, and the like, and an epoxy resin is preferred. As the epoxy resin, examples include bisphenol A type epoxy resins, bisphenol F type epoxy resins, biphenyl type epoxy resins, biphenyl aralkyl epoxy resins, and the like. The content of the resin is preferably 10 to 50 parts by mass relative to 100 parts by mass of the inorganic powder.

[0053] In the resin composition of the embodiment, other additives can be contained in addition to the above-described components, within a range not hindering the functions of the resin, the dispersant, and the inorganic powder. As such an additive, examples include curing agents, curing accelerators, antioxidants, flame retardants, colorants, plasticizers, and the like.

[0054] As the curing agent when an epoxy resin is used as the resin, examples include phenol aldehyde resins such as a biphenyl novolak type phenol aldehyde resin, amines such as ethylenediamine, and acid anhydrides such as trimellitic anhydride.

[0055] The properties of the resin composition are appropriately determined depending on the composition of the contained components, but are generally a paste.

[0056] The resin composition of the embodiment can be produced by a publicly known method. Examples thereof include a method in which the dispersant, the resin, the inorganic powder, and an additive added as necessary are added to a container, and then a dispersion treatment is performed at room temperature or under heating. The order of addition of the components is not particularly limited. As a dispersing device used for the dispersion treatment, a publicly known disperser can be used. Examples thereof include roll mills, ball mills, bead mills, sand mills, homogenizers, dispersers, self-rotation and revolution type mixers, and the like.

[0057] The resin composition contains the above-described polyether ester compound as an effective component of the dispersant, and thus, for example, when used as a semiconductor packaging material, (i) the inorganic powder such as an inorganic filler is well dispersed in the resin, and the increase in the viscosity of the resin composition can be well suppressed, and (ii) by the excellent metal low elution property and heat resistance of the polyether ester compound, the decrease in the moisture resistance reliability and the high temperature reliability of the semiconductor device due to the elution of metal from the wiring on the substrate can be well suppressed. Thus, the resin composition is suitable as a semiconductor packaging material. Note that the dispersibility of the inorganic powder such as an inorganic filler in the resin, the elution property of the dispersant with respect to metal such as copper, and the heat resistance thereof can be evaluated, for example, by the method described in the column of Examples below.

[0058] Examples

[0059] Next, the embodiment of the present application is further explained in detail based on Examples.

[0060] (Identification of polyether ester compounds 1 to 8)

[0061] The identification of the polyether ester compounds 1 to 8 obtained in Examples 1 to 6 and Comparative Examples 1 and 2 described later was performed using proton nuclear magnetic resonance spectroscopy (1H NMR). 1 The measurement conditions of 1H NMR are shown below. 1 The measurement conditions of 1H NMR are shown below.

[0062] Apparatus: JNM-ECA-600 manufactured by JEOL Ltd.

[0063] Solvent: deuterated dimethyl sulfoxide

[0064] Temperature: 25°C

[0065] Frequency: 400 MHz

[0066] Cumulative number: 64

[0067] (Example 1: Synthesis of polyether ester compound 1)

[0068] Into a 5-liter capacity pressure-resistant vessel made of stainless steel equipped with a stirrer, a pressure gauge, a thermometer, a safety valve, a gas inlet tube, a gas outlet tube, a cooling coil, and a vapor jacket, 288 g (2 mol) of 3, 5, 5-trimethyl-l-hexanol (trade name: NONANOL, manufactured by KHNEO CHEM CO., LTD.) and 6 g of potassium hydroxide were charged, and after nitrogen substitution, the temperature was raised to 120°C while stirring. Under stirring, 581 g (10 mol) of propylene oxide was added from another prepared pressure-resistant vessel through the gas inlet tube while pressurizing with nitrogen at 120°C and 0.05 to 0.50 MPa (gauge pressure). After the completion of the addition, the reaction was performed under the same conditions until the internal pressure became constant. Subsequently, 1057 g (24 mol) of ethylene oxide was added by the above method, and after the completion of the addition, the reaction was performed under the same conditions until the internal pressure became constant. Then, the reaction product was taken out of the pressure-resistant vessel, neutralized with hydrochloric acid to make pH 6 to 7, and subjected to a 1-hour reduced pressure treatment at 100°C in order to remove the contained water, and finally, the salt was removed by filtration to obtain a polyether (first step).

[0069] Next, into a 0.5-liter capacity reaction vessel made of glass equipped with a stirring device, a thermometer, and a gas inlet tube, 250 g (0.26 mol) of the polyether obtained in the first step and 47.7 g (0.22 mol) of gallic acid monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.), and 6.2 g (0.065 mol) of methanesulfonic acid were charged, and the reaction was performed under a reduced pressure condition of -0.08 MPa (gauge pressure) or less and at 120°C for 10 hours. The reaction product was neutralized with sodium bicarbonate to make pH 5 to 6, and subjected to a 1-hour reduced pressure treatment at 100°C in order to remove the contained water, and finally, the salt was removed by filtration to obtain a polyether ester compound 1 (second step).

[0070] The obtained polyether ester compound 1 was identified by the above-mentioned measuring method. It was confirmed from the spectrum shown in Fig. 1 that the polyether ester compound 1 was a polyether ester compound represented by the formula (1) having the constitution shown in Table 1, based on the peak of A (δ 0.87 ppm), the peak of B (δ 1.03 ppm), the peak of C (δ 1.22 ppm), the peak of D (δ 1.33 ppm), the peak of E (δ 1.45 ppm), the peak of F (δ 3.15 to 3.71 ppm), the peak of G (δ 4.27 ppm), and the peak of H (δ 6.95 ppm). The polyether ester compound 1 was used as a dispersant 1 for the evaluation described later. Figure 1

[0071] (Example 2: Synthesis of polyether ester compound 2)

[0072] For the first step, the amount of propylene oxide was made 1569 g (27 mol), the amount of ethylene oxide was made 1188 g (27 mol), and otherwise, the polyether was obtained in the same manner as in Example 1.

[0073] Next, to a glass-made reaction vessel of 0.5 liter capacity equipped with a stirring device, a thermometer, and a gas blowing tube, the polyether obtained in the above-mentioned first step, 250 g (0.16 mol), and gallic acid monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.), 25.7 g (0.14 mol), and methanesulfonic acid, 3.9 g (0.041 mol), were charged, and the reaction was carried out under a reduced pressure of -0.08 MPa (gauge pressure) or less at 120°C for 10 hours. The reaction mixture was neutralized with sodium bicarbonate to make the pH 5 to 6, and a reduced pressure treatment was carried out at 100°C for 1 hour to remove water, and finally, the salt was removed by filtration to obtain a polyether ester compound 2 (the above is the second step). The polyether ester compound 2 was identified in the same manner as in the case of Example 1, and as a result, it was confirmed that the polyether ester compound 2 was a polyether ester compound represented by the formula (1) having the constitution shown in Table 1. The polyether ester compound 2 was used as a dispersant 2 for the evaluation described later.

[0074] (Example 3: Synthesis of polyether ester compound 3)

[0075] ​Into a 5 liter capacity pressure vessel made of stainless steel equipped with a stirrer, a pressure gauge, a thermometer, a safety valve, a gas inlet tube, a gas outlet tube, a cooling coil and a vapor jacket, 288 g (2 mol) of 3,5,5-trimethyl-l-hexanol (trade name: NONANOL, manufactured by KHNEOCHEM CO., LTD.) and 6 g of potassium hydroxide were charged, and after nitrogen substitution, the temperature was raised to 120°C while stirring. Under stirring, 1408 g (32 mol) of ethylene oxide was added from another prepared pressure vessel at 120°C and 0.05 to 0.50 MPa (gauge pressure), and after the addition was completed, the reaction was carried out under the same conditions until the internal pressure became constant. Then, the reaction product was taken out of the pressure vessel, neutralized with hydrochloric acid to make pH 6 to 7, and in order to remove the contained water, a reduced pressure treatment was carried out at 100°C for 1 hour, and finally, the salt was removed by filtration to obtain a polyether (the above is the first step).

[0076] Next, into a 0.5 liter capacity reaction vessel made of glass equipped with a stirrer, a thermometer and a gas inlet tube, 250 g (0.29 mol) of the polyether obtained in the above first step and 46.2 g (0.25 mol) of gallic acid monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.), 7.1 g (0.074 mol) of methanesulfonic acid were charged, and the reaction was carried out under reduced pressure of -0.08 MPa (gauge pressure) or less at 120°C for 10 hours. The reaction product was neutralized with sodium bicarbonate to make pH 5 to 6, and in order to remove the contained water, a reduced pressure treatment was carried out at 100°C for 1 hour, and finally, the salt was removed by filtration to obtain a polyether ester compound 3 (the above is the second step). The same identification as in the case of Example 1 was carried out, and as a result, it was confirmed that the polyether ester compound 3 was a polyether ester compound represented by the formula (1), and the composition thereof was as shown in Table 1. The polyether ester compound 3 was used as a dispersant 3 in the evaluation described later.

[0077] (Example 4: Synthesis of polyether ester compound 4)

[0078] As to the first step, 3,5,5-trimethyl-l-hexanol (trade name: NONANOL, manufactured by KHNEOCHEM CO., LTD.) 288 g (2 mol) was replaced by isodecyl alcohol 316.6 g (2 mol), and otherwise, the same as in Example 3 to obtain a polyether.

[0079] Next, a glass-made reaction vessel of 0.5 liter capacity equipped with a stirring device, a thermometer, and a gas blowing tube was charged with the polyether obtained in the first step above, 250 g (0.29 mol), gallic acid monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.), 45.4 g (0.24 mol), and methanesulfonic acid, 6.9 g (0.072 mol), and the mixture was reacted under reduced pressure of -0.08 MPa (gauge pressure) or less at 120°C for 10 hours. The reaction mixture was neutralized with sodium bicarbonate to make the pH 5 to 6, and the moisture content was removed by reduced pressure treatment at 100°C for 1 hour. Finally, the salt was removed by filtration to obtain 300 g of the polyether ester compound 4 (the second step above). The polyether ester compound 4 was identified in the same manner as in the case of Example 1, and as a result, it was confirmed that the polyether ester compound 4 was a polyether ester compound represented by the formula (1), and the composition thereof was as shown in Table 1. The polyether ester compound 4 was used as a dispersant 4 in the evaluation described later.

[0080] (Synthesis of polyether ester compound 5 (Example 5))

[0081] As the first step, a polyether was obtained in the same manner as in Example 1.

[0082] Next, a glass-made reaction vessel of 0.5 liter capacity equipped with a stirring device, a thermometer, and a gas blowing tube was charged with the polyether obtained in the first step above, 250 g (0.29 mol), gallic acid monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.), 45.4 g (0.24 mol), and methanesulfonic acid, 6.9 g (0.072 mol), and the mixture was reacted under reduced pressure of -0.08 MPa (gauge pressure) or less at 120°C for 10 hours. The reaction mixture was neutralized with sodium bicarbonate to make the pH 5 to 6, and the moisture content was removed by reduced pressure treatment at 100°C for 1 hour. Finally, the salt was removed by filtration to obtain 300 g of the polyether ester compound 4 (the second step above). The polyether ester compound 4 was identified in the same manner as in the case of Example 1, and as a result, it was confirmed that the polyether ester compound 4 was a polyether ester compound represented by the formula (1), and the composition thereof was as shown in Table 1. The polyether ester compound 4 was used as a dispersant 4 in the evaluation described later.

[0083] (Synthesis of polyether ester compound 6 (Example 6))

[0084] As the first step, 3,5,5-trimethyl-l-hexanol (trade name: NONANOL, manufactured by KH NEOCHEM CO., LTD.), 288 g (2 mol) was replaced with 1-dodecanol, 372.7 g (2 mol), and a polyether was obtained in the same manner as in Example 1.

[0085] Next, a glass-made reaction vessel of 0.5 liter capacity equipped with a stirring device, a thermometer, and a gas blowing tube was charged with the polyether obtained in the above first step, 250 g (0.25 mol), gallic acid monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.), 39.0 g (0.21 mol), and methanesulfonic acid, 6.0 g (0.062 mol), and the mixture was reacted under reduced pressure of -0.08 MPa (gauge pressure) or less at 120°C for 10 hours. The reaction mixture was neutralized with sodium bicarbonate to make the pH 5 to 6, and the moisture content was removed by reduced pressure treatment at 100°C for 1 hour. Finally, the salt was removed by filtration to obtain a polyether ester compound 6 (the above is the second step). The polyether ester compound 6 was identified in the same manner as in the case of Example 1, and as a result, it was confirmed that the polyether ester compound 6 was a polyether ester compound represented by the formula (1), and the composition thereof was as shown in Table 1. The polyether ester compound 6 was used as a dispersant 6 in the evaluation described later.

[0086] (Synthesis of polyether ester compound 7 (Comparative Example 1))

[0087] The polyether was obtained in the same manner as in Example 1 for the first step.

[0088] Next, a glass-made reaction vessel of 0.5 liter capacity equipped with a stirring device, a thermometer, and a gas blowing tube was charged with the polyether obtained in the above first step, 250 g (0.25 mol), gallic acid monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.), 39.0 g (0.21 mol), and methanesulfonic acid, 6.0 g (0.062 mol), and the mixture was reacted under reduced pressure of -0.08 MPa (gauge pressure) or less at 120°C for 10 hours. The reaction mixture was neutralized with sodium bicarbonate to make the pH 5 to 6, and the moisture content was removed by reduced pressure treatment at 100°C for 1 hour. Finally, the salt was removed by filtration to obtain a polyether ester compound 6 (the above is the second step). The polyether ester compound 6 was identified in the same manner as in the case of Example 1, and as a result, it was confirmed that the polyether ester compound 6 was a polyether ester compound represented by the formula (1), and the composition thereof was as shown in Table 1. The polyether ester compound 6 was used as a dispersant 6 in the evaluation described later.

[0089] (Synthesis of polyether ester compound 8 (Comparative Example 2))

[0090] The polyether was obtained in the same manner as in Example 2 for the first step.

[0091] Next, a glass-made 0.5 liter capacity reaction vessel equipped with a stirring device, a thermometer, and a gas blowing tube was charged with the polyether obtained in the first step 250 g (0.16 mol) and phthalic anhydride (manufactured by Kanto Chemical Co., Inc.) 24.3 g (0.16 mol), and the mixture was reacted at 120°C for 4 hours. It was confirmed by acid value measurement that 98% or more of the anhydride had been half-esterified, and the reaction was completed. Thus, polyether ester compound 8 was obtained. As in the case of Example 1, it was confirmed that the polyether ester compound 8 was a compound represented by the following formula (2). The polyether ester compound 8 was used as dispersant 8 in the evaluation described later.

[0092]

[0093] (Dispersibility Evaluation)

[0094] Each of the polyether ester compounds (dispersants) 1 to 8 obtained in Examples 1 to 6 and Comparative Examples 1 and 2 was used to prepare a resin composition as follows. 2 g of inorganic powder (alumina, manufactured by Resonac Corporation., trade name: AL-43-L), 0.494 g of an epoxy resin (manufactured by Nippon Kayaku Co., Ltd., trade name: NC-3000-L) as a resin, 0.363 g of a phenol aldehyde resin (manufactured by Nippon Kayaku Co., Ltd., trade name: KAYAHARD GPH-65) as a curing agent, and 0.02 g of the dispersant were weighed into a 50 mL screw tube, and kneaded using a doctor blade in an oil bath at 100°C. The viscosity of the obtained resin composition was measured at a temperature of 90°C and a shear rate of 1 (1 / s) using a dynamic viscoelasticity device (Paar Physica MCR-300, manufactured by Anton Paar). The measurement results were evaluated according to the following criteria.

[0095] ◎: Shear viscosity was less than 200 Pa-s

[0096] O: Shear viscosity was 200 Pa-s or more and less than 500 Pa-s

[0097] X: Shear viscosity was 500 Pa-s or more

[0098] (Copper Elution Evaluation)

[0099] A 10% (isopropyl alcohol / water) solution of each of the polyether ester compounds (dispersants) 1 to 8 obtained in Examples 1 to 6 and Comparative Examples 1 and 2 was prepared, and a copper plate cut to 1 x 2 cm was immersed therein and left to stand at 80°C for 18 hours. The copper plate was taken out and washed, and the weight was measured. The amount of eluted copper was calculated from [(weight of the copper plate before immersion) - (weight of the copper plate after immersion)] / (weight of the copper plate before immersion) x 100, and evaluated according to the following criteria.

[0100] ◎: Dissolution amount less than 0.15%

[0101] O: Dissolution amount 0.15% or more and less than 0.3%

[0102] X: Dissolution amount 0.3% or more

[0103] (Heat resistance evaluation)

[0104] For each of the polyether ester compounds (dispersants) 1 to 8 obtained in Examples 1 to 6 and Comparative Examples 1 and 2, the weight reduction ratio at the time of keeping at 200°C for 2 hours under air was measured in a thermogravimetric measurement (TG) measurement. The weight reduction ratio was calculated by (weight reduction amount (g) / initial weight (g)) x 100, and evaluated in accordance with the following criteria.

[0105] ◎: Weight reduction ratio less than 15%

[0106] O: Weight reduction ratio 15% or more and less than 30%

[0107] X: Weight reduction ratio 30% or more

[0108] Each of the evaluation results is shown in Table 2. In Table 2, the column on the upper side of each evaluation item indicates the measured value, and each unit thereof is as described above.

[0109] [Table 1]

[0110]

[0111] [Table 2]

[0112]

[0113] It was found that the dispersants 1 to 6 composed of the polyether ester compounds 1 to 6 obtained in Examples 1 to 6 were excellent in copper low dissolution and heat resistance, and reduced the shear viscosity of the resin composition as compared with the case where the dispersant 7 composed of the polyether ester compound 7 of Comparative Example 1 was used.

[0114] On the other hand, the dispersant 7 composed of the polyether ester compound 7 obtained in Comparative Example 1 was excellent in copper low dissolution and heat resistance, but had a small effect of reducing the shear viscosity of the resin composition. In addition, the dispersant 8 composed of the polyether ester compound 8 obtained in Comparative Example 2 reduced the shear viscosity of the resin composition, but was poor in copper low dissolution and heat resistance.

[0115] From the evaluation results of the examples and the comparative examples, it was found that the dispersing agent composed of the prescribed polyether ester compound is excellent in copper low elution property and heat resistance, and can reduce the shear viscosity of the resin composition, and that the dispersing agent is effective as a constituent component of a resin composition containing inorganic powder. In addition, it was found that the resin composition containing the dispersing agent composed of the prescribed polyether ester compound is suitable as a semiconductor packaging material.

Claims

1. A dispersant comprising a polyether ester compound represented by the following formula (1), In formula (1), R 1 is a hydrocarbon group having 1 to 22 carbon atoms, AO is an oxyalkylene group having 2 to 4 carbon atoms, n is the average number of added moles of the oxyalkylene group, which is 1 to 60, and R 2 It is a phenolic hydroxyl group, and m is a number of 2 to 3.

2. A resin composition comprising an inorganic powder, a resin, and the dispersant according to claim 1, wherein the inorganic powder is dispersed in the resin, and the dispersant is contained in an amount of 0.1 to 50 parts by mass based on 100 parts by mass of the inorganic powder.

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