JP3195187B2 - Epoxy resin composition for dispenser application - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dispenser coating epoxy resin composition suitable for mounting components such as electronic components, and particularly for fixing surface mounting components on a printed circuit board.

[0002]

2. Description of the Related Art Conventionally, an epoxy resin composition has been used as an adhesive for bonding and fixing a surface mounting component on a printed circuit board. Such compositions include:
There is known an epoxy resin, an amine-based curing agent, and a hydrophilic silica as a thixotropic agent (rheological additive) (JP-A-4-33916). This epoxy resin composition has a small change in viscosity with time and does not spread the application surface during curing, and has excellent applicability with a dispenser. On the other hand, when applying an epoxy resin composition to an object by a dispenser, high-speed application is demanded in order to increase the application efficiency. The above-mentioned conventional epoxy resin composition has not been satisfactory from the viewpoint of high-speed coating properties. That is, when the conventional composition is applied using a dispenser, it is difficult to apply the composition at high speed because the composition has poor thread breaking properties.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides an epoxy resin composition having good thread breakability required for high-speed coating when applied using a dispenser, and further provides thread breakability and storage stability. It is an object of the present invention to provide an epoxy resin composition excellent in both of these.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, a liquid epoxy resin, an amine-based latent curing agent, a calcined talc, and an organic-based rheological additive, wherein the R value represented by the following formula (1) is 0.4 or less. An epoxy resin composition for dispenser application is provided. R = η ₁₀ / Sc (1) (wherein, η ₁₀ indicates a viscosity (Pa · s) at a shear rate of ₁₀ sec ⁻¹ , and Sc indicates a Casson yield value obtained from the Casson equation). This will be described in more detail.

[0005] The liquid epoxy resin used in the composition of the present invention has two or more epoxy groups in one molecule.
Conventionally well-known ones can be used.
Such materials include, for example, bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin,
Bisphenol AD epoxy resin, Bisphenol F
Epoxy resin, carboxylic acid glycidyl ester type epoxy resin, phenol novolak type epoxy resin, urethane-modified bisphenol A type epoxy resin, and the like. These can be used alone or in the form of a mixture. In this liquid epoxy resin, an appropriate amount of a normal-temperature solid epoxy resin can be dissolved if necessary.

As the amine-based latent curing agent, those known in the art, such as dicyandiamide and its derivatives, imidazole compounds, organic hydrazides, amine adduct compounds, spiroacetal compounds, modified polyamides,
A heat-soluble curing agent such as a modified polyamine or an amine-urea adduct compound can be used alone or in combination. Specific examples thereof include, as imidazole compounds, 2-heptadecyl imidazole (C17Z), 2-phenyl-4,
5-dihydroxymethylimidazole (2PHZ), phenyl-4-methyl-5-hydroxymethylimidazole (2P4MHZ), 2-phenyl-4-benzyl-5
-Hydroxymethylimidazole (2P4BHZ),
2,4-diamino-6- {2-methylimidazolyl-
(1)｝ -ethyl-5-triazine (2MA) and an isocyanuric acid adduct of this 2MA (2MA-OK). Organic hydrazides include succinic hydrazide, adipic hydrazide, isophthalic hydrazide,
o-oxybenzoic acid hydrazide, salicylic acid hydrazide and the like.

As the amine adduct compound, various commercially available products, for example, Amicure PN-23 (Ajinomoto Co., Inc.)
Amicure MY-24 (manufactured by Ajinomoto Co., Inc.),
NOVACURE HX-3721, HX-3741 (manufactured by Asahi Kasei Corporation) and the like. Spiroacetal-based compounds include various commercially available products, for example, Amicure AT
U Carba Mate 3 (manufactured by Ajinomoto Co., Inc.) and the like. As the modified polyamide, Hardner HT939
(Nippon Ciba-Geigy), as a modified polyamine, Hardner H4070S (manufactured by AC R), and as an amine-urea adduct-based compound, Fuji Cure FXE-1000 (manufactured by Fuji Kasei). Can be The proportion of the amine latent curing agent used is 3 to 60 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts by weight of the epoxy resin.

[0008] As the organic rheology additive, conventionally known ones can be used. As such a thing, for example, a modified castor oil-based rheological additive, an organic amide-based rheological additive, and the like are known. The modified castor oil-based rheology additive is obtained by hydrogenating castor oil, and is sold by RHEOX under the trade name “THIXCIN-R”. Organic amide-based rheological additives include polycarboxylic acids such as sebacic acid, dodecanedicarboxylic acid and dimer acid, and 1,6-diaminohexane and 1,6-diaminohexane.
It is obtained by reacting an active hydrogen compound such as 8-diaminooctane and 1,6-hexanediol with a hydroxycarboxylic acid as a capping agent such as ricinoleic acid and 12-hydroxystearic acid. This is described in detail in JP-A-145332. The amount of the organic rheological additive is 10
The amount is generally 0.1 to 15 parts by weight, preferably 1 to 10 parts by weight with respect to 0 parts by weight, but is selected in relation to a desired R value.

The calcined talc used in the present invention is obtained by calcining talc at a temperature higher than the temperature at which dehydration of crystallization water occurs, usually at 900 to 1200 ° C., and has an average particle size of 0.5 to 20 μm, preferably 1 to 10 μm. Have By using this calcined talc, a composition having a long pot life and excellent storage stability can be obtained. The amount of the calcined talc is usually 1 to 100 parts by weight of the liquid epoxy resin.
100 parts by weight, preferably 5 to 50 parts by weight,
Selected in relation to the value.

A reactive diluent may be added to the composition of the present invention, if necessary. Such a diluent has at least one epoxy group in the molecule and can be used at normal temperature and normal pressure. , Low-viscosity compounds, specifically, phenylglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether,
Examples include methyl glycidyl ether, propyl glycidyl ether, pentaethritol polyglycidyl ether, sorbitol polyglycidyl ether, n-butyl glycol glycidyl ether, 2-ethylhexyl glycidyl ether, and the like. This reactive diluent is used to adjust the viscosity of the composition.

The composition of the present invention may optionally contain, if necessary, any components conventionally incorporated in this type of composition within a range that does not impair the object of the present invention. Representative examples of such additives include pigments, defoamers, leveling agents and the like.

In the composition of the present invention, the above formula (1)
Is adjusted to 0.4 or less. According to the study of the present inventors, it has been found that by maintaining the R value at 0.4 or less, a composition having good thread breakability and capable of being applied at a high speed using a dispenser can be obtained. The R value can be controlled mainly by the type and particle size of the inorganic filler, the amount of the organic rheological additive, and the like. Therefore, when preparing the composition of the present invention, the specific type and the amount of the additive component may be appropriately determined according to the desired R value.

[0013]

When the composition of the present invention is applied using a dispenser, the composition is free from yarn twisting, has excellent thread breaking properties, and can be easily applied at high speed. Also,
In the composition of the present invention, those containing calcined talc as an inorganic filler have excellent yarn breaking properties, a long pot life, and excellent storage stability. The composition of the present invention is suitable as an adhesive, and is particularly suitable for attaching a surface mounting component such as an electronic component. There is no particular difficulty in carrying out the method for producing the composition of the present invention, and it can be easily carried out using a conventional stirrer as in the conventional method.

[0014]

EXAMPLES The present invention will now be described in detail with reference to Examples, in which all "parts" shown below are parts by weight.

Example 1 Various compositions having the component compositions shown in Table 1 were prepared, and the relationship between the R value and high-speed coating property was examined. The results are shown in Table 1. The R value and high-speed coating property were measured as follows. (Measurement of R _{values) R = η 10 / Sc (} 1) η 10: the viscosity at a shear rate 10sec ^-1 Sc: Casson Casson emitter breakdown <br/> value obtained from the equation First, a rotational viscometer [Corporation Tokimec EHD rotary viscometer (cone diameter: 28 mm, cone angle 3 degrees)]
At 25 ° C., the rotation speed of the cone plate was 0.5, 1.0, 2.5, 5.0, 10.0 (rpm).
In order. At each rotation speed, the viscosity η (Pa · s) and shear stress S (Pa) 5 minutes after the start of rotation are determined. In the case of this viscometer, the number of rotations is 0.5, 1.0,
Shear speeds D (sec ^-1 ) at 2.5, 5.0 and 10.0 (rpm) are 1.0, 2.0, 5.0 and 5.0, respectively.
10.0 and 20.0 (sec ^-1 ). Next, from the shear rate D and the shear stress S obtained as described above,
sson was asked to Casson emitter breakdown value Sc by the formula. ^{S 1/2 = (Sc) 1/2 +} (μc × D) 1/2 (2) ( wherein, Sc is Casson emitter breakdown values, [mu] c is Casso
n Viscosity D denotes the shear rate) Casson emitter breakdown value is obtained specifically as follows. After measuring the relationship between the shear rate D and the shear stress S, the viscosity S /
D was calculated. As the viscosity η ₁₀ in the R value calculation formula (1), the viscosity (Pa) at the shear rate D = ₁₀ sec ⁻¹
・ S) was used. First, the respective values of D and S obtained as described above are plotted on a graph paper with S ^1/2 as the horizontal axis and D ^1/2 as the vertical axis to form a straight line. By extrapolating this straight line, the value (Sc) ^1/2 at the point where the straight line crosses the horizontal axis was obtained, and then this value was squared to calculate Sc.

(Evaluation of high-speed coating property)
Coating liquid temperature: 28 ° C, dispenser nozzle inner diameter: 0.
The coating was performed at 7 mm with a tact time of coating of 0.12 seconds.
In this case, the coating pressure of the dispenser was adjusted so that the diameter of the coating material formed on the substrate was 1.4 mm. The time (shot time) for discharging the composition from the dispenser was fixed at 0.05 seconds. In this way, 5000 points were continuously applied on the substrate. FIG. 1 shows the state of the applied material in this case. In FIG. 1, reference numeral 1 denotes a substrate as a coating substrate, 2 denotes a coating material, and 3 denotes a stringing portion. R (1) indicates the stringing length, and R (2) indicates the application diameter of the applied material. In the state of the coated material shown in FIG. 1, the one in which the stringing length R (1) exceeds 20% of the coated diameter R (2) was determined to be defective. Then, the yarn breaking property of the composition was determined according to the following evaluation criteria. 〇: 0 to 50 defectives out of 5,000 points. Δ: The number of defects is more than 50 to less than 100 out of 5,000 points ×: The number of defects is more than 100 out of 5,000 points

(Pot life) The initial viscosities of each composition after preparation and the viscosities of each composition after storage at 40 ° C. for 3 weeks were measured, and the rate of change in viscosity was calculated by the following equation. In this case, the viscosity was measured at 25 ° C. using the same viscometer as used in the measurement of the R value, and the rotational speed of the cone plate was set at 0.
It was calculated based on the measured value under the condition of 5 rpm. Viscosity change rate (%) = A / B × 100 A: Viscosity of composition after storage at 40 ° C. for 3 weeks B: Initial viscosity of composition The pot life of the composition was evaluated according to the following criteria. ×: The rate of change in viscosity exceeded 130% Δ: The rate of change in viscosity was more than 110% to 130% 〇: The rate of change in viscosity was more than 90% to 110% △: Change in viscosity The rate is more than 70% to 90%. ×: The rate of change in viscosity is less than 70%.

The contents of the components shown in Table 1 are as follows. (A) Liquid epoxy resin Bisphenol A type epoxy resin, “Epicoat 82
8 ", manufactured by Yuka Ciel Epoxy Co., Ltd. (B) Latent curing agent (B-1) Amine adduct," Amicure PN-2
3 ", manufactured by Ajinomoto Co., Inc. (B-2) Modified polyamide type," Hardner HT93
9 ", manufactured by Ciba Geigy (B-3) Modified aliphatic polyamine type," ACR Hardener H-4070S ", manufactured by ACR Co., Ltd. (C) Rheology additive Castor oil-based rheology additive, (trade name" THIXCI
(N-R), white fine powder, melting point: 86 ° C., manufactured by RHEOX) (D) Inorganic filler (D-1) hydrophilic silica (“AEROSIL # 30”)
0 ", manufactured by Nippon Aerosil Co., Ltd.) (D-2) Hydrophobic silica (silicon oil treated product," A
(EROSIL R202, manufactured by Nippon Aerosil Co., Ltd.) (D-3) Fired talc (talc fired at a temperature of 1100 ° C. and made enstatite, trade name “Enstack 24”, average particle size 3.0 μm, Asada Flour Milling Co., Ltd.) (D-4) “Talc” (trade name “LMP-100”, average particle size 3.0 μm), manufactured by Fuji Talc Kogyo Co., Ltd. (D-5) silica (trade name “Imsil A108”, manufactured by Tatsumori Corporation)

[0019]

[Table 1]

[Brief description of the drawings]

FIG. 1 shows a state diagram of a coating material when a composition is applied on a coating substrate using a dispenser. (A): Side view (b): Plan view

[Description of Signs] 1 Coating substrate 2 Coating material 3 Stringing part R (1) Stringing length R (2) Coating diameter of coating material

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI H05K 1/18 H05K 1/18 F (56) References JP-A-4-33916 (JP, A) JP-A-61-209276 ( JP, A) JP-A-6-57101 (JP, A) JP-A-6-25633 (JP, A) JP-A-4-331270 (JP, A) JP-A-6-107906 (JP, A) JP-A-63-156817 (JP, A) JP-A-63-301214 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB names) C08L 63/00-63/10 C08K 3/34 C08G 59 / 50 C09D 163/00-163/10 C09J 163/00-163/10 H05K 1/18

Claims (1)

(57) [Claims] 1. A liquid epoxy resin, an amine-based latent curing agent, calcined talc, and an organic-based rheological additive, wherein the R value represented by the following formula (1) is 0.4 or less. An epoxy resin composition for dispenser application. R = η ₁₀ / Sc (1) (where, η ₁₀ indicates a viscosity (Pa · s) at a shear rate of ₁₀ sec ⁻¹ , and Sc indicates a Casson yield value obtained from the Casson equation)