Resin composition, conductive adhesive, cured product, and semiconductor device

Abstract

Provided are: a resin composition which has a low modulus, can cure at low temperatures, and has a long pot-life and which is useful as electroconductive adhesives, materials for mounting components, sealants for protecting components, and insulating materials for reinforcement, for use in the field of flexible hybrid electronics (FHE); an electroconductive adhesive comprising the resin composition; a cured object formed from the resin composition; and a semiconductor device including a cued object formed from the electroconductive adhesive or resin composition. The resin composition comprises (A) a radical-polymerizable curable resin, (B) a free-radical polymerization initiator, and (C) a radical polymerization inhibitor, wherein the (C) component comprises (C1) a nitrosoamine compound and the (A) component comprises (A1) a urethane acrylate oligomer, the (A1) component having a mass-average molecular weight of 1,600-20,000.

Description

[Technical Field]

[0001] The present invention relates to a resin composition used in fields such as flexible hybrid electronics (hereinafter referred to as FHE), a conductive adhesive containing this composition, a component mounting material or a sealing material for protecting components, and a reinforcing insulating material, as well as cured products of these adhesives, sealing materials, or insulating materials, and further to semiconductor devices containing these cured products. [Background technology]

[0002] In recent years, wearable applications using the Internet have been attracting increasing attention. Applications in the field of FHE, such as biosensors, are being developed, mainly in the sports and healthcare fields.

[0003] For wearable applications, biosensors are being developed that are attached to the human body in the form of wristbands, clothing, glasses, etc. Therefore, materials suitable for wearable applications that can accommodate the bending and stretching of the human body surface are required.

[0004] In these applications, when adding electrical functionality to anything, it is necessary to form wiring and mount sensors, capacitors, processors, memory, etc. In the FHE field, semiconductors such as processors and memory mounted on these flexible wiring boards cannot be made stretchable. Therefore, low-elasticity conductive adhesives are required to mount these semiconductors on flexible wiring boards.

[0005] As an example of a conductive adhesive, Patent Document 1 listed below discloses "a conductive resin composition characterized by containing (A) an epoxy resin, (B) a compound having a (meth)acryloyl group and a glycidyl group, (C) a phenolic resin-based curing agent, (D) a radical polymerization initiator, and (E) conductive particles."

[0006] In addition, the following Patent Document 2 discloses a compound of the formula (A): -R1 -O-[wherein, R 1 is a hydrocarbon group having 1 to 10 carbon atoms.] and terminal groups which are hydrolyzable silyl groups, and (B) a conductive adhesive containing silver particles. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2013 / 035685 [Patent Document 2] Japanese Patent Application Publication No. 2018-048286 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the cured products of these conventional connecting materials have a high elastic modulus. For example, when applied to applications that require the material to follow human movement, such as wearable applications, the cured products cannot follow the movement of the human body. This can cause parts to fall off. Furthermore, the material can even impede human movement.

[0009] Furthermore, the plastics and thermoplastic polyurethanes (TPUs) typically used as substrates in wearable applications are heat-sensitive. Therefore, when adding electrical functionality to wearable applications, conventional connection methods using solder or thermosetting epoxy resin-based conductive adhesives cannot withstand the solder melting point or the curing temperature of the conductive adhesive. This can result in damage to the substrate itself. Therefore, low elasticity and low-temperature curing are important for conductive adhesives, component mounting materials or encapsulants for component protection, and reinforcing insulating materials for FHE applications. Furthermore, a long pot life is also required for ease of use.

[0010] In view of the above, an object of the present disclosure is to provide a resin composition that has low elasticity, can be cured at low temperatures, and has a long pot life, a conductive adhesive containing the resin composition, a cured product of the resin composition, and a semiconductor device that contains the conductive adhesive or the cured product of the resin composition. This resin composition is useful as a conductive adhesive, a component mounting material or a sealant for protecting components, and a reinforcing insulating material for the FHE field. [Means for solving the problem]

[0011] A resin composition according to one embodiment of the present disclosure includes (A) a radically polymerizable curable resin, (B) a radical polymerization initiator, and (C) a radical polymerization inhibitor. The (C) component includes (C1) a nitrosamine compound. The (A) component includes (A1) a urethane acrylate oligomer. The (A1) component is a urethane acrylate oligomer having a mass average molecular weight of 1,600 or more and 20,000 or less. The details of this embodiment will be explained in the following description of this specification.

[0012] According to the present invention, there is provided a resin composition that can be cured at low temperatures and has low elasticity and a long pot life, and is useful as a conductive adhesive for mounting components in the FHE field. Furthermore, according to the present invention, a resin composition suitable for use in conductive adhesives for the FHE field, component mounting materials or component protection sealants, and reinforcing insulating materials, as well as a cured product of the resin composition, can be obtained, thereby enabling the production of highly reliable semiconductor devices. The resin composition of the above embodiment may contain, in particular, a (C1) nitrosamine compound as the (C) radical polymerization inhibitor, and an (A1) urethane acrylate oligomer having a mass-average molecular weight of 1,600 to 20,000 as the (A) radically polymerizable curable resin. This results in a resin composition that can be cured at low temperatures and has a long pot life. This resin composition is suitable for use in conductive adhesives for the FHE field, component mounting materials or encapsulants for component protection, and reinforcing insulating materials.

[0013] In the resin composition of the above embodiment, component (B) contains an organic peroxide having a 10-hour half-life temperature of 165°C or less, and the content thereof is preferably 0.1 to 30 parts by mass per 100 parts by mass of component (A). By containing an organic peroxide having a 10-hour half-life temperature of 165°C or less, the resin composition can be cured at a relatively low temperature.

[0014] In the resin composition of the above embodiment, the component (A) preferably further contains an (A3) bismaleimide resin. By including the (A3) bismaleimide resin, suitable stability such as heat resistance and moisture resistance, flexibility, etc. can be obtained.

[0015] In the resin composition of the above embodiment, the component (A) preferably further contains an acrylate monomer (A2). More preferably, the resin composition contains an acrylate monomer (A2) having a glass transition temperature (Tg) of 15°C or higher. Particularly preferably, the mass ratio of the urethane acrylate oligomer (A1) to the acrylate monomer (A2) is 5:95 to 60:40. The inclusion of the acrylate monomer (A2) improves workability and also provides an appropriate storage modulus.

[0016] In the resin composition of the above embodiment, the urethane acrylate oligomer (A1) is preferably contained in an amount of 5 to 50 parts by mass per 100 parts by mass of the component (A). When the urethane acrylate oligomer (A1) is contained in this range, excellent flexibility can be imparted without impairing workability and reactivity.

[0017] In the resin composition of the above embodiment, the content of the component (C) is preferably 0.1 to 5 parts by mass per 100 parts by mass of the component (B), which makes it possible to suppress unintended radical polymerization reactions.

[0018] The resin composition of the above form preferably has a room temperature modulus of 0.01 GPa to 1.6 GPa after being left for 60 minutes at 70° C. This allows the cured product of the resin composition to have excellent flexibility and extensibility.

[0019] The resin composition of the above form preferably contains insulating particles or conductive particles. This allows the resin composition to be used for FHE applications, particularly as a cured product of a conductive adhesive, a sealant, an insulating material, etc. The conductive adhesive and the cured product are suitable for use in semiconductor devices. DETAILED DESCRIPTION OF THE INVENTION

[0020] A resin composition according to one embodiment of the present disclosure will be described below, although the present embodiment is not limited to the embodiment described below.

[0021] <Resin composition> A resin composition according to one embodiment of the present disclosure (hereinafter referred to as the present resin composition) includes (A) a radically polymerizable curable resin, (B) a radical polymerization initiator, and (C) a radical polymerization inhibitor. The component (C) includes (C1) a nitrosamine compound. The component (A) includes (A1) a urethane acrylate oligomer. The component (A1) is a urethane acrylate oligomer having a mass average molecular weight of 1,600 or more and 20,000 or less.

[0022] <(A) Radical Polymerizable Curable Resin> (A) The radically polymerizable curable resin refers to a resin that cures as radical polymerization proceeds. The curable resin imparts curability and other properties to the resin composition. The radically polymerizable curable resin has a fast polymerization rate. Therefore, curing can be carried out quickly. Such a curable resin is not particularly limited as long as it has radical polymerization properties. Preferably, the radically polymerizable curable resin is liquid. Use of a liquid curable resin eliminates the need for a solvent. Therefore, the generation of voids in the resin composition can be suppressed. When a solvent is used, the amount of the solvent is preferably less than 3 parts by mass, more preferably less than 1 part by mass, and most preferably no solvent, per 100 parts by mass of the resin composition.

[0023] Examples of the radically polymerizable curable resin (A) include (A1) urethane acrylate oligomer, (A2) acrylate monomer, and (A3) bismaleimide resin. The resin composition contains at least (A1) a urethane acrylate oligomer. The resin composition may further contain either or both of (A2) an acrylate monomer and (A3) a bismaleimide resin. The (A) radically polymerizable curable resin is contained in an amount of preferably 5 to 90 parts by mass, more preferably 8 to 30 parts by mass, and particularly preferably 8 to 20 parts by mass per 100 parts by mass of the resin composition.

[0024] <(A1) Urethane acrylate oligomer> The (A1) urethane acrylate oligomer may have a mass-average molecular weight of 1,600 to 20,000. By using an (A1) urethane acrylate oligomer having a mass-average molecular weight within this range, the workability and reactivity of the resin composition are not impaired, and the cured resin composition exhibits low elasticity and good extensibility. From this perspective, the mass-average molecular weight is preferably 1,600 to 20,000, more preferably 2,000 to 18,000, and particularly preferably 3,000 to 15,000. One (A1) urethane acrylate oligomer may be used alone. Alternatively, two or more (A1) urethane acrylate oligomers may be used in combination. Furthermore, (A1) urethane acrylate oligomers having different mass-average molecular weights may be used in combination. However, if (A1) urethane acrylate oligomers having a mass average molecular weight exceeding 20,000 are contained, workability may be impaired due to high viscosity. At the same time, reactivity may be impaired due to steric hindrance. Therefore, it is preferable that (A1) urethane acrylate oligomers having a mass average molecular weight exceeding 20,000 are substantially not contained. It is also preferable that (A1) urethane acrylate oligomers having a mass average molecular weight of less than 1,600 are substantially not contained. In the present disclosure, the term "substantially free" means that the substance is not intentionally included in the composition, specifically, that the content in the composition is less than 0.1% by mass. The mass average molecular weight in the present disclosure can be measured by gel permeation chromatography. The number of functional groups of the (A1) urethane acrylate oligomer is preferably 1 to 5, more preferably 1 to 4, and even more preferably 1 to 3. When the number of functional groups is within this range, the crosslink density of the cured product of the resin composition is reduced. Furthermore, good flexibility and extensibility can be imparted to the resin composition.

[0025] Specific examples of commercially available urethane acrylate oligomers (A1) used include urethane acrylate oligomers "MBA-2CZ" (mass average molecular weight 1,600), "UN-333" (3,000), "UN-6200" (mass average molecular weight 6,500), and "UN-6304" (mass average molecular weight 13,000) manufactured by Negami Chemical Industrial Co., Ltd., and urethane acrylate oligomers "UV-3200B" (mass average molecular weight 10,000) and "UV-3000B" (mass average molecular weight 18,000) manufactured by Mitsubishi Chemical Corporation.

[0026] The (A1) urethane acrylate oligomer is preferably contained in an amount of 5 to 50 parts by mass per 100 parts by mass of the (A) radically polymerizable curable resin. If this content is less than 5 parts by mass, the room temperature elastic modulus of the resin composition becomes high. As a result, the flexibility of the resin composition may be lost. On the other hand, if the content exceeds 50 parts by mass, the low-temperature curing property and workability of the resin composition become poor. From this viewpoint, the (A1) urethane acrylate oligomer is more preferably contained in an amount of 6 to 30 parts by mass, and particularly preferably 7 to 20 parts by mass, per 100 parts by mass of the (A) radically polymerizable curable resin.

[0027] <(A2) Acrylate Monomer> The present resin composition may contain (A2) an acrylate monomer. The acrylate monomer (A2) is not particularly limited. Preferred examples include monofunctional acrylate monomers such as phenoxyethyl acrylate and isobornyl acrylate. In the case of a polyfunctional acrylate monomer having two or more (meth)acryloyl groups in one molecule, a linear alkylene skeleton having 4 to 30 carbon atoms or a linear oxyalkylene skeleton having 4 to 30 carbon atoms is preferably contained between adjacent (meth)acryloyl groups. By including the acrylate monomer (A2) in the resin composition, the room temperature modulus and workability are improved. From the viewpoint of imparting flexibility to the cured product, the (A2) acrylate monomer preferably contains an acrylate monomer having a glass transition temperature (Tg) of 15°C or lower. On the other hand, if only an acrylate monomer having a glass transition temperature (Tg) of 15°C or lower is contained, oxygen inhibition of the cured product surface is significant. As a result, unwanted tack (stickiness) may occur. In this case, it is preferable to also contain an acrylate monomer having a glass transition temperature (Tg) of 15°C or higher. Inclusion of an acrylate monomer having a glass transition temperature (Tg) of 15°C or higher can reduce the occurrence of tack due to oxygen inhibition of the cured product surface. Note that, from the viewpoint of imparting flexibility, the amount of acrylate monomer having a glass transition temperature (Tg) of 15°C or lower is contained in greater amounts than the amount of acrylate monomer having a glass transition temperature (Tg) of 15°C or higher. The glass transition temperature (Tg) of the acrylate monomer can be measured as the glass transition temperature (Tg) of the homopolymer using dynamic mechanical analysis (DMA) or a thermomechanical analyzer (TMA). One (A2) acrylate monomer may be used alone, or two or more (A2) acrylate monomers may be mixed and used.

[0028] Specific examples of the (A2) acrylate monomer used include "Light Acrylate PO-A" (Tg: -22°C), a phenoxyethyl acrylate manufactured by Kyoeisha Chemical Co., Ltd., and "Light Acrylate IB-XA" (Tg: 94°C), an isobornyl acrylate.

[0029] The (A2) acrylate monomer is preferably contained in an amount of 3 to 75 parts by mass per 100 parts by mass of the (A) radically polymerizable curable resin. If the content is less than 3 parts by mass, the viscosity becomes high. This reduces handleability and workability. If the content exceeds 75 parts by mass, the crosslink density becomes high. This tends to increase the elastic modulus, i.e., tends to decrease flexibility. From this viewpoint, the amount of the (A2) acrylate monomer is more preferably 25 to 70 parts by mass, and particularly preferably 30 to 65 parts by mass, per 100 parts by mass of the (A) radically polymerizable curable resin.

[0030] The mass ratio (A1:A2) of the (A2) acrylate monomer to the (A1) urethane acrylate oligomer is preferably 5:95 to 60:40. When the mass ratio is within this range, the resin composition maintains an appropriate viscosity. In other words, the resin composition is easier to handle, maintaining good workability. Moreover, an excellent cured product having low elasticity and extensibility is obtained. From these viewpoints, the mass ratio (A1:A2) is more preferably 7:93 to 50:50, and particularly preferably 10:90 to 30:70.

[0031] <(A3) Bismaleimide resin> The resin composition may contain (A3) a bismaleimide resin. The bismaleimides used in this embodiment may include solid bismaleimides. However, liquid bismaleimides are more preferably used. Solid bismaleimides have low solubility in common organic solvents. Therefore, when solid bismaleimides are used, they must be diluted with a large amount of organic solvent. However, in this case, the solvent that volatilizes during curing may form voids. These voids lead to reduced adhesive strength and cracking. To avoid this, a method can be used in which solid bismaleimides are dispersed in the resin composition using a roll mill or the like. However, this method increases the viscosity of the resin composition. On the other hand, resin compositions containing liquid bismaleimides have low viscosity. This improves workability when using the resin composition.

[0032] The (A3) bismaleimide resin is not particularly limited. Any compound having a chemical structure sandwiched between two maleimide groups can be used. By including the (A3) bismaleimide resin in the present resin composition, a cured product having excellent stability (heat resistance, moisture resistance) while maintaining flexibility can be obtained. From this perspective, the mass-average molecular weight of the (A3) bismaleimide resin is preferably 500 to 7000, more preferably 750 to 5500, and particularly preferably 1000 to 3000. Furthermore, a dimer acid-modified bismaleimide can also be used as the (A3) bismaleimide resin. Examples of dimer acid-modified bismaleimides include liquid bismaleimides BMI-1500 and BMI-1700, and solid bismaleimide BMI-3000 (all manufactured by Designer Molecules). By using a dimer acid-modified bismaleimide, the room temperature elastic modulus of the resin composition can be kept low. This is thought to be because the dimer acid-modified bismaleimide has reactive maleimide groups only at both ends, and therefore no crosslinkable reactive groups are present in the molecular chain. One (A3) bismaleimide resin may be used alone, or two or more (A3) bismaleimide resins may be used in combination.

[0033] The (A3) bismaleimide resin is preferably contained in an amount of 5 to 40 parts by mass relative to 100 parts by mass of the (A) radical-polymerizable curable resin. If the content is less than 5 parts by mass, reliability and strength decrease. If the content exceeds 40 parts by mass, flexibility is lost. From these viewpoints, the (A3) bismaleimide resin is more preferably contained in an amount of 10 to 35 parts by mass, and particularly preferably 15 to 30 parts by mass, relative to 100 parts by mass of the (A) radical-polymerizable curable resin.

[0034] The mass ratio (A1:A3) of the (A3) bismaleimide resin to the (A1) urethane acrylate oligomer is preferably 10:90 to 80:20. When the mass ratio is in this range, reliability and strength can be maintained, and flexibility can also be maintained. From this viewpoint, the mass ratio (A1:A3) is more preferably 15:85 to 70:30, and particularly preferably 20:80 to 60:40.

[0035] <(B) Radical Polymerization Initiator> The radical polymerization initiator (B) initiates radical polymerization of the radically polymerizable curable resin (A) to cure the resin. A preferred radical polymerization initiator (B) is an organic peroxide from the viewpoint of reactivity with the radically polymerizable curable resin (A).

[0036] Examples of organic peroxides that can be used include peroxydicarbonate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butylcumyl peroxide, dicumyl peroxide, dilauroyl peroxide, dibenzoyl peroxide, 1,1-di(t-hexylperoxy)cyclohexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylperoxy-2-ethylhexyl monocarbonate, α,α'-di(t-butylperoxy)diisopropylbenzene, n-butyl 4,4-di(t-butylperoxy)valerate, t-hexylperoxyisopropyl monocarbonate, t-butylperoxylaurate, and 2-di(t-butylperoxy)butane. One (B) radical polymerization initiator may be used alone. Alternatively, two or more (B) radical polymerization initiators may be used in combination.

[0037] The organic peroxide used as the radical polymerization initiator (B) preferably has a 10-hour half-life temperature of 165°C or lower. This allows the resin composition to be cured at a relatively low temperature. From this perspective, the 10-hour half-life temperature is more preferably 120°C or lower, and particularly preferably 100°C or lower. Although not particularly limited, the lower limit is preferably 28°C or higher, more preferably 30°C or higher, and particularly preferably 35°C or higher. The 10-hour half-life temperature is the temperature at which the organic peroxide decomposes and loses half of its amount in 10 hours. If the 10-hour half-life temperature is below 28°C, the reactivity may become too high, resulting in a decrease in reaction stability.

[0038] Specific examples of the radical polymerization initiator (B) used include "Peroyl TCP" (10-hour half-life temperature: 40.8°C), a peroxydicarbonate manufactured by NOF Corporation; "Perocta O" (10-hour half-life temperature: 65.3°C), a 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate; "Perbutyl C" (10-hour half-life temperature: 119.5°C), a t-butylcumyl peroxide; "Percumyl D" (10-hour half-life temperature: 116.4°C), which is a mil peroxide; "Perloyl L" (10-hour half-life temperature: 61.6°C), which is a dilauroyl peroxide; "Nyper FF" (10-hour half-life temperature: 73.6°C), which is a dibenzoyl peroxide; "Perhexa HC" (10-hour half-life temperature: 87.1°C), which is 1,1-di(t-hexylperoxy)cyclohexane; and 2,5-dimethyl-2, 5-di(t-butylperoxy)hexane "Perhexa 25B" (10-hour half-life temperature: 117.9°C), t-butylperoxy-2-ethylhexyl monocarbonate "Perbutyl E" (10-hour half-life temperature: 99.0°C), α,α'-di(t-butylperoxy)diisopropylbenzene "Perbutyl P" (10-hour half-life temperature: 119.2°C), n-butyl 4,4-di(t-butylperoxy)valerate Examples include "Perhexa V" (10-hour half-life temperature: 104.5°C), t-hexylperoxyisopropyl monocarbonate "Perhexyl I" (10-hour half-life temperature: 95.0°C), t-butylperoxylaurate "Perbutyl L" (10-hour half-life temperature: 98.3°C), and 2,2-di(t-butylperoxy)butane "Perhexa 22" (10-hour half-life temperature: 103.1°C).

[0039] The amount of (B) radical polymerization initiator is preferably 0.1 to 30 parts by mass, more preferably 3 to 20 parts by mass, and particularly preferably 6 to 15 parts by mass, per 100 parts by mass of (A) radically polymerizable curable resin. If the amount of (B) radical polymerization initiator is too large, unreacted (B) radical polymerization initiator may remain in the cured product of the resin composition after curing. In this case, residual heat may occur.

[0040] <(C) Radical Polymerization Inhibitor> The radical polymerization inhibitor (C) inhibits the radical polymerization of the radically polymerizable curable resin (A) and thereby extends the pot life of the resin composition, which refers to the time during which the resin composition remains usable. Examples of the radical polymerization inhibitor (C) that can be used include nitrosamine compounds such as aluminum salts of nitrosamine, hydroquinone, and 2,2,6,6-tetramethyl-1-oxyl. Among these, nitrosamine compounds such as aluminum salts of nitrosophenylhydroxyamine are preferred. This allows the reaction to be prevented without inhibiting it, and prevents unintended radical polymerization reactions at room temperature (normal temperature). One radical polymerization inhibitor (C) may be used alone, or two or more radical polymerization inhibitors (C) may be used in combination, although preferably only a nitrosamine compound is used.

[0041] Specific examples of commercially available (C) radical polymerization inhibitors include "Q1301," an aluminum salt of nitrosamine, and "HQ," a hydroquinone, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., as well as "TEMPO," a 2,2,6,6-tetramethyl-1-oxyl, manufactured by Koei Chemical Industry Co., Ltd.

[0042] The radical polymerization inhibitor (C) is preferably contained in an amount of 0.1 to 5 parts by mass, more preferably 0.5 to 1.7 parts by mass, and particularly preferably 0.9 to 1.3 parts by mass, per 100 parts by mass of the radical polymerization initiator (B). By containing the radical polymerization inhibitor within this range, the radical polymerization of the radically polymerizable curable resin (A) is appropriately suppressed, while the reaction during curing is not inhibited. In this way, unintended radical polymerization reactions at room temperature (normal temperature) can be suppressed.

[0043] <Other ingredients> The resin composition may contain other components. For example, it may contain (D1) conductive particles or (D2) insulating particles. One (D1) conductive particle or one (D2) insulating particle may be used alone. Alternatively, two or more types of (D1) conductive particles or two or more types of (D2) insulating particles may be mixed and used.

[0044] <(D1) Conductive particles> In the present invention, the (D1) conductive particles refer to particles having an average particle size of 0.01 μm to 100 μm and an electrical conductivity of 10 S / m or more. A conductive material formed into a particle shape can be used. Alternatively, a core (core particle) coated with a conductive material may be used. The core (core particle) may be made of a non-conductive material as long as even a portion of it is coated with a conductive material. Examples of the (D1) conductive particles include metal powder and coated powder. The conductive particles (D1) are used to impart thermal conductivity and / or electrical conductivity to the resin composition. There are no particular limitations on the conductive material. Examples of such conductive materials include gold, silver, nickel, copper, palladium, platinum, bismuth, tin, alloys thereof (especially bismuth-tin alloys, solder, etc.), aluminum, indium tin oxide, silver-coated copper, silver-coated aluminum, metal-coated glass spheres, silver-coated fibers, silver-coated resins, antimony-doped tin, tin oxide, carbon fibers, graphite, carbon black, and mixtures thereof. In consideration of thermal conductivity and electrical conductivity, the conductive material preferably contains at least one metal selected from the group consisting of silver, nickel, copper, tin, aluminum, silver alloys, nickel alloys, copper alloys, tin alloys, and aluminum alloys. More preferably, it contains at least one metal selected from the group consisting of silver, copper, and nickel. Even more preferably, it contains silver or copper, and most preferably, it contains silver. In one embodiment, the (D1) conductive particles are silver particles. In another embodiment, the (D1) conductive particles are copper particles. As defined above, the silver particles and copper particles comprise coated powders, which are core particles coated with silver or copper, respectively. Specific examples of the (D1) conductive particles that can be used include silver powders "EA79613" and "K79121P" manufactured by Metalor Technologies.

[0045] The content of the (D1) conductive particles is typically 95 parts by mass or less, and preferably 92 parts by mass or less, relative to 100 parts by mass of the resin composition. In one embodiment, the content of the (D1) conductive particles is 10 to 95 parts by mass, and typically 20 to 95 parts by mass, relative to 100 parts by mass of the resin composition. In another embodiment, the content of the (D1) conductive particles is 50 to 95 parts by mass, and typically 80 to 95 parts by mass, relative to the total parts by mass of the resin composition.

[0046] The shape of the (D1) conductive particles is not particularly limited. Conductive particles having any shape, such as spherical, irregular, flake-like (scale-like), filament-like (needle-like), or dendritic, can be used. Here, flake-like refers to a shape having a "major axis / minor axis" ratio (aspect ratio) of 2 or greater. It also includes flat shapes such as plate-like or scale-like. The major and minor axes of the particles constituting the conductive particles can be determined based on images obtained with a scanning electron microscope (SEM) (n=20). The "major axis" refers to the longest diameter of a line segment passing through the approximate center of gravity of a particle in a particle image obtained with the SEM. The "minor axis" refers to the shortest diameter of a line segment passing through the approximate center of gravity of a particle in a particle image obtained with the SEM. Particles having different shapes may be used in combination.

[0047] Furthermore, when the (D1) conductive particles are silver particles, the tap density thereof is preferably 1.5 g / cm 3 More preferably, 2.0 g / cm 3~6.0g / cm 3 Here, the tap density can be measured in accordance with JIS Z 2512 Metal Powder - Tap Density Measurement Method. If the tap density of the silver particles is too low, it tends to be difficult to disperse the silver particles at a high density in the cured product of the resin composition. As a result, the conductivity of the cured product tends to decrease. On the other hand, if the tap density of the silver particles is too high, separation and sedimentation of the silver particles in the resin composition tends to occur.

[0048] (D1) When the conductive particles are silver particles, their average particle size (D 50 ) is preferably 0.05 μm to 50 μm, more preferably 0.1 μm to 20 μm, and particularly preferably 0.1 μm to 15 μm, from the viewpoint of electrical conductivity and fluidity of the resin composition. Here, the average particle size refers to the particle size (median diameter) showing a cumulative frequency of 50% in the volume-based particle size distribution measured by laser diffraction.

[0049] (D1) When the conductive particles are silver particles, the specific surface area of ​​the silver particles is preferably 4.0 m 2 / g or less, more preferably 0.1m 2 / g~3.0m 2 / g. Here, the specific surface area can be measured by the BET method. If the specific surface area of ​​the silver particles is too large, the viscosity increases when the silver particles are made into a paste. This makes the silver particles less easy to handle. On the other hand, if the specific surface area of ​​the silver particles is too small, the contact area between the silver particles decreases, resulting in a decrease in conductivity.

[0050] <(D2) Insulating particles> As the (D2) insulating particles, insulating particles such as silica particles can be used, and specific examples of the (D2) insulating particles that can be used include high-purity synthetic spherical silica "SE5200SEE" (average particle size: 2 μm) manufactured by Admatechs Co., Ltd. and hydrophobic fumed silica "TS720" manufactured by Cabot Corporation.

[0051] The (D2) insulating particles are contained in an amount of preferably 0.1 to 80 parts by mass, more preferably 1 to 75 parts by mass, and particularly preferably 10 to 70 parts by mass per 100 parts by mass of the resin composition.

[0052] (D2) When the insulating particles are silica particles, their average particle size (D 50 ) is preferably 0.01 μm to 20 μm, more preferably 0.05 μm to 15 μm, and particularly preferably 0.1 μm to 10 μm. Here, the average particle size refers to the particle size (median diameter) showing a cumulative frequency of 50% in the volume-based particle size distribution measured by laser diffraction.

[0053] <Physical properties> ≪Viscosity≫ The viscosity of the resin composition can be measured at 25°C using a Brookfield RVT viscometer (spindle: SC4-14 spindle). The measured viscosity is preferably 5 Pa·s to 100 Pa·s, more preferably 10 Pa·s to 100 Pa·s, and particularly preferably 15 Pa·s to 90 Pa·s. The viscosity of the resin composition can be adjusted, for example, by adjusting the viscosity of the monomer component, adjusting the viscosity of the oligomer component, adding a solvent, adding a reactive diluent, or by adjusting the amount of inorganic particles.

[0054] <Die shear strength> The die shear strength of the resin composition is preferably 2 N / mm 2 More preferably, 3N / mm 2 More than 4N / mm 2 The die shear strength of the present resin composition can be adjusted, for example, by the molecular structure, molecular weight, or blending amount of the monomer component and oligomer component.

[0055] <Room temperature elastic modulus> The "room temperature modulus" is an index of flexibility at room temperature exhibited by a cured product of a certain resin composition. The lower the room temperature modulus, the higher the flexibility. The room temperature modulus of the present resin composition after standing at 70°C for 60 minutes is preferably 0.01 GPa to 1.6 GPa, more preferably 0.1 GPa to 1.5 GPa, and particularly preferably 0.2 GPa to 1.0 GPa. The room temperature modulus of the present resin composition can be adjusted, for example, by the molecular structure, molecular weight, or amount of the monomer and oligomer components.

[0056] Pot life "Pot life" refers to the period of time during which the adhesive composition remains usable after preparation. The pot life of the present resin composition is preferably 6 hours [h] or more, more preferably 8 hours [h] or more, and particularly preferably 12 hours [h] or more. The pot life of the present resin composition can be adjusted, for example, by the blending amounts of (B) the radical polymerization initiator and (C) the radical polymerization inhibitor.

[0057] <Manufacturing method> The resin composition can be produced by blending and stirring (A) a radically polymerizable curable resin, (B) a radical polymerization initiator, and (C) a radical polymerization inhibitor, as needed, insulating particles or conductive particles, and additionally, an interface treatment agent such as a coupling agent, a pigment, and / or a plasticizer.

[0058] A known device can be used to stir and mix these materials. For example, they can be mixed using a known device such as a Henschel mixer, a roll mill, or a three-roll mill. These raw materials can be mixed simultaneously. Alternatively, some of the materials may be mixed first, and the rest may be mixed later. The method for producing the resin composition is not particularly limited as long as the materials are sufficiently mixed.

[0059] (Supply method) The resin composition can be applied using, for example, a jet dispenser or an air dispenser. Also, known coating methods (e.g., dip coating, spray coating, bar coater coating, gravure coating, reverse gravure coating, and spin coater coating) and known printing methods (e.g., lithographic printing, carton printing, metal printing, offset printing, screen printing, gravure printing, flexographic printing, and inkjet printing) can be used.

[0060] (Curing conditions) The resin composition can be cured by heating it at a temperature of, for example, 60 to 150° C. The heating temperature is preferably 65 to 120° C., more preferably 70 to 100° C. The heating time is preferably 0.25 to 4 hours, more preferably 0.5 to 2 hours.

[0061] <Application> This resin composition has low elasticity, excellent low-temperature curing properties, and a long pot life. From these perspectives, this resin composition can be used, for example, in the field of flexible hybrid electronics (FHE), and is suitable for precision components such as electronic components and semiconductor circuits used in optical components and semiconductor devices. More specifically, conductive materials such as conductive adhesives prepared from this resin composition containing conductive particles, or cured products obtained by curing this resin composition, can be used as component mounting materials, encapsulants for component protection, or reinforcing insulating materials. [Example]

[0062] A resin composition according to an embodiment of the present disclosure will be described below, although the present embodiment is not limited to the following examples.

[0063] The following materials were used to prepare the resin compositions of the Examples and Comparative Examples. <Material> 1. (A) Radical polymerizable curable resin (A1) Urethane acrylate oligomer (A1-1) Urethane acrylate oligomer "MBA-2CZ": molecular weight 1,600 (Negami Chemical Industrial Co., Ltd.) (A1-2) Urethane acrylate oligomer "UN-333": molecular weight 3,000 (Negami Chemical Industrial Co., Ltd.) (A1-3) Urethane acrylate oligomer "UN-6200": molecular weight 6,500 (Negami Chemical Industrial Co., Ltd.) (A1-4) Urethane acrylate oligomer "UV-3200B": molecular weight 10,000 (Mitsubishi Chemical Corporation) (A1-5) Urethane acrylate oligomer "UN-6304": molecular weight 13,000 (Negami Chemical Industrial Co., Ltd.) (A1-6) Urethane acrylate oligomer "UV-3000B": molecular weight 18,000 (Mitsubishi Chemical Corporation) (A1-7) Urethane acrylate oligomer "UN-3320HA": molecular weight 1,500 (Negami Chemical Industrial Co., Ltd.) (A1-8) Urethane acrylate oligomer "UN6207": molecular weight 27,000 (Negami Chemical Industrial Co., Ltd.)

[0064] (A2) Acrylate Monomer (A2-1) Acrylic resin "Light Acrylate PO-A" (Kyoeisha Chemical Co., Ltd.) (A2-2) Acrylic resin "Light Acrylate IB-XA" (Kyoeisha Chemical Co., Ltd.)

[0065] (A3) Bismaleimide resin (A3-1) Bismaleimide resin "BMI-1500" (liquid, dimer acid modified) (Designer Molecules Inc.)

[0066] (B) Radical polymerization initiator (B-1) Peroxydicarbonate "Perloyl TCP": 10-hour half-life temperature 40.8°C (NOF Corporation) (B-2) Dicumyl peroxide "Percumyl D": 10-hour half-life temperature 119.5°C (NOF Corporation)

[0067] (C) Radical polymerization inhibitor (C-1) Nitrosophenylhydroxyamine aluminum salt (NNAS) "Q1301" (Fujifilm Wako Pure Chemical Industries, Ltd.) (C-2) Hydroquinone "HQ" (Fujifilm Wako Pure Chemical Industries, Ltd.) (C-3) 2,2,6,6-tetramethyl-1-piperidinyloxy "TEMPO" (Koei Chemical Industry Co., Ltd.)

[0068] (D1) Conductive particles (D1-1) Silver powder "EA79613": average particle size 7 μm (Metalor Technologies) (D1-2) Silver powder "K79121P": average particle size 1 μm (Metalor Technologies)

[0069] (D2) Insulating particles (D2-1) Silica "SE5200SEE": average particle size 2 μm (Admatechs Co., Ltd.) (D2-2) Silica "TS720": average particle size 0.3 μm (Capot Co., Ltd.)

[0070] <Production of Examples and Comparative Examples> The materials were blended in the blending ratios shown in Tables 1 to 3 below, and stirred and mixed using a three-roll mill to produce the resin compositions of Examples 1 to 19 and Comparative Examples 1 to 5.

[0071] [Table 1]

[0072] [Table 2]

[0073] [Table 3]

[0074] (physical properties) The physical properties of the resin compositions of the Examples and Comparative Examples were measured and evaluated by the methods described below.

[0075] (curable at 70℃) The solidification of the sample portion of the test piece for which die shear strength was measured was confirmed by visual inspection and by touch. When solidification of the sample portion of the test piece could be confirmed by visual inspection and by touch, it was given an "A" rating. When solidification of the sample portion of the test piece could not be confirmed by visual inspection or by touch, it was given a "B" rating. Whether or not the sample portion of the test piece had hardened at 70°C can also be evaluated by the die shear strength, which will be described later.

[0076] (viscosity) The viscosity of each resin composition was measured at 10 rpm using a Brookfield RVT viscometer (spindle: SC4-14 spindle, measurement temperature: 25°C). If the measured viscosity was 100 (Pa s) or less, the resin composition was evaluated as passing. The results are shown in Tables 1 to 3 above.

[0077] (die shear strength) A glass substrate was prepared as the substrate, and a 3 mm square Si die was prepared as the die. Each resin composition was printed onto the glass substrate using a polyimide film stencil (thickness: 120 μm) with a φ2 mm hole. The 3 mm square Si die was then mounted, and curing was carried out at 70°C for 60 minutes in an air convention oven. In this way, a sample for measuring die shear strength was prepared. The die shear strength was measured at room temperature using a Nordson DAGE benchtop strength tester (model number: 4000PLUS-CART-S200KG). For each example and comparative example, 10 die shear strength measurement samples were measured. The arithmetic mean value of the 10 measured values ​​was defined as the die shear strength. 2 ) or more, the resin composition was evaluated as passing. The results are shown in Tables 1 to 3. Note that measurement was not possible for Comparative Example 4.

[0078] (Room temperature elastic modulus) Each resin composition was applied to a glass slide attached with Teflon tape (Teflon is a registered trademark) so that the film thickness upon curing would be 200±50 μm, forming a coating film. The coating film was then cured by leaving it in an air convention oven at 70°C for 60 minutes. The cured coating film was peeled off from the glass slide attached with the Teflon tape. Test pieces having the specified dimensions (40 mm × 5 mm) were then cut from the cured coating film using a cutter. The cut edges were smoothed with sandpaper. The room temperature elastic modulus of this test piece was measured in accordance with JIS C6481 using a Hitachi High-Tech Science viscoelasticity measuring apparatus (DMA) (model: DMS7100) under the following conditions: deformation mode: tension, measurement mode: ramp, frequency: 10 Hz, strain amplitude: 5 μm, minimum tension / compression force: 50 mN, tension / compression force gain: 1.2, initial force amplitude value: 50 mN, movement waiting time: 8 seconds, and creep waiting time coefficient: 0, at 25°C. If the measured room temperature elastic modulus was 1.6 (GPa) or less, the resin composition was evaluated as passing. The results are shown in Tables 1 to 3 above. In Comparative Example 4, the room temperature elastic modulus could not be measured.

[0079] (pot life) The viscosity of the adhesive composition immediately after preparation (viscosity immediately after preparation) and the viscosity of the adhesive composition after standing at room temperature (25°C) for a predetermined time (standing time) (viscosity of adhesive composition) were measured at 10 rpm using a Brookfield RVT viscometer (spindle: SC4-14 spindle, measurement temperature: 25°C). The viscosity change of the adhesive composition was calculated as the viscosity increase ratio, where the viscosity immediately after preparation was taken as 1.0. A larger viscosity increase ratio indicates that the viscosity of the adhesive composition increases over time. Therefore, a large viscosity increase ratio indicates that the resin composition is approaching a state where it cannot be used as an adhesive. Conversely, a small viscosity increase ratio indicates that the viscosity does not change significantly over time. Therefore, it can be said that the resin composition maintains a usable state as an adhesive. In other words, a small viscosity increase ratio indicates that the resin composition has a long pot life. In the examples and comparative examples, the standing time until the viscosity increase ratio reaches 1.5 or more is shown. A resin composition that was left for 6 hours or longer was evaluated as passing.

[0080] (comprehensive evaluation) If all of the measurement results met the pass criteria, the resin composition was rated as "A." If even one of the measurement results did not meet the pass criteria, the resin composition was rated as "B." Also, "-" indicates that the test piece was not in a condition suitable for measurement. In each example, all measurement results met the pass criteria. In Comparative Example 1, the mass average molecular weight of the urethane acrylate oligomer (A1) used was small, so the room temperature modulus did not satisfy the pass standard. In Comparative Example 2, the mass average molecular weight of the urethane acrylate oligomer (A1) used was large, so a portion remained uncured when cured at 70° C. As a result, both the viscosity and the die shear strength did not satisfy the pass criteria. In Comparative Example 3, the resin composition did not contain the nitrosamine compound (C1), and therefore the pot life did not satisfy the acceptance criteria. In Comparative Example 4, the resin composition did not contain the nitrosamine compound (C1), and therefore the resin composition did not cure at 70° C. As a result, the die shear strength and room temperature modulus themselves could not be measured. In Comparative Example 5, the room temperature modulus did not satisfy the pass standard because (A1) urethane acrylate oligomer was not used.

[0081] These results confirm that a resin composition comprising (A) a radically polymerizable curable resin, (B) a radical polymerization initiator, and (C) a radical polymerization inhibitor, wherein the component (C) contains a (C1) nitrosamine compound, the component (A) contains an (A1) urethane acrylate oligomer, and the component (A1) has a mass average molecular weight of 1,600 or more and 20,000 or less, has low elasticity, excellent low-temperature curing properties, and a long pot life.

Claims

1. (A) a radically polymerizable curable resin; (B) a radical polymerization initiator; (C) a radical polymerization inhibitor; Including, The component (C) contains a nitrosamine compound (C1), The component (A) contains (A1) a urethane acrylate oligomer and (A3) a bismaleimide resin, The component (A1) has a mass average molecular weight of 1,600 or more and 20,000 or less. Resin composition.

2. (A) a radically polymerizable curable resin; (B) a radical polymerization initiator; (C) a radical polymerization inhibitor; Conductive particles made of metal; Including, The component (C) contains a nitrosamine compound (C1), The component (A) contains (A1) a urethane acrylate oligomer, The component (A1) has a mass average molecular weight of 1,600 or more and 20,000 or less. Resin composition.

3. A resin composition as described in claim 2, wherein the metal is silver or copper.

4. A resin composition described in claim 2 or 3, wherein the content of the conductive particles per 100 parts by mass of the resin composition is 50 parts by mass to 95 parts by mass.

5. (A) a radically polymerizable curable resin; (B) a radical polymerization initiator; (C) a radical polymerization inhibitor; Including, The component (C) contains a nitrosamine compound (C1), The component (A) contains (A1) a urethane acrylate oligomer, The component (A1) has a mass average molecular weight of 1,600 or more and 20,000 or less, Used as a conductive adhesive Resin composition.

6. (A) a radically polymerizable curable resin; (B) a radical polymerization initiator; (C) a radical polymerization inhibitor; Including, The component (C) contains a nitrosamine compound (C1), The component (A) contains (A1) a urethane acrylate oligomer, The component (A1) has a mass average molecular weight of 1,600 or more and 13,000 or less. A thermosetting resin composition.

7. The component (B) is contained in an amount of 0.1 parts by mass to 30 parts by mass per 100 parts by mass of the component (A), The component (B) contains an organic peroxide, The organic peroxide has a 10-hour half-life temperature of 165°C or less. The resin composition according to any one of claims 1 to 6.

8. The component (A) further contains a bismaleimide resin (A3). The resin composition according to any one of claims 2 to 6.

9. The component (A) further contains an acrylate monomer (A2). The resin composition according to any one of claims 1 to 8.

10. (A2) The acrylate monomer includes an acrylate monomer having a glass transition temperature (Tg) of 15°C or higher; The resin composition according to claim 9.

11. The component (A1) is contained in an amount of 5 parts by mass to 50 parts by mass per 100 parts by mass of the component (A), The resin composition according to any one of claims 1 to 10.

12. the mass ratio of the urethane acrylate oligomer (A1) to the acrylate monomer (A2) is 5:95 to 60:40; The resin composition according to any one of claims 9 to 11.

13. The component (C) is contained in an amount of 0.1 to 5 parts by mass per 100 parts by mass of the component (B), The resin composition according to any one of claims 1 to 12.

14. After standing at 70°C for 60 minutes, the room temperature elastic modulus is 0.01 Gpa to 1.6 Gpa. The resin composition according to any one of claims 1 to 13.

15. containing insulating particles, The resin composition according to any one of claims 1 to 14.

16. containing conductive particles, The resin composition according to claim 1, 5 or 6.

17. Used in flexible hybrid electronics applications, The resin composition according to any one of claims 1 to 16.

18. The resin composition according to any one of claims 1 to 4 or 6 is included. Conductive adhesive.

19. The method according to any one of claims 1 to 17, A cured product of the resin composition.

20. The conductive adhesive according to claim 18 or the cured product according to claim 19, Semiconductor device.

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