WO2018181803A1 - Curable resin composition, dry film, cured product and electronic component - Google Patents

Abstract

Provided are: a curable resin composition which enables the achievement of a cured product that is able to maintain low thermal expansion coefficient not only at normal temperature but also in a high temperature range exceeding 200°C during component mounting, while having low dielectric characteristics without deteriorating the other characteristics; a dry film which uses this curable resin composition; a cured product; and an electronic component. The present invention provides a curable resin composition which contains: a fine powder that is smaller than 100 nm at least in one dimension; and an active ester compound. The present invention also provides: a dry film which uses this curable resin composition; a cured product; and an electronic component.

Description

Curable resin composition, dry film, cured product and electronic component

The present invention relates to a curable resin composition, a dry film, a cured product, and an electronic component.

As electronic parts, there are a wiring board, an active part fixed to the wiring board, a passive part, and the like. There are some wiring boards that connect conductors and fix active parts, passive parts, etc. by applying conductor wiring to the insulating base material. Depending on the application, the insulating layer and the conductor layer may be multilayered or flexible. Insulating base materials may be used, which is an important electronic component in electronic equipment. Moreover, a wiring board is used also for a semiconductor package, and the curable resin composition for wiring boards and a dry film are used as an outer layer after mounting a wiring board or a semiconductor. Examples of the active component and the passive component include a transistor, a diode, a resistor, a coil, and a capacitor.

In recent years, with the miniaturization of electronic devices, the required characteristics for electronic components have become stricter. The wiring board has been required to have a higher density of wiring, and in order to ensure the reliability of the wiring and the component connection portion, the material of the wiring board is required to have low thermal expansion. Active parts and passive parts are also required to be downsized and highly integrated. Similarly, low thermal expansion has been required to ensure reliability.

As a technique for achieving low thermal expansion, for example, Patent Document 1 proposes a technique for obtaining a low thermal expansion coefficient by filling an inorganic filler into a resin.

JP 2001-72834 A

However, the material described in Patent Document 1 has a problem that in order to obtain a desired low thermal expansion coefficient, a large amount of an inorganic filler must be filled, resulting in poor physical properties of the cured product.
Furthermore, the present inventors say that the material described in Patent Document 1 has a large coefficient of thermal expansion in the temperature range at the time of component mounting exceeding 200 ° C., and is ineffective for ensuring reliability. I realized there was a new problem.

Accordingly, an object of the present invention is to provide a curable resin composition capable of obtaining a cured product capable of maintaining a low coefficient of thermal expansion even in a high temperature region during component mounting.
Another object of the present invention is to provide a dry film, a cured product, and an electronic component using the curable resin composition.

As a result of intensive studies, the present inventors have found that the above problems can be solved by using an active ester compound together with a fine powder having a dimension smaller than 100 nm, and have solved the present invention.

That is, the curable resin composition of the present invention is characterized in that it contains at least one fine powder having a one-dimensional dimension smaller than 100 nm (hereinafter also simply referred to as “fine powder”) and an active ester compound. is there. The curable resin composition of the present invention preferably further contains a filler.

The dry film of the present invention is characterized in that the curable resin composition has a resin layer formed by applying and drying on the film.

The cured product of the present invention is characterized in that the curable resin composition or the resin layer of the dry film is cured.

The electronic component of the present invention is characterized by comprising the above cured product.

Here, in the present invention, the fine powder is not particularly limited in shape, and may be in the form of fibers, scales, granules, etc., and “at least one dimension is less than 100 nm” It means that either one dimension, two dimensions or three dimensions is smaller than 100 nm. For example, in the case of a fibrous fine powder, those having a two-dimensional dimension smaller than 100 nm and having a remaining one-dimensional extension can be mentioned, and in the case of a flaky fine powder, one side is smaller than 100 nm and remains. In the case of a granular fine powder, those having a dimension smaller than 100 nm are exemplified.
In the present invention, the one-dimensional, two-dimensional and three-dimensional sizes of the fine powder are determined by measuring the fine powder with SEM (Scanning Electron Microscope) or TEM (Transmission Electron Microscope), It can be observed and measured with an AFM (Atomic Force Microscope) or the like.
For example, in the case of a scale-like fine powder, the average value of the thickness which is the smallest one-dimensional is measured, and this average thickness is made smaller than 100 nm. Specifically, a line is drawn on the diagonal line of the micrograph, and 12 fine powders in the vicinity of which the thickness can be measured are randomly extracted to obtain the thickest fine powder and the thinnest fine powder. After removal, the remaining 10 thicknesses are measured, and the average value is assumed to be smaller than 100 nm.
In the case of fibrous fine powder, the average value of the two-dimensional average fiber diameter is measured, and this average fiber diameter is set to be smaller than 100 nm. Specifically, a line is drawn on the diagonal line of the micrograph, and 12 fine powders in the vicinity thereof are randomly extracted to remove the fine powder having the thickest fiber diameter and the thinnest fiber diameter, and then the remaining 10 The fiber diameter of the points is measured, and the average value is assumed to be smaller than 100 nm.
In the case of granular fine powder, the average value of the particle diameter is measured, and this average particle diameter is set to be smaller than 100 nm. Specifically, a line is drawn on the diagonal line of the micrograph, and 12 fine powders in the vicinity thereof are randomly extracted to remove the fine powder having the largest particle size and the smallest particle size, and then remain 10 The particle size of the points is measured and the average value is less than 100 nm.
In a fine powder having a spread to other dimensions such as a fiber shape or a scale shape, the spread is, for example, less than 1000 nm, preferably less than 650 nm, and more preferably less than 450 nm. If the spread is less than 1000 nm, the reinforcing effect by the interaction between the fine powders can be effectively obtained.

ADVANTAGE OF THE INVENTION According to this invention, the curable resin composition which can obtain the hardened | cured material which can maintain a low thermal expansion coefficient also in the high temperature area | region at the time of component mounting can be provided.
Moreover, according to this invention, the dry film, hardened | cured material, and electronic component using the said curable resin composition can be provided.

It is a fragmentary sectional view which shows the example of 1 structure of the multilayer printed wiring board which concerns on an example of the electronic component of this invention. It is explanatory drawing which shows the test board | substrate used in the Example.

Hereinafter, embodiments of the present invention will be described in detail.
The curable resin composition of the present invention includes a fine powder and an active ester compound.
By adopting such a configuration, it is possible to maintain a low coefficient of thermal expansion even in the temperature range at which the component is mounted such that the temperature exceeds 200 ° C. Further, by reducing the relative permittivity and the dielectric loss tangent, low dielectric properties can be obtained. An electronic component can be obtained.

[Fine powder]
The fine powder used in the present invention is a powder having at least one dimension smaller than 100 nm, and as described above, not only a fine spherical shape but also a fiber having a cross-sectional diameter smaller than 100 nm. Moreover, the sheet-like (scale-like) thing etc. whose thickness is smaller than 100 nm are included. Such a fine powder has a much larger surface area per unit mass and a higher proportion of atoms exposed on the surface than those in which all three dimensions are 100 nm or more. Therefore, it is considered that the reinforcing effect is exhibited by the interaction that the fine powder attracts each other, and the thermal expansibility is lowered. This effect is remarkably manifested among hydrophilic fine powders.

The fine powder may be any particle that is at least one dimension smaller than 100 nm, and the material is not particularly limited. Examples of the fine powder include carbon-based materials such as fullerene, single-walled carbon nanotubes, and multi-walled carbon nanotubes, and inorganic materials such as silver, gold, iron, nickel, titanium oxide, cerium oxide, zinc oxide, silica, and aluminum hydroxide. Isolate only crystal parts from organic materials processed into nanotubes, nanowires, nanosheets, minerals such as clay, smectite, bentonite, fine cellulose fibers from plant fibers and cellulose raw materials Fine chitin obtained by opening chitin obtained from cellulose nanocrystal particles, crustaceans and the like, and fine chitosan treated with alkali, and two or more of them may be used in combination. Among these, examples of hydrophilic fine powders include metal oxide fine particles such as titanium oxide, metal hydroxide fine particles such as aluminum hydroxide, mineral fine particles such as clay, fine cellulose fibers, and fine chitin. . Among such fine powders, in particular, fine cellulose fibers are desirable from the viewpoint of reinforcing effect and ease of handling. Cellulose nanocrystal particles are also preferred.

When a hydrophilic fine powder is used as the fine powder as described above, it is preferable to subject the particles to a hydrophobic treatment or a surface treatment using a coupling agent. For such treatment, a known and conventional method suitable for fine powder can be used.

The blending amount of the fine powder in the present invention is preferably 0.04 to 64% by mass, more preferably 0.08 to 30% by mass, and still more preferably, based on the total amount of the composition excluding the solvent. 0.1 to 10% by mass. When the blending amount of the fine powder is 0.04% by mass or more, the effect of reducing the linear expansion coefficient can be favorably obtained. On the other hand, in the case of 64 mass% or less, film forming property improves.

(Fine cellulose fiber)
Among the fine powders according to the present invention, fine cellulose fibers can be obtained as follows, but are not limited to these.

As raw materials for fine cellulose fibers, use pulp made from natural plant fiber materials such as wood, hemp, bamboo, cotton, jute, kenaf, beet, agricultural waste, cloth, regenerated cellulose fibers such as rayon and cellophane, etc. Among them, pulp is particularly preferable. As pulp, chemical pulp such as kraft pulp and sulfite pulp, semi-chemical pulp, chemi-ground pulp, chemimechanical pulp, obtained by pulping plant raw materials chemically or mechanically, or a combination of both, Thermomechanical pulp, chemithermomechanical pulp, refiner mechanical pulp, groundwood pulp, deinked wastepaper pulp, magazine wastepaper pulp, corrugated wastepaper pulp and the like mainly composed of these plant fibers can be used. Among them, various kraft pulps derived from conifers having strong fiber strength, for example, softwood unbleached kraft pulp, softwood oxygen bleached unbleached kraft pulp, and softwood bleached kraft pulp are particularly suitable.

The raw material is mainly composed of cellulose, hemicellulose and lignin, and the content of lignin is usually about 0 to 40% by mass, particularly about 0 to 10% by mass. About these raw materials, the removal of a lignin thru | or a bleaching process can be performed as needed, and the amount of lignin can be adjusted. The lignin content can be measured by the Klason method.

In the cell wall of a plant, cellulose molecules are not a single molecule but regularly agglomerate to form a microfibril (fine cellulose fiber) having crystallinity, which is a basic skeletal substance of the plant. ing. Therefore, in order to produce fine cellulose fibers from the above raw materials, the above raw materials are beaten or pulverized, treated with high temperature and high pressure steam, treated with phosphate, etc., and the cellulose fibers are oxidized using an N-oxyl compound as an oxidation catalyst. By performing the treatment or the like, a method of unraveling the fiber to nano size can be used.

Among the above, the beating or pulverization treatment is a method of obtaining fine cellulose fibers by directly applying force to the raw materials such as pulp, mechanically beating or pulverizing, and unraveling the fibers. More specifically, for example, pulp fibers or the like are mechanically treated with a high-pressure homogenizer or the like, and cellulose fibers that have been loosened to a fiber diameter of about 0.1 to 10 μm are made into an aqueous suspension of about 0.1 to 3% by mass. Further, by repeatedly grinding or crushing this with a grinder or the like, fine cellulose fibers having a fiber diameter of about 10 to 100 nm can be obtained.

The grinding or crushing treatment can be performed using, for example, a grinder “Pure Fine Mill” manufactured by Kurita Machine Seisakusho. This grinder is a stone mill that pulverizes raw materials into ultrafine particles by impact, centrifugal force and shearing force generated when the raw material passes through the gap between the upper and lower two grinders. Shearing, grinding, atomization Dispersion, emulsification and fibrillation can be performed simultaneously. Further, the above grinding or crushing treatment can also be carried out using an ultrafine grinding machine “Supermass colloider” manufactured by Masuko Sangyo Co., Ltd. The Super Mass Collider is an attritor that enables ultra-fine atomization that feels like melting beyond the mere grinding area. The super mass collider is a stone mill type ultrafine grinding machine composed of two top and bottom non-porous grindstones whose spacing can be freely adjusted. The upper grindstone is fixed and the lower grindstone rotates at high speed. The raw material thrown into the hopper is fed into the gap between the upper and lower grinding stones by centrifugal force, and the raw material is gradually crushed by the strong compression, shearing, rolling frictional force, etc. generated there, and is made into ultrafine particles.

The high-temperature high-pressure steam treatment is a method for obtaining fine cellulose fibers by unraveling the fibers by exposing the raw materials such as pulp to high-temperature high-pressure steam.

Furthermore, the treatment with the phosphate or the like is performed by phosphating the surface of the raw material such as the pulp to weaken the binding force between the cellulose fibers, and then performing a refiner treatment to unravel the fibers and finely This is a treatment method for obtaining cellulose fibers. For example, the raw materials such as pulp are immersed in a solution containing 50% by mass of urea and 32% by mass of phosphoric acid, and the solution is sufficiently soaked between cellulose fibers at 60 ° C., and then heated at 180 ° C. After proceeding with phosphorylation and washing with water, it was hydrolyzed in a 3% by mass aqueous hydrochloric acid solution at 60 ° C. for 2 hours, washed again with water, and then further washed with a 3% by mass aqueous sodium carbonate solution. Fine cellulose fibers can be obtained by completing phosphorylation by treating at room temperature for about 20 minutes and defibrating the treated product with a refiner.

The treatment for oxidizing cellulose fibers using the N-oxyl compound as an oxidation catalyst is a method for obtaining fine cellulose fibers by oxidizing the raw materials such as pulp and then refining them.

First, an aqueous dispersion is prepared by dispersing natural cellulose fibers in about 10 to 1000 times (mass basis) of water on an absolute dry basis using a mixer or the like. Examples of the natural cellulose fiber used as a raw material for the fine cellulose fiber include, for example, wood pulp such as softwood pulp and hardwood pulp, non-wood pulp such as straw pulp and bagasse pulp, cotton pulp such as cotton lint and cotton linter, Examples include bacterial cellulose. These may be used individually by 1 type, or may be used in combination of 2 or more types as appropriate. Further, these natural cellulose fibers may be subjected to a treatment such as beating in order to increase the surface area in advance.

Next, natural cellulose fibers are oxidized in the aqueous dispersion using an N-oxyl compound as an oxidation catalyst. Examples of such N-oxyl compounds include TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl), 4-carboxy-TEMPO, 4-acetamido-TEMPO, 4-amino-TEMPO, 4 -Dimethylamino-TEMPO, 4-phosphonooxy-TEMPO, 4-hydroxy TEMPO, 4-oxy TEMPO, 4-methoxy TEMPO, 4- (2-bromoacetamido) -TEMPO, 2-azaadamantane N-oxyl, etc. TEMPO derivatives having various functional groups at the C4 position can be used. As the addition amount of these N-oxyl compounds, a catalytic amount is sufficient, and it can usually be in a range of 0.1 to 10% by mass with respect to natural cellulose fiber on an absolute dry basis.

In the oxidation treatment of the natural cellulose fiber, an oxidizing agent and a co-oxidizing agent are used in combination. Examples of the oxidizing agent include halous acid, hypohalous acid and perhalogenic acid and salts thereof, hydrogen peroxide, perorganic acid, among which sodium hypochlorite and sodium hypobromite. Alkali metal hypohalites such as are preferred. Further, as the co-oxidant, for example, an alkali metal bromide such as sodium bromide can be used. The amount of the oxidizing agent used is usually in the range of about 1 to 100% by mass based on the absolute dry standard relative to the natural cellulose fiber, and the amount of the co-oxidant used is usually based on the absolute dry standard relative to the natural cellulose fiber. Is about 1 to 30% by mass.

In the oxidation treatment of the natural cellulose fiber, it is preferable to maintain the pH of the aqueous dispersion in the range of 9 to 12 from the viewpoint of efficiently proceeding the oxidation reaction. Further, the temperature of the aqueous dispersion during the oxidation treatment can be arbitrarily set within the range of 1 to 50 ° C., and the reaction is possible even at room temperature without temperature control. The reaction time can be in the range of 1 to 240 minutes. In addition, a penetrant can be added to the aqueous dispersion in order to allow the drug to penetrate into the inside of the natural cellulose fiber and introduce more carboxyl groups into the fiber surface. Examples of the penetrating agent include anionic surfactants such as carboxylate, sulfate ester salt, sulfonate salt, and phosphate ester salt, and nonionic surfactants such as polyethylene glycol type and polyhydric alcohol type. .

After the oxidation treatment of the natural cellulose fiber, it is preferable to carry out a purification treatment to remove impurities such as unreacted oxidant and various by-products contained in the aqueous dispersion prior to refinement. Specifically, for example, a technique of repeatedly washing and filtering the oxidized natural cellulose fiber can be used. The natural cellulose fiber obtained after the refining treatment is usually subjected to a refining treatment in a state impregnated with an appropriate amount of water. However, if necessary, the natural cellulose fiber may be dried to obtain a fibrous or powdery form.

Next, the refinement of the natural cellulose treatment is performed in a state where the natural cellulose fibers purified as desired are dispersed in a solvent such as water. The solvent as a dispersion medium used in the micronization treatment is usually preferably water, but if desired, alcohols (methanol, ethanol, isopropanol, isobutanol, sec-butanol, tert-butanol, methyl cellosolve, ethyl cellosolve, Ethylene glycol, glycerin, etc.), ethers (ethylene glycol dimethyl ether, 1,4-dioxane, tetrahydrofuran, etc.), ketones (acetone, methyl ethyl ketone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, etc.), etc. A water-soluble organic solvent may be used, or a mixture thereof may be used. The solid content concentration of the natural cellulose fiber in the dispersion of these solvents is preferably 50% by mass or less. When the solid content concentration of the natural cellulose fiber exceeds 50% by mass, extremely high energy is required for dispersion, which is not preferable. Refinement of natural cellulose treatment includes low-pressure homogenizers, high-pressure homogenizers, grinders, cutter mills, ball mills, jet mills, beating machines, disintegrators, short-screw extruders, twin-screw extruders, ultrasonic agitators, household juicer mixers, etc. This can be done using a dispersing device.

The fine cellulose fiber obtained by the refining treatment can be in the form of a suspension in which the solid content concentration is adjusted or in the form of a dried powder, as desired. Here, in the case of a suspension, only water may be used as a dispersion medium, and water and other organic solvents, for example, alcohols such as ethanol, surfactants, acids, bases, etc. A mixed solvent may be used.

By the oxidation treatment and refinement treatment of the natural cellulose fiber, the hydroxyl group at the C6 position of the structural unit of the cellulose molecule is selectively oxidized to a carboxyl group via an aldehyde group, and the content of the carboxyl group is 0.1. It is possible to obtain highly crystalline fine cellulose fibers having a predetermined number average fiber diameter, composed of cellulose molecules of ˜3 mmol / g. This highly crystalline fine cellulose fiber has a cellulose I-type crystal structure. This means that the fine cellulose fibers are those obtained by surface-oxidizing naturally-derived cellulose molecules having an I-type crystal structure. That is, natural cellulose fibers have a high-order solid structure formed by a bundle of fine fibers called microfibrils produced in the process of biosynthesis, and a strong cohesive force between the microfibrils (between surfaces). The fine cellulose fiber is obtained by weakening the hydrogen bond) by introduction of an aldehyde group or a carboxyl group by oxidation treatment, and further through a refinement treatment. By adjusting the conditions of the oxidation treatment, the content of the carboxyl group is increased or decreased, the polarity is changed, or by the electrostatic repulsion or refinement treatment of the carboxyl group, the average fiber diameter or average fiber length of the fine cellulose fibers, The average aspect ratio can be controlled.

That the natural cellulose fiber has a type I crystal structure is typical at two positions in the vicinity of 2θ = 14 to 17 ° and 2θ = 22 to 23 ° in a diffraction profile obtained by measurement of a wide-angle X-ray diffraction image. It can be identified from having a typical peak. In addition, the introduction of a carboxyl group into the cellulose molecule of the fine cellulose fiber means that the absorption due to the carbonyl group (1608 cm ⁻¹ ) in the total reflection infrared spectroscopic spectrum (ATR) in the sample from which moisture has been completely removed. This can be confirmed by the presence of the vicinity. In the case of a carboxyl group (COOH), there is an absorption at 1730 cm ⁻¹ in the above measurement.

In addition, since halogen atoms are attached or bonded to the natural cellulose fiber after the oxidation treatment, dehalogenation treatment can be performed for the purpose of removing such residual halogen atoms. The dehalogenation treatment can be performed by immersing the oxidized natural cellulose fiber in a hydrogen peroxide solution or an ozone solution.

Specifically, for example, the oxidized natural cellulose fiber is added to a hydrogen peroxide solution having a concentration of 0.1 to 100 g / L in a bath ratio of about 1: 5 to 1: 100, preferably 1:10 to 1. : Immerse under conditions of about 60 (mass ratio). In this case, the concentration of the hydrogen peroxide solution is preferably 1 to 50 g / L, and more preferably 5 to 20 g / L. The pH of the hydrogen peroxide solution is preferably 8 to 11, more preferably 9.5 to 10.7.

In addition, the amount [mmol / g] of the carboxyl group in the cellulose with respect to the mass of the fine cellulose fiber contained in the aqueous dispersion can be evaluated by the following method. That is, 60 ml of a 0.5 to 1% by mass aqueous dispersion of a fine cellulose fiber sample whose dry mass was precisely weighed in advance was prepared, and the pH was adjusted to about 2.5 with a 0.1 M aqueous hydrochloric acid solution. An aqueous sodium hydroxide solution is dropped until the pH is about 11, and the electrical conductivity is measured. From the amount (V) of sodium hydroxide consumed in the weak acid neutralization stage where the change in electrical conductivity is slow, the functional group amount can be determined using the following formula. This amount of functional groups indicates the amount of carboxyl groups.
Functional group amount [mmol / g] = V [ml] × 0.05 / fine cellulose fiber sample [g]

In addition, the fine cellulose fiber used in the present invention may be chemically modified and / or physically modified to enhance functionality. Here, as the chemical modification, a functional group is added by acetalization, acetylation, cyanoethylation, etherification, isocyanateation, etc., or inorganic substances such as silicate and titanate are combined by chemical reaction or sol-gel method, Or it can carry out by the method of coat | covering. Examples of the chemical modification method include a method in which fine cellulose fibers formed into a sheet are immersed in acetic anhydride and heated. In addition, fine cellulose fibers obtained by oxidizing cellulose fibers using an N-oxyl compound as an oxidation catalyst modify amine compounds, quaternary ammonium compounds, etc. with ionic bonds or amide bonds at the carboxyl groups in the molecules. A method is mentioned.
Physical modification methods include, for example, metal or ceramic raw materials such as vacuum vapor deposition, ion plating, sputtering and other physical vapor deposition methods (PVD methods), chemical vapor deposition methods (CVD methods), electroless plating, and electroplating. Examples of the method include coating by a method. These modifications may be before the treatment or after the treatment.

The number average fiber diameter of the fine cellulose fiber used in the present invention is preferably 3 nm or more and smaller than 100 nm. Since the minimum diameter of the fine cellulose fiber monofilament is 3 nm, it cannot be produced substantially less than 3 nm, and when it exceeds 100 nm, it is necessary to add excessively in order to obtain the desired effect of the present invention. The film forming property is deteriorated. The number average fiber diameter of the fine cellulose fibers can be measured according to the method for measuring the size of the fine powder described above.

(Cellulose nanocrystal particles)
In the present invention, the cellulose nanocrystal particles are those obtained by hydrolyzing a cellulose raw material with a high concentration of mineral acid (hydrochloric acid, sulfuric acid, hydrobromic acid, etc.) and isolating only the crystalline portion except the non-crystalline portion. Any particle can be used. Specifically, the cellulose nanocrystal particles are made of cellulose raw material at a concentration of 60 wt% or more with a strong acid of 7 wt% or more, preferably 9 wt% or more, and more preferably a strong acid that can be easily concentrated, such as sulfuric acid. It is a crystal body which does not contain an amorphous part obtained by performing hydrolysis. By using cellulose nanocrystal particles as a fine powder, a cured product having excellent characteristics such as toughness and heat resistance is obtained while maintaining a low coefficient of thermal expansion even in a temperature range when mounting a component exceeding 200 ° C. A curable resin composition having excellent pot life can be provided.

The size of the cellulose nanocrystal particles is preferably 3 to 70 nm in average crystal width and 100 to 500 nm in average crystal length, more preferably 3 to 50 nm in average crystal width, 100 to 400 nm in average crystal length, More preferably, the average crystal width is 3 to 10 nm and the average crystal length is 100 to 300 nm. Here, the crystal width refers to the length of the short side of the particle, and the crystal length refers to the length of the long side of the particle. Such cellulose nanocrystal particles have a much larger surface area per unit mass than those having a larger width or length, and the ratio of atoms exposed on the surface increases. Therefore, it is considered that the reinforcing effect is exhibited by the interaction that the cellulose nanocrystal particles attract each other, and the thermal expansibility is lowered.

Here, the size (average crystal width, average crystal length) of the cellulose nanocrystal particles is determined by SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope), AFM (Atomic Force Microscopy). An atomic force microscope) or the like.
Specifically, a line is drawn on the diagonal line of the micrograph, and 12 particles that are in the vicinity and whose size can be measured are randomly extracted to remove the largest and smallest particles, and then remain. The size (crystal width, crystal length) of 10 points was measured, and the average value of each was the average crystal width and average crystal length of the cellulose nanocrystal particles.

As the cellulose nanocrystal particles, two or more types having different cellulose materials may be used in combination.

Such cellulose nanocrystal particles are preferably subjected to a hydrophobic treatment, a surface treatment using a coupling agent, and the like. Such treatment can be performed by a known and conventional method suitable for cellulose nanocrystal particles.

Here, examples of the cellulose raw material include paper pulp, cotton pulp such as cotton linter and cotton lint, non-wood pulp such as hemp, straw and bagasse, cellulose isolated from sea squirts and seaweeds, and the like. There is no particular limitation. Among these, paper pulp is preferable in terms of availability, and cotton and sea squirts are preferable in terms of being able to produce a CNC having higher heat resistance.
Examples of papermaking pulp include hardwood kraft pulp and softwood kraft pulp.
Examples of hardwood kraft pulp include bleached kraft pulp (LBKP), unbleached kraft pulp (LUKP), and oxygen bleached kraft pulp (LOKP).
Examples of softwood kraft pulp include bleached kraft pulp (NBKP), unbleached kraft pulp (NUKP), and oxygen bleached kraft pulp (NOKP).
Other examples include chemical pulp, semi-chemical pulp, mechanical pulp, non-wood pulp, and deinked pulp made from waste paper. Examples of chemical pulp include sulfite pulp (SP) and soda pulp (AP). Semi-chemical pulp includes semi-chemical pulp (SCP), chemiground wood pulp (CGP), and the like. Examples of mechanical pulp include groundwood pulp (GP) and thermomechanical pulp (TMP, BCTMP). Non-wood pulp includes those made from cocoon, cocoon, hemp, kenaf and the like.
Such a cellulose raw material may be used individually by 1 type, and may be used in mixture of 2 or more types. In addition, cellulose nanofibers (hereinafter also simply referred to as “CNF”) produced by a mechanical fibrillation method, a phosphoric acid esterification method, a TEMPO oxidation method, or the like may be used as a cellulose raw material.

Next, the hydrolysis of the cellulose raw material as described above is carried out, for example, by treating an aqueous suspension or slurry containing the cellulose raw material with sulfuric acid, hydrochloric acid, hydrobromic acid or the like, or treating the cellulose raw material as it is with sulfuric acid, hydrochloric acid, odor. It can be performed by suspending in an aqueous solution of hydrofluoric acid or the like. In particular, when pulp is used as the cellulose raw material, it is preferable to perform a hydrolysis treatment after forming a cotton-like fiber using a cutter mill, a pin mill, or the like from the viewpoint that a uniform hydrolysis treatment can be performed.
In such a hydrolysis treatment, the temperature condition is not particularly limited, but may be, for example, 25 to 90 ° C. Further, the conditions for the hydrolysis treatment time are not particularly limited, but may be, for example, 10 to 120 minutes.
The cellulose nanocrystal particles obtained by hydrolyzing the cellulose raw material in this way can be neutralized using an alkali such as sodium hydroxide, for example.

The cellulose nanocrystal particles thus obtained can be atomized as necessary. In this atomization process, a processing apparatus and a processing method are not particularly limited.
As the atomization processing device, for example, a grinder (stone mortar-type pulverizer), a high-pressure homogenizer, an ultra-high pressure homogenizer, a high-pressure collision type pulverizer, a ball mill, a bead mill, a disk type refiner, a conical refiner, a twin-screw kneader, a vibration mill, a high-speed mill A homomixer under rotation, an ultrasonic disperser, a beater, or the like can be used.

During the atomization treatment, it is preferable to dilute the cellulose nanocrystal particles in water or an organic solvent alone or in combination to form a slurry, but there is no particular limitation. Preferable organic solvents include alcohols, ketones, ethers, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), and the like. The dispersion medium may be one type or two or more types. Further, the dispersion medium may contain a solid content other than cellulose nanocrystal particles, for example, urea having hydrogen bonding properties.

Further, the cellulose nanocrystal particles used in the present invention may be chemically modified and / or physically modified to enhance functionality. Here, as the chemical modification, a functional group is added by acetalization, acetylation, cyanoethylation, etherification, isocyanateation, etc., or inorganic substances such as silicate and titanate are combined by chemical reaction or sol-gel method, Or it can carry out by the method of coat | covering. Physical modification can be performed by plating or vapor deposition.

[Active ester compound]
An active ester compound may be used individually by 1 type, or may use 2 or more types together. Although it does not restrict | limit especially as an active ester compound, The thing which has 2 or more of active ester groups in 1 molecule is preferable. The active ester compound can generally be obtained by a condensation reaction between one or more of a carboxylic acid compound and a thiocarboxylic acid compound and one or more of a hydroxy compound and a thiol compound. Examples of the active ester compound include dicyclopentadienyl diphenol ester compound, bisphenol A diacetate, diphenyl phthalate, diphenyl terephthalate, and bis [4- (methoxycarbonyl) phenyl terephthalate].

The compounding amount of the active ester compound is preferably 0.5% by mass or more and 80% by mass or less, more preferably 1% by mass or more and 40% by mass or less, and still more preferably 1.5% by mass with respect to the total amount of the composition excluding the solvent. The mass is 30% by mass or more. When the compounding quantity of the said active ester compound is 0.5 mass% or more, a low thermal expansion coefficient can be ensured favorable. On the other hand, in the case of 80 mass% or less, curability improves.

In the present invention, if desired, a curable resin such as a thermosetting resin other than the active ester compound can be used in combination.

(Thermosetting resin)
The thermosetting resin may be any resin that is cured by heating and exhibits electrical insulation. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol E type epoxy resin, bisphenol M type epoxy resin, bisphenol P type epoxy resin, bisphenol type epoxy resin such as bisphenol Z type epoxy resin, bisphenol A novolac type epoxy resin, phenol novolac type epoxy resin, novolac type epoxy resin such as cresol novolac epoxy resin, biphenyl type epoxy Resin, biphenyl aralkyl type epoxy resin, aryl alkylene type epoxy resin, tetraphenylol ethane type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type Poxy resin, norbornene type epoxy resin, adamantane type epoxy resin, fluorene type epoxy resin, glycidyl methacrylate copolymer epoxy resin, cyclohexyl maleimide and glycidyl methacrylate copolymer epoxy resin, epoxy modified polybutadiene rubber derivative, CTBN modified epoxy Resin, trimethylolpropane polyglycidyl ether, phenyl-1,3-diglycidyl ether, biphenyl-4,4′-diglycidyl ether, 1,6-hexanediol diglycidyl ether, diglycidyl ether of ethylene glycol or propylene glycol, Sorbitol polyglycidyl ether, tris (2,3-epoxypropyl) isocyanurate, triglycidyl tris (2-hydroxyethyl) isocyanate Resol type phenol resins such as novolak type phenol resins such as nurate, phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, unmodified resole phenol resin, oil modified resole phenol resin modified with tung oil, linseed oil, walnut oil, etc. Phenol resin such as phenoxy resin, urea (urea) resin, triazine ring-containing resin such as melamine resin, unsaturated polyester resin, bismaleimide resin, diallyl phthalate resin, silicone resin, resin having benzoxazine ring, norbornene resin, Examples include cyanate resins, isocyanate resins, urethane resins, benzocyclobutene resins, maleimide resins, bismaleimide triazine resins, polyazomethine resins, and thermosetting polyimides.

In addition, when the resin composition of the present invention is used as an alkali development type photo solder resist that can be developed with an alkaline aqueous solution, it is also preferable to use a carboxyl group-containing resin.

(Carboxyl group-containing resin)
As the carboxyl group-containing resin, any of a photosensitive carboxyl group-containing resin having at least one photosensitive unsaturated double bond and a carboxyl group-containing resin having no photosensitive unsaturated double bond can be used. However, it is not limited to a specific one. As the carboxyl group-containing resin, in particular, the resins listed below can be suitably used.
(1) A carboxyl group-containing resin obtained by copolymerization of an unsaturated carboxylic acid and a compound having an unsaturated double bond, and a carboxyl group-containing resin having a molecular weight and an acid value adjusted by modifying it.
(2) A photosensitive carboxyl group-containing resin obtained by reacting a carboxyl group-containing (meth) acrylic copolymer resin with a compound having an oxirane ring and an ethylenically unsaturated group in one molecule.
(3) An unsaturated monocarboxylic acid is reacted with a copolymer of a compound having one epoxy group and an unsaturated double bond in each molecule and a compound having an unsaturated double bond, and formed by this reaction. A photosensitive carboxyl group-containing resin obtained by reacting a secondary hydroxyl group with a saturated or unsaturated polybasic acid anhydride.
(4) After reacting a hydroxyl group-containing polymer with a saturated or unsaturated polybasic acid anhydride, a compound having one epoxy group and an unsaturated double bond in each molecule of the carboxylic acid produced by this reaction. Photosensitive hydroxyl group and carboxyl group-containing resin obtained by reaction.
(5) A photosensitive carboxyl group obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid and reacting a polybasic acid anhydride with some or all of the secondary hydroxyl groups produced by this reaction. Containing resin.
(6) A polyfunctional epoxy compound is reacted with a compound having one reactive group other than a hydroxyl group that reacts with two or more hydroxyl groups and an epoxy group in one molecule, and an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting the obtained reaction product with a polybasic acid anhydride.
(7) Obtained by reacting a reaction product of a resin having a phenolic hydroxyl group with an alkylene oxide or a cyclic carbonate with an unsaturated group-containing monocarboxylic acid, and reacting the resulting reaction product with a polybasic acid anhydride. Carboxyl group-containing photosensitive resin.
(8) A reaction product obtained by reacting a polyfunctional epoxy compound, a compound having at least one alcoholic hydroxyl group and one phenolic hydroxyl group in one molecule, and an unsaturated group-containing monocarboxylic acid. A carboxyl group-containing photosensitive resin obtained by reacting an anhydride group of a polybasic acid anhydride with an alcoholic hydroxyl group.

[Filler]
The resin composition of the present invention preferably further contains a filler other than the fine powder. Examples of fillers include barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, and aluminum nitride. It is done. Among these fillers, silica, especially spherical silica is preferable because it has a small specific gravity, can be blended in a high proportion in the composition, and is excellent in low thermal expansion. The average particle size of the filler is preferably 3 μm or less, more preferably 1 μm or less. The average particle size of the filler can be determined by a laser diffraction particle size distribution measuring device.

The blending amount of the filler is 1 to 90% by mass, preferably 2 to 80% by mass, more preferably 5 to 75% by mass in the total amount of the composition excluding the solvent. By making the compounding quantity of a filler into the said range, the coating-film performance of the hardened | cured material after hardening can be ensured favorably.

In the resin composition of the present invention, other conventional compounding components can be appropriately blended depending on the application. Examples of other commonly used ingredients include a curing catalyst, a colorant, and an organic solvent.

Curing catalysts include phenol compounds; imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- Imidazole derivatives such as (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzyl Examples include amines, amine compounds such as 4-methyl-N, N-dimethylbenzylamine, hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; phosphorus compounds such as triphenylphosphine, and the like. Examples of commercially available products include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (manufactured by Shikoku Kasei Kogyo Co., Ltd.), U-CAT3503N, U-CAT3502T, DBU, DBN, U-CATSA102, U- CAT5002 (manufactured by San Apro Co., Ltd.) and the like may be mentioned, and they may be used alone or in combination of two or more. Similarly, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6 S-triazine derivatives such as -diamino-S-triazine / isocyanuric acid adduct and 2,4-diamino-6-methacryloyloxyethyl-S-triazine / isocyanuric acid adduct can also be used.

In the present invention, a phenol compound is preferably used. Examples of the phenol compound include phenol novolak resin, alkylphenol novolak resin, triazine structure-containing novolak resin, bisphenol A novolak resin, dicyclopentadiene type phenol resin, zylock type phenol resin, copna resin, terpene modified phenol resin, polyvinylphenols, etc. These commonly known compounds such as phenolic compounds, naphthalene-based curing agents, fluorene-based curing agents can be used alone or in combination of two or more. Examples of the phenol compound include HE-610C and 620C manufactured by Air Water Co., Ltd., TD-2131, TD-2106, TD-2093, TD-2091, TD-2090, VH-4150 manufactured by DIC Corporation, VH-4170, KH-6021, KA-1160, KA-1163, KA-1165, TD-2093-60M, TD-2090-60M, LF-6161, LF-4871, LA-7052, LA-7054, LA- 7751, LA-1356, LA-3018-50P, EXB-9854, SN-170, SN180, SN190, SN475, SN485, SN495, SN375, SN395, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., JX Nippon Oil & Energy Corporation DPP made by Meiwa Kasei Co., Ltd. HF-1M, HF-3M, H -4M, H-4, DL-92, MEH-7500, MEH-7600-4H, MEH-7800, MEH-7785, MEH-7851-4H, MEH-8000H, MEH-8005, manufactured by Mitsui Chemicals, Inc. XL, XLC, RN, RS, RX and the like can be mentioned, but are not limited thereto. These phenol compounds can be used alone or in combination of two or more.

The blending amount of the curing catalyst used in the present invention is sufficient in the proportion usually used. For example, in the case of a phenol compound, 1 to 150 parts by mass, preferably 5 to 5 parts per 100 parts by mass of the thermosetting resin. 100 parts by mass, more preferably 10-50 parts by mass, and in the case of other curing catalysts, 0.01-10 parts by mass, preferably 0.05-5 parts by mass, more preferably 0.1-3 parts by mass. Part.

As the colorant, conventionally known colorants such as red, blue, green and yellow can be used, and any of pigments, dyes and pigments may be used. However, it is preferable not to contain a halogen from the viewpoint of reducing the environmental burden and affecting the human body.

Blue colorant:
Blue colorants include phthalocyanine-based and anthraquinone-based compounds, and pigment-based compounds classified as Pigment, specifically, the following color index (CI; The Society of Dyers and Colorists) (Issued by The Society of Dyers and Colorists) can be listed with numbers: Pigment Blue 15, Pigment Blue 15: 1, Pigment Blue 15: 2, Pigment Blue 15: 3, Pig: Blue 15: 3, Pig Pigment Blue 15: 6, Pigment Blue 16, and Pigment Blue 60.
Solvent Blue 35, Solvent Blue 63, Solvent Blue 68, Solvent Blue 70, Solvent Blue 83, Solvent Blue 87, Solvent Blue 94, Solvent Blue 97, Solvent Blue 97, SolBlu 97, SolBlu 97, SolBlu 97, SolBlu 97 Blue 70 or the like can be used. In addition to the above, a metal-substituted or unsubstituted phthalocyanine compound can also be used.

Green colorant:
Similarly, as the green colorant, there are phthalocyanine series and anthraquinone series. Specifically, Pigment Green 7, Pigment Green 36, Solvent Green 3, Solvent Green 5, Solvent Green 20, Solvent Green 28, and the like can be used. . In addition to the above, a metal-substituted or unsubstituted phthalocyanine compound can also be used.

Yellow colorant:
Examples of yellow colorants include monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, anthraquinone, and the like.
Anthraquinone series: Solvent Yellow 163, Pigment Yellow 24, Pigment Yellow 108, Pigment Yellow 193, Pigment Yellow 147, Pigment Yellow 199, Pigment Yellow 202.
Isoindolinone series: Pigment Yellow 110, Pigment Yellow 109, Pigment Yellow 139, Pigment Yellow 179, Pigment Yellow 185.
Condensed azo type: Pigment Yellow 93, Pigment Yellow 94, Pigment Yellow 95, Pigment Yellow 128, Pigment Yellow 155, Pigment Yellow 166, Pigment Yellow 180.
Benzimidazolone series: Pigment Yellow 120, Pigment Yellow 151, Pigment Yellow 154, Pigment Yellow 156, Pigment Yellow 175, Pigment Yellow 181.
Monoazo type: Pigment Yellow 1, 2, 3, 4, 5, 6, 9, 10, 12, 61, 62, 62: 1, 65, 73, 74, 75, 97, 100, 104, 105, 111, 116 , 167, 168, 169, 182, 183.
Disazo type: Pigment Yellow 12, 13, 14, 16, 17, 55, 63, 81, 83, 87, 126, 127, 152, 170, 172, 174, 176, 188, 198.

Red colorant:
Examples of red colorants include monoazo, diazo, azo lake, benzimidazolone, perylene, diketopyrrolopyrrole, condensed azo, anthraquinone, and quinacridone. It is done.
Monoazo type: Pigment Red 1,2,3,4,5,6,8,9,12,14,15,16,17,21,22,23,31,32,112,114,146,147,151 , 170, 184, 187, 188, 193, 210, 245, 253, 258, 266, 267, 268, 269.
Disazo: Pigment Red 37, 38, 41.
Monoazo lake system: Pigment Red 48: 1, 48: 2, 48: 3, 48: 4, 49: 1, 49: 2, 50: 1, 52: 1, 52: 2, 53: 1, 53: 2, 57 : 1, 58: 4, 63: 1, 63: 2, 64: 1, 68.
Benzimidazolone series: Pigment Red 171, Pigment Red 175, Pigment Red 176, Pigment Red 185, Pigment Red 208.
Perylene: Solvent Red 135, Solvent Red 179, Pigment Red 123, Pigment Red 149, Pigment Red 166, Pigment Red 178, Pigment Red 179, Pigment Red 190, Pigment Red 24, Pigment Red 24,
Diketopyrrolopyrrole series: Pigment Red 254, Pigment Red 255, Pigment Red 264, Pigment Red 270, Pigment Red 272.
Condensed azo: Pigment Red 220, Pigment Red 144, Pigment Red 166, Pigment Red 214, Pigment Red 220, Pigment Red 221, and Pigment Red 242.
Anthraquinone series: Pigment Red 168, Pigment Red 177, Pigment Red 216, Solvent Red 149, Solvent Red 150, Solvent Red 52, Solvent Red 207.
Quinacridone series: Pigment Red 122, Pigment Red 202, Pigment Red 206, Pigment Red 207, Pigment Red 209.

In addition, for the purpose of adjusting the color tone, a colorant such as purple, orange, brown, or black may be added.
Specifically, Pigment Violet 19, 23, 29, 32, 36, 38, 42, Solvent Violet 13, 36, C.I. I. Pigment orange 1, C.I. I. Pigment orange 5, C.I. I. Pigment orange 13, C.I. I. Pigment orange 14, C.I. I. Pigment orange 16, C.I. I. Pigment orange 17, C.I. I. Pigment orange 24, C.I. I. Pigment orange 34, C.I. I. Pigment orange 36, C.I. I. Pigment orange 38, C.I. I. Pigment orange 40, C.I. I. Pigment orange 43, C.I. I. Pigment orange 46, C.I. I. Pigment orange 49, C.I. I. Pigment orange 51, C.I. I. Pigment orange 61, C.I. I. Pigment orange 63, C.I. I. Pigment orange 64, C.I. I. Pigment orange 71, C.I. I. Pigment orange 73, C.I. I. Pigment brown 23, C.I. I. Pigment brown 25, C.I. I. Pigment black 1, C.I. I. Pigment Black 7 etc.

The specific blending ratio of the colorant can be appropriately adjusted depending on the type of colorant used and the type of other additives.

Examples of organic solvents include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, diethylene glycol Glycol ethers such as monoethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, cellosolve acetate, diethylene glycol monoethyl ether acetate and esterified products of the above glycol ethers; Alcohols such as ethanol, propanol, ethylene glycol, propylene glycol; Mention may be made of petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, a petroleum solvent or the like, such as solvent naphtha; down, aliphatic hydrocarbons such as decane.

Further, if necessary, known and commonly used additives such as an antifoaming agent / leveling agent, a thixotropy imparting agent / thickening agent, a coupling agent, a dispersing agent, a flame retardant and the like can be contained.

The curable resin composition of the present invention may be used as a dry film or as a liquid. The curable resin composition of the present invention can also be used as a prepreg that has been coated or impregnated into a sheet-like fibrous base material such as glass cloth, glass and aramid nonwoven fabric, and semi-cured. When used as a liquid, it may be one-component or two-component or more. As a two-component composition, for example, a fine cellulose fiber and an active ester compound may be separated.

The dry film of the present invention has a resin layer obtained by applying and drying the curable resin composition of the present invention on a carrier film. When forming a dry film, first, the curable resin composition of the present invention is diluted with the above organic solvent to adjust to an appropriate viscosity, and then a comma coater, a blade coater, a lip coater, a rod coater, and a squeeze coater. Apply a uniform thickness on the carrier film using a reverse coater, transfer roll coater, gravure coater, spray coater or the like. Thereafter, the applied composition is usually dried at a temperature of 40 to 130 ° C. for 1 to 30 minutes to form a resin layer. The coating film thickness is not particularly limited, but in general, the film thickness after drying is appropriately selected in the range of 3 to 150 μm, preferably 5 to 60 μm.

As the carrier film, a plastic film is used. For example, a polyester film such as polyethylene terephthalate (PET), a polyimide film, a polyamideimide film, a polypropylene film, a polystyrene film, or the like can be used. The thickness of the carrier film is not particularly limited, but is generally appropriately selected within the range of 10 to 150 μm. More preferably, it is in the range of 15 to 130 μm.

After the resin layer made of the curable resin composition of the present invention is formed on the carrier film, a cover that can be peeled off on the surface of the resin layer for the purpose of preventing dust from adhering to the surface of the resin layer. It is preferable to laminate films. As the peelable cover film, for example, a polyethylene film, a polytetrafluoroethylene film, a polypropylene film, a surface-treated paper, or the like can be used. The cover film only needs to have an adhesive force between the resin layer and the resin film that is smaller than that between the resin layer and the carrier film when the cover film is peeled off.

In the present invention, the resin layer may be formed by applying and drying the curable resin composition of the present invention on the cover film, and a carrier film may be laminated on the surface. That is, as the film to which the curable resin composition of the present invention is applied when producing a dry film in the present invention, either a carrier film or a cover film may be used.

The cured product of the present invention is obtained by curing the curable resin composition of the present invention or the resin layer in the dry film of the present invention.

The electronic component of the present invention comprises the cured product of the present invention, and specifically includes a printed wiring board and the like. The cured product of the present invention can be suitably used in electronic components that require insulation reliability between layers. In particular, by using a multilayer printed wiring board using the resin composition of the present invention as an interlayer insulating material, it is possible to have good interlayer insulation reliability.

FIG. 1 is a partial cross-sectional view showing a configuration example of a multilayer printed wiring board according to an example of an electronic component of the present invention. The illustrated multilayer printed wiring board can be manufactured, for example, as follows. First, a through hole is formed in the core substrate 2 on which the conductor pattern 1 is formed. The through hole can be formed by an appropriate means such as a drill, a die punch, or laser light. Then, a roughening process is performed using a roughening agent. Generally, the roughening treatment is carried out by swelling with an organic solvent such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, or methoxypropanol, or an alkaline aqueous solution such as caustic soda or caustic potash. It is carried out using an oxidizing agent such as salt, ozone, hydrogen peroxide / sulfuric acid or nitric acid.

Next, the conductor pattern 3 is formed by a combination of electroless plating or electrolytic plating. The step of forming the conductor layer by electroless plating is a step of immersing in an aqueous solution containing a plating catalyst, adsorbing the catalyst, and then immersing in a plating solution to deposit the plating. A predetermined circuit pattern is formed on the conductor layer on the surface of the core substrate 2 in accordance with a conventional method (subtractive method, semi-additive method, etc.), and a conductor pattern 3 is formed on both sides as shown. At this time, a plated layer is also formed in the through hole, and as a result, the connection portion 4 of the conductor pattern 3 of the multilayer printed wiring board and the connection portion 1a of the conductor pattern 1 are electrically connected. Through hole 5 is formed.

Next, for example, by applying a thermosetting composition by an appropriate method such as a screen printing method, a spray coating method, or a curtain coating method, the interlayer insulating layer 6 is formed by heating and curing. When a dry film or prepreg is used, the interlayer insulating layer 6 is formed by laminating or hot plate pressing and heat curing. Next, vias 7 for electrically connecting the connection portions of the conductor layers are formed by appropriate means such as laser light, and the conductor pattern 8 is formed by the same method as the conductor pattern 3. Further, the interlayer insulating layer 9, the via 10 and the conductor pattern 11 are formed by the same method. Then, a multilayer printed wiring board is manufactured by forming the solder resist layer 12 in the outermost layer. In the above, the example in which the interlayer insulating layer and the conductor layer are formed on the multilayer substrate has been described. However, a single-sided substrate or a double-sided substrate may be used instead of the multilayer substrate.

Hereinafter, the present invention will be described in more detail with reference to examples.
[Preparation of fine cellulose fiber]
Production Example 1 (CNF1)
Bleached kraft pulp fiber of conifers (Machenchie CSF 650 ml, manufactured by Fletcher Challenge Canada) was sufficiently stirred with 9900 g of ion-exchanged water, and then TEMPO (2,2,6,6-tetramethyl manufactured by ALDRICH, Inc.) was added to 100 g of the pulp mass. Piperidine 1-oxyl free radical) 1.25 mass%, sodium bromide 12.5 mass%, and sodium hypochlorite 28.4 mass% were added in this order. Using a pH stud, 0.5 M sodium hydroxide was added dropwise to maintain the pH at 10.5. After carrying out the reaction for 120 minutes (20 ° C.), dropping of sodium hydroxide was stopped to obtain oxidized pulp. The oxidized pulp obtained using ion-exchanged water was sufficiently washed and then dehydrated. Thereafter, 3.9 g of oxidized pulp and 296.1 g of ion-exchanged water were subjected to a refining treatment twice at 245 MPa using a high-pressure homogenizer (manufactured by Sugino Machine, Starburst Lab HJP-2 5005), and carboxyl group-containing fine cellulose fibers A dispersion (solid content concentration 1.3% by mass) was obtained.

Next, 4088.75 g of the obtained carboxyl group-containing fine cellulose fiber dispersion is put into a beaker, and 4085 g of ion-exchanged water is added to form a 0.5 mass% aqueous solution, and then at room temperature (25 ° C.) with a mechanical stirrer for 30 minutes. Stir. Subsequently, 245 g of 1M hydrochloric acid aqueous solution was added and reacted at room temperature for 1 hour. After completion of the reaction, the mixture was reprecipitated with acetone, filtered, and then washed with acetone / ion exchange water to remove hydrochloric acid and salts. Finally, acetone was added and filtered to obtain an acetone-containing acid-type cellulose fiber dispersion (solid content concentration: 5.0% by mass) in which carboxyl group-containing fine cellulose fibers were swollen in acetone. After completion of the reaction, the mixture was filtered, and then washed with ion exchanged water to remove hydrochloric acid and salts. After replacing the solvent with acetone, the solvent was replaced with DMF, and the DMF-containing acid-type cellulose fiber dispersion (average fiber diameter 3.3 nm, solid content concentration 5.0 mass%) in a state where the carboxyl group-containing fine cellulose fibers were swollen. Obtained.

Production Example 2 (CNF2)
40 g of the DMF-containing acid-type cellulose fiber dispersion obtained in Production Example 1 and 0.3 g of hexylamine were placed in a beaker equipped with a magnetic stirrer and a stir bar, and dissolved in 300 g of ethanol. The reaction solution was reacted at room temperature (25 ° C.) for 6 hours. After completion of the reaction, the mixture was filtered, washed with DMF, and solvent-replaced to obtain a fine cellulose fiber composite (solid content concentration 5.0% by mass) in which an amine was connected to fine cellulose fibers via an ionic bond.
CNF produced by the method of Production Example 2 has particularly good dispersibility, and can be dispersed by a general method without using a special disperser such as a high-pressure homogenizer.

Production Example 3 (CNF3)
10% by mass of fine cellulose fibers (BiNFi-s manufactured by Sugino Machine Co., Ltd., average fiber diameter of 80 nm) was subjected to dehydration filtration, 10 times the amount of carbitol acetate as the amount of the filter substance was added, and the mixture was stirred for 30 minutes and then filtered. This substitution operation was repeated three times, and 20 times the amount of the filtered substance was added to carbitol acetate to prepare a fine cellulose fiber dispersion (solid content concentration 5.0 mass%).

[Preparation of cellulose nanocrystal particles]
Production Example 4 (CNC1)
The dried softwood bleached kraft pulp paper was processed with a cutter mill and a pin mill to form cotton-like fibers. 100 g of this cotton-like fiber was taken in absolute dry mass, suspended in 2 L of 64% sulfuric acid aqueous solution, and hydrolyzed at 45 ° C. for 45 minutes.

After the suspension thus obtained was filtered, 10 L of ion exchange water was poured, and the mixture was stirred and dispersed uniformly to obtain a dispersion. Subsequently, the process of filtering and dehydrating the dispersion was repeated three times to obtain a dehydrated sheet. Next, the obtained dehydrated sheet was diluted with 10 L of ion-exchanged water, and a 1N sodium hydroxide aqueous solution was added little by little while stirring to adjust the pH to about 12. Thereafter, the suspension was filtered and dehydrated, 10 L of ion exchange water was added, and the process of stirring and filtering and dehydrating was repeated twice.

Next, ion exchange water was added to the obtained dehydration sheet to prepare a 2% suspension. This suspension was passed 10 times at a pressure of 245 MPa with a wet atomizer (“Ultimizer” manufactured by Sugino Machine Co., Ltd.) to obtain an aqueous dispersion of cellulose nanocrystal particles. *

Thereafter, the solvent was replaced with acetone, and then the solvent was replaced with DMF to obtain a DMF dispersion liquid (solid content concentration 5.0 mass%) in which cellulose nanocrystal particles were swollen. As a result of observing and measuring cellulose nanocrystal particles in the obtained dispersion with AFM, the average crystal width was 10 nm and the average crystal length was 200 nm.

Production Example 5 (CNC2)
Manufactured in the same manner except that the cellulose raw material in Production Example 4 was changed to absorbent cotton (manufactured by White Cross Co., Ltd.) to obtain a DMF dispersion (solid content concentration 5.0 mass%) in which cellulose nanocrystal particles were swollen. It was. As a result of observing and measuring cellulose nanocrystal particles in the obtained dispersion with AFM, the average crystal width was 7 nm and the average crystal length was 150 nm.

According to the description in Tables 1 to 4 below, each component was mixed and stirred, and then dispersed using a high-pressure homogenizer Nanovater NVL-ES008 manufactured by Yoshida Kikai Kogyo, and dispersed 6 times to prepare each composition. The numerical values in Tables 1 to 4 indicate parts by mass.

[Measurement of thermal expansion coefficient]
Each composition was applied to a PET film having a thickness of 38 μm with an applicator having a gap of 120 μm, and dried at 90 ° C. for 10 minutes in a hot-air circulating drying oven to obtain a dry film having a resin layer of each composition. Thereafter, the resin layer of each composition was laminated on a 18 μm thick copper foil with a vacuum laminator at 60 ° C. under a pressure of 0.5 MPa for 60 seconds, and the PET film was peeled off. Then, it heated and hardened at 180 degreeC for 30 minute (s) with the hot-air circulation type drying furnace, the copper foil was peeled off, and the sample of the cured film was obtained. The produced sample for thermal expansion measurement was cut into 3 mm width × 30 mm length. The test piece was elevated at 5 ° C./min from 20 to 250 ° C. in a tensile mode using a TMA (Thermomechanical Analysis) Q400 manufactured by T.A. Then, the temperature was lowered from 250 to 20 ° C. at a rate of 5 ° C./min. The coefficient of thermal expansion (ppm / K) at 25 ° C. and 200 ° C. was determined when the temperature was lowered. The temperature at the point of rapid change in the coefficient of thermal expansion was defined as Tg (glass transition point). The results are shown in Tables 1 to 4.

[Relative permittivity, dissipation factor]
Each composition was applied to a PET film having a thickness of 38 μm with an applicator having a gap of 200 μm, and dried at 90 ° C. for 20 minutes in a hot air circulating drying oven to obtain a dry film having a resin layer of each composition. After that, an electrolytic copper foil with a thickness of 18 μm with a glossy surface facing upward and a tape fixed to a 1.6 mm thick FR-4 copper-clad laminate with a vacuum laminator at 60 ° C. and a pressure of 0.5 MPa. The resin layer of each composition was laminated by pressure bonding for 60 seconds under the conditions, the PET film was peeled off, and cured by heating at 180 ° C. for 30 minutes in a hot air circulating drying oven. And the fixed tape was peeled off, the electrolytic copper foil was peeled off, and it cut out to the magnitude | size of 1.7 mm x 100 mm, and made it the sample for evaluation. The measurement was performed with a network analyzer E-507 manufactured by Keysight Technologies, Inc. using a cavity resonator (5 GHz) manufactured by Kanto Electronics Application Development. In the evaluation of relative permittivity, the average value measured three times was less than 2.8, ◎ was 2.8 or more and less than 3.0, and x was 3.0 or more. The dielectric loss tangent was evaluated as “平均” when the average value measured three times was less than 0.02, and “x” when 0.02 or more. The respective results are shown in Tables 1 to 4.

[Solder heat resistance]
On the FR-4 copper-clad laminate with a size of 150 mm x 95 mm and a thickness of 1.6 mm, a solid pattern was formed on the entire surface of each composition by screen printing with 80 mesh tetron bias plate, and then heated at 80 ° C for 30 minutes in a hot air circulation drying oven. It was dried and then heated and cured at 180 ° C. for 30 minutes to obtain a test piece. A rosin-based flux was applied to the cured product side of the composition of the test piece, flowed to a solder layer at 260 ° C. for 60 seconds, washed with propylene glycol monomethyl ether acetate, and then washed with ethanol. About the test piece, the swelling and peeling of the coating film and the change of the surface state were observed visually. The case where abnormality was observed due to blistering or peeling of the coating film, dissolution or softening of the surface was evaluated as x, and the case where the abnormality was not observed was evaluated as ◯. The evaluation results are shown in Tables 1 to 4.

[Insulation]
Each composition was applied to a PET film having a thickness of 38 μm with an applicator having a gap of 120 μm, and dried at 90 ° C. for 10 minutes in a hot-air circulating drying oven to obtain a dry film having a resin layer of each composition. After that, it is pressure-bonded for 60 seconds on the A coupon of IPC MULTI-PURPOSE TEST BOARD B-25 formed on a 1.6 mm thick FR-4 substrate with a copper thickness of 35 μm using a vacuum laminator at 60 ° C. and a pressure of 0.5 MPa. Then, the resin layer of each composition was laminated, the PET film was peeled off, and cured by heating at 180 ° C. for 30 minutes in a hot air circulating drying oven. Next, the lower end of the IPC MULTI-PURPOSE TEST BOARD B-25 was cut into an electrically independent terminal (cut along the dotted line in FIG. 2). And the bias of DC500V was applied so that the upper part of A coupon might become a cathode and a lower part might become an anode, and the insulation resistance value was measured. In the evaluation, a sample having an insulation resistance value of 100 GΩ or more was evaluated as ◯, and a sample having an insulation resistance value of less than 100 GΩ was evaluated as x. The results are shown in Tables 1 to 4.

* 1) Thermosetting resin 1: Epiclone HP-7200 Cyclohexanone varnish with a solid content of 50% by mass (cyclic ether compound having a dicyclopentadiene skeleton)
* 2) Thermosetting resin 2: manufactured by Epicron N-740 DIC Corporation Cyclohexanone varnish with a solid content of 50% by mass * 3) Thermosetting resin 3: manufactured by Epicron 830 DIC Corporation * 4) Thermosetting resin 4 : JER827 manufactured by Mitsubishi Chemical Corporation * 5) Thermosetting resin 5: Bisphenol A diacetate manufactured by Tokyo Chemical Industry Co., Ltd. (active ester)
* 6) Thermosetting resin 6: Epicron HPC-8000-65T manufactured by DIC Corporation (active ester, solid content 65% by mass)
* 7) Thermosetting resin 7: HF-1 Meiwa Kasei Co., Ltd. Solid content 60 mass% cyclohexanone varnish * 8) Curing catalyst 1: 2E4MZ (2-ethyl-4-methylimidazole) Shikoku Kasei Kogyo Co., Ltd. * 9) Filler 1: Admafine SO-C2 (manufactured by Admatechs Co., Ltd.) (silica) Average particle size 0.4-0.6μm
* 10) Organic solvent 1: Dimethylformamide * 11) Antifoaming agent 1: BYK-352 manufactured by Big Chemie Japan Co., Ltd.

* 12) Filler 2: B-30 Sakai Chemical Industry Co., Ltd. Barium sulfate * 13) Filler 3: DAW-07 Denka Co., Ltd. Alumina * 14) Dispersant 1: DISPERBYK-111, manufactured by BYK Chemie

As is apparent from the results described in Tables 1 to 4, by including fine powders such as fine cellulose fibers and cellulose nanocrystal particles and an active ester compound, not only at room temperature, but also at a high temperature range during component mounting. However, it was confirmed that a curable resin composition capable of maintaining a low coefficient of thermal expansion and having low dielectric properties can be obtained. Moreover, from the evaluation results of solder heat resistance, it was confirmed that each composition of the examples was excellent in heat resistance and chemical resistance and could be used as a wiring board composition.

1, 3, 8, 11 Conductor pattern 2 Core substrate 1a, 4 Connection portion 5 Through hole 6, 9 Interlayer insulating layer 7, 10 Via 12 Solder resist layer

Claims (5)

1. A curable resin composition comprising a fine powder having at least one dimension smaller than 100 nm and an active ester compound.
2. The curable resin composition according to claim 1, further comprising a filler.
3. A dry film comprising a resin layer obtained by applying and drying the curable resin composition according to claim 1 on a film.
4. A cured product, wherein the curable resin composition according to claim 1 or the resin layer of the dry film according to claim 3 is cured.
5. An electronic component comprising the cured product according to claim 4.
   

Images