JPH10316721A - Alkali-soluble resin and image forming material using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] A material for a protective film and an insulating film of an electronic device,
Alkali-soluble resin having fine workability and heat resistance required for image forming materials used for ink resins for LCD color filters, etc., one-pack type image forming materials with excellent storage stability, and image elements with excellent heat resistance SOLUTION: In a copolymer resin comprising a (meth) acrylic acid component (A) and an alicyclic epoxy group-containing polymerizable unsaturated monomer component (B) as essential monomer components, (A) ) Is 20 to 45 mol% of the total monomer components,
An alkali-soluble resin having a copolymerization amount of (B) of 80 to 200% of (A) and a weight average molecular weight of more than 1,000, and a monomer component (C) other than (A) and (B), An alkali-soluble resin obtained by copolymerizing an aliphatic polycyclic compound in an amount of 5 mol% or more of a monomer component, an image-forming material using the alkali-soluble resin, and an image element formed by the image-forming material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an alkali-soluble resin containing an alicyclic epoxy group-containing polymerizable unsaturated monomer and (meth) acrylic acid as essential polymerization components, and a one-pack storage using the same. The present invention relates to an excellent image forming material and an formed image element having excellent heat resistance.

[0002]

2. Description of the Related Art Protective films, insulating films and LCDs for electronic devices
An image forming material used for a color filter or the like is required to have heat resistance in addition to fine workability. For example, if the heat resistance is low, thermal decomposition or softening of the resin occurs during high-temperature processing such as sputtering of a transparent electrode, wire bonding with a circuit, and solder immersion, resulting in dimensional change, cracking, and adhesion of an image element. This causes a problem such as a defect.

Generally, an acrylic acid-containing copolymer resin containing (meth) acrylic acid as a copolymer component is used for image formation using photolithography. However, it is known that in the acrylic acid-containing copolymer resin, the remaining carboxyl group acts as an acid catalyst at a high temperature to promote a dealcohol residue reaction of the acrylate compound, thereby causing thermal decomposition of the copolymer resin ( Minoru Imoto, Adhesion, 1974.2,
p2). Therefore, when the acrylic resin-containing copolymer resin is used, the film thickness of the image element is reduced, the surface is roughened, and the adhesion is poor after the heat treatment.

Therefore, it is considered that a carboxyl group exists in the resin during alkali development, but it is preferable that the carboxyl group does not exist in the image element after alkali development. For example, Japanese Patent Application Laid-Open No. A quaternary copolymer acrylate resin of a carboxyl group-containing compound, an epoxy group-containing compound, a monoolefin and a diolefin is disclosed as a heat-resistant alkali-developable photosensitive resin that can be finely processed. However, since this copolymer resin uses linear aliphatic glycidyl methacrylate as the epoxy group-containing compound and the epoxy group content ratio to the carboxyl group is not appropriate, some improvement in heat resistance is recognized, but further improvement is observed. The heat resistance improvement requirement cannot be satisfied.

[0005] Crosslinking and curing of a resin by the reaction between an epoxy group and a carboxyl group are widely used as means for curing a coating film. Examples of such a type include a mixed type of an epoxy group-containing resin and a carboxyl group-containing resin, and a self-crosslinkable type having both functional groups in the same molecule. For example, Japanese Patent Application Laid-Open No. 63-135465 discloses a self-adhesive polymer obtained by copolymerizing a monomer component containing a glycidyl group-containing polymerizable unsaturated monomer and a carboxyl group-containing polymerizable unsaturated monomer as main components. Cross-linked resins are disclosed. However, in this method, a glycidyl group and a carboxyl group react during polymerization to form a high molecular weight substance, or a solution of the copolymer resin is gelled, and it is difficult to store the copolymer resin for a long time.

[0006]

Accordingly, an object of the present invention is to provide a protective film material for an electronic device, an insulating film material,
An object of the present invention is to provide an alkali-soluble resin having fine workability and heat resistance required for an image forming material used for an ink resin or the like of a CD color filter. Another object of the present invention is to provide a one-part image forming material having excellent storage stability and an image element having excellent heat resistance.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that a polymerizable unsaturated monomer containing an alicyclic epoxy group and (meth) acrylic acid can be used. The inventors have found that the above-mentioned problems can be solved by optimizing the molar ratio between the epoxy group and the carboxyl group by using an alkali-soluble resin as an essential polymerization component, and completed the present invention based on this finding.

That is, the present invention relates to a copolymer resin formed from a (meth) acrylic acid component (A) and an alicyclic epoxy group-containing polymerizable unsaturated monomer component (B) as essential monomer components. Wherein (A) is 20 to 45 mol% of the total monomer components, (B) is 80 to 200 mol% of (A), and the weight average molecular weight is 1,000 or more. It is a soluble resin, and as a monomer component (C) other than (A) and (B), 5% of all monomer components
It is an alkali-soluble resin obtained by copolymerizing at least mol% of an aliphatic polycyclic compound.

The present invention also relates to an image forming material using the alkali-soluble resin and an image element formed from the image forming material.

Hereinafter, the present invention will be described in detail. The alkali-soluble resin of the present invention contains a (meth) acrylic acid component (A) and an alicyclic epoxy group-containing polymerizable unsaturated monomer component (B) as essential monomer components.
The (meth) acrylic acid serving as the component (A) may be acrylic acid alone or methacrylic acid alone, or both may be used in combination.

The alicyclic epoxy group-containing polymerizable unsaturated monomer serving as the component (B) is a monomer having both a radically polymerizable unsaturated group and an alicyclic epoxy group in one molecule. .
Examples of the radical polymerizable unsaturated group include those represented by the following general formulas (a) to (g), and preferably those represented by the general formula (a).

Embedded image (Wherein, R ₁ represents a hydrogen atom or a methyl group)

The alicyclic epoxy group-containing polymerizable unsaturated monomer having an unsaturated group represented by the general formula (a) includes, for example, compounds represented by the following general formulas (1) to (12). Is mentioned.

Embedded image (Wherein, R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a divalent hydrocarbon group having 1 to 8 carbon atoms, and R ₃ represents a carbon atom having 1 carbon atom.
-20, a divalent hydrocarbon group represented by R ₁ , R ₂ and R ₃
May be the same or different, and w represents a number from 0 to 10)

Specific examples of such an alicyclic epoxy group-containing polymerizable unsaturated monomer include the following compounds.

Embedded image

Examples of the alicyclic epoxy group-containing polymerizable unsaturated monomer other than the radical polymerizable unsaturated group represented by the general formula (a) include the following general formulas (13) to (3)
And the like.

Embedded image

Embedded image (Wherein R ₁ , R ₂ , R ₃ and w are the same as above)

Specific examples of the alicyclic epoxy group-containing polymerizable unsaturated monomer include the following compounds.

Embedded image

Embedded image

Since the alicyclic epoxy group-containing polymerizable unsaturated monomer has an aliphatic cyclic hydrocarbon epoxy group, the crosslinked chain formed by the reaction with a carboxylic acid has a bulky aliphatic cyclic structure (aliphatic). A ring skeleton) to suppress the thermal motion of the crosslinked chain and improve heat resistance. However, if a long-chain structure typified by a long-chain hydrocarbon or the like enters between the radically polymerizable unsaturated group and the alicyclic skeleton, the effect is reduced.
Therefore, the distance between the radically polymerizable unsaturated group and the alicyclic skeleton is preferably short. The length of the radically polymerizable unsaturated group and the length of the alicyclic skeleton depends on the type of the alicyclic skeleton and the type of the above-mentioned radically polymerizable unsaturated group. In the case of the compound represented by the formula, the number of linearly linked elements between the radically polymerizable unsaturated group and the alicyclic skeleton is preferably 5 or less, more preferably 3 or less.

Also, the alicyclic epoxy group-containing polymerizable unsaturated monomer has a feature that it does not gel when a copolymer resin with (meth) acrylic acid is synthesized in a solvent (Daicel Chemical Industries, Ltd. See CYCLOMER Technical Catalog). further,
The image forming material containing the alkali-soluble resin of the present invention,
No gelation during storage and no significant increase in solution viscosity.

The molar ratio of the (meth) acrylic acid component (A) forming the alkali-soluble resin of the present invention must be 20 to 45 mol% of all monomer components. (A)
If the molar ratio is less than 20 mol%, the alkali solubility of the resin is insufficient, and if it exceeds 45 mol%, the alkali solubility becomes too large, and the exposed portion is eroded by alkali during alkali development. The alkali-soluble resin having fine workability required for electronic materials has a molar ratio of (A) of preferably 25 to 40 mol%, more preferably 30 to 40 mol%.
It is.

The molar ratio of the alicyclic epoxy group-containing polymerizable unsaturated monomer component (B) must be 80 to 200 mol% based on the (meth) acrylic acid component (A). . If (B) is less than 80 mol%, a large amount of epoxy groups and unreacted carboxyl groups remain, and the heat decomposition resistance of the resin decreases. If it exceeds 200 mol%, the amount of (meth) acrylic acid that gives alkali solubility is increased. Is restricted. (B)
Is preferably 90 to 180 mol%, more preferably 100 to 150 mol%, based on (A).

The (meth) acrylic acid and the alicyclic epoxy group-containing polymerizable unsaturated monomer form a copolymer resin by radical copolymerization. This copolymer resin is alkali-soluble, and upon contact with an alkali, a carboxyl group in the component (A) and an epoxy group in the component (B) react to form a cross-linking bond. As described above, by copolymerizing (A) and (B), it is possible to suppress weight loss due to a dealcohol residue reaction occurring during heat treatment of a cured product when an image element is formed.

The molecular weight of the alkali-soluble resin of the present invention is 100 in terms of polystyrene equivalent weight average molecular weight (Mw) determined by gel permeation chromatography (GPC).
Must be 0 or more. This molecular weight is 1000
If the particle size is smaller than that, when an image element is formed by photolithography described later, an exposed portion (a portion cured by exposure) is eroded by an alkaline solution during alkali development, and a good fine pattern cannot be obtained. The upper limit of the molecular weight of the alkali-soluble resin is not particularly limited as long as it has sufficient alkali solubility, but is preferably 100,000 or less,
It is more preferably at most 70,000, further preferably at most 50,000. The molecular weight of the alkali-soluble resin is preferably 3,000 or more in order to improve the alkali erosion resistance of the exposed portion during alkali development. The alkali-soluble resin of the present invention may be used by mixing copolymer resins having different weight average molecular weights.

The alkali-soluble resin of the present invention includes (A)
As the monomer component other than (B) and (B), a monomer component copolymerizable with the above-mentioned essential monomer component may be copolymerized. Preferably, the aliphatic polycyclic compound component (C) is (meth)
By adding and copolymerizing the acrylic acid component (A) and the alicyclic epoxy group-containing polymerizable unsaturated monomer component (B), it is possible to increase the Tg of the obtained three-component copolymer resin. . Such an aliphatic polycyclic compound component (C)
The aliphatic polycyclic compound giving (1) may be any compound having a radically polymerizable unsaturated group and an aliphatic polycyclic structure, and examples thereof include a compound represented by the following general formula (34).

Embedded image (Wherein, R ₄ is a hydrogen atom or a methyl group, X is a divalent group,
A represents a group derived from an aliphatic polycyclic hydrocarbon (aliphatic polycyclic skeleton), Y represents a substituent, and n represents the number of substituents.

In the general formula (34), X is, for example, -C
_{OO -, - COO (CH 2} ) n -, - (CH 2) n - is a divalent group such as a, preferably -COO- a. A is a group derived from an aliphatic polycyclic hydrocarbon, specifically, isobornyl groups, tricyclodecanyl groups, dicyclopentenyl groups, dicyclopentenyloxyethyl groups,
Compounds having an aliphatic cyclic skeleton having two or more rings, such as norbornane epoxy groups, norbornane epoxymethyl groups, norbornyl groups, and adamantyl groups are exemplified.
By copolymerizing these compounds, it becomes possible to obtain a three-component copolymer resin having excellent transparency and high heat resistance. On the other hand, a compound having a monocyclic alicyclic skeleton such as a cyclohexyl group has insufficient improvement in heat resistance. Y is a substituent such as a halogen atom, an alkyl group, an alkoxy group, a carboxyl group, an amino group, a hydroxyl group, and the like, and n is the number of the substituents, preferably 0 to 5.

In order to improve the Tg and the thermal decomposition resistance of the alkali-soluble resin of the present invention, it is preferable to copolymerize the aliphatic polycyclic compound component (C) in an amount of 5 mol% or more of all monomer components. If the content of the aliphatic polycyclic compound component (C) is less than 5 mol%, no improvement in Tg and thermal decomposition resistance is observed. The upper limit of this is not particularly limited as long as the amount of the introduced essential monomer component satisfies the conditions of the present invention, and is preferably at least 10 mol%, more preferably at least 20 mol%.

Further, a monomer component (D) for improving compatibility may be copolymerized with the alkali-soluble resin of the present invention. The alkali-soluble resin as an image forming material is required to be compatible with other constituent materials, photopolymerizable monomers, photoreaction initiators, diluents, additives and the like. Here, compatibility means that the substances are mixed well,
This refers to providing a transparent and homogeneous mixture without precipitates and precipitates. If the compatibility is low, not only a uniform image forming material cannot be obtained, but also precipitates and the like sometimes occur in a process of manufacturing a coating film to be used for an electronic material, and as a result, a uniform coating film cannot be obtained. The monomer component (D) capable of introducing such a structure for improving compatibility into an alkali-soluble resin has, for example, a hydroxyl group, an ether structure, an amino structure, an amide structure, a urethane structure, a phosphoric acid structure and the like. Specific examples thereof include copolymerizable compounds, specifically, hydroxyalkyl (meth) acrylates, ethylene glycol (meth) acrylates, aminoalkyl (meth) acrylates, tetrahydrofurfuryl (meth) acrylates, and alkoxyalkyl (meth) acrylates. Examples include acrylates, alkylaminoalkyl (meth) acrylates, glycidyl (meth) acrylate, morpholine (meth) acrylate, phosphoric acid acrylates, N-vinylcaprolactam, and N-vinylpyrrolidone. The copolymerization amount (mol%) of the monomer component (D) is not particularly limited as long as the copolymerization amount of the essential monomer component satisfies the conditions of the present invention. However, from the viewpoint of maintaining heat resistance, the content is preferably 20 mol% or less.

The alkali-soluble resin of the present invention may comprise one or more (meth) acrylic acid components (A) and an alicyclic epoxy group-containing polymerizable unsaturated monomer, if copolymerizable. Component (B), monomer component (C) and monomer component (D) can be included. The monomers to be the alicyclic epoxy group-containing polymerizable unsaturated monomer component (B) and the aliphatic polycyclic compound component (C) may be commercially available products or synthetic products. Although these synthetic methods are not particularly limited,
For example, it can be obtained by an esterification reaction between an alcohol having an alicyclic epoxy group skeleton or an alcohol having an aliphatic cyclic structure and (meth) acrylic acid.

In order to obtain a random copolymer resin having a uniform composition, it is preferable that the monomer reactivity ratio of each of the above radically reactive monomers is close to 1. Therefore, (B),
It is preferable that the monomers used as the components (C) and (D) are (meth) acrylic esters having close reactivity with the (meth) acrylic acid component (A). However, as long as a random copolymer resin can be obtained, it is not limited to (meth) acrylate.

The alkali-soluble resin of the present invention can be produced by a conventionally known polymerization method. For example, the alkali-soluble resin of the present invention can be obtained by radical solution polymerization using benzoyl peroxide (BPO) or azobisisobutylnitrile (AIBN) as a polymerization initiator. At this time, a chain transfer agent or the like may be used for controlling the molecular weight. It is important that the temperature of the polymerization reaction is such that the reaction solution does not gel or an abnormal high molecular weight is formed.
Although it depends on the type and amount of the monomer component, it is preferably 80 ° C.
The temperature is more preferably 75 ° C or less.

In the present invention, the image forming material refers to a material capable of forming an image element by a photolithography method using a resin composition containing the alkali-soluble resin of the present invention. Examples of the image forming material include a composition I comprising an alkali-soluble resin and a diluent (solvent), and a composition II comprising an alkali-soluble resin, a diluent (solvent), a photopolymerizable monomer and a photopolymerization initiator. But are not limited to these. The composition I can form an image element having a fine shape by using a photoresist in combination with alkali development. Since the composition II itself has photocurability, it can be irradiated with light through a photomask in which a fine pattern has been processed and then developed with an alkaline solution to obtain a desired fine image element.

In the image-forming material of the present invention, only one kind of the alkali-soluble resin of the present invention may be used, or two or more kinds of alkali-soluble resins having different chemical structures, compositions and sequences may be used in combination. Good.

The photopolymerizable monomer to be added to the composition II is not particularly limited as long as it has the transparency, heat resistance, strength, hardness and the like required by the obtained cured product. For example, polyfunctional acrylate monomers such as pentaerythritol tetraacrylate and dipentaerythritol hexaacrylate can be used. Also, polyfunctional epoxy compounds which are cured by an acid catalyst, for example, novolak type epoxy resin (Nippon Kayaku Co., Ltd.)
EOCN-102S, EOCN-103S), tetraglycidyldiaminodiphenylmethane (Araldite MY720, manufactured by Nippon Ciba Geigy Co., Ltd.) and the like can be used. From the viewpoint of the sensitivity of the image forming material, the content of the trifunctional or higher functional photopolymerizable monomer is preferably 50% by weight or more based on the total amount of the photopolymerizable monomer.

The photoreaction initiator and the diluent are compatible with the alkali-soluble resin of the present invention, and do not generate precipitates when used as an image forming material, and do not generate precipitates and the like during film formation. As a result, there is no particular limitation as long as there is no problem in using it as an image forming material capable of fine processing. For example, as a photoreaction initiator, a radical generator (Irgacure 907 manufactured by Nippon Ciba Geigy Co., Ltd.),
(TAZ-110 manufactured by Midori Kagaku Co., Ltd.), acid generators (SO-150, SO-170 manufactured by Asahi Denka Co., Ltd.), ferrocene-based photoinitiators (Irgacure 261 manufactured by Nippon Ciba Geigy Co., Ltd.), ( Nippon Soda Co., Ltd. CI-2624,
CI-2639) and the like. As a diluent,
Dioxane, diethylene glycol dimethyl ether,
Solvents such as propylene glycol monomethyl ether-2-acetate, and (meth) acrylate compounds such as isobornyl methacrylate, which are reactive diluents, are also included.

Regarding the photopolymerizable monomer and the photoreaction initiator, a book (for example, Kiyomi Kato, UV curing system,
Sogo Gijutsu Center, published on February 28, 1989, edited by Masaki Shinbo, Epoxy Resin Handbook, Nikkan Kogyo Shimbun,
For example, published on December 25, 1987), from which compounds satisfying the above conditions can be selected as appropriate.

The composition of the image-forming material of the present invention is based on the alkali-soluble resin and diluent (solvent) used, the type of photopolymerizable monomer, the type of photopolymerization initiator, and the physical properties required for the image-forming material such as a solution. Although it differs depending on the viscosity and the like, it generally conforms to a known composition. A typical composition range is as follows: 100 parts by weight of the alkali-soluble resin is mixed with a diluent (solvent) of 150 parts by weight.
To 1200 parts by weight, 20 to 200 parts by weight of a photopolymerizable monomer, and 0.5 to 20 parts by weight of a photopolymerization initiator. further,
With respect to the additives added for the purpose of improving the properties, for example, a leveling agent (3M Florate FC-430 or the like) may be added in an amount of about 0.5 to 5 parts by weight based on 100 parts by weight of the alkali-soluble resin.

The image forming material of the present invention may contain necessary materials and additives depending on the intended use. For example, a color ink or black matrix for LCD, which is one of the image forming materials, is obtained by mixing a pigment with the above composition. If necessary, various additives can be blended for the purpose of improving the properties. Such additives include, for example, sensitizers, surfactants,
Any resin, reactive monomer, and the like can be used.

In the present invention, the term "image element" refers to an element prepared using the above-mentioned image forming material. For example, there are a protective film and an insulating film of an electronic device, a color pixel of an LCD color filter, a black matrix, and the like.

[0037]

The present invention will be specifically described below with reference to examples and comparative examples. The evaluation of the alkali-soluble resin and the image-forming material using the same in Examples and Comparative Examples is as follows unless otherwise specified.

<Acid value> The obtained resin was dissolved in a mixed solution of equal volumes of toluene and ethanol, and the resin was titrated and measured with a 1/10 normal KOH ethanol (50%) aqueous solution using phenolphthalein as an indicator.

<Molecular weight> The molecular weight was determined by gel permeation chromatography (GPC) equipped with an RI (refractive index) detector using tetrahydrofuran as a developing solvent. All molecular weights shown are weight average molecular weights (M
w).

<Molar ratio (mol%) of monomer component in copolymer resin> Determined from the area ratio by NMR measurement.

<Developing Characteristics> The image forming material was spin-coated on a glass substrate coated with SiO ₂ under the conditions that the film thickness after post-baking was 1.5 to 2.0 μm, and immediately maintained at 80 ° C. Pre-baked on a hot plate for 3 minutes to form a tack-free coating. Pigment-free transparent image-forming material This coating film is passed through a mask engraved with a fine pattern.
Exposure was performed at 0 mJ / cm ² , development was performed at 23 ° C. for a predetermined time using a 0.7 wt% aqueous solution of diethanolamine (DEA), and post-baking was performed at 200 ° C. for 1 hour. The negative pattern was observed, and the developing characteristics were judged based on the following criteria. Material for image formation for LCD ink This coating film is passed through a mask engraved with a fine pattern.
Exposure was performed at 0 mJ / cm ² , development was performed at 25 ° C. for a predetermined time using a 0.01% by weight KOH aqueous solution, and post-baking was performed at 200 ° C. for 30 minutes. The negative pattern was observed, and the developing characteristics were judged based on the following criteria. 20 μm pattern is not cut well ○ 20 μm pattern is not cut well ×

<Adhesion> A coating film was formed according to the method described in Evaluation of development characteristics except that the entire surface was exposed. A cross cut was made on the coating film so as to form at least 100 cross-cuts, and then a peeling test was performed using cellophane tape, and the state of the cross-cut was visually evaluated. The ranking of the evaluation is as follows. No peeling observed ○ Some peeling observed ×

<Surface Hardness>
A pencil hardness test was performed according to the S standard. The pencil hardness at which no scratch was observed on the surface was defined as the surface hardness.

<Chemical resistance>
N-methyl-2-pyrrolidone (NMP) at 4 DEG C. and 4% K
After immersion in an OH aqueous solution for 10 minutes, an adhesion test was performed. The judgment was based on the adhesion test.

<Transparency> The visible light absorption spectrum of a coating film having a thickness of 2 μm after the post-baking using the image forming material was measured, and the result was shown by the light transmittance (%) at a wavelength of 400 nm.

<Heat Resistance (Transparency)> A coating film having a thickness of 2 μm after post-baking using an image forming material was applied at 230 ° C. for 1 hour.
After the heat treatment at 230 ° C. for 3 hours, the above-mentioned adhesion test and transparency test were performed.

<Hue> Each value of the Yxy color system was determined for a coating film having a thickness of 1.5 μm after post-baking using a color ink.

<Heat resistance (hue)> A 1.5 μm-thick coated film after post-baking using a color ink was heat-treated at 230 ° C. for 1 hour and 230 ° C. for 3 hours. The color difference dE of the * b * color system was determined.

<Residual film ratio> A coating film was formed according to the method described in Evaluation of development characteristics except that the entire surface was exposed. After measuring the film thickness of the coating film, 230 ° C
After the heat treatment for a long time, the film thickness was measured, and the residual film ratio was calculated by the following equation. Remaining film ratio (%) = film thickness after heat treatment at 230 ° C./film thickness after post-bake × 100

<Weight loss ratio> The cured product of the obtained copolymer resin and image-forming material was heated from room temperature to 20% using a thermobalance.
The temperature was raised to 0 ° C. at a rate of 10 ° C./min, and the temperature was held at 200 ° C. for 1 hour. Then, the temperature was raised to 230 ° C., and the weight was measured after 1 hour and 3 hours at 230 ° C. The weight loss rate was calculated by the following equation. Weight loss rate (%) = (Wt ₀ −Wt) / Wt ₀
× 100 Wt ₀ : Weight immediately after rising to 230 ° C. Wt: Weight after 1 hour or 3 hours at 230 ° C.

<Evaluation of Heat-Resistant Weight Reduction> Based on the following criteria, the heat-resistant weight loss was evaluated from the weight reduction rate of the copolymer resin. Weight loss rate at 230 ° C. for 1 hour: less than 1.5% ○ ,:
1.5% or more × Weight loss rate at 230 ° C. for 3 hours: less than 3.0% ○ ,:
3.0% or more ×

<Epoxy group / carboxyl group molar ratio (Ep
/ Cb molar ratio)> Ratio of alicyclic epoxy group (mol%) and carboxyl group (mol%) in copolymer resin

<Storage Stability> After the prepared image forming material was stored at room temperature for one month, the solution viscosity was measured and judged according to the following criteria. When the increase in viscosity after one month is 50% or less of that at the time of preparation ○ When the increase in viscosity after one month is more than 50% at the time of preparation or when gelation occurs ×

Example 1 300 ml equipped with a 100 ml dropping funnel, a cooling pipe and a stirrer
After flowing an appropriate amount of nitrogen gas into the ml four-necked flask to sufficiently dry the system, the flow rate of nitrogen gas was set at about 50 ml / min. Epoxycyclohexylmethyl methacrylate (M-100 manufactured by Daicel Chemical Industries, Ltd .; abbreviation: M-10)
0) 17.9 g (0.0890 mol), 9.58 g of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd., abbreviation: MAA)
(0.111 mol), isobornyl methacrylate (Light ester IB-X, manufactured by Kyoeisha Chemical Co., Ltd., abbreviation: IB
-X) A solution prepared by dissolving 30 g (0.135 mol) of 3.32 g of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, abbreviation: AIBN) in 30 g of 1,4-dioxane was added to a dropping funnel. 50 g of dioxane was placed in a four-necked flask. After immersing the flask in an oil bath set at 80 ° C., the reaction solution was dropped from the dropping funnel over about 2 hours. After the completion of the dropwise addition, the reaction was carried out for about 1.5 hours in an oil bath set at 80 ° C. After cooling the reaction solution to near room temperature, 30 g of 1,4-dioxane was added to lower the viscosity of the reaction solution, and it was gradually dropped into about 800 g of n-hexane to obtain a white solid. After sufficiently washing the obtained white solid, it was air-dried and vacuum-dried to obtain a target acrylate copolymer resin. The polymerization reaction proceeded quantitatively, and an acrylate copolymer resin A-1 having a composition ratio almost equal to the charged amount was obtained. The copolymer resin A-1 had an epoxy group / carboxyl group molar ratio of 0.82 and an aliphatic polycyclic skeleton (isobornyl methacrylate skeleton) of 40 mol%. Table 1 shows the charged amount, the yield of the copolymer resin A-1, the molecular weight, the epoxy group / carboxyl group molar ratio (Ep / Cb molar ratio), and the acid value. Next, the decrease in heat resistant weight of the copolymer resin A-1 was examined by the above-described method for evaluating heat resistant weight decrease. Table 1 shows the results.
From Table 1, it is recognized that the copolymer resin A-1 has excellent heat resistance weight reduction.

Examples 2 to 7 In the same experiment as in Example 1, acrylate copolymer resins A-2 to A-7 were prepared by changing the charged amounts. The polymerization reaction proceeded quantitatively, and acrylate copolymer resins A-2 to A-7 having a composition ratio almost equal to the charged amount were obtained. Table 1 shows the charged amounts, the yields of the copolymer resins A-2 to A-7, the molecular weight, the epoxy group / carboxyl group molar ratio (Ep / Cb molar ratio), and the acid value. The copolymer resins A-2 to A-7 had an epoxy group / carboxyl group molar ratio of 1.00 to 2.00 and had an aliphatic polycyclic skeleton (isobornyl methacrylate skeleton). The copolymer resin having an epoxy group / carboxyl group molar ratio of 1.00 has an acid value of 96.9 as an index of alkali solubility.
143. Table 1 shows the results of examining the heat-resistant weight loss of the copolymer resins A-2 to A-7 by the above-described method of evaluating heat-resistant weight loss.
Shown in From Table 1, the copolymer resins A-2 to A-7 have excellent heat resistance weight reduction. In addition, even if the acid value serving as an index of alkali solubility is changed, it is recognized that the copolymer resin has excellent heat resistance weight reduction as long as the epoxy group / carboxyl group molar ratio is within the range specified in the present invention. .

Examples 8 to 9 In the same experiment as in Example 1, acrylate copolymer resins B-1 and B-2 were prepared in which the charged amount of isobornyl methacrylate (IB-X) was 0. The polymerization reaction proceeded quantitatively, and acrylate copolymer resins B-1 and B-2 having a composition ratio almost equal to the charged amount were obtained. Charge amount,
Table 1 shows the yield, molecular weight, epoxy group / carboxyl group molar ratio (Ep / Cb molar ratio) and acid value of copolymer resins B-1 and B-2.
Shown in The copolymer resins B-1 and B-2 have an epoxy group / carboxyl group molar ratio of 1.00 and 1.86, respectively, and do not have an aliphatic polycyclic skeleton. Copolymer resin B-
Table 1 shows the results obtained by examining the decrease in heat-resistant weight of Sample No. 1 and B-2 by the above-described method of evaluating the decrease in heat-resistant weight. From Table 1, it is recognized that the copolymer resins B-1 and B-2 have excellent heat resistance weight reduction.

Comparative Examples 1 to 4 In the same experiment as in Example 1, acrylate copolymer resins R-1 to R-4 were prepared by changing the charged amount. The polymerization reaction proceeded quantitatively, and acrylate copolymer resins R-1 to R-4 having a composition ratio almost equal to the charged amount were obtained. Table 2 shows the charged amount, the yield of the acrylate copolymer resins R-1 to R-4, the molecular weight, the epoxy group / carboxyl group molar ratio (Ep / Cb molar ratio), and the acid value. The copolymer resins R-1 to R-4 have an epoxy group /
The carboxyl group molar ratio is 0.50, 0.6 respectively.
7, 0.76 and 3.00, which are out of the range defined by the present invention. Table 2 shows the results of examining the heat-resistant weight loss of the copolymer resins R-1 to R-4 by the above-described method of evaluating heat-resistant weight loss. From Table 2, it is recognized that the copolymer resins of R-1 to R-4 are inferior to the copolymer resin of the present invention in heat resistance weight loss.

Comparative Example 5 In the same experiment as in Example 1, glycidyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd .; abbreviation: G) was used instead of epoxycyclohexylmethyl methacrylate (M-100).
MA) was used to prepare an acrylate copolymer resin R-5. The polymerization reaction proceeded quantitatively, and an acrylate copolymer resin R-5 having a composition ratio almost equal to the charged amount was obtained. Table 2 shows the charged amount, the yield of the copolymer resin R-5, the molecular weight, the epoxy group / carboxyl group molar ratio (Ep / Cb molar ratio), and the acid value.
Shown in The copolymer resin R-5 has an epoxy group / carboxyl group molar ratio of 1.00, and has an aliphatic linear epoxy in place of the alicyclic epoxy. Table 2 shows the results obtained by examining the decrease in heat-resistant weight of the copolymer resin by the above-described method of evaluating the decrease in heat-resistant weight. Table 2 shows that the copolymer resin R-5 was inferior in the heat resistance weight loss to the copolymer resin having an alicyclic epoxy of the present invention.

Comparative Example 6 In an experiment similar to that in Example 1, an acrylate copolymer resin was prepared by using hydroxyethyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd., abbreviation: HEMA) instead of epoxycyclohexylmethyl methacrylate (M-100). R-6
Was prepared. The polymerization reaction proceeded quantitatively, and an acrylate copolymer resin R-6 having a composition ratio substantially equal to the charged amount was obtained. Table 2 shows the charge amount, the yield of the copolymer resin R-6, the molecular weight, and the acid value. The copolymer resin R-6 has no epoxy group.

[0060]

[Table 1]

[0061]

[Table 2]

Example 10 After dissolving 2 g of the acrylate copolymer resin A-2 of Example 2 in 12 g of ethyl cellosolve, KAYARAD DPH was used.
A (manufactured by Nippon Kayaku Co., Ltd.) 1 g, KAYARPADET-
30 (manufactured by Nippon Kayaku Co., Ltd.), 1 g of silane coupling agent (trade name: SILAACE S-510, manufactured by Chisso Corporation)
0.04 g, Celloxide 2021P (manufactured by Daicel Chemical Industries, Ltd.) 0.278 g, Irgacure 907 (manufactured by Ciba Specialty Chemicals) 0.06 g
Was added and sufficiently stirred and dissolved to prepare an alkali developing type image forming material. The alkali developable image forming material was evaluated for alkali developability, adhesion, surface hardness, chemical resistance, transparency, heat resistance (transparency), residual film ratio, and weight loss rate according to the test methods described above. Table 3 shows the results. From Table 3, it is recognized that the coating film obtained from the image forming material of the present invention satisfies the characteristics required for the image forming material, and further has excellent residual film ratio and weight reduction ratio.

Examples 11 to 12 Instead of the acrylate copolymer resin A-2, the acrylate copolymer resins A-3 and A-7 of Examples 3 and 7 were used.
Was used to prepare an image forming material having the composition shown in Table 3 in the same manner as in Example 10. Table 3 shows the results of evaluating the alkali developability, adhesion, surface hardness, chemical resistance, transparency, heat resistance (transparency), residual film ratio, and weight loss of these in accordance with the test methods described above. From Table 3, it is recognized that the coating film obtained from the image forming material of the present invention satisfies the characteristics required for the image forming material, and further has excellent residual film ratio and weight reduction ratio.

Comparative Example 7 An image forming material having the composition shown in Table 3 was prepared in the same manner as in Example 10 except that the acrylate copolymer resin R-1 of Comparative Example 1 was used instead of the acrylate copolymer resin A-2. Prepared. For this, according to the test method described above, storage stability,
Table 3 shows the results of evaluation of alkali developability, adhesion, surface hardness, chemical resistance, transparency, heat resistance (transparency), residual film ratio, and weight loss ratio. Copolymer resin R-1 having an epoxy group / carboxyl group molar ratio of 0.5 out of the range specified in the present invention.
The coating film obtained from the image forming material using the
It is recognized that the weight loss rate is inferior.

Comparative Example 8 The acrylate copolymer resin R-6 of Comparative Example 6 was used in place of the acrylate copolymer resin A-2, and an image forming material having the composition shown in Table 3 was prepared in the same manner as in Example 10. Prepared. R-6 does not have an alicyclic epoxy group, but the image forming material contains an equivalent amount of a compound having an alicyclic epoxy group (celloxide 2021P). Table 3 shows the results of evaluating the storage stability, alkali developability, adhesion, surface hardness, chemical resistance, transparency, heat resistance (transparency), residual film ratio, and weight loss rate according to the test methods described above. Shown in It is recognized that a coating film obtained from an image forming material containing an equivalent amount of a compound having an alicyclic epoxy group instead of copolymerization is inferior in the residual film ratio and the weight loss ratio.

Comparative Example 9 The acrylate copolymer resin R-5 of Comparative Example 5 was used in place of the acrylate copolymer resin A-2, and an image forming material having the composition shown in Table 3 was prepared in the same manner as in Example 10. Prepared. For this, according to the test method described above, storage stability,
Table 3 shows the results of evaluation of alkali developability, adhesion, surface hardness, chemical resistance, transparency, heat resistance (transparency), residual film ratio, and weight loss ratio. It is recognized that an image forming material using an alkali-soluble resin using a glycidyl group is inferior in storage stability, and further inferior in a remaining film ratio and a weight reduction ratio.

[0067]

[Table 3]

Example 13 Using the acrylate copolymer resin A-4 of Example 4, an ink for LCD having the composition shown in Table 4 was prepared. The reagents described in Table 4 are as follows. Diglyme: diethylene glycol dimethyl ether DPHA: KAYARAD DPHA (Nippon Kayaku Co., Ltd.)
PET-30: KAYARAD PET-30 (manufactured by Nippon Kayaku Co., Ltd.) Saila Ace S-510: silane coupling agent (manufactured by Chisso Corporation) Celloxide 2021P (manufactured by Daicel Chemical) Irgacure 907 (Nihon Ciba Geigy Co., Ltd.) )) TAZ-110 (manufactured by Midori Kagaku Co., Ltd.) Fluorate FC-430 (manufactured by 3M) Pigment dispersion: Blue pigment dispersion (Blue E manufactured by Mikuni Dyestuffs)
X1756-20) (parts by weight of the pigment dispersion in Table 4 are converted to solid content) The thickness of the obtained color ink after post-baking is 1.5.
After spin-coating on a SiO ₂ -coated glass substrate under the condition of μm, it was immediately pre-baked on a hot plate maintained at 80 ° C. for 3 minutes to obtain a tack-free coating film. With respect to this coating film, the results of evaluation of development characteristics, sensitivity, adhesion, chemical resistance, hue, heat resistance (hue), residual film ratio, and weight loss ratio according to the above-described test methods are shown in Table 3.
Shown in The coating film obtained from the color ink of the present invention is LC
It satisfies the characteristics required for the D color filter ink, and it is recognized that the lightness is particularly high in the required hue and that the ink has excellent heat resistance.

Comparative Example 10 Using the acrylate copolymer resin R-2 of Comparative Example 2, an ink for LCD having the composition shown in Table 4 was prepared. The obtained color ink was spin-coated on a glass substrate coated with SiO ₂ under the condition that the film thickness after post-baking was 1.5 μm, immediately prebaked on a hot plate kept at 80 ° C. for 3 minutes, and tacked. No coating film was obtained. Table 4 shows the results of evaluation of development characteristics, sensitivity, adhesion, chemical resistance, hue, heat resistance (hue), residual film ratio, and weight loss rate according to the above-described test methods. It is recognized that the coating film obtained from the color ink of Comparative Example 10 was inferior in heat resistance to the color ink of the present invention.

[0070]

[Table 4]

[0071]

The alkali-soluble resin of the present invention using (meth) acrylic acid and an alicyclic epoxy group-containing polymerizable unsaturated monomer as essential monomers is superior to the conventional alkali-soluble resin. Demonstrate fine workability and heat resistance. Further, an image forming material using the alkali-soluble resin of the present invention is a protective film material for an electronic device having excellent thermal decomposition resistance,
It has characteristics suitable for insulating film materials and ink resins for LCD color filters. Further, the coating film obtained by curing the image forming material of the present invention is a cured product excellent in residual film ratio, weight loss rate, chemical resistance, transparency, adhesion, hardness, and even smoothness. In addition, it is possible to form a coating film suitable for a protective film material for an electronic device, an insulating film material, an ink resin for an LCD color filter, and the like.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 220/32 C08F 220/32 220/58 220/58 224/00 224/00 290/06 290/06 H01L 21/312 H01L 21/312 D // G02B 5/20 101 G02B 5/20 101 G03F 7/032 501 G03F 7/032 501 7/033 7/033 (72) Inventor Koichi Fujishiro 3-35-1, Ida, Nakahara-ku, Kawasaki-shi, Kanagawa, New Japan Steel Technology Co., Ltd.

Claims (4)

[Claims] 1. A copolymer resin formed from a (meth) acrylic acid component (A) and an alicyclic epoxy group-containing polymerizable unsaturated monomer component (B) as essential monomer components,
(A) is 20 to 45 mol% of all monomer components,
(B) An alkali-soluble resin, wherein (A) is 80 to 200 mol% of (A) and the weight average molecular weight is 1000 or more. 2. The method according to claim 1, wherein an aliphatic polycyclic compound is copolymerized as a monomer component (C) other than (A) and (B) in an amount of 5 mol% or more of all monomer components. Alkali-soluble resin. 3. An image-forming material comprising the alkali-soluble resin according to claim 1 or 2. 4. An image element using the image forming material according to claim 3.