JPH0313582B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a photopolymerizable photosensitive resin composition for image formation.

(Prior art) Conventionally, a resin composition consisting of a binder made of a polymeric material, a photopolymerizable monomer, a photopolymerizable sensitizer, etc. is applied or coated onto a substrate, and active light such as ultraviolet rays is irradiated through a negative image. It is known that the above image can be developed on a substrate by polymerizing or crosslinking the areas exposed to light and making them insoluble in solvents, and eluting the areas not exposed to light. Used for manufacturing wiring boards.

However, the image coating obtained with the above composition has insufficient solvent resistance, chemical resistance, heat resistance and mechanical strength, and its use as a protective coating is limited.

For example, these films can withstand neutral and weakly acidic solutions, but cannot withstand strongly acidic and alkaline solutions, and therefore the types of processing solutions for etching, plating, etc. are limited. Furthermore, it is weak to organic solvents such as toluene, trichlene, and methyl ethyl ketone, and has insufficient heat resistance and mechanical strength, so it cannot be used as a permanent protective film.

Additionally, systems containing epoxy compounds and curing agents have been proposed for the purpose of forming a permanent protective film, but these systems have a short pot life at room temperature, require high temperatures and long periods of time to cure, and may cause the substrate to warp. or cause metal corrosion.

In Japanese Patent Publication No. 52-43092, Japanese Patent Publication No. 52-43091, Japanese Patent Publication No. 56-3539, etc., for the purpose of forming a permanent protective film, an acid component is contained in a copolymer binder to cure it. However, under normal conditions, curing is insufficient, the soldering heat resistance, solvent resistance, and alkali resistance are weak, and furthermore, the cold-heat cycling characteristics are not sufficient.

(Object of the Invention) The present invention solves the above-mentioned conventional drawbacks, and provides a photosensitive resin composition that has excellent storage stability, can be sufficiently cured with short heating, and is suitable for forming a permanent protective film. The purpose is to provide something.

(Summary of the Invention) The present invention comprises (a) a photopolymerizable unsaturated compound having substantially at least two terminal ethylene groups, (b) a photopolymerizable sensitizer, (c) an epoxy acrylate monomer and (meth) )
A polymer compound obtained using a polymerizable compound having a hydroxyl group selected from the group consisting of polyhydric alcohol esters of acrylic acid, and (d) a compound represented by the general formula (), and (R ₁ is an aliphatic hydrocarbon group or aromatic hydrocarbon group, and at least one of R ₂ , R ₃ , and R ₄ is a hydroxyl group, an alkoxyl group, an allyloxy group, an acryloyloxy group, and a methacryloyloxy group) an aliphatic hydrocarbon group containing a group selected from the group consisting of groups, the others are aliphatic hydrocarbon groups or aromatic hydrocarbon groups, and n is an integer of 2 or more) Compounds represented by general formula () (polymer obtained as a component) (R ₅ is an aliphatic hydrocarbon group or aromatic hydrocarbon group having a carbon-carbon double bond, R ₆ , R ₇ ,
At least one of R ₈ is a resinous hydrocarbon group containing a hydroxyl group and a group selected from the group consisting of an alkoxyl group, an allyloxy group, an acryloyloxy group, and a methacryloyloxy group, and the others are aliphatic hydrocarbon groups. group hydrocarbon group or aromatic hydrocarbon group, m is an integer of 1 or more.

The photosensitive resin consists of a compound having two or more aminenomide groups in one molecule selected from the group consisting of, or is characterized by having these as a main component.

(Structure of the Invention) The unsaturated compound (a) in the present invention qualitatively has at least two terminal ethylene groups. Substantially at least 2 means that there is 1 unterminated ethylene group in the system.
There may be compounds with only one terminal ethylene group, and there may be compounds with three or more terminal ethylene groups, and this means that one compound has at least two terminal ethylene groups on average as a whole.

As the unsaturated compound (a), acrylic esters or methacrylic esters of polyhydric alcohols are most suitable. Specifically, triethylene glycol, tetraethylene glycol, ethylene glycol, propylene glycol, trimethylolpropane, Examples include acrylic acid or methacrylic acid esters such as erythritol and neopentine glycol. The amount of this component used is 10 to 90% by weight, preferably 15 to 60% by weight in the photosensitive resin composition.

The sensitizer (b) in the present invention is one that initiates polymerization of the unsaturated compound upon irradiation with actinic light, and in some cases, the main sensitizer and the main sensitizer may be used in combination. .

As the sensitizer (b), conventionally used sensitizers can be used, but phenylketone-based sensitizers are particularly preferred, and specifically, benzophenone,
P-aminophenyl ketones such as P, P-bis(dimethylamino)benzophenone (hereinafter referred to as Michler's ketone), benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin butyl ether, benzoin propyl ether, benzoin isopropyl ether, benzyl anthraquinone, 2 -methyl-anthraquinone,
Examples include 2-ethyl-anthraquinone, 2-t-butyl-anthraquinone, and 2-aminoanthraquinone.

The above-mentioned sensitizers (b) have similar effects, and by combining those with different active light absorption ranges, the polymerization initiation efficiency can be improved and the exposure time can be further shortened. Particularly suitable is a mixture of benzophenone and Michler's ketone. The amount of this component used is 0.01 to 15% by weight in the photosensitive resin composition,
Preferably it is 0.1 to 10% by weight.

Hitherto, as latent curable photosensitive resin compositions that cure by heating, those containing an epoxy compound and its curing agent have been known, but boron trifluoride monoethylamine, boron trifluoride benzylamine complex, tetrafluoroborate, adipic acid, dihydrazide, triethylaminoborane, phenylenediamine-zinc bromide complex,
There are dicyandiamides, etc., but their pot life at room temperature is too short and they cannot be stored.

As a latent curing agent with a long pot life at room temperature, P,
P'-diaminodiphenylenemethane, P,P'-diaminodiphenylsulfonic acid, 2-ethyl-4-ethyl memidazole, etc. have also been found, but they require high temperatures and long periods of time to cure, causing the substrate to warp. This is undesirable because it may cause problems or prolong the processing time.

Further, the above-mentioned conventional latent curing agent is not suitable for manufacturing printed wiring because it diffuses into the substrate with the metal surface and may adversely affect the electrical properties of precision electric circuits.

Therefore, as a result of intensive research, the present inventors have found that a polymeric compound (C) containing a polymerizable compound (C-2) having a hydroxyl group, along with the unsaturated compound (a) and the sensitizer (b), - We have discovered a photosensitive resin composition that uses a polyfunctional amine imide compound (d) having two or more amine imide groups in its molecule.

As the compound (C-2), for example, the following ()
~() Epoxy acrylate monomers obtained by addition reaction of epoxy monomers such as (meth)acrylic acid and polyhydric alcohol esters of (meth)acrylic acid, such as 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl acrylate,
-Hydroxypropyl methacrylate and polyoxyethylene glycol monoacrylate are used.

Polymerizable compound having the above hydroxyl group (C-2)
is polymerized by a conventional method to obtain a polymer compound (C) containing a compound having a hydroxyl group as a component. At this time, in order to improve the film properties of the composition, a second component and a third component may be added to compound (C-2) and polymerized.

Polyfunctional amine imide compound in the present invention
(d) has two or more amine imide groups in one molecule. There are two types of polyfunctional amine imide compounds, one of which is a compound represented by the general formula (), (R ₁ is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
At least one of R ₂ , R ₃ , and R ₄ is a hydroxyl group, an alkoxyl group, or an allyl group.
(It is an aliphatic hydrocarbon group containing a group selected from the group consisting of oxy, acryloyloxy, and methacryloyloxy groups; the others are aliphatic hydrocarbon groups or aromatic hydrocarbons; n is an integer of 2 or more) The other one is a polymer obtained by using a compound represented by the general formula () as a component.

(R ₅ is an aliphatic hydrocarbon group or aromatic hydrocarbon group having a carbon-carbon double bond, and at least one of R ₆ , R ₇ and R ₈ is a hydroxyl group, an alkoxyl group, an allyl group) It is an aliphatic hydrocarbon group containing a group selected from the group consisting of oxy group, acryloyloxy group, and methacryloyloxy group, the others are aliphatic hydrocarbon groups or aromatic hydrocarbon groups, and m is an integer of 1 or more. ) The compound represented by the above general formula () can be obtained, for example, by reacting a polyhydric carboxylic acid ester with a hydrazine derivative, and is represented by the general formula ().
A polymer obtained using the compound represented by as a component can be obtained, for example, by homopolymerizing a reaction product of an unsaturated carboxylic acid ester and a hydrazine derivative, or by copolymerizing the above reaction product with another polymerizable monomer.

Examples of the polycarboxylic acid esters include saturated polycarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, and adipic acid; oxydicarboxylic acids such as malic acid and tartaric acid; maleic acid, fumaric acid, and itaconic acid. Esters such as unsaturated carboxylic acids such as esters, etc. are particularly preferably used.

For example, bis[1,1-dimethyl-1 malonate
-(2-hydroxy-3-allyloxypropyl)
Amineimide], Pissuccinate [1,1-bimethyl-1-(2-hydroxy-3-allyloxypropyl)amineimide], Bisglutarate [1,
1-dimethyl-1-(2-hydroxypropyl)
amine imide], bis maleate [1,1-dimethyl-1-(2-hydroxy-3allyloxypropyl) amine imide], bis itaconate [1,
1-diethyl-1-(2-hydroxypropyl)
amine imide] and the like. Polymers obtained using the compound represented by the general formula () as a component include amine imide homopolymers of monounsaturated carboxylic acids and polyunsaturated carboxylic acids such as acrylic acid and methacrylic acid, various acrylic acids or Copolymers and oligomers with methacrylic acid ester are used, for example, methacrylic acid [1,1
-dimethyl-1-(2-hydroxy-3-butoxy-propyl)amineimide], methacrylic acid [1,1-dimethyl-1-(2-hydroxy-3-
Examples include polymers and copolymers such as (acryloxypropyl)amineimide].

By adding (c) a polymer compound containing a compound having a hydroxyl group and (d) a compound having two or more amine imide groups in one molecule, the heat resistance and chemical resistance of the cured film can be improved. In addition, bleed-out properties are also suppressed, flexibility is imparted to the polymer compound (c), low-temperature shrinkability is improved, and cold-heat cycling properties are improved. Although the reason for these is not clear, the hydroxyl group in the polymer compound (c) and the compound (d)
Alternatively, it is thought that the decomposition products react, develop a three-dimensional structure, and generate urethane bonds that provide flexibility.

As for the compound (d), those in which R ₁ in the general formula () contains a carbon-carbon double bond have better cold-heat cycle properties, and those obtained by polymerizing or copolymerizing the general formula () have even better cold-heat cycle properties. is excellent. In addition, R ₂ , R ₃ , R ₄ of general formula () and general formula ()
Those in which R ₆ , R ₇ , and R ₈ are aliphatic hydrocarbons having 8 or less carbon atoms have excellent hardenability and heat resistance, and carbon-
Those containing carbon double bonds also have excellent curability and heat resistance. The reason for this is not clear, but it does not bleed out and have a negative effect on the substrate surface, and it improves solvent resistance, acid resistance, and alkali resistance by being incorporated into the polymerization system by irradiation with active light. It seems to be for a reason.

The polymer compound (c) has a molecular weight of 50,000 to 600,000, optimally 100,000 to 300,000, and preferably 10 to 90% by weight, preferably 30 to 70% by weight of the composition.

The amine imide component of compound (d) is preferably 1 to 30% by weight in the composition.

In addition to the above-mentioned essential components, the photosensitive resin composition of the present invention can further contain secondary components for various purposes. That is, it is possible to contain a thermal polymerization inhibitor for improving storage stability, a plasticizer for improving film properties, an adhesion improver, a dye, a pigment, other fillers, and the like.

(Action of the invention) The photosensitive resin composition of the present invention has photosensitivity like conventional photosensitive resins, undergoes photopolymerization when irradiated with actinic light, and is sufficiently thermally stable at temperatures below 80°C. A permanent protective coating can be formed using conventional methods.

That is, the photosensitive resin composition of the present invention is usually 3 to 60
Adjust the solution by dissolving it in an organic solvent such as methyl ethyl ketone, toluene, methyl cellosolve, or chloroform to a concentration of % by weight, and follow the steps below (1).
Alternatively, a photosensitive layer is formed on the substrate to be protected by method (2).

(1) A solution containing a photosensitive resin composition is applied onto a substrate and dried.

(2) A solution containing the photosensitive resin composition is applied to a film such as polyethylene terephthalate and dried. The obtained film is attached to a substrate using a hot roll. In this case, a protective film may be superimposed on the film photosensitive layer.

The substrate on which the photosensitive layer is formed is irradiated with active light such as ultraviolet rays through a negative mask, and the exposed areas are cured by photopolymerization and crosslinking. Then 1, 1, 1
- Using trichloroethane or the like, unexposed areas are eluted and developed.

The image-like protective film obtained in this way becomes a corrosion-resistant film for ordinary surface modification processing such as etching and plating, but it can also be heat-resistant and mechanically Creates a strong, permanent protective coating. This protective film is not attacked by aromatic hydrocarbons such as toluene, ketone solvents such as methyl ethyl ketone, halogenated hydrocarbon solvents such as methylene dichloride, and is sufficiently resistant to strong acids and aqueous alkaline solutions. Therefore, it can be used as a permanent protective film such as a solder resist with excellent soldering heat resistance. A protective film having excellent strength can also be formed by post-exposure to ultraviolet light or the like at an intensity of 1 to 3 J/cm ² prior to heat curing.

Furthermore, since the photosensitive resin composition of the present invention has excellent photosensitivity and chemical and physical strength, it can be used as a photosensitive paint,
Also used as plastic relief and printing plate material.

(Example) Examples of the present invention will be described below.

In addition, "parts" means parts by weight.

Example 1 Methyl methacrylate/β-hydroxyethyl methacrylate (95/5) copolymer (weight average molecular weight 200,000) 60 parts Pentaerythritol triacrylate 30 parts Benzophenone 3 parts Michler's ketone 0.5 part P-methoxyphenol 0.5 part Bis malonate [ 2 parts of 1,1-dimethyl-1-(2-hydroxypropyl)amineimide (d-A) 200 parts of methyl ethyl ketone The photosensitive resin composition obtained with the above formulation was coated and dried on a 25 μm polyethylene terephthalate film to a thickness of 75 μm. The photosensitive layer was The layers were heated and laminated on a cleaned copper plate using a hot roll, and irradiated with ultraviolet rays from a 100 mJ/cm ² high-pressure mercury lamp through a negative mask. Next, the polyethylene terephthalate film was peeled off, and 1,1,1-trichloroethane was sprayed for 90 seconds to elute the unexposed areas and development was performed. Next, heat treatment was performed at 150° C. for 10 minutes, and a protective film with a precise image corresponding to a negative mask was obtained.

This protective coating is made of methyl ethyl ketone, acetone, chloroform, trichlene, methanol, 10
1% each in sulfuric acid aqueous solution, toluene, and xylene
There was no change even after immersion for several days, and the pH remained at 70℃.
No abnormality was observed even after immersion in the sodium hydroxide aqueous solution of No. 12 for one day.

Further, there was no change even after repeated cooling and heating at -65°C and 125°C at 60 minute intervals, and further immersion in a 260-270°C solder bath for 2 minutes. Even when the substrate on which the cured film was formed was left at 70°C for one month, no bleed-out was observed on the surface, and even when the photosensitive layer was stored at 40°C for six months, there was no problem with its use.

From the above, it was found that the obtained protective film can be satisfactorily used as a resist for etching, plating, strong alkaline electroless plating, and as a solder resist that requires soldering heat resistance.

Example 2 In place of 2 parts of malonate bis[1,1-dimethyl-1-(2-hydroxypropyl)amineimide in Example 1, maleate bis[1,1-dimethyl-1-(2-hydroxy-3 A photosensitive resin was prepared and tested in the same manner as in Example 1 except that 2 parts of -allyloxypropylene)amineimide were used.

The solvent resistance, chemical resistance, solder bath resistance, and storage stability of the photosensitive layer were all the same as in Example 1, and the sample withstood 175 cycles in the cold/heat cycle test.

Example 3 Methyl methacrylate/triethylene glycol monomethacrylate (85/15) copolymer (weight average molecular weight 180,000) 59.5 parts Pentaerythritol triacrylate 30 parts Benzoin isopropyl ether 5 parts P-methoxyphenol 0.5 parts Methyl methacrylate/1, 1-dimethyl-1-
(2-Hydroxy-3-butoxypropyl)amine methacrylimide (5/1) copolymer (weight average molecular weight 20,000) 5 parts Methyl ethyl ketone 2 million parts The composition obtained with the above formulation was prepared and Tests were conducted in the same manner.

The solvent resistance, chemical resistance, solder bath resistance, and storage stability of the photosensitive layer were all the same as in Example 1, and the sample withstood 180 cycles in the cold/heat cycle test.

Comparative example Methyl methacrylate/glycidyl methacrylate (60/40) copolymer (weight average molecular weight 250,000)
60 parts pentaerythritol triacrylate 30 parts benzophenone 3 parts Michler's ketone 0.5 part P-methoxyphenol 0.5 part methyl ethyl ketone 200 parts and dicyandiamide 2 as an epoxy hardener
The same test as in Example 1 was carried out by adding 1.0 parts.
After exposure and development, heating at 150°C for 10 minutes did not provide a sufficiently cured film, and the film had almost no solvent resistance or heat resistance. When heated at 150°C for 2 hours, it was able to withstand various organic solvents for several tens of minutes, but cracks occurred within 5 times in repeated cold and heat tests.
Furthermore, when the unirradiated, uncured film was stored at 40°C, it was found to harden in just one week, indicating that the visible time was short.

(Effects of the Invention) As described above, the photosensitive resin composition of the present invention has excellent storage stability, the reaction proceeds sufficiently at a relatively low temperature in a short period of time during curing, and has excellent solvent resistance, alkali resistance, A protective film with good heat resistance can be formed.

Claims (1)

[Scope of Claims] 1 (a) Substantially at least 2 terminal ethylene groups
(b) a photopolymerizable sensitizer, (c) an epoxy acrylate monomer and (meth)
A polymer compound obtained using a polymerizable compound having a hydroxyl group selected from the group consisting of polyhydric alcohol esters of acrylic acid, and (d) a compound represented by the general formula (), and (R ₁ is an aliphatic hydrocarbon group or aromatic hydrocarbon group, and at least one of R ₂ , R ₃ , and R ₄ is a hydroxyl group, an alkoxyl group, an allyloxy group, an acryloyloxy group, and a methacryloyloxy group) an aliphatic hydrocarbon group containing a group selected from the group consisting of groups, the others are aliphatic hydrocarbon groups or aromatic hydrocarbon groups, and n is an integer of 2 or more) Compounds represented by general formula () Polymer obtained as a component (R ₅ is an aliphatic hydrocarbon group or aromatic hydrocarbon group having a carbon-carbon double bond, R ₆ , R ₇ ,
At least one of R ₈ is an aliphatic hydrocarbon group containing a hydroxyl group and a group selected from the group consisting of an alkoxyl group, an allyloxy group, an acryloyloxy group, and a methacryloyloxy group, and the others are aliphatic hydrocarbon groups. consisting of a compound having two or more amine imide groups in one molecule selected from the group consisting of a group hydrocarbon group or an aromatic hydrocarbon group, where m is an integer of 1 or more, or having these as the main component. Characteristic photosensitive resin composition.