JP4597145B2 - Active energy ray polymerization initiator, polymerizable composition containing the same, and cured product thereof - Google Patents

Description

The present invention relates for example active energy Senkasane initiator used as a raw material for forming the active energy ray-curable coating material such as an ultraviolet polymerizable composition and a cured product containing the same.

Conventionally, as this kind of technique, a crosslinking agent comprising a Michael adduct of polyfunctional (meth) acrylate and t-butyl acetoacetate is known (see, for example, Patent Document 1). This cross-linking agent can cure the hydroxyl group-containing thermosetting resin used in various paints and the like. Further, a photocurable composition containing a resin having a chemical structure portion selected from an acryloyl group and a β-ketoester group or a β-diketone group is known (see, for example, Patent Document 2). In this photocurable composition, the β-ketoester group or β-diketone group has a quaternary carbon atom that can generate one or two free radicals by light irradiation.
JP 7-48472 A (pages 2 and 4) JP 2003-268025 A (2nd and 10th pages)

  In the crosslinking agent described in Patent Document 1, a quaternary carbon atom generated by Michael addition reaction of a polyfunctional (meth) acrylate with an active methylene group generates a radical by light irradiation, and functions as a photopolymerization initiator. To do. Also in the photocurable composition described in Patent Document 2, the β-ketoester group or β-diketone group has a quaternary carbon atom, and one or two free radicals are generated by light irradiation. However, in these crosslinking agents and photopolymerizable compositions, the Michael addition reaction product has a monomer (monomer) or oligomer structure. For this reason, in addition to a crosslinking reaction and a photocuring reaction, a radical polymerization reaction is very likely to occur. Therefore, the conventional crosslinking agents and photopolymerizable compositions have a problem that they are easily gelled and lack storage stability.

Therefore it is an object of the present invention can express a good active energy ray polymerization initiating ability, is excellent in curability, suppressing gelation, the active energy Senkasane initiator capable of improving the storage stability, It is providing the polymeric composition containing it, and its hardened | cured material.

To achieve the above object, an active energy Senkasane initiator of claim 1, represented by the chemical formula (1), an acrylic resin, β- keto ester groups in the polyester resin or alkyd resin bound It is characterized by that.

但し、Ｒは、Ｒ^１−Ｏ−を表し、Ｒ ^１ はアクリル樹脂、ポリエステル樹脂又はアルキッド樹脂のβ−ケトエステル基以外の部分を示す。

Here, R ^is, R 1 -O - represents, ^{R 1} is shows a portion other than β- ketoester group of the acrylic resin, a polyester resin or alkyd resin.

The active energy Senkasane initiator according to claim 2 is the invention according to claim 1, the content of β- ketoester groups, is ^{2.0 × 10 -4 ~5.0 × 10 -3} mol / g It is characterized by that.

The active energy Senkasane initiator according to claim 3, in the invention according to claim 1 or claim 2, beta-ketoester groups, are those which are introduced by polymerization of (meth) acrylate having an acetoacetoxy group It is characterized by.

The active energy Senkasane initiator according to claim 4 is the invention according to any one of claims 1 to 3, wherein the acrylic resin, a portion other than β- ketoester groups of the polyester resin or alkyd resin has a hydroxyl group It is characterized by not.

Polymerizable composition having an active energy ray polymerization initiation ability of claim 5, only the active energy Senkasane initiator as claimed in any one of claims 4 as a polymerization initiator, an active energy ray And a curable monomer.

  The polymerizable composition having active energy ray polymerization initiating ability according to claim 6 is the invention according to claim 5, wherein the monomer having active energy ray curability is a compound having a (meth) acryloyl group. Features.

  A cured product according to claim 7 is a coating film obtained by applying the polymerizable composition having the ability to initiate active energy ray polymerization according to claim 5 or 6 onto a substrate, and irradiating and curing the active energy ray. It is formed.

The cured product according to claim 8 is the invention according to claim 7, wherein only the active energy ray polymerization initiator according to claim 5 or 6 and a monomer having active energy ray curability are formed on the film. It is characterized by coating an active energy ray-curable composition other than the polymerizable composition having an ability to initiate active energy ray polymerization, and forming an overcoat layer by irradiating and curing the active energy ray. To do.

  The cured product according to claim 9 is the invention according to claim 8, wherein the active energy ray-curable composition contains a photopolymerization initiator.

According to the present invention, the following effects can be exhibited.
The active energy Senkasane initiator of claim 1, wherein is represented by the formula (1), an acrylic resin, β- keto ester groups in the polyester resin or alkyd resin bonded. The β- The ketoester group acrylic resin as R ^1, from the fact that include only the β- ketoester groups of the polyester resin or alkyd resin, the electron density of the methylene groups of β- ketoester group is increased, unstable It is predicted that the active energy ray polymerization initiating ability is expressed, and radicals are generated by irradiation of the active energy ray. Therefore, good active energy ray polymerization initiating ability can be expressed and excellent curability can be exhibited. Furthermore, in the polymerizable composition containing a β-ketoester group , R ¹ is not a monomer or oligomer, but is a portion other than the β-ketoester group of an acrylic resin, a polyester resin, or an alkyd resin. It can be suppressed and storage stability can be improved.

The active energy Senkasane initiator according to claim 2, the content of beta-ketoester groups, since it is ^{2.0 × 10 -4 ~5.0 × 10 -3} mol / g, β- ketoester group The effect of the invention according to claim 1 can be sufficiently exhibited.

The active energy Senkasane initiator according to claim 3, beta-keto ester group is intended to be introduced by the polymerization of (meth) acrylate having an acetoacetoxy group. For this reason, in addition to the effect of the invention according to claim 1 or claim 2, a β-ketoester group can be easily introduced based on the acetoacetoxy group.

The active energy Senkasane initiator of claim 4, wherein the acrylic resin, since the portion other than β- ketoester groups of the polyester resin or alkyd resins are those having no hydroxyl group, claims 1 to 3 In addition to the effects of the invention according to any of the above, polymerization inhibition due to hydroxyl groups can be avoided, and excellent curability can be exhibited.

Polymerizable composition having an active energy ray polymerization initiation ability of claim 5, only the active energy Senkasane initiator as the polymerization initiator, those which contain a monomer having an active energy ray-curable . For this reason, in addition to the effect of the invention according to any one of claims 1 to 4, the monomer having active energy ray curability can easily start polymerization with active energy rays by the action of the polymerization initiator. Can do.

  In the polymerizable composition having active energy ray polymerization initiating ability according to claim 6, since the monomer having active energy ray curability is a compound having a (meth) acryloyl group, the effect of the invention according to claim 5 is achieved. In addition, the polymerizability by active energy rays can be further improved based on the (meth) acryloyl group.

  A cured product according to claim 7 is a coating film obtained by applying the polymerizable composition having the ability to initiate active energy ray polymerization according to claim 5 or 6 onto a substrate, and irradiating and curing the active energy ray. It is formed. Therefore, this hardened | cured material can exhibit the effect of the invention which concerns on Claim 5 or Claim 6.

Cured product of claim 8, on the film, the active energy ray polymerization initiator containing an active energy ray polymerization initiator only a monomer having an active energy ray curable claim 5 or claim 6 An active energy ray-curable composition other than a polymerizable composition having a function is applied, and an active energy ray is irradiated and cured to form an overcoat layer. Therefore, in addition to the effect of the invention according to claim 7, the overcoat layer can be cured by the β-ketoester group contained in the layer first coated on the substrate.

  In the cured product of claim 9, since the active energy ray-curable composition contains a photopolymerization initiator, in addition to the effect of the invention according to claim 8, the overcoat layer can be easily cured. it can.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments embodying the present invention will be described in detail.
The active energy Senkasane initiator of the present embodiment (hereinafter, simply referred to as polymerization initiator) is represented by the chemical formula (1), an acrylic resin, by bonding β- ketoester groups in the polyester resin or alkyd resin It is what.

但し、Ｒは、Ｒ^１−Ｏ−を表し、Ｒ ^１ はアクリル樹脂、ポリエステル樹脂又はアルキッド樹脂のβ−ケトエステル基以外の部分（以下、樹脂骨格の残基ともいう）を示す。なお、β−ケトエステル基は、化学式（１）におけるＲ ^１ 以外の部分を指す。これらのβ−ケトエステル基には樹脂骨格の残基が含まれていることから、β−ケトエステル基のメチレン基に基づいて活性エネルギー線重合開始能が発揮されるものと考えられる。

Here, R is, R 1 ^-O - represents, R ¹ is shows a portion other than β- ketoester group of the acrylic resin, a polyester resin or alkyd resin (hereinafter also referred to as residues of the resin backbone). Incidentally, beta-ketoester group refers to ^{R 1} other than the portion in the chemical formula (1). Since these β-ketoester groups contain residues of the resin skeleton, it is considered that the active energy ray polymerization initiating ability is exhibited based on the methylene group of the β-ketoester group .

It is not particularly restricted but includes resin for forming the resin skeleton of R ^1, acrylic resins, polyester resins or alkyd resins. The mass average molecular weight of the resin skeleton is preferably 3,000 to 50,000, and more preferably 9,000 to 45,000. When the mass average molecular weight is less than 3,000, the electron donating property by the resin skeleton cannot be sufficiently obtained, and the active energy ray polymerization initiating ability based on the methylene group is not preferable. On the other hand, when the mass average molecular weight exceeds 50,000, the molecular weight of the resin skeleton becomes too large, which may hinder the ability to initiate active energy ray polymerization.

Wherein the polymerization initiator as a method for introducing a chemical structure part of β- ketoester groups, and methods according to the polymerization of the monomer forming the β- ketoester group, the monomers alcohol exchange to form the β- ketoester group And a method of introducing it into the resin skeleton. As the monomer that forms a β-ketoester group, (meth) acrylate having an acetoacetoxy group (CH ₃ COCH ₂ CO ₂ O— ) is preferable because a β-ketoester group can be easily introduced.

As the former method, for example, a (meth) acrylate having an acetoacetoxy group is blended with other monomers and a normal polymerization initiator such as 1-azobiscyclohexane-1-carbonitrile (ACHN) as necessary. The polymerization reaction is carried out by heating in an organic solvent according to a conventional method. As the (meth) acrylate having an acetoacetoxy group, 2-acetoacetoxyethyl methacrylate (AAEM), 2-acetoacetoxyethyl acrylate (AAEA), acetoacetoxybutyl acrylate (AABA), or the like is used. Such other monomer, methylation methacrylate (MMA), butyl acrylate (BA), lauryl methacrylate (LMA), 2-hydroxyethyl methacrylate (HEMA), tridecyl (meth) acrylate, myristyl (meth) acrylate, cetyl ( Meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, stearoxy polyethylene glycol mono (meth) acrylate, or the like is used. As the organic solvent, methyl isobutyl ketone (MIBK), ethyl acetate, toluene, isopropyl alcohol, propylene glycol and the like are used. As the polymerization initiator, 1-azobiscyclohexane-1-carbonitrile (ACHN) or the like is used.

  As the latter method, for example, t-butyl alcohol produced by heating t-butylacetylacetate (TBAA) and acrylic polyol in the presence of triphenylphosphine (TPP) as a catalyst to perform an alcohol exchange reaction. It is a method to collect. By this method, an acrylic resin having an acetoacetoxy group introduced into an acrylic polyol is obtained. In addition, a polyester resin having an acetoacetoxy group introduced can be obtained by using a polyester polyol instead of the acrylic polyol. Furthermore, by using an alkyd polyol instead of the acrylic polyol, an alkyd resin into which an acetoacetoxy group is introduced can be obtained.

The β-ketoester group content is preferably 2.0 × 10 ^{−4 to} 5.0 × 10 ⁻³ mol / g. When the content of the β-ketoester group is less than 2.0 × 10 ⁻⁴ mol / g, the active energy ray polymerization initiation ability based on the methylene group of the β-ketoester group is not sufficiently exhibited, which is not preferable. On the other hand, when it exceeds 5.0 × 10 ⁻³ mol / g, the active energy ray polymerization initiation ability is increased, but the selection of the type of monomer that forms the β-ketoester group, the setting of the polymerization conditions, etc. Tend to be difficult.

The β-ketoester group is preferably introduced by polymerization of (meth) acrylate having an acetoacetoxy group, particularly acetoacetoxyethyl (meth) acrylate, as described above. In this case, the β-ketoester group can be most easily introduced into the polymerization initiator based on the acetoacetoxy group of the (meth) acrylate.

The resin skeleton in the active energy Senkasane initiator preferably does not have a hydroxyl group. When the resin skeleton has a hydroxyl group, the hydroxyl value is preferably 50 mgKOH / g or less. When the hydroxyl value exceeds 50 mgKOH / g, the radical cleavage of the polymerization initiator becomes difficult due to the hydroxyl group, the polymerization is inhibited, and the tendency to lower the polymerization initiation function becomes strong.

Next, the polymerizable composition having an active energy ray polymerization initiation ability are those containing the above active energy Senkasane initiator, a monomer having an active energy ray-curable. A monomer having active energy ray curability can be polymerized by irradiation of active energy rays by the action of a polymerization initiator. The monomer having active energy ray-curing property is a monomer having two or more (preferably three or more) active energy ray-curable functional groups in one molecule. As the monomer having active energy ray curability, a compound having a (meth) acryloyl group having high polymerizability by active energy rays is preferable. Here, in this specification, acryl and methacryl are collectively referred to as (meth) acryl.

  Examples of the compound having a (meth) acryloyl group include urethane (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, and isocyanuric acid ethylene oxide modification. Di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropane 3 mol propylene oxide adduct tri (meth) acrylate, trimethylolpropane 6 mol ethylene oxide adduct Hexa (meth) acrylate of caprolactone adduct of tri (meth) acrylate, glycerin propoxytri (meth) acrylate, dipentaerythritol And the like.

  Active energy ray polymerizable compositions include UV absorbers, light stabilizers, organic solvents, thickeners, antifoaming agents, plasticizers, film-forming aids, pigments, fillers, aggregates, dispersants, preservatives. A rust inhibitor and the like can be appropriately blended depending on the purpose. As the ultraviolet absorber, a benzotriazole-based compound or the like is used. As the light stabilizer, piperidine-based or hindered amine-based compounds are used. As the organic solvent, compounds such as alcohols, esters and aromatics are used.

  Next, the cured product by active energy rays is coated on the substrate with the polymerizable composition having the above-mentioned active energy ray polymerization initiating ability, and the polymerizable composition is cured by irradiating active energy rays. A film (coating film) is formed on the material. Although it does not restrict | limit especially as a base material, Specifically, Electronic parts, such as a mobile telephone, a wristwatch, a compact disk, an audio equipment, OA equipment, etc .; Electronic parts, such as a touchscreen and the reflection prevention board of a cathode ray tube; A refrigerator, a vacuum cleaner, Home appliances such as microwave ovens; instrument panels, dashboards, bumpers, spoilers, door knobs, handles, headlamps, motorcycle gasoline tanks, aluminum wheels, door mirrors and other automotive interior and exterior parts; carport roofs, daylighting roofs; Examples include resin molded products such as vinyl resin, acrylic resin, polyester resin, polycarbonate resin, and ABS resin; woodwork products such as stairs, floors, desks, chairs, chests, and other furniture; cloth, paper, and the like.

  The coating method may be in accordance with an ordinary method, and examples thereof include an air spray method, an airless spray method, an electrostatic coating method, a roll coater method, a flow coater method, and a spin coat method. The thickness of the coating is preferably about 1 to 100 μm. When the thickness of the coating is less than 1 μm, the function of the coating such as protecting the substrate surface cannot be fully exhibited. On the other hand, if the thickness exceeds 100 μm, the coating becomes too thick and the properties of the substrate cannot be fully exhibited.

As the curing means, a method of irradiating active energy rays such as ultraviolet rays and electron beams is adopted. In the case of the method of irradiating with ultraviolet rays, it is preferable to use a mercury lamp, a metal halide lamp or the like, and it is preferable to irradiate ultraviolet rays with an integrated light quantity of 100 to 1000 mJ / cm ² . On the other hand, when curing by irradiating an electron beam, it is preferable to irradiate an electron beam of 1 to 5 Mrad at an acceleration voltage of 150 to 250 keV.

As the cured product, an active energy ray-curable composition other than the polymerizable composition having active energy ray polymerization initiation ability is further applied on the film (undercoat layer) formed on the base material, An overcoat layer may be formed by irradiating and curing energy rays. In this case, since it is possible to cure the more overcoat layer β- ketoester group contained in the polymerizable composition for forming an undercoat layer, without adding a new polymerization initiator to cure the overcoat layer May be. The material for forming the undercoat layer may be either the polymerization initiator or the polymerizable composition. Moreover, after applying the material which forms an undercoat layer, you may irradiate an active energy ray, but the direction which does not irradiate can promote hardening of an overcoat layer.

  In addition, in order to improve the active energy ray sclerosis | hardenability of an undercoat layer or an overcoat layer, it is also possible to mix | blend a photoinitiator. Examples of such photopolymerization initiators include isopropyl benzoin ether, isobutyl benzoin ether, benzophenone, Michler ketone, o-benzoylmethyl benzoate, acetophenone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, ethyl anthraquinone, p-dimethylamino. Benzoic acid isoamyl ester, p-dimethylaminobenzoic acid ethyl ester, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2,2-dimethoxy-1,2-diphenyl Ethane-1-one, 2-benzyl-2-dimethylamino-1 (4-morpholinophenyl) -butanone-1, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, Such as chill benzyl formate and the like.

  Applications of the cured product include coating films with paints, coating films with coating agents, etc., but other light reflecting films, antireflection films, polarizing films, light diffusing films, lens sheets, ultraviolet shielding films, electromagnetic shielding films. Etc. That is, the active energy ray-polymerizable composition of the present embodiment can be used for each of the above applications by curing it in a predetermined shape or by applying it to the surface of a substrate and curing it.

Now, to explain the action of this embodiment, the active energy Senkasane initiator, for example obtained by polymerization of monomers comprising acetoacetoxy ethyl (meth) acrylate. The resulting polymerization initiator contains a β-ketoester group represented by the chemical formula (1). It is speculated that these β-ketoester groups are bonded to the residue of the resin skeleton, the electron density of the methylene group of the β-ketoester group is increased, destabilized, and active energy ray polymerization initiation ability is expressed. The Then, it is considered that when the active energy ray-curable monomer is irradiated with active energy rays using this polymerization initiator, radicals are generated and the polymerization is rapidly started.

The effects exhibited by the above embodiment will be described collectively below.
-The polymerization initiator of this embodiment is represented by the said Chemical formula (1), and (beta) -ketoester group is couple | bonded with the acrylic resin, the polyester resin, or the alkyd resin . Based on this β-ketoester group, good active energy ray polymerization initiating ability can be expressed, and excellent curability can be exhibited. Furthermore, in the polymerizable composition containing a β-ketoester group, since R 1 is not a monomer or an oligomer but a residue of a resin skeleton, gelation is suppressed and storage stability can be improved. it can. In addition, since the monomer having active energy ray curability can be polymerized by this polymerization initiator, there is no need to add a normal polymerization initiator, and the weather resistance of the resulting cured product can be improved. it can.

  -Since a polymerization initiator is a polymeric polymerization initiator as represented by the said Chemical formula (1), it has low volatility and can suppress an odor. Moreover, the content of the monomer or low molecular weight compound in the cured product obtained by polymerizing the active energy ray monomer using such a polymerization initiator or on the surface thereof can be reduced, and contamination on the surface can be achieved. (Adhesion) can be suppressed.

Such a polymerization initiator does not need to be subjected to a Michael addition reaction to an active methylene group, and is obtained by a normal radical polymerization method, so that it is very easy to produce.
-When the content of β-ketoester group in the polymerization initiator is 2.0 × 10 ^{−4 to} 5.0 × 10 ⁻³ mol / g, β-ketoester group is ensured, and the above effect is obtained. Can fully demonstrate.

Polymerization initiators, beta-keto ester group, by being introduced in the polymerization of (meth) acrylate having an acetoacetoxy group, the easy introduction of beta-ketoester group on the polymerization initiator based on the acetoacetoxy groups Can do.

  -Since the resin skeleton of the polymerization initiator does not have a hydroxyl group, polymerization inhibition based on the difficulty of radical cleavage of the polymerization initiator by the hydroxyl group can be avoided, and excellent curability is maintained. be able to.

In the polymerizable composition, since it contains only the active energy ray polymerization initiator as a polymerization initiator and a monomer having active energy ray curability, the monomer having active energy ray curability is Polymerization can be easily initiated by active energy rays by the action of the polymerization initiator.

  In the polymerizable composition, the monomer having active energy ray curability is a compound having a (meth) acryloyl group, thereby further improving the polymerizability by the active energy ray based on the (meth) acryloyl group. be able to.

  -Moreover, hardened | cured material is a thing formed by coating said polymeric composition on a base material, irradiating an active energy ray, and making it harden | cure. And the effect of the said polymerization initiator can be exhibited about this hardened | cured material.

- In addition, the cured product, coating the active energy Senkasane initiator and the active energy ray radiation curable composition other than the polymerizable composition containing a monomer having a curable on the film Then, an active energy ray is irradiated and cured to form an overcoat layer. Therefore, it is possible to cure the more overcoat layer β- ketoester groups contained in the first coated layers on the substrate.

  -In this hardened | cured material, since the said active energy ray curable composition contains a photoinitiator, an overcoat layer can be hardened | cured easily.

Hereinafter, the embodiment will be described in more detail with reference to examples and comparative examples, but the invention is not limited to these examples. In addition, unless otherwise indicated, the part and% in each example show a mass part and mass%.
(Synthesis of AABA)
A four-necked flask equipped with a stirrer, thermometer, condenser and nitrogen gas inlet tube was charged with 100 parts of 4-hydroxybutyl acrylate, 100 parts of ethyl acetate and 0.5 part of triethylamine, and the temperature was raised to 40 ° C. Got. While maintaining the liquid temperature at 40 to 45 ° C., 50 parts of diketene was added dropwise to the ethyl acetate mixed solution over 4 hours. After completion of dropping, the reaction was carried out at the same temperature for 3 hours. Furthermore, after completion | finish of reaction, it wash | cleaned using 0.2% hydrochloric acid aqueous solution and ion-exchange water in order, Then, it dried with anhydrous sulfuric acid, the solvent was depressurizingly distilled and the acetoacetoxy butylacrylate (AABA) was obtained.
Example 1
A four-necked flask equipped with a stirrer, a thermometer, a condenser and a nitrogen gas inlet tube was charged with 100 parts of methyl isobutyl ketone (MIBK) and heated to 117 ° C. On the other hand, 100 parts of 2-acetoacetoxyethyl methacrylate (AAEM, manufactured by Eastman Chemical Co., Ltd.) and 2 parts of 1-azobiscyclohexane-1-carbonitrile (ACHN) were mixed and added to the methyl isobutyl ketone over 2 hours. It was dripped. Acrylic resin 1 was obtained as a polymerization initiator having active energy ray polymerization initiating ability by reacting at the same temperature for 8 hours after completion of the dropping. This acrylic resin 1 had a structure in which a β-ketoester group was bonded to the residue of the acrylic resin skeleton.
(Examples 2-9)
In Examples 2-4, it replaced with 2-acetoacetoxyethyl methacrylate (AAEM) in Example 1, and used AAEM and methyl methacrylate (MMA) by content shown in Table 1, and others are the same as Example 1 Thus, acrylic resins 2 to 4 were prepared. In Examples 5 and 6, instead of AAEM in Example 1, AAEM, methyl methacrylate (MMA), and 2 -hydroxyethyl methacrylate (HEMA) were used in the contents shown in Table 1, and the others were Example 1. In the same manner, acrylic resins 5 and 6 were prepared.

In Example 7, instead of AAEM in Example 1, 2-acetoacetoxyethyl acrylate (AAEA, manufactured by Nippon Synthetic Chemical Co., Ltd.), MMA, and lauryl methacrylate (LMA) were used in the contents shown in Table 1. Otherwise, acrylic resin 7 was prepared in the same manner as in Example 1. In Example 8, instead of AAEM in Example 1, AAEM, AAEA, MMA, butyl acrylate (BA), and LMA were used in the contents shown in Table 1, and the others were the same as in Example 1. Thus, an acrylic resin 8 was prepared. In Example 9, instead of AAEM in Example 1, AABA, AAEA, MMA, BA, and LMA were used in the contents shown in Table 1, and the others were the same as in Example 1, except that acrylic resin 9 Was prepared. These acrylic resins 2 to 9 had a structure in which a β-ketoester group was bonded to the residue of the acrylic resin skeleton.
(Comparative Example 1)
100 parts of MIBK was charged into a four-necked flask equipped with a stirrer, a thermometer, a condenser and a nitrogen gas introduction tube, and the temperature was raised to 117 ° C. On the other hand, 80 parts of MMA, 20 parts of LMA and 2 parts of ACHN were mixed and dropped into the MIBK over 2 hours. After completion of dropping, an acrylic resin 10 was obtained by reacting at the same temperature for 8 hours.
(Example 10, introduction of acetoacetoxy group into acrylic polyol)
In a four-necked flask equipped with a stirrer, thermometer, condenser and air introduction tube, 26.7 parts of t-butylacetylacetate (TBAA, manufactured by Eastman Chemical Co., Ltd.), acrylic polyol (manufactured by Toagosei Co., Ltd., UH) -2032, hydroxyl value: 110) 85.8 parts and triphenylphosphine (TPP) 0.5 parts were charged, and the temperature was raised to 110-120 ° C. under air bubbling to carry out an alcohol exchange reaction. And the acrylic resin 11 by which the acetoacetoxy group was introduce | transduced into the acrylic polyol was obtained by making it react at the same temperature for 5 hours, collect | recovering the produced | generated t-butyl alcohol. The conversion rate calculated from the recovered solvent (unreacted material) was 78%.
(Example 11, introduction of acetoacetoxy group into polyester polyol)
In a four-necked flask equipped with a stirrer, a thermometer, a condenser and an air introduction tube, 37.21 parts of TBAA, polyester polyol (C-1000, hydroxyl value: 160, manufactured by Mitsui Chemicals Polyurethane Co., Ltd.), 82.58 parts, 0.5 parts of TPP was charged, and the alcohol exchange reaction was performed by raising the temperature to 110 to 120 ° C. under air bubbling. And the polyester resin by which the acetoacetoxy group was introduce | transduced into the polyester polyol was obtained by making it react at the same temperature for 5 hours, collect | recovering the produced | generated t-butyl alcohol. The conversion calculated from the recovered solvent was 85%. This polyester resin had a structure in which a β-ketoester group was bonded to the residue of the polyester resin skeleton.
(Example 12, introduction of acetoacetoxy group into alkyd polyol)
A four-necked flask equipped with a stirrer, a thermometer, a condenser and an air introduction tube was charged with 29.18 parts of TBAA, 86.33 parts of alkyd polyol (hydroxyl value: 120), and 0.5 parts of TPP under air bubbling. The temperature was raised to 110 to 120 ° C. to perform an alcohol exchange reaction. And alkyd resin by which the acetoacetoxy group was introduce | transduced was obtained by making it react at the same temperature for 5 hours, collect | recovering the produced | generated t-butyl alcohol. The conversion calculated from the recovered solvent was 72%. This alkyd resin had a structure in which a β-ketoester group was bonded to the residue of the alkyd resin skeleton.
(Comparative Example 2, synthesis of oligomer)
A four-necked flask equipped with a stirrer, a thermometer, a condenser, and an air introduction tube is equipped with 296.0 parts of trimethylolpropane triacrylate (TMPTA, manufactured by Daicel Cytec Chemical Co., Ltd.), acetylacetone (manufactured by Daicel Chemical Industries, Ltd., AcAc). ) 50.0 parts and diazabicycloundecene (DBU) 2.0 parts were charged, heated to 80 ° C. and stirred at the same temperature for 4 hours to be reacted. And it diluted with 346.0 parts of MIBK, and obtained the oligomer of 50% of solid content.

About the above acrylic resin, polyester resin, alkyd resin, and oligomer, the mass average molecular weight (Mw), the hydroxyl group (OH) value, the resin stability, and the content of β-ketoester groups are measured by the methods shown below, together with the composition. The results are shown in Table 1.
(Resin stability)
The time during which the rate of change in viscosity when the storage stability test was conducted in a 40 ° C. atmosphere was 150% was measured and evaluated according to the following criteria.

○: 30 days or more, ×: less than 30 days (content of β-ketoester group)
(1) In the case of polymerization of (meth) acrylate having an acetoacetoxy group (Examples 1 to 9 and Comparative Examples 1 and 2)
β-ketoester group content (mol / g) = [(Meth) acrylate charge mass (g) / (Meth) acrylate molecular weight] / total mass (g)
(2) When introducing a monomer that forms a β-ketoester group into a resin skeleton by alcohol exchange (Examples 10 to 12)
β-ketoester group content (mol / g) = [monomer charge mass (g) × conversion / monomer molecular weight] / [resin mass (g) + monomer charge mass (g ) X conversion rate-mass of dealcohol (g)]

表１に示した結果より、質量平均分子量が９２００〜４２０００のアクリル樹脂、ポリエステル樹脂又はアルキッド樹脂である実施例１〜１２においては、４０℃で３０日以上の期間に渡って粘度の大きな上昇がなく、樹脂安定性（貯蔵安定性）に優れていた。一方、質量平均分子量が６３０のオリゴマーである比較例２では、４０℃で３０日未満の期間で粘度上昇が極めて大きくなり、貯蔵安定性が悪いという結果であった。
（ウレタンアクリレートの合成）
攪拌機、温度計、コンデンサー及び窒素ガス導入管を備えた四ツ口フラスコにトルエン１２０部、キシリレンジイソシアネートのトリメチロールプロパンアダクト変性タイプ（三井タケダケミカル（株）製、Ｄ−１１０Ｎ）１００部、ポリカプロラクトン変性ヒドロキシエチルアクリレート（ダイセル化学工業（株）製、プラクセルＦＡ−１）７０部、ジブチル錫ジラウレート０．０２部及びハイドロキノンモノメチルエーテル０．２部を仕込んだ。そして、７０℃まで昇温し、液温をその温度に３時間保持することにより、固形分５０％のウレタンアクリレートを得た。
（実施例１３〜２６及び比較例３〜７）
次に、実施例１３〜２６では、上記のウレタンアクリレートに、実施例１〜１２で得られたアクリル樹脂、ポリエステル樹脂又はアルキッド樹脂を表２に示す含有量で混合し、活性エネルギー線重合開始能を有する重合性組成物を調製した。一方、比較例３〜７では、前記ウレタンアクリレートに、比較例１のアクリル樹脂１０、比較例２のオリゴマー、ＡＡＥＭ又は光重合開始剤（Irg.184）を表２に示す含有量で混合して組成物を調製した。なお、光重合開始剤（Irg.184）は、１−ヒドロキシシクロヘキシルフェニルケトンである。そして、各組成物について、下記に示す方法で硬化性、汚染性、臭気及び耐候性を評価し、それらの結果を表２に示した。
（硬化性）
高圧水銀灯を用い、８０Ｗ、距離３ｍ（積算光量３００ｍＪ／ｃｍ^２）の紫外線を照射したパス回数と指触乾燥性で次の基準にて評価した。

From the results shown in Table 1, in Examples 1 to 12 which are acrylic resin, polyester resin or alkyd resin having a mass average molecular weight of 9200 to 42000, the viscosity greatly increases over a period of 30 days or more at 40 ° C. There was no resin stability (storage stability). On the other hand, in Comparative Example 2 which is an oligomer having a mass average molecular weight of 630, the increase in viscosity was extremely large at a period of less than 30 days at 40 ° C., resulting in poor storage stability.
(Synthesis of urethane acrylate)
A four-necked flask equipped with a stirrer, thermometer, condenser and nitrogen gas inlet tube is 120 parts of toluene, 100 parts of xylylene diisocyanate trimethylolpropane adduct modified type (Mitsui Takeda Chemical Co., Ltd., D-110N), poly 70 parts of caprolactone-modified hydroxyethyl acrylate (manufactured by Daicel Chemical Industries, Plaxel FA-1), 0.02 part of dibutyltin dilaurate and 0.2 part of hydroquinone monomethyl ether were charged. And it heated up to 70 degreeC and hold | maintained the liquid temperature at the temperature for 3 hours, and obtained the urethane acrylate of 50% of solid content.
(Examples 13 to 26 and Comparative Examples 3 to 7)
Next, in Examples 13 to 26, the acrylic resin, polyester resin or alkyd resin obtained in Examples 1 to 12 was mixed with the above urethane acrylate at the contents shown in Table 2, and active energy ray polymerization initiation ability was mixed. A polymerizable composition having was prepared. On the other hand, in Comparative Examples 3 to 7, the urethane acrylate was mixed with the acrylic resin 10 of Comparative Example 1, the oligomer of Comparative Example 2, AAEM or a photopolymerization initiator (Irg. 184) in the contents shown in Table 2. A composition was prepared. The photopolymerization initiator (Irg. 184) is 1-hydroxycyclohexyl phenyl ketone. And about each composition, sclerosis | hardenability, pollution property, odor, and weather resistance were evaluated by the method shown below, and those results were shown in Table 2.
(Curable)
Using a high-pressure mercury lamp, the number of passes irradiated with ultraviolet rays of 80 W and a distance of 3 m (integrated light amount 300 mJ / cm ² ) and dryness to touch were evaluated according to the following criteria.

○: Within 2 pass times, □: 3 pass times, Δ: 4 pass times or more, ×: Not cured.
(Contamination)
Contamination property was evaluated by the number of passes in which dry touch was obtained. That is, the painted surface was drawn with a fluorescent pen. And after leaving it to stand at room temperature for one day, it was wiped off with ethanol, and the presence or absence of traces was visually evaluated according to the following evaluation criteria.

○: No trace, Δ: Some trace, x: Significant trace.
(Odor)
The odor of the film immediately after curing was subjected to sensory evaluation and evaluated according to the following criteria.

○: No odor at all, Δ: Slightly odorous, ×: Significant odor.
(Weatherability)
Using a sunshine weather meter, the change in color difference (ΔE) after the 1000 hour cycle test was measured and evaluated according to the following criteria.

  ◯: When ΔE is less than 1.0, Δ: When ΔE is 1.0 or more and less than 3.0, ×: When ΔE is 3.0 or more.

表２に示した結果より、実施例１３と比較例３との比較により、ＡＡＥＭが共重合されていない比較例３では光重合活性が得られず、ＡＡＥＭを共重合した実施例１３では十分な光重合活性が認められた。また、実施例１３と比較例４との比較から、比較例４に示すＡＡＥＭ（モノマー）をそのまま共重合させた場合には光重合活性が認められず、実施例１３に示すＡＡＥＭの高分子を共重合させた場合に光重合活性が得られた。さらに、実施例１５と１６とを比較すると、ＡＡＥＭの含有量の多い実施例１５の方が硬化性に優れていた。

From the results shown in Table 2, comparison between Example 13 and Comparative Example 3 revealed that no photopolymerization activity was obtained in Comparative Example 3 in which AAEM was not copolymerized, and sufficient in Example 13 in which AAEM was copolymerized. Photopolymerization activity was observed. Further, from the comparison between Example 13 and Comparative Example 4, when the AAEM (monomer) shown in Comparative Example 4 was copolymerized as it was, no photopolymerization activity was observed, and the AAEM polymer shown in Example 13 was not used. Photopolymerization activity was obtained when copolymerized. Further, when Examples 15 and 16 were compared, Example 15 having a higher AAEM content was superior in curability.

  When Example 13 was compared with Examples 15 and 19, Example 13 having a higher β-ketoester group content was superior to Examples 15 and 19 in curability. From a comparison between Example 13 and Comparative Example 5, in Comparative Example 5, since a normal photopolymerization initiator was used, the contamination, odor, and weather resistance were greatly reduced. Further, when Example 20 and Comparative Example 6 were compared, Example 20 using a polymer photopolymerization initiator was superior in curability to Comparative Example 6 using a normal photopolymerization initiator.

When Examples 14, 17 and 18 were compared, in Examples 14 and 18 in which the hydroxyl value was 10 mg KOH / g or less, no decrease in curability was observed, but in Example 17 exceeding 30 mg KOH / g, the curability was decreased. . When Example 14 is compared with Examples 24, 25, and 26, it is possible to introduce a β-ketoester group by an alcohol exchange reaction using an acrylic polyol, a polyester polyol, and an alkyd polyol. Compared with Example 14, the curability decreased.
(Examples 27 to 32 and Comparative Examples 8 and 9)
In Example 27, the acrylic resin 1 of Example 1 was used, and the acrylic resin 1 was coated and cured on the substrate in the same manner as in Example 13 to form an undercoat layer (film). Next, the urethane acrylate was coated on the obtained undercoat layer and cured to form an overcoat layer (film), and a two-layer film was provided on the substrate. In Examples 28 and 29, a two-layer coating was provided on the substrate in the same manner as in Example 27 except that instead of the acrylic resin 1 in Example 27, the acrylic resin 2 or the acrylic resin 4 was used. In Example 30, a photopolymerization initiator (Irg. 184) was further added in Example 27, and a two-layer coating was provided on the substrate in the same manner as in Example 27. In Example 31, as a composition for forming the undercoat layer in Example 27, 90 parts of acrylic resin 1 and 10 parts of urethane acrylate were mixed. In Example 31, the composition for forming the undercoat layer in Example 30 was 90 parts of acrylic resin 1 and 10 parts of urethane acrylate.

  On the other hand, in Comparative Example 8, the acrylic resin 10 was used instead of the acrylic resin 1 in Example 27, and in Comparative Example 9, the photopolymerization initiator (Irg. 184) was further added in Example 27, and the same as in Example 27. A two-layer coating was provided on the substrate.

And about each composition, sclerosis | hardenability of an overcoat layer, interlayer adhesiveness, contamination | pollution property, and an odor were evaluated by the method shown below, and those results were shown in Table 3. The interlayer adhesion was measured as follows.
(Interlayer adhesion)
Two layers of the coating on the substrate were cut into a grid pattern with an interval of 1 mm, a peel test with an adhesive tape was performed, and the following criteria were evaluated according to the number of remaining coatings.

  ○: 100/100, □: 99/100 to 50/100, Δ: 49/100 to 1/100, x: 0/100

表３に示した結果より、実施例２７、２８と実施例２９とを比較すると、アンダーコート層についてもβ−ケトエステル基の含有量が多い実施例２７、２８の方が硬化性などの物性に優れていた。実施例２７と比較例８とを比較すると、比較例８ではＡＡＥＭが共重合されていないアンダーコート層上に光重合開始剤を含まないオーバーコート層を形成し、紫外線を照射したため、オーバーコート層は硬化しなかった。実施例３１と３２とを比較すると、オーバーコート層に光重合開始剤が含まれている実施例３２では、その光重合開始剤により汚染性及び臭気が低下した。比較例９では、オーバーコート層に光重合開始剤を含有させたため、オーバーコート層は硬化したが、層間密着性などの物性について良好な結果が得られなかった。
（実施例３３及び３４）
実施例３３では、実施例１３において、ウレタンアクリレートに代えて、ＤＰＨＡ（ジペンタエリスリトールペンタ及びヘキサアクリレート、東亞合成（株）製、アロニックスＭ−４０２）を用い、その他は実施例１３と同様に実施した。実施例３４では、実施例１３において、ウレタンアクリレートに代えて、ＴＭＰＴＡ（トリメチロールプロパントリアクリレート、ダイセル・サイテック（株）製、ＴＭＰＴＡ）を用い、その他は実施例１３と同様に実施した。そして、各組成物について、硬化性、汚染性、臭気及び耐候性を評価し、それらの結果を表４に示した。

From the results shown in Table 3, when Examples 27 and 28 are compared with Example 29, Examples 27 and 28 having a higher β-ketoester group content in the undercoat layer also have physical properties such as curability. It was excellent. When Example 27 and Comparative Example 8 were compared, in Comparative Example 8, an overcoat layer containing no photopolymerization initiator was formed on the undercoat layer on which AAEM had not been copolymerized, and the overcoat layer was irradiated. Did not cure. When Examples 31 and 32 were compared, in Example 32 in which the photopolymerization initiator was contained in the overcoat layer, the contamination and odor were reduced by the photopolymerization initiator. In Comparative Example 9, since a photopolymerization initiator was contained in the overcoat layer, the overcoat layer was cured, but good results with respect to physical properties such as interlayer adhesion were not obtained.
(Examples 33 and 34)
In Example 33, DPHA (dipentaerythritol penta and hexaacrylate, manufactured by Toagosei Co., Ltd., Aronix M-402) was used instead of urethane acrylate in Example 13, and the others were carried out in the same manner as Example 13. did. In Example 34, TMPTA (trimethylolpropane triacrylate, manufactured by Daicel Cytec Co., Ltd., TMPTA) was used in place of urethane acrylate in Example 13, and the others were performed in the same manner as Example 13. Each composition was evaluated for curability, contamination, odor, and weather resistance. The results are shown in Table 4.

表４の実施例３３及び３４に示したように、ウレタンアクリレート以外の活性エネルギー線硬化性単量体を用いた結果、硬化性、汚染性、臭気及び耐候性のいずれについても前記ウレタンアクリレートの場合と同様の優れた結果が得られた。

As shown in Examples 33 and 34 of Table 4, as a result of using an active energy ray-curable monomer other than urethane acrylate, the case of urethane acrylate with respect to any of curability, contamination, odor and weather resistance Excellent results similar to those obtained were obtained.

It should be noted that the present embodiment can be modified as follows .

-When using the said polymerization initiator, it is also possible to use together polymerization accelerators, such as ethyl-4-dimethylaminobenzoate.
-When forming an overcoat layer on the said undercoat layer, it is also possible to mix | blend the said polymerization initiator with an overcoat layer.

  -It is also possible to irradiate an active energy ray-curable monomer with an active energy ray using the polymerization initiator, cure it into a film or a sheet, and use it as an optical functional member such as an optical lens.

Further, the technical idea that can be grasped from the embodiment will be described below.
The R in the chemical formula (1) represents a residue of a resin skeleton having a mass average molecular weight of 3,000 to 50,000. active energy Senkasane initiator. When comprised in this way, the effect of the invention which concerns on any one of Claims 1-4 can fully be exhibited.

- (meth) acrylates having an acetoacetoxy group, the active energy Senkasane initiator according to claim 3 or claim 4, characterized in that it is acetoacetoxyethyl (meth) acrylate. When comprised in this way, the effect of the invention which concerns on Claim 3 or Claim 4 can be exhibited effectively.

Claims (9)

An active energy ray polymerization initiator represented by the following chemical formula (1), wherein a β-ketoester group is bonded to an acrylic resin, a polyester resin, or an alkyd resin.

Here, R ^represents R 1 -O-, ^{R 1} represents a portion other than β- ketoester group of the acrylic resin, a polyester resin or alkyd resin. 2. The active energy ray polymerization initiator according to claim 1, wherein the content of the β-ketoester group is 2.0 × 10 ^{−4 to} 5.0 × 10 ⁻³ mol / g. The active energy ray polymerization initiator according to claim 1 or 2, wherein the β-ketoester group is introduced by polymerization of a (meth) acrylate having an acetoacetoxy group. 4. The active energy ray according to claim 1, wherein a portion other than the β-ketoester group of the acrylic resin, polyester resin, or alkyd resin does not have a hydroxyl group. 5. Polymerization initiator. An active energy ray comprising only the active energy ray polymerization initiator according to any one of claims 1 to 4 as a polymerization initiator and a monomer having active energy ray curability. A polymerizable composition having a polymerization initiating ability. 6. The polymerizable composition having active energy ray polymerization initiating ability according to claim 5, wherein the monomer having active energy ray curability is a compound having a (meth) acryloyl group. A polymerizable composition having an active energy ray polymerization initiating ability according to claim 5 or claim 6 is coated on a base material and irradiated with an active energy ray to be cured to form a film. Cured product. Other than the polymerizable composition having active energy ray polymerization initiating ability containing only the active energy ray polymerization initiator according to claim 5 or 6 and a monomer having active energy ray curability on the coating film. The cured product according to claim 7, wherein an overcoat layer is formed by applying the active energy ray-curable composition, and irradiating and curing the active energy ray. The cured product according to claim 8, wherein the active energy ray-curable composition contains a photopolymerization initiator.