JPH06136078A - Actinic energy ray-curing resin composition - Google Patents

Abstract

PURPOSE:To obtain an active energy ray-curing resin composition useful as a hard coating agent capable of giving coating films excellent in surface curability, scratch resistance and surface smoothness, by incorporating a polyfunctional urethane acrylate mixture with a special polyfunctional urethane acrylate. CONSTITUTION:The resin composition can be obtained by incorporating (A) 100 pts.wt. of a composition comprising (1) 40-60wt.% of a compound of formula I (n is 3-5; R<1> is 5-10C alcohol residue; R<2> is H or methyl; R<3> is organic diisocyanate residue; X is urethane bond) and (2) 60-40wt.% of a compound of formula II (n is 3-6) with (B) 0.1-10 pts.wt. of a polyfunctional urethane acrylate prepared by reaction of (3) a NCO-terminated prepolymer formed by reaction between (a) 1mol of a polydimethylsiloxanediol of formula III (n is 10-25; m1 and m2 are each 0-5) as polyol component and (b) 2mol of an organic diisocyanate of formula IV (R is 1-10C alkylene, phenylene, etc.) with (4) a compound of formula V (R<1> is OH-contg. 5-10C alcohol residue).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active energy ray-curable resin composition, particularly a composition usable as a harcoat material for imparting surface curability, scratch resistance, surface smoothness, etc. to plastics and the like. Regarding things.

[0002]

2. Description of the Related Art In recent years, plastic materials have been widely used as substitute materials for metal materials and the like, taking advantage of their toughness and workability, including engineering plastics. However, a surface protective layer is often provided due to lack of surface hardness and scratch resistance.

Conventionally, as a technique for hardening the surface of a plastic, a method of coating a thermosetting resin such as an organosiloxane type or a melamine type, a method of forming a metal thin film by a vacuum deposition method or a sputtering method, or a polyfunctional acrylate. Coating of systems with active energy ray curable resins has been carried out.

[0004]

However, in the case of surface protection using a conventional thermosetting resin, there is a drawback that productivity is low, and in the case of surface protection using a metal thin film,
Since the processing is performed in a vacuum system, the productivity is low, and processing of a large area is difficult. In addition, in the case of curing with active energy rays, although the productivity is good, the coating film tends to crack, peel, warp, etc. due to curing shrinkage during polymerization. In order to prevent the cracking of the cured coating film, attempts have been made to improve it by lowering the functional group concentration of the polyfunctional acrylate compound, which is the main component of the coating solution, or increasing the molecular weight. However, it was very difficult to obtain a good hard coat coating due to adverse effects such as a decrease in hardness and scratch resistance of the cured product.

Further, in the case of curing with active energy rays, since the coating film is a thin film having a thickness of about 5 μm, the polymerization is inhibited by oxygen during the polymerization, and the curability, abrasion resistance, surface smoothness and the like of the coating film are impaired. There was a tendency. As a method for preventing polymerization inhibition due to oxygen and maintaining curability, wear resistance, and surface smoothness, a method of adding paraffins to the coating liquid to prevent diffusion of oxygen into the coating liquid, or a coating liquid A method has been used to prevent the diffusion of oxygen by shielding the surface of the product with a transparent plastic film or the like. Furthermore, a method of irradiating active energy rays in an atmosphere of an inert gas such as nitrogen gas has been adopted.

However, these methods are not suitable in terms of product cost and mass productivity, and there are many problems when considered on an industrial scale. As a method for improving the wear resistance and surface smoothness of a cured coating film, various modifications of polydimethylsiloxane-based silicone oils such as epoxy modification, alkyd modification, amino modification, carboxyl modification, alcohol modification, etc. have been conventionally performed. By adding treated silicone oil, attempts have been made to improve scratch resistance and surface smoothness, which are the characteristics of the surface of the cured coating film, by utilizing the phenomenon of migration to the coating film surface during curing. .

However, since these various silicone-based additives do not have an active energy ray-curable functional group in the molecular bone or at the molecular end, they cannot be copolymerized with a polyfunctional acrylate. However, as a result, there are problems such as insufficient scratch resistance and surface smoothness, and hard coat agents excellent in curability, scratch resistance, and surface smoothness have not yet been obtained.

[0008]

[Means for Solving the Problems] As a result of intensive studies to solve the above-mentioned problems, as a result, a polyfunctional urethane acrylate mixture synthesized from an organic diisocyanate and a polyfunctional acrylate, scratch resistance and surface smoothness in the main chain were obtained. Introducing a polydimethylsiloxane skeleton and an isocyanurate skeleton, which have excellent properties, and a mixture of urethane acrylate with a plurality of acryloyl groups or methacryloyl groups with high active energy ray curability introduced at the molecular ends, curability, scratch resistance, Inventing an active energy ray-curable resin composition having excellent surface smoothness, when used, it is possible to obtain a hard coat material excellent in curability by active energy rays, scratch resistance, and surface smoothness. I found what I could do.

That is, the present invention provides "the following general formula (I) << In the formula, n represents an integer of 3 to 5, and R ¹ has 5 to 5 carbon atoms.
10 is an alcohol residue, R ² is a hydrogen atom or a methyl group, R ³ is an organic diisocyanate residue,
X represents a urethane bond >> A compound 40 to 60
% By weight and the following general formula (II) [Wherein R ¹ is an alcohol residue having 5 to 10 carbon atoms, R ² is a hydrogen atom or a methyl group, and n represents an integer of 3 to 6] and a compound represented by 60 to 40 wt% 100 parts by weight of a composition consisting of << In the formula, n is an integer of 10 to 25, m1 and m2 represent 0 or an integer of 1 to 5, and 1 mol of polydimethylsiloxanediol represented by the following general formula: << In the formula, R represents an alkylene group having 1 to 10 carbon atoms, a phenylene group, or a substituted phenylene group >> formula << In the formula, R ¹ is an alcohol residue having 5 to 10 carbon atoms having at least one hydroxyl group, R ² is a hydrogen atom or a methyl group, and n is an integer of 3 to 5 It is an active energy ray-curable resin composition comprising 0.1 to 10 parts by weight of a polyfunctional urethane acrylate, which is obtained by reacting a compound.

The active energy ray-curable resin composition of the present invention comprises 40 to 60% by weight of the polyfunctional urethane acrylate represented by the general formula (I) and the polyfunctional urethane acrylate 60 represented by the general formula (II). 1 mol of the polydimethylsiloxane diol represented by the general formula (III) as a polyol component and 100 parts by weight of a polyisocyanate component with respect to 100 parts by weight of a composition consisting of
It is obtained by reacting a compound represented by the general formula (V) with an isocyanate group-terminated prepolymer obtained by reaction with 2 mol of the organic isocyanate represented by the general formula (IV).

When the active energy ray-curable composition of the present invention is used, a strong cured coating film having good curability with respect to active energy rays, abrasion resistance and surface smoothness can be obtained. . The mixture of the compounds represented by the general formulas (I) and (II) can be produced by the following reaction steps.

That is, it can be obtained by charging an excessive amount of a compound having a hydroxyl group and an acryloyl group or a methacryloyl group in the molecule with respect to 1 mol of an organic diisocyanate, in excess of the theoretical amount. The mixing ratio of the compounds represented by the general formulas (I) and (II) is most preferably in the range of 40 to 60% by weight of the compound represented by the general formula (I) with respect to the total weight of both. If it is less than 40% by weight, the flexibility of the cured product is insufficient, and if it exceeds 60% by weight, the surface hardness of the cured product is insufficient, which is not preferable as a hard coat material.

Specific examples of the compound having a hydroxyl group and an acryloyl group or a methacryloyl group in the molecule represented by the general formula (II) used in this reaction include pentaerythritol triacrylate, pentaerythritol trimethacrylate and dipentaerythritol. Examples thereof include triacrylate, dipentaerythritol trimethacrylate, dipentaerythritol tetraacrylate, dipentaerythritol tetramethacrylate, dipentaerythritol pentataacrylate and dipentaerythritol pentamethacrylate.

This reaction is carried out in a dry air atmosphere at 50-8.
It is performed in the temperature range of 0 ° C. Moreover, it is preferable to use a catalyst for this reaction. Examples of the catalyst include organic titanium compounds such as tetrabutyl titanate, tetrapropyl titanate and tetraethyl titanate, organic tin compounds such as tin octylate, dibutyltin oxide and cibutyltin dilaurate, and further stannous chloride and stannous bromide. , Stannous iodide and the like can be used. The addition amount of these catalysts is 10 to 10,000 PPM with respect to the total charged amount.

Further, a radical polymerization inhibitor may be used for suppressing radical polymerization of the acryloyl group. Radical polymerization inhibitors include hydroquinone monomethyl ether, d-t-butyl hydroquinone, P-
Examples thereof include t-butylcatechol and phenothiazine. The addition amount is 10 to 10,000 with respect to the total amount charged.
ppm is a proper amount. Since the reaction yield of the urethane acrylate mixture obtained by this reaction is almost 100%,
No special production process is required.

Examples of the organic diisocyanate used in the present invention include m-phenylene diisocyanate, p-phenylene diisocyanate, 1-chloro-2,4-phenylene diisocyanate, 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate. , 1,5-naphthylene diisocyanate, diphenylmethane-4,
4'-diisocyanate, 3,3'-dimethyl-4,
Aromatic diisocyanates such as 4'-buphenylene diisocyanate, ethane diisocyanate, propane diisocyanate, butane diisocyanate, pentane diisocyanate, hexane diisocyanate, heptane diisoanate, octane diisoanate, nonane diisocyanate, decane diisocyanate, dicyclohexylmethane diisocyanate And aliphatic diisocyanates such as isophorone diisocyanate.

A urethane acrylate having a polydimethylsiloxane skeleton and an isocyanurate skeleton in the main chain can be produced by the following two-step reaction process. First
The reaction in the second stage is a step of obtaining a urethane prepolymer having 2 mol of isocyanate groups at the molecular ends by reacting 1 mol of polydimethylsiloxane diol having a hydroxyl group at the molecular ends with 2 mol of polyisocyanate having an isocyanurate skeleton.

This reaction is generally represented by the following reaction formula << However, Rx represents a residue of the polydimethylsiloxane diol represented by the general formula (III), and R represents a carbon number of 1 to 1.
R 10 represents an alkyl group, a phenylene group or a substituted phenylene group, and R ^(IV) is a residue excluding all RNCO groups in the compound represented by the general formula (IV).

Specific examples of the compound represented by the general formula (IV) used in this reaction include hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate,
Examples include trimers of 4,4′-methylenebis (cyclohexyldiisocyanate), isophorone diisocyanate, and trimethylhexamethylenediisocyanate. The isocyanate-terminated urethane prepolymer obtained at this stage has extremely poor solubility in organic solvents and cannot be dissolved in many organic solvents which are usually used industrially. However, some ketones,
In particular, it has extremely good solubility in acetone. Therefore, after the polyisocyanate having the isocyanurate skeleton is previously dissolved in acetone during the reaction,
The reaction is a condition for obtaining a urethane acrylate solution having a uniform composition.

This reaction is carried out at room temperature to 50 ° C. under a nitrogen atmosphere.
Perform within the temperature range. This reaction preferably uses a catalyst. Examples of the catalyst include organic titanium compounds such as tetrabutyl titanate, tetrapropyl titanate and tetraethyl titanate, organic tin compounds such as tin octylate, dibutyltin oxide and cibutyltin dilaurate, and further stannous chloride and stannous bromide. , Stannous iodide and the like can be used. The addition amount of these catalysts is 10 to 10,000 PPM with respect to the total charged amount.

The reaction of adding an acrylate compound having a hydroxyl group at the molecular end and an acryloyl group which is a radically polymerizable unsaturated group to 1 mol of the urethane acrylate prepolymer having isocyanate groups at both ends of the molecule thus produced is , In general,

However, Rx represents a residue of the polydimethylsiloxane diol represented by the general formula (III), and Rx
Represents an alkyl group having 1 to 10 carbon atoms, a phenylene group, a substituted phenylene group, R ^(IV) is a residue excluding the three RNCO groups in the compound represented by the general formula (IV),
R ³ is a residue of the compound represented by formula (V). This reaction is basically the same urethanization reaction as in the step of obtaining a urethane prepolymer.

The amount of the acrylate compound having a hydroxyl group at the terminal of the molecule and an acryloyl group which is a radically polymerizable unsaturated group is an excessive amount with respect to 1 mol of the urethane acrylate prepolymer having an isocyanate group at both terminals of the molecule. It is preferable to use 5 to 7 mol. The reason for this is that the isocyanate groups remaining in the urethane prepolymer have extremely poor reactivity with hydroxyl groups and the urethane formation reaction does not proceed unless the reaction is performed under an excessive concentration of hydroxyl groups. This addition reaction is performed in a temperature range of room temperature to 50 ° C. in a dry air atmosphere.
A catalyst is preferably used for this reaction. The catalyst, tetrabutyl titanate, tetrapropyl titanate, organic titanium compounds such as tetraethyl titanate, tin octylate, dibutyl tin oxide, organotin compounds such as cibutyltin dilaurate, further stannous chloride,
Stannous bromide, stannous iodide and the like can be used.

The amount of this catalyst used is 1 with respect to the total amount charged.
It is 0 to 10,000 PPM. Further, a radical polymerization inhibitor may be used to suppress radical polymerization of the acryloyl group. Examples of the radical polymerization inhibitor include hydroquinone monomethyl ether, d-t-butyl hydroquinone, p-t-butyl catechol, phenothiazine and the like. The addition amount is 10 with respect to the total amount charged.
A suitable amount is ˜10,000 ppm. The urethane acrylate obtained by this reaction has a reaction yield of almost 100%, and thus does not require a special production step.

When the polyfunctional urethane acrylate having a polydimethylsiloxane skeleton and an isocyanurate skeleton in the main chain thus obtained is mixed with another polyfunctional acrylate compound to prepare a photocurable resin composition, Since it is easily copolymerized with other polyfunctional acrylates, it serves as a constituent of the cured film and has the effect of improving the abrasion resistance of the coating film. Further, since the migration phenomenon from the cured film is suppressed, it can contribute to the improvement of the surface smoothness of the cured film, unlike the silicone additives which are usually used. The polyfunctional urethane acrylate obtained in the present invention has a polydimethylsiloxane skeleton in the main chain and at the same time has an isocyanurate skeleton, so that it is possible to impart surface smoothness and scratch resistance to the urethane acrylate.

Further, since a plurality of highly curable acryloyl groups and methacryloyl groups are present at the molecular terminals, good curability with respect to active energy rays can be provided. The polydimethylsiloxane diol used in the present invention has n of 10 to 25 in the composition represented by the general formula (II).
Is most preferable. When n is less than 10, the characteristics of the polydimethylsiloxane skeleton such as scratch resistance and surface smoothness do not appear, and when n exceeds 25, a sufficient crosslink density cannot be obtained, which is not preferable.

The active energy ray-curable resin composition of the present invention is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the compound represented by the general formula (I). If it is less than 0.1 parts by weight, the effect as an additive does not appear, and if it exceeds 10 parts by weight, the surface smoothness of the effect product is adversely affected.

When the ultraviolet-curable resin composition of the present invention is irradiated with ultraviolet rays to be photo-cured, a photopolymerization initiator can be used, but it is particularly preferable as long as it initiates and accelerates the polymerization reaction of the acryloyl group. There is no limitation, and known compounds can be used. Specifically as a photopolymerization initiator,
2,2-hydroxy-2-phenylacetophenone, acetophenone, benzophenone, xanthone, fluorenone, benzaldehyde, anthraquinone, triphenylamine, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone,
N, N, N ', N'-tetramethyl-4,4'-diaminobenzophenone, benzoinpropyl ether, acetophenone diethyl ketal, benzoin ethyl ether, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy- 2-methylpropane
Examples include 1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one and other thioxanthone compounds, and one or more of these compounds can be used.

The amount of the photopolymerization initiator used is preferably 0.1 to 15 parts by weight, more preferably 1 to 5 parts by weight, based on the photocurable resin composition of the present invention.

Examples> The present invention will be described below with reference to Examples. Synthesis Example 1 (Synthesis Example of Polyfunctional Urethane Acrylate) 3 L equipped with a gas introduction pipe, a thermometer, a cooling pipe and a stirring device
Isophorone diisocyanate 444 in a 4-necked flask
Parts and 2.828 parts of dibutyltin dilaurate as a catalyst and 1.41 parts of hydroquinone monomethyl ether as a polymerization inhibitor were charged and kept at a temperature of 60 ° C. in a dry air atmosphere. Then, 2,384 parts of pentaerythritol triacrylate was gradually added dropwise to carry out the reaction, and the reaction was continued until the absorption peak due to the isocyanate group at 2,330 cm-1 disappeared from the infrared absorption spectrum, and the polyfunctional urethane acrylate and the polyfunctional urethane acrylate were added. A mixture of acrylic compounds (oligomer A) was obtained.

Synthesis Examples 2 to 4 (same as above) Instead of isophorone diisocyanate as the organic diisocyanate, 264 parts of hexamethylene diisocyanate and 383 parts of 2,4 tolylene diisocyanate, respectively.
Synthesis was performed in the same manner as in Synthesis Example 1 except that 524 parts of dicyclohexylmethane diisocyanate was used to obtain oligomers B, C and D thereof. Synthesis Example 5 (Synthesis Example of Polydimethylsiloxane-Containing Urethane Acrylate) Isophorone diisocyanate trimer was added to a 3 L four-necked flask equipped with a gas inlet tube, a thermometer, a cooling tube, and a stirrer (T-1890; (Huls trade name) 320 parts and 1.332 parts of dibutyltin dilaurate as a catalyst were dissolved in 1,332 parts of acetone and the temperature was kept at 40 ° C.

Next, the average composition formula is In a nitrogen atmosphere, 430 parts of polydimethylsiloxane having a molecular end blocked with a hydroxyl group is
Isocyanate concentration is 5.37%
A urethane prepolymer of was obtained.

Next, at the same reaction temperature, 0.666 part of hadroquinone-n-methyl ether as a polymerization inhibitor was added, and 1,332 parts of pentaerythritol triacrylate were gradually added dropwise by a dropping funnel over 3 hours under dry air. did. After completion of the dropping, the reaction is further continued, and the reaction is continued until the absorption peak due to the isocyanate group at 2,330 cm ⁻¹ disappears according to the infrared absorption spectrum, and a polyfunctional compound having a polydimethylsiloxane skeleton and an isocyanurate skeleton in the main chain. An acetone solution (oligomer E) of urethane acrylate and a polyfunctional acrylic compound was obtained.

Synthesis Example 6 The average composition is Acetone solution of a polyfunctional urethane acrylate having a polydimethylsiloxane skeleton and an isocyanurate skeleton in its main chain and a polyfunctional acrylic compound (in the same manner as in Synthesis Example 1 except that 240 parts of polydimethylsiloxane represented by Oligomer F) was obtained.

Synthesis Example 7 The average composition is Acetone solution of a polyfunctional urethane acrylate having a polydimethylsiloxane skeleton and an isocyanurate skeleton in its main chain and a polyfunctional acrylic compound (in the same manner as in Synthesis Example 1 except that 550 parts of polydimethylsiloxane represented by Oligomer G) was obtained.

Using the oligomers obtained in Synthesis Examples 1 to 7 and having the compositions shown in Table 1, surface curability and scratch resistance of cured products,
The surface smoothness was evaluated by the following method. (1) Surface curability The presence or absence of tack on the surface of the obtained cured product is judged by touching with a finger. ○ ・ ・ ・ ・ With tack × ・ ・ ・ ・ Without tack

(2) Scratch resistance The cured surface is scratched with steel wool # 0000 and judged by the degree of scratching. ○: almost no scratch △: slightly scratched ×: markedly scratched (3) Surface smoothness The obtained cured surface is observed and judged. ○ ・ ・ ・ ・ Good × ・ ・ ・ ・ Slightly disturbed

Examples 1 to 8 and Comparative Examples 1 to 4 Photocurable resin compositions shown in Table 1 were prepared. The evaluation sample is polyethylene terephthalate (S-25 Teijin Ltd.)
A high pressure mercury lamp (lamp input 120W /
cm) at a conveyor speed of 30 m / min. What was hardened by irradiating an ultraviolet ray once was used. As a photopolymerization initiator, Irgacure 500 (trade name of Ciba Geigy) was used.

The evaluation results are shown in Table 1.

[0040]

[0041]

The active energy ray-curable resin composition of the present invention has excellent surface curability, scratch resistance and surface curability. When it is added to other polyfunctional acrylic compounds, etc., it has excellent scratch resistance. A coating is obtained.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C09D 4/02 PEA 7921-4J

Claims (1)

[Claims] 1. The following general formula (I): << In the formula, n represents an integer of 3 to 5, and R ¹ has 5 to 5 carbon atoms.
10 is an alcohol residue, R ² is a hydrogen atom or a methyl group, R ³ is an organic diisocyanate residue,
X represents a urethane bond >> A compound 40 to 60
% By weight and the following general formula (II) [Wherein R ¹ is an alcohol residue having 5 to 10 carbon atoms, R ² is a hydrogen atom or a methyl group, and n represents an integer of 3 to 6] and a compound represented by 60 to 40 wt% 100 parts by weight of a composition consisting of << In the formula, n is an integer of 10 to 25, m1 and m2 represent 0 or an integer of 1 to 5, and 1 mol of polydimethylsiloxanediol represented by the following general formula: << In the formula, R represents an alkylene group having 1 to 10 carbon atoms, a phenylene group, or a substituted phenylene group >> formula << In the formula, R ¹ is an alcohol residue having 5 to 10 carbon atoms having at least one hydroxyl group, R ² is a hydrogen atom or a methyl group, and n is an integer of 3 to 5 An active energy ray curable resin composition comprising 0.1 to 10 parts by weight of a polyfunctional urethane acrylate obtained by reacting a compound.