JP3193495B2 - Active energy ray-curable resin composition - Google Patents

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, and more particularly to a hard coat material used for imparting surface curability, scratch resistance, surface smoothness and the like to plastics and the like. Composition.

[0002]

2. Description of the Related Art In recent years, plastic materials, such as engineering plastics, have been widely used as substitute materials for metal materials and the like, taking advantage of their features such as toughness and workability. However, a surface protective layer is often provided due to lack of surface hardness and scratch resistance. Conventionally, techniques for hardening plastic surfaces include methods of coating a thermosetting resin such as organosiloxane or melamine, forming a metal thin film by vacuum evaporation or sputtering, or the activity of polyfunctional acrylates. Coating with energy ray-curable resins has been performed.

However, in the case of the conventional surface protection using a thermosetting resin, there is a disadvantage that the productivity is low. In the case of the surface protection using a metal thin film, the productivity is low due to processing in a vacuum system, and the area is large. There is a drawback that the processing of is difficult. In the case of active energy ray curing, the thickness of the coating film is about 5 μm, and therefore, the polymerization tends to be inhibited by oxygen during polymerization, and the curability, abrasion resistance, surface smoothness, etc. of the coating film tend to be impaired. Was.

As a method of preventing polymerization inhibition by oxygen and maintaining curability, abrasion resistance, and surface smoothness, a method of adding paraffins to a coating solution to prevent diffusion of oxygen into the coating solution, In addition, a method of shielding the surface of a coating solution with a transparent plastic film or the like to prevent diffusion of oxygen has been adopted. Further, a method of irradiating an active energy ray under an atmosphere of an inert gas such as a nitrogen gas has been adopted.

[Problems to be solved by the invention]

However, these methods are not appropriate in terms of product cost and mass productivity, and have many problems when considered on an industrial scale. As a method for improving the abrasion resistance and surface smoothness of a cured coating film, conventionally, various modifications of a polydimethylsiloxane-based silicone oil, for example, epoxy modification, alkyd modification, amino modification, carboxyl modification, alcohol modification, etc. Attempts have been made to add the treated silicone oil to improve the 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, these various silicone-based additives have no active energy ray-curable functional groups in the molecular skeleton or at the molecular terminals, and therefore cannot be copolymerized with polyfunctional acrylates. As a result, there are problems such as insufficient scratch resistance and surface smoothness, and a hard coat agent excellent in curability, scratch resistance and surface smoothness has not yet been obtained.

[0007]

As a result of intensive studies to solve the above-mentioned problems, a polydimethylsiloxane skeleton having excellent scratch resistance and surface smoothness was introduced into the main chain at the same time as an isocyanurate skeleton was introduced into the main chain. Active energy ray-curable resin composition with excellent curability, scratch resistance, and surface smoothness by introducing a plurality of acryloyl groups or methacryloyl groups with high active energy ray-curable properties at the terminals and further using together with a polyfunctional acrylate. It has been found that a hard coat material excellent in curability by active energy rays, scratch resistance and surface smoothness can be obtained.

[0008]

Means for Solving the Problems The present invention relates to (a) the following general formula (I) <Wherein, R ¹ is an alcohol residue having 5 to 10 carbon atoms, R ² is H or CH ₃ , and n represents an integer of 3 to 6 >
100 parts by weight of a compound represented by the formula (b): 0.1 to 12.5 parts by weight of a polyfunctional urethane acrylate [However, (b) is a polyol component and is represented by the following general formula (II): << In the formula, n is an integer of 10 to 25, and m1 and m2 are 0
Or an integer of 1 to 5, R represents a methyl group or a hydrogen atom >> and 1 mol of polydimethylsiloxanediol represented by the following general formula as a polyisocyanate component: In the formula, R represents an alkylene group having 1 to 10 carbon atoms, a phenylene group, or a substituted phenylene group. The prepolymer at the terminal of the isocyanate group obtained by reaction with 2 mol of the organic isocyanate represented by the formula: , The following general formula Wherein R ¹ is an alcohol residue having at least one hydroxyl group and having 5 to 10 carbon atoms, and R ² is H or CH ₃
And n represents an integer of 3 to 5>. The active energy ray-curable resin composition "is characterized by the following formula:

The following general formula (I), which is one of the starting materials (a) in the active energy ray-curable resin composition of the present invention: Specific compounds represented by are pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol triacrylate, dipentaerythritol trimethacrylate, dipentaerythritol tetraacrylate, dipenta Erythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate,
Examples include dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, trimethylolpropane triacrylate, and trimethylolpropane trimethacrylate.

The component (b), which is another starting material in the active energy ray-curable resin composition of the present invention, is synthesized by the following reaction procedure. That is, the following general formula (II) In the formula, n is an integer of 10 to 25, m1 and m2 represent 0 or an integer of 1 to 5, and R represents a methyl group or a hydrogen atom. Formula (III) <Wherein, R represents an alkylene group having 1 to 10 carbon atoms, a phenylene group, or a substituted phenylene group> First, an isocyanate group-terminated prepolymer obtained by reaction with 2 mol of an organic isocyanate represented by the following formula: I do.

Next, the isocyanate group of the isocyanate group-terminated prepolymer is represented by the following general formula (IV): Wherein R ¹ is an alcohol residue having at least one hydroxyl group and having 5 to 10 carbon atoms, and R ² is H or CH ₃
And n represents an integer of 3 to 5 >> to obtain a polyfunctional urethane acrylate.

[0012] Are the following compounds: hexamethylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, 4,4'-methylene bis (cyclohexyl isocyanate), isophorone diisocyanate,
It is a trimer of trimethylhexamethylene diisocyanate.

Further, Specific examples of the compound include pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol triacrylate, dipentaerythritol trimethacrylate, dipentaerythritol tetraacrylate, dipentaerythritol tetramethacrylate, dipentaerythritol pentamethacrylate, and the like. .

In the polydimethylsiloxane diol represented by the above general formula (II), when n is less than 10, the cured film obtained by curing the curable resin composition has a polydimethylsiloxane having scratch resistance and surface smoothness. When the characteristics of the skeleton do not appear and n exceeds 25, a sufficient crosslinking density cannot be obtained, which is not preferable.

[0015] In the active energy ray curable resin composition of the invention, (a) the general formula (I) 0.1 to the (b) component with respect to 100 parts by weight of the compound represented by 12 is a component. It is essential to blend 5 parts by weight. When the amount is less than 0.1 part by weight, the effect as an additive does not appear, and when it exceeds 12.5 parts by weight, the surface smoothness of the cured product is adversely affected.

A urethane acrylate having a polydimethylsiloxane skeleton and an isocyanurate skeleton in the main chain can be produced by the following two-step reaction steps. << However, R ^X represents a residue of the polydimethylsiloxane diol represented by the general formula (II), R ¹ represents a methyl group or a hydrogen atom, and R ² represents an alkylene group having 1 to 10 carbon atoms, a phenylene group. Represents a substituted phenylene group >>.

In the first reaction, a urethane prepolymer having 2 mol of isocyanate groups at the molecular terminals is obtained by reacting 1 mol of polydimethylsiloxane diol having a hydroxyl group at the molecular terminals with 2 mol of a polyisocyanate having an isocyanurate skeleton. It is a process.

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, it shows very good solubility for some ketones, especially acetone. Therefore, it is a condition for obtaining a urethane acrylate solution having a uniform composition by dissolving the polyisocyanate having an isocyanurate skeleton in acetone in advance during the reaction and then reacting.

This reaction is carried out at room temperature to 50 ° C. in a nitrogen atmosphere.
The temperature range is as follows. This reaction preferably uses a catalyst. Examples of the catalyst include organic titanium compounds such as tetrabutyl titanate, tetrapropyl titanate, and tetraethyl titanate; organotin compounds such as tin octylate, dibutyltin oxide, and sibutyltin dilaurate; and stannous chloride and stannous bromide. And stannous iodide can be used. The addition amount of these catalysts is 10 to 10,000 PPM based on the total charged amount.

The reaction of adding an acrylate compound having a hydroxyl group at the molecular terminal and having an acryloyl group which is a radically polymerizable unsaturated group to 1 mol of a urethane acrylate prepolymer having isocyanate groups at both ends of the molecule thus produced is carried out. Can be generally represented by the following reaction formula. Next, 1 mol of the urethane prepolymer represented by the above general formula (V) is added to the above general formula (V). (B) by reacting 4 moles of the compound represented by
A polyfunctional urethane acrylate as a component is obtained.

[0021] << However, R ^X is a polydimethylsiloxane diol residue, R is an alkylene group having 1 to 10 carbon atoms, a phenylene group, a substituted phenylene group, and R is a residue of a compound represented by the general formula (IV) >>

This reaction is basically a urethanization reaction similar to the step of obtaining a urethane prepolymer. The charged amount of the acrylate compound having a hydroxyl group at the molecular terminal and having an acryloyl group which is a radical polymerizable unsaturated group is an excess amount of 5 to 7 with respect to 1 mol of a urethane acrylate prepolymer having an isocyanate group at both molecular terminals. It is preferable to use a mole.

The reason for this is that the isocyanate groups remaining in the urethane prepolymer have extremely poor reactivity with hydroxyl groups, and the urethane-forming reaction does not proceed unless the reaction is carried out under an excessive amount of hydroxyl groups. This addition reaction,
The reaction is carried out at room temperature to 50 ° C. in a dry air atmosphere. 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; organotin compounds such as tin octylate, dibutyltin oxide, and sibutyltin dilaurate; and stannous chloride and stannous bromide. And stannous iodide can be used. The amount of the catalyst used is 10 to 1 with respect to the total charge.
0000 PPM.

A radical polymerization inhibitor can be used to suppress the radical polymerization of the acryloyl group. Examples of the radical polymerization inhibitor include hydroquinone monomethyl ether, dt-butyl hydroquinone, p-
t-butylcatechol, phenothiazine and the like. The addition amount is 10 to 10,000 based on the whole charged amount.
ppm is an appropriate amount. Since the reaction yield of the urethane acrylate obtained in this reaction is almost 100%, no special purification step is required.

The polyfunctional urethane acrylate having a polydimethylsiloxane skeleton and an isocyanurate skeleton in the main chain obtained as described above is mixed with another polyfunctional acrylate compound to form a photocurable resin composition. Easily copolymerizes with the polyfunctional acrylate of the formula (1) and becomes a constituent of the cured film, which has the effect of improving the abrasion resistance of the coating film.
Further, since the migration phenomenon from the inside of the cured film is suppressed, unlike the silicone-based additive which is usually used, it can also contribute to the improvement of the surface smoothness of the cured film.

In the case where the ultraviolet-curable resin composition of the present invention is photocured by irradiating it with ultraviolet rays, a photopolymerization initiator can be used, but any photopolymerization initiator that initiates and accelerates the polymerization reaction of acryloyl groups can be used. 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, benzoin propyl ether, acetophenone diethyl ketal, benzoin ethyl ether, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy- 2-methylpropane-
Examples thereof 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 use amount of the photopolymerization initiator 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.

Hereinafter, the present invention will be described with reference to examples. Synthesis Example 1 3 L equipped with a gas inlet tube, a thermometer, a cooling tube, and a stirring device
Of isophorone diisocyanate in a four-necked flask
1.332 parts of a monomer (T-1890; trade name, manufactured by Huls Co.) and 1.332 parts of dibutyltin dilaurate as a catalyst were dissolved in 1.332 parts of acetone, and the temperature was maintained at 40 ° C.

Next, the average composition formula is In a nitrogen atmosphere, 470 parts of polydimethylsiloxane having a molecular end blocked by a hydroxyl group represented by
Drops slowly over time and isocyanate concentration 5.10%
Was obtained.

Then, at the same reaction temperature, 0.666 parts of haodoroquinone-n-methyl ether as a polymerization inhibitor was added, and 1,332 parts of pentaerythritol triacrylate was gradually added dropwise in a dropping funnel over 3 hours under dry air. did. After completion of the dropwise addition, the reaction was further continued until the absorption peak at 2,330 cm -1 due to the isocyanate group disappeared by infrared absorption spectrum, and a polyfunctional having a polydimethylsiloxane skeleton and an isocyanurate skeleton in the main chain. 2,660 parts (oligomer A) of an acetone solution of urethane acrylate and a polyfunctional acrylic compound were obtained.

Synthesis Example 2 Acetone solution 2 of a polyfunctional urethane acrylate having a polydimethylsiloxane skeleton and an isocyanurate skeleton in the main chain thereof in the same manner as in Synthesis Example 1 except that 240 parts of polydimethylsiloxane represented by .470 parts (oligomer B).

Synthesis Example 3 Acetone solution 2 of a polyfunctional urethane acrylate having a polydimethylsiloxane skeleton and an isocyanurate skeleton in the main chain thereof in the same manner as in Synthesis Example 1 except that 550 parts of the polydimethylsiloxane represented by 780 parts (oligomer C).

Using the oligomers obtained in Synthesis Examples 1 to 3, the cured product had the composition shown in Table 1 and had surface curability, scratch resistance,
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 determined by finger touch.・ ・ ・ ··················· No tack (2) Scratch resistance The hardened surface is scratched with steel wool # 0000, and is judged by the degree of scratching.・ ・ ・: Almost no damage △: slight damage ×: severe damage (3) Surface smoothness The obtained cured surface is observed and judged. ○ ・ ・ ・ Good × ・ ・ ・ ・ Slight disturbance

Examples 1-4 and Comparative Examples 1-2 Photocurable resin compositions shown in Table 1 were prepared. The sample for evaluation was polyethylene terephthalate (S-25 Teijin Limited)
The above composition was coated on a trade name of a company with a bar coater to a thickness of 4 microns using a high pressure mercury lamp (lamp input: 120 W / c).
m), at a conveyor speed of 30 m / min. At 1
What was hardened by irradiating ultraviolet rays repeatedly was used. As a photopolymerization initiator, Irgacure 500 (trade name of Ciba Geigy) was used.

Table 1 shows the evaluation results.

Examples 5 to 8 and Comparative Examples 3 to 5 Photocurable resin compositions shown in Table 2 were prepared. Using this, a cured product was prepared and evaluated under the same conditions as in Example 1. Table 2 shows the results. In Tables 1 and 2, polyfunctional monomer (a): pentaerythritol triacrylate polyfunctional monomer (b): trimethylolpropane triacrylate * Photopolymerization initiator: Irgacure-500 (photopolymerization initiator manufactured by Ciba-Geigy)

[0037]

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

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁷ identification code FI // C08G18 / 67 C08G18 / 67 C08L 101: 00 (58) Field surveyed (Int.Cl. ⁷ , DB name) C08F 290 / 00-290/14 C08F 299/00-299/08 C08F 2/46-2/50 C08J 7/04 C09D 4/00-4/06 C09D 175/00-175/16 C08G 18/00-18/87

Claims (1)

(57) [Claims] (1) (a) the following general formula (I) <Wherein, R ¹ is an alcohol residue having 5 to 10 carbon atoms, R ² is H or CH ₃ , and n represents an integer of 3 to 6 >
100 parts by weight of a compound represented by the formula (b): 0.1 to 12.5 parts by weight of a polyfunctional urethane acrylate [However, (b) is a polyol component and is represented by the following general formula (II): << In the formula, n is an integer of 10 to 25, and m1 and m2 are 0
Or an integer of 1 to 5, R represents a methyl group or a hydrogen atom >> and 1 mol of polydimethylsiloxanediol represented by the following general formula as a polyisocyanate component: In the formula, R represents an alkylene group having 1 to 10 carbon atoms, a phenylene group, or a substituted phenylene group. The prepolymer at the terminal of the isocyanate group obtained by reaction with 2 mol of the organic isocyanate represented by the formula: , The following general formula Wherein R ¹ is an alcohol residue having at least one hydroxyl group and having 5 to 10 carbon atoms, and R ² is H or CH ₃
And n represents an integer of 3 to 5 >>. The active energy ray-curable resin composition is characterized in that: