JP4650866B2 - UV-absorbing resin, resin composition for film formation using the same, and film peeling method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a coating agent having excellent weather resistance and durability to a base material such as metal, plastic, glass, ceramic, and wood, and a base material such as a painted surface, in particular, an ultraviolet ray having a protective function against ultraviolet rays. The present invention relates to a UV-absorbing resin used as an absorptive coating agent, a film-forming resin composition using the same, and a film peeling method.
[0002]
[Prior art]
Conventionally, UV absorbers such as benzophenone compounds and benzotriazole compounds are blended into acrylic ester polymers to block ultraviolet rays in sunlight, and this is used for metals, plastics, glass, ceramics, wood, etc. Application to the surface of a substrate is performed.
However, UV absorbers such as those mentioned above are generally poorly compatible with polymers, and when blended in large amounts, they become insoluble and impair transparency, and even if temporarily transparent at the time of application, bleeding and blooming over time Deterioration of performance and toxicity to ecology are problems. In order to solve these problems, a benzophenone-based or benzotriazole-based compound having a polymerizable double bond is homopolymerized or copolymerized with a polymerizable monomer (JP 9-3395, JP 9-12642, JP 9-202874) is known.
[0003]
[Problems to be solved by the invention]
However, the UV-absorbing polymer is often used outdoors exposed to sunlight, and the weather resistance is improved, but it is not sufficient, and there is a problem that the water resistance is poor.
This invention is made | formed in view of this situation, Comprising: It aims at providing the durable ultraviolet-absorbing polymer, the resin composition for film formation using the same, and a film peeling method.
[0004]
[Means for Solving the Problems]
That is, the ultraviolet absorbing resin of the present invention comprises a co-polymer comprising a reactive ultraviolet absorbing compound represented by the general formula (1) or (2) and a polymerizable dimethylpolysiloxane represented by the general formula (3) as essential components. Since it is a coalescence and has a dimethylpolysiloxane skeleton and an ultraviolet absorber skeleton, it has a structure that is stable to water, light, and heat. In addition, when a carboxyl group is introduced, the coating can be peeled off using an alkaline agent.
That is, the ultraviolet absorbing resin composition and the ultraviolet absorber according to the present invention are represented by the general formula (1).
[Chemical 8]
{Wherein X is a hydrogen atom or a halogen group, R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms,
R ² has the general structural formula —R ³ — (CH ₂ ) _{0 -2} -R ^4.
Where R ³ represents the presence or absence of a —O— group, —CH ₂ — group, or —CH (OH) — group, and R ⁴ represents the structural formula
Or [Chemical Formula 10]
(However, R ⁵ represents a hydrogen atom or a —CH ₃ group.)}
Or general formula (2)
Embedded image
{In the formula, Y is a hydrogen atom or a hydroxyl group, ^{R 6} is a hydrogen atom or ^{R 7} the same group, ^{R 7} is the general structural formula _{^{-R 8 - (CH 2) 0~2}} -R 9
Where R ⁸ represents the presence or absence of an —O— group, —CH ₂ — group, or —CH (OH) — group, and R ⁹ represents the structural formula
Or [Chemical Formula 13]
(However, R ¹⁰ represents a hydrogen atom or a —CH ₃ group.
It is group represented by these. }
Reactive UV-absorbing monomer represented by the general formula (3)
Embedded image
{Wherein R11 is a hydrogen atom or a methyl group R12 is a methyl group or a cyano group R13 is an alkylene group or an alkyleneoxy group (1 to 10 carbon atoms)
A represents an oxygen atom or an imino group a, an integer b of 0 to 6 represents an integer of 10 to 500. }
A dimethylpolysiloxane monomers UV absorbing resin obtained by reacting represented in the general formula (1) or the content of the polymer compound having a reactive ultraviolet absorption represented by (2) 0. It is 1 mass%-85 mass%, and the remainder is an ultraviolet-absorbing resin which is a polymerizable dimethylpolysiloxane represented by the general formula (3) .
In the present invention, the content of the polymerizable dimethylpolysiloxane represented by the general formula (3) in the polymer is 10% by mass to 70% by mass, and the balance is the general formula (1) or the general formula (2). It is a UV-absorbing resin that is a compound having a reactive UV-absorbing action .
Furthermore, the ultraviolet absorbing resin of the present invention can further contain an unsaturated carboxylic acid and / or a (meth) acrylic acid ester as a component constituting the polymer.
Moreover, in this invention, the acid value of resin can be 50-500.
Furthermore, the present invention provides such an ultraviolet absorbing resin , an aliphatic hydrocarbon solvent, an aromatic hydrocarbon solvent, a nitration and chlorinated hydrocarbon solvent, an alcohol solvent, a ketone solvent, an ether alcohol and an ether solvent. A solvent and an additive comprising a solvent, an ester, and an ether ester solvent are one or more additives selected from an oxidation stabilizer, a light stabilizer, an ultraviolet absorber, a fluidity improver, and a pigment. It is a resin composition for film formation.
Moreover, this invention is a method of removing a coating film by making the coating film which consists of such a resin composition for film formation react with the alkaline agent of pH8 or more.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the reactive ultraviolet absorber represented by the general formula (1) used in the present invention include 2- (2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl) -2H-benzotriazole, 2- (2 ′ -Hydroxy-5 '-(methacryloyloxypropyl) phenyl) -2H-benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-(methacryloyloxyethyl) phenyl) -2H-benzotriazole, 2- (2′-hydroxy-5′-t-butyl-3 ′-(methacryloyloxyethyl) phenyl) -2H-benzotriazole, 2- (2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl)- 5-chloro-2H-benzotriazole and the like can be mentioned. These can be used alone or in combination of two or more.
[0006]
Examples of the reactive ultraviolet absorber represented by the general formula (2) used in the present invention include 2-benzoyl-5- (2′-hydroxy-3′-methacryloyloxypropoxy) -phenol and 2-benzoyl-5. -(2'-methacryloyloxyethoxy) -phenol, 2-benzoyl-5- (2'-acryloyloxyethoxy) -phenol and the like. These can be used alone or in combination of two or more.
Moreover, there is no problem even if the reactive ultraviolet absorbers represented by the general formulas (1) and (2) are used in combination.
Examples of commercially available polymerizable dimethylpolysiloxane products represented by the general formula (3) include polymer azo polymerization initiators VPS-0501 and VPS-1001 (both manufactured by Wako Pure Chemical Industries, Ltd.).
[0007]
The content of the reactive ultraviolet absorber in the copolymer composition in the present invention is in the range of 0.1% by mass to 85% by mass, preferably in the range of 0.5% by mass to 80% by mass, and 1% by mass to The range of 50% by mass is more preferable.
If the content of the reactive ultraviolet absorber in the copolymer composition is less than 0.1% by mass, the ultraviolet absorption ability of the copolymer composition obtained is insufficient, such being undesirable. When the content exceeds 85% by mass, the concentration of the polymerizable dimethylpolysiloxane that is a polymerization initiator is lowered, and polymerization is difficult to occur.
Moreover, the content rate of polymeric dimethylpolysiloxane is the range of 10 mass%-70 mass%. If it is less than 10% by mass, the concentration as a polymerization initiator will be low and polymerization will be difficult to occur. Therefore, when the obtained copolymer is used as a paint, the film strength will be weak and the water resistance of the paint film will be poor. Become. If it exceeds 70% by mass, when the obtained copolymer is used as a paint, the (meth) acrylic acid ester, which is a film-forming component, cannot be blended sufficiently. Inferior to sex.
In addition to polymerizable dimethylpolysiloxane and reactive ultraviolet absorber, (meth) acrylic acid ester monomer and / or polymerizable unsaturated carboxylic acid monomer are added to the constituent components of the copolymer for polymerization. Thus, the physical properties of the polymer itself can be improved, and when this is applied as a paint to an object to be coated, the physical properties of the coating film can be improved.
[0008]
As a monomer that can be used in combination as a component of the copolymer of the present invention, examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, ( 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclododecyl (meth) acrylate, glycidyl (Meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate and the like can be mentioned.
Examples of the polymerizable unsaturated carboxylic acid monomer include (meth) acrylic acid, crotonic acid, itaconic acid, (anhydrous) maleic acid, fumaric acid and the like.
As necessary, aromatic unsaturated monomers such as styrene, halogen-containing unsaturated monomers such as vinyl chloride and vinylidene chloride, (meth) acrylamide, vinylpyridine, vinylimidazole, N, N′-dimethylamino Nitrogen-containing unsaturated monomers such as ethyl (meth) acrylate, unsaturated cyanide compounds such as (meth) acrylonitrile, vinyl esters such as vinyl acetate, vinyl ethers and the like can also be added.
The (meth) acrylic acid ester monomer and / or polymerizable unsaturated carboxylic acid monomer may be used alone or in combination of two or more.
[0009]
The coating film when a copolymer having a polymerizable unsaturated carboxylic acid as a structural component and an acid value of 50 to 500 is used as a coating material does not require protection of the coating object when the coating film becomes dirty. In this case, the film can be easily removed with an alkaline agent having a pH of 8 or higher.
When the acid value of the copolymer is less than 50, the solubility of the copolymer with an alkali agent is deteriorated, so that the film removal property is lowered, and when it exceeds 500, the water resistance of the coating film is lowered.
[0010]
The copolymer can be easily obtained by adding the above-described compound and solvent, purging with nitrogen, and stirring at a predetermined temperature.
Examples of the solvent used here include aliphatic alcohols such as methanol, ethanol, isopropanol and normal propanol, acetates such as ethyl acetate and butyl acetate, aromatic hydrocarbons such as toluene and xylene, N, N ′ -Dimethylformamide, chloroform, tetrahydrofuran, acetone and the like. These may be used alone or in combination of two or more.
For the purpose of adjusting the molecular weight, a chain transfer agent such as dodecyl mercaptan, 2-mercaptoethanol, carbon tetrachloride or a polymerization regulator may be used in the reaction system.
Furthermore, a polymerization initiator can be used for the purpose of polymerizing unreacted monomers after the copolymerization reaction. Examples of the polymerization initiator include radical polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, and di-t-butyl peroxide.
The copolymer obtained here may be used alone as a paint, or may be blended in a plastic or paint as an ultraviolet absorber.
[0011]
Further, the resin according to the present invention is prepared by using 4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, Di (2,2,6,6-tetramethylpiperidin-4-yl) -sebacic acid ester, di (1,2,2,6,6-pentamethylpiperidin-4-yl) -sebacic acid ester, 2- Light stability called HALS, such as (4-2,2,6,6-tetramethylpiperidine) -amino-2-methyl- (4-2,2,6,6-tetramethylpiperidine) -propionamide Can also be used in combination with an agent or an antioxidant.
Further, since the resin according to the present invention has excellent stability to light, titanium oxide, zinc oxide, tin oxide, zirconium oxide, niobium oxide, tungsten oxide, iron oxide, cadmium oxide, molybdenum sulfide, carbonized carbon It can be used in combination with a photocatalyst such as silicon, gallium arsenide, and cadmium sulfide.
[0012]
The resin of the present invention can be used alone or in combination with other resins as a film-forming resin composition.
Resins that can be used in combination include alkyd resins, amino alkyd resins, amino resins, vinyl resins, acrylic resins, polyester resins, epoxy resins, polyurethane resins, chlorinated rubber resins, cashew resins, and phenol resins. , Butyral resins, fluorine resins, silicone resins, natural resins, and the like. These resins may be used alone or in combination of two or more. .
Solvents that can be used include aliphatic hydrocarbon solvents, aromatic hydrocarbon solvents, nitration and chlorinated hydrocarbon solvents, alcohol solvents, ketone solvents, ether alcohols and ether solvents, esters and ether ester solvents. These resins may be used alone or in combination of two or more. .
Examples of the fluidity improver include thixotropic agents such as aluminum stearate, fatty acid amide, and organic bentonite, and leveling agents such as glycerin.
In addition, the resin of the present invention can be used as an ultraviolet absorber after volatilizing the solvent, such as polypropylene, polyethylene, polyethylene terephthalate, polystyrene, acrylonitrile-styrene resin, acrylonitrile-butadiene resin, polycarbonate, vinyl chloride and the like. It can be blended with plastic and kneaded.
Moreover, it can also mix | blend with rubbers, such as natural rubber, SBR, NBR, isoprene rubber, EPDM, and silicone rubber.
[0013]
As an alkaline agent for peeling a film made of a resin having an acid value of 50 to 500 according to the present invention, ammonia, water-soluble amino alcohols, water-soluble aliphatic amines and various alkali inorganic salts are appropriately dissolved in water. The pH is adjusted to 8 or higher, and a surfactant or the like can be added as necessary.
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited at all by these examples.
[0014]
【Example】
(Examples 1-6)
Table 1 shows the reaction type ultraviolet absorber represented by the general formula (1) or (2), the polymerizable dimethylpolysiloxane represented by the general formula (3), and the acrylic monomer in a 100 ml polymerization reactor. The mixture was charged in an amount, 25 g of tetrahydrofuran was added as a solvent, and the mixture was refluxed at a temperature of 60 ° C. with stirring in a nitrogen stream and reacted for 10 hours. After the reaction, 0.01 g of hydroquinone was added as a polymerization inhibitor to terminate the polymerization reaction, and the copolymer solutions of Examples 1 to 6 shown in Table 1 were obtained. A single peak was obtained in the GPC measurement of the nonvolatile content of the obtained copolymer solution. Moreover, the number average molecular weight in polystyrene conversion was calculated | required. The acid value was measured by a neutralization method.
(Comparative Example 1)
In a 100 ml polymerization reactor, the polymerizable dimethylpolysiloxane represented by the general formula (3), acrylic acid, and methyl methacrylate are charged in the blending amounts shown in Table 1, and 25 g of isopropyl alcohol is added as a solvent in a nitrogen stream. The mixture was reacted at a temperature of 70 ° C. for 6 hours with stirring. After the reaction, 0.01 g of hydroquinone was added as a polymerization inhibitor to terminate the polymerization reaction, and a copolymer solution of Comparative Example 1 shown in Table 1 was obtained. A single peak was obtained in the GPC measurement of the nonvolatile content of the obtained copolymer solution. Moreover, the number average molecular weight in polystyrene conversion was calculated | required. The acid value was measured by a neutralization method.
(Comparative Example 2)
A 100 ml four-necked flask is charged with the reactive ultraviolet absorber represented by the general formula (1) and methyl methacrylate in the amounts shown in Table 1, and 25 g of toluene is added as a solvent, and the mixture is stirred up to 80 ° C. The temperature rose. Then, 0.05 g of azobisisobutyronitrile was added as a polymerization initiator in a nitrogen stream and reacted at a temperature of 80 ° C. for 12 hours. After the reaction, 0.01 g of hydroquinone was added as a polymerization inhibitor to terminate the polymerization reaction, and a copolymer solution of Comparative Example 2 shown in Table 1 was obtained. A single peak was obtained in the GPC measurement of the nonvolatile content of the obtained copolymer solution. Moreover, the number average molecular weight in polystyrene conversion was calculated | required. The acid value was measured by a neutralization method.
[0015]
(performance test)
The performances of the copolymers obtained in Examples 1 to 6 and Comparative Examples 1 and 2 were evaluated by the method described below.
The copolymer solution obtained in each example and comparative example was directly applied to a clean glass plate with a cloth and dried, and the contact angle was measured to determine an alkaline agent having a pH of 8 (for example, ammonia water having a simple composition). The film removal property was determined. Further, the coated glass plate was immersed in water for 48 hours, and then pulled up and visually observed to determine transparency.
0.1 g of Solvent Yellow 151 dye is dissolved in ethanol, added to each copolymer solution, applied directly to a clean glass plate with a cloth and dried, and transmitted at a wavelength of 490 nm (maximum absorption wavelength of visible light). The rate was measured. Furthermore, it was exposed for 192 hours in a fade meter (FOM) test (specified in JIS B 7754), and the change in transmittance was examined.
[Table 1]
[0016]
[Effect of the present invention]
As is apparent from the results in Table 1, it was found that the copolymer of the present invention is a UV-absorbing polymer, and provides a resin composition for film formation and a film peeling method having weather resistance and water resistance.

Claims (6)

General formula (1)
{Wherein X is a hydrogen atom or a halogen group, R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms,
R ² has the general structural formula —R ³ — (CH ₂ ) _{0 -2} -R ^4.
However, R ³ represents the presence or absence of an —O— group, —CH ₂ — group, or —CH (OH) — group, and R ⁴ represents a structural formula.
Or
(Wherein, ^{R 5} represents a hydrogen atom or -CH ₃ group.
It is group represented by these. )}
Or general formula (2)
{In the formula, Y is a hydrogen atom or a hydroxyl group, ^{R 6} is a hydrogen atom or ^{R 7} the same group, ^{R 7} is structural formula _{^{-R 8 - (CH 2) 0~2}} -R 9
However, R ⁸ indicates that the —O— group, —CH ₂ — group, or —CH (OH) — group is present or absent, and R ⁹ represents the structural formula.
Or
(However, R ¹⁰ represents a hydrogen atom or a —CH ₃ group.
It is group represented by these. )}
And a compound represented by the general formula (3)
(Wherein R11 is a hydrogen atom or methyl group R12 is a methyl group or cyano group R13 is an alkylene group or an alkyleneoxy group (1 to 10 carbon atoms))
A represents an oxygen atom or an imino group a, an integer b of 0 to 6 represents an integer of 10 to 500. )
The content of the compound represented by the general formula (1) or (2) having a reactive ultraviolet absorbing action in the polymer is 0.1. An ultraviolet-absorbing resin, which is a polymerizable dimethylpolysiloxane having a mass% to 85 mass% and the balance being represented by the general formula (3). The content of the polymerizable dimethylpolysiloxane represented by the general formula (3) in the polymer is 10% by mass to 70% by mass, and the balance is the reactive ultraviolet absorption represented by the general formula (1) or the general formula (2). UV-absorbing resin that is a compound with action . The ultraviolet absorbing resin according to claim 1 or 2 , further comprising an unsaturated carboxylic acid and / or a (meth) acrylic acid ester as a component constituting the polymer. The ultraviolet-absorbing resin according to claim 3 , wherein the acid value of the resin is 50 to 500. The ultraviolet absorbing resin according to claim 3 or 4 , an aliphatic hydrocarbon solvent, an aromatic hydrocarbon solvent, a nitration and chlorinated hydrocarbon solvent, an alcohol solvent, a ketone solvent, an ether alcohol And an ether solvent, an ester and an ether ester solvent, and an additive that is one or more selected from an oxidation stabilizer, a light stabilizer, an ultraviolet absorber, a fluidity improver, and a pigment A film-forming resin composition comprising: The method of removing a coating film by making the coating film which consists of a resin composition for film formation described in Claim 5 react with the alkaline agent of pH8 or more.