JP2002012634A - Ultraviolet-curing composition for masking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means capable of completely automating a masking process in automobile coating. SOLUTION: This ultraviolet-curing masking composition comprises (A) a photocurable resin (e.g. urethane (meth)acrylate oligomer) and (B) a specific (meth)acrylate [e.g. CH2=CR1COOR2 (R1 is hydrogen or a methyl group; R2 is a 4-24C alkyl group) or the like] as main components in the weight ratio of the component (A)/(B) of 5-30/50-90. The composition may further contain a thermoplastic resin, a filler, a photoreaction initiator, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substitute material for a masking tape used in painting. More specifically, the present invention relates to an ultraviolet-curable masking material that can be applied to an adherend, is cured by ultraviolet irradiation, and is peelable together with a coating film after a coating step.

[0002]

2. Description of the Related Art Conventionally, masking in a coating process has been performed using a masking tape. That is,
The part to be masked is covered with a masking tape, and a coating and drying process is performed on the masking tape.
Had been peeled off.

[0003]

However, the application of the masking tape is usually done manually, which is one of the steps which is difficult to automate in a car production line.
Some automakers have already introduced a sticking robot for sticking the masking tape, but this is only a straight line part, and the corners and the like are done manually. Thus, complete automation of the masking process is desired.

[0004]

The present invention relates to (A) a photocurable resin; and (B) CH ₂ ＣＲCR ¹ COOR ² , CH ₂ ＣＲCR ¹ CO (O
C ₂ H ₄ ) _n O-φ-C _X H _{2 X + 1} , CH ₂ = CR ¹ CO (OC
₃ H ₆ ) _n O-φ-C _X H _{2X + 1} (wherein R ¹ represents hydrogen or a methyl group, R ² represents a C ₄ -C ₂₄ alkyl group, and φ represents Represents a phenyl group, n represents a number of 1 to 10, x represents a number of 0 to 18), isobornyl
(Meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate and dicyclopentenyloxyethylene (meth) acrylate, selected from the group consisting of one or more (meth) acrylate monomers as a main component, When the weight ratio of A) / (B) is 5 to 30
(1) a UV-curable masking composition having a ratio of / 50 to 90.

The present invention further comprises (C) a thermoplastic resin, wherein the weight ratio of (A) / (B) / (C) is 5 to 30/5.
The composition (1), which is 0 to 90/0 to 30.

Further, the present invention further comprises (D) a filler, and the weight ratio of (D) to the total weight of the composition is 5 to 20%.
(3) related to the composition (1) or (2), wherein

[0007] The present invention also relates to (4) the above compositions (1) to (3), which further contain a photoreaction initiator.

Further, the present invention provides the composition (1)
(4) is applied on an adherend so that the thickness of all parts where the adherend and the composition are in contact with each other is 50 μm or more, and then cured to seal the sealing material on the adherend. A method of forming (5).

The present invention also relates to a method of removing the sealing material by continuously peeling the sealing material with a spatula (6).

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The photocurable resin of the component (A) according to the present invention is not particularly limited, but acrylate oligomers which can be cured by ultraviolet rays (for example, urethane (meth) acrylate oligomer), epoxy (meth) acrylate oligomer , Butadiene acrylate oligomer) are preferable, and a urethane acrylate oligomer is more preferable from the viewpoint of imparting adhesion to the adherend, flexibility and toughness to the cured product. Also, two or more kinds may be included.

In the composition, component (A), component (B) and component (C)
Weight ratio of component (A) to the total weight of
0% by weight.

The component (B) according to the present invention comprises CH ₂ ＣＲCR ¹
COOR ² , CH ₂ = CR ¹ CO (OC ₂ H ₄ ) _n O-φ-C
_X H _{2X + 1} , CH ₂ ＣＲCR ¹ CO (OC ₃ H ₆ ) _n O-φ-C _X
H _{2X +1} (wherein, R ¹ represents hydrogen or a methyl group, R ² represents a C ₄ -C ₂₄ alkyl group, φ represents a phenyl group, and n represents 1-10 Where x is 0 to
18), isobornyl (meth) acrylate,
Cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate and dicyclopentenyloxyethylene (meth) acrylate, selected from the group consisting of:
One or more (meth) acrylate monomers. In particular,
It is preferable to reduce the viscosity of the entire composition, impart releasability to the adherend to the composition, and reduce adhesion to the adherend. Specifically, (meta)
It is preferable that the length of the alkyl group carbon chain in the ester portion of the acrylate ester is 4 to 24, and that the ester portion has an ethylene oxide chain, a propylene oxide chain, or a phenylene oxide chain. Further, it is preferable that the molecular weight is large and the boiling point is high because the odor is reduced.

The weight ratio of the component (B) to the total weight of the components (A), (B) and (C) is 50 to 9
0% by weight.

[0014] The thermoplastic resin of the component (C) according to the present invention is not particularly limited, but preferably has good compatibility with the components (A) and (B). Specifically, for example, polyethylene, polyester, polypropylene, polybutylene, polybutadiene, polybutene, polyisoprene,
Polyvinyl butyral, polyphenylene oxide, polysulfone, polycarbonate, poly-p-xylene, E
VA, EEA, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene, chlorinated polypropylene, phenoxy resin, fluororesins, polyacetal, polyamideimide, polyarylate, polystyrene, methacrylic resin, methylpentene polymer, polyacrylonitrile , Polyethers, silicones, polyamide derivatives, polyketones, thermoplastic epoxy resins,
And copolymers thereof. Also, two or more kinds may be included.

The weight ratio of the component (C) to the total weight of the components (A), (B) and (C) is from 0 to 30% by weight. The thermoplastic resin is used for imparting toughness to the cured product when adjusting the viscosity before curing or peeling off the sealing material (after curing) of the present invention. Therefore, the component (C) may not be contained in the scraping-off type peeling which does not always require toughness.

The filler of the component (D) according to the present invention is not particularly limited, but those which do not impair the ultraviolet transmittance of the whole system and have no corrosiveness are preferred. More preferably, the entire system is made thixotropic, construction is facilitated, and shape retention after construction and shape modification can be easily performed. Specifically, those having a small particle size such as silicic anhydride and aluminum oxide are preferable, but other inorganic fine particles and organic fine particles can also be used.

The weight ratio of (D) is preferably from 5 to 20% based on the total weight of the composition.

Further, the composition according to the present invention may contain a photoreaction initiator as an optional component. The content is
Preferably, it is 0.5 to 5 with respect to the weight of the ultraviolet curing resin.
% By weight. The photoreaction initiator is selected according to the ultraviolet absorption wavelength band of the resin composition.

Further, other additives may be contained. For example, non-reactive additives that do not remain or leave traces after the masking material has been stripped can be used to further improve strippability. For example, surfactants, oils and the like can be mentioned. The content is preferably from 1 to 20% by weight based on the total weight of the composition.

The composition according to the present invention contains the components (A) and (B) as main components. Here, the main component is
It means that the total content of the components (A) and (B) is 60 to 100% based on the total weight of the composition.

The peel strength of the composition according to the present invention is from 0.2 to
It is preferably in the range of 0.5 N / 25 mm. Also,
The peeling force after painting and drying (dry coating thickness 120μm)
It is preferably in the range of 0.4 to 2 N / 25 mm with the coating film on. The “peeling force” referred to in this specification is
A value measured after applying the composition according to the present invention to an electrodeposition coated steel sheet with a width of 25 mm and a thickness of 3 mm and curing by irradiation with ultraviolet rays (180 ° peeling at 23 ° C., peeling speed 300 mm / min)
Say.

Next, an example of a method for producing the composition according to the present invention will be described. First, when using the thermoplastic resin of the component (C), the component (C) is added to and dissolved in the monomer of the component (B). Next, the oligomer of the component (A) is added to and dissolved therein. Next, when the filler of the component (D) is used, the component (D) is added thereto and dispersed. Next, when a photoreaction initiator is used, the photoreaction initiator is added and dissolved therein. Finally, after defoaming with a defoaming machine, the container is filled.

Next, the method of using the composition according to the present invention will be described. First, the composition according to the present invention is applied on an adherend in the form of a thin sheet, and then cured by irradiation with ultraviolet rays.
After curing, the usual coating process (160 ° C x 30 minutes, 3-4
), The cured sealing composition is peeled off together with the coating by an automated machine such as a robot. At the time of peeling, the cured sealing composition may be peeled off by pulling its end, but may be scraped off with a spatula. At this time, when the hardened masking material is to be peeled off, the thicker portion of the masking material is easily peeled off, but the thinner portion is easily torn off and remains on the adherend (FIG. 4). Therefore, when the coating is applied with a thick end portion, even a relatively brittle material can be easily peeled off. Specifically, an ultraviolet-curable masking composition,
When applying to an adherend, it is preferable to apply in a shape as shown in FIGS. In addition, when it is not possible to apply such a shape, as shown in FIG.

[0024]

By using the preferred composition according to the present invention, it does not sag or drop before curing even in a vertical part or a ceiling part, and can be applied to any part of a straight part, a corner part, a curved surface part, and an uneven part. However, it can be automatically applied with a sealing gun. In addition, it has excellent shape retention even after application, and also excellent releasability of the cured masking material.

[0025]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to this.

Examples 1 to 7 The formulations of Examples 1 to 7 in the separate table were applied to an electrodeposition coated steel sheet with a sealer gun to a width of about 25 mm and a thickness of about 3 mm with a substantially uniform thickness. Immediately after irradiation with a high-pressure mercury lamp (80 W / cm) for about 3 seconds, the surface was completely cured without tack. Almost no smoke was emitted and no odor was emitted during ultraviolet irradiation. From above, undercoating, intermediate coating, and topcoating (solvent type) were performed, and each was 160 ° C x 3
Heat drying was performed for 0 minutes. The thickness of each coating is 30-45μm
The total was about 120 μm. After the temperature of the vehicle body dropped to near room temperature, the coating film was broken with a Teflon (registered trademark) spatula, and the cured peelable composition was easily peeled off when it was scooped off. Although the peelable composition was partially left at the end, it could be easily peeled off by rubbing again with a spatula. There was no contamination or traces at the peeled part.

Comparative Examples 1 to 3 As in the same manner as in the examples, the adhesion was good, and it was attempted to peel off with a spatula, but it was difficult to peel off.

[0028]

[Table 1]

In Table 1, 1 is from Mitsui DuPont, 2 is Nippon Gohsei, 3 is Kuraray, 4 is Toyobo, and 5 is JSR. )
6 is from Toa Gosei Chemical Industry Co., Ltd., 7 and 8 are from Nippon Synthetic Chemical Industry Co., Ltd., 9 is from Showa Polymer Co., Ltd., and 10 is Kyoeisha Yushi Kagaku Kogyo Co., Ltd. ｛CH ₂ ＣＨCHC.
O (OC ₂ H ₄ ) ₈ O-φ-C ₉ H ₁₉ , 11 is from Kyoeisha Yushi Kagaku Kogyo Co., Ltd. {CH ₂ = CHCOOC ₁₈ H ₃₇ }, and 12 is Kyoeisha Yushi Kagaku Kogyo Co., Ltd. CH ₂ = CHC
13 from OOC ₁₂ H ₂₅ %, Toa Gosei Chemical Industry Co., Ltd.
{CH ₂ = CHCOOCH ₂ CH (OH) CH ₂ O-φ}
14 is Kyoeisha Yushi Kagaku Kogyo Co., Ltd. ｛CH ₂ ＣＨCH
From CO (OC ₂ H ₄ ) ₄ O-φ-C ₉ H ₁₉ , 15 is Toa Gosei Chemical Industry Co., Ltd. {CH ₂ ＣＨCHCO (OC ₃ H ₆ ) _2.5
O-φ-C ₉ H ₁₉ }, 16 from Toa Gosei Chemical Industry Co., Ltd. (isobornyl acrylate), and 17 from Kyoeisha Yushi Kagaku Kogyo Co., Ltd. {CH ₂ = CHCOOC ₂ H ₄ O}.
From H｝, 18 is Kyoeisha Yushi Kagaku Kogyo Co., Ltd. ｛CH ₂ =
CHCOOCH ₂ CH (OH) CH ₃ }, 19 are commercial products from Nippon Aerosil Co., Ltd., and 20 are commercial products from Merck Co., Ltd.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first state in which a composition according to the present invention has been applied onto an adherend.

FIG. 2 is a diagram showing a second state in which the composition according to the present invention has been applied onto an adherend.

FIG. 3 is a diagram showing a third state in which the composition according to the present invention has been applied onto an adherend.

FIG. 4 is a diagram showing a fourth state in which the composition according to the present invention has been applied onto an adherend.

[Explanation of symbols]

 Reference Signs List 1 UV-curable masking composition 2 Adherend

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 5/00 C09D 5/00 Z G03F 7/004 511 G03F 7/004 511 7/027 502 7/027 502 (72) Inventor Yoshio Kishimoto 2-3-3 Sekiguchi, Bunkyo-ku, Tokyo F-term in Nichiban Co., Ltd. (reference) 2H025 AA14 AA16 AB20 AC01 AD01 BC34 BC83 CA00 CB01 CC08 FA03 FA12 4J011 PA07 PA13 PA65 PA66 PA67 PA68 PA69 PA88 PA90 PA96 PA98 PA99 PC02 PC08 SA90 WA02 4J027 AA04 AC03 AC04 AC06 AE01 AG01 BA07 CA02 CA03 CA04 CA05 CA06 CA07 CA08 CA10 CA18 CA20 CB10 CD08 4J038 CA022 CA102 CB032 CB052 CB062 CB092 CB112 CH072 CG172 CG172 CG172 DA012 DB002 DB362 DC012 DD002 DE002 DF052 DF062 DG212 DJ052 DK012 DL032 KA03 KA08 NA24 NA27 PA17 PB07 P B08

Claims (6)

[Claims] (A) a photocurable resin; and (B) CH ₂ ＣＲCR ¹ COOR ² , CH ₂ ＣＲCR ¹ CO (O
C ₂ H ₄ ) _n O-φ-C _X H _{2 X + 1} , CH ₂ = CR ¹ CO (OC
₃ H ₆ ) _n O-φ-C _X H _{2X + 1} (wherein R ¹ represents hydrogen or a methyl group, R ² represents a C ₄ -C ₂₄ alkyl group, and φ represents Represents a phenyl group, n represents a number of 1 to 10, x represents a number of 0 to 18), isobornyl
(Meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentenyl (meth) acrylate and dicyclopentenyloxyethylene (meth) acrylate, selected from the group consisting of one or more (meth) acrylate monomers as a main component, When the weight ratio of A) / (B) is 5 to 30
/ 50 to 90, an ultraviolet-curable masking composition. 2. The composition according to claim 1, further comprising (C) a thermoplastic resin;
/ (B) / (C) weight ratio is 5-30 / 50-90 / 0
The composition of claim 1, wherein the composition is 30. 3. The composition according to claim 1, further comprising (D) a filler, wherein the weight ratio of (D) to the total weight of the composition is 5 to 20%. 4. The composition according to claim 1, further comprising a photoreaction initiator. 5. The composition according to any one of claims 1 to 4, wherein the composition has a thickness of 50 μm or more on all parts where the composition is in contact with the composition. A method of forming a sealing material on an adherend after applying it to a substrate. 6. A method for removing the sealing material according to claim 5 by continuously peeling it off with a spatula.