JP3088781B2 - Adhesive, surface protection sheet, surface protection metal plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive for a surface protection sheet having excellent drawability, a surface protection sheet provided with the pressure-sensitive adhesive on a plastic film, and the surface protection sheet provided on a surface of a metal plate. Metal plate.

[0002]

2. Description of the Related Art Conventionally, in order to prevent the occurrence of partial abrasions caused by a mold during plastic working such as punching, cutting, bending, and drawing of a metal plate such as an aluminum plate, a stainless steel plate, a steel plate, and a painted plate thereof. A surface protection sheet is used. A conventional general surface protection sheet has a defect (hereinafter referred to as floating) that it is naturally peeled off from its surroundings due to various conditions added in the intermediate steps during these processing. When floating occurs, the film breaks and overlaps, leaving a dent on the metal plate during drawing. In order to suppress such lifting, it is necessary to strengthen the adhesive force between the adhesive and the metal plate. However, if the adhesive force is too strong, it is difficult to peel off the surface protective sheet after drawing. is there. Various proposals have heretofore been made as a surface protection sheet for drawing a metal plate, but few of them have characteristics sufficient to withstand a high degree of drawing, and are applied only to light processing.

[0003]

SUMMARY OF THE INVENTION The first object of the present invention is to provide an adhesive for a surface protective sheet,
Adhesion that causes extremely little floating phenomenon of the surface protection sheet during drawing of the metal plate whose surface is protected by the surface protection sheet, and has an appropriate adhesive strength and can easily peel off the surface protection film. To provide an agent. A second object of the present invention is to provide a surface protection sheet which has extremely low occurrence of a floating phenomenon during drawing of a metal plate, has an appropriate adhesive strength, and can be easily peeled off. A third object of the present invention is to provide a surface protection metal plate that has extremely low occurrence of a floating phenomenon of a surface protection sheet at the time of drawing, and thus has extremely few dents left on the metal plate at the time of drawing. is there.

[0004]

Means for Solving the Problems The present inventors have conducted various studies on the search for a pressure-sensitive adhesive composition which has solved the above-mentioned problems. As a result, the present inventors have found that an acrylate-based copolymer is mainly used, and a phosphate-based interface is used. Prevents lifting by using an activator and a three-component pressure-sensitive adhesive containing one or both of an alkylphenol resin and a terpene-modified phenolic resin, particularly a pressure-sensitive adhesive containing these components in a specific ratio. The present inventors have found that an improved surface protection sheet can be obtained, and have completed the present invention.

That is, the gist of the present invention is: 1) An adhesive containing the following components (A), (B) and (C). (A) Acrylic ester copolymer. (B) a phosphate ester-based surfactant. (C) at least one selected from alkylphenol resins and terpene-modified phenol resins. 2) A surface protection sheet provided with the above-mentioned one or two pressure-sensitive adhesive layers on a plastic film. 3) A surface protection metal plate to which the surface protection sheet is attached. Exists.

As the acrylate-based copolymer (A) in the present invention, it is sufficient to use those known in the art. For example, acrylic acid or methacrylic acid as the main component is an alkyl having 12 or less carbon atoms. Esters are used. For example, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, Copolymers using one or two or more of (meth) acrylic acid dodecyl esters and the like and copolymers of one or more of these esters with one or more monomers copolymerizable are exemplified. For example, a main monomer such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and a comonomer such as vinyl acetate, acrylonitrile, styrene, and methyl methacrylate are further combined with (meth) acrylic acid to improve crosslinking and adhesion. And copolymers of functional group-containing monomers such as hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, acrylamide, glycidyl methacrylate, and maleic anhydride. The polymerization is carried out by a usual solution or emulsion polymerization method of these monomers. It is desirable that the obtained pressure-sensitive adhesive is further crosslinked with a polyisocyanate, an epoxy compound, a melamine compound, or the like.

[0007] Phosphate-based surfactants (B) include alkylphenol-type phosphates, higher alcohol phosphate monoesters (salts), higher alcohol phosphate diesters (salts), higher alcohol phosphate triesters (salts). And so on. These compounds are generally used in an amount of 0.001 to 1.0 part by weight, preferably 0.01 to 0.1 part by weight, per 100 parts by weight of the (A) acrylate copolymer.
By blending 5 parts by weight, the specific effects of the present invention can be obtained. When the amount is less than 0.001 part by weight, the effect of the addition cannot be substantially obtained. Therefore, the metal plate surface may be contaminated, which is not preferable.

The amount of the alkylphenol resin or terpene-modified phenol resin (C) used in the present invention is usually 1 to 20 parts by weight, preferably 5 to 10 parts by weight, per 100 parts by weight of the acrylate copolymer. Parts by weight. If the amount is less than 1 part by weight, the desired effect cannot be substantially obtained. If the amount is more than 20 parts by weight, the adhesive strength between the metal plate and the surface protective film increases, making peeling difficult.

The pressure-sensitive adhesive of the present invention comprises the above (A), (B),
The three components (C) are constituted as essential components, and a desired effect is achieved by using these three components in combination. If necessary, fillers, softeners, tackifiers and antioxidants commonly used in this field may be appropriately added.

The surface protective sheet of the present invention is usually prepared as follows. That is, (A), (B), (C)
Is dissolved or dispersed in a suitable medium (for example, toluene, ethyl acetate, methyl ethyl ketone, etc.), and this is mixed with a suitable plastic film (for example, a polyalkylene such as polyethylene or polypropylene or a blend thereof). , A plastic film such as vinyl chloride) to form an adhesive layer. The thickness of the plastic film is usually 20 to 200 μm, preferably 3 to 200 μm.
The thickness of the pressure-sensitive adhesive layer after drying is usually 1 to 20 μm, preferably 3 to 10 μm. When the surface protective film thus obtained is adhered to a metal plate, a surface protective metal plate excellent in various physical properties such as drawability, adhesiveness, and peeling workability can be obtained.

[0011]

The present invention will be described more specifically with reference to the following examples. In addition, "parts" indicates parts by weight. Example 1 In ethyl acetate, a 25% concentration acrylate-based copolymer composed of butyl acrylate (80 mol), acrylic acid (10 mol), and methyl methacrylate (10 mol) was prepared. The viscosity of the resulting solution was 8,000 centipoise. For 100 parts (solid content) of this solution,
5 parts of a cross-linking agent [polyisocyanate, manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate L] was added to obtain a pressure-sensitive adhesive composition, and 100 parts (solid content) of this composition was treated with a phosphate-based interface. Activator [manufactured by Toho Chemical Industry Co., Ltd.
0.3 parts of trade name GAFAC-RL-210] and 3 parts of an alkylphenol resin (trade name Tamanol 610, manufactured by Arakawa Hayashi Co., Ltd.) were added to obtain a pressure-sensitive adhesive for a surface protective sheet of the present invention. A 30% toluene solution of this adhesive is applied to a thickness of 50
It was applied on a micron polyethylene film and dried. The coating thickness of the adhesive after drying was 10 microns. The obtained surface protection sheet was stuck on a 0.7 mm thick stainless steel plate (SUS-304-BA finish), and the stuck plate was punched with a diameter of 100 mmφ to a depth of 20 mm and 50 m.
An mφ cup test was performed. Table 1 shows the results.

Example 2 The alkylphenol resin Tamanol 6 in Example 1
Sumilite resin [Sumitomo Durez Co., Ltd.]
Terpene phenol resin] was used in the same manner as in Example 1 except for the above. Table 1 shows the results of the cup test.

[0013]

COMPARATIVE EXAMPLE In Example 1, a comparative example was carried out under the same conditions as in Example 1, except that no alkylphenol resin was added (Comparative Example 1) and no phosphoric acid ester was added (Comparative Example 2). Table 1 shows the results of the cup test.

[0014]

[Table 1]

[0015]

As described above, according to the present invention, when used as a pressure-sensitive adhesive for a surface protective sheet, the metal sheet protected by the surface protective sheet is subjected to a drawing process at the time of drawing. A pressure-sensitive adhesive is provided in which the occurrence of a floating phenomenon is extremely small, and the pressure-sensitive adhesive has an appropriate adhesive force and can easily peel a surface protective film from a metal plate.
Further, according to the present invention, when used for surface protection of a metal plate, the occurrence of a floating phenomenon at the time of drawing of the metal plate is extremely small, and it can be easily peeled off with an appropriate adhesive force. A surface protection sheet is provided. Furthermore, according to the present invention, there is provided a surface protection metal plate in which the occurrence of a floating phenomenon of the surface protection sheet during the drawing process is extremely small, and furthermore, a dent is hardly left on the metal plate during the drawing process.

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI // (C09J 133/06 161: 14) (C09J 161/14 133: 06) (56) References JP-A-59-93771 (JP, A JP-A-53-79930 (JP, A) JP-A-53-94519 (JP, A) JP-A-2-2066671 (JP, A) JP-A-49-96054 (JP, A) JP-A-52-945 62347 (JP, A) JP 29-1997 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09J 133/06 C09J 161/14 C09J 7/02 B32B 7/12- 7/14 B32B 15/08

Claims (4)

(57) [Claims] 1. A surface protection sheet for a metal plate comprising the following components (A), (B) and (C):
Of the pressure-sensitive adhesive. (A) Acrylic ester copolymer. (B) a phosphate ester-based surfactant. (C) at least one selected from alkylphenol resins and terpene-modified phenol resins. 2. (A) Acrylic ester copolymer 1
00 parts by weight, (B) phosphate ester-based surfactant 0.0
2. The pressure-sensitive adhesive according to claim 1, wherein the pressure-sensitive adhesive contains 0.1 to 1.0 part by weight and at least 1 to 20 parts by weight of (C) an alkylphenol resin and a terpene-modified phenol resin. 3. A plastic film on to claim 1 or protect surfaces coercive formed by providing an adhesive layer according to any one of the 2
Sheet over the door. 4. A surface-protecting metal plate comprising the surface of the metal plate and the surface protection sheet according to claim 3.