JPS6253346B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an acrylic board with a protected aesthetic surface, and more specifically, the invention relates to an acrylic board with a protected aesthetic surface, and more specifically, an acrylic board with an extremely excellent usability effect between the aesthetic surface on both sides or one side of the acrylic board and a covering base material made of paper or the like. A surface protective layer made of a pressure-sensitive adhesive composition is formed at the same time as the acrylic plate and the coating substrate are integrated, so that the above-mentioned aesthetic surface can be protected at low cost. That is, an attempt is made to provide an inexpensive product that has excellent removability even after a surface protective layer has been adhered for a long period of time, and that does not cause contamination of the aesthetic surface of the acrylic board by the protective layer even after being peeled off. Regarding the structure according to the present invention, the following (A) (B) (c)
It is formed from an acrylic copolymer resin composition in which an appropriate amount of amines is added as a crosslinking agent to a water-dispersed emulsion formed by emulsion polymerization of components, and it is used together with the above-mentioned coating base material to coat an acrylic board. It is characterized in that a pressure-sensitive adhesive composition that can be re-peelable from both sides or one side is formed as a protective layer at the same time as the acrylic plate and the coating substrate are integrated. (A) Main component monomer (1) Acrylic acid or methacrylic acid alkyl ester having an alkyl group containing 6 to 12 carbon atoms; and (2) Acrylic acid or methacrylic acid alkyl ester having an alkyl group containing 5 or less carbon atoms. Acid alkyl ester (B) Functional monomer (3) N-alkylolamide of acrylic or methacrylic acid (4) Glycidyl acrylate and glycidyl methacrylate (5) Allyl glycidyl ether (c) Functional monomer (6) α-olefin carbon Acids (However, for (3), (4), and (5), any of them can be used alone or in an appropriate combination of several kinds) Next, in the diagrams showing examples of the present invention,
1 is an acrylic board; 2 is a covering base material made of paper, synthetic resin film, or sheet; 3 is a surface protective layer for the aesthetic surface; 1 and the covering base material 2 are integrated. FIG. 1 shows a case where surface protective layers 3, 3 are formed on both sides of the acrylic plate 1, and FIG. 2 shows a case where a surface protective layer 3 is formed on one side of the acrylic plate 1. The pressure-sensitive adhesive composition as the surface protective layer 3 is removable from both sides or one side of the acrylic plate 1 together with the coating base material 2, and is as follows (A), (B), and (c).
It is formed from an acrylic copolymer resin composition obtained by adding an appropriate amount of amines as a crosslinking agent to a water-dispersed emulsion formed by emulsion polymerization of three components. (A) Main component monomer (1) Acrylic acid or methacrylic acid alkyl ester having an alkyl group containing 6 to 12 carbon atoms; and (2) Acrylic acid or methacrylic acid alkyl ester having an alkyl group containing 5 or less carbon atoms. Acid alkyl ester (B) Functional monomer (3) N-alkylolamide of acrylic or methacrylic acid (4) Glycidyl acrylate and glycidyl methacrylate (5) Allyl glycidyl ether (c) Functional monomer (6) α-olefin carbon Acids (However, for (3), (4), and (5), use any of them alone or in an appropriate combination) In this invention, the above (1) to (1) as components (A), (B), and (C) are used.
The preferred weight ratio of (6) can be exemplified as follows. (A) (1)...20-90% (2)...20-80% (B) Any one or more of (3)(4)(5)...20-90% (C) ( 6)...2.0 to 15.0% (wt%) In addition, in practice, an anionic and nonionic mixed activator is used as an emulsifier for the monomer having the composition of components (A), (B), and (C) above, Emulsion copolymerization is carried out using persulfates as a polymerization initiator and water as a dispersion medium. An appropriate amount of amines is added as a crosslinking agent to the polymer emulsion thus obtained. These amines include (a) aliphatic polyamines such as diethylene polyamine, triethylene tetramine, polymethylene diamine, tetraethylene pentamine, diethylaminopropylamine, N-aminoethylpiperidine, polyether diamine, menthanediamine, N-aminoethyl Examples of piperazine, m-xylene diamine or modified aliphatic polyamine include N,N'-bishydroxyethyl and N,N'-bishydroxypropylene diamine. (b) Aromatic amines such as m-phenylenediamine, diaminophenol, diaminodiphenylsulfone, benzidine, O-toluidine, 4,4'-thiodianiline, O-chloroaniline, 2,4-toluenediamine, diaminoditrisulfone , 4-chloro-O-phenylenediamine, m-aminobenzylamine, and the like. (c) Secondary and tertiary amines For example, secondary amines include N-methylpiperazine, pyrrolidine, and morpholine, and tertiary amines include linear diamine, tetramethylguanidine, triethanolamine, N,N,
Examples include N',N'-tetramethyl-1,3-butanediamine, N,N'-dimethylpiperazine, hexamethylenetetramine, pyridine, pyrazine, quinoline, benzyldimethylamine, and α-methylbenzylmethylamine. The most characteristic features of the adhesive composition according to the present invention produced as described above are: (a) crosslinking between carboxylic acid and alkylolamide; (b) crosslinking between alkylolamides; in this case, the remainder of the polymerization initiator NH ₄ CI, P-toluenesulfonic acid, etc. act as a persulfate or a catalyst to cause a radical reaction and an acidic condensation reaction, thereby significantly increasing the crosslinking rate. (c) Crosslinking between carboxylic acid and epoxy group In this case, an acidic catalyst such as P-toluenesulfonic acid acts as a catalyst to significantly increase the crosslinking rate. (d) Crosslinking between epoxy groups and the above-mentioned amines An emulsion of a highly elastic polymer composition obtained by a crosslinking reaction in combination of at least two of the above four types of crosslinking is used as a pressure-sensitive adhesive composition. Can be used as Further, basic monomers in the composition according to the present invention include hexyl acrylate as an acrylic acid or methacrylic acid alkyl ester having 6 to 12 carbon atoms;
These include n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, decyl acrylate, or their methacrylates. Examples of monomers of acrylic acid or methacrylic acid alkyl esters having 5 or more carbon atoms include pentyl acrylate, n-butyl acrylate, isobutyl acrylate, ethyl acrylate, methyl acrylate, and their methacrylates. The preferred usage ratio of acrylic acid alkyl esters or methacrylic acid alkyl esters is 70
~90% (wt%), and within that range, the glass transition temperature is adjusted at an appropriate point by combining a monomer with an alkyl group of 6 to 12 carbon atoms and a monomer with an alkyl group of 5 or less. If a large amount of monomers having carbon number of 5 or less is used, the glass transition temperature becomes high, making it unsuitable for use in protective adhesive sheets. In addition, copolymerizable vinyl monomers, such as vinyl acetate, styrene, and acrylonitrile, which use a large amount of alkyl groups with 6 to 12 carbon atoms and can partially replace acrylic acid alkyl esters with 5 or less carbon atoms, are used. The amount that can be replaced by a polymer having a glass transition temperature of 30 DEG to 106 DEG C. is 5% by weight or less. Examples of crosslinking monomers include N-alkylolamides of acrylic acid or methacrylic acid, glycidyl acrylate, glycidyl methacrylate, and allyl glycidyl ether. N-alkylolamides include N-methylol acrylamide,
These include N-ethyloacrylamide, N-propanol acrylamide, N-terbutylacrylamide, diacetone acrylamide, and the like. Among these monomers, N-methylol acrylamide, glycidyl methacrylate, and glycidyl acrylate exhibit preferable effects. Monomers effective as α-olefin type carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, and the like. Effective monomers that can be added to the emulsion as a crosslinking agent include (a) amines, such as ethylenediamine, triethylenetetramine, diethylenetriamine, etc., are most used for room temperature curing. (b) Examples of persulfates and acidic catalysts include potassium persulfate, ammonium persulfate, ammonium chloride, diammonium phosphate, P-toluenesulfonic acid, and amine hydrochloride. In order to form the surface protection layer 3 between the aesthetic side of the acrylic plate 1 on both sides or one side and the coating base material 2 such as a synthetic resin film or sheet, the surface protection layer 3 is formed on the acrylic plate 1 in advance. Apply the pressure-sensitive adhesive composition to this at an appropriate temperature, apply it using a roll (see Figure 3) or other means, and spray it onto the area by spraying it with an appropriate means, and attach the covering base material 2 such as paper to the adhesive composition. to become Alternatively, a layered portion serving as the surface protective layer 3 may be formed on the covering base material 2 such as paper, and this layered portion may be integrally attached to the acrylic plate 1 (see FIG. 4). The aesthetic surface of the acrylic board constructed according to the present invention is protected by a surface protective layer made of the above-mentioned pressure-sensitive adhesive composition, and the outside of the surface protective layer is covered with paper, synthetic resin film, or sheet. Since it forms the base material, the surface protective layer is not exposed and stable adhesive performance can be maintained, which is very suitable.Also, the protective layer is formed between the acrylic plate and the coating base material when they are integrated. Therefore, the cost is low, and the purpose can be fully achieved as an aesthetic surface protection effect. That is, ◎Does not naturally peel off due to changes in time or climate. ◎Stable peel strength and easy peeling. Furthermore, the coating base material and the surface protective layer can be re-adhered to the acrylic plate. ◎Does not contaminate the aesthetic surface of the acrylic board. Next, examples of the present invention will be described in detail below along with comparative examples. Example 1 15 parts of 2-ethylhexyl acrylate, 17 parts of n-butyl acrylate, 4.8 parts of glycidyl methacrylate, and 3.34 parts of methacrylic acid were polymerized in a conventional manner, and ethylenediamine was added to the polymerization composition (40% concentration).
Add 0.9 part with stirring. Then, the above polymer composition is applied to a methacrylic resin plate by the method shown in FIG. 3, and kraft paper is attached and integrated thereon. Example 2 A polymer composition with the same formulation as in Example 1 was applied to kraft paper by a method shown in FIG. Unify. Comparative Example A masking tape (DM made by Daio Kakoshi Kogyo Co., Ltd.) was formed by applying a polymer composition with the same formulation as in Example 1 to kraft paper and drying the polymer composition applied to the kraft paper. −1400)
is pasted on a methacrylic resin board. The results of various tests for Examples 1 and 2 and Comparative Examples are shown in tables below. The symbols in the table indicate the presence or absence of adhesive residue as shown below. 〇…No contamination is observed on the adherend. ○～△: Very slight cloud-like contamination is observed on the adherend. △...A little contamination can be seen with the naked eye on the adherend. (T)...Protective paper lifts. *Note ● Measurement conditions Peeling force unit g/50mm width Peeling speed 300mm/min Peeling angle 180° peeling Humidity pressure test 40℃ x 80% RH x 0.2Kg/m ² Heat resistance pressure test 50℃ x 0.2Kg/m ² Room temperature pressure test 20℃ x 65%RH x 0.2Kg/ ^m2 Sunlight exposure November 1st to 11th, 1978

【table】

[Table] The distinction between 〇, 〇-△, and △ in the above examples is minute, and there is no problem in practical use as masking. As is clear from the table, in the case of Examples 1 and 2, the amount of pressure-sensitive adhesive composition applied to protect the aesthetic surface of the acrylic plate was smaller than that of the comparative example; Adhesive unit price can be significantly reduced. In addition, since it can withstand high temperatures, it can be integrated with the coated base material and formed between the two in the manufacturing process of the methacrylic resin board, which prevents the occurrence of wrinkles, etc. in the coated base material due to increases in board temperature. I got what I could.

[Brief explanation of the drawing]

The figures illustrate embodiments of the present invention. Figure 1 is a cross-sectional view of an acrylic plate with a protective layer formed on both sides, Figure 2 is a cross-sectional view of an acrylic plate with a protective layer formed on one side, and Figure 3 is a cross-sectional view of an acrylic plate with a protective layer formed on one side. 4 are schematic diagrams showing a manufacturing example for the case of FIG. 1. 1...Acrylic plate, 2...Coating base material, 3...Surface protection layer.

Claims (1)

[Claims] 1. Three components (A), (B), and (c) as shown below are emulsion polymerized between both sides or one side of an acrylic board and a covering base material such as paper, synthetic resin film, or sheet. It is formed from an acrylic copolymer resin composition in which an appropriate amount of amines are added as a crosslinking agent to a water-dispersed emulsion, and it is removable from both sides or one side of the acrylic plate together with the coating base material. 1. An acrylic board whose aesthetic surface is protected, characterized in that the acrylic board is formed by integrating a pressure-sensitive adhesive composition as a protective layer with the above-mentioned acrylic board and a covering substrate. (A) Main component monomer (1) Acrylic acid or methacrylic acid alkyl ester having an alkyl group containing 6 to 12 carbon atoms; and (2) Acrylic acid or methacrylic acid alkyl ester having an alkyl group containing 5 or less carbon atoms. Acid alkyl ester (B) Functional monomer (3) N-alkylolamide of acrylic or methacrylic acid (4) Glycidyl acrylate and glycidyl methacrylate (5) Allyl glycidyl ether (c) Functional monomer (6) α-olefin carbon Acids (However, for (3), (4), and (5), use either alone or in an appropriate combination)