JPH0240711B2 - GOSEIJUSHIITAYOHYOMENHOGOZAI - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a surface protection material for synthetic resin plates. Traditionally, synthetic resin boards have been prone to scratches on their surfaces, and dust and chips from shearing tend to adhere to them during pressurization, transportation, storage, etc., so in order to protect the surfaces of synthetic resin boards, Various surface protection materials have been proposed and used. For example, kraft paper
There is a protective material that uses a synthetic resin film as a base material and adheres it to a synthetic resin plate using a synthetic resin-based or rubber-based pressure-sensitive adhesive. However, the above-mentioned conventional pressure-sensitive type protective materials are not only expensive, but also have too strong adhesion to synthetic resin plates and tend to deteriorate over time. In addition, extrusion molding has recently been widely adopted as a molding method for manufacturing synthetic resin boards, so extruded resin boards (methacrylic acid, polycarbonate boards,
When using the above conventional pressure-sensitive type protective materials for polyvinyl chloride plates, polystyrene plates), the current situation is that the plate temperature causes floating wrinkles, etc., and it does not fulfill its role as a protective material. . This is because the temperature of the synthetic resin board on the extrusion molding line ranges from 20°C to 100°C. For example, if a sensitive type surface protection material is applied at 100°C, paper or film may be used as the base material. If the protective material is used, it will become floating, and during shearing, chips from the synthetic resin board will get into the space between the floating protective material and the synthetic resin board, causing surface flaws.
On the other hand, in areas where the adhesive was too strong, it was found that the adhesive could not be peeled off, which caused problems when attempting to print a trademark or the like on the board surface by peeling off a portion of the surface protective material. Pressure-sensitive protective materials based on paper or film have a plate temperature limit of 60°C, and self-adhesive film protective materials are difficult to peel off from synthetic resin plates with high plate temperatures. Changes occur over time when left outdoors. Furthermore, some surface protection materials are made of paper or film as a base material and have a wet-type adhesive layer formed thereon, but conventional products are not suitable for extrusion-molded synthetic resin plates with high plate temperatures on the molding line. It was difficult to use because it could not adapt to board temperature and line speed for consistent adhesion. Therefore, the present invention aims to provide a water-applying type surface protection material that also has the re-adhesive property that is a characteristic of a pressure-sensitive type.
Its composition is as shown below on one side of the paper base material.
It is characterized by forming an adhesive layer composed mainly of a water-soluble acrylic resin consisting of three components (1) to (3). (1) Acrylic acid or methacrylic acid alkyl ester having an alkyl group containing 6 to 12 carbon atoms with a monomer content of 20 to 80% (2) Acrylic acid or methacrylic acid having an alkyl group containing 5 or less carbon atoms Monomer ratio of 20 to 80% with alkyl ester (3) Monomer ratio with acrylic acid or methacrylic acid alkyl ester having a nitrogen-containing alkyl group
10 to 50% Furthermore, in order to further stabilize the adhesive layer, the present invention is characterized in that a coating layer made of a polyolefin resin is formed on the other surface of the base material in the above structure. Next, to explain the surface protection material of the present invention in detail, in FIG. 1 (FIG. 2) of the attached drawings, 10 is a base material made of paper such as kraft paper, and 20 is an adhesive formed on one side of the base material 1. The main component is a water-soluble acrylic resin (80-99% by weight), and a small amount of a softening agent (0-10% by weight) and an antifoaming agent (0.01-0.1% by weight). Then, moisture is added to this adhesive layer 20 by steam or water spray, and the adhesive layer 20 is dissolved and attached to the synthetic resin plate P. According to the adhesive layer 20, even after moisture has been dispersed after use, adhesiveness is imparted to the adhesive layer 20, and it has a moderate adhesiveness that does not cause floating wrinkles, peeling, etc. even on a synthetic resin board with a high board temperature. It maintains a stable adhesion due to its adhesive properties. In other words, if the adhesiveness disappears, floating wrinkles and peeling will often occur on high-temperature plates, and if the adhesiveness is too strong, the problem of being unable to peel will occur, but the surface protection material of this invention No such phenomenon has been observed. Furthermore, in FIG. 3 (FIG. 4), 30 is a coating layer made of polyolefin resin formed on the other surface of the base material 10 opposite to the adhesive layer 20,
When the coating layer 30 is formed, it has a large effect of suppressing moisture evaporation in the adhesive layer 20 and also has an effect of controlling moisture from the outside air, thereby making the adhesive layer 20 more stable. That is, by forming the coating layer 30 as a surface protection material, the adhesion state of the adhesive layer 20 to the synthetic resin plate P can be more stabilized, and the occurrence of floating wrinkles can be more reliably prevented. Next, regarding the water-soluble acrylic resin which is the main component of the adhesive layer 20 described above, (1) acrylic acid or methacrylic acid alkyl ester having an alkyl group containing 6 to 12 carbon atoms with a monomer ratio of 20 to 80; % (2) Monomer ratio of acrylic acid or methacrylic acid alkyl ester having an alkyl group containing 5 or less carbon atoms with a monomer ratio of 20 to 80% (3) Acrylic acid or methacrylic acid alkyl ester having an alkyl group containing a nitrogen-containing compound It consists of three components (1), (2), and (3) with a monomer ratio of 10 to 50% and is solution polymerized. That is, the water-soluble acrylic resin is composed of the following polymerization. [Parts by weight] 2-Ethylhexyl acrylate 60 parts Methyl acrylate 94 parts Dimethylaminoethyl methacrylate 46 parts Azobisisobutyl nitrile 1.5 parts Isopropyl alcohol 17 parts Isopropyl alcohol 180 parts Azobisisobutyl nitrile 0.2 parts Water 577 parts Celloacetate 12.8 parts These polymerizations It is carried out at the boiling point of isopropyl alcohol. After the solvent is diffused and celloacetate is added, a water-soluble resin is obtained. Regarding the monomer blending ratio, polymerization is initiated in a solvent in the same manner as in normal solution polymerization. As the initiator, commonly used benzoyl peroxide, azobisisobutylnitrile, etc. are used, and as the solvent, in addition to toluene, ethyl acetate, xylene, etc., isopyropyl alcohol is generally used. Ethyl cellosolve oxide acetate (hereinafter referred to as celloacetate), butyl oxide, etc., which are water-soluble, are added to these, the solvent is evaporated, and water is added to make them water-soluble. As a specific example of the manufacturing recipe, it may be arbitrarily changed within the above-mentioned range. The proportions below are used for formulations with adhesive properties. For this formulation, softener,
Antifoam is added. In particular, as softening agents, ethylene oxide, propylene oxide derivatives, glycerin, etc. are used. [Weight ratio] Water-soluble acrylic resin (10-30%) 80-99% Polyethylene glycol (number of moles added: 200-30%)
20000) 0 to 10% Antifoaming agent 0.01 to 0.1% Next, when considering moisture permeability as one point, the moisture permeability of the polyolefin resin of the coating layer 30 formed on the other side of the base material is as follows: Polyethylene resin For polypropylene resin: 60g/m ²・24hr For polypropylene resin: 55g/m ²・24hr However, for polyethylene resin and polypropylene resin, laminate 40g/m ² cardboard with a thickness of 15μ on kraft paper. The features of the surface protection material according to the present invention described above are (1) It can be bonded to synthetic resin plates (methacrylic plates, polycarbonate plates, vinyl chloride plates, polyethylene plates, etc.) even when the plate temperature is 100°C or higher. . (2) Conventional surface protection materials tend to raise and wrinkle due to plate temperature, so in the case of extruded plates, the application speed is slowed down or the plate is cooled using a cooling (plate temperature cooling) device. In the case of this invention, the speed of the bonding work can be increased without being affected by the plate temperature. (3) Synthetic resin plates are usually heat-formed, and preliminary drying may be required for heat-forming. For polycarbonate plates, it may take several hours at 120 to 130℃, but with conventional products, if the surface protection material was left attached, it would fall off during drying or be impossible to remove after drying, but this invention In the case of , all of these problems are solved and the board surface is reliably protected. (4) In the case of this invention, as mentioned above, there is no floating wrinkles, so even if shearing is performed with the surface protection material attached, there is no risk of chips entering between the surface protection material and the synthetic resin board. . (5) In the case of the present invention, although it is a water-applying type, it has a property that it can be re-attached even if it is partially peeled off for printing or the like after the surface protection material is attached. (6) In the case of the invention in which a polyolefin resin coating layer is formed on the other side of the paper base material, the influence on plate temperature is further reduced, and the protective functionality of the surface protection material is maintained better. Next, examples of the present invention will be described in detail below along with comparative examples. In practice, a polyolefin resin is laminated on one side (rough side) of 40 g/m ² single gloss kraft paper, and the base material surface (glossy side) is coated with each adhesive to serve as a surface protection material. After drying, a surface protection material was bonded to the synthetic resin board by spraying water or steam, and the adhesive strength, re-adhesion, weather resistance, adhesive residue on the board surface after peeling, etc. were tested. Example 1 Water-soluble acrylic resin 95g Polyethylene glycol #200 (added mole 200)
5g NOPCO 8034 0.1g Example 2 Water-soluble acrylic resin 93g Polyethylene glycol #1000 (added mole 1000)
7g NOPCO 8034 0.1g Example 3 Water-soluble acrylic resin 100g NOPCO 8034 0.1g Comparative example 1 Polyvinyl alcohol GL-05 95g Polyethylene glycol #200 (number of moles added 200)
5g NOPCO 8034 0.1g Comparative Example 2 Polyvinyl Alcohol GL-05 50g Polyvinyl Alcohol GH-17 45g Glycerin 5g NOPCO 8034 0.1g *The above water-soluble resin concentration is 20%. Polyvinyl alcohol GL-05 Polyvinyl alcohol GH-17 15% concentration Polyethylene glycol #200, #1000 Glycerin 100% concentration NOPCO 8034 (mineral oil) is a trade name of Nobuco Company.

【table】

[Table] The above examples are for a surface protection material (described in claim 4) in which an adhesive layer is formed on one side of the base material and a coating layer made of polyolefin resin is formed on the other side. However, a surface protection material that does not have a coating layer (as described in claim 1)
When the test was carried out under the same conditions, it was found that the adhesion strength, adhesion strength over time, and re-adhesion strength were lower than those in the previous table by a slight difference that did not affect the achievement of the purpose of the invention. *Note: ΓAdhesion measurement conditions: Measure after standing for 20 hours under 20℃ x 60%RH conditions. Adhesive force unit g/100mm width Peeling speed 300mm/min Peeling angle 180 pilling Γ Adhesive strength over time Γ Adhesive strength after being left for 90 days under 20°C x 60% RH conditions Γ Weather resistance Adhesive strength Γ after 200 hours of irradiation with a weatherometer Adhesive Residue 〇…No adhesive residue is observed (no visible glue remains on the synthetic resin board) ×…Adhesive residue is observed (no visible glue remains on the synthetic resin board) −…Adhesion strength cannot be measured in a floating state /…When the synthetic resin board itself is not suitable for the pre-drying conditions of 120℃ x 4 hours before molding processing

[Brief explanation of drawings]

The figure illustrates an embodiment of the invention, the first
The figure is a cross-sectional view, Figure 2 is a cross-sectional view of the previous figure when it is in use, Figure 3 is a cross-sectional view when there is a coating layer made of olefin resin, and Figure 4 is a cross-sectional view of the previous figure when it is in use. . 10...Base material, 20...Adhesive layer, 30...Coating layer, P...Synthetic resin plate.

Claims (1)

[Scope of Claims] 1. An adhesive layer composed mainly of a water-soluble acrylic resin consisting of the following three components (1) to (3) is formed on one side of a paper base material. A surface protection material for synthetic resin boards characterized by: (1) Acrylic acid or methacrylic acid alkyl ester having an alkyl group containing 6 to 12 carbon atoms with a monomer content of 20 to 80% (2) Acrylic acid or methacrylic acid having an alkyl group containing 5 or less carbon atoms Monomer ratio of 20 to 80% with alkyl ester (3) Monomer ratio with acrylic acid or methacrylic acid alkyl ester having a nitrogen-containing alkyl group
10 to 50% 2 The surface protection for a synthetic resin board according to claim 1 above, wherein a small amount of a softening agent and an antifoaming agent are added to the adhesive layer mainly composed of a water-soluble acrylic resin. Material. 3. An adhesive layer composed mainly of a water-soluble acrylic resin consisting of three components (1) to (3) as shown below is formed on one side of a paper base material, and a polyolefin-based adhesive layer is formed on the other side of the base material. A surface protection material for synthetic resin boards, characterized by forming a coating layer of resin. (1) Acrylic acid or methacrylic acid alkyl ester having an alkyl group containing 6 to 12 carbon atoms with a monomer content of 20 to 80% (2) Acrylic acid or methacrylic acid having an alkyl group containing 5 or less carbon atoms Monomer ratio of 20 to 80% with alkyl ester (3) Monomer ratio with acrylic acid or methacrylic acid alkyl ester having a nitrogen-containing alkyl group
10 to 50% 4. The surface protection material for a synthetic resin board according to claim 3, wherein the polyolefin resin layer is a polyethylene resin layer. 5. The surface protection material for a synthetic resin board according to claim 3, wherein the polyolefin resin layer is a polypropylene resin layer.