JPH0317984B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tile unit temporarily fixed with a specific resin used in precast concrete plates or in constructing concrete structures at construction sites.

Traditionally, tile units have been constructed using paper,
A known method is to attach a tile surface to a sheet-like material such as plywood, a synthetic resin board, or a rubber molded body using an adhesive, and then fix a synthetic resin material to the joints as a temporary joint.

However, in order to prepare a tile unit in this way, there are steps such as first applying adhesive to the sheet material and attaching the tiles, and then forming temporary joints. It requires a lot of labor, and the tiles tend to peel off from the temporary joints due to the lack of adhesive strength.Furthermore, when removing the sheet after the concrete hardens, the adhesive that contaminates the tile surface must be removed. It was necessary, and the process was complicated and the performance was inadequate.

An improved method is to prepare a tile unit by arranging the tiles in a mold with their surfaces facing upward, filling them with thermoplastic adhesive resin, heating and melting them, and then cooling and solidifying them. has been proposed, and this method allows sheets to be formed according to the shape and size of the formwork, compared to the method of placing a resin sheet or foamed resin sheet on the tiles in the formwork and heating and melting it. It has the advantage that there is no need to press it from above with a press or the like, and the processing labor is extremely small.

However, ethylene-vinyl acetate copolymer (EVA) is supplied in the form of pellets, and when filling EVA in the form of pellets according to the above-mentioned improved method, there is a limit to its meltability even if it is heated and melted. However, since the EVA on the tile becomes thick and uneconomical, and there are holes here and there and the tiles are not smooth, it would be better to fill it with powdered EVA, but instead of powdering standard EVA. Therefore, the improved method described above has the disadvantage that it increases the cost considerably.

However, as a result of intensive research, the present inventors have found that a specific ethylene-vinyl acetate copolymer as described later, which is used in the above-mentioned improved method as a thermoplastic resin having adhesive properties, can be mechanically pulverized at room temperature. As described above, the specific EVA powder or the adhesive thermoplastic resin composition containing the specific EVA powder as an essential component can be used. It is possible to avoid the large cost increase caused by freezing and pulverization, and to prepare tile units that have excellent heat meltability and cooling solidification properties during molding, as well as temporary adhesion and rigidity after molding. This discovery led to the completion of the present invention.

That is, the present invention has, as a main component, a vinyl acetate content (hereinafter abbreviated as VA amount) of 5 to 15% by weight, a melt index (hereinafter abbreviated as MI) of 30 to 100, and an ASTM Provides a tile unit temporarily fixed with a powdered resin composition comprising powder of ethylene-vinyl acetate copolymer having a VICAT softening point of 60°C or higher in accordance with D-1525. It is something to do.

Here, the ethylene-vinyl acetate copolymer powder has a VA content of 5 to 15% by weight, which can be powdered by an extremely simple method of mechanical pulverization at room temperature.
, MI is 30 to 100, and Vikatsu softening point is 60℃
This refers to the product obtained by powdering the specific EVA mentioned above.

If EVA with a VA content of less than 5% by weight is used, it will not have temporary adhesion and will be too rigid, making it difficult to peel off after the concrete hardens.
If more than 15% by weight is used, mechanical pulverization at room temperature becomes difficult, so if it is to be carried out more easily and at lower cost, the VA amount should be up to 15% by weight.

In addition, EVA powder with a VA content of 5 to 15% by weight and an MI of less than 30 tends to have poor thermal meltability during molding, resulting in insufficient product shape and adhesive strength, and an MI of 100% or less. If the EVA exceeds 100%, it will not be possible to mechanically crush it at room temperature, and the tensile strength will be too small, making it difficult to peel off the concrete after it hardens.
Undesirable.

Furthermore, the amount of VA is 5 to 15% by weight, and the MI is
Even if it is 30 to 100, EVA with a Vicat softening point of less than 60° C. is not preferable because it cannot be mechanically pulverized at room temperature.

To prepare the tile unit, it goes without saying that the above-mentioned specific EVA powder itself can sufficiently achieve the object of the present invention, but it is also possible to use polyethylene, propylene, polystyrene, or other EVA powder other than the above-mentioned specific EVA powder. Other general purpose EVA
Of course, it can also be used in a form containing a thermoplastic resin having adhesive properties such as.

In addition, if necessary, adhesion promoters such as terpene-based or petroleum resin-based adhesion agents, foaming agents, or fillers may be added to the composition of the present invention to improve the thermal meltability and adhesive strength of the composition of the present invention. may be further improved.

The thus obtained resin composition for temporarily fixing tile units of the present invention is particularly suitable for arranging tiles in a formwork with the tile surfaces facing upward, as described above, and then using a thermoplastic resin composition that is suitable for tiles, etc. Although it is suitable for the method of preparing a tile unit in which the tile unit is filled with adhesive resin and then heated to melt the resin and temporarily bond the tiles, it is simultaneously cooled and solidified, but is not limited to this method. For example, in the resin filling process described above, the composition of the present invention is not only applied to the entire surface of the mold, that is, both the tile surface and the joint frame, but also applied only to the target area. resins other than products, such as pellets
It is also possible to fill EVA, or to fill only the joints with EVA that has been formed into a joint shape, and then fill it with the composition of the present invention. As long as the specific EVA powder mentioned above is used,
It is to be understood that the invention is encompassed by the present invention.

Here, the specific EVA powder, which is an essential component of the composition of the present invention, must have a particle size that does not cause poor product shape (disturbance) caused by pellet-like EVA used in conventional methods. usually less than 2 mm in diameter, preferably
20 meters or less is suitable.

Next, the present invention will be explained in more detail with reference to Examples, and unless otherwise specified, all % means % by weight.

Example 1 Rubber joint frames with vertical and horizontal joint widths of 8 mm and 10 mm, respectively, and a joint depth of 4 mm were installed in a formwork with a length of 420 mm and a width of 580 mm, and then each of these joint frames was Koguchidaira's ``brick tiles'' are placed within the frame.
DR-11'' [porcelain tiles manufactured by Tanto Co., Ltd.] were arranged in a row with their surfaces facing upward.

After that, "Evaflex J-442", which has a VA content of 10%, an MI of 70, and a Vikat softening point of 65°C, is applied to the surfaces and joints of these tiles so that the thickness at the tile surface is 4 mm. ``EVA manufactured by Mitsui Polychemical Co., Ltd.'' was filled with a powder having a diameter of 2 mm obtained by mechanically crushing it at room temperature, and the powder resin was made to have a uniform height.

Next, this mold was heated to 190° C. for 20 minutes to melt the resin, then cooled and solidified, and then removed from the mold to obtain a tile unit.

The tile unit obtained here can be easily melted by heat at the time of manufacture, solidifies quickly by cooling, and is easily demolded.In addition, it has excellent temporary adhesion and moderate rigidity, and is therefore suitable for use with concrete. It was also found that peeling due to the degree of curing is extremely easy.

Example 2 Tiles were arranged in the same manner using the same formwork, rubber joint frame, and tiles as in Example 1, and then pellet-shaped "Sumitate KA-31" was applied to the joints.
[EVA manufactured by Sumitomo Chemical Co., Ltd.; VA amount = 28%, MI =
7. Vikatuto softening point = 38℃] is filled, and then the tile surface is filled with "Sumitate DB-10".
[EVA manufactured by the same company; VA amount = 1%, MI = 70, Vikatsu softening point = 65°C] was mechanically pulverized at room temperature to obtain a powder of 20 to 100 meshes.
10% of the powder of ``100A'' [petroleum resin manufactured by Maruzen Oil Co., Ltd.]
After mixing, the mixture was filled at a uniform height to a thickness of 2 mm.

Next, this formwork was heated to 170℃ as a melting condition.
A tile unit was obtained in the same manner as in Example 1 except that the time was changed to 30 minutes.

The tile unit thus obtained was easy to heat and melt during manufacture, had excellent temporary adhesion, and was also extremely easy to peel off after concrete hardened due to its moderate rigidity.

Claims (1)

[Claims] 1 Powder containing as a main component a powdered ethylene-vinyl acetate copolymer with a vinyl acetate content of 5 to 15% by weight, a melt index of 30 to 100, and a Vikatsu softening point of 60°C or higher. A tile unit characterized by being temporarily fixed with a resin composition.