JP2684046B2 - Adhesive composition - Google Patents

Description

The present invention relates to a pressure-sensitive adhesive composition for temporarily adhering a surface decoration material to a mold or the like when manufacturing a plastic structure integrally having a surface decoration material such as a tile.

Conventionally, for example, when manufacturing a plastic structure such as precast concrete with surface decoration material such as tile, metal,
A surface decoration material such as tiles is fixed in advance to a mold such as wood or plastic with a double-sided adhesive tape or other adhesive, and concrete or other raw material for molding is poured into this, and after solidification, the mold is removed. However, it was difficult to separate the formwork from the formed plastic structure such as precast concrete. For this reason, various measures have been taken, but it takes a lot of time and effort and none is satisfactory.

As a result of various studies on the behavior of the surfactant with respect to the adhesive, the inventors have found that the layer of the adhesive formed by adding the anionic or nonionic surfactant to the hydrophobic acrylic or rubber adhesive It has been found that the adhesive composition has a necessary adhesive force in a normal state, but it swells slightly when it comes into contact with water and the adhesive force decreases, and the adhesive composition is peeled off from the adherend in this state. It is used to temporarily retain the surface decoration material on an adherend such as a mold when manufacturing the attached plastic structure, and the plastic structure can be easily separated from the adherend and the adherend can be easily attached. Further, it was found that the adhesive did not remain on the side of the plastic structure, and it took no trouble to remove the adhesive, and the present invention was accomplished.

The present invention, when producing a plastic structure having a surface decoration material, the surface decoration material as an adhesive composition for temporarily adhering to an adherend, adding a predetermined surfactant to the adhesive component,
It has an adhesive force for stably holding the surface decoration material on the adherend until the plastic compounding raw material is hardened as required, and after the plastic compounding raw material is cured, the adhesive force suddenly decreases when water is contacted. The surface decoration material can be firmly and easily temporarily attached to the surface of the adherend, and does not stick or delaminate stably until the input compounding raw material for plasticizing is cured to the required degree. In addition, when the formed plastic structure is taken out of the mold or the like after the raw material is hardened, it can be easily and quickly removed by pouring water and the like. There is no residue, etc.

The present invention will be described below with reference to examples. The pressure-sensitive adhesives used in the present invention include hydrophobic acrylic and rubber-based pressure-sensitive adhesives, and the acrylic pressure-sensitive adhesives are polymers of acrylic acid ester having 2 to 8 carbon atoms and vinyl acetate, vinylidene chloride, methacrylic acid ester. There are commonly known solvent-type or water-based emulsion type, etc., such as copolymers with vinyl-based monomers such as acrylic acid and methacrylic acid. Also, rubber-based adhesives are mainly natural rubber, synthetic rubber and recycled rubber. Then, a rosin-based resin, a polyterpene resin, or the like is added as a tackifier to the resin.

Nonionic surfactants and anionic surfactants can be used as the surfactants mixed in the pressure-sensitive adhesive component, and the former include polyoxyalkyl ethers, polyoxyethylene alkyl amides, polyoxyethylene alkyl vinyl ethers, polyoxyethylenes. There are alkyl phenyl ethers, polyoxy fatty acid esters, sorbitan fatty acid esters, and the like, and the latter include sodium alkyl sulfates such as sodium polyoxyethylene alkyl ether sulfate, and alkyl allyl sulfonates such as sodium alkyl benzene sulfonate. These surfactants may be used alone or in a suitable amount depending on the composition of the adhesive.
More than one kind can be blended and the blending amount also varies depending on the composition of the adhesive. The pressure-sensitive adhesive obtained from the pressure-sensitive adhesive composition containing a surfactant normally has a pressure-sensitive adhesive force for stably supporting the surface decoration material on the surface of the adherend, and is immersed in the adhesive layer to obtain water in the pressure-sensitive adhesive layer. When it penetrates, it has a characteristic that the adhesive force in the normal state is significantly reduced and the supporting force is lost. That is, since the pressure-sensitive adhesive is hydrophobic and the surfactant mixed therein has both a hydrophobic group and a hydrophilic group, the pressure-sensitive adhesive that is in contact with the surface of the surface decoration material and the adherend is On the surface of the adhesive composition, the hydrophobic group of the surfactant is maintained on the inner side of the pressure-sensitive adhesive composition, and the hydrophilic group is oriented so that the hydrophilic group is positioned on the surface of the pressure-sensitive adhesive composition to maintain the adhesive state. When water is poured into this state, water will gradually penetrate the hydrophilic groups located on the surface of the pressure-sensitive adhesive composition and soak into the surface of the pressure-sensitive adhesive composition. A thin water film comes to be formed at the interface between the surface of the material and the adhesive, the water film gradually spreads, and the adhesive composition comes off from the surface of the surface decoration material. In addition, the pressure-sensitive adhesive composition that adheres to the surface of the mold is the same as in the case of the above surface decoration material. Is presumed to be as peeling in the like, whereby the adhesion state between the mold and the surface decor is solved, it is possible to easily take out the 塑造 structure from the mold,
Moreover, the pressure-sensitive adhesive composition does not remain on the surface of the plastic structure or the surface of the mold. The adhesive force in the normal state of the adhesive composition and the adhesive force reduced by contact with water are, for example, the adhesive force to the steel plate of the double-sided adhesive tape formed as follows using these adhesive compositions (adhesive force in the normal state. ) And this double-sided tape had a reduced adhesive strength when immersed in water for 15 minutes as follows, as shown in Examples.
It is preferably 0 g / 25 mm or more and 100 g / 25 mm or less.

Double-sided adhesive tape: A test adhesive is applied on release paper so that the thickness after drying becomes 50μ, and a non-woven fabric (tissue paper) is stuck on it, and the thickness is applied and formed on the release paper as above. The pressure-sensitive adhesive layer having a thickness of 50 μ was transferred, and the obtained laminated pressure-sensitive adhesive sheet was cut into a double-sided pressure-sensitive adhesive tape having a width of 25 mm.

Adhesion in normal state: 180 ° according to JIS Z1528-1982
Measured by the peeling method.

Adhesive strength after immersion in water for 15 minutes: Stick a double-sided adhesive tape on a steel plate, soak it in distilled water at 23 ° C for 15 minutes, then pull it up and wipe off the adhered water with tissue paper to make an adhesive (exposed ) Surface with polyester adhesive tape (JI
S C2388) is crimped and left for specified time JIS Z-1528−1982
Measured according to (180 ° peeling method).

If the adhesive strength is less than 300 g / 25 mm, it becomes difficult to stably retain the surface decoration material on the mold or the like, which not only requires labor, but also makes it difficult to obtain a plastic structure having a good finish. or
If the adhesive strength after immersion in water for more than 15 minutes exceeds 100 g / 25 mm, it is difficult to cause rapid peeling of the adhesive layer due to water permeation when removing the mold, etc. Contamination is likely to occur on the peeling surface of the body or the plastic structure due to the residual adhesive.

The pressure-sensitive adhesive composition is formed into a pressure-sensitive adhesive by a conventional method,
Tile, brick or other surface decoration material can be used by directly applying it to either surface when it is temporarily attached to an adherend, but the prepared pressure-sensitive adhesive is flexible and has good water content It can be used as a one-sided or double-sided adhesive tape by applying it to one or both sides of paper or other base material by a conventional method to a required thickness. In this case, the tape width, length, etc. can be set arbitrarily, but for example, tape width of about 100 to 500 mm, length of about 30 to
50m, thickness about 0.01-1.10mm formed, the formed adhesive tape is wound around a core or the like via an appropriate separator as required, or formed into a sheet of a required size, and a plurality of these are laminated. And used as appropriate.

 Next, examples of the present invention will be described.

Examples 1 to 26 Each pressure-sensitive adhesive was prepared according to the component composition shown in Table 1, and the characteristics of the double-sided pressure-sensitive adhesive tape formed by each pressure-sensitive adhesive in Table 1 (pressure-sensitive adhesive force, pressure-sensitive adhesive force after immersion in water for 15 minutes, and pressure-sensitive adhesive) The whitening distance of the agent layer), the state of adhesion and holding of the tile by each of the pressure-sensitive adhesives, and the state of peeling of the tile with water are shown.

The method of preparing the pressure-sensitive adhesive, the method for testing each pressure-sensitive adhesive strength and the whitening distance, and the quality of the tile adhesion state and the water peeling state were as follows.

(1) Preparation of pressure-sensitive adhesive Composition of the indicated components (for example, 2-EHA 50g, BA 45g, AA
5g) to polyoxyethylene nonylphenyl ether
Add 1.5g to make a mixture. Ion-exchange water in a three-necked flask (500 ml, stirrer, reflux tube, thermometer, dripping roll)
Add 25 cc and raise the temperature to 85 ° C. with stirring. While maintaining this state, add the mixed solution to obtain a reaction solution. Separately, 25 g of ion-exchanged water containing 1.2 g of ammonium persulfate was prepared, and this was added to the reaction solution in the flask over 5 hours in portions. After the addition, heating and stirring are continued for 3 hours to obtain an emulsion adhesive stock solution. A surfactant (for example, Na salt of polyoxyethylene alkyl ether) shown in the above is added thereto, and stirring is continued for 2 hours to obtain an adhesive stock solution of the present invention. Using this adhesive stock solution, a double-sided adhesive tape was prepared as described above.

(2) The adhesive strength and the adhesive strength after immersion in water for 15 minutes are measured by the above-mentioned method. The whitening distance is based on the following test.

(3) Whitening distance test, affix double-sided adhesive tape to a glass plate, stand it vertically in a dish and double-sided tape is high
Distilled water was added until it was submerged to 1 cm, and the whitening state of the double-sided pressure-sensitive adhesive tape was observed after the temperature was kept at 23 ° C. and left for 24 hours. (A)
Shows the case where whitening occurs above the water surface, the whitening distance is the height (mm) of the whitened portion from the water surface, (B) shows whitening only under the water surface, and (C) shows no whitening.

(4) Adhesion and retention of tiles is good or bad Tile is adhered and retained ++… Stable (400g / 25mm or more), ＋… Stable (400 to 300g / 25mm or more), –… Unstable (300 to 200g / 25mm) , --- No retention (100g / 25mm or less) (5) Peeling condition of tile (Tile peeling condition when a certain amount of water is applied to the held tile) +/- Easy peeling and adhesion No residual agent (10 or more).

+: It peels off easily, but the adhesive may remain slightly (6 to 10 mm).

＋ － ・ ・ ・ Peels off, but a little adhesive remains (1 to 5 mm).

--- Peeled off, but adhesive remains (B).

--- No peeling (C).

(6) Ingredients 2-EHA: 2 Ethylhexyl acrylate BA: n-Butyl acrylate AA: Acrylic acid VAc: Vinyl acetate HEA: 2 Hydroexyl acrylate Comparative Examples 1 to 21 Double-sided pressure-sensitive adhesive tapes similar to those in Examples were prepared except that the composition of the pressure-sensitive adhesives was as shown in Table 2.
Various tests similar to those of the example were carried out, and the results are shown in Table 2.

Claims (1)

(57) [Claims] 1. When manufacturing a plastic structure integrally having a surface decoration material, the surface decoration material is temporarily attached, and the surface decoration material is stabilized until the injected compounding raw material for molding is cured. Characterized by containing an anionic or nonionic surfactant in an acrylic or rubber-based hydrophobic pressure-sensitive adhesive so that it has a holding adhesive force and is easily peeled off by adding water after curing. Adhesive composition.