JPS588416B2 - Hatsupou Polystyrene Banyou Shiagezai - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to the provision of a finish for expanded polystyrene plates, which are widely employed as insulation materials.

Conventionally, foamed polystyrene plates were finished using cement mortar, inorganic plaster, resin plaster, etc. with a trowel, and the surface was then painted, but these problems tended to cause problems such as peeling and cracking after installation. Improvements are requested.

Regarding the cause of this problem. Difference in rigidity from the base or physical. The current situation is that it is difficult to formulate a policy for requesting a report because the chemical adhesion mechanism is unknown.

Therefore. The inventors of the present invention have theoretically investigated the cause of the occurrence of troubles in reading based on their experience. Based on this, a trial production was conducted and good results were obtained for the finishing material of the present invention.

In other words, although it is not possible to confirm the cause of the difficulty in finishing wet-laid materials on expanded polystyrene plates because the adhesion mechanism to various substrates is still not clear, statistically speaking, it is due to insufficient adhesion. It is thought that there are many things.

Generally speaking, the phenomenon of adhesion of objects is mechanical if we consider adhesion theory roughly. Physical. It is explained that it is the result of chemical forces.

Mechanical adhesion occurs when the adhesive penetrates into the many pores that exist on the surface of the bonded material and hardens. The theory is that the adherends are bonded to each other by so-called anchoring force.

Physical adhesion is explained by the attraction between atoms and molecules, and is currently the most trusted theory.

Chemical adhesion is explained as a primary bond caused by a chemical reaction.

When the above mechanical, physical, and chemical effects occur simultaneously, an extremely strong adhesive force is expected, but in any case, it is an important requirement that the adhesive leaks well from the bonding surface of the adherend. It has become.

The adhesion of wet materials to non-water-absorbing materials such as expanded polystyrene plates can be determined by optimizing the water/binder ratio, as shown in adhesion tests to glass surfaces, which are representative of non-water-absorbing building materials. It can be seen that there is no need to have high expectations regarding mechanical adhesive strength since considerable physical and chemical adhesive strength can be obtained.

However, this phenomenon only occurs when the water/binder ratio is appropriate; on the other hand, if excess water acts on the interface between the wet material and the base, the adhesive strength will be extremely reduced.

Compliant C, an example that was often seen in workshops in the past, is workability (180c) that only considers the workability of plasterers.
Naturally, it is not possible to produce good results if wet-laid materials (around 100 mm) are painted as blanks on expanded polystyrene plates in the same manner as concrete bases.

Especially when using cement mortar, it takes a certain amount of time for the material itself to hydrate and harden. If the coating is too thick and the amount of water is too large, it may slip off due to its own weight.

As mentioned above, the inappropriate water/binder ratio of the wet material is a major hindrance to construction work, but optimizing the water/binder ratio does not immediately lead to improved adhesion, and there is also the possibility that the foamed polystyrene plate and the wet material may not work properly. The problem regarding the difference in stiffness also follows.

In general, if the adherend and adhesive are of different types, residual strain will inevitably occur on the bonded surface due to differences in their physical and chemical properties.

When applying a wet material such as plastic with a trowel to a material with extremely low rigidity that has air bubbles, such as an expanded polystyrene plate, the residual strain may be different in nature, but the strain during construction is added. It becomes like being done.

Furthermore, the total residual strain is expected to increase as the strength of the wet material itself increases.

Currently, among wet materials, plaster blasters for boards are showing relatively good results compared to foamed polystyrene plates.The reason for this is not only because the curing speed is fast and the mechanical adhesion force due to the needle-like crystals can be expected. ．． This is thought to be because the strength of the material itself is low, that is, its rigidity is low, making it difficult to shrink due to drying.

Although it is questionable whether it is possible to arrive at a policy for improving the problem of wet materials for foamed polystyrene plates based solely on the above reasoning. In summary, the properties of wet finishing materials used to coat expanded polystyrene plates. The following conditions can be considered for the finishing method.

(1) Lower the water/binder ratio as much as possible.

(2) The wet material itself has low strength and little shrinkage.

(3) It must be lightweight.

(4) Thin coating thickness.

(5) No stress will be generated on the base during construction.

(6) Mix adhesive into the wet material itself or perform a process to increase adhesion to the base material.

(7) Perform treatment to improve the rigidity of the substrate and obtain mechanical adhesion.

This finishing material was developed with the aim of satisfying the above conditions.

In other words, the composition of the final finishing material is white boltland cement,
Special lightweight aggregate, short asbestos fibers, and 5% of its weight of inorganic pigment. It consists of a 5-10% ethylene vinyl acetate copolymer resin emulsion (solid content 50%) and 75% water.

here. Special lightweight aggregate is an artificial lightweight aggregate that is mainly composed of glassy closed cell granules and is heat resistant. It has excellent properties such as heat insulation. Asbestos short fibers prevent cracks. It is added for the purpose of improving water retention. Ethylene-vinyl acetate copolymer resin emulsion is added as a so-called adhesive, intervening in cement, lightweight aggregate, and short asbestos fibers, and filling the gaps between molecules with its chain molecular structure to make it dense. The bonding and cohesive force improves the adhesion to the foamed polystyrene surface, and the inorganic pigment is added to color the finishing material itself and eliminate the need for surface coating such as paint.

As a result, the finishing material of this composition has low strength and light weight, and by reducing the water/binder ratio or incorporating adhesives and water retention agents, an appropriate adhesive strength and shrinkage reduction effect can be obtained, and the above conditions are satisfied. becomes.

This is finished with a trowel and with a brush. It can be applied directly to the expanded polystyrene plate using a direct finish such as spray finishing.

below. Examples of the present invention are listed below.

Example Preparation of finishing material The finishing material of the above composition was applied to a foamed polystyrene plate with a metal trowel to a thickness of about 5 mm. After being left indoors for 7 and 28 days, the finishing material layer was cut to the surface of the expanded polystyrene plate using a diamond cutter, an iron desk was added, and an adhesion test was conducted using a manual hydraulic testing machine.

(a) Adhesiveness test Adhesive strength (k9/cm2) is expressed as maximum load (kg)/adhesive area (cm2).

The test results are shown in the table below. (1) Setting time (3) Strength (2) Hardness 1 week Hardness 3,2 (Dolomite plaster - JIS standard 4
(E) Special lightweight aggregate The following effects are recognized by implementing the described invention.

(b) In the case of spray finishing, a texture similar to spray tiles can be obtained, and since a plasterer is not required, labor costs are low and the construction period can be shortened.

(100 to 150 m2/3 people per group per day) Also, since construction can be done at the level of a rolling tower, temporary construction costs can be saved.

(Example) Material costs are low, and coloring eliminates the need for surface painting due to the inclusion of pigments.

(・) After painting. No peeling or cracking was observed over a long period of time, reducing problems.

Claims (1)

[Claims] 1 White Bortland cement, special lightweight aggregate, short asbestos fibers, 5% of the weight of inorganic pigment, 5-10% ethylene vinyl acetate copolymer resin emulsion (solid content 50%)
, 75% water.