JPS5940224Y2 - laminate board - Google Patents

Description

[Detailed description of the invention] This invention is useful as an interior material for curved surfaces for forming curved wall surfaces in ships, vehicles, houses, etc., or for concrete formwork panels for forming curved surfaces, and is easy to process. The invention relates to laminates.

Conventionally, this type of laminate is a laminate called flexible plywood, which is made by interposing a rubber sheet made of a mixture of natural rubber and synthetic rubber between the front and back veneers, which are arranged with the fiber directions parallel to each other, and then integrating them under heat and pressure. There is a board.

In such a laminate, the fiber directions of the front and back veneers are parallel,
Moreover, since the core material layer is made of a rubber sheet with elasticity, it is easy to bend in the direction perpendicular to the fiber direction, making it easy to form walls with cylinders and other curved surfaces. Because it is used as a wood, it has the disadvantage of producing a large amount of black smoke and toxic gas in the event of a fire.
In addition, the rubber sheet has poor heat resistance and easily peels off when subjected to the continuous boiling adhesive strength test of special grade plywood specified by JAS, resulting in poor durability.

On the other hand, a laminate using a metal plate or a synthetic resin sheet such as PVC or polypropylene as a core material instead of the rubber sheet has been proposed, but when a metal plate is used, the flexibility of the entire laminate is reduced. In laminates using PVC sheets or polypropylene sheets as core materials, it is difficult to apply the required amount of adhesive because the surfaces of these sheets are mirror-like. This makes it difficult to attach the wood to the wood veneer, making it difficult to obtain sufficient adhesive strength.For this reason, the front and back veneers are usually laminated together using an adhesive sheet, etc., but the adhesive strength between the adhesive sheet and the wood veneer is poor. If there is a misalignment between the adhesive layer and the flat plate during bending, or if an adhesive strength test such as repeated boiling or continuous boiling is performed, the adhesive has poor water resistance and will peel off as a whole, making it difficult to maintain sufficient adhesive strength. The disadvantage was that it was difficult to form a laminate.

This invention was made in view of these drawbacks,
Of course, JAS is highly flexible and easy to process curved surfaces.
Laminated boards that pass the repeated boiling and continuous boiling adhesive strength tests stipulated in the standards or have excellent performance equivalent to class 1 plywood and are not likely to emit toxic gases when burned due to fire, etc. It provides:

An embodiment of the present invention will be described with reference to the drawings. The laminate A is a wood veneer 1 made of two rotary veneers of lauan, the front and back of which have fiber directions parallel to each other.

Inorganic fillers such as calcium carbonate are added between 30 and 70 minutes.
% by weight of a thermoplastic synthetic resin sheet 3 such as polyethylene, and bonded the wood veneers 1 and 2 to both the front and back surfaces of the sheet 3 with a water-based vinyl urethane adhesive 4, 4.
The two are bonded to the opposite surfaces of the two and integrally laminated.

In the laminate A constructed in this way, the thermoplastic synthetic resin sheet 3 serving as the core material may be either a stretched sheet or an unstretched sheet of polyethylene, polypropylene, etc., but at least the inside of the sheet 3 is It is necessary to use a material containing 30 to 70 parts by weight of an inorganic filler such as calcium carbonate or titanium oxide.

This is because sheets made solely from synthetic resins such as polyethylene or polypropylene have poor adhesion performance on the sheet surface, and even if they appear to be properly bonded under normal conditions, they easily peel off during continuous boiling tests. By incorporating an inorganic filler such as calcium carbonate into the sheet, a fine rough surface is formed on the surface of the sheet, and the required amount of adhesive can be applied to improve adhesive performance. By reducing the total amount of , heat resistance is improved and the amount of gas generated during combustion is suppressed.

It should be noted that if the content of the inorganic filler is less than 30 parts by weight of the sheet 3, sufficient adhesive performance will not be obtained;
If the amount exceeds the weight part, the flexibility of the sheet will decrease and the curved surface workability of the laminate A will be deteriorated.
It is necessary to use one containing 0 to 70% by weight.

In addition, in the laminate of the present invention, the water-based vinyl urethane adhesive 4, 4 has excellent adhesion to both the wood veneers 1, 2 and the synthetic resin sheet 3, and is heat resistant. It has excellent properties and the adhesive layer after curing is highly flexible so that no cracks occur in the adhesive layer even when processing a curved surface.

Furthermore, since the solvent is water, workability is good and maintenance of the machine is easy.

Next, a thickness of 1 containing 50% by weight of calcium carbonate was prepared.
The laminate A of the present invention is made by laminating 50μ biaxially stretched polypropylene sheets between 2.0m+n thick lauan veneers with their fiber directions parallel to each other via a water-based vinyl urethane adhesive, and an inorganic Contains no fillers15
A comparison table of test results of adhesion performance with laminate B, which was constructed using a 0μ polypropylene sheet and the other conditions were the same as those of the present invention, is shown.

As can be seen from this experimental result, the laminate of the present invention is JAS
It has adhesive strength equivalent to Type 1 structural plywood and bamboo plywood specified in the standard, and is used as a face material for concrete form panels and ships that are easily exposed to harsh usage conditions such as boiling water sterilization. It can be used as an interior base material for vehicles, etc., and is preferable from a safety standpoint since it does not generate a large amount of toxic gas when burned in a fire or the like.

In addition, when implementing the present invention, the front and back wood veneers 1,
When a laminate is formed by laminating and integrating with the synthetic resin sheet 3 with the back cracked surfaces of 2 facing the outer surfaces, the flexibility during curved surface processing is further improved, and a smooth curved surface can be easily formed. preferable.

Further, a suitable decorative sheet may be pasted on the surface of the wood veneer in advance and used as an interior material for forming curved surfaces of houses, vehicles, ships, etc.

As described above, the present invention is a thermo-flexible synthetic resin sheet containing 30 to 70% by weight of an inorganic filler such as calcium carbonate between the front and back wood veneers 1 and 2 whose fiber directions are parallel to each other. 3, and the thermoplastic synthetic resin sheet 3 is integrally bonded to the front and back wood veneers 1 and 2 via the aqueous vinyl urethane adhesive layers 4 and 4. Since the thermoplastic synthetic resin sheet 3 is used as the core material, it can be easily curved into a desired curved surface.Furthermore, this synthetic resin sheet contains 30 to 70% by weight of an inorganic filler, and the sheet and front and back wood veneers 1 and 2
Since these are integrally bonded by the water-based vinyl urethane adhesive layers 4, 4, it is possible to have excellent adhesive strength that meets the JAS standard characteristics or class 1 plywood, as well as durability. It has excellent heat resistance, and unlike conventional laminates that use a rubber sheet as a core material, there is no risk of generating toxic gas when burned in a fire, etc., making it extremely useful as a base material for various interiors and as a base material for decorative laminates. It is something.

[Brief explanation of the drawing]

The drawing is an enlarged longitudinal sectional view showing an embodiment of the present invention. 1.2... Front and back wood veneer, 3... Thermoplastic synthetic resin sheet, 4... Water-based vinyl urethane adhesive layer.

Claims (1)

[Scope of utility model registration request] A thermoplastic synthetic resin sheet 3 containing 30 to 70% by weight of an inorganic filler such as calcium carbonate is interposed between front and back wood veneers 1°2 with fiber directions parallel to each other, and the thermoplastic synthetic resin A laminate formed by integrally bonding the sheet 3 to the front and back wood veneers 1 and 2 via water-based vinyl urethane adhesive layers 4 and 4.