JPS6220218B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a foam inhibitor to create a foam textured pattern. The present invention relates to the so-called chemical embossing method, and furthermore, the present invention can meet the demands of the era of material saving, and furthermore, the present invention can be applied to a trough that has an extremely large difference in unevenness that would be unbelievable based on the conventional concept of foaming ratio. The present invention relates to a method for producing a foam decorative material having a dyed pattern.

Conventionally, in order to obtain decorative materials that are foamed products, foaming was carried out to a foaming ratio that was just one step before the foamed surface became rough, in order to create the most outstanding three-dimensional and voluminous feel possible.

In addition, many methods using a foam suppressor as in the present invention have been devised, as shown in Japanese Patent Publication No. 47-27994, etc., but when it is desired to further increase the remarkable three-dimensional effect in these conventional methods, The only option was to increase the thickness of the synthetic resin layer containing a foaming agent.

However, increasing the amount of synthetic resin used means increasing the weight of the product, and if this is to be used as wall covering material, the Ministry of Construction has established
In addition to exceeding the weight limit, which is one of the conditions for certification as a legal fire-retardant wall covering material, "wallpaper," it also increases costs, and it is by no means a desirable solution from the standpoint of saving resources, materials, and energy. .

Furthermore, as the thickness of the foaming agent-containing synthetic resin layer was increased, the inhibitory effect of the foaming inhibitor printed on its surface was not sufficiently exerted, and as a result, large foaming irregularities could not be obtained.

By the way, if we consider what the structure of the foam should be in order to obtain noticeable unevenness, we find that
Even if the foam layer that forms the surface layer has a normal expansion ratio, it is desirable that the surface foam layer has a structure in which it is raised upward by the interposition of a large hollow core portion in the height direction. You can say that.

Therefore, as a result of intensive research into how to interpose a large hollow core portion in the height direction, the inventors of the present invention skillfully combined the attributes of conventionally known decomposable foaming agents with foaming suppressants. It was found that the problem could be solved by combining the above, and the present invention was finally completed.

The present invention will be described in detail as follows.

In foaming methods that use blowing agents, decomposable blowing agents are widely used as blowing agents, and decomposable blowing agents include organic blowing agents such as azo compounds, sulfohydrazide compounds, nitroso compounds, and azide compounds. It is well known that inorganic blowing agents have different decomposition temperatures and gas generation amounts.

In general, the decomposition temperature changes greatly when mixed with resins or their raw materials, plasticizers, solvents, stabilizers, acids, bases, etc., and especially when blowing agents are dissolved in compounding agents. For example, azodicarbonamide Two types of decomposable blowing agents have relatively high decomposition temperatures: approximately 200°C for the (ADCA) system, and approximately 130°C for the oxybisbenzenesulfonyl hydrazide (OBSH) system. It is easy to choose.

Therefore, the present invention provides a base material 1 as shown in FIG. 1-A.
A first foaming agent-containing synthetic resin layer 2 is formed on the surface in a desired pattern by, for example, printing and coating, and this is then coated with a second foaming agent-containing layer 2 having a decomposition temperature higher than that of the foaming agent. A material coated with the second synthetic resin layer 3 is obtained, and then, as shown in FIG. A colored or uncolored binder 4 containing a foaming inhibitor is printed only on the surface of the second foaming agent-containing synthetic resin layer 3 that is directly laminated. 4 indicates the colored or uncolored binder printed portion containing the foaming inhibitor.

Next, the product in the state shown in Fig. 1-B was subjected to heating and foaming treatment. In that case, the first layer 2 and the second layer
The foaming of the resin layer of layer 3 reaches completion through the states shown in Fig. 1-C showing the initial stage, Fig. 1-D showing the intermediate stage, and Fig. 1-E showing the final stage, In the end, the surface layer, which is the foamed layer of the second resin, was
While the resin layer 3 still maintains its sealing properties, the first
The hollow core portion 5 is a trace of foaming of the resin layer 2.
3 parts of the second resin layer, which are swollen by the foaming inhibitor, and whose surface is coated with a colored binder containing a foaming inhibitor or a non-colored binder, are hardly foamed due to the effect of the foaming inhibitor, and are foamed unevenly having a valley-dyed pattern. It creates patterns.

Incidentally, in order to obtain the state shown in Fig. 1-B, when printing and coating the first synthetic resin layer 2 containing a foaming agent, the synthetic resin layer 2 should be colored thinly in advance, and the base material should be colored. Marks for pattern matching are printed and coated on both ends of the surface, and the marks for pattern matching are applied when applying the second synthetic resin layer 3 containing a foaming agent.
If a colored or uncolored binder containing a foaming inhibitor is printed in accordance with the mark for pattern matching without being covered, the second synthetic resin layer 2 covering the first foaming agent-containing synthetic resin layer 2 can be printed. The foaming inhibitor is not printed on the surface portion of the layer 3, and the foaming inhibitor does not hinder the growth of the hollow core portion 5 formed by the second foaming agent-containing synthetic resin layer 2.

Next, the steps for forming the hollow core portion 5 will be specifically explained as follows.

At the initial stage of foaming in Figure 1-C, the foaming agent in the first layer 2 has already started to decompose and generate decomposed gas, but the foaming agent in the second layer 3 covering it has not yet started to decompose. Since it has not yet reached the point of decomposition and the state of the sealed membrane is maintained, the decomposed gas from the first layer 2 cannot escape to the outside and pushes the second layer 3 upwards, causing it to swell. I have no choice but to go.

In this process, minute cells are scattered in the first layer 2, but as the foaming progresses, the minute cells grow larger and further, adjacent cells connect with each other, forming the first layer 2.
- It changes into a collection of multiple coarse cells as shown in figure D.

In the state shown in Fig. 1-D, the portion of the second layer 3 where the binder 4 containing the foaming inhibitor is printed does not foam due to the effect of the foaming inhibitor, but the portion of the second layer 3 that covers the first layer 2 does not foam. The foaming of the layer 3 is gradually starting, but not to the point where the cracked gases from the first layer 2 can escape freely, so the above-mentioned push-up continues to grow.

In the final stage of foaming shown in FIG. The layer 3 remains almost unfoamed, but the second layer 3 that covers the first layer 2 is foamed with an appropriate foaming ratio, and the surface is not rough and has a good surface condition. Moreover, since the foamed portion of the second layer 3 has appropriate elasticity, even if a fairly large hollow core portion 5 is formed, the hollow core portion 5 will be held without being crushed. .

In addition, the concentration of the foaming inhibitor mixed in the binder,
Depending on the amount of adhesion, heating conditions, etc., the second layer 3 in the area where the binder 4 containing foam suppressant is printed may foam slightly when reaching the stage shown in Figure 1-E. It does not have enough influence to reduce the difference in level, and since the binder 4 containing the foaming inhibitor is not printed on the surface part of the second layer 3 that covers the first layer 2, the foaming inhibitor will prevent the cavity from forming. As mentioned above, the formation of the core portion 5 is not inhibited.

The size of the hollow core portion 5, which dramatically increases the swelling effect, depends on the amount of decomposed gas from the blowing agent contained in the first layer 2, so the amount of the blowing agent is It may be determined as appropriate in relation to the desired size of the hollow core portion 5. Also the first
If the difference between the decomposition temperatures of the first blowing agent and the second blowing agent is small, there will be no significant deviation in the foaming state of both resins, and the decomposed gas of the first blowing agent inside will not be retained inside and will easily escape to the outside, creating a cavity. Since it becomes impossible to expect much from the swelling effect of the core portion 5, an appropriate difference should be given between the two decomposition temperatures, and the difference should be at least
It is desirable that the temperature is 30℃ or higher.

The first resin can be applied with a printing coating machine such as a screen printer, rotary screen machine, or gravure printing machine, and the second resin can be applied with a coating machine such as a knife coater or roll coater. The synthetic resin contained therein may be formed into a sheet, and this may be laminated onto the base material 1 on which the first resin layer 2 is formed in a pattern.

The binder containing the foaming inhibitor can be printed by a known printing method, but as described above, it is printed in pattern matching with the first layer 2, and the hollow core formed by the first layer 2 is printed. It is important not to inhibit the growth of portion 5.

Further, the binder into which the foaming inhibitor is mixed is usually colored in a desired color, but in some cases, a transparent uncolored binder containing the foaming inhibitor may be used without any problem.

Further, in the case of the method of the present invention, after printing the binder 4 containing a foaming inhibitor on the second layer 3, a transparent protective coating can be further laminated thereon by a known method and then heated and foamed. A material provided with a transparent protective film in this manner can be used not only as a wall covering material but also as a flooring material.

In the present invention, what is referred to as a foaming inhibitor has the effect of hindering the action of a stabilizer that has a foaming promoting effect and is mixed in advance into a foaming agent-containing synthetic resin. When an organozinc compound is used as a stabilizer, the inhibitor is a benzotriazole.

Since this benzotriazole suppresses the effect of the organozinc compound, the decomposition temperature of the blowing agent becomes substantially higher.

In this case, the decomposition temperature of the foaming agent depends on the ratio of the foaming inhibitor to the foaming promoting stabilizer, but by controlling the conditions of the foaming process, the printing ink containing the foaming inhibitor can be printed on the surface. It is also possible to maintain the resin layer in the areas where it is foamed in a state where it is hardly foamed.

There are various combinations of the foam suppressing agent and the foam promoting stabilizer, as shown in Japanese Patent Publication No. 47-27994 mentioned above.

As is clear from the above explanation, the method of the present invention
The first foaming agent-containing synthetic resin layer 2, which is also covered with the second foaming agent-containing synthetic resin layer 3 for forming the surface foam layer, has a different blowing agent decomposition temperature. The first layer 2 is covered by foaming while still maintaining the airtightness of 3, and actively expanding from micro cells to coarse cells and from the coarse cells to a single hollow core portion 5. second layer of part 3
When forming the surface foam layer, the second layer 3 is swollen due to the interposition of the hollow core portion 5, and a binder containing a foaming inhibitor is applied to the surface of the second layer 3, which is laminated directly on the base material. Because it is printed
Since the third part of the second layer forms concave portions without foaming, it is possible to create a foamed decorative material with extremely large unevenness, two to three times as large as that of ordinary foam, without increasing the amount of resin. Moreover, if a colored binder containing a foaming inhibitor is used, the colored portion becomes a concave portion, which is extremely excellent in that a foamed decorative material having a so-called valley dyeing pattern can be obtained.

If the volume of unevenness difference is the same as before,
The method of the present invention has the advantage of requiring about half the amount of materials required, and is much more economical and superior in design than the so-called chemical embossing method that uses conventional foaming inhibitors. You can get something.

The resulting product is also lightweight, soft, and has good insulation properties.
It is extremely excellent in terms of its sound absorbing properties, restoring properties, and buffering properties.

Examples are shown below.

The flow sheet of this example is shown in FIG.

First, the first foaming agent-containing polyvinyl chloride paint shown in recipe A (decomposition temperature of the foaming agent is 130°C) is printed on a wallpaper flame-retardant backing paper 1 with a thickness of about 0.15 mm in a tortoiseshell pattern using a rotary screen machine 6. Coated. 2 shows the coating layer of the first foaming agent-containing polyvinyl chloride paint. The thickness of the coating layer 2 was about 0.04 mm, and the coating amount in m ² was extremely small.

In addition, the first foaming agent-containing polyvinyl chloride paint is colored pale blue to facilitate pattern matching, and when it is printed and coated on the base material using the rotary screen machine 6, it is applied to both ends of the base material. A cross mark for pattern matching was printed and applied regularly.

The backing paper 1 on which the coating layer 2 has been formed is then passed through a drying oven 7 at 120°C for 60 seconds to dry and gel, and then coated with the second foaming agent-containing polyvinyl chloride shown in the recipe B in a knife coater 8. Paint (foaming agent decomposition temperature 200°C) was applied evenly over the entire surface.

3 indicates the coating layer of the second blowing agent-containing polyvinyl chloride paint.

The thickness of the coating layer 3 was a normal coating layer thickness of about 0.15 mm. The backing paper 1 with the coating layer 3 formed on the coating layer 2 in this manner was passed through a drying oven 9 at 120° C. for 90 seconds to dry and gel.

In addition, when laminating the coating layer 3, the cross marks for pattern matching, which are regularly printed on both end surfaces of the base material with the first foaming agent-containing polyvinyl chloride paint, are covered with the coating layer 3. I made sure not to do that.

Next, this is applied to the surface of the second coating layer 3 directly laminated on the base material on which the first coating layer 2 is not formed using the gravure printing machine 10 using the cross marks for pattern matching described above. The printing ink containing a foaming inhibitor colored green was also printed in a hexagonal pattern, and then the printing ink was dried in a drying oven 11.

In this way, the coating layer 3 is formed on the coating layer 2,
Furthermore, the backing paper 1 on which the printing ink containing a foaming inhibitor was printed on the coating layer 3 was subjected to a matte surface treatment according to a conventional method, and then passed through a foaming furnace 12 at 220°C for 60 seconds to undergo first and second foaming. The agent-containing polyvinyl chloride paint was foamed and then cooled in a cooling device 13 to obtain a product.

The resulting product had a very three-dimensional tortoise shell pattern that stood out, and its height was approximately 4 mm.

Moreover, the concave portions were colored green with printing ink, and had a valley-dyed pattern in which the concavo-convex portions and the colored portions were in sync with each other.

The second layer 3, whose surface is printed with the printing ink containing a foaming suppressant from the cut end surface, is hardly foamed, and the other parts are formed with a hollow core, which makes them swell. This was clearly confirmed, and it was found that the two were intertwined to make the unevenness and level difference noticeable.

Note that the foaming inhibitor used in this example was benzotriazole. Moreover, it seems preferable that the amount of the foaming inhibitor mixed into the printing ink is 5 to 25% (weight ratio).

Formulation Table A (parts by weight) PVC 100 parts DOP 70 Stabilizer (Ba-Zn system) 3 Blowing agent (OBSH system) 20 Foaming aid 1 Formulation Table B (parts by weight) PVC 100 parts DOP 28 Flame retardant plasticizer 20 Epoxy plasticizer 2 Stabilizer (Ba-Zn type) 3-part blowing agent (ADCA type) 5 Foam accelerator (organozinc compound) 1.5 Filler 50 Pigment (TiO ₂ ) 20

[Brief explanation of the drawing]

1-A to 1-E are explanatory diagrams from before foaming to after foaming in the method of the present invention, and FIG. 2 is a flow sheet showing the manufacturing process. 1: base material, 2, 3: foaming agent-containing synthetic resin layer,
4: Binder printed part containing foaming inhibitor,
5: Hollow core part.

Claims (1)

[Claims] 1. A first synthetic resin layer containing a blowing agent formed in a pattern on the base material surface is covered with a second synthetic resin layer containing a blowing agent having a decomposition temperature higher than the decomposition temperature of the blowing agent, and then A colored or uncolored binder containing a foaming inhibitor is applied to the surface of the second foaming agent-containing synthetic resin layer portion that is directly coated on the base material surface in the portion where the first foaming agent-containing synthetic resin layer is not formed. is printed, and then heated and foamed to form a foamed surface layer of the second foaming agent-containing synthetic resin layer.
While the resin layer still retains its airtightness, the first resin layer is swollen by the hollow core portion, which is a trace of foaming, and the second resin layer is printed with a colored or non-colored binder containing a foaming inhibitor. A method for producing a foamed decorative agent characterized by forming concave portions without foaming.