JPS6219774B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention is a foamed decorative material that can meet the demands of the era of material saving, and has extremely large unevenness levels that are unbelievable based on the conventional concept of foaming ratio. This relates to a manufacturing method.

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 foaming surface became rough, in order to create a sense of three-dimensionality and volume as much as possible.

Therefore, in the method of printing a foaming inhibitor as in the present invention, for example, in Japanese Patent Publication No. 46-42637, when it is desired to further increase the remarkable three-dimensional effect, the laminated thickness of the synthetic resin containing the foaming agent is increased. There was nothing else.

However, increasing the amount of synthetic resin used means increasing the weight of the product, and if this is to be used as a wall covering material, it must be used as a legal fire-retardant wall covering "wallpaper" as established by the Ministry of Construction. In addition to exceeding the weight limit, which is one of the certification conditions,
This would increase costs and was not a desirable solution from the standpoint of saving resources, materials, and energy.

Moreover, as the laminated thickness of the synthetic resin containing a foaming agent was increased, the inhibitory effect of the foaming inhibitor printed on the surface was not sufficiently exerted, and as a result, large unevenness levels 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, the inventors of the present invention have conducted intensive research on how to add the above-mentioned large hollow core portion in the height direction. It was found that the problem could be solved by skillful combinations, 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 there are inorganic blowing agents, each with a different decomposition temperature and gas generation amount.

Generally, the decomposition temperature changes greatly when mixed with a resin, plasticizer, solvent, stabilizer, acid, base, etc., and especially when a blowing agent is dissolved in the compounding agent. For example, azodicarbonamide (ADCA) ) system, it is about 200 °C, whereas oxybisbenzenesulfonyl hydrazide (OBSH)
It is easy to select two types of decomposable blowing agents that exhibit relatively high decomposition temperatures, such as about 130°C, in the system.

Therefore, as shown in Figure 1-A, the present invention applies and laminates a first foaming agent-containing synthetic resin layer 2 on one side of the base material using a known method such as a knife coater device. After drying and gelatinizing, the foaming suppressant 3 is printed in a desired pattern using a known printing method such as a gravure printing machine, and after drying, the foaming suppressant 3 is further printed on this using a known printing method such as a knife coater. According to this method, a synthetic resin layer 4 containing a second blowing agent having a decomposition temperature higher than the decomposition temperature of the blowing agent described above was coated, and this layer was further heated and foamed.

Fig. 1-B shows that the foaming inhibitor 3 is printed, and Fig. 1-C shows that the second foaming agent-containing synthetic resin layer 4 is coated thereon. Further, FIG. 2 is an example of a plan view of the state shown in FIG. 1-B, and shows that the foaming suppressant 3 is printed in a pattern.

Then, the product in the state shown in Fig. 1-C was subjected to heating and foaming treatment. At that time, the foaming of the first and second synthetic resin layers is shown in the 1-D stage, which indicates the initial stage.
1-E showing the intermediate stage, and 1-F showing the final stage. While the resin still maintains its airtightness, the first resin layer in the area where the foaming inhibitor is not printed is expanded by the hollow core portion 5, which is the trace of foaming, but each step is explained in detail. A brief explanation is as follows.

First, a first synthetic resin containing a foaming agent is coated and laminated on the base material 1 using a known lamination method, dried and gelled, and then a first synthetic resin layer containing a foaming agent is coated using a known printing method. A foam suppressor is printed on top in a desired pattern and dried. As mentioned above, this stage is shown in FIG. 1-B.

Next, on the first foaming agent-containing synthetic resin layer on which the foaming inhibitor is printed, a second foaming agent having a decomposition temperature higher than that of the first foaming agent is added using a known lamination method. A synthetic resin containing a foaming agent is applied and laminated and dried to form a gel. The first stage shows this stage.
This is diagram C.

Next, when the product obtained in this way is heated and foamed, at the initial stage of foaming shown in Fig. 1-D, the portion where the foaming inhibitor 3 is printed does not change;
First layer of non-printed areas of foam suppressor 2
Although the foaming agent inside has already begun to decompose and generate decomposed gas, the foaming agent inside the second layer 4 that covers it has not yet decomposed, and the state of the sealed membrane remains. is maintained as it is, the decomposed gas from the first layer 2 cannot escape to the outside, and has no choice but to push the second layer 4 upward and swell.

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

At this stage, as mentioned above, the foaming inhibitor 3
The printed area remains almost unchanged due to the effect of the foaming inhibitor.
When the state shown in Fig. 1-E is reached, the second layer 4 laminated on the area where the foam suppressor is not printed gradually begins to foam, but the decomposed gas from the first layer 2 is released freely. Since it has not yet reached the point where it can escape, the above-mentioned push up will continue to grow higher and higher.

At this stage, the portion of the second layer 4 laminated on the printed foam suppressor is maintained in a state where it is hardly foamed due to the effect of the foam suppressant printed below. . In the final stage of foaming shown in FIG. The second layer 4 is foamed with an appropriate expansion ratio, and the surface is not roughened, resulting in a foam with a good surface condition.

Moreover, since the foamed portion of the second layer 4 is a foam having appropriate elasticity, even if a considerably large hollow core portion 5 is formed, the hollow core portion 5 can be held without being crushed. Become.

Note that depending on the concentration of the foaming inhibitor, the amount of printed coating, the heating temperature, etc., when the stage shown in Fig. 1-F is reached, the first layer 2 of the portion where the foaming inhibitor 3 is printed is
The second layer 4, which is the part laminated on top of the printed foam suppressant 3, may foam to some extent depending on the case, but it is necessary to prevent the formation of the hollow core portion 5. Nothing happens. 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. may be appropriately determined in relation to the desired size of the hollow core portion 5. In addition, if the difference in decomposition temperature between the first and second blowing agents is small, there will be little deviation in the foaming states of the two synthetic resins, and the decomposed gas from the first blowing agent will not be retained inside, but will easily leak to the outside. Therefore, the two decomposition temperatures should be given an appropriate difference, and the difference should be at least 30°C.
It is preferable that the temperature is at least ℃.

In the present invention, what is referred to as a foaming inhibitor has the effect of eliminating the action of the foaming accelerator previously mixed into the foaming agent-containing synthetic resin. The foaming accelerator has the role of lowering the decomposition temperature of the foaming agent, and organic zinc compounds are mainly used, and the foaming inhibitors include benzotriazole and the like.

The first and second synthetic resins can be laminated using a known coating machine such as a knife coater or a roll coater. Alternatively, the second synthetic resin containing a foaming agent can be formed into a sheet, and this can be coated with the first synthetic resin. Alternatively, the first and second foaming agent-containing synthetic resins may be formed into sheets, and the first foaming agent-containing synthetic resin After printing the foaming inhibitor in the desired pattern on the resin sheet, or back-printing the foaming inhibitor in the desired pattern on the back side of the second foaming agent-containing synthetic resin sheet, the foaming inhibitor is pasted using a laminator, etc. Multiple layers may be laminated to the base material 1 using a laminating device.

As is clear from the above description, in the method of the present invention, the surface layer is coated with the second foaming agent-containing synthetic resin layer 4 for forming the surface foam layer, and the foaming suppressor 3 is not printed. Due to the difference in blowing agent decomposition temperature, the first foaming agent-containing synthetic resin layer 2 of the section foams while the second layer still maintains its airtightness, and from fine cells to coarse cells, and from coarse cells to single cells. Actively inflate until a hollow core portion 5 of
When the second layer 4 laminated on the area where the foam suppressant is not printed forms a surface foam layer, it is swollen due to the presence of the hollow core portion 5, and the amount of resin is reduced. 2~ of normal foam without increasing
It is extremely superior in that a foamed decorative material can be obtained with an extremely large difference in unevenness, which is three times as large.

If the volume of the unevenness is the same as before, the method of the present invention has the advantage of requiring about half the amount of material required, and is much more effective than the so-called chemical embossing method using a conventional foaming inhibitor. It can be said that this method is economically advantageous and can produce products with excellent design.

The resulting product is also lightweight, soft, and insulating.
It has excellent sound absorption, resilience, and cushioning properties.

Further, in the case of the method of the present invention, after laminating the second layer 4, a transparent protective coating can be further laminated thereon by a known method. 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.

Examples are shown below.

A flow sheet of this example is shown in FIG.

First, a first foaming agent-containing polyvinyl chloride paint 2' (decomposition temperature of the foaming agent 130°C) shown in formulation table A is applied to a wallpaper flame-retardant backing paper 1 with a thickness of about 0.15 mm using a knife coater device 6. The entire surface was coated and laminated uniformly. 2 shows the coating layer of the first foaming agent-containing polyvinyl chloride paint 2'. The thickness of the coating layer 2 is approximately 0.06
mm.

The backing paper 1 on which the coating layer 2 has been formed is then heated to 120°C.
After passing it through a drying oven 7 for 60 seconds to dry and gel it, the foam suppressant 3 is printed in a fine circular pattern as shown in FIG. 2 using a gravure printing machine 8 or other known printing device. , foaming suppressant 3 in drying oven 9
is dried, and then a knife coater device 10 is applied on this.
The second blowing agent-containing polyvinyl chloride paint 4' (decomposition temperature of the blowing agent: 200°C) shown in Formulation Table B was uniformly applied and laminated over the entire surface.

4 indicates the coating layer of the second blowing agent-containing polyvinyl chloride paint 4'. The thickness of the coating layer 4 was approximately 0.10 mm.

In this way, the backing paper 1 on which the coating layer 4 was formed is
The first and second blowing agent-containing polyvinyl chloride paints were passed through a drying oven 11 at 120°C for 80 seconds to dry and gel, and then passed through a foaming oven 12 at about 220°C for 60 seconds to form the first and second foaming agent-containing polyvinyl chloride paints as described above. The foam was sequentially foamed according to the foaming process, and then cooled in a cooling device 13 to obtain a foamed decorative material.

In the resulting product, the circular portion where the foam inhibitor was not printed was foamed in the shape of a dewdrop, and the height of the foam was approximately 4 mm. A hollow core portion is formed from the cut end surface,
This clearly confirmed that it was gaining momentum.

Formula A (parts are parts by weight) PVC 100 parts DOP 70 parts Stabilizer (Ba-Zn type) 3 parts Foaming agent (OBSH type) 20 parts Foam accelerator 1.5 parts Mixture Table B (parts by weight) PVC 100 parts DOP 28 parts Flame retardant plasticizer 20 parts Epoxy plasticizer 2 parts Stabilizer (Ba-Zn type) 3 parts Blowing agent (ADCA type) 5 parts Foam accelerator 1.5 parts Filler 50 parts Pigment (titanium oxide) 20 parts In addition, Figure 3-A, Figure 3-B, and Figure 3-C show the conventional so-called chemical embossing method.
42637 etc., the state in which the foaming agent-containing synthetic resin layer 4 is laminated on the base material 1, the state in which the foaming inhibitor 3 is printed on it, and the state in which this is foamed and raised are cut in order. The end face is shown to clarify the difference from the present invention.

[Brief explanation of the drawing]

Figure 1-A, Figure 1-B, Figure 1-C, Figure 1-
FIG. D, FIG. 1-E, and FIG. 1-F are enlarged sectional views at each stage obtained by the present invention. FIG. 2 is a perspective view of a product obtained by the present invention. 3-A, 3-B, and 3-C are enlarged sectional views at each stage obtained by the conventional method. FIG. 4 is a process diagram for implementing the present invention. 1: base material, 2: first foaming agent-containing synthetic resin layer,
2': The paint, 3: Foaming inhibitor, 4: Second foaming agent-containing synthetic resin layer, 4': The paint, 5: Hollow core portion, 6, 10: Knife coater device, 7,
9, 11: Drying oven, 8: Gravure printing machine, 12:
Foaming furnace, 13: Cooling device.

Claims (1)

[Claims] 1. After laminating a first foaming agent-containing synthetic resin layer on the base material surface and printing a foaming inhibitor in a desired pattern on the synthetic resin layer, this is further heated to a temperature higher than the decomposition temperature of the foaming agent. A second synthetic resin layer containing a blowing agent having a decomposition temperature is coated, and then this is foamed, and the surface layer of the second synthetic resin layer containing a blowing agent is coated with a second synthetic resin layer. A foamed decoration characterized in that, while the layer still maintains its airtightness, the first synthetic resin layer in the area where the foaming inhibitor is not printed is swollen by a hollow core portion that is a trace of foaming. Method of manufacturing wood.