JPH0249152B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a decorative sheet useful as flooring material, wall material, furniture material, etc., which has a matted and satin-like uneven pattern on the base material. BACKGROUND ART Conventionally, methods for manufacturing decorative materials in which plastisols and organosols are printed and laminated directly onto base materials such as wallpaper and asbestos paper using rotary screen printing, intaglio printing, etc. are well known. However, decorative materials produced by this general method have poor physical properties, tear or wrinkle during handling or after application, and have poor water absorption and light resistance, so their commercial value is extremely low. It was hot. In order to eliminate this defect, a method has been adopted in which a base coat layer such as vinyl chloride resin is provided on the entire surface of the base material, but the base coat layer must first be free of rips, in other words, be in a matted state. Secondly, it is required to have flame retardancy, and thirdly, it is lightweight. In order to bring the base coat layer close to a faded state, for example, (1) a method of mixing a fade agent or a coarse resin into the sol for the base coat layer. (2) A method of applying an erasing agent to the base coat layer. (3) A method of mechanically embossing the base coat layer. (4) A method of laminating a dot-shaped second layer on the base coat layer. However, the method (1) of adding an erasing agent does not provide sufficient erasing, and when coarse-grained range is included, the coating is difficult to apply in the subsequent process of applying paint and paste sol. In addition, methods (2), (3), and (4) all require mechanical processing equipment and equipment. However, it is inevitable that there are economic disadvantages such as the need for additional steps, increased number of steps, and complexity.
In particular, with the mechanical embossing method (3), when the second layer pattern etc. is laminated and then reheated, the embossment of the base coat layer may flow, which impairs the faded state and also tends to disturb the pattern. Become. As a result of intensive research into a method for manufacturing decorative sheets with reasonable designs without using specific equipment or equipment, the present inventors discovered that the first layer of plastisol or By adjusting the melt viscosity of the organosol to a relatively high value, and melting and foaming the sol after containing a foaming agent, it is possible to obtain a decorative sheet having a brushed surface in a satin pattern with extremely fine irregularities. Furthermore, a plastisol or organosol containing the above-mentioned blowing agent is applied onto a base material, melted at a temperature at which the blowing agent does not decompose, and then solidified. By applying a pattern using a screen or the like and heating and foaming the layer containing the foaming agent, a lightweight and flame-retardant decorative sheet with a clear surface pattern and a clear satin finish on the first layer can be obtained. This discovery led to the completion of the present invention. That is, the object of the present invention is to provide a method for manufacturing a decorative sheet with a finely textured satin pattern by extremely simple operations without using any special equipment or equipment, and in particular a method for producing a decorative sheet with a matte texture pattern. An object of the present invention is to provide a method for manufacturing a decorative sheet having a pattern. Therefore, the gist of the present invention is to provide a method for producing a decorative sheet by coating and laminating plastisol or organosol on a base material and then melting, in which at least the first layer in contact with the base material is a plastisol containing a foaming agent. Alternatively, apply the organosol to the entire surface or part of the base material, melt it at a temperature that does not decompose the blowing agent, solidify the first layer if necessary, and then laminate the second and subsequent layers. The plastisol or organosol containing the foaming agent is foamed by raising the temperature to a temperature at which the foaming agent decomposes, and the plastisol or organosol containing the foaming agent is melted with a composition excluding the foaming agent and diluent under the temperature conditions for melting and foaming. The viscosity
A method for producing a decorative sheet characterized in that the poise is in the range of 3.0×10 ⁴ to 10×10 ⁴ poise. Next, the present invention will be explained in detail. The plastisol used in the method of the present invention is a sol obtained by adding a plasticizer to a so-called vinyl chloride paste range produced by an emulsion polymerization method or a fine suspension polymerization method of vinyl chloride. It is made into a sol by adding a paste sol (hereinafter collectively referred to as paste sol). The diluent is appropriately employed depending on the difficulty of applying the paste sol. In addition to the plasticizer and diluent, various compounding agents such as a filler aid, a pigment, a heat stabilizer, an ultraviolet absorber blowing agent, and a blowing aid may be added to the paste sol. In the method of the present invention, it is necessary to contain a foaming agent and, if necessary, a foaming aid, especially in the first layer of paste sol that directly contacts the base material. , the melt viscosity of paste sol excluding blowing agent and diluent is 3×10 ⁴ to 10×
10 It is necessary to be in the range of ⁴ poise, especially 3×
The range is preferably 10 ⁴ to 8×10 ⁴ poise.
In short, under processing conditions that cause the blowing agent to decompose,
It is necessary that the melt viscosity be adjusted to be within the above-mentioned relatively high range. The diluent is already volatilized under processing conditions that cause the blowing agent to decompose and is essentially absent from the first layer. The paste range blended into the above-mentioned first layer paste sol used in the method of the present invention is not particularly limited, but the average degree of polymerization is 1000 to 1000.
It is preferably in the range 2500, especially in the range 1500-2000. When the average degree of polymerization is lower than 1000, the layer surface tends to become smooth even if the amount of plasticizer is reduced, and the range of processing conditions for forming unevenness tends to become narrow. In this case, a method is adopted in which a blowing agent that decomposes at a lower temperature and, if necessary, a blowing aid (kitsuka) are used, and the blowing temperature is lowered by 10 to 20°C to generate a blowing gas with a high melt viscosity. Furthermore, when a paste range with an average degree of polymerization of 2500 or more is used, the expansion ratio becomes low and an uneven surface with a certain satin pattern is difficult to be formed. As a plasticizer, di(2-ethylhexyl)
Phthalate ester plasticizers such as phthalate (DOP) and butylbenzyl phthalate, aliphatic dibasic acid ester plasticizers such as di-(2-ethylhexyl) adipate (DOA), trimellitic acid ester plasticizers, and polymeric plasticizers. Secondary plasticizers such as epoxy plasticizers, phosphoric acid plasticizers, chlorinated paraffin plasticizers, etc. are appropriately used singly or in combination. The amount of these plasticizers to be used is within the range of 40 to 90 parts by weight per 100 parts by weight of the paste range, and the melt viscosity is 3 × 10 ⁴
Adjust so that the value is higher than Poise. The filler is preferably selected and used as appropriate because it has the ability to stabilize the melt viscosity and eliminate surface cracks. The appropriate amount is usually 30 to 200 parts by weight per 100 parts by weight of paste range, preferably
50 to 130 parts by weight. The filler is selected from inorganic fillers such as calcium carbonate, aluminum hydroxide, and silicates. Furthermore, in a compounding system using a large amount of filler, it is effective to add and mix a surfactant as a means of stabilizing the foam cells. It is preferable to use an appropriate amount of surfactant etc. so as not to excessively lower the interfacial tension.
Effective surfactants include anionic surfactants such as alkyl sulfonates, alkyl ether sulfates, alkyl sulfates, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, sorbitan fatty acid esters, and polyoxyethylene. Examples include nonionic surfactants such as fatty acid esters, higher alcohols, and the like. The blowing agent blended into the paste sol used in the first layer of the method of the present invention is not particularly limited as long as it is a chemical blowing agent that is normally used for foam molding of vinyl chloride resin, but for example, dinitrosopentamethylenetetramine. , azodicarbonamide, azobisisobutyronitrile, P,P'-oxybisbenzenesulfonyl hydrazide, para-toluenesulfonyl hydrazide, benzenesulfonyl hydrazide, etc. It is preferable to use one or a mixture of two or more organic blowing agents. . In the method of the invention, it is particularly preferred to use azodicarbonamide. Although the amount of these blowing agents used varies depending on the amount of gas produced by decomposition during heating, for example, in the case of azodicarbonamide, it is usually appropriate to use 2 to 4 parts by weight per 100 parts by weight of the paste range. If the amount of foaming agent used is small, the formation of surface irregularities will be small, and if it is excessive, gas will escape from the surface, significantly deteriorating the surface appearance. A foaming aid is usually used for these foaming agents in order to lower their decomposition temperature and facilitate foaming. Many foaming aids also have the properties of heat stabilizers, and are useful for heat stability. Specific examples of foaming aids include zinc-based powders such as zinc white,
Sodium-zinc based, barium-zinc based, and calcium-zinc based liquids are used alone or in combination of two or more. If the foaming speed is extremely slow, the formation of irregularities will be small, and if the foaming speed is extremely fast, gas will escape from the surface, so it is desirable to select a combination of foaming agent and auxiliary agent to achieve an appropriate foaming speed. When an organosol is used in the first layer of the method of the present invention, an organic solvent such as methyl cellosolve, ethyl cellosolve, mineral turpentine, mineral spirits, xylene, or toluene is used as the diluent. If the compounding agent added to the plastisol or organosol used in the method of the present invention is a powder, it is preferably mixed into the plastisol or organosol in the form of a toner. In order to make the melt viscosity of the paste sol used for the first layer of the method of the present invention a relatively high value of 3 x 10 ⁴ poise or more, paste range, plasticizer, filler, auxiliary agent, coloring agent, etc. as necessary, etc. The sol is prepared by uniformly mixing the sol with the exception of the blowing agent and diluent. ) and the melt viscosity of the sol is 3×
Confirm that it is within the range of 10 ⁴ to 10×10 ⁴ poise, and then uniformly mix and prepare the required amount of blowing agent or diluent. To carry out the method of the present invention, first, paper, flame retardant paper,
The above-mentioned paste sol is coated and laminated on a base material selected from woven fabrics, knitted fabrics, non-woven fabrics, felt, aluminum foil, etc., the paste sol on the base material is melted, and if necessary, once it has solidified, it is heated again. The temperature is raised to a temperature at which the foaming agent in the paste sol decomposes, and the first layer is formed by foaming, and the surface of the paste sol layer is formed with fine irregularities in a satin pattern. The surface becomes a matte state and becomes an extremely beautiful decorative sheet. In addition, in the method of the present invention, a paste sol is coated and laminated on a base material, the sol layer is melted at a temperature at which the foaming agent does not decompose, and once solidified, the first layer of plastisol or A plastisol with a lower melt viscosity than that is printed in the desired decorative pattern as the second layer using various printing methods, and if necessary, the third layer and subsequent layers are printed and then included in the first layer. The first layer can also be foamed by raising the temperature to the decomposition temperature of the foaming agent. The decorative sheet produced by this method is an extremely beautiful product in which the first layer has a faded surface with a satin pattern and a pattern on the surface. The application of the first layer and the second and subsequent layers of the paste sol does not need to be applied to the entire surface of the base material and the first layer, and may be applied only partially. Further, the decorative sheet may be used by peeling the base material from the decorative sheet depending on the purpose. The method of applying and laminating the paste sol is not particularly limited, and may include ordinary coating methods such as brush coating, knife coating, intaglio or letterpress coating,
Various methods such as rotary screen coating, spray coating, and transfer coating are employed. According to the method of the present invention, by simply adding a foaming agent to a paste sol with a relatively high melt viscosity, applying it onto a base material, melting it, and foaming it, the surface can be erased without using any special machines or equipment. A decorative sheet is obtained, and the paste sol is applied onto the base material and melted at a temperature that does not decompose the blowing agent, then cooled once, and the second and subsequent layers of plastisol are applied to this to allow the blowing agent to decompose. By repeating melting and gelation at high temperatures and then heating to a temperature at which the foaming agent in the first layer decomposes, a decorative sheet with a complex pattern in which the first layer is faded into a satin pattern can be obtained. This is an extremely advantageous manufacturing method industrially. The method of the present invention will be explained in detail below using Examples, but the present invention is not limited to the following Examples unless it exceeds the gist thereof. In addition, "parts" in the examples indicate "parts by weight." Examples 1 to 4, Comparative Examples 1 to 2 (1) Preparation of paste sol (1st layer paste sol formulation) Paste range 100 parts DOP 60 Chlorinated paraffin 10 parts Titanium oxide 10 Azodicarboxylic acid amide 2.2 Na-Ca- Zn-based stabilizer 3 Calcium carbonate 100 Mineral spirit 5 (2nd layer paste sol formulation) Paste range (average degree of polymerization 1200) 100 parts DOP 50 Chlorinated paraffin 5 Titanium oxide 5 Azodicarbonamide 3 Na-Zn-based stabilizer 3 Fine particle calcium carbonate (average particle size 0.08μ fatty acid surface treatment) 5 Mineral spirits 5 In the above first layer paste sol formulation, various paste ranges with different average polymerization degrees () were used.
The foaming agent and diluent were removed, the sol was mixed uniformly, and the melt viscosity of each sol at 195° C. was measured using a capillary rheometer. <Measurement method> Capillary L/D used
= 2.56cm/0.127cm Plunger speed = 0.06cm/min (constant) Shear rate = 3.54sec ^-1 Paste sol 13~15 in a cylinder at 195℃
g and measured for 3-15 minutes, showing the range of melt viscosity (minimum to maximum) during that time. Similar measurements were made for Examples 5 and below. Next, a foaming agent and a diluent were added and mixed uniformly to form a first layer paste sol. The entire amount of the second layer of paste sol was mixed uniformly. Since there was less filler, the melt viscosity was lower than that of the first layer sol without the need for measurement. (2) Manufacture of decorative sheet The first layer of sol was applied onto wallpaper to a thickness of 0.10 mm, melted and gelled in an oven at 110°C for 60 seconds, and then cooled and solidified. Next, a pattern of a second layer of sol was printed on the first layer by rotary screen printing to a coating thickness of about 50 μm. The temperature at which the foaming agent decomposes after printing is 195℃
The foaming ratio of the first layer of the obtained decorative sheet, the quality of the cell structure, and the surface condition of the first layer were observed and evaluated. are listed in Table 1.

[Table] Compounded.
As is clear from Table 1, when the melt viscosity falls within the range of the method of the present invention, an extremely good foam can be produced, and the surface exhibits a satin-like texture with a constant unevenness of about 10 to 20 μm. The base layer is in a completely satisfactorily faded state, and the amount of paste deposited is approximately 210 g/m ² , resulting in an extremely lightweight decorative sheet. Examples 5 to 7, Comparative Examples 3 to 4 The basic composition of the paste sol for the first layer was determined as follows, and the amount of DOP and filler was changed to create the first layer.
Tests were conducted on only the layers and are shown in Table 2. Basic composition Paste range () = 1300) 100 parts DOP 50-70 Dodecylbenzene 5 Calcium carbonate 0-70 Titanium oxide 5 Azodicarbonamide 2.2 Zinc oxide 1.0 Mineral spirits Appropriate amount

【table】

Claims (1)

[Claims] 1. In a method of manufacturing a decorative sheet by coating and laminating a plastisol or organosol on a substrate and then melting it, at least the first layer in contact with the substrate is a plastisol or organosol containing a foaming agent. is applied to the entire surface or part of the base material, melted at a temperature that does not decompose the foaming agent, solidified the first layer as necessary, and then laminated the second and subsequent layers.
Plastisol or organosol, which is formed by foaming by raising the temperature to a temperature at which the foaming agent in the layer decomposes, and which contains the foaming agent, has a composition excluding the foaming agent and diluent under the temperature conditions for melting and foaming. 1. A method for producing a decorative sheet, characterized in that the melt viscosity is in the range of 3.0×10 ⁴ to 10×10 ⁴ poise. 2. The method for producing a decorative sheet according to claim 1, wherein the melt viscosity of the plastisol or organosol in the second and subsequent layers is the same as or lower than that of the first layer.