JP2006187928A - Manufacturing method of foamed polyvinyl chloride wallpaper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for inexpensively manufacturing foamed polyvinyl chloride wallpaper balanced between design properties and fire retardancy at a high level and having good appearance. <P>SOLUTION: The foamed polyvinyl chloride wallpaper is manufactured by a process (1) wherein a composition based on a suspension-polymerized polyvinyl chloride compounded with a foaming agent is laminated on the surface of paper in a thickness of 0.08-0.16 mm by a calender method to form a lower layer, a process (2) wherein a composition based on emulsion-polymerized polyvinyl chloride and compounded with a foaming agent is applied to the surface of the lower layer in a thickness of 0.02-0.06 mm by a coating method to form a surface layer and a process (3) for heating and foaming the lower layer. The composition based on the emulsion-polymerized polyvinyl chloride and compounded with the foaming agent further preferably contains 10-50 pts.mass of calcium carbonate and 5-30 pts.mass of titanium dioxide with respect to 100 pts.mass of polyvinyl chloride. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wallpaper whose surface layer is inexpensive foamed polyvinyl chloride with improved design and flame retardancy. Here, the wallpaper is a decorative material used for a wall or a ceiling as a decorative material for the interior of a building.

Originally, polyvinyl chloride has been used in many fields because it has excellent physical properties, good moldability, becomes flexible by the addition of a plasticizer, has good foamability, and is inexpensive. In the material, a foamed polyvinyl chloride wallpaper having a foamed polyvinyl chloride surface layer and a paper base layer is widely used. A wallpaper in which emulsion-polymerized polyvinyl chloride, so-called paste resin, is coated on paper with a coater, and a wallpaper in which suspension-polymerized polyvinyl chloride, so-called straight resin, is laminated on paper with a calendar are both widely known. A wallpaper using multilayer polyvinyl chloride is also known. A soft polyvinyl chloride film was laminated on a laminate in which soft polyvinyl chloride was laminated on the paper surface by the calendering method, and only the lower layer was foamed (Patent Document 1) or both layers were formed by a coating method. A foamed soft polyvinyl chloride wallpaper (Patent Document 2) has been proposed.
JP 2000-158607 A Japanese Patent Laid-Open No. 9-85921

In recent years, wallpaper with a high level of flame retardancy has been demanded, but the flame retardancy of expanded polyvinyl chloride wallpaper has a strong correlation with the amount of resin per unit area, and the flame retardance decreases as the amount of resin increases. To do. If the amount of resin per unit area is decreased to improve the flame retardancy, the thickness of the foamed resin layer is reduced, and the design properties such as embossability are deteriorated. Therefore, there is a limit to improvement in flame retardancy due to a decrease in the amount of resin per unit area in consideration of design properties. Further, by adding a large amount of a foaming agent and / or inorganic filler to the resin, the embossing property can be improved by increasing the thickness of the foamed resin layer without increasing the amount of resin per unit area. If it is adopted, the surface of the product after foaming is roughened due to a large amount of the foaming agent and / or inorganic filler, and the appearance is deteriorated.
An object of the present invention is to provide a method for producing a low-cost foamed polyvinyl chloride wallpaper that balances design and flame retardancy at a high level and has a good appearance.

  That is, the present invention is as follows: (1) A composition comprising a suspension-polymerized polyvinyl chloride as a main component and a foaming agent is laminated on the surface of paper to a thickness of 0.08 to 0.16 mm by a calendering method. (2) A surface layer is formed on the surface of the lower layer by applying a composition mainly composed of emulsion-polymerized polyvinyl chloride and a foaming agent to a thickness of 0.02 to 0.06 mm by a coating method. (3) A method for producing a foamed polyvinyl chloride wallpaper, which is then heated and foamed. The composition mainly composed of the above-mentioned emulsion-polymerized polyvinyl chloride and containing a foaming agent further contains 10 to 50 parts by mass of calcium carbonate and 5 to 30 parts by mass of titanium dioxide with respect to 100 parts by mass of polyvinyl chloride. Is preferred.

  According to the present invention, an inexpensive expanded polyvinyl chloride wallpaper having good flame retardancy, excellent design, and good appearance can be produced. That is, for wallpaper with a foamed polyvinyl chloride layer on the paper surface, the foamed polyvinyl chloride layer was made into a multilayer and the lower layer was formed by the calendar method using suspension-polymerized polyvinyl chloride. It can be formed stably and inexpensively. In addition, since a surface layer is provided on the lower layer and this surface layer is formed by a coating method using emulsion-polymerized polyvinyl chloride, the surface is not roughened even if the expansion ratio is increased during foaming by heating. , Wallpaper with good appearance can be obtained. Further, since the expansion ratio can be increased, an embossed pattern can be satisfactorily displayed even if the surface layer thickness when not foamed is reduced. Then, the thickness of the lower layer when not foamed is 0.08 to 0.16 mm, the thickness of the surface layer when not foamed is 0.02 to 0.06 mm, and the amount of polyvinyl chloride per area of the wallpaper is reduced. Therefore, flame retardancy can also be maintained.

  In the production method of the present invention, first, a composition comprising a suspension-polymerized polyvinyl chloride as a main component and a foaming agent is laminated on a surface of paper to a thickness of 0.08 to 0.16 mm by a calender method, and a lower layer is formed. Let it form. When laminating polyvinyl chloride containing a foaming agent and / or inorganic filler on paper by the calender method, the laminating process becomes unstable and the thickness unevenness increases, so the thickness of the resin layer is made less than 0.08 mm. It is difficult. Moreover, if it is less than 0.08 mm, it is difficult to sufficiently provide embossing by embossing. Moreover, when it exceeds 0.16 mm, the whole thickness will become thick and a flame retardance will deteriorate. For this reason, the thickness is particularly preferably 0.10 mm to 0.14 mm. Although the lower layer may be two or more layers, even when a small amount of a foaming agent and / or an inorganic filler is blended, the thickness unevenness similarly increases at a thickness of 0.06 mm or less, and the laminating process by the calendar method is unstable. Therefore, forming the two polyvinyl chloride layers by the calendar method makes it difficult to obtain satisfactory flame retardancy because the resin layer becomes thick. Lamination of polyvinyl chloride on paper by the calendar method is performed by a known method.

  In the production method of the present invention, the surface layer is coated by applying a composition mainly composed of emulsion-polymerized polyvinyl chloride and a foaming agent to the surface of the lower layer described above to a thickness of 0.02 to 0.06 mm by a coating method. Let it form. A layer formed by a coating method using a composition mainly composed of emulsion-polymerized polyvinyl chloride and blended with a foaming agent has little surface roughness due to heat foaming. According to the coating method, it is possible to form a thin layer up to about 0.02 mm. However, if the thickness is less than 0.02 mm, the thickness unevenness generated in the upper layer is easily noticeable. When the layer formed by the coating method exceeds 0.06 mm, the thickness of the entire resin layer is increased, and the flame retardancy is deteriorated. Formation of the surface layer by the above coating method is performed by a known coating method such as by a coater. Further, marble printing, gloss adjustment surface treatment, antifouling surface treatment, and the like are performed as desired.

  After the upper layer and the surface layer are formed on the paper surface, the lower layer and the surface layer are foamed by heating with a foaming furnace, a heater or a heating roll to decompose the foaming agent in the lower layer and the surface layer. And it embosses with an embossing roll as needed, winds up to predetermined length, and makes it a wallpaper product. When heating and foaming a wallpaper material that has only one foamable polyvinyl chloride layer on the paper surface, foaming is performed from the outside, so the top of the polyvinyl chloride layer is overfoamed and roughened. The lower part of the foamable polyvinyl chloride layer tends to be insufficient in foaming and does not have an expected expansion ratio. In the method of the present invention, a lower layer is formed on the surface of paper with a composition mainly composed of suspension-polymerized polyvinyl chloride and a foaming agent, and a composition mainly composed of emulsion-polymerized polyvinyl chloride and a foaming agent. Since the surface layer was formed by this, this fear is small.

  The paper used for the production of the wallpaper of the present invention is the paper used for the base material of ordinary wallpaper. Moreover, since the polyvinyl chloride used by this invention attaches importance to foamability, polyvinyl chloride with an average degree of polymerization of about 700-1000 is used. In the present invention, suspension-polymerized polyvinyl chloride is used for the lower layer, and emulsion-polymerized polyvinyl chloride is used for the surface layer, both of which have an average degree of polymerization of about 700 to 1000. As the polyvinyl chloride, a vinyl chloride homopolymer, a copolymer of vinyl chloride and vinyl acetate, a blend of polyvinyl chloride with another polymer, or the like is used.

  In the present invention, a composition comprising a suspension-polymerized polyvinyl chloride as a main component and a foaming agent is used for forming the lower layer. For the formation of the surface layer, a composition mainly composed of emulsion-polymerized polyvinyl chloride and blended with a foaming agent is used. Examples of these foaming agents include pyrolytic azodicarbonamide, 4,4'-oxybis (benzenesulfonylhydrazide), and the like. Moreover, 0.5-7 mass parts is mix | blended with the composition which forms a lower layer with respect to 100 mass parts of suspension polymerization polyvinyl chloride. Moreover, 0.5-7 mass parts is mix | blended with the composition which forms a surface layer with respect to 100 mass parts of emulsion polymerization polyvinyl chloride.

  In addition to the above-mentioned foaming agent, a plasticizer, a stabilizer, a filler and the like are blended in the composition forming the lower layer and the composition forming the surface layer. Examples of the plasticizer include di-isononyl phthalate and dioctyl phthalate. Di-isononyl phthalate is preferably used because the high-boiling plasticizer has little volatilization into room air. A compounding quantity is 45-80 mass parts with respect to 100 mass parts of polyvinyl chloride. Examples of the polyvinyl chloride stabilizer include Ba-Zn metal soaps, epoxy compounds, phosphite triesters, β-diketones, hydrotalcites, zeolites, polyhydric alcohols, and the like. Ba-Zn-based metal soap is preferable because it has a performance as a lubricant for calendering.

  As the filler, a combination of calcium carbonate and titanium dioxide is preferable as a combination of the filler and extender. In the present invention, the lower layer and the surface layer are provided as the foamed polyvinyl chloride layer. However, if the surface layer is given a predetermined color and the lower layer is the same color, the production efficiency is improved. However, in order to carry out this method, it is a necessary condition that the surface layer has high concealability. Therefore, in the present invention, the composition for forming the surface layer includes calcium carbonate having a low concealing property but cheap and having an embossing effect (design improvement effect) by increasing the volume and titanium dioxide having a high concealing property within a specific range. Added. Thereby, the lower layer can be continuously produced with the same color. The surface layer preferably contains 10 to 50 parts by mass of calcium carbonate and 5 to 30 parts by mass of titanium dioxide with respect to 100 parts by mass of the emulsion-polymerized polyvinyl chloride. When the effect of improving the properties is insufficient and the amount exceeds 50 parts by mass, the surface roughness deteriorates. When the amount is less than 5 parts by mass of titanium dioxide, the concealability is insufficient, and when it exceeds 30 parts by mass, surface roughness is deteriorated. The lower layer suspension-polymerized polyvinyl chloride contains 60 to 150 parts by weight of inorganic filler (for example, a mixture of calcium carbonate and titanium dioxide) with respect to 100 parts by weight of polyvinyl chloride, especially 70 to 120 parts by weight. It is preferable to do this.

  A flame retardant is not particularly required. This is because the flame retardancy required by wallpaper (using a cone calorimeter specified by ISO 5660) is a problem of the calorific value during forced combustion, so a flame retardant of a type that delays combustion by blocking oxygen (halogen, phosphorous, etc.) This is because there is no meaning to add an acid ester-based or antimony-based flame retardant. Endothermic flame retardants (magnesium hydroxide, aluminum hydroxide, etc.) are theoretically effective, but not as effective as expected.

  In this invention, you may mix | blend an additive with said each composition further. As antibacterial and antifungal agents, silver-based 10,10'-oxybisphenoxyarsine, 8-oxyquinoline copper, 2- (4-thiazolyl) such as silica gel silver, silver zeolite, zirconium phosphate silver salt, calcium phosphate silver salt -Benzimidazole, methyl 2-benzimidazolecarbamic acid, 2-n-octyl-4-isothiazolyl-3-one, bis (pyridine-2-thiol-1-oxide) zinc salt, 2-peridithiol-1-oxide Sodium salt, N, N ′, N ″ -trishydroxyethylhexahydro-S-triazine, etc. may be blended. In addition, if necessary, foamed cell conditioner, pigment, antistatic agent, ultraviolet absorber, Agents such as deodorants, fungicides, antibacterial agents, insect repellents can be added, pigments, antistatic agents, UV absorption Deodorants, fungicides, antibacterial agents, insect repellents, etc. are effective on the surface, and may be added only to the composition forming the surface layer. The cost can be reduced by adding only to the above.

Examples 1-5, Comparative Examples 1-3
Table 1 is a table showing the compositions of the lower layer composition provided on the paper surface and the surface layer composition provided on the lower layer surface. Table 2 is a table showing the wallpaper manufactured using these compositions and the evaluation of their flame retardancy level, embossable thickness and surface roughness. A is a composition for forming a lower layer, and B-1, B-2 and B-3 are compositions for forming a surface layer.

The wallpaper was manufactured as follows.
(1) Step of forming a lower layer on the surface of paper Add 50 parts by mass of a plasticizer with 2 parts by mass of a stabilizer and 1 part by mass of an acrylic cell regulator, and stir well to create a mixed pack. A composition A was prepared by adding 100 parts by mass of turbid polymerized polyvinyl chloride, 6 parts by mass of a foaming agent, and 70 parts by mass of calcium carbonate, mixing and kneading. This kneaded product was calendered to a thickness shown in Table 2 using a four calender roll having a roll temperature of 160 ° C., and laminated on plain paper for wallpaper having a weight of 65 g / m ² to form a lower layer.
(2) Step of forming a surface layer on the surface of the lower layer To a predetermined amount of plasticizer shown in Table 1, a predetermined amount of stabilizer and acrylic cell conditioner are added, and stirred well to create a mixed pack. Emulsion-polymerized polyvinyl chloride, a foaming agent, calcium carbonate and titanium dioxide were added to and mixed to prepare Composition B-1, Composition B-2 and Composition B-3. These compositions were coated on the surface of each lower layer with a coater at the thickness shown in Table 2 to form a surface layer, and further subjected to gloss adjustment surface treatment.
(3) Heating and foaming process The laminate obtained above was put into a 200 ° C. foaming furnace and foamed, and then embossed with an embossing roller while changing the embossing gap to produce wallpaper.

  In Table 1, PSL-675 (manufactured by Kaneka Chemical Co., Ltd., average polymerization degree 750) was used as the emulsion polymerization polyvinyl chloride. As suspension polymerization polyvinyl chloride, TK-800 (manufactured by Shin-Etsu Chemical Co., Ltd., average polymerization degree 800) was used. Di-isononyl phthalate was used as the plasticizer. The stabilizer used was a 1: 1 mixture of barium stearate and zinc stearate. As the blowing agent, a 1: 1 mixture of azodicarbonamide and 4,4'-oxybisbenzenesulfonylhydrazine was used. As the foam cell regulator, an acrylic cell regulator (300J manufactured by Akishima Chemical Co., Ltd.) was used. NS # 100 manufactured by Nitto Flour Chemical Co., Ltd. was used as calcium carbonate, and NVS-985 (75% by mass of titanium dioxide) manufactured by Nippon Pigment was used as titanium dioxide.

The evaluation of flame retardancy level, embossable thickness and surface roughness shown in Table 2 was according to the following methods.
・ Flame retardance level was based on the weight per unit area of combustible material. In the amount of combustible material (g / m ² ), ◯ indicates less than 161.18, Δ indicates 161.18 or more and less than 263.15, and x indicates 263.15 or more. In the x level, the calorific value of the cone calorimeter test defined by ISO 5660 is approximately 8 J or more, which does not satisfy the requirements for flame retardant wallpaper.
-Thickness which can be embossed shows the maximum thickness of the resin layer in which the deepest trough of an embossing roll contacts a resin layer stably. ○ is more than 1.2 mm, indicating that it has high design properties. Δ is 0.4 mm or more and less than 1.2 mm, indicating a normal design level. X is less than 0.4 mm, indicating that the design is poor.
-The surface roughness was evaluated by visual observation of the surface condition at the part where the embossable thickness was achieved. ○ is good, Δ is slightly rough, and x is clearly rough.

  As can be seen from Table 2, the wallpaper (Comparative Example 3), in which a layer of only the composition A containing a large amount of calcium carbonate (inorganic filler) in the resin is formed on the surface of the paper, has good flame retardancy and embossability. However, the surface is so rough that it does not become a product. The composition A-1, the composition B-2 or the composition B-3, in which the layer of the composition A is a lower layer and the foaming agent is mainly composed of emulsion-polymerized polyvinyl chloride on the surface, is 0.02 to 0. The wallpaper is applied to a thickness of 0.06 mm to form a surface layer. As seen in Examples 1 to 5, the wallpaper has excellent flame retardancy and embossing properties, and has less surface roughness. However, Example 3 which used the composition B-3 which mix | blended calcium carbonate abundantly as the surface layer had a little surface roughness. Moreover, Example 4 which reduced the fabric weight of the lower layer and the surface layer was a little inferior in embossing property. Moreover, Example 5 which increased the fabric weight of a lower layer and a surface layer was a little inferior in flame retardance. When the basis weight of the lower layer and the surface layer is further increased, the flame retardancy is remarkably deteriorated and the product is not commercialized (Comparative Example 1). In addition, the wallpaper (Comparative Example 2) in which a layer of only the composition B-2 is formed on the paper surface has good embossing properties and little surface roughness, but the flame retardancy is extremely inferior and does not become a product.

Claims (2)

  (1) On the surface of paper, a composition composed mainly of suspension-polymerized polyvinyl chloride and containing a foaming agent is laminated to a thickness of 0.08 to 0.16 mm by a calendar method to form a lower layer, (2) On the surface of this lower layer, a composition mainly composed of emulsion-polymerized polyvinyl chloride and blended with a foaming agent is applied to a thickness of 0.02 to 0.06 mm by a coating method to form a surface layer, and (3) heating thereafter A method for producing a foamed polyvinyl chloride wallpaper characterized by foaming. The composition mainly composed of emulsion-polymerized polyvinyl chloride and containing a foaming agent further contains 10 to 50 parts by mass of calcium carbonate and 5 to 30 parts by mass of titanium dioxide with respect to 100 parts by mass of polyvinyl chloride. The method for producing a foamed polyvinyl chloride wallpaper according to claim 1.