Recycling method for PVC wallpaper

Abstract

To provide a recycling method for PVC wallpaper that enables the use of collected PVC wallpaper as a recycled raw material efficiently and at a low cost through a simple step, without separating the same into a resin part and a paper part.SOLUTION: A recycling method for PVC wallpaper containing polyvinyl chloride resin, paper, and calcium carbonate comprises: a recovery step of collecting PVC wallpaper manufactured by a specific manufacturer with a known identity; a primary raw material manufacturing step of pulverizing the collected PVC wallpaper to produce a primary raw material; a granule manufacturing step of adding at least polyvinyl chloride resin to the primary raw material to produce a molding raw material granule; a regeneration step of producing a recycled building material using the molding raw material granule; and a reuse step in which the recycled building material is utilized by the specific manufacturer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for recycling PVC wallpaper manufactured by a specific business. [Background technology]

[0002] Wallpaper, which is widely used as an interior material for houses, etc., is composed of resin material, paper (cellulose), and calcium carbonate powder. Among these, wallpaper that uses polyvinyl chloride resin as the resin material (hereinafter sometimes referred to as PVC wallpaper) is a sheet material in which a paper layer and a polyvinyl chloride layer are bonded together, and contains calcium carbonate powder to prevent discoloration.

[0003] Among such PVC wallpapers, wallpaper waste generated during the renovation and demolition of houses, etc., and wallpaper scraps generated during the manufacture and processing of PVC wallpapers are difficult to separate into the paper layer and the vinyl chloride layer, so they have traditionally been disposed of together in landfills or incinerated. However, from the perspective of environmental conservation, it is being considered to use recovered PVC wallpapers as recycled raw materials.

[0004] For example, Patent Document 1 discloses a resin composition for sound insulation sheets that effectively utilizes all components of recovered PVC wallpaper without separating the paper layer, and reuses the resulting sound insulation sheets for homes.

[0005] Furthermore, Patent Document 2 discloses a method for recycling polyvinyl chloride wallpaper, in which waste polyvinyl chloride wallpaper is molded into a recycled sheet without separating the surface material layer made of polyvinyl chloride from the backing material layer made of pulp fibers. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2003-321590 A [Patent Document 2] Patent No. 5936835 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the recycling methods described in Patent Documents 1 and 2 that use PVC wallpaper as a recycled material, many different types of PVC wallpaper manufactured by various businesses are used as recycled material all at once without separating them. As a result, there are issues with the recycled materials having different constituent materials and compositions, such as the need for a complex recycling process to use them as a manufacturing raw material for products other than recycled PVC wallpaper, or to manufacture recycled PVC wallpaper with a uniform material composition, such as separating the resin and paper parts of the collected PVC wallpaper and then determining the composition of the resin part and then adding an optimal amount of virgin resin.

[0008] The present invention has been made in consideration of the above problems, and aims to provide a method for recycling PVC wallpaper which enables PVC wallpaper to be used as a recycled raw material in a simple, efficient and low-cost process without separating the collected PVC wallpaper into a resin portion and a paper portion. [Means for solving the problem]

[0009] The method for recycling vinyl chloride wallpaper of the present invention has the following configuration. (1) A method for recycling PVC wallpaper according to a first aspect of the present invention is a method for recycling PVC wallpaper containing polyvinyl chloride resin, paper, and calcium carbonate, and is characterized by comprising a recovery process for recovering PVC wallpaper manufactured by a specific business operator and whose manufacturer is known; a primary raw material production process for crushing the recovered PVC wallpaper to produce a primary raw material; a granule production process for adding at least polyvinyl chloride resin to the primary raw material to produce molding raw material granules; a recycling process for generating recycled building material using the molding raw material granules; and a reuse process for utilizing the recycled building material by the specific business operator.

[0010] (2) A second aspect of the present invention relates to a method for recycling PVC wallpaper, wherein in the first aspect, the granule manufacturing process adjusts the amount of polyvinyl chloride resin added depending on the type of recycled building material being manufactured.

[0011] (3) A third aspect of the present invention relates to a method for recycling PVC wallpaper, and is characterized in that in the first or second aspect, the recycling step is a step of molding the recycled building material by extrusion molding or calendar molding using the raw material granules.

[0012] (4) A method for recycling PVC wallpaper according to a fourth aspect of the present invention is characterized in that, in any one of the first to third aspects, it further comprises, as a preceding step to the recovery step, an analysis and identification step of analyzing the discarded PVC wallpaper and identifying the manufacturer of the PVC wallpaper.

[0013] (5) A fifth aspect of the present invention relates to a method for recycling PVC wallpaper, and is characterized in that in any one of the first to fourth aspects, the PVC wallpaper recovered in the recovery step is PVC wallpaper used in a building constructed by the specific business operator.

[0014] (6) A sixth aspect of the present invention relates to a method for recycling PVC wallpaper, and is characterized in that, in any one of the first to fifth aspects, the primary raw material contains soft polyvinyl chloride resin, and the molding raw material granules contain hard polyvinyl chloride resin.

[0015] (7) A seventh aspect of the present invention relates to a method for recycling PVC wallpaper, and is characterized in that in any one of the first to sixth aspects, the raw material granules further contain at least one of an impact resistance improver, a processing aid, a light stabilizer, and a heat stabilizer. Effect of the Invention

[0016] According to the present invention, it is possible to provide a method for recycling PVC wallpaper, which can use PVC wallpaper as a recycled raw material in a simple process, efficiently, and at low cost, without separating the collected PVC wallpaper into a resin portion and a paper portion. [Brief description of the drawings]

[0017] [Figure 1] 1 is a flowchart showing a step-by-step method for recycling PVC wallpaper according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, a method for recycling PVC wallpaper according to one embodiment of the present invention will be described with reference to the drawings. Note that the following embodiments are specifically described to better understand the gist of the invention, and do not limit the present invention unless otherwise specified.

[0019] In the following explanation, the term "specific business operator" refers to a business operator (including affiliated companies) that manufactured and sold the PVC wallpaper used as a recycled raw material (hereinafter, for convenience, these will be referred to as Company A), and a business operator (including affiliated companies) that performs construction work using said PVC wallpaper (hereinafter, for convenience, these will be referred to as Company B). Recycled PVC wallpaper refers to PVC wallpaper manufactured and shipped by Company A with a clear manufacturer that has actually been used as wallpaper for homes, etc., and is then peeled off and collected, as well as scraps (cut pieces) that are generated when cutting PVC wallpaper to any size during the manufacture of PVC wallpaper or during construction on homes, etc.

[0020] First, the vinyl chloride wallpaper in the vinyl chloride wallpaper recycling method of this embodiment will be described. The vinyl chloride wallpaper is composed of, for example, a paper layer (paper part) as a base material and a vinyl chloride layer (resin part) covering it, and the ratio of the paper layer is generally 20 to 30 mass % of the entire vinyl chloride wallpaper. The vinyl chloride layer is composed of vinyl chloride resin and calcium carbonate and plasticizers as fillers.

[0021] More specifically, PVC wallpaper should contain, with the total being 100% by mass, 25 to 45% by mass of polyvinyl chloride resin, 15 to 35% by mass of paper, 10 to 50% by mass of calcium carbonate, and 10 to 30% by mass of plasticizer.

[0022] FIG. 1 is a flow chart showing a step-by-step method for recycling PVC wallpaper according to one embodiment of the present invention. The method for recycling PVC wallpaper of this embodiment includes a recovery step S2, a primary raw material manufacturing step S3, a granule manufacturing step S4, a regeneration step S5, and a reuse step S6 in that order, and further includes an analysis and identification step S1 as a step preceding the recovery step S2, as necessary. Among these, at least the primary raw material manufacturing step S3, the granule manufacturing step S4, and the regeneration step S5 are steps carried out by a recycling company contracted with Company B. The recovery step S2 may also be carried out by the above-mentioned recycling company, or by another collection or transport company.

[0023] The analytical identification step S1 is a step for identifying the manufacturer of the PVC wallpaper peeled off from the wall during the renovation, demolition, etc. of the house as a specific business, namely, Company A. If it is clear that the manufacturer of the PVC wallpaper is Company A, such analytical identification step S1 does not need to be carried out.

[0024] The manufacturer of the PVC wallpaper in the analysis and identification step S1 can be determined, for example, from the design, mark, color tone, and manufacturer name written on the back of the PVC wallpaper. It can also be identified by analyzing a part of the resin part of the PVC wallpaper to detect components specific to the PVC wallpaper of Company A. It can also be identified by mixing a specific marker material indicating that the manufacturer is Company A into the resin part during the production of the PVC wallpaper and detecting this marker material.

[0025] The recovery step S2 is a step of recovering PVC wallpaper that is identified as having been manufactured by Company A. The recovery step S2 is performed by a recovery company, for example, an industrial waste disposal company. The recovered PVC wallpaper recovered in this recovery step S2 includes PVC wallpaper manufactured by Company A recovered from buildings, etc., constructed by Company B, PVC wallpaper manufactured by Company A recovered from buildings, etc., constructed by other companies (interior contractors, etc.) than Company B, and identified from construction records, etc., PVC wallpaper manufactured by Company A that is recovered from buildings, etc., constructed by other companies (interior contractors, etc.) than Company B and that can be identified from construction records, etc., scraps discarded when cutting to size during the manufacture of PVC wallpaper manufactured by Company A, scraps discarded when cutting to size during the construction of interiors by Company B or other companies (interior contractors, etc.) than Company B, and PVC wallpaper manufactured by Company A identified in the above-mentioned analysis and identification step S1.

[0026] In such a recovery step S2, only PVC wallpaper identified as manufactured by Company A is selectively recovered as recovered PVC wallpaper, which makes it easier to recycle the PVC wallpaper in a subsequent step.

[0027] The primary raw material production process S3 is a process in which the recovered PVC wallpaper (including scraps) manufactured by Company A recovered in the recovery process is crushed to a size that can be mixed uniformly with the polyvinyl chloride resin to be mixed in the next process. The size of the primary raw material, which is PVC wallpaper after crushing, may be, for example, about 2 to 20 mm, preferably about 3 to 8 mm. A general crusher (crusher, cutter) capable of crushing sheet materials can be used to crush the PVC wallpaper.

[0028] In this primary raw material manufacturing process S3, the recovered PVC wallpaper manufactured by Company A is used as is. In other words, there is no need to physically separate the resin part of the PVC wallpaper from the paper part, or to dissolve the paper part, or perform other pretreatment.

[0029] The PVC wallpaper (primary raw material) crushed in the primary raw material production process S3 should contain, with the total being 100% by mass, 25 to 45% by mass of polyvinyl chloride resin, 15 to 35% by mass of paper, 10 to 50% by mass of calcium carbonate, and 10 to 30% by mass of plasticizer.

[0030] The granule manufacturing process S4 is a process in which the primary raw material formed in the primary raw material manufacturing process S3 is mixed with polyvinyl chloride resin and granulated to form a molding raw material granule. The polyvinyl chloride resin added to the primary raw material here may be, for example, a particulate resin having a particle diameter of about 1 to 20 mm. The polyvinyl chloride resin to be mixed may be either recycled resin or virgin resin. When using recycled resin, it is preferable to select one that is as close to colorless as possible in order to widen the range that can be colored in the subsequent process.

[0031] In addition, the polyvinyl chloride resin added to the primary raw material in the granule manufacturing process S4 contains at least soft polyvinyl chloride resin (S-PVC) and may further be mixed with hard polyvinyl chloride resin (R-PVC).

[0032] In the granule manufacturing process S4, the mixing ratio of the primary raw material and the polyvinyl chloride resin may be any ratio depending on the type (strength, flexibility) of the recycled building material to be produced in the subsequent process using the formed raw material granules, but for example, the mass ratio may be in the range of 3:7 to 9:1. Also, the range of 5:5 to 7:3 is more preferable.

[0033] In addition to polyvinyl chloride resin, it is also preferable to add at least one of the following additives to the primary raw material: impact modifier, processing aid, light stabilizer, and heat stabilizer. These additives can be selected according to the type (strength, flexibility, durability) of the recycled building material to be produced in the subsequent process.

[0034] The mixture obtained by mixing the primary raw material and the polyvinyl chloride resin is then heated to a temperature equal to or higher than the melting temperature of the polyvinyl chloride resin and pelletized to produce the molding raw material granules. The mixture can be granulated, for example, using a melt granulator.

[0035] Thereafter, it is also preferable to further adjust the water absorption rate of the pellet-shaped molding raw material granules formed in the granule manufacturing process S4 so that the water absorption rate is in the range of 0.01% by mass or more and 1.0% by mass or less. When adjusting the water absorption rate of the molding raw material granules, the water absorption rate is preferably 0.5% by mass or less, and more preferably 0.4% by mass or less. When the water content is greater than the above-mentioned range, the water absorption rate of the molding raw material granules can be adjusted by heating the molding raw material granules using an infrared heater or a hot air heater to reduce the water content.

[0036] The recycling step S5 is a step of producing recycled building materials using the raw granules formed in the granule production step S4. Examples of recycled building materials include wall materials, deck materials (floor materials), edging materials, and soundproofing sheet materials for buildings. In the recycling step S5, these recycled building materials are produced by molding the raw granules.

[0037] In this recycling step S5, polyvinyl chloride resin can be added in any ratio depending on the characteristics of the recycled building material to be molded. The polyvinyl chloride resin to be added may be virgin polyvinyl chloride resin or recycled polyvinyl chloride resin. The resin portion of recycled PVC wallpaper can also be used as the recycled polyvinyl chloride resin. The polyvinyl chloride resin is composed of at least soft polyvinyl chloride resin (S-PVC) and rigid polyvinyl chloride resin (R-PVC).

[0038] Examples of molding methods using molding raw material granules include extrusion molding, calendar molding, and injection molding. Among these, extrusion molding involves melting the molding raw material granules and passing them through a die that matches the shape of the recycled building material to be produced. Calendar molding involves softening the molding raw material granules and passing them between a pair of heated rolls to form them into a sheet, which is particularly suitable when the recycled building material is a wall material. Injection molding involves injecting the molten molding raw material granules into a mold that matches the shape of the recycled building material to be produced.

[0039] The reuse process S6 is a process in which the recycled building materials generated in the recycling process S5 are shipped from the recycling business to a specific business, namely Company B, and used by Company B. The use of recycled building materials by Company B includes the application of recycled building materials to buildings and facilities that Company B directly constructs, the application of recycled building materials to buildings and facilities by construction companies commissioned by Company B, and the external sale of recycled building materials under Company B's brand.

[0040] According to the method for recycling PVC wallpaper of the present invention, the recycling company crushes the recovered PVC wallpaper, which is manufactured by a specific company A and has a clear origin, without separating the resin and paper parts, and adds new polyvinyl chloride resin to form a molding raw material granule. The recycling company then uses the molding raw material granule to manufacture recycled building materials in the form required by company B, and delivers the recycled building materials to company B, which then uses the recycled building materials.

[0041] This series of recycling procedures using recovered PVC wallpaper manufactured by a specific business operator makes it possible to recycle PVC wallpaper efficiently and at low cost by streamlining and simplifying the process from recycling recovered PVC wallpaper to molding, compared to the conventional recycling process in which indiscriminately collected PVC wallpaper is separated into resin and paper parts and recycled.

[0042] Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. EXAMPLES

[0043] A specific example of molding a housing-shaped recycled building material using the PVC wallpaper recycling method of the present invention will be described below. The recycled PVC wallpaper used was manufactured by a specific company and had a clearly defined composition: resin layer: 35% by mass, calcium carbonate: 25% by mass, plasticizer (phthalate ester): 15% by mass, paper layer (cellulose): 25% by mass.

[0044] (Verification Example 1) 70% by mass of recycled PVC wallpaper was mixed with 30% by mass of soft polyvinyl chloride resin, and the resulting primary raw material was dried to a water absorption rate of 0.25% by mass. 50% by mass of this dried primary raw material was mixed with 50% by mass of virgin polyvinyl chloride resin, granulated, and dried to a water absorption rate of 0.18% by mass to obtain a molding raw material granule. The raw material granules were used to extrude a housing-shaped recycled building material. The proportion of recycled PVC wallpaper in the entire raw material granules was 35% by mass.

[0045] (Verification Example 2) 70% by mass of recycled PVC wallpaper was mixed with 30% by mass of soft polyvinyl chloride resin, and the resulting primary raw material was dried to a water absorption rate of 0.25% by mass. 65% by mass of this dried primary raw material was mixed with 35% by mass of virgin polyvinyl chloride resin, granulated, and dried to a water absorption rate of 0.20% by mass to obtain a molding raw material granule. The raw material granules were used to extrude recycled building materials in the shape of a housing. The proportion of recycled PVC wallpaper in the entire raw material granules was 46% by mass.

[0046] (Verification Example 3) 70% by mass of recycled PVC wallpaper was mixed with 30% by mass of soft polyvinyl chloride resin, and the resulting primary raw material was dried to a water absorption rate of 0.30% by mass. 35% by mass of this dried primary raw material was mixed with 65% by mass of virgin polyvinyl chloride resin, granulated, and dried to a water absorption rate of 0.16% by mass to obtain a molding raw material granule. The raw material granules were used to extrude a housing-shaped recycled building material. The proportion of recycled PVC wallpaper in the entire raw material granules was 25% by mass.

[0047] (Verification Example 4) 90% by mass of recycled PVC wallpaper was mixed with 10% by mass of soft polyvinyl chloride resin, and the resulting primary raw material was dried to a water absorption rate of 0.30% by mass. 50% by mass of this dried primary raw material was mixed with 50% by mass of virgin polyvinyl chloride resin, granulated, and dried to a water absorption rate of 0.21% by mass to obtain a molding raw material granule. The raw material granules were used to extrude a housing-shaped recycled building material. The proportion of recycled PVC wallpaper in the entire raw material granules was 35% by mass.

[0048] The surface of each of the recycled building materials was observed to check for air bubbles, and visual observations were made after bending tests. "Bubble condition" ◯: no bubbles, △: slight bubbles on the surface. "Bending test results" ◯: No cracks or breaks were observed. △: Slight cracks were observed. These results are summarized in Table 1.

[0049] [Table 1]

[0050] According to the results shown in Table 1, it was confirmed that by using recycled PVC wallpaper manufactured by a specific business, it is possible to produce high-quality recycled building materials with fewer air bubbles and less tearing or ripping, even without separating the resin and paper parts. [Explanation of symbols]

[0051] S1…Analysis specific process S2: Recovery process S3…Primary raw material manufacturing process S4…Granule manufacturing process S5…Regeneration process S6…Reuse process

Claims

1. A method for recycling PVC wallpaper containing polyvinyl chloride resin, paper, and calcium carbonate, comprising the steps of: A collection process for collecting PVC wallpaper manufactured by a specific business operator and whose manufacturer is known; a primary raw material producing step of crushing the recovered PVC wallpaper to produce a primary raw material; A granule manufacturing process in which at least a vinyl chloride resin is added to the primary raw material to manufacture a molding raw material granule; A regeneration step of producing a recycled building material using the molding raw material granules; A recycling process in which the recycled building materials are utilized by the specific business operator; A method for recycling PVC wallpaper, comprising:

2. 2. The method for recycling PVC wallpaper according to claim 1, wherein the amount of polyvinyl chloride resin added in the granule production step is adjusted according to the type of the recycled building material to be produced.

3. 3. The method for recycling PVC wallpaper according to claim 1, wherein the recycling step is a step of molding the recycled building material by extrusion molding or calendar molding using the raw material granules.

4. 3. The method for recycling PVC wallpaper according to claim 1, further comprising an analysis and identification step, which is a step preceding the recovery step, of analyzing the discharged PVC wallpaper and identifying the manufacturer of the PVC wallpaper.

5. 3. The method for recycling PVC wallpaper according to claim 1, wherein the PVC wallpaper collected in the collecting step is PVC wallpaper used in a building constructed by the specific business operator.

6. 3. The method for recycling PVC wallpaper according to claim 1, wherein the primary raw material contains soft polyvinyl chloride resin, and the forming raw material granules contain hard polyvinyl chloride resin.

7. 3. The method for recycling PVC wallpaper according to claim 1, wherein the forming raw material granules further contain at least one of an impact resistance improver, a processing aid, a light stabilizer, and a heat stabilizer.

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