JP4770182B2 - Disassembly method of artificial marble - Google Patents

Description

  The present invention relates to an artificial marble used as a building material including bathroom materials, kitchen counter materials, furniture materials, interior materials, exterior materials, and the like, and in particular, a decomposition method for recovering valuable materials from waste artificial marble. It is about.

Conventionally, most plastic waste containing artificial marble has been landfilled or incinerated, and has not been effectively utilized as a resource. In addition, landfill disposal has problems such as difficulty in securing a landfill site and instability of the ground after landfilling, and incineration treatment has problems such as furnace damage, generation of harmful gases and odors, and CO ₂ emissions. For this reason, in accordance with the Law for Promotion of Effective Utilization of Resources in April 2001, various recycling laws such as bathroom units that use a lot of plastic and artificial marble, and system kitchens are designated as specific reuse promotion products. The trend toward collection and recycling of plastic products including artificial marble tends to accelerate.

  In recent years, attempts have been made to recycle plastic waste in accordance with these situations, and as one of them, plastic waste is decomposed into oil by a reaction using supercritical water as a reaction medium. Methods for recovering oily substances have been proposed, and for fiber reinforced plastics used in various structural materials, resin components are decomposed using supercritical water or subcritical water, and glass fibers, carbon fibers, etc. A method of collecting and reusing fibers has been proposed (see, for example, Patent Documents 1-5).

  In these methods, a monomer component as a raw material can be recovered if the resin is a resin such as a polyester resin that contains many ester bonds that are susceptible to hydrolysis. However, in the case of artificial marble thermosetting resins represented by vinyl ester resins, there are very few ester bonds, and the resin component is randomly reduced in molecular weight by thermal decomposition to become an oily component consisting of various components. It will be reused as liquid fuel. For this reason, post-treatment such as reforming oil quality using a catalyst typified by zeolite is required, resulting in high costs, and even in the reformed product oil, petroleum products such as kerosene and light oil itself Since it is difficult to achieve this, it has not been put into practical use.

Considering the problems of the entire global environment such as the depletion of petroleum resources and global warming due to carbon dioxide, it is necessary to take drastic measures to disassemble and reuse artificial marble containing thermosetting resins. .
JP-A-10-237215 JP-A-8-85736 JP 2000-53801 A JP 2000-61423 A JP 2001-170603 A

  The present invention eliminates the problems of the prior art from the background described above, and can decompose artificial marble so that both inorganic fillers and thermosetting resins can be reused as raw materials for artificial marble. Therefore, it is an object to provide a new method for decomposing artificial marble.

  The method for decomposing artificial marble of the present invention is characterized by the following as a solution to the above problems.

First: containing mainly an inorganic filler and a thermosetting resin, the inorganic filler is aluminum hydroxide vinyl ester artificial marble wherein the thermosetting resin is a vinyl ester resin, of 180 ° C. ~ 280 ° C. It is treated with subcritical water in the temperature range, and this subcritical water treated product is subjected to solid-liquid separation to thereby separate a water-soluble component containing a valuable polymer material derived from the thermosetting resin and a material derived from the inorganic filler. -Collect solid residue containing mitite to obtain valuable materials that can be reused as raw materials.

Second : Alkaline coexists in subcritical water .

Third : The coexisting alkali is at least one of Group 1A (alkali metal), Group 2A (alkaline earth metal), and basic phosphate.

According to the first invention as described above, simple and convenient, and efficient artificial marble, the inorganic filler, both thermosetting resin, is it possible to decompose for reuse as terrazzo material The By setting the temperature of the subcritical water in the range of 180 ° C. to 280 ° C., valuable materials derived from the thermosetting resin can be collected more selectively. Boehmite can be recovered. By using subcritical water, an excellent decomposition method is realized in terms of handling, recovery, cost, and the like.

According to a second aspect of the invention for adding A alkali hydrolysis reaction is promoted to improve the resin dissolution rate, it is to enable more efficient decomposition, alkali metals, alkaline earth as in the third invention as an alkali This efficiency can be further increased by using a similar metal or basic phosphate .

  The present invention has the features as described above, and an embodiment thereof will be described below.

Artificial marble used as a decomposition of the target in the present invention, the composed composition mainly inorganic filler and a thermosetting resin, as such artificial marble, aluminum hydroxide as a non-machine filler, an epoxy thermosetting resin A vinyl ester artificial marble using an acrylate resin (also called a vinyl ester resin) can be given.

  And in this invention, water, an organic solvent, etc. are added to such artificial marble (mainly waste), temperature and pressure are raised, a thermosetting resin is dissolved under a subcritical state, and valuable resources are obtained. At the same time, the valuable material derived from the inorganic filler is separated and collected as a solid residue. The ratio of the artificial marble and the solvent that becomes a subcritical state such as water or an organic solvent is not particularly limited, but is preferably set in the range of 100 to 500 parts by mass with respect to 100 parts by mass of the artificial marble.

Generally, it is considered that the thermosetting resin is decomposed by the subcritical fluid by a thermal decomposition reaction and a hydrolysis reaction. That is the same also in the artificial marble and a thermosetting resin is used et Po carboxymethyl acrylate resin (vinyl ester resin), when contacted with subcritical fluids, the ester bond portion of the hydrolysis reaction First, this triggers a thermal decomposition reaction, which becomes a monomer or a further decomposed compound, and valuable materials can be obtained by separating and recovering them. At the same time, valuable materials derived from inorganic fillers remaining as solid residues can be obtained.

  The temperature of the decomposition reaction is preferably set in the range of 180 to 370 ° C. If the temperature is lower than 180 ° C., it takes a long time for decomposition, which may increase the processing cost. Also, in the range of 180 to 280 ° C., polymer valuables that can be easily reused as a thermosetting resin production raw material are mainly recovered by suppressing excessive thermal decomposition reaction of the thermosetting resin. . In the range of 280 to 370 ° C., the thermosetting resin is easily dissolved, and the inorganic filler and the thermosetting resin can be separated, which is effective for reuse of the inorganic filler. When it exceeds 370 ° C., excessive thermal decomposition of the thermosetting resin tends to occur, and the recovery amount of valuable materials derived from the thermosetting resin decreases.

As a solvent for decomposition, water, an organic solvent such as alcohol and ether, CO ₂ , and a mixture thereof are appropriately used, but it is more preferable to use water in terms of handling, recovery, cost, and the like. .

  Furthermore, by allowing alkali to coexist in the subcritical fluid, the hydrolysis reaction is promoted and the resin dissolution rate can be improved. Here, although the addition amount of an alkali is not specifically limited, The range of 0.01-50 mass parts is preferable with respect to 100 mass parts of artificial marble. Moreover, the kind of alkali to add is considered that the 1 or more types of alkali of 1A group (alkali metal), 2A group (alkaline earth metal), and basic phosphate is suitable. Of these, KOH and NaOH are desirable.

  The time for the decomposition reaction varies depending on the reaction temperature and other conditions, but is preferably 0.1 to 10 hours. A shorter reaction time is more preferable because the processing cost is reduced. The pressure during the decomposition reaction is not particularly limited, but is preferably set in the range of about 2 to 17 MPa.

  Therefore, an example will be shown below and will be described in more detail. Of course, the invention is not limited by the following examples.

Example 1
Vinyl ester artificial marble, vinyl ester resin (manufactured by Japan Composite Co., Ltd.) as the thermosetting resin, produced by using aluminum hydroxide as an inorganic filler (manufactured by Sumitomo Chemical Co., Ltd.).

  3.8 g of vinyl ester-based artificial marble ground (3 mm mesh) and 15.2 g of pure water were weighed and sealed in a reaction tube. This was immersed in a constant temperature bath at 230 ° C., the inside of the reaction tube was placed in a subcritical state, left standing for 4 hours, and the artificial marble was decomposed for 4 hours. Thereafter, the reaction tube was taken out from the thermostatic bath, immersed in a cooling bath, rapidly cooled to room temperature.

  The content of the reaction tube after the decomposition treatment was a water-soluble component and a solid residue, and the content was filtered to separate the solid content and collect it from the reaction tube. The dissolution rate of the resin component contained in the artificial marble was calculated from the solid residue. The dissolution rate of this resin component was calculated by the following formula.

Resin component dissolution rate (%) = [Amount of resin contained before treatment (g) −Amount of resin contained in solid residue (g)] / Amount of resin contained before treatment (g) × 100
The water-soluble component was qualitatively analyzed by GC-MS. The results obtained are shown in Table 1.
( Reference Example 1 )
The acrylic artificial marble was produced using acrylic syrup (manufactured by Lucite Japan) using thermosetting acrylic resin as the thermosetting resin and fused silica as the inorganic filler.

Thereafter, a decomposition treatment was performed in the same manner as in Example 1 except that the artificial marble used was an acrylic artificial marble, a resin dissolution rate was calculated, and a qualitative analysis was performed.
(Example 2 )
A decomposition treatment was performed in the same manner as in Example 1 except that the pure water of Example 1 was changed to 1N KOH, a resin dissolution rate was calculated, and a qualitative analysis was performed.
(Example 3 )
A decomposition treatment was performed in the same manner as in Example 1 except that the pure water of Example 1 was changed to 1N NaOH, and a resin dissolution rate was calculated and a qualitative analysis was performed.
( Reference Example 2 )
The decomposition treatment was performed in the same manner as in Reference Example 1 except that the pure water of Reference Example 1 was changed to 1N KOH, and the resin dissolution rate was calculated.
( Reference Example 3 )
The decomposition treatment was performed in the same manner as in Reference Example 1 except that the pure water of Reference Example 1 was changed to 1N NaOH, and the resin dissolution rate was calculated.
(Example 4 )
Example 1 except that the amount of charged vinyl ester-based artificial marble (3 mm mesh) in Example 1 was 2.88 g, the amount of pure water was 11.6 g, the temperature was 350 ° C., and the decomposition treatment time was 2 hours. In the same manner as above, decomposition treatment was performed, and the resin dissolution rate was calculated.
( Reference Example 4 )
Reference Example 1 of the acrylic artificial marble ground product (3mm mesh) were charged amount 2.88 g, pure water was charged amount 11.5 g, 350 ° C. The temperature, except that the decomposition treatment time 2 hours Reference Example 1 Similarly, the decomposition treatment was performed and the resin dissolution rate was calculated.
(Example 5 )
The decomposition treatment was performed in the same manner as in Example 4 except that the pure water of Example 4 was changed to 1N KOH, and the resin dissolution rate was calculated.
( Reference Example 5 )
The decomposition treatment was performed in the same manner as in Reference Example 4 except that the pure water of Reference Example 4 was changed to 1N KOH, and the resin dissolution rate was calculated.
(Comparative Example 1)
In Example 1, the processing temperature was 170 ° C.
(Comparative Example 2)
In Reference Example 2 , the treatment temperature was 170 ° C.
(Comparative Example 3)
In Reference Example 4 , the treatment temperature was 380 ° C.
(Comparative Example 4)
In Example 5 , the treatment temperature was 380 ° C.
(Evaluation)
The results of Examples 1 to 5, Reference Examples 1 to 5 and Comparative Examples 1 to 4 are shown in Table 1 and Table 2, respectively.

The vinyl ester resin-derived solubilized product recovered in Examples 1, 2 , and 3 was a styrene-methacrylic acid copolymer and an epoxy skeleton. Moreover, it was confirmed from the X-ray diffraction analysis of the solid residue that the aluminum hydroxide was converted to boehmite. This is produced by dehydration of aluminum hydroxide and can be used as an inorganic flame retardant filler for thermoplastic resins.

The solubilized product derived from the acrylic resin recovered in Reference Examples 1 to 3 was methacrylic acid. Moreover, it was confirmed from the X-ray diffraction analysis of the solid residue that silica (SiO ₂ ) remained.

In each of Examples 4 to 5 , it was confirmed that ethanol, isobutyric acid, phenol, and isopropenyl phenyl were produced in the solubilizate derived from the vinyl ester resin. Moreover, it was confirmed from the X-ray diffraction analysis of the solid residue that the aluminum hydroxide was converted to boehmite.

In Reference Examples 4 to 5 , it was confirmed that methanol, ethanol, and chloroform were produced, but the amount was very small, and it was difficult to recover and reuse. Moreover, it was confirmed from the X-ray diffraction analysis of the solid residue that silica (SiO ₂ ) remained.

  From the above results, in the vinyl ester-based artificial marble according to the present invention, resin-derived styrene-methacrylic acid copolymer, epoxy skeleton, or boehmite derived from an inorganic filler can be recovered and reused. In acrylic artificial marble, methacrylic acid derived from resin or silica as an inorganic filler can be recovered and reused.

  As is clear from the comparison between the Examples and Comparative Examples 1 to 4, the recovery rate is remarkably reduced when the treatment temperature is 170 ° C. less than 180 ° C. and when the treatment temperature is 380 ° C. exceeding 370 ° C. I understand.

Claims (3)

A vinyl ester-based artificial marble mainly containing an inorganic filler and a thermosetting resin, wherein the inorganic filler is aluminum hydroxide and the thermosetting resin is a vinyl ester resin, in a temperature range of 180 ° C. to 280 ° C. A water-soluble component containing a valuable material of a polymer derived from the thermosetting resin and a boehmite derived from the inorganic filler by treating with subcritical water and solid-liquid separation of the treated subcritical water. A method for decomposing artificial marble, comprising collecting solid residue . Artificial marble decomposition method according to claim 1, characterized in Rukoto coexist alkali subcritical water. Alkali Group 1A coexist (alkali metal), Group 2A (alkaline earth metals), and degradation of the artificial marble according to claim 2, wherein at least one Der Rukoto of basic phosphate Method.