JP5519265B2 - Detergent builder - Google Patents

Description

  The present invention relates to detergent builders.

  Conventionally, most plastic wastes made from thermosetting resins have been disposed of in landfills. However, there is a problem that it is difficult to secure a land for landfill, and there is a problem that the ground becomes unstable after landfill, and it is desired to recycle plastic waste made from this thermosetting resin.

So far, decomposition methods of thermosetting resins using supercritical water or subcritical water as a reaction medium have been proposed (see, for example, Patent Documents 1 and 2), but these decomposition products are reused as they are. I couldn't. Therefore, Patent Documents 3-5 propose a method for recovering and reusing a thermosetting resin by applying the above-described decomposition method to newly modify the decomposition product so that it can be reused. Furthermore, the present applicant has proposed a modified styrene fumaric acid copolymer that can be reused as a low shrinkage material for a thermosetting resin (see, for example, Patent Document 6).
Japanese Patent Laid-Open No. 10-24274 JP 2004-155964 A JP 2005-336322 A JP 2006-36938 A International Publication WO2006 / 057250 Pamphlet JP 2008-31412 A

  However, all of the literatures reported so far have been mainly aimed at decomposing thermosetting resins, and the properties of the decomposed products have not been sufficiently studied, and the applications for reuse have been limited. It was.

  This invention is made | formed in view of the situation as mentioned above, and makes it a subject to provide the detergent builder which enabled recycling of plastic waste.

  The present invention is characterized by the following in order to solve the above problems.

  1stly, it is a detergent builder characterized by including the decomposition product aqueous solution after subcritical water decomposition | disassembly of the thermosetting resin containing a polyester part and its bridge | crosslinking part in alkali coexistence.

  Secondly, the detergent builder described above includes a polybasic alcohol and a polybasic acid or a derivative thereof whose degradation product aqueous solution is a monomer derived from a polyester of a thermosetting resin raw material, and a polybasic acid-vinyl monomer derived from a cross-linked portion Contains a copolymer salt.

  According to the first and second aspects of the present invention, a detergent builder having an excellent effect of Ca ion capturing ability and alkali buffering ability as a chelating function is provided. Since this is obtained by decomposing a thermosetting resin such as FRP (fiber reinforced plastic), it is possible to recycle plastic waste such as FRP by using plastic waste.

  The present invention is described in detail below.

  The detergent builder of the present invention is obtained by decomposing a thermosetting resin. This thermosetting resin is obtained by crosslinking polyester and includes a polyester part and a crosslinked part thereof.

  The polyester part is derived from a polyester in which a polyhydric alcohol residue and a polybasic acid residue are connected to each other through an ester bond by polycondensation of a polyhydric alcohol and a polybasic acid. The polyester part may contain a double bond derived from an unsaturated polybasic acid.

  A crosslinked part is a part which bridge | crosslinks a polyester part. Although a bridge | crosslinking part is a part originating in a crosslinking agent, for example, it is not specifically limited. The cross-linked part may be a part derived from one cross-linking agent, or may be a part derived from an oligomer or polymer obtained by polymerizing a plurality of cross-linking agents. Further, the bonding position and bonding mode between the crosslinked part and the polyester part are not particularly limited.

  Therefore, the “thermosetting resin including a polyester part and a cross-linked part thereof” means a reticulated thermosetting resin (a reticulated polyester resin) in which a polyester obtained from a polyhydric alcohol and a polybasic acid is cross-linked via a cross-linked part. It is.

  The thermosetting resin is a resin that is cured (crosslinked) mainly by heating or the like, but may be an uncured resin that is cured (crosslinked) by heating or the like, or a partially cured resin.

  Examples of the thermosetting resin to be decomposed in the present invention include a reticulated polyester resin in which an unsaturated polyester composed of a polyhydric alcohol and an unsaturated polybasic acid is crosslinked with a crosslinking agent.

  Specific examples of the polyhydric alcohol that is a raw material for the polyester portion include glycols such as ethylene glycol, propylene glycol, neopentyl glycol, diethylene glycol, and dipropylene glycol. These can be used alone or in combination of two or more.

  Specific examples of the polybasic acid that is a raw material for the polyester part include unsaturated polybasic acids such as aliphatic unsaturated dibasic acids such as maleic anhydride, maleic acid, and fumaric acid. These can be used alone or in combination of two or more. A saturated polybasic acid such as phthalic anhydride may be used in combination with the unsaturated polybasic acid.

  A cross-linking agent that cross-links a polyester that is a copolymer of a polyhydric alcohol and a polybasic acid is an unsaturated, hydrophobic vinyl monomer. Specific examples include styrene, methyl methacrylate, monochlorostyrene, diallyl phthalate, triallyl phthalate, and the like.

  The thermosetting resin to be decomposed in the present invention contains inorganic fillers such as calcium carbonate and aluminum hydroxide, inorganic substances such as glass fibers such as chopped strands obtained by cutting rovings, and other components. May be.

In the present invention, the thermosetting resin as described above is decomposed with water (hereinafter also referred to as subcritical water) in which water as a solvent is added in the presence of an alkali and the temperature and pressure are raised to a subcritical state. The The addition amount of the solvent is preferably in the range of 200 to 500 parts by mass with respect to 100 parts by mass of the thermosetting resin. The alkali is used to produce a polybasic acid-vinyl monomer copolymer such as a styrene fumaric acid copolymer obtained by decomposition as a water-soluble resin. By allowing the alkali to coexist with water, the terminal part of the carboxylic acid of the polybasic acid-vinyl monomer copolymer becomes an anionic salt (polybasic acid-vinyl monomer copolymer salt). As a result, the entire polybasic acid-vinyl monomer copolymer is water-soluble, and the salt of the polybasic acid-vinyl monomer copolymer contains a divalent or higher carboxylic acid. Also, the structure has a chelate function with the characteristic of capturing and stabilizing polyvalent cations.
Examples of the alkali include alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, ammonium salts such as ammonium carbonate and ammonium sulfate, and ammonium hydroxide, which are contained in a solvent. In view of reaction efficiency and cost, the alkali content in the solvent is generally that of acid residues contained in the polybasic acid-vinyl monomer copolymer obtained by decomposing the thermosetting resin. It is preferable to set it to 2 mol equivalent or more and 10 mol equivalent or less with respect to the theoretical mol number.

  Decomposition treatment of thermosetting resin with subcritical water is generally caused by thermal decomposition reaction and hydrolysis reaction, and it is selectively hydrolyzed by setting the temperature and pressure of subcritical water to appropriate conditions. A reaction occurs, and the polyester part of the thermosetting resin is decomposed into a polyhydric alcohol and a polybasic acid or a derivative thereof, which are monomers derived from the polyester, and the part constituting the polyester part and the cross-linked part is an organic acid. Which is a polybasic acid-vinyl monomer copolymer such as a styrene fumaric acid copolymer. Examples of the derivatives include salts of polybasic acids such as fumarate, organic acids such as acetic acid, malic acid, and salts thereof, or salts thereof.

  Moreover, the compound of the organic acid which comprises the polyester part and its bridge | crosslinking part is a compound (reaction product) of the polybasic acid of a polyester part, and a bridge | crosslinking part. For example, when the polyester part has a fumaric acid group and the crosslinked part is styrene, a styrene fumaric acid copolymer is obtained as the compound. Therefore, also in the present invention, the above thermosetting resin is decomposed into a polybasic alcohol and a polybasic acid or a derivative thereof and a polybasic acid-vinyl monomer copolymer by treating the thermosetting resin in contact with subcritical water. Can do. The polyhydric alcohol and polybasic acid obtained by decomposition can be recovered and reused as a raw material for producing a thermosetting resin.

  In the present invention, “subcritical water” means that the temperature of water is not higher than the critical point of water (critical temperature 374.4 ° C., critical pressure 22.1 MPa) and the temperature is 140 ° C. or higher (in this case, ion Since the product is about 100 times the normal temperature and the dielectric constant of water is reduced to about 50% of the normal temperature, hydrolysis can be promoted and the thermosetting resin can be monomerized). Water in a state of 36 MPa (saturated vapor pressure of 140 ° C.) or higher is referred to.

  In the present invention, the temperature of subcritical water at the time of the decomposition reaction is lower than the thermal decomposition temperature of the thermosetting resin, and is preferably in the range of 180 to 270 ° C. If the temperature during the decomposition reaction is less than 180 ° C., the decomposition process takes a lot of time, which may increase the processing cost, and the yield of the polybasic acid-vinyl monomer copolymer tends to decrease. . If the temperature during the decomposition reaction exceeds 270 ° C., the thermal decomposition of the polybasic acid-vinyl monomer copolymer becomes significant, and the polybasic acid-vinyl monomer copolymer is reduced in molecular weight, resulting in a polybasic acid derivative or vinyl. It tends to be difficult to recover to a polybasic acid-vinyl monomer copolymer by being decomposed into monomers. The treatment time with subcritical water varies depending on the reaction temperature and other conditions, but is usually 1 to 8 hours. Although the pressure at the time of a decomposition reaction changes with conditions, such as reaction temperature, Preferably it is the range of 1-15 Mpa.

  As described above, by decomposing the thermosetting resin with subcritical water in the presence of alkali, the polyhydric alcohol, polybasic acid or derivative, and polybasic acid-vinyl monomer, which are polyester-derived monomers produced by the decomposition reaction The salt of the copolymer is recovered as a water-soluble component in an aqueous solution, and the undecomposed thermosetting resin is recovered as a solid component separately from the aqueous solution. When the thermosetting resin contains an inorganic substance or the like, the inorganic substance or the like is recovered as a solid content together with the undecomposed thermosetting resin.

  The aqueous solution after recovering the solid content contains a polyhydric alcohol which is a polyester-derived monomer and a polybasic acid or a derivative thereof, and a salt of a polybasic acid-vinyl monomer copolymer derived from a cross-linked portion. In the present invention, an aqueous solution containing at least one of these is used as a detergent builder. For example, an aqueous solution containing both of these is used as a detergent builder.

  In the detergent builder of the present invention, the polyester-derived monomer or derivative thereof and the salt of the polybasic acid-vinyl monomer copolymer derived from the cross-linked portion may be a mixture or a single component aqueous solution.

  In general, the detergent builder itself is not so high in cleaning ability, but it can be said that the detergent builder exhibits the same cleaning ability as that of the surfactant when incorporated in the detergent. Specific functions include alkali buffering ability and Ca ion capturing ability. Alkali buffering ability refers to the function of making the cleaning solution alkaline to facilitate the decomposition of dirt, and the ability to maintain alkalinity and maintain cleaning power when acidic dirt enters. Moreover, Ca ion capture ability shows the capability of the effect | action which makes hard water which inhibits cleaning power soft water, and maintains cleaning power.

  The detergent builder of the present invention as described above has an alkali buffering ability superior to that of an alkali metal salt of polyacrylic acid, which is also known as a general commercial product, and also has a Ca ion capturing ability. It has good performance such as being.

  The detergent builder of the present invention may be appropriately adjusted to an aqueous solution having a desired concentration by a method such as dilution according to the necessity and application in use. For example, the water-soluble component concentration of a polybasic acid and a polybasic acid or a derivative thereof, which are polyester-derived monomers, and a salt of a polybasic acid-vinyl monomer copolymer derived from a crosslinked portion is in the range of 0.01 to 8%. However, the present invention is not limited to this.

  In addition, the ratio of the polyester-derived monomer and its derivative in the aqueous solution and the ratio of the polybasic acid-vinyl monomer copolymer salt derived from the cross-linked portion can be adjusted by the decomposition conditions in the subcritical water decomposition, etc. Is done.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

<Example 1>
Unsaturated polyester was synthesized by polycondensation of glycols composed of propylene glycol, neopentyl glycol and dipropylene glycol with maleic anhydride in equimolar amounts. This unsaturated polyester varnish (no solvent added) is blended with 100 parts by mass of a liquid resin in which an equal amount of styrene as a cross-linking agent is blended, and 165 parts by mass of calcium carbonate and 90 parts by mass of glass fiber are cured and cured to be unsaturated A polyester resin molded product (hereinafter referred to as “plastic”) was prepared and pulverized to about 2 mm to facilitate measurement.

  To 4 g of plastic, 16 ml of 0.8N NaOH is used as a solvent, charged in a reaction tube, immersed in a thermostatic bath at 230 ° C. (2.8 MPa), and the pure water in the reaction tube is placed in a subcritical state and left immersed for 4 hours. Then, the plastic was decomposed.

  Thereafter, the reaction tube was taken out of the thermostatic bath and immersed in a cooling bath, and the reaction tube was rapidly cooled to room temperature. It is confirmed that the contents of the reaction tube after the decomposition treatment are a water-soluble component including glycols, fumaric acid and derivatives thereof, and a styrene fumarate copolymer, and a solid content including calcium carbonate and glass fiber. did. By filtering the contents, the water-soluble component was separated from the solid content, and the aqueous solution was recovered from the reaction tube. Using this recovered aqueous solution, Ca ion capturing ability and alkali buffering ability were evaluated by the following methods.

In addition, when the weight average molecular weight (Mw) of the melt | dissolution component in the collect | recovered aqueous solution was analyzed by GPC, it confirmed that the weight average molecular weight was 78000. Moreover, it confirmed that it was an aqueous solution of the dissolution component 8.0%. Furthermore, it confirmed that the styrene / fumaric acid molar ratio of the styrene fumarate copolymer which is one of the dissolved components was 2.2.
<Comparative Example 1>
Using a sodium salt aqueous solution of polyacrylic acid, the Ca ion capturing ability and the alkali buffering ability were evaluated by the method described below in the same manner as in Example 1.

When the weight average molecular weight (Mw) of this sodium polyacrylate was analyzed by GPC, it was confirmed to be 22000.
<Comparative example 2>
The Ca ion capturing ability and alkali buffering ability of pure water alone were evaluated by the following methods.
<Evaluation>
(1) Ca ion capturing ability The aqueous solutions of Example 1 and Comparative Example 1 were each adjusted to 0.05%.

50 ml each of the aqueous solutions of Example 1 and Comparative Example 1 adjusted to 0.05% and the pure water of Comparative Example 2 were prepared, and 0.25 ml of 10% linear alkylbenzene sulfonic acid soda solution was added to each. The pH was adjusted to 10 by adding 1 N aqueous NaOH or 0.1 N HCl. Subsequently, 1% calcium acetate aqueous solution was dripped, stirring these prepared aqueous solutions, and Ca ion capture | acquisition ability was calculated | required by the following formula | equation from the point which became cloudy.
Ca ion capturing ability (CaCO ₃ mg / g) = (titrated amount) × 5.68 / 0.25
(2) Alkaline buffer capacity The aqueous solutions of Example 1 and Comparative Example 1 were each adjusted to 2%.

50 ml of the aqueous solution of Example 1 and Comparative Example 1 adjusted to 2% and the pure water of Comparative Example 2 were prepared, and the pH was adjusted to 10 by adding 0.1 N NaOH or 0.1 N HCl. Subsequently, 0.1N HCl was dropped while stirring these prepared aqueous solutions, and the titration amount was set to be an alkaline buffering ability with the point at which the pH reached 8 as an end point.

  The results are shown in Table 1.

In Example 1, the effect of the Ca ion capture ability which shows a favorable value compared with the comparative example 2 which does not use detergent builder has been confirmed. This is considered because the anion part of the carboxylic acid present in Example 1 captured calcium ions.
Regarding the alkaline buffering capacity, Example 1 was confirmed to be superior to Comparative Example 1 as well as Comparative Example 2 in which no detergent builder was used. In Comparative Example 1, since the structural unit is acrylic acid, there is not one carboxylic acid per unit. On the other hand, in the aqueous solution of Example 1, other than a resin having a fumaric acid part with two carboxylic acids in the structural unit. Since it also contains an organic acid salt having a carboxylic acid, the ratio of the carboxylic acid per weight of the solid content is increased, and it is considered that an excellent effect of alkaline buffering ability is exhibited.
From the above, it can be seen that the aqueous solution of the present invention exhibits the effects of Ca ion capturing ability and alkali buffering ability, and in particular, is a detergent builder having excellent alkali buffering ability.

Claims (2)

A detergent builder containing an aqueous solution of a decomposition product after subcritical water decomposition of a thermosetting resin containing a polyester part and a cross-linked part thereof in the presence of an alkali , wherein the aqueous solution of the decomposition product is derived from a polyester of a thermosetting resin raw material A detergent builder comprising a polyhydric alcohol as a monomer and a polybasic acid or a derivative thereof . The detergent builder according to claim 1 , wherein the decomposition product aqueous solution further contains a salt of a polybasic acid-vinyl monomer copolymer derived from a cross-linked part.