JP2006327940A - Method of recovering - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for recovering a raw material having an extremely high degree of transparency from a material containing a fluorine-based resin and an acrylic resin safely. <P>SOLUTION: This method for recovering a monomer originated from the acrylic resin comprises a process of dissolving the acrylic resin from a material containing the fluorine-based resin and acrylic resin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention recovers acrylic resin having a very high degree of transparency from materials containing fluorine resin and acrylic resin, especially optical materials such as plastic optical fiber, polymer waveguide waste or processing end material. On how to do.

  In recent years, there has been a strong demand for the reuse of materials from the standpoint of protecting the global environment and saving resources. In particular, plastic materials used for optical materials such as plastic optical fibers and polymer waveguides are often manufactured using materials consisting of expensive and valuable resources such as deuterium and fluorine. The cost merit is larger than the recovery.

  The material is reused by dry distillation, that is, in a state substantially free of oxygen, by thermally decomposing the plastic to reduce it to a low molecular weight monomer and reusing the recovered monomer.

  For example, an acrylic resin having an easily depolymerizable component such as methyl methacrylate can be recovered in high yield as a raw material monomer constituting the resin by dry distillation. Therefore, a method for industrially recovering monomers by the dry distillation method for defective molded products made of acrylic resin, scraps generated during molding, or waste materials collected after using the molded products as products. Have been proposed (Patent Document 1).

JP 2003-321571 A

  Optical materials such as plastic optical fibers and polymer waveguides are required to have high transparency, that is, low transmission loss values, and the types of monomers used are expensive and valuable resources such as monomers substituted with deuterium or fluorine. Therefore, the monomer is required to have a very high purity.

  However, the method described in Patent Document 1 is not fully satisfactory. This is because optical materials often contain fluororesin and acrylic resin as essential components, and if these waste materials are simply placed in a heating kettle for dry distillation, there is a risk of producing highly toxic hydrofluoric acid from the fluororesin. Due to the danger of and the concern of corrosion of the reaction kettle.

  An object of the present invention is to solve the above-mentioned problems, and a raw material (acrylic resin, fluorine resin, An object of the present invention is to provide a method for safely recovering an acrylic resin-derived monomer).

The present inventors diligently studied to solve the above-mentioned problems, and found a method for recovering a raw material having extremely high transparency by the following means, and completed the present invention.
That is, the means for solving the problems are as follows.
(1) A monomer recovery method derived from an acrylic resin, comprising a step of dissolving the acrylic resin in a material containing a fluorine resin and an acrylic resin.
(2) A method for recovering an acrylic resin-derived monomer, comprising a step of dissolving an acrylic resin in a material containing a fluorine resin and an acrylic resin, and a step of depolymerizing the dissolved acrylic resin.
(3) The recovery method according to (1) or (2), wherein in the dissolving step, the solvent is dissolved using a solvent that is insoluble in the fluororesin and soluble in the acrylic resin.
(4) The recovery method according to (3), wherein the fluororesin is also recovered.
(5) The recovery method according to any one of (1) to (4), wherein the acrylic resin includes a repeating unit represented by the following general formula (1).

（一般式（１）中、Ｌ¹およびＬ²は、それぞれ独立に、水素原子（Ｈ）または重水素原子（Ｄ）を表し、ＸはＤ、Ｆ、ＣｌまたはＣＤ₃を表し、Ｒはアルキル基またはアリール基を表す。）
（６）前記フッ素系樹脂とアクリル系樹脂を含む材料は、光学材料である、（１）〜（５）のいずれかに記載の回収方法。
（７）濾別して、フッ素系樹脂を分取する工程を含む、（４）〜（６）のいずれかに記載の回収方法。
（８）前記フッ素系樹脂とアクリル系樹脂を含む材料に含まれる樹脂が有する水素原子の少なくとも一部が重水素原子である、（１）〜（７）のいずれかに記載の回収方法。
（９）貧溶剤により不要な添加剤を除去する工程を含む、（１）〜（８）のいずれかに記載の回収方法。
（１０）前記フッ素系樹脂に不溶、かつ、前記アクリル系樹脂に可溶な溶剤は、エーテル系溶剤、ケトン系溶剤およびエステル系溶剤から選択される、（３）〜（９）のいずれかに記載の回収方法。

(In General Formula (1), L ¹ and L ² each independently represent a hydrogen atom (H) or a deuterium atom (D), X represents D, F, Cl or CD ₃ , and R represents an alkyl group. Represents a group or an aryl group.)
(6) The recovery method according to any one of (1) to (5), wherein the material including the fluorine resin and the acrylic resin is an optical material.
(7) The recovery method according to any one of (4) to (6), which includes a step of separating by filtration and fractionating the fluororesin.
(8) The recovery method according to any one of (1) to (7), wherein at least a part of the hydrogen atoms contained in the resin contained in the material containing the fluororesin and the acrylic resin is a deuterium atom.
(9) The recovery method according to any one of (1) to (8), including a step of removing unnecessary additives with a poor solvent.
(10) The solvent insoluble in the fluorine resin and soluble in the acrylic resin is selected from an ether solvent, a ketone solvent, and an ester solvent, according to any one of (3) to (9) The recovery method described.

  According to the present invention, a raw material having extremely high transparency can be safely recovered from a material, in particular, an optical material such as a plastic optical fiber, a waste material of a polymer waveguide or an end material during processing.

Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
Unless otherwise specified in the present specification, H represents a normal hydrogen atom, and D represents a deuterium atom.

  First, materials used in the present invention will be described first. As a material used for raw material recovery, any material composed of a fluororesin and an acrylic resin may be used. In particular, it can be preferably used for a material containing 0.1 to 70% by weight of a fluorine resin, 10 to 99.9% by weight of an acrylic resin, and 0 to 30% by weight of other additives. Specific optical materials include plastic optical fibers and polymer waveguides.

  In the present invention, the acrylic resin is preferably cut and used, and is preferably crushed into a size that can be accommodated in a 20 mm square or 20 mm cube from the viewpoint of handling. It may be in the form of granules, powders, or chips, and may have a single shape or a combination with different shapes. In particular, there are undrawn stretched plastic optical fiber preforms (also called preforms), defective preforms, and the like.

  Fluorine resin is polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), vinylidene fluoride / tetrofluoroethylene / hexafluoropropylene copolymer, tetrafluoroethylene / perfluoroalkyl vinyl ether. Copolymer (PFA), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride / ethylene / tetrafluoroethylene copolymer (ETFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE) ), Tetrafluoroethylene / perfluoro (2,2-dimethyl-1,3-dioxonol) copolymer (Teflon AF (Teflon: registered trademark) (DuPont)), polyperfluorobutenyl vinyl Ether (Sai top (Sai top: registered trademark) (Asahi Glass Co., Ltd.)), and the like. Among these, for the purpose of optical materials such as plastic optical fibers and polymer waveguides, polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), vinylidene fluoride / tetrofluoro Ethylene / hexafluoropropylene copolymer, polyvinylidene fluoride (PVDF), tetrafluoroethylene / perfluoro (2,2-dimethyl-1,3-dioxonol) copolymer, and polyperfluorobutenyl vinyl ether are preferred. Further, tetrafluoroethylene / perfluoro (2,2-dimethyl-1,3-dioxonol) copolymer and polyperfluorobutenyl vinyl ether are very expensive, and the present invention is extremely significant from this viewpoint.

  The acrylic resin is preferably a resin that depolymerizes and returns to the monomer in a high yield by heating, and is preferably a resin containing a repeating unit represented by the following general formula (1). Here, the acrylic resin employed in the present invention may include only one type of repeating unit represented by the general formula (1), or may include two or more types.

（一般式（１）中、Ｌ¹およびＬ²は、それぞれ独立に、水素原子（Ｈ）または重水素原子（Ｄ）を表し、ＸはＤ、Ｆ、ＣｌまたはＣＤ₃を表し、Ｒはアルキル基、アリール基を表す。）

(In General Formula (1), L ¹ and L ² each independently represent a hydrogen atom (H) or a deuterium atom (D), X represents D, F, Cl or CD ₃ , and R represents an alkyl group. Represents an aryl group.)

In general formula (1), L ¹ and L ² are each preferably D, and more preferably D. Furthermore, it is preferable that 90% or more of those corresponding to L ¹ or L ² in the acrylic resin is D.
X is preferably D, F or CD ₃ .
When R is an alkyl group, it may be linear, branched or cyclic, and preferably has 1 to 18 carbon atoms. The alkyl group may have a substituent, and the substituent is preferably a fluorine atom.
When R is an aryl group, those having a total carbon number of 6 to 10 are preferred. The aryl group may have a substituent, and the substituent is preferably a fluorine atom.
Furthermore, the hydrogen atom contained in the group represented by R may be a normal hydrogen atom (H) or a deuterium atom (D), but is preferably a deuterium atom.
Although the repeating unit represented by General formula (1) below is illustrated below, this invention is not limited to these.

  By the method of the present invention, for example, the monomer represented by the general formula (1-1) can be recovered.

一般式（１−１）中、Ｌ¹、Ｌ²、ＸおよびＲは、一般式（１）におけるこれらと同義であり、好ましい範囲も同義である。

In General Formula (1-1), L ¹ , L ² , X, and R have the same meanings as those in General Formula (1), and the preferred ranges are also the same.

Next, a process for recovering raw materials from optical materials made of these materials will be described.
For example, it can be recovered by the following steps.
(1) The acrylic resin in the optical material is dissolved with a solvent.
(2) The fluororesin (solid) and the acrylic resin (solution) are separated by filtration.
(3) Remove the solvent and, if necessary, additives from the acrylic resin solution.
(4) Acrylic resin is distilled.
(5) The distillation solution is purified by distillation under reduced pressure.
Thus, in step (2), the fluororesin is recovered as one of the raw materials, and in step (5), the monomer derived from the acrylic resin as another raw material is recovered.

The dissolution step (1) of the raw material recovery process of the present invention will be described. The first purpose of the dissolution step is to separate the fluororesin and the acrylic resin. This is because, as described above, the fluororesin has a risk of generating highly toxic hydrofluoric acid by thermal decomposition. For this purpose, a solvent that is insoluble in the fluorine-based resin and soluble in the acrylic resin is used. A solvent having a boiling point of 100 ° C. or lower is preferable. More preferably, ether type, ketone type or ester type solvents are preferred. That is, the above-mentioned fluorine-based resin is not substantially dissolved in ether, ketone and ester solvents. In fact, in the case of tetrafluoroethylene resin (PTFE), a resin weight increase of 0.8% is observed in diethyl ether. Specific solvents include n-propyl ether, n-butyl ether, isobutyl ether, sec-butyl ether, n-aluminum ether, tert-butyl methyl ether, n-butyl ethyl ether, ethylene glycol. , N-butyl ether, tetrahydrofuran, dioxane, carbitol acetate, butyl carbitol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc., ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, etc. Butyl, 2-ethoxyethyl acetate, cellosolve acetate and the like are preferable, and more preferable examples of the ether solvent include tert-butyl methyl ether, tetrahydro Emissions, dioxane, as the ketone solvent include acetone, methyl ethyl ketone, the ester-based solvent, ethyl acetate.
The melting temperature in the melting step is preferably room temperature to 100 ° C., more preferably room temperature to 80 ° C. The dissolution is preferably performed with stirring.

  As described above, since the fluororesin has a risk of generating highly toxic hydrofluoric acid by thermal decomposition, it is not thermally decomposed, only the acrylic resin is dissolved, and separated by filtration (step (2)) to remove the fluororesin. It is preferable to collect. The recovered fluororesin may swell somewhat depending on the solvent used. In that case, the solvent may be removed by drying under reduced pressure at 100 ° C. or lower. The fluororesin thus obtained can be reused after being pelletized.

  Next, in step (3), the acrylic resin solution of the filtrate may contain various unnecessary additives in addition to the acrylic resin. For example, in the case of a refractive index distribution type plastic optical fiber, a refractive index adjusting agent (also referred to as a dopant) may be added to the acrylic resin in a weight ratio of about 10% in order to impart a refractive index distribution. When the next dry distillation step is performed with the dopant mixed, the purity of the resulting acrylic monomer may be significantly impaired. As the dopant, a compound having a good compatibility with the acrylic resin is often selected, so that it is dissolved in the same solvent as the acrylic resin. Therefore, it is preferable to reprecipitate and purify the acrylic resin by introducing the acrylic resin solution into a solvent (poor solvent) that is insoluble in the acrylic resin and soluble in the additive (dopant). When the dopant is a liquid, the selection range of the poor solvent is widened. Examples of the poor solvent include methanol and hexane. In this step, the additive containing the dopant is removed to obtain high-purity acrylic resin powder or pellets. Since the acrylic resin thus obtained contains dust, it cannot be used for plastic optical fibers, polymer waveguides, etc. that require very high transparency, and is preferably in the form of a monomer.

 Next, in step (4), the dry distillation is preferably carried out by putting an acrylic resin into a heating kettle and heating in an inert gas atmosphere in a state substantially free of oxygen. In that case, the oxygen concentration is preferably 1% by volume or less. Moreover, dry distillation can also be carried out by heating in a state where oxygen is not substantially present by reducing the pressure in the heating kettle. In that case, the oxygen partial pressure is preferably 1 kPa or less.

  As a method for charging the acrylic resin into the heating kettle, the acrylic resin may be previously charged in the heating kettle, or may be continuously charged into the heating kettle. It is preferable to continuously add an acrylic resin having a weight corresponding to the weight of the dry distillation liquid. As a result, it can be recovered with a higher yield.

  In the present invention, the temperature of the heating kettle may be maintained at a temperature suitable for dry distillation, for example, a temperature of 200 to 700 ° C., but a range of 250 to 600 ° C. is preferable in order to recover a high purity monomer, A range of 500 ° C. is more preferable. By setting the temperature to 200 ° C. or higher, it is possible to more effectively suppress the slow distillation rate and the longer decomposition time, and it is economical. Furthermore, it is preferable because production of dimers, trimers and the like can be reduced. On the other hand, by setting the temperature to 700 ° C. or lower, it is possible to more effectively prevent the generated gaseous thermal decomposition product from being further decomposed due to the thermal history, and the recovery rate is further improved. The impurities can be reduced.

  Regarding the heating during dry distillation, the entire inner wall of the heating pot may be heated, but the inner wall in contact with the acrylic resin may be heated, and only the lower surface of the heating pot may be heated.

  The gaseous pyrolysis product generated by heating the acrylic resin as described above is taken out from the heating kettle, and then condensed and liquefied by a known method using a heat exchanger type cooler or the like. The liquefied product is purified by distillation or the like, and the monomer is recovered.

In particular, in the present invention, when using a deuterated acrylic resin (especially one in which 95% or more of the hydrogen atoms in the resin are deuterium atoms) as a material, the separation from the fluororesin is effective. The solvent is preferably an ether solvent, specifically tetrahydrofuran (THF), and the dissolution temperature is preferably a temperature at which THF is refluxed (for example, 80 to 90 ° C.). The temperature is once lowered from room temperature to around 40 ° C., and the fluororesin (solid) and the acrylic resin (solution) are separated by filtration. The obtained acrylic resin solution (which may contain a dopant) is added little by little to a poor solvent that dissolves a dopant such as methanol but does not dissolve the acrylic resin, thereby obtaining an acrylic resin solid. It is preferable to enter the dry distillation step after sufficiently removing the solvent by drying.
In the present invention, when a fluorine-containing acrylic resin is used as a material, it is preferable to adopt the same means as described above.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

Stretched resin pulverized body of plastic optical fiber preform In each of Examples 1 to 3 and Comparative Example 1 below, a collection of stretched residues of plastic optical fiber preform was pulverized, and fluorine resin and acrylic A pulverized body made of a resin was used.

Analysis of recovered monomer The purity of the recovered monomer obtained was measured by gas chromatography and liquid chromatography.

Example 1
Refractive index distribution type plastic optical fiber comprising clad: PVDF, core: deuterated methyl methacrylate (Exemplary Compound Example P-1), dopant: diphenyl sulfide (DPS) described in Example 1 of JP-A-2005-096142 Resin A, which is the stretch draw remaining of the preform, was employed.
20 kg of Resin A was added to 400 L of tetrahydrofuran (THF) and stirred at 70 ° C. for 5 hours to dissolve the acrylic resin (Exemplary Compound P-1). After slowly cooling to 40 ° C., PVDF, a fluororesin, was filtered off. The PVDF separated by filtration was distilled off the residual solvent at 0.4 kpa at 50 ° C. for 2 days. The amount of PVDF obtained was 0.9 kg. With respect to the obtained PVDF, it was confirmed that there was no problem in transmission loss when a pipe was molded again by melt extrusion and used again as a clad resin for a plastic optical fiber. Further, no coloring was observed during melt extrusion molding.
The THF solution of Resin A was concentrated under reduced pressure and then poured into 800 L of methanol to obtain 18.8 kg of a solid precipitate of acrylic resin. It was dried under reduced pressure (0.4 kpa) for 2 days at 50 ° C., and the residual solvent was removed to obtain 18.5 kg of a purified acrylic resin solid product.
A stainless steel cylindrical saddle-type heating kettle with a two-blade type anchor type stirring blade was prepared. The heating surface temperature of the heating kettle was 500 ° C., purge nitrogen gas was supplied into the heating kettle at 5 L / hour, and the oxygen concentration in the heating kettle was 1 vol% or less.
2 kg of acrylic resin solid purified product is charged from the raw material inlet on the upper surface of this stainless steel cylindrical vertical heating kettle, and thereafter deuterated methyl methacrylate (MMA-d8) vapor, which is a monomer generated by the decomposition of the acrylic resin. Is recovered from the monomer vapor outlet on the upper lid surface of the heating kettle, condensed and liquefied with an external cooling condenser through -5 ° C cold water, and an acrylic resin solid having a weight corresponding to the weight of the obtained dry distillation liquid. The purified product was added at a rate of 100 g / times, and the amount of stay in the heating kettle was kept almost constant. This carbonization operation was continued for 12 hours to obtain a carbonization solution. The total input amount of the acrylic resin was 18.5 kg. Moreover, the obtained dry distillation liquid was 15.9 kg.
Subsequently, the carbonized solution was charged into a glass Oldershaw type 30-stage distillation column having an inner diameter of 46 mm and distilled under a reduced pressure of 40 kPa at a reflux ratio of 3. After cutting 5% by weight of the initial fraction, the recovery of the deuterated methyl methacrylate monomer was started, and finally, distillation was terminated leaving 15% by weight of a high boiling point product. 12.9 kg of highly pure deuterated methyl methacrylate monomer having a purity of 99.6% and an impurity (methyl isobutyrate) of 0.10% was recovered.

Example 2
Clad: PVDF, Core: Refractive index distribution type consisting of 9/1 (weight ratio) copolymer of deuterated methyl methacrylate (Exemplary Compound P-1) and deuterated benzyl methacrylate (Exemplary Compound P-4) The resin B remaining after drawing of the plastic optical fiber preform was used.
20 kg of Resin B was added to 400 L of tetrahydrofuran (THF) and stirred at 70 ° C. for 5 hours to dissolve Resin B (Exemplary Compound P-1 / Exemplary Compound P-4) copolymer. After slowly cooling to 40 ° C., PVDF, a fluororesin, was filtered off. The PVDF separated by filtration was distilled off the residual solvent at 0.4 kpa at 50 ° C. for 2 days. The amount of PVDF obtained was 0.8 kg.
The THF solution of Resin B was concentrated under reduced pressure, and then poured into 800 L of methanol to obtain 18.5 kg of a solid precipitate of acrylic resin. The remaining solvent was removed by drying under reduced pressure (0.4 kpa) at 50 ° C. for 2 days to obtain 18.0 kg of a purified acrylic resin solid.
2 kg of a solid precipitate of acrylic resin is introduced from the raw material inlet on the upper surface of the stainless steel cylindrical vertical heating kettle as in Example 1, and thereafter, deuterated methyl methacrylate (MMA), which is a monomer generated by the decomposition of the acrylic resin. -D8) and deuterated benzyl methacrylate (BzMA-d12) vapors are recovered from the monomer vapor outlet at the top of the heating kettle and condensed and liquefied with an external cooling condenser through -5 ° C cold water, A solid precipitate of acrylic resin having a weight commensurate with the weight of the obtained dry distillation liquid was added at a rate of 100 g / time, and the amount of stay in the heating kettle was kept substantially constant. This carbonization operation was continued for 12 hours to obtain a carbonization solution. The total input amount of the acrylic resin was 18.0 kg. Moreover, the obtained dry distillation liquid was 15.0 kg.
Subsequently, the carbonized solution was charged into a glass Oldershaw type 30-stage distillation column having an inner diameter of 46 mm and distilled under a reduced pressure of 40 kPa at a reflux ratio of 3. After 5% by weight of the initial fraction was cut, recovery of the deuterated methyl methacrylate monomer was started, and then distilled under a reduced pressure of 5 kPa with a reflux ratio of 3. After cutting 10% by weight of the first fraction, the distillation of the deuterated benzylmethacrylate monomer was started and finally 13% by weight of a high-boiling product was left to complete the distillation. A high purity deuterated methyl methacrylate monomer (10.2 kg) having a purity of 99.6% and an impurity (methyl isobutyrate) of 0.10% and a deuterated benzyl methacrylate monomer (1.2 kg) having a purity of 99.4% were recovered.

Example 3
Clad: TFE / VDF copolymer, Core: 2/1 (mass ratio) of deuterated trifluoroethyl methacrylate (Exemplary Compound Example P-2) and deuterated pentafluoromethyl methacrylate (Exemplary Compound Example P-3) The resin C, which is the undrawn stretched plastic optical fiber preform made of a copolymer, was employed.
20 kg of Resin C was put into 400 L of tetrahydrofuran (THF) and stirred at 70 ° C. for 5 hours to dissolve Resin C (P-2 / P-3 copolymer). After slowly cooling to 40 ° C., PVDF, a fluororesin, was filtered off. The PVDF separated by filtration was distilled off the residual solvent at 0.4 kpa at 50 ° C. for 2 days. The amount of PVDF obtained was 0.8 kg.
The THF solution of Resin C was concentrated under reduced pressure and then poured into 800 L of methanol to obtain 18.6 kg of a solid precipitate of acrylic resin. The remaining solvent was removed by drying under reduced pressure (0.4 kpa) at 50 ° C. for 2 days to obtain 18.3 kg of a purified acrylic resin solid product.
Thereafter, the same process as in Example 2 was performed. As a result, 9.3 kg of a highly pure deuterated trifluoroethyl methacrylate monomer having a purity of 99.6% and a deuterated pentafluoromethyl methacrylate monomer having a purity of 99.3% were obtained. 9 kg was recovered.

Comparative Example 1
In Example 1, the resin A was directly carried out from the dry distillation step without performing the dissolution step. Since the generation of hydrofluoric acid was observed during the carbonization, the heating temperature was lowered to 350 ° C. Therefore, the time required for dry distillation was 36 hours. Corrosion due to hydrofluoric acid was observed in the heating kettle. The dry distillation liquid also had a strange odor that was thought to be derived from the dopant diphenyl sulfide. As a result of distillation purification of a part of the dry distillation liquid, only deuterated methyl methacrylate monomer having a purity of 96.6% and an impurity (methyl isobutyrate) of 0.40% could be recovered. In the distilled monomer, an unpleasant odor thought to be derived from the dopant diphenyl sulfide was also observed. From this, the dissolution process is carried out, and even if the fluororesin is removed by filtration, if the solvent is concentrated without reprecipitation purification, dopant-derived impurities are mixed when used in the dry distillation process.

Claims (10)

A method for recovering an acrylic resin-derived monomer, comprising a step of dissolving an acrylic resin in a material containing a fluorine resin and an acrylic resin. A monomer recovery method derived from an acrylic resin, comprising a step of dissolving an acrylic resin in a material containing a fluorine resin and an acrylic resin, and a step of depolymerizing the dissolved acrylic resin. The recovery method according to claim 1 or 2, wherein, in the dissolving step, the solvent is dissolved using a solvent that is insoluble in the fluororesin and soluble in the acrylic resin. The recovery method according to claim 3, wherein the fluororesin is also recovered. The recovery method according to any one of claims 1 to 4, wherein the acrylic resin contains a repeating unit represented by the following general formula (1).

(In General Formula (1), L ¹ and L ² each independently represent a hydrogen atom (H) or a deuterium atom (D), X represents D, F, Cl or CD ₃ , and R represents an alkyl group. Represents a group or an aryl group.) The recovery method according to claim 1, wherein the material containing the fluororesin and the acrylic resin is an optical material. The recovery method according to any one of claims 4 to 6, further comprising a step of separating the fluororesin by filtration. The recovery method according to any one of claims 1 to 7, wherein at least a part of the hydrogen atoms contained in the resin containing the fluororesin and the acrylic resin is a deuterium atom. The collection | recovery method of any one of Claims 1-8 including the process of removing an unnecessary additive with a poor solvent. The recovery according to any one of claims 3 to 9, wherein the solvent insoluble in the fluororesin and soluble in the acrylic resin is selected from an ether solvent, a ketone solvent, and an ester solvent. Method.