Composition for decomposing polyurethane, decomposed product of polyurethane, method for producing decomposed product of polyurethane, and method for decomposing polyurethane resin

Abstract

To provide a technique for yielding a decomposed product of polyurethane.SOLUTION: A composition for polyurethane decomposition comprises a compound A and a compound B. The compound A is at least one compound selected from the group consisting of polyethylene glycol represented by the following general formula (I), an amino alcohol lacking a primary amino group and a secondary amino group, and an alkanediol having 3 to 10 carbon atoms. The compound B is at least one compound selected from the group consisting of glycerin and polyglycerin having a hydroxyl value of 1150 mgKOH / g or more. HO(CH2CH2O)nH (I) (where n is an integer of 2 or more and 17 or less).SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a composition for decomposing polyurethane, a polyurethane decomposition product, a method for producing a polyurethane decomposition product, and a method for decomposing a polyurethane resin.

Background Art

[0002] Polyurethane foams are used in various fields. Attempts have been made to chemically decompose and reuse the edge materials of polyurethane foams, used polyurethane foams, etc.

[0003] Patent Document 1 describes a method for producing a recycled polyether polyol. The method for producing a recycled polyether polyol in Patent Document 1 includes a step of adding a rigid polyurethane foam to a mixture of a composition for decomposing a rigid polyurethane foam containing a specific polyol, a metal hydroxide, and water.

[0004] Patent Document 2 describes a method for liquefying a polyurethane molded article. The method for liquefying a polyurethane molded article in Patent Document 2 decomposes the polyurethane molded article with an isocyanate component having an NCO group of 5 times or more the equivalent amount with respect to the OH groups (excluding water) required for its production.

[0005] Patent Document 3 describes a method for treating waste containing a soft urethane resin. The method for treating waste containing a soft urethane resin in Patent Document 3 adds a decomposing agent to the waste containing a soft urethane resin to start a decomposition reaction, and stops the decomposition reaction at a stage where the concentration of diamine derived from the isocyanate of the soft urethane resin raw material is 2 wt% or less to obtain a paste-like intermediate product. Then, the intermediate product is reheated to obtain a final decomposition product. It is described that the final decomposition product is in a two-phase separated form.

[0006] Patent Document 4 describes a method for producing recycled polyether polyol. The method for producing recycled polyether polyol in Patent Document 4 involves thermally decomposing waste soft polyurethane foam in a mixture of polyol and metal hydroxide in the presence of water, then removing residual moisture in the decomposition solution, and subjecting the decomposition solution to addition polymerization of alkylene oxide to obtain a homogeneous recycled polyether polyol.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0008] Regarding the technology of Patent Document 1, there are concerns that the added water and metal hydroxide may affect the use of recycled polyether polyol. Regarding the technology of Patent Document 2, the polyurethane decomposition product is obtained as an isocyanate group-containing component, and there are concerns about the storage stability of the raw material. Regarding the technology of Patent Document 3, it is made into a paste-like one-component for volume reduction, but the final decomposition product is in a two-phase separated form. Therefore, in order to use the final decomposition product as a recycled raw material, it takes time to separate the liquid and solid. Regarding the technology of Patent Document 4, due to the addition polymerization of alkylene oxide, the process becomes complicated and special equipment is required. Furthermore, considering the ease of reuse of the polyurethane decomposition product, etc., it is also desired to reduce the viscosity of the polyurethane decomposition product.

[0009] The present disclosure has been made in view of the above circumstances, and an object thereof is to solve at least one of the above problems. The present disclosure can be realized in the following forms.

Means for Solving the Problems

[0010] [1] A polyurethane decomposition composition containing Compound A and Compound B, wherein Compound A is at least one compound selected from the group consisting of polyethylene glycol represented by the following general formula (I), amino alcohol having no primary amino group and secondary amino group, and alkanediol having 3 to 10 carbon atoms, Compound B is at least one compound selected from the group consisting of glycerin and polyglycerin having a hydroxyl value of 1150 mgKOH / g or more, a polyurethane decomposition composition. HO(CH2CH2O) n H ···(I) (However, n is an integer of 2 or more and 17 or less)

Advantages of the Invention

[0011] According to the present disclosure, at least one of the above problems is solved. For example, it is possible to provide a technique for easily obtaining a polyurethane decomposition product that is easy to use as a recycled urethane raw material.

Embodiments for Carrying Out the Invention

[0012] Here, desirable examples of the present disclosure are shown. [2] The polyurethane decomposition composition according to [1], which contains a tertiary amine compound having no hydroxyl group as a decomposition catalyst. [3] The polyurethane decomposition composition according to [1] or [2], further containing a polyol having a hydroxyl value of less than 150 mgKOH / g. [4] A polyurethane decomposition product obtained by decomposing a polyurethane resin with the polyurethane decomposition composition according to any one of [1] to [3]. [5] A method for producing a polyurethane decomposition product, which decomposes a polyurethane resin with the polyurethane decomposition composition according to any one of [1] to [3]. [6] A method for decomposing a polyurethane resin, which decomposes a polyurethane resin with the polyurethane decomposition composition according to any one of [1] to [3].

[0013] Hereinafter, the present disclosure will be described in detail. In this specification, for a description using "-" for a numerical range, unless otherwise specified, it includes the lower limit value and the upper limit value. For example, in the description of "10 - 20", both the lower limit value "10" and the upper limit value "20" are included. That is, "10 - 20" has the same meaning as "10 or more and 20 or less". Also, in this specification, the upper limit value and the lower limit value of each numerical range can be arbitrarily combined.

[0014] 1. Polyurethane decomposition composition The polyurethane decomposition composition is a polyurethane decomposition composition containing Compound A and Compound B. Compound A is at least one compound selected from the group consisting of polyethylene glycol represented by the following general formula (I), amino alcohol having no primary amino group and secondary amino group, and alkanediol having 3 to 10 carbon atoms. Compound B is at least one compound selected from the group consisting of glycerin and polyglycerin having a hydroxyl value of 1150 mgKOH / g or more. HO(CH2CH2O) n H ···(I) (However, n is an integer of 2 or more and 17 or less)

[0015] (1) Polyurethane resin The composition for polyurethane decomposition is used for the decomposition of polyurethane resin. The polyurethane resin is not particularly limited. The polyurethane resin is, for example, a polyurethane foam. The polyurethane foam may be any of a flexible polyurethane foam, a semi-rigid polyurethane foam, and a rigid polyurethane foam. The polyurethane foam may be a polyurethane foam having an open-cell structure or a closed-cell structure. The polyurethane foam may be a pulverized product pulverized to a predetermined size. Further, the polyurethane foam may be a cut product cut to a predetermined size. The polyurethane foam may be, for example, a scrap discharged during the production process of the polyurethane foam or a used polyurethane foam scheduled to be discarded.

[0016] (2) Compound A Compound A is at least one compound selected from the group consisting of polyethylene glycol represented by the following general formula (I), amino alcohol having no primary amino group and secondary amino group, and alkanediol having 3 to 10 carbon atoms. Only one kind of Compound A may be used, or two or more kinds may be used in combination.

[0017] HO(CH2CH2O) n H ···(I) In the general formula (I), n is an integer of 2 or more, and from the viewpoint of the compatibility of the polyurethane decomposition product, it is preferably an integer of 3 or more, more preferably an integer of 4 or more. In the general formula (I), n is an integer of 17 or less, and from the viewpoint of reducing the viscosity of the polyurethane decomposition product, it is preferably an integer of 16 or less, and may be any integer from 3 to 15. According to the polyethylene glycol of the present disclosure, it is possible to ensure suitable fluidity of the polyurethane decomposition product while suppressing phase separation of the polyurethane decomposition product.

[0018] The polyethylene glycol represented by the general formula (I) is, for example, a polyethylene glycol having a weight average molecular weight of 100 or more and less than 1000. More specifically, diethylene glycol, polyethylene glycol 100 (PEG100), polyethylene glycol 300 (PEG300), polyethylene glycol 600 (PEG600), polyethylene glycol 800 (PEG800), polyethylene glycol 1000 (PEG1000), etc. may be mentioned. Among these, one or more selected from diethylene glycol, PEG300, and PEG600 are preferable. The number after polyethylene glycol (PEG) indicates the weight average molecular weight of the polyethylene glycol. For example, polyethylene glycol 100 (PEG100) indicates a polyethylene glycol (PEG) having a weight average molecular weight of 100, and polyethylene glycol 300 (PEG300) indicates a polyethylene glycol (PEG) having a weight average molecular weight of 300. Only one kind of the compound represented by the general formula (I) may be used, or two or more kinds may be used in combination. The weight average molecular weight of the polyethylene glycol can be measured, for example, by the gel permeation column chromatography (GPC) method.

[0019] The amino alcohol as compound A is an amino alcohol having no primary amino group and no secondary amino group. According to the amino alcohol of the present disclosure, phase separation of the polyurethane decomposition product can be preferably suppressed. The reason is not clear, but it is presumed that the amino alcohol having no primary amino group and no secondary amino group contributes to the suppression of phase separation because it is less likely to react with the decomposition product compared to the amino alcohol having a primary amino group or a secondary amino group. In addition, the above amino alcohol is considered to have an effect of making the polyol and the amine component contained in the polyurethane decomposition product of the polyurethane resin compatible. The present disclosure is not limited to this reason for speculation.

[0020] The amino alcohol as Compound A has, within the molecule, at least one tertiary amino group and at least one hydroxyl group as functional groups other than hydrocarbon groups. It is preferable that the amino alcohol has a hydrocarbon group having 2 to 10 carbon atoms in total and having a hydroxyl group bonded to the nitrogen atom, and the hydrocarbon group may be interrupted by an ether group. The number of tertiary amino groups possessed by the amino alcohol is not particularly limited. The number of the above tertiary amino groups is preferably 1 or more and 4 or less, and more preferably 1 or more and 3 or less. The number of hydroxyl groups possessed by the amino alcohol is not particularly limited. The number of the above hydroxyl groups is preferably 1 or more and 4 or less, and more preferably 1 or more and 3 or less. The molecular weight of the amino alcohol is not particularly limited. The molecular weight of the amino alcohol is preferably 800 or less, more preferably 600 or less, and still more preferably 450 or less. The lower limit is not particularly limited, but is, for example, 80 or more.

[0021] The amino alcohol is preferably at least one selected from the group consisting of, for example, N,N,N’,N’-tetrakis(2-hydroxypropyl)ethylenediamine, triethanolamine, N-phenyldiethanolamine, N,N-dimethylaminohexanol, N-methyldiethanolamine, 2-dimethylaminoethanol, 1,1’,1’’-nitrilotri-2-propanol, N-n-butyl-2,2’-iminodiethanol, 2-[2-(dimethylamino)ethoxy]ethanol, 2-[[2-(dimethylamino)ethyl]methylamino]ethanol, 2-morpholinoethanol, 2-hydroxymethyl-4-benzylmorpholine, N-(2-hydroxypropyl)morpholine, 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, 2-(4-methyl-2-phenyl-1-piperazinyl)-3-pyridinemethanol, and 1-piperidineethanol. Among these, at least one selected from the group consisting of triethanolamine, N-phenyldiethanolamine, N,N,N’,N’-tetrakis(2-hydroxypropyl)ethylenediamine, and N,N-dimethylaminohexanol is more preferable. The amino alcohol may be used alone or in combination of two or more.

[0022] The alkanediol as Compound A is an alkanediol having 3 to 10 carbon atoms. The alkanediol as Compound A may be linear or branched. The position of the hydroxyl group of the alkanediol as Compound A is not particularly limited. According to the alkanediol of the present disclosure, phase separation of the polyurethane decomposition product can be preferably suppressed. From the viewpoint of reducing the viscosity of the obtained polyurethane decomposition product, the number of carbon atoms of the alkanediol is preferably 9 or less, more preferably 8 or less, and may be 7 or less, 6 or less, 5 or less, or 4 or less. The hydroxyl value of the alkanediol having 3 to 10 carbon atoms is greater than 150 mgKOH / g.

[0023] The alkane diol as compound A is preferably bonded to primary carbon atoms where two hydroxyl groups are not adjacent to each other, and more preferably an α,ω-alkane diol. In the present disclosure, "α,ω-alkane diol" has the general formula C n H 2n+2 (n is an integer from 3 to 10), among the diols obtained by substituting one hydrogen atom bonded to each of two carbon atoms of a saturated hydrocarbon (alkane) having an unbranched or branched structure with one hydroxyl group, it means a diol obtained by substituting one hydrogen atom bonded to each of two primary carbon atoms at the ends of the saturated hydrocarbon with one hydroxyl group.

[0024] Preferably, the alkane diol is at least one selected from the group consisting of 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, and 2-butyl-2-ethyl-1,3-propanediol. Among these, more preferably, it is at least one selected from the group consisting of 1,3-propanediol, 1,4-butanediol, 2-butyl-2-ethyl 1,3-propanediol, and 1,10-decanediol, and even more preferably, it is at least one selected from the group consisting of 1,3-propanediol, 1,4-butanediol, and 2-butyl-2-ethyl 1,3-propanediol. Only one kind of alkane diol may be used, or two or more kinds may be used in combination.

[0025] The addition amount of Compound A is not particularly limited. From the perspective of sufficiently decomposing the polyurethane resin, the addition amount of Compound A is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and still more preferably 2 parts by mass or more with respect to 100 parts by mass of the polyurethane resin. Considering the influence on the reactivity and physical properties when the polyurethane decomposition product is reused as a polyurethane resin raw material or the like, the addition amount of the above Compound A is preferably 50 parts by mass or less, more preferably 25 parts by mass or less, and still more preferably 15 parts by mass or less. From these perspectives, the addition amount of the above Compound A is preferably 0.5 parts by mass or more and 50 parts by mass or less, more preferably 1 part by mass or more and 25 parts by mass or less, and still more preferably 2 parts by mass or more and 15 parts by mass or less.

[0026] When the above Compound A contains an amino alcohol, the addition amount of the amino alcohol may be more than 0 parts by mass and 12 parts by mass or less, and may also be 9 parts by mass or less, 6 parts by mass or less, or 4 parts by mass or less.

[0027] When the above Compound A contains an alkanediol, the addition amount of the alkanediol may be more than 0 parts by mass and 12 parts by mass or less, and may also be 9 parts by mass or less or 6 parts by mass or less.

[0028] (3) Compound B Compound B is one or more compounds selected from the group consisting of glycerin and polyglycerin having a hydroxyl value of 1150 mgKOH / g or more. Only one type of Compound B may be used, or two or more types may be used in combination.

[0029] The hydroxyl value of the polyglycerin is 1150 mgKOH / g or more. When two or more types of polyglycerin are used, it is preferable that the hydroxyl value obtained by weighted averaging is within the above range, and it is more preferable that the hydroxyl value of each polyglycerin is within the above range. The hydroxyl value of the polyglycerin is 1150 mgKOH / g or more, and from the viewpoint of reducing the viscosity of the polyurethane decomposition product, it is preferably 1352 mgKOH / g or more. In this specification, the "hydroxyl value" means a value measured by the standard oil and fat test analysis method (pyridine acetic anhydride method, 2.3.6.2 - 1996). The method for adjusting the hydroxyl value of the polyglycerin is not particularly limited. For example, when preparing polyglycerin according to the glycerin polymerization method, glycidol polymerization method, etc., since the hydroxyl value decreases with the progress of the polymerization reaction time, the hydroxyl value can be adjusted by confirming the process of decreasing the hydroxyl value of the polyglycerin during the reaction.

[0030] Compound B is, for example, one or more selected from glycerin, diglycerin, and triglycerin. Among these, from the viewpoint of reducing the viscosity of the polyurethane decomposition product, it is preferable to contain glycerin or diglycerin, and it is more preferable to contain glycerin.

[0031] When an amino alcohol is used as the above Compound A, the hydroxyl value of the amino alcohol is preferably smaller than the hydroxyl value of Compound B. The hydroxyl value of N,N,N’,N’-tetrakis(2-hydroxypropyl)ethylenediamine, which is an example of an amino alcohol, is 769 mgKOH / g. The hydroxyl value of triethanolamine is 1130 mgKOH / g. Thus, by appropriately selecting the type of amino alcohol, the hydroxyl value of the amino alcohol can be made smaller than the hydroxyl value of Compound B.

[0032] When using an alkanediol as the above-mentioned compound A, it is preferable that the hydroxyl value of the alkanediol is smaller than the hydroxyl value of compound B. The hydroxyl value of 1,3-propanediol, which is an example of an alkanediol, is 1477 mgKOH / g. The hydroxyl value of 1,10-decanediol is 645 mgKOH / g. Thus, by appropriately selecting the type of alkanediol, the hydroxyl value of the alkanediol can be made smaller than the hydroxyl value of compound B.

[0033] The addition amount of compound B is not particularly limited. From the viewpoint of sufficiently decomposing the polyurethane resin, the addition amount of compound B is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and still more preferably 6 parts by mass or more with respect to 100 parts by mass of the polyurethane resin. The above addition amount of compound B is preferably 60 parts by mass or less, more preferably 40 parts by mass or less, and still more preferably 20 parts by mass or less in consideration of the influence on the reactivity and physical properties when the polyurethane decomposition product is reused as a polyurethane resin raw material or the like. From these viewpoints, the addition amount of the above-mentioned compound B is preferably 1 part by mass or more and 60 parts by mass or less, more preferably 5 parts by mass or more and 40 parts by mass or less, and still more preferably 6 parts by mass or more and 20 parts by mass or less.

[0034] (4) Catalyst The catalyst is a tertiary amine compound having no hydroxyl group. According to the tertiary amine compound of the present disclosure, phase separation of the polyurethane decomposition product can be preferably suppressed. The reason is not clear, but it is presumed that the tertiary amine compound contributes to the suppression of phase separation because it is less likely to react with the decomposition products compared to amine compounds having a primary amino group or a secondary amino group. It should be noted that the present disclosure is not limited to this reason for speculation.

[0035] The tertiary amine compound of the present disclosure has at least one tertiary amino group as a functional group other than a hydrocarbon group in the molecule. The number of tertiary amino groups in the tertiary amine compound is not particularly limited. The number of the above-mentioned tertiary amino groups is preferably 1 or more and 4 or less, and more preferably 1 or more and 3 or less. The molecular weight of the tertiary amine compound is not particularly limited. The molecular weight of the tertiary amine compound is preferably 600 or less, more preferably 400 or less, and still more preferably 200 or less. The lower limit is not particularly limited, but is, for example, 60 or more.

[0036] The tertiary amine compound is preferably at least one selected from the group consisting of diazabicycloundecene, triethylamine, tripropylamine, tributylamine, hexadecyldimethylamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, N,N,N',N'-tetramethylhexanediamine, N,N,N',N'-tetramethylpropanediamine, N,N,N',N'',N''-pentamethyldiethylenetriamine, N,N',N'-trimethylaminoethylpiperazine, N,N-dimethylcyclohexylamine, N,N,N',N'-tetramethylethylenediamine, and 1,4-diazabicyclo[2.2.2]octane. Only one kind of the tertiary amine compound may be used, or two or more kinds may be used in combination.

[0037] The addition amount of the tertiary amine compound is not particularly limited. From the viewpoint of sufficiently decomposing the polyurethane resin, the addition amount of the tertiary amine compound is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and still more preferably 0.3 parts by mass or more with respect to 100 parts by mass of the polyurethane resin. Considering the influence on the reactivity and physical properties when the polyurethane decomposition product is reused as a polyurethane resin raw material or the like, the addition amount of the above tertiary amine compound is preferably 8 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 3 parts by mass or less. From these viewpoints, the addition amount of the above tertiary amine compound is preferably 0.05 parts by mass or more and 8 parts by mass or less, more preferably 0.1 parts by mass or more and 5 parts by mass or less, and still more preferably 0.3 parts by mass or more and 3 parts by mass or less.

[0038] The catalyst may be used in combination with the above tertiary amine compound and other catalysts. The other catalysts are preferably one or more selected from the group consisting of stannous octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin mercaptide, dioctyltin thiocarboxylate, lead octoate, potassium acetate, and potassium octoate.

[0039] (5) Other components The polyurethane decomposition composition may further contain components other than Compound A, Compound B, and the catalyst (also referred to as other components). For example, from the viewpoint of obtaining a single-phase polyurethane decomposition product, the polyurethane decomposition composition preferably further contains a polyol having a hydroxyl value of less than 150 mg KOH / g. This polyol is, for example, a polyol excluding the polyethylene glycol represented by the above general formula (I). This polyol is, for example, a polyol excluding amino alcohols. This polyol is, for example, a polyol excluding alkanediols having 3 to 10 carbon atoms.

[0040] The type of polyol having a hydroxyl value of less than 150 mg KOH / g can be appropriately selected. The polyol having a hydroxyl value of less than 150 mg KOH / g is preferably one or more selected from, for example, polyether polyols, polyester polyols, polyether ester polyols, polycarbonate diols, and polyols having a carbon-carbon bond-based main chain. The polyol having a hydroxyl value of less than 150 mg KOH / g may be a raw material polyol for a recycled polyurethane resin using the polyurethane decomposition product described below. By using the raw material polyol for the recycled polyurethane resin, the influence of the components in the polyurethane decomposition composition on obtaining the recycled polyurethane resin can be reduced.

[0041] The addition amount of the polyol with a hydroxyl value of less than 150 mg KOH / g is not particularly limited. From the perspective of obtaining a single-phase polyurethane decomposition product, the addition amount of the above polyol is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and still more preferably 8 parts by mass or more with respect to 100 parts by mass of the polyurethane resin. When using the raw material polyol of the recycled polyurethane resin, the addition amount of the above polyol may be 10 parts by mass or more, 25 parts by mass or more, or 30 parts by mass or more. The addition amount of the above polyol is usually 200 parts by mass or less, and may be 100 parts by mass or less, 50 parts by mass or less, 30 parts by mass or less, or 20 parts by mass or less. The addition amount of the above polyol is preferably 1 part by mass or more and 200 parts by mass or less, and can be in the range of appropriately combining the above upper and lower limit values.

[0042] 2. Polyurethane decomposition product The polyurethane decomposition product is obtained by decomposing a polyurethane resin with the above-described composition for decomposing polyurethane.

[0043] The polyurethane decomposition product contains, for example, a polyol derived from the raw material polyol of the polyurethane resin and an amine component derived from the raw material isocyanate. In addition, the polyurethane decomposition product may contain a flame retardant, a catalyst, and other additives contained in the polyurethane resin.

[0044] The state of the polyurethane decomposition product is not particularly limited. The polyurethane decomposition product is preferably obtained as a single-phase liquid. In the present disclosure, the "single-phase liquid" means a liquid in which the evaluation of "phase separation" in the following examples is not "C: Clearly phase-separated." The single-phase liquid contains, for example, a polyol derived from the raw material polyol and an amine component derived from the raw material isocyanate in a solubilized state. The single-phase liquid may contain a solid content. The solid content is, for example, a component derived from a polymer polyol containing a polymer such as styrene or acrylonitrile, a flame retardant such as a phosphorus-based flame retardant or a halogen-based flame retardant.

[0045] Originally, polyurethane degradation products have poor compatibility between the phase containing polyol and the phase containing an amine component, and are prone to phase separation. For example, when ethylene glycol or diethanolamine is used as a degrading agent for polyurethane resin, the obtained polyurethane degradation product is obtained in a phase-separated state with an upper phase containing polyol and a lower phase containing an amine component. When the polyurethane degradation product is in a phase-separated state, currently, effective utilization of the lower phase has become an issue. For example, the lower phase contains many amine components other than the amine component derived from the raw material isocyanate of the polyurethane resin. Therefore, it is difficult to isolate the amine component derived from the raw material isocyanate of the polyurethane resin from the lower phase. Further, in the state where the polyurethane degradation product is phase-separated, the lower phase occupies about 30% to 40% by mass of the whole polyurethane degradation product. Thus, discarding the lower phase leads to a decrease in the recycling rate of the polyurethane resin. On the other hand, if the polyurethane degradation product can be obtained as a single-phase liquid substance, the polyurethane degradation product can be directly used for producing recycled polyurethane resin. Therefore, the separation process of polyol and amine components can be omitted, and it can contribute to reducing the amount of waste compared to the case of discarding the lower phase.

[0046] Furthermore, if the polyurethane degradation product can be obtained as a single-phase liquid substance, the generation of solid content itself becomes difficult. The reason is not clear, but it is considered as follows. That is, when the polyurethane degradation product is in a phase-separated state, it is considered that due to the localization of the polymer component derived from polymer polyol, flame retardant, etc. in either phase, the concentration becomes locally high and the solid content is likely to be generated. On the other hand, if the polyurethane degradation product can be obtained as a single-phase liquid substance, the polymer component derived from polymer polyol, flame retardant, etc. can be dispersed throughout the system, and it is considered that the generation of solid content becomes difficult. It should be noted that the present disclosure is not limitedly interpreted by this speculative reason.

[0047] The uses of the polyurethane decomposition product are not particularly limited. The polyurethane decomposition product is suitable as a raw material for recycled polyurethane resin. For example, when the polyurethane decomposition product is a one-phase liquid substance, it is easy to mix with the composition for recycled polyurethane resin as it is, and easy to reuse.

[0048] 3. Method for producing polyurethane decomposition product The method for producing the polyurethane decomposition product decomposes the polyurethane resin with the above-described composition for decomposing polyurethane.

[0049] The decomposition conditions of the polyurethane resin are not particularly limited. From the viewpoint of improving the decomposition rate, the decomposition treatment method of the polyurethane resin may be to heat the polyurethane resin together with the composition for decomposing polyurethane. When heating the polyurethane resin together with the composition for decomposing polyurethane, it is preferable to stir the mixture of the polyurethane resin and the composition for decomposing polyurethane.

[0050] The heating temperature is preferably 80°C or higher and 300°C or lower, more preferably 100°C or higher and 270°C or lower, and still more preferably 150°C or higher and 250°C or lower, from the viewpoint of suppressing the decomposition of the polyol as the polyurethane decomposition product, that is, the polyol derived from the raw material polyol while improving the decomposition rate. The decomposition treatment time is, for example, 10 minutes or more and 24 hours or less, and may be 30 minutes or more and 10 hours or less. The end point of the decomposition treatment time may be appropriately set while confirming the progress of the decomposition of the polyurethane resin according to the size of the polyurethane resin, the presence or absence of stirring, etc. Also, for example, when decomposing the polyurethane resin at a temperature of room temperature (for example, 25°C) or higher and lower than 80°C, the decomposition treatment time may be set longer than 24 hours.

[0051] 4. Method for decomposing polyurethane resin The method for decomposing the polyurethane resin decomposes the polyurethane resin with the above-described composition for decomposing polyurethane. The method for decomposing the polyurethane resin can be carried out under the same conditions as the above-described "3. Method for producing a polyurethane decomposition product". For the conditions of the method for decomposing the polyurethane resin, refer to the description of the above "3. Method for producing a polyurethane decomposition product", and detailed description is omitted.

[0052] 5. Method for producing a recycled polyurethane resin The method for producing a recycled polyurethane resin produces a recycled polyurethane resin using a polyurethane decomposition product. In the method for producing a recycled polyurethane resin, for the "polyurethane decomposition product", the description in the column of "2. Polyurethane decomposition product" is applied as it is, and the description thereof is omitted.

[0053] The recycled polyurethane resin is obtained, for example, from a composition for recycled polyurethane resin containing a polyol, an isocyanate, and a polyurethane decomposition product. The recycled polyurethane resin can be produced by a known method. In the foaming method for obtaining a polyurethane foam, there are slab foaming and mold foaming, and any of the molding methods may be used. Slab foaming is a method in which the mixed composition for recycled polyurethane resin is discharged onto a belt conveyor and foamed at normal temperature under atmospheric pressure. On the other hand, mold foaming is a method in which the mixed composition for recycled polyurethane resin is filled into a mold (molding die) and foamed in the mold.

Example

[0054] 1. Production of polyurethane resin A polyurethane foam composition (liquid A and liquid B) blended at the ratios shown in Table 1 was prepared, and a polyurethane foam was produced by slab foaming. The density of the obtained polyurethane foam was measured in accordance with JIS K7222:2005. The measured density is also shown in Table 1.

[0055] Details of each raw material are as follows. · Polyol: Polyether polyol, number average molecular weight 3000, functionality 3, hydroxyl value 56.1 mg KOH / g, product name: Sannix GP-3050NS, manufactured by Sanyo Chemical Industries, Ltd. · Amine catalyst: Product name: DABCO 33LSI, manufactured by Evonik · Foam stabilizer: Silicone foam stabilizer, product name: L-595, manufactured by Momentive · Tin catalyst: Stannous octylate, product name: MRH-110, manufactured by Johoku Chemical Co., Ltd. · Blowing agent: Water · Flame retardant: Chlorinated phosphate ester, product name: CR-504L, manufactured by Daihachi Chemical Industry Co., Ltd. · Isocyanate: Toluene diisocyanate, product name Coronate T-80, manufactured by Tosoh Corporation, NCO%: 48.2%

[0056]

Table 1

[0057] 2. Decomposition treatment of polyurethane resin (Part 1) Polyurethane decomposition compositions of Examples and Comparative Examples containing the components described in Tables 2 and 3 were prepared. The above polyurethane foam (polyurethane resin) was decomposed using the polyurethane decomposition compositions of Examples and Comparative Examples.

[0058] Details of each component are as follows. · Diethylene glycol (Compound A1): functionality 2, molecular weight 62, hydroxyl value 1810 mg KOH / g · PEG600 (Compound A2): Polyethylene glycol, functionality 2, number average molecular weight 600, hydroxyl value 187 mg KOH / g · PEG1000: Polyethylene glycol, functionality 2, number average molecular weight 1000, hydroxyl value 112 mg KOH / g · N,N,N’,N’-tetrakis(2-hydroxypropyl)ethylenediamine (Compound A3): functionality 4, molecular weight 292, hydroxyl value 769 mg KOH / g · Triethanolamine (Compound A4): Number of functional groups 3, molecular weight 149, hydroxyl value 1130 mg KOH / g · Glycerin (Compound B1): Number of functional groups 3, molecular weight 92, hydroxyl value 1830 mg KOH / g · Diglycerin (Compound B2): Number of functional groups 4, molecular weight 166, hydroxyl value 1352 mg KOH / g · Polyglycerin: Number of functional groups 8.5, molecular weight 500, hydroxyl value 954 mg KOH / g · Trimethylolpropane: Number of functional groups 3, molecular weight 134, hydroxyl value 1256 mg KOH / g · Polyol: Polyether polyol, number of functional groups 3, number average molecular weight 3000, hydroxyl value 56.1 mg KOH / g, product name: Sunnex GP-3050NS, manufactured by Sanyo Chemical Industries, Ltd. · Catalyst: Diazabicycloundecene

[0059] Examples 1 - 10 contain Compound A and Compound B. In the decomposer, Compound A1, Compound A2, Compound A3, and Compound A4 correspond to Compound A. Compound A1 and Compound A2 are polyethylene glycols represented by the above general formula (I). Compound A3 and Compound A4 are amino alcohols having no primary amino group and secondary amino group. Also, in the decomposer, Compound B1 and Compound B2 correspond to Compound B. Compound B1 is glycerin. Compound B2 is polyglycerin having a hydroxyl value of 1150 mg KOH / g or more.

[0060] In a 1 L separable flask, a polyurethane decomposition composition of Examples and Comparative Examples was added to 100 g of polyurethane resin. The addition amounts of each component of the polyurethane decomposition composition are as shown in Tables 2 and 3. After adding the polyurethane decomposition composition, it was heated with stirring at 200 °C for 6 hours to obtain a polyurethane decomposition product.

[0061]

Table 2

[0062]

Table 3

[0063] 3. Decomposition Treatment of Polyurethane Resin (Part 2) Polyurethane decomposition compositions of Examples and Comparative Examples containing the components described in Table 4 were prepared. The above polyurethane foam (polyurethane resin) was decomposed using the polyurethane decomposition compositions of Examples and Comparative Examples.

[0064] Details of each component are as follows. · 1,3 - Propanediol (Compound A5): Number of functional groups 2, molecular weight 76, hydroxyl value 1477 mgKOH / g · 1,4 - Butanediol (Compound A6): Number of functional groups 2, molecular weight 90, hydroxyl value 1247 mgKOH / g · 2 - Butyl - 2 - ethyl - 1,3 - propanediol (Compound A7): Number of functional groups 2, molecular weight 160, hydroxyl value 701 mgKOH / g · 1,10 - Decanediol (Compound A8): Number of functional groups 2, molecular weight 174, hydroxyl value 645 mgKOH / g · 1,12 - Dodecanediol: Number of functional groups 2, molecular weight 202, hydroxyl value 556 mgKOH / g · Glycerin (Compound B1): Number of functional groups 3, molecular weight 92, hydroxyl value 1830 mgKOH / g · Polyol: Polyether polyol, number of functional groups 3, number - average molecular weight 3000, hydroxyl value 56.1 mgKOH / g, product name: Sun Nix GP - 3050NS, manufactured by Sanyo Chemical Industries, Ltd. · Catalyst: Diazabicycloundecene

[0065] Examples 11 - 16 contain Compound A and Compound B. In the decomposing agent, Compounds A5, A6, A7, and A8 correspond to Compound A. Compounds A5, A6, A7, and A8 are alkanediols having 3 to 10 carbon atoms. Also, in the decomposing agent, Compound B1 corresponds to Compound B. Compound B1 is glycerin. Compound B1 is a polyglycerin having a hydroxyl value of 1150 mgKOH / g or more.

[0066] In a 1 L separable flask, the polyurethane decomposition composition of the examples and comparative examples was added to 100 g of the polyurethane resin. The addition amounts of the respective components of the polyurethane decomposition composition are as shown in Table 4. After adding the polyurethane decomposition composition, it was heated with stirring at 200 °C for 6 hours to obtain a polyurethane decomposition product.

[0067]

Table 4

[0068] 4. Evaluation method The "phase separation" of the obtained polyurethane decomposition product was evaluated by the following evaluation method. When the evaluation of phase separation is "C", the evaluation of fluidity and viscosity described later is not performed. <Phase separation> The presence or absence of phase separation was visually confirmed. The criteria for determination are as follows. A: Not phase-separated. B: Slightly non-uniform. C: Clearly phase-separated.

[0069] The "fluidity" of the obtained polyurethane decomposition product was evaluated by the following evaluation method. <Fluidity> To 100 parts by mass of the polyurethane decomposition product, 50 parts by mass of a polyether polyol (Sannix GP-3050NS) was added and diluted. 30 mL of the obtained diluted solution sample was put into a plastic cylindrical container with a capacity of 100 mL, and the container was tilted from a vertical position with the cylinder axis to a horizontal position and left standing at 25 °C for 15 minutes. The subsequent state was visually confirmed. The judgment criteria are as follows. A: The liquid level is horizontal. B: It reaches the opposite end of the container, but the liquid level does not become horizontal. C: The diluted solution does not reach the opposite end of the container.

[0070] The "viscosity" of the obtained polyurethane decomposition product was evaluated by the following evaluation method. <Viscosity> A sample of the diluted solution was obtained in the same manner as the evaluation of the above "fluidity". The E-type viscosity of the sample was measured at a measurement temperature of 25 °C using a TV25 type viscometer Type H (manufactured by Toki Sangyo Co., Ltd., measurement upper limit: 500,000 mPas·s) in accordance with JIS K 1557-5. The judgment criteria are as follows. A: Less than 50,000 mPas·s B: 50,000 mPas·s or more and less than 250,000 mPas·s C: 250,000 mPas·s or more

[0071] The obtained polyurethane decomposition product was comprehensively judged according to the following criteria. A: The evaluations of "phase separation", "fluidity", and "viscosity" are all "A". B: There is no "C" in any of the evaluations of "phase separation", "fluidity", and "viscosity". C: There is a "C" in any of the evaluations of "phase separation", "fluidity", and "viscosity".

[0072] 5. Results The evaluation results are shown together in Tables 2, 3, and 4. When the measured value of the viscosity exceeded the measurement upper limit, it was described as "exceeded the upper limit". Items that were not evaluated were set as "-".

[0073] Examples 1 - 16 satisfy the following requirements (a) and (b). Comparative Examples 1, 2, 4, 5, 8, and 9 do not satisfy the following requirement (b). Comparative Examples 3, 6, 7, and 10 do not satisfy the following requirement (a). · Requirement (a): A composition for decomposing polyurethane containing Compound A, where Compound A is at least one compound selected from the group consisting of polyethylene glycol represented by the following general formula (I), amino alcohol having no primary amino group and no secondary amino group, and alkanediol having 3 to 10 carbon atoms. HO(CH2CH2O) n H ···(I) (However, n is an integer of 2 or more and 17 or less) · Requirement (b): A composition for decomposing polyurethane containing Compound B, where Compound B is at least one compound selected from the group consisting of glycerin and polyglycerin having a hydroxyl value of 1150 mgKOH / g or more.

[0074] <Examples 1 - 10, Comparative Examples 1 - 9> For Examples 1 - 10, the comprehensive judgment was "A" or "B". On the other hand, for Comparative Examples 1 - 9, the comprehensive judgment was "C". By using Compound A and Compound B in combination, it is considered that a polyurethane decomposition product that is easier to use as a recycled urethane raw material could be obtained compared to Comparative Examples 1 - 9.

[0075] Among Comparative Examples 1 - 9, Comparative Examples 6 and 7 do not contain Compound A and contain Compound B. The evaluation of phase separation for Comparative Examples 6 and 7 was "C". From this result, it was suggested that Compound A may contribute to the suppression of phase separation.

[0076] Among Comparative Examples 1 - 9, Comparative Examples 1, 2, 4, 5, 8, and 9 contained Compound A and did not contain Compound B. Although the evaluation of phase separation for Comparative Examples 1, 2, 4, 5, 8, and 9 was "A", the evaluation of fluidity was "C". From this result, it was suggested that Compound B could contribute to ensuring fluidity.

[0077] Among Examples 1 - 10, Examples 3 and 8 are compared. Example 3 is an example using glycerin (hydroxyl value 1830 mgKOH / g) as Compound B. Example 8 is an example using diglycerin (hydroxyl value 1352 mgKOH / g) as Compound B. The evaluation of fluidity and viscosity for Example 3 was "A", and the evaluation of fluidity and viscosity for Example 8 was "B". From this result, it was suggested that a higher hydroxyl value of Compound B could preferably ensure fluidity.

[0078] Among Examples 1 - 10, Example 10 further satisfies the following requirement (c). · Requirement (c): Further, it contains a polyol with a hydroxyl value of less than 150 mgKOH / g. Example 10, which further satisfies Requirement (c), had an overall determination of "A". Example 10 was able to obtain a polyurethane decomposition product that was even more easily usable as a recycled urethane raw material.

[0079] <Examples 11 - 16, Comparative Example 10> The overall determination for Examples 11 - 16 was "A" or "B". On the other hand, the overall determination for Comparative Example 10 was "C". It is considered that by using Compound A and Compound B in combination, a polyurethane decomposition product that is more easily usable as a recycled urethane raw material could be obtained compared to Comparative Example 10.

[0080] Compare Examples 11, 12, and 16, which are linear alkanediols and have the same compounding amounts of Compound A and Compound B. In Examples 11, 12, and 16, as the carbon number of the alkanediol increased from 3 to 10, the viscosity of the polyurethane decomposition product increased from 5,200 to 185,000. From this result, it was suggested that the smaller the carbon number of the alkanediol as Compound A, the more it can contribute to the reduction of viscosity.

[0081] 6. Effects of the Examples According to this example, a technique for easily obtaining a polyurethane decomposition product that is easy to use as a recycled urethane raw material could be provided. For example, according to this example, a polyurethane decomposition product with suppressed phase separation and high fluidity could be obtained.

[0082] The present disclosure is not limited to the examples detailed above, and various modifications or changes are possible within the scope of the present disclosure.

Claims

1. A composition for decomposing polyurethane, comprising compound A and compound B, The compound A is one or more compounds selected from the group consisting of polyethylene glycol represented by the following general formula (I), aminoalcohols having neither a primary amino group nor a secondary amino group, and alkanediols having 3 to 10 carbon atoms, The polyurethane decomposition composition, wherein the compound B is one or more compounds selected from the group consisting of glycerin and polyglycerin having a hydroxyl value of 1,150 mg KOH / g or more. P.S. ２ CH ２ O) ｎ H ・・・(I) (where n is an integer between 2 and 17)

2. The polyurethane decomposition composition according to claim 1 , which contains a tertiary amine compound having no hydroxyl group as a decomposition catalyst.

3. The polyurethane decomposition composition according to claim 1 or 2, further comprising a polyol having a hydroxyl value of less than 150 mgKOH / g.

4. A polyurethane decomposition product obtained by decomposing a polyurethane resin with the polyurethane decomposition composition according to claim 1 or 2.

5. A method for producing a polyurethane decomposition product, comprising decomposing a polyurethane resin with the polyurethane decomposition composition according to claim 1 or 2.

6. A method for decomposing a polyurethane resin, comprising decomposing the polyurethane resin by using the composition for decomposing a polyurethane according to claim 1 or 2.

Images