Laminate, interior member for vehicle, bedding, and disassembling method

Abstract

To provide a laminate, an interior member for vehicle and a bedding which can be disassembled under mild conditions, and a disassembling method.SOLUTION: A laminate is formed by laminating a first member and a second member via an adhesive layer having polymers including a structural unit represented by the following formula (1). (In the formula (1), Ra is any one of urethane bond, urea bond and thiourethane bond, R11 to R13 are each independently either one of hydrogen or monovalent organic group.)SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laminate, an interior member for a vehicle, a bedding, and a disassembling method.

Background Art

[0002] As an outer skin material covering the surface of interior members for vehicles such as vehicle seat cushions and bedding, a laminate in which a surface material is laminated on the surface of a soft polyurethane foam via an adhesive layer is used.

[0003] The above-described laminate has a problem that it is difficult to separate and disassemble or reuse after use due to, for example, the improvement of the performance of the adhesive layer. In order to solve such a problem, for example, a laminate using an adhesive that can be decomposed by heating has been disclosed (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technique of Patent Document 1, heat treatment at a high temperature of 220°C or higher is required for the decomposition of the epoxy resin composition used as an adhesive. Thus, in the conventional technique, a problem has been that a very high energy is required for the decomposition of polymers such as adhesives.

[0006] Therefore, an object of the present invention is to provide a laminate, an interior member for a vehicle, a bedding, and a disassembling method that can be disassembled under mild conditions.

Means for Solving the Problems

[0007] In one aspect, the present invention is a laminate. In the laminate, a first member and a second member are laminated via an adhesive layer having a polymer containing a structural unit represented by the following formula (1). [Chemical formula] (In formula (1), R a is any one of a urethane bond, a urea bond, or a thiourethane bond, and R 11 ~R 13 are each independently either hydrogen or a monovalent organic group.)

[0008] In the laminate of the above aspect, it is preferable that the adhesive layer is formed by curing an adhesive composition containing a urethane prepolymer.

[0009] Another aspect of the present invention is an interior member for a vehicle or a bedding. The interior member for a vehicle or the bedding includes the laminate of the above aspect.

[0010] Another aspect of the present invention is a method for disassembling the laminate of the above aspect. The disassembling method includes a step of subjecting the polymer contained in the laminate to base treatment after oxidation. [Advantages of the Invention]

[0011] According to the present invention, it is possible to provide a laminate, an interior member for a vehicle, a bedding, and a disassembling method that can be disassembled under mild conditions. [Brief Description of the Drawings]

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0013] In the following, when an upper limit value and a lower limit value are separately described, it is assumed that a numerical range obtained by combining any upper limit value and any lower limit value is substantially disclosed.

[0014] Also, when a certain compound is described, its isomers are also assumed to be described at the same time.

[0015] In the following, the number average molecular weight is measured using gel permeation chromatography (GPC) (for example, gel permeation chromatography according to ASTM standard test D5296) with polystyrene as the standard polymer.

[0016] In the following, each viscosity is an E-type viscosity measured in accordance with JIS Z8803:2011 "Method for Measuring Viscosity of Liquids". The measurement is performed using a cone-plate type rotational viscometer.

[0017] Unless otherwise specified, various measurements are carried out with the environmental temperature being room temperature (25°C).

[0018] 1. Laminate FIG. 4 is a schematic cross-sectional view schematically showing the laminate of the present embodiment. As shown in FIG. 4, the laminate 100 has a first member 10 and a second member 20 laminated via an adhesive layer 30.

[0019] The shape and size (thickness) of the laminate 100 (the first member 10 and the second member 20) are not particularly limited and can be appropriately adjusted according to the use of the laminate. The thickness of the adhesive layer 30 is preferably 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, 80 μm or more, 90 μm or more, 100 μm or more, 150 μm or more, 200 μm or more, etc., and preferably 400 μm or less, 350 μm or less, 300 μm or less, etc.

[0020] Hereinafter, each component of the laminate 100 will be described in detail.

[0021] 1-1. Adhesive layer The adhesive layer has a polymer containing a structural unit represented by the following formula (1).

Chemical formula

[0022] The polymer contained in the adhesive layer of the present embodiment is not particularly limited, and examples include polyurethane-based, polyurea-based, polythiourethane-based, etc. When the polymer is polyurethane-based, the adhesive layer is formed by curing an adhesive composition containing a urethane prepolymer described later.

[0023] The adhesive layer may contain other components in addition to the polymer. Hereinafter, components such as the polymer contained in the adhesive layer will be described.

[0024] 1-1-1. Polymer The polymer of the present embodiment has a structural unit represented by the above formula (1). R in formula (1) a may be the same bond or different bonds in each structural unit as long as it is any one of a urethane bond, a urea bond, or a thiourethane bond. Also, the polymer of the present embodiment may be linear or branched.

[0025] The polymer of this embodiment has a first organic group and a second organic group that bind to the structural unit represented by the above formula (1). The first organic group and the second organic group are not particularly limited, and may be, for example, hydrocarbon groups, or organic groups containing oxygen, fluorine, sulfur, nitrogen, phosphorus, chlorine, etc. The first organic group and the second organic group may have the same structure or different structures. The number average molecular weight of the first organic group and the second organic group when decomposition treatment (alkali treatment after oxidation) is performed by the decomposition method described later is preferably 1,000 or more, more preferably 1,100 or more, and still more preferably 1,200 or more.

[0026] The polymer of this embodiment is preferably composed of repeating structural units represented by the following formula (2).

Chemical formula

[0027] In formula (2), R a is any one of a urethane bond, a urea bond, or a thiourethane bond, and R 11 ~R 13 are each independently either hydrogen or a monovalent organic group, and R1 is a divalent organic group.

[0028] Among the structural units represented by the above formula (2) in the polymer of this embodiment, when decomposition treatment (alkali treatment after oxidation) is performed by the decomposition method described later, the number average molecular weight of R1 is preferably 1,000 to 10,000, more preferably 1,100 to 9,000, and still more preferably 1,200 to 8,000 or less.

[0029] The polymer of the present embodiment is preferably obtained by polymerizing (curing) a prepolymer obtained by reacting an active hydrogen compound having two or more active hydrogen groups such as a polyol compound, a polyamine compound, or a polythiol compound, and a polyisocyanate compound, and a compound (A) described later. That is, when the prepolymer is obtained by reacting a polyol compound and a polyisocyanate compound, the polyurethane of the present embodiment is obtained. When the prepolymer is obtained by reacting a polyamine compound and a polyisocyanate compound, the polyurea of the present embodiment is obtained. Further, when the prepolymer is obtained by reacting a polythiol compound and a polyisocyanate compound, the polythiourethane of the present embodiment is obtained.

[0030] The polymer of the present embodiment thus obtained preferably has a decomposition rate of 5% or more, more preferably 30% or more, and even more preferably 50% or more when subjected to decomposition treatment (alkali treatment after oxidation) by the decomposition method described later.

[0031] As described above, the polymer of the present embodiment contains polymers such as polyurethane, polyurea, or polythiourethane. Hereinafter, polyurethane will be taken as an example of a typical embodiment among the polymers to describe the physical properties / characteristics of the polymer of the present embodiment. However, the polymer of the present embodiment is not limited to polyurethane. The raw material composition and production method of the polymer will be described in "2. Raw Material Composition / Production Method of Polymer" described later.

[0032] <Physical Properties / Characteristics> (Decomposition Performance) The polyurethane of this form undergoes a decomposition reaction proceeding from the decomposition method described later. That is, the polyurethane of this form has decomposition performance under a certain environment. The decomposition performance, that is, the degree of progress of the decomposition reaction can be evaluated by the gel fraction / decomposition rate described later. Note that since the decomposition reaction does not proceed during normal use at room temperature and normal pressure for the polyurethane of this form, it is superior in physical properties, mechanical properties, and chemical properties compared to conventional degradable polymers. Also, since the decomposition process described later is under mild conditions and a simple treatment, it does not require high energy for decomposition.

[0033] (Decomposition process) Add a solvent and an oxidizing agent to the polyurethane and stir at room temperature for 1 hour to 20 hours. Take out the polyurethane, add an aqueous base solution, and stir at room temperature for 1 minute to 20 hours.

[0034] The solvent used in the decomposition process is not particularly limited, and known ones can be used. For example, distilled water, DMSO (dimethyl sulfoxide), DMF (N,N-dimethylformamide), etc. can be mentioned.

[0035] (Decomposition mechanism) Figure 1 shows the mechanism of the decomposition reaction of the polyurethane of this form. As shown in Figure 1, for the polyurethane of this form, when an oxidizing agent is added, the sulfur atom of the thioether group is oxidized. Then, when an aqueous base solution is added and base treatment is performed, the polymer main chain of the polyurethane is cleaved and the decomposition reaction proceeds. At least a part of the polyurethane after the decomposition reaction dissolves in the aqueous base solution. Here, the decomposition mechanism of the polyurethane of this form has been described, but this decomposition mechanism is not limited to the polyurethane of this form. That is, this decomposition mechanism is similarly applicable to the cases of polyureas and polythiourethanes.

[0036] The oxidizing agent is not particularly limited, and examples thereof include hydrogen peroxide, OXONE (registered trademark) (potassium peroxymonosulfate), peracetic acid, sodium hypochlorite, sodium perborate, and the like. It is necessary to add 1 equivalent or more of the oxidizing agent to the thioether group of the polyurethane of this form. The aqueous base solution is not particularly limited, and examples thereof include strong bases such as an aqueous sodium hydroxide solution and an aqueous potassium carbonate solution, and weak bases such as an aqueous sodium carbonate solution.

[0037] (Gel fraction / decomposition rate) Before and after the decomposition reaction by the above decomposition method, the mass of the polyurethane is measured by the measurement method described later, and the gel fractions before and after the decomposition reaction are calculated respectively. Further, the decomposition rate is calculated from the gel fractions before and after the decomposition reaction. From the values of the gel fraction and the decomposition rate, the progress of the decomposition reaction of the polyurethane, that is, the decomposition performance, can be evaluated.

[0038] (Measurement method of polyurethane mass) First, the mass of the polyurethane is measured before performing the drying treatment described later. Then, the following drying treatment is performed. Add tetrahydrofuran (THF) to the polyurethane and stir at room temperature for 20 hours. Take out the polyurethane, heat it to 50 °C while evacuating to remove tetrahydrofuran, and dry it. Measure the mass of the polyurethane after the above-described drying treatment.

[0039] (Calculation method of gel fraction / decomposition rate) The mass of the polyurethane after the drying treatment obtained by the above-described measurement method is divided by the mass of the polyurethane before the drying treatment to obtain the gel fraction. The value obtained by subtracting the gel fraction after decomposition from the gel fraction before decomposition is divided by the gel fraction before decomposition to obtain the decomposition rate. The calculation formulas for the gel fraction and the decomposition rate are shown below. (Gel fraction) = (mass after drying treatment) / (mass before drying treatment) × 100 (Decomposition rate) = {(gel fraction before decomposition) - (gel fraction after decomposition)} / (gel fraction before decomposition) × 100

[0040] The gel fraction before decomposition is not particularly limited and is measured for calculating the decomposition rate. The gel fraction after decomposition is preferably 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, or 15% or less. Also, the decomposition rate is preferably 5% or more, 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more. By the gel fraction and the decomposition rate being within the above ranges, the decomposition of the polyurethane can proceed sufficiently.

[0041] The polyurethane of this form can control the number average molecular weight of the decomposition product and achieve the gel fraction and decomposition rate within the above ranges by being produced by the production method (prepolymer method) described later. The number average molecular weight of the decomposition product will be described below.

[0042] (Number average molecular weight of the decomposition product) For the polyurethane of this form, the number average molecular weight of the decomposition product after performing the above-described decomposition experiment is preferably 1,000 to 10,000, 1,100 to 9,000, or 1,200 to 8,000. The number average molecular weight of the decomposition product can be equivalent to the number average molecular weight of the urethane prepolymer used in the raw material composition.

[0043] 1-1-2. Other components The adhesive layer of this embodiment can contain other components (for example, various additives) as necessary in addition to the above-described polymer. Examples of the additives include oil components (plasticizers), tackifiers, antioxidants, waxes, heat stabilizers, fillers, pigments, dyes, antistatic agents, flame retardants, antibacterial agents, light stabilizers, dispersants, solvents, etc.

[0044] Examples of the oil component include paraffinic oil, naphthenic oil, and aromatic oil. Note that vegetable oil or the like may be used as the oil component.

[0045] The tackifier can exemplify one or more tackifying resins selected from the group consisting of aliphatic petroleum resins, aromatic petroleum resins, hydrogenated aliphatic petroleum resins, hydrogenated aromatic petroleum resins, terpene resins, styrene resins, rosin resins, and modified resins thereof.

[0046] Examples of the antioxidant include phenolic antioxidants {e.g., Irganox 1010 (manufactured by BASF)}, sulfur antioxidants (e.g., SUMILIZER TP-D (manufactured by Sumitomo Chemical)), and phosphorus antioxidants (e.g., Irgafos 168 (manufactured by BASF), JP-650 (manufactured by Johoku Chemical)).

[0047] Examples of the wax include natural waxes {e.g., animal waxes (such as beeswax and whale wax), plant waxes (such as wood wax), petroleum waxes (such as paraffin wax), etc.}, and synthetic waxes {e.g., synthetic hydrocarbons (such as low molecular weight polyethylene), fatty acid esters (such as polyethylene glycol), etc.}.

[0048] These additives may be used alone or in combination of two or more.

[0049] 1-2. First Member / Second Member The materials, shapes, and sizes (thicknesses) used for the first member and / or the second member of this embodiment are not particularly limited and can be appropriately selected according to the use of the laminate of this embodiment. For example, when the laminate is used as an interior member for a vehicle, the first member and the second member will each function as a base material for the interior member of the vehicle and a skin material that constitutes the design surface of the interior member of the vehicle, respectively.

[0050] Therefore, for example, if the first member is a base material, it is preferably made of a material having cushioning properties, such as olefin-based materials such as polyethylene and polypropylene, foams such as polyurethane and polystyrene. Also, if the second member is a skin material, appropriate materials made of, for example, genuine leather, synthetic leather, or fabric can be mentioned according to the decorativeness, touch, etc.

[0051] The first member and the second member may be formed of different materials or the same material. In this embodiment, since the adhesive layer contains the polymer described above, the laminate can be disassembled under mild conditions. Therefore, even if the first member and the second member are formed of different materials, they can be easily separated and disassembled when the laminate is discarded or reused after use.

[0052] 2. Raw material composition / production method of polymer (polyurethane) Hereinafter, the raw material composition and production method of the polymer (polyurethane) of this embodiment will be described. As described above, the polymer of this embodiment is not limited to polyurethane. That is, by changing the polyol compound, which is the raw material composition of the following polymer (polyurethane), to a polyamine compound or a polythiol compound, a polyurea or a polythiourethane can be produced.

[0053] 2-1. Raw material composition of polymer (polyurethane) The polymer (polyurethane) of this form is obtained by polymerizing (curing) a raw material composition containing an isocyanate group-terminated urethane prepolymer and a compound (A) having a structure represented by the following formula (3). Further, the polyurethane of this form may contain other components in the raw material composition. Hereinafter, the urethane prepolymer, the compound (A), and other components, which are the raw material composition of the polyurethane of this form, will be described.

[0054]

Chemical formula

[0055] In formula (3), R A , R B are each independently either a hydroxyl group, an amino group, or a thiol group, and R 11 to R 13 are each independently either hydrogen or a monovalent organic group, and R2 is a divalent organic group.

[0056] <Urethane prepolymer> The urethane prepolymer is obtained by subjecting a polyol compound and a polyisocyanate compound to a urethane reaction. In other words, the urethane prepolymer is a reaction product of a polyol compound and a polyisocyanate compound. More specifically, the urethane prepolymer is usually obtained by subjecting a polyol compound and a polyisocyanate compound to a urethane reaction such that the polyisocyanate compound is in excess, and a urethane prepolymer having an isocyanate group terminal is synthesized.

[0057] The number average molecular weight of the urethane prepolymer is preferably 1,000 to 10,000, 1,100 to 9,000, or 1,200 to 8,000. The molecular weight (calculated value) (the calculation method will be described in detail in the examples) of the urethane prepolymer is preferably 1,000 to 5,000, 1,100 to 4,000, or 1,200 to 3,000. By having the number average molecular weight and the molecular weight (calculated value) of the urethane prepolymer within the above ranges, a polyurethane having more excellent decomposition performance can be obtained.

[0058] The viscosity of the urethane prepolymer at 25°C is preferably 2,000 to 50,000 mPa·s, 2,000 to 40,000 mPa·s, 2,500 to 20,000 mPa·s, 3,000 to 10,000 mPa·s, or 3,500 to 6,000 mPa·s. By having the viscosity of the urethane prepolymer at 25°C within the above ranges, a polyurethane having more excellent decomposition performance can be obtained.

[0059] (Polyol compound) The polyol compound is a compound having two or more hydroxyl groups in one molecule. The polyol compound is not particularly limited. Various polyols may be used alone or in combination of two or more. It can be freely selected in consideration of the desired properties of the polyurethane.

[0060] The polyol compound preferably contains a copolymer (preferably, a random copolymer) of ethylene oxide (EO) and an alkylene oxide (AO). Herein, the alkylene oxide indicates those other than ethylene oxide.

[0061] Examples of the polyol compound include polyester polyol, polycarbonate polyol, polyether polyol, polyester ether polyol, etc. It can be freely selected in consideration of the desired polyurethane properties.

[0062] Examples of the polyester polyol include those obtained by dehydration condensation reaction of aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid; aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and naphthalene dicarboxylic acid; alicyclic dicarboxylic acids such as hexahydrophthalic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid; or their acid esters or acid anhydrides with ethylene glycol, 1,3 - propylene glycol, 1,2 - propylene glycol, 1,3 - butanediol, 1,4 - butanediol, 1,5 - pentanediol, 1,6 - hexanediol, 3 - methyl - 1,5 - pentanediol, neopentyl glycol, 1,8 - octanediol, 1,9 - nonanediol, etc., or their mixtures; polyester polyols such as polypropylene glycol; and polylactone diols obtained by ring - opening polymerization of lactone monomers such as ε - caprolactone and methyl valerolactone.

[0063] Examples of the polycarbonate polyol include those obtained by reacting at least one polyhydric alcohol such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, diethylene glycol with diethylene carbonate, dimethyl carbonate, diethyl carbonate, or the like.

[0064] Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc. obtained by polymerizing cyclic ethers such as ethylene oxide (EO), propylene oxide (PO), and tetrahydrofuran respectively, and copolymers thereof. Also, they can be obtained by polymerizing the above cyclic ethers using polyhydric alcohols such as glycerin and trimethylolethane.

[0065] Examples of the polyester ether polyol include those obtained by a dehydration condensation reaction of an aliphatic dicarboxylic acid such as succinic acid, adipic acid, sebacic acid, and azelaic acid, an aromatic dicarboxylic acid such as phthalic acid, terephthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, an alicyclic dicarboxylic acid such as hexahydrophthalic acid, hexahydroterephthalic acid, and hexahydroisophthalic acid, or acid esters or acid anhydrides thereof with a glycol such as diethylene glycol or a propylene oxide adduct, or a mixture thereof.

[0066] The polyol compound can be used alone or in combination of a plurality.

[0067] The polyol compound is preferably a diol and / or a triol.

[0068] The polyol compound preferably has a number average molecular weight of 200 to 5,000, 300 to 4,500, or 400 to 4,000. When the number average molecular weight of the polyol is within such a range, the number average molecular weight of the urethane prepolymer is included in an appropriate range, so that a polyurethane having more excellent decomposition performance can be obtained.

[0069] (Polyisocyanate compound) The polyisocyanate compound is a compound having two or more isocyanate groups in one molecule. It is not particularly limited as long as it is commonly used as a raw material for urethane prepolymers. The polyisocyanate compound may be used alone or in combination of two or more. The polyisocyanate compound may be bifunctional or trifunctional or higher. It can be freely selected in consideration of the desired properties of the polyurethane.

[0070] Examples of the bifunctional polyisocyanate compound include aromatic compounds such as 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), 2,2'-diphenylmethane diisocyanate (2,2'-MDI), hydrogenated MDI, xylylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, polymethylene polyphenyl polyisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, tetramethylxylylene diisocyanate (TMXDI); alicyclic compounds such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, methylcyclohexane diisocyanate; and alkylene compounds such as butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, lysine diisocyanate, etc.

[0071] Examples of the polyisocyanate compound having a functionality of 3 or more include 1-methylbenzene-2,4,6-triisocyanate, 1,3,5-trimethylbenzene-2,4,6-triisocyanate, biphenyl-2,4,4'-triisocyanate, diphenylmethane-2,4,4'-triisocyanate, methyldiphenylmethane-4,6,4'-triisocyanate, 4,4'-dimethyldiphenylmethane-2,2',5,5'-tetraisocyanate, triphenylmethane-4,4',4''-triisocyanate, polymeric MDI, lysine ester triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,6,11-undecane triisocyanate, bicycloheptane triisocyanate, 1,8-diisocyanatomethyloctane, etc.

[0072] Furthermore, the polyisocyanate compound can include these modified products, derivatives, and the like.

[0073] The polyisocyanate compound can be used alone or in combination of a plurality thereof.

[0074] <Compound (A)> Compound (A) has a structure represented by the following formula (3). [Chemical formula]

[0075] In formula (3), R A , R B are each independently an active hydrogen group (any one of a hydroxyl group, an amino group, or a thiol group), and R 11 to R 13 are each independently either hydrogen or a monovalent organic group, and R2 is a divalent organic group.

[0076] As shown by the above formula (3), Compound (A) has an active hydrogen group capable of reacting with an isocyanate group at the ends (R A , R B ) of the molecular chain. Compound (A) preferably contains a thioether group.

[0077] Examples of the active hydrogen group at the ends (R A , R B ) of the molecular chain include, for example, a hydroxyl group, an amino group, a thiol group, etc. Preferably, a hydroxyl group and an amino group are included, and more preferably, a hydroxyl group is included. The ends (R A , R B ) of the molecular chain may be the same type of functional group or a combination of different types of functional groups. Note that the amino group is preferably a primary amino group. Furthermore, Compound (A) may also have an active hydrogen group in a portion other than the ends (R A , R B ) of the molecular chain. That is, Compound (A) may have three or more active hydrogen groups.

[0078] R2 is not particularly limited as long as it is a divalent organic group, preferably a hydrocarbon group having 1 to 19 carbon atoms, more preferably 1 to 10 carbon atoms, still more preferably 1 to 5 carbon atoms, and most preferably 2 carbon atoms.

[0079] R 11 ~R 13 is not particularly limited as long as it is hydrogen or a monovalent organic group, preferably hydrogen or a hydrocarbon group having 1 to 5 carbon atoms, and more preferably hydrogen.

[0080] The number of carbon atoms per sulfur atom bonded to R A -C-C- and R2 in the compound (A) is preferably, for example, 2 or more, more preferably 3 or more, and preferably 7 or less, more preferably 4 or less.

[0081] More specifically, examples of the compound (A) include a hydroxyl group-terminated thioether group-containing compound, an amino group-terminated thioether group-containing compound, and a thiol group-terminated thioether group-containing compound.

[0082] The hydroxyl group-terminated thioether group-containing compound has a hydroxyl group at the terminal (R A , R B ) of the molecular chain and a thioether group in the middle of the molecular chain. Examples of the hydroxyl group-terminated thioether group-containing compound include 2,2'-thiodiethanol (TDE).

[0083] The amino group-terminated thioether group-containing compound has an amino group at the terminal (R A , R B ) of the molecular chain and a thioether group in the middle of the molecular chain. Examples of the amino group-terminated thioether group-containing compound include bis(2-aminoethyl) sulfide.

[0084] The thiol group-terminated thioether group-containing compound has a thiol group at the terminal (R A , R B) has a thiol group and has a thioether group in the middle of the molecular chain. Examples of the thiol group-terminated thioether group-containing compound include bis(2-mercaptoethyl)sulfide (MES) and the like.

[0085] The content of compound (A) is preferably 1% by mass or more, 5% by mass, 10% by mass or more, etc., based on the mass of the urethane prepolymer, and is preferably 25% by mass or less, 20% by mass or less, 15% by mass or less, etc.

[0086] The molecular weight of compound (A) is preferably 50 or more, 60 or more, 100 or more, etc., and is preferably 500 or less, 400 or less, 300 or less.

[0087] The sulfide concentration in 1 kg of the polyurethane of this form is preferably 0.1 mol / kg or more, 0.2 mol / kg or more, 0.3 mol / kg or more, etc., and is preferably 0.9 mol / kg or less, 0.85 mol / kg or less, 0.8 mol / kg or less, etc. The calculation method of the sulfide concentration will be described below.

[0088] (Calculation method of sulfide concentration) From the number of input portions of compound (A) and the total number of all components of the polyurethane of this form, the content P of compound (A) in 1 kg of the polyurethane is calculated. The content P of this compound (A) is divided by the molecular weight Q of compound (A) to calculate the sulfide concentration in 1 kg of the polyurethane. The calculation formula of the sulfide concentration is shown below. (Sulfide concentration) = {Content P of compound (A)} / {Molecular weight Q of compound (A)} (mol / kg)

[0089] In the raw material composition of the polyurethane of this form, if the blending amount of compound (A) and the sulfide concentration are within the above-mentioned ranges, it may contain another compound (B) other than compound (A). Compound (B) is not particularly limited as long as it is a compound polymerizable with the urethane prepolymer, and examples thereof include diethylene glycol, 1,5-pentanediol, and the like.

[0090] <Other components> Examples of other components that can be appropriately added to the raw material composition of the polyurethane in this form include defoaming agents, catalysts, and the like.

[0091] (Defoaming agent) As the defoaming agent, for example, fatty acid esters, petrolatum, etc. can be used. The foam stabilizer / defoaming agent may be any one of these, or two or more of them may be used in combination.

[0092] (Catalyst) The catalysts include tertiary amines {C6-20, such as triethylamine, triethylenediamine, bis(dimethylaminoethyl)ether, N-methylmorpholine, dimethylaminomethylphenol, N-methyl-N-dimethylaminoethylpiperazine, pyridine, etc.}, and acid-blocking compounds thereof, metal salts of carboxylic acids (C2-20) (sodium acetate, lead octylate, zinc octylate, iron octylate, bismuth octylate, zinc neodecanoate, iron naphthenate, cobalt naphthenate, stannous octoate, dibutyltin dilaurate, etc.), alkoxides or phenoxides of alkali metals or alkaline earth metals (C1-12, such as sodium methoxide, sodium phenoxide), quaternary ammonium salts (C4-12, such as tetraethylhydroxylammonium), imidazole compounds (C3-12, such as imidazole, 2-ethyl-4-methylimidazole), chelate metal salts (C5-20, such as zinc acetylacetonate, iron acetylacetonate), and organometallic compounds containing metals such as tin and antimony (C3-30, such as tetraphenyltin, tributylantimony oxide), etc. These catalysts can be used alone or in combination.

[0093] 2-2. Method for producing polymer (polyurethane) The polymer (polyurethane) of this form can be produced based on the prepolymer method. The prepolymer method of this form is a method in which a part of each of a polyol compound and a polyisocyanate compound is reacted in advance to obtain a prepolymer having an isocyanate group at the terminal (the urethane prepolymer described above), and then the compound (A) is reacted therewith.

[0094] Figure 2 shows the flow of the method for producing the polyurethane of this form. As shown in Figure 2, the method S1 for producing the polyurethane of this form has a urethane prepolymer production step S10, a raw material composition preparation step S20, and a curing step S30. Hereinafter, the preferred production method S1 of the polyurethane of this form will be described by dividing it into each step.

[0095] 2-2-1. Urethane prepolymer production step S10 A predetermined amount of a polyol compound and, if necessary, a catalyst are dropped into a reaction vessel containing a predetermined amount of a polyisocyanate compound. Then, the inside of the reaction vessel is heated and stirred to react the polyisocyanate compound with the polyol compound to produce a urethane prepolymer having an isocyanate group at the terminal. The reaction temperature is not particularly limited, but is usually 50 to 120 °C, preferably 60 to 100 °C. The reaction time is not particularly limited, but is usually 1 to 15 hours.

[0096] Regarding the polyol compound, polyisocyanate compound, etc., they are as described in the above-mentioned (polyol compound), (polyisocyanate compound).

[0097] (Catalyst) As the catalyst, known ones used in the production of polyurethane can be used. For example, amine-based catalysts, organometallic-based catalysts, etc. can be mentioned.

[0098] Examples of amine-based catalysts include triethylenediamine, diethanolamine, dimethylaminomorpholine, N-ethylmorpholine, etc.

[0099] Examples of the organometallic catalyst include bismuth carboxylate, stannous octoate, dibutyltin dilaurate, lead octenoate, potassium octylate, and the like.

[0100] The catalyst can be used alone or in combination of a plurality thereof.

[0101] 2-2-2. Preparation Step S20 of Raw Material Composition In the preparation step S20 of the raw material composition, as the raw material composition, a urethane prepolymer and, as the compound (A), a raw material composition containing, for example, 2,2'-thiodiethanol are prepared. The raw material composition may contain other components (such as a catalyst and an antifoaming agent) as necessary. The urethane prepolymer, the compound (A), and other components are as described in the above-mentioned "2-1. Raw Material Composition of Polymer (Polyurethane)".

[0102] 2-2-3. Curing Step S30 FIG. 3 is a diagram showing the flow of the curing step S30. As shown in FIG. 3, the curing step S30 includes mixing and stirring the raw material composition prepared in the preparation step S20 of the raw material composition (stirring step S31), charging (injecting) the raw material composition into a reaction vessel (mold) (charging step S32), and heating the raw material composition as necessary to complete the polymerization (curing) reaction to produce polyurethane (reaction step S33). Hereinafter, the curing step S30 will be described by dividing it into each step.

[0103] (Stirring Step S31) In the stirring step S31, the urethane prepolymer, which is the raw material composition prepared in the preparation step S20 of the raw material composition, the compound (A), for example, 2,2'-thiodiethanol, and other components such as a catalyst and an antifoaming agent are put into a container such as a disposable cup and stirred so that each component is uniformly mixed. The stirring step S31 can be carried out using known stirring means such as a mixer. The stirring conditions of the stirring step S31 may be appropriately selected according to the viscosity of the raw material composition, the components to be blended, and the like.

[0104] (Charging Step S32) In the charging step S32, the raw material composition mixed in the stirring step S31 is charged (injected) into a reaction vessel or the like. When a mold is used as the reaction vessel, by making the cavity of the mold into the product shape, a polyurethane having a desired product shape according to the application can be obtained without performing post-processing. Further, when the raw material composition is used as an adhesive composition as in the laminate of the present embodiment, it may be attached to the surface of the member to be adhered (the first member or the second member).

[0105] (Reaction step S33) In the reaction step S33, the raw material composition charged into the reaction vessel in the charging step S32 is heated and cured. Usually, it is carried out at a temperature of 15 to 120°C, preferably 15 to 90°C. The reaction time is usually 60 to 120 minutes.

[0106] A drying step may be performed on the cured product obtained in the reaction step S33, if necessary. Examples of the drying step include a method of exposing the polyurethane to an environment of 80 to 120°C using a heating furnace, a microwave oven, high-frequency induction heating, hot air drying, or the like. Note that the above-described charging step S32 and reaction step S33 may be carried out in the heat treatment in the "3. Method for manufacturing a laminate" described later.

[0107] 3. Method for manufacturing a laminate As a method for manufacturing the laminate of the present embodiment, first, the above-described adhesive composition is provided in a scattered state on the adhesion surface of either the first member (for example, soft polyurethane foam (PUF)) or the second member (for example, synthetic leather). Next, the PUF and the synthetic leather are laminated with the adhesive composition sandwiched therebetween, and heated and pressed in the laminated state to cure the adhesive composition to form an adhesive layer. Alternatively, after forming a film of the adhesive composition on the release-treated PET film, the surface of the PUF is placed on the formed film of the adhesive composition, and the PUF is bonded to the synthetic leather so that the adhesive side of the PUF contacts the synthetic leather, and then heated to cure the adhesive composition.

[0108] 4. Method for disassembling the laminate As a method for disassembling the laminate of the present embodiment, it includes a step of subjecting the polymer (polyurethane) contained in the laminate to base treatment after oxidation. More specifically, it is as follows. According to the following disassembly method, disassembly is possible under mild conditions.

[0109] (Disassembly method) Add a solvent and an oxidizing agent to the laminate, and stir at room temperature for 1 hour to 20 hours. Take out the laminate, add an aqueous base solution, and stir at room temperature for 1 minute to 20 hours.

[0110] The solvent used in the disassembly step is not particularly limited, and known solvents can be used. For example, distilled water, DMSO (dimethyl sulfoxide), DMF (N,N-dimethylformamide), etc. can be mentioned.

[0111] 5. Applications of the laminate The laminate of this embodiment can be used, for example, for interior members such as vehicle seat cushions, bedding, furniture, clothing, shoes, bags, etc.

Examples

[0112] Examples are shown below to more specifically explain the present invention. However, the present invention is not limited to these examples, and can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art.

[0113] ≪Raw material composition of the adhesive layer (polymer)≫ ● Urethane prepolymer with isocyanate group terminals Urethane prepolymer A (number average molecular weight: 1,550) and urethane prepolymer B (number average molecular weight: 1,600) produced with the compounding components and compounding ratios described in Tables 1 and 2 below

[0114]

Table 1

Table 2

[0115] ●Compound (A) 2,2'-Thiodiethanol (molecular weight: 122.2) ●Compound (B) Diethylene glycol (molecular weight: 106.1)

[0116] ●Other components Defoaming agent {DAPPO (registered trademark), manufactured by San Nopco Ltd.} Catalyst {TIB KAT616 Zn-based (manufactured by TIB Chemicals)}

[0117] <Examples and Comparative Examples> At the compounding ratios shown in Table 3 below, the raw material composition of the above adhesive layer was weighed into a container such as a disposable cup, and then stirred at room temperature for 1 minute with a propeller stirrer at 600 rpm. Next, it was defoamed under vacuum for 1 minute using a rotation-revolution mixer {Avatori Rentaro, manufactured by Shin Kee Co., Ltd.}. The raw material composition was poured onto a release-treated PET film, and a film was formed to a thickness of 250 μm using a knife coater to form an adhesive composition. A size of 50 mm × 50 mm, the surface of a soft polyurethane foam (PUF) (EL-45, manufactured by Inoac Corporation) was placed on the formed film of the adhesive. The PUF was lifted up, and after confirming that the adhesive was attached to the surface, it was placed so that the skin material (PET fabric) contacted the surface of the PUF with the adhesive, and a load was applied to bond them. They were left standing in a constant temperature bath at 70°C for 3 hours to be heated, and laminates of each example and comparative example in which the PUF and the skin material were laminated via the adhesive layer were produced.

[0118] All the adhesive layers (polyurethane) had an isocyanate index of 100. The isocyanate index refers to the ratio of the number of moles of isocyanate groups in the isocyanate compound (isocyanate-terminated urethane prepolymer) to the number of moles of thiodiethanol or diethylene glycol.

[0119] Based on the above-described calculation method, the sulfide concentration was calculated.

[0120]

Table 3

[0121] ≪Decomposition process≫ (Solvent) In the decomposition process, distilled water, DMSO (dimethyl sulfoxide), and DMF (N,N-dimethylformamide) were used as solvents. The types and mixing ratios of the solvents used in the decomposition process for the laminates of each example and comparative example are shown in Table 4 below. (Oxidation treatment) To a 300-ml vial containing the laminates of each example and comparative example, 3 equivalents of an oxidizing agent {OXONE (registered trademark) (potassium peroxymonosulfate)} with respect to the thioether group and the above solvent were added. The mixture was stirred with a roller stirrer at room temperature for 20 hours. The laminate was taken out of the solvent and washed with distilled water. (Base treatment) The laminate washed with distilled water was placed in a 300-ml vial, and 9 g of a 1 mol / L aqueous sodium hydroxide solution and the above solvent were added. The mixture was stirred with a roller stirrer at room temperature for 1 hour.

[0122] ≪Evaluation≫ For the laminates of each example and comparative example, after the above-described decomposition process, it was evaluated whether they were disassembled. The evaluation results of each example and comparative example are shown in Table 4 below. (Evaluation criteria) A: The PUF and the skin material are separated. B: The PUF and the skin material are not separated.

[0123] [Table 4] ※The compounding amounts in Table 4 are shown in mass %. [Industrial Applicability]

[0124] Since the laminate, interior member for vehicle, bedding, and disassembling method of the present invention can be disassembled under mild conditions, they can be used for interior members such as seat cushions of vehicles, bedding, furniture, clothing, shoes, bags, etc.

Claims

1. A laminate in which a first member and a second member are laminated via an adhesive layer having a polymer containing a structural unit represented by the following formula (1). 【Chemical 1】 (In formula (1), R ａ is any one of a urethane bond, a urea bond, or a thiourethane bond, and R １１ to R １３ are each independently either hydrogen or a monovalent organic group.)

2. The laminate according to claim 1, wherein the adhesive layer is formed by curing an adhesive composition containing a urethane prepolymer.

3. An interior member for a vehicle or a bedding, comprising the laminate according to claim 1 or 2.

4. A method for disassembling the laminate according to claim 1 or 2, the method comprising a step of subjecting the polymer contained in the laminate to base treatment after oxidation.

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