Aqueous coating agent and roof skin material for vehicle

Abstract

To disclose an aqueous coating agent that balances adhesiveness with flexibility.SOLUTION: An aqueous coating agent of the present disclosure comprises a polyester copolymer. The polyester copolymer comprises a polyvalent carboxylic acid residue and a polyvalent alcohol residue. The polyvalent carboxylic acid residue comprises a terephthalic acid residue and a metal sulfonate group-containing polyvalent carboxylic acid residue. The polyvalent alcohol residue comprises a polyethylene glycol residue having number average molecular weight of 800 or more and 6000 or less. The average proportion of the terephthalic acid residue in the polyvalent carboxylic acid residues contained in the polyester copolymer is 73 mass% or more and 99 mass% or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present application discloses an aqueous coating agent and a ceiling skin member for vehicles.

Background Art

[0002] From the perspective of environmental consideration, there is a high demand for improving the recyclability of environmentally friendly packages (materials) by using single materials. A vehicle ceiling material includes a base material and a skin material, and these materials are integrally molded in a laminated state. Usually, the skin material is laminated with a back coating material such as an acrylic resin for preventing fraying on a polyester fabric, a foamed material (soft polyurethane foam) of a polyurethane resin for imparting elasticity, and a non-woven fabric such as natural and synthetic fiber spunlace as a backing fabric. At present, the skin material has no recyclability because the materials used are different, and it is being discarded.

[0003] Patent Document 1 discloses an aqueous polyester resin having a terephthalic acid residue derived from recycled polyester and a polyvalent carboxylic acid residue other than the terephthalic acid residue, wherein the polyvalent carboxylic acid residue includes a polyvalent carboxylic acid residue containing a metal sulfonate group and another polyvalent carboxylic acid residue other than the terephthalic acid residue and the polyvalent carboxylic acid residue containing a metal sulfonate group, and the proportion of the terephthalic acid residue is 20% by mass or more and 72% by mass or less, and the proportion of the polyvalent carboxylic acid residue containing a metal sulfonate group is 5% by mass or more and 32% by mass or less, based on all the polyvalent carboxylic acid residues contained in the aqueous polyester resin, and the acid value is 10 mgKOH / g or less. Although the aqueous polyester resin has excellent adhesiveness, there is a problem that it impairs the flexibility of the base material.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] This application discloses an aqueous coating agent that achieves both adhesiveness and flexibility, and a ceiling skin member for a vehicle configured using the aqueous coating agent.

Means for Solving the Problems

[0006] As means for solving the above problems, this application discloses the following multiple aspects. <Aspect 1> An aqueous coating agent containing a polyester copolymer, wherein the polyester copolymer contains a polyvalent carboxylic acid residue and a polyhydric alcohol residue, the polyvalent carboxylic acid residue contains a terephthalic acid residue and a polyvalent carboxylic acid residue containing a metal sulfonate group, the polyhydric alcohol residue contains a polyethylene glycol residue having a number average molecular weight of 800 or more and 6000 or less, the average proportion of the terephthalic acid residue in the polyvalent carboxylic acid residue contained in the polyester copolymer is 73% by mass or more and 99% by mass or less, aqueous coating agent. <Aspect 2> The aqueous coating agent according to Aspect 1, wherein the polyester copolymer has a weight average molecular weight of 5000 or more and 50000 or less. aqueous coating agent. <Aspect 3> The aqueous coating agent according to Aspect 1 or 2, having a viscosity of 5000 mPa·s or more and 50000 mPa·s or less at 20°C. aqueous coating agent. <Aspect 4> A ceiling skin member for a vehicle having a polyester knitted fabric and a polyester nonwoven fabric, wherein the polyester knitted fabric and the polyester nonwoven fabric are laminated via the polyester copolymer contained in the aqueous coating agent according to any one of Aspects 1 to 3. Ceiling skin member for vehicle.

Effect of the Invention

[0007] The aqueous coating agent of the present disclosure is excellent in both adhesiveness and flexibility. When a ceiling skin member for a vehicle is configured using the aqueous coating agent of the present disclosure, it becomes easy to reduce the weight and make it a single material of the member.

Mode for Carrying Out the Invention

[0008] Hereinafter, an aqueous coating agent and a ceiling skin member for a vehicle according to an embodiment will be described, but the technology of the present disclosure is not limited to this embodiment.

[0009] 1. Aqueous coating agent The aqueous coating agent according to one embodiment contains a polyester copolymer. Here, the polyester copolymer contains a polyvalent carboxylic acid residue and a polyhydric alcohol residue. The polyvalent carboxylic acid residue contains a terephthalic acid residue and a polyvalent carboxylic acid residue containing a metal sulfonate group. The polyhydric alcohol residue contains a polyethylene glycol residue having a number average molecular weight of 800 or more and 6000 or less. The average ratio of the terephthalic acid residue in the polyvalent carboxylic acid residue contained in the polyester copolymer is 73% by mass or more and 99% by mass or less.

[0010] 1.1 Polyester copolymer The polyester copolymer according to one embodiment contains a polyvalent carboxylic acid residue (A) and a polyhydric alcohol residue (B). Further, the polyester copolymer may have a residue (C) derived from other components other than the polyvalent carboxylic acid residue (A) and the polyhydric alcohol residue (B). The polyester copolymer may be only one kind, or may be a combination of two or more kinds.

[0011] 1.1.1 Polyvalent carboxylic acid residue (A) In the polyester copolymer according to one embodiment, the polyvalent carboxylic acid residue (A) includes a terephthalic acid residue (A1) and a polyvalent carboxylic acid residue (A2) containing a metal sulfonate group. Further, the polyvalent carboxylic acid residue (A) may include other polyvalent carboxylic acid residues (A3) other than the residues (A1) and (A2).

[0012] 1.1.1.1 Terephthalic acid residue (A1) The terephthalic acid residue (A1) is derived from a terephthalic acid compound. Examples of the terephthalic acid compound include terephthalic acid and those obtained by alkyl-esterifying terephthalic acid. Examples of those obtained by alkyl-esterifying terephthalic acid include those obtained by alkyl (having 1 to 4 carbon atoms)-esterifying terephthalic acid such as dimethyl terephthalate. The terephthalic acid compound constituting the terephthalic acid residue (A1) may be only one kind, or a combination of two or more kinds.

[0013] In the polyester copolymer according to one embodiment, the average ratio of the terephthalic acid residue (A1) in the polyvalent carboxylic acid residue (A) is 73% by mass or more and 99% by mass or less. If the ratio of the terephthalic acid residue (A1) is too small or too large, it becomes difficult to achieve both adhesiveness and flexibility. From the viewpoint of adhesiveness to the base fabric, the average ratio of the terephthalic acid residue (A1) in the polyvalent carboxylic acid residue (A) is preferably 80% by mass or more and 95% by mass or less.

[0014] In the present application, "the average proportion of terephthalic acid residue (A1) in the polyvalent carboxylic acid residue (A) is 73% by mass or more and 99% by mass or less" means, for example, a polyester copolymer (X1) in which the proportion of terephthalic acid residue (A1) in the polyvalent carboxylic acid residue (A) is relatively small (for example, less than 73% by mass), and a polyester copolymer (X2) in which the proportion of terephthalic acid residue (A1) in the polyvalent carboxylic acid residue (A) is relatively large (for example, more than 99% by mass) are combined. As a result, as the entire polyester copolymer (X1 + X2), it also includes a concept in which the average proportion of terephthalic acid residue (A1) in the polyvalent carboxylic acid residue (A) is 73% by mass or more and 99% by mass or less. Hereinafter, the same applies to the "average proportion" of residues (A2) to (A3) and (B1) to (B2).

[0015] 1.1.1.2 Polyvalent carboxylic acid residue (A2) containing a metal sulfonate group The polyvalent carboxylic acid residue (A2) containing a metal sulfonate group is derived from a polyvalent carboxylic acid containing a metal sulfonate group. Examples of the polyvalent carboxylic acid containing a metal sulfonate group include sulfophthalic acid salts such as 2-sulfoisophthalate, 4-sulfoisophthalate, and 5-sulfoisophthalate; metal sulfonate group-containing aromatic dicarboxylic acid salts other than sulfophthalic acid salts such as 4-sulfo-2,6-naphthalenedicarboxylate; esterified products of metal sulfonate group-containing aromatic dicarboxylic acids; anhydrides of metal sulfonate group-containing aromatic dicarboxylic acids, and the like. Examples of the metal constituting the salt include lithium, sodium, potassium, magnesium, etc. From the viewpoint of emulsion stabilization of the polyester polymer, one or both of sodium and potassium are preferable. Among these, a preferable one is, for example, sodium 5-sulfoisophthalate from the viewpoint of emulsion stabilization of the polyester polymer. The polyvalent carboxylic acid containing a metal sulfonate group constituting the polyvalent carboxylic acid residue (A2) containing a metal sulfonate group may be only one kind, or a combination of two or more kinds.

[0016] In the polyester copolymer according to one embodiment, the average proportion of the metal sulfonate group-containing polyvalent carboxylic acid residue (A2) in the polyvalent carboxylic acid residue (A) may be more than 0% by mass. The upper limit is not particularly limited and can be determined according to the average proportion of the terephthalic acid residue (A1). The average proportion of the metal sulfonate group-containing polyvalent carboxylic acid residue (A2) in the polyvalent carboxylic acid residue (A) is preferably 5% by mass or more and 10% by mass or less.

[0017] 1.1.1.3 Other polyvalent carboxylic acid residues (A3) The other polyvalent carboxylic acid residues (A3) are derived from polyvalent carboxylic acids other than the terephthalic acid and the metal sulfonate group-containing polyvalent carboxylic acid. Examples of the other polyvalent carboxylic acids include aromatic dicarboxylic acids having 8 to 18 carbon atoms other than terephthalic acid such as phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,5-furandicarboxylic acid; those obtained by alkyl (for example, having 1 to 4 carbon atoms) esterifying the aromatic dicarboxylic acids having 8 to 18 carbon atoms other than the terephthalic acid; alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid; esterified products of the alicyclic dicarboxylic acids; anhydrides of the alicyclic dicarboxylic acids; aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, dodecanedioic acid; esterified products of the aliphatic dicarboxylic acids; anhydrides of the aliphatic dicarboxylic acids; aromatic tricarboxylic acids such as trimellitic acid, hemimellitic acid, trimesic acid, 1,2,5-naphthalenetricarboxylic acid; esterified products of the aromatic tricarboxylic acids; anhydrides of the aromatic tricarboxylic acids; alicyclic tricarboxylic acids such as 1,2,4-cyclohexanetricarboxylic acid; esterified products of the alicyclic tricarboxylic acids; anhydrides of the alicyclic tricarboxylic acids; aliphatic tricarboxylic acids such as 1,2,3-butanetricarboxylic acid; esterified products of the aliphatic tricarboxylic acids; anhydrides of the aliphatic tricarboxylic acids; polyvalent carboxylic acids having 3 or more valences such as pyromellitic acid; esterified products of the polyvalent carboxylic acids having 3 or more valences; anhydrides of the polyvalent carboxylic acids having 3 or more valences, and the like. The other polyvalent carboxylic acids may be only one kind or a combination of two or more kinds.

[0018] In the polyester copolymer according to one embodiment, the average proportion of other polyvalent carboxylic acid residues (A3) in the polyvalent carboxylic acid residue (A) may be 0% by mass or more. The upper limit is not particularly limited and can be determined according to the average proportions of the terephthalic acid residue (A1) and the polyvalent carboxylic acid residue (A2) containing a metal sulfonate group.

[0019] 1.1.2 Polyhydric alcohol residue (B) In the polyester copolymer according to one embodiment, the polyhydric alcohol residue (B) contains a polyethylene glycol residue (B1) having a number average molecular weight of 800 or more and 6000 or less. Further, the polyhydric alcohol residue (B) may contain other polyhydric alcohol acid residues (B2) other than the residue (B1).

[0020] 1.1.2.1 Polyethylene glycol residue (B1) The polyethylene glycol residue (B1) is derived from polyethylene glycol having a number average molecular weight of 800 or more and 6000 or less. The "number average molecular weight" is calculated from the hydroxyl value obtained by the acetic anhydride pyridine method. For example, for commercially available products, the value presented by the polyethylene glycol manufacturer can be used. From the viewpoint of viscosity retention of the coating agent, the number average molecular weight of polyethylene glycol is preferably 2000 or more and 4000 or less. There may be only one kind of polyethylene glycol, or a combination of two or more kinds.

[0021] In the polyester copolymer according to one embodiment, the average proportion of the polyethylene glycol residue (B1) having a number average molecular weight of 800 or more and 6000 or less in the polyhydric alcohol residue (B) may be more than 0% by mass and 100% by mass or less. The average proportion may be 40% by mass or more and 80% by mass or less, or 50% by mass or more and 70% by mass or less.

[0022] 1.1.2.2 Other polyhydric alcohol residues The other polyhydric alcohol residues (B2) are derived from polyhydric alcohols other than polyethylene glycol having the above-mentioned predetermined number average molecular weight. Examples of the other polyhydric alcohols include aliphatic or aromatic polyhydric alcohols such as ethylene glycol, alkylene glycols having 3 or more carbon atoms, neopentyl glycol, polyalkylene glycols, Pluronic (registered trademark) type surfactants, and ethylene oxide adducts of bisphenol A.

[0023] In the polyester copolymer according to one embodiment, the average proportion of the other polyhydric alcohol residues (B2) in the polyhydric alcohol residues (B) may be 0% by mass or more. The upper limit is not particularly limited and can be determined according to the average proportion of the above polyethylene glycol residues (B1).

[0024] 1.1.3 Intramolecular content of each residue In the polyester copolymer according to one embodiment, the intramolecular content of the terephthalic acid residue (A1) is preferably 30% by mass or more and 50% by mass or less, the intramolecular content of the metal sulfonate group-containing polycarboxylic acid residue (A2) is preferably 1% by mass or more and 5% by mass or less, and the intramolecular content of the polyethylene glycol residue (B1) having a number average molecular weight of 800 or more and 6000 or less is preferably 30% by mass or more and 50% by mass or less.

[0025] 1.1.4 Residues derived from other components The polyester copolymer according to one embodiment may optionally contain residues derived from a reaction catalyst, for example, to promote the polymerization reaction. Examples of the reaction catalyst include fatty acid metal salts such as zinc acetate, and titanium alkoxides such as tetra-n-propyl titanate and tetra-n-butyl titanate.

[0026] 1.1.5 Mixture of two or more polyester copolymers As described above, in the aqueous coating agent according to one embodiment, only one type of polyester copolymer may be used alone, or two or more types may be used in combination. Also, as described above, for example, a polyester copolymer (X1) having a terephthalic acid residue (A1) ratio of less than 73% by mass and a polyester copolymer (X2) having a ratio of more than 99% by mass may be combined so that the average ratio of the terephthalic acid residue (A1) in the entire polyester copolymer mixture is 73% by mass or more and 99% by mass or less. The aqueous coating agent according to one embodiment, as the polyester copolymer, (I) a form containing only at least one polyester copolymer having a terephthalic acid residue (A1) ratio of 73% by mass or more and 99% by mass or less (II) a form containing at least one polyester copolymer having a terephthalic acid residue (A1) ratio of 73% by mass or more and 99% by mass or less and at least one polyester copolymer having a terephthalic acid residue (A1) ratio of less than 73% by mass and / or more than 99% by mass (III) a form containing only a plurality of types of polyester copolymers having a terephthalic acid residue (A1) ratio of less than 73% by mass and / or more than 99% by mass may be any of them.

[0027] 1.1.6 Weight-average molecular weight of polyester copolymer The polyester copolymer according to one embodiment preferably has a weight-average molecular weight of 5000 or more and 50000 or less from the viewpoint of the viscosity of the aqueous coating agent. The weight-average molecular weight is more preferably 10000 or more and 30000 or less. Here, the "weight-average molecular weight" is measured using gel permeation chromatography [equipment: HLC-8120 (manufactured by Tosoh Corporation), column: GF310HQ (manufactured by Shodex), and 50% (v / v) acetonitrile water as the mobile phase, with sodium polystyrene sulfonate as the standard substance].

[0028] 1.1.7 Method for producing polyester copolymer The method for producing the above polyester copolymer is not particularly limited. For example, necessary components for constituting the polyester copolymer such as aromatic dicarboxylic acids containing terephthalic acid, aromatic dicarboxylic acid alkyl esters containing terephthalic acid alkyl esters, polyvalent carboxylic acids containing metal sulfonate groups, polyhydric alcohols, etc., and optionally reaction catalysts such as fatty acid metal salts are charged in predetermined amounts respectively, and while stirring under a nitrogen gas atmosphere, the temperature is raised to an arbitrary temperature of 100°C or higher and 300°C or lower over about 1 hour or more and 5 hours or less to carry out a transesterification reaction, and water and alcohol etc. produced by the reaction are distilled out of the system. Next, a reaction catalyst such as titanium alkoxide is optionally added and the pressure is gradually reduced, the internal pressure is set to 5 kPa or higher and 50 kPa or lower, and the reaction is carried out at 200°C or higher and 300°C or lower for 1 hour or more and 3 hours or less, whereby the above polyester copolymer can be obtained.

[0029] 1.2 Components other than the polyester copolymer The aqueous coating agent according to one embodiment contains at least the above polyester copolymer. The aqueous coating agent may contain other components together with the above polyester copolymer. Examples of other components include water and various additives.

[0030] 1.2.1 Water The aqueous coating agent may contain water together with the above polyester copolymer. In one embodiment, the mass ratio of the polyester copolymer to water (polyester copolymer / water) contained in the aqueous coating agent is preferably 5 / 95 to 40 / 60, more preferably 15 / 85 to 30 / 70, from the viewpoints of adhesiveness, flexibility, and viscosity stability.

[0031] The aqueous coating agent according to one embodiment can be produced, for example, by a method of mixing and emulsifying the above polyester copolymer and water at 80°C or higher and 90°C or lower; a method of mixing and emulsifying with an emulsifying disperser such as a homomixer or a high-pressure homogenizer; etc.

[0032] 1.2.2 Other additives The aqueous coating agent according to one embodiment may contain, if necessary, at least one selected from, for example, diluting components such as solvents, curing catalysts, surface modifiers, defoamers, flame retardants, film-forming aids, ultraviolet absorbers, antioxidants, pH adjusters, thickeners, and the like. The aqueous coating agent according to one embodiment can be prepared by mixing the respective components constituting the aqueous coating agent by ordinary means. However, when using the aqueous coating agent for a vehicle ceiling skin member enabling reusable monomerization described later, from the viewpoint of monomerization, it is preferable not to contain compounds other than polyesters such as acrylic or urethane thickeners, curing catalysts of hydrophilically modified carbodiimide compounds, and phosphorus-based flame retardants.

[0033] 1.3 Viscosity The aqueous coating agent according to one embodiment preferably has a viscosity of 5000 mPa·s or more and 50000 mPa·s or less, more preferably 10000 mPa·s or more and 30000 mPa·s or less at 20°C from the viewpoint of coating suitability such as uniform coatability.

[0034] 1.4 pH The aqueous coating agent according to one embodiment preferably has a pH of 3 or more and 7 or less, more preferably 4 or more and 6 or less from the viewpoint of viscosity stabilization of the aqueous coating agent.

[0035] 2. Method of using the aqueous coating agent The aqueous coating agent of the present disclosure can be applied to various substrates to form a coating layer on at least the surface of the substrates. The coating layer can also function as an adhesive layer for bonding the substrates together. As the substrate, for example, base fabrics such as polyester knitted fabrics and polyester non-woven fabrics described later can be adopted.

[0036] 2.1 Coating The coating method of the aqueous coating agent is not particularly limited, and a general method can be adopted. For example, it can be applied by brush coating; coating methods using various machines such as back coating and gravure coating. From the perspective of uniform coating, coating by back coating is preferred. The processing temperature during coating is not particularly limited, and for example, normal temperature may be used.

[0037] 2.2 Drying After applying the aqueous coating agent, drying treatment may be performed by a normal method using a dryer or the like. The drying treatment may be, for example, drying at a temperature of 80°C or higher and 130°C or lower for 30 seconds or longer and 30 minutes or shorter, or drying at a temperature of 150°C or higher and 200°C or lower for 10 seconds or longer and 10 minutes or shorter.

[0038] 2.3 Treatment amount of the aqueous coating agent The treatment amount of the aqueous coating agent on the substrate is not particularly limited, but from the perspective of adhesion to the substrate, in terms of the mass after drying (Dry coating amount) conversion, 5 g / m 2 or more and 40 g / m 2 or less is preferred, and 15 g / m 2 or more and 30 g / m 2 or less is more preferred.

[0039] 3. Ceiling skin member for vehicles By subjecting the base fabric to the above coating treatment using the aqueous coating agent of the present disclosure, for example, a ceiling skin member for a vehicle can be manufactured. The ceiling skin member for a vehicle according to one embodiment has a polyester knitted fabric and a polyester nonwoven fabric. Here, the polyester knitted fabric and the polyester nonwoven fabric are laminated via a polyester copolymer contained in the aqueous coating agent of the present disclosure. In other words, in the ceiling skin member for a vehicle according to one embodiment, the polyester knitted fabric and the polyester nonwoven fabric are laminated via a polyester copolymer, the polyester copolymer contains a polyvalent carboxylic acid residue and a polyhydric alcohol residue, the polyvalent carboxylic acid residue contains a terephthalic acid residue and a polyvalent carboxylic acid residue containing a metal sulfonate group, the polyhydric alcohol residue contains a polyethylene glycol residue having a number average molecular weight of 800 or more and 6000 or less, and the average ratio of the terephthalic acid residue in the polyvalent carboxylic acid residue contained in the polyester copolymer is 73% by mass or more and 99% by mass or less. The ceiling skin member for a vehicle according to one embodiment has a simple three-layer structure of a polyester knitted fabric, a component (polyester copolymer) derived from an aqueous coating agent, and a polyester nonwoven fabric. In this case, since each layer of the ceiling skin member for a vehicle is composed of a polyester compound, it can be recycled by monomerization.

[0040] 3.1 Polyester knitted fabric The material of the polyester knitted fabric is a polyester-based synthetic fiber, and examples thereof include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene terephthalate / isophthalate, polyethylene terephthalate / 5-sodium sulfoisophthalate, polyethylene terephthalate / polyoxybenzoyl, polybutylene terephthalate / isophthalate, and the like.

[0041] The constituent yarns of the polyester knitted fabric may be raw yarns or dyed yarns (yarns dyed after spinning or after weaving). Further, a small amount of a matting agent such as titanium oxide, carbon black, an organic pigment excellent in heat resistance, a microporous forming agent such as kaolinite, an antistatic agent, etc. may be added to the constituent yarns. The cross-sectional shape of the constituent yarn is not particularly limited, and any cross-sectional shape of fiber such as a round cross-section, a multi-lobed cross-section, a polygonal cross-section, a flat cross-section, a hollow cross-section, and other special irregular cross-sections can be applied. Further, the constituent yarn may be a monofilament or a multifilament. The yarn used as a highly stretchable yarn is preferably a multifilament. The fineness of the single yarns constituting the multifilament is not particularly limited, but from the viewpoint of yarn strength, it is preferably 0.1 dtex or more and 10 dtex or less, and more preferably 0.5 dtex or more and 6 dtex or less.

[0042] The polyester knitted fabric has an excellent texture and a moderate fit, and warp knitting produced by a single jersey knitting machine or a double raschel knitting machine that can be knitted from a thin fabric to a thick fabric is preferable. The areal density of the knitted fabric is not particularly limited, but from the viewpoint of imparting elasticity, it is preferably 50 g / m 2 or more and 400 g / m 2 or less, more preferably 150 g / m 2 or more and 300 g / m 2 or less.

[0043] 3.2 Polyester non-woven fabric The polyester non-woven fabric is usually formed into a sheet shape by bonding what is called a web in which fibers are randomly stacked with an adhesive, entangling the fibers with each other by pressure such as a water flow, or utilizing the property of melting and solidifying by the heat of the fibers themselves to bond them to each other. Among them, a spunlace polyester non-woven fabric produced by the spunlace method that does not use a binder that injects a jet water flow onto the web deposited therein and entangles the fibers with each other by the pressure to bond them into a sheet shape is preferable from the viewpoints of being made of a single material and having a soft touch like that of a cloth and rich drapeability.

[0044] The material of the polyester non-woven fabric is a polyester-based synthetic fiber, such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene terephthalate / isophthalate, polyethylene terephthalate / 5-sodium sulfoisophthalate, polyethylene terephthalate / polyoxybenzoyl, polybutylene terephthalate / isophthalate, and the like.

[0045] 3.3 Other Configurations The specific forms and preferred forms of the polyester copolymer are as described above. From the perspective of weight reduction, it is preferable that the vehicle ceiling skin member does not laminate a structure other than the above three layers of the polyester knitted fabric, polyester non-woven fabric, and coating layer. Also, from the perspective of making the vehicle ceiling skin member a single material, it is preferable that it does not contain compounds other than polyester. However, the vehicle ceiling skin member may have a layer other than the three layers as needed. For example, for the purpose of imparting elasticity, an elastic layer containing glass fiber and rigid urethane foam may be laminated.

[0046] 4. Manufacturing Method of Vehicle Ceiling Skin Member The technology of the present disclosure also has aspects as a manufacturing method of a ceiling skin member for a vehicle. That is, a manufacturing method of a ceiling skin member for a vehicle according to an embodiment includes applying the aqueous coating agent of the present disclosure to one or both of a polyester knitted fabric and a polyester nonwoven fabric, and after applying the aqueous coating agent, bonding the polyester knitted fabric and the polyester nonwoven fabric through the polyester copolymer contained in the aqueous coating agent. More specifically, for example, by applying and drying the aqueous coating agent of the present disclosure to one or both of a polyester knitted fabric and a polyester nonwoven fabric, a coating layer is formed on the surface of one or both of the polyester knitted fabric and the polyester nonwoven fabric, and the polyester knitted fabric and the polyester nonwoven fabric are crimped by sandwiching the coating layer between the polyester knitted fabric and the polyester nonwoven fabric. The coating method of the aqueous coating agent and the drying treatment after coating are as described above. When crimping, heating may be optionally performed.

Example

[0047] As described above, one embodiment of the technology of the present disclosure has been described. However, the technology of the present disclosure can be variously modified other than the above embodiments without departing from the gist thereof. Hereinafter, the technology of the present disclosure will be described in more detail while showing examples, but the technology of the present disclosure is not limited to the following examples.

[0048] 1. Raw materials used The raw materials used in this example are as follows. · Dimethyl terephthalate (manufactured by Tokyo Chemical Industry Co., Ltd.) · Dimethyl isophthalate (manufactured by Tokyo Chemical Industry Co., Ltd.) · Trimethyl trimellitate (manufactured by Tokyo Chemical Industry Co., Ltd.) · Dimethyl adipate (manufactured by Tokyo Chemical Industry Co., Ltd.) · Sodium dimethyl 5-sulfoisophthalate (manufactured by Tokyo Chemical Industry Co., Ltd.) · Polyethylene glycol (Mn: 600) (Product name: PEG-600, manufactured by Sanyo Chemical Industries, Ltd.) · Polyethylene glycol (Mn: 1000) (Product name: PEG-1000, manufactured by Sanyo Chemical Industries, Ltd.) · Polyethylene glycol (Mn: 3400) (Product name: PEG-4000S, manufactured by Sanyo Chemical Industries, Ltd.) · Polyethylene glycol (Mn: 8300) (Product name: PEG-6000P, manufactured by Sanyo Chemical Industries, Ltd.) · Ethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) · Neopentyl glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) · Zinc acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) · Tetrabutyl titanate (manufactured by Tokyo Chemical Industry Co., Ltd.) · Acrylic thickener (Product name: Neo Sticker V-420, manufactured by Nihon Kayaku Co., Ltd.)

[0049] 2. Preparation of aqueous coating agent 2.1 Example 1 Into a reaction vessel, 524.3 g of dimethyl terephthalate, 38.8 g of isophthalic acid, 35.5 g of sodium dimethyl 5-sulfoisophthalate, 400.2 g of polyethylene glycol with a number average molecular weight of 3400, 127.1 g of ethylene glycol, 104.0 g of neopentyl glycol and 0.1 g of zinc acetate were charged. While stirring under a nitrogen gas atmosphere, the temperature was raised from 150 °C to 230 °C over about 3 hours to conduct a transesterification reaction, and water and methanol were distilled out of the system. Next, 0.1 g of tetrabutyl titanate was added and the pressure was gradually reduced to an internal pressure of about 10 kPa, and the reaction was carried out at 250 °C for 2 hours to obtain a polyester copolymer.

[0050] The ratio of terephthalic acid residues to polyvalent carboxylic acids in the obtained polyester copolymer was 87% by mass, and the weight average molecular weight was 16,800.

[0051] After heating and dissolving 250 g of the obtained polyester copolymer at 80 to 90°C, 750 g of water was added, and after mixing, high-pressure homogenizer treatment was performed, followed by cooling to room temperature to obtain an aqueous coating agent having a viscosity of 17,800 mPa·s (20°C) and a pH of 4.2.

[0052] 2.2 Examples 2 to 14, Comparative Examples 1 to 6 As shown in Tables 1 and 2, polyester copolymers were obtained according to the same synthesis method as in Example 1, except that the types, blending amounts, and reaction times of the respective raw materials were changed. Also, for the aqueous coating agent, as shown in Tables 1 and 2, an aqueous coating agent was obtained according to the same method as in Example 1, except that a pH adjuster and a thickener were arbitrarily added.

[0053] 2.3 Example 15 125 g of the polyester copolymer of Comparative Example 1 and 125 g of the polyester copolymer of Comparative Example 2 were heated and dissolved at 80 to 90°C, 750 g of water was added, and after mixing, high-pressure homogenizer treatment was performed, followed by cooling to room temperature. The ratio of terephthalic acid residues to polyvalent carboxylic acid residues in the obtained polyester copolymer was 86% by mass, and an aqueous coating agent having a viscosity of 13,700 mPa·s (20°C) and a pH of 4.5 was obtained.

[0054] 3. Evaluation method 3.1 Physical property evaluation 3.1.1 Viscosity After adjusting the aqueous coating agent as described above, the viscosity after standing at 20°C for 1 hour and the viscosity after standing at 40°C for 10 days and then returning to 20°C were measured with a viscometer (equipment: Toki Sangyo Co., Ltd. / TVB-10M, BM-4 rotor).

[0055] 3.1.2 pH After adjusting the aqueous coating agent as described above, the pH after standing at room temperature for 1 hour and the pH after standing at 40°C for 10 days and then returning to room temperature were measured with a pH meter (equipment: Horiba, Ltd. / D52).

[0056] 3.2 Performance evaluation 3.2.1 Preparation of test pieces 100% polyester double jersey fabric (thickness 2 mm, basis weight 240 g / m 2 ) on the back surface, an aqueous coating agent was applied at 30 g / m 2 (dry weight) using a roll coater and dried at 130 °C for 3 minutes. Subsequently, a 100% polyester spunlace nonwoven fabric (basis weight 50 g / m 2 ) was overlaid and heat-pressed at 150 °C for 15 seconds to obtain a test piece for evaluation. The pressure during heat pressing was 0.2 kg / m 2 .

[0057] 3.2.2 Evaluation of peel strength The adhesive strength of the aqueous coating agent was evaluated based on the peel strength of the peel strength test. For the above test piece, the 180-degree peel strength after 24 hours was measured at 23 °C and 65% RH atmosphere using an autograph (Shimadzu Corporation / AG-IS). Also, the peel strength of the test piece after 24 hours under wet heat aging (50 °C, 65% RH, 400 hours) in the atmosphere of 23 °C and 65% RH was measured. The peel strength was considered qualified if it was 7 N or more after 24 hours and 6 N or more after wet heat aging.

[0058] 3.2.3 Evaluation of flexibility The flexibility of the above test piece was evaluated by touch in the following 5 grades. A score of 3 or more was considered qualified. 5: Soft 4: Slightly soft 3: Moderate 2: Slightly hard 1: Hard

[0059] 4. Evaluation results The evaluation results are shown in Tables 1 and 2 below.

Table 1

Table 2

[0060] From the results shown in Tables 1 and 2, it can be seen that an aqueous coating agent containing a polyester copolymer that satisfies the following requirements (1) to (3) can achieve both adhesion (peel strength) and flexibility. (1) The polyvalent carboxylic acid residues contained in the polyester copolymer include terephthalic acid residues and polyvalent carboxylic acid residues containing metal sulfonate groups. (2) The polyhydric alcohol residues contained in the polyester copolymer include polyethylene glycol residues having a number average molecular weight of 800 or more and 6000 or less. (3) The average proportion of terephthalic acid residues in the polyvalent carboxylic acid residues contained in the polyester copolymer is 73% by mass or more and 99% by mass or less.

Industrial Applicability

[0061] The aqueous coating agent of the present disclosure can achieve both adhesiveness and flexibility, and can be expected to be applied to various uses in the field of textile processing such as ceiling skin members for vehicles.

Claims

1. An aqueous coating agent containing a polyester copolymer, wherein the polyester copolymer contains a polyvalent carboxylic acid residue and a polyhydric alcohol residue, the polyvalent carboxylic acid residue contains a terephthalic acid residue and a polyvalent carboxylic acid residue containing a metal sulfonate group, the polyhydric alcohol residue contains a polyethylene glycol residue having a number average molecular weight of 800 or more and 6000 or less, the average ratio of the terephthalic acid residue in the polyvalent carboxylic acid residue contained in the polyester copolymer is 73% by mass or more and 99% by mass or less, an aqueous coating agent.

2. The aqueous coating agent according to Claim 1, wherein the polyester copolymer has a weight average molecular weight of 5000 or more and 50000 or less, an aqueous coating agent.

3. The aqueous coating agent according to Claim 1, having a viscosity of 5000 mPa·s or more and 50000 mPa·s or less at 20°C, an aqueous coating agent.

4. A ceiling skin member for a vehicle having a polyester knitted fabric and a polyester non-woven fabric, wherein the polyester knitted fabric and the polyester non-woven fabric are laminated via the polyester copolymer contained in the aqueous coating agent according to any one of Claims 1 to 3, a ceiling skin member for a vehicle.

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