JP7141218B2 - Aqueous surface treatment agent and skin material - Google Patents

Description

TECHNICAL FIELD The present invention relates to an aqueous surface treatment agent and skin material, and more particularly to a polyurethane-based aqueous surface treatment agent and skin material that can impart abrasion resistance, cold flex resistance and heat shrinkage resistance.

Automotive interior parts such as instrument panels, door trims, seats, ceilings, railway vehicle and aircraft interior parts, furniture, shoes, footwear, bags, interior and exterior materials for construction, clothing upholstery and lining, wall coverings, etc. Synthetic resin skin materials with excellent durability are often used.

Such a synthetic resin skin material has unevenness similar to natural leather on the outermost surface, that is, a grain pattern, and a matte tone that suppresses gloss and luster and creates a calm texture. The appearance is characterized by matte tone. For example, with regard to automotive interior products, it has become important to impart a sense of quality to interior skin materials as vehicles become more sophisticated.

A conventional synthetic resin skin material having a vinyl chloride resin layer that has undergone surface treatment has a soft touch. For example, if a thin vinyl chloride resin sheet with excellent flexibility is used near the surface, However, there is a problem that the wear resistance of the steel is lowered. Automobile interior parts and furniture that are used on a daily basis require durability, so it is important to maintain good appearance and texture for a long period of time.

In order to improve wear resistance, it is conceivable to thicken the vinyl chloride resin layer existing near the surface or to use a high-strength vinyl chloride resin layer. However, when such a vinyl chloride resin layer is employed, not only does the texture deteriorate, but flexibility and bendability also decrease, making it difficult to apply it as a surface material for vehicle seats and the like. That is, there is a demand for a synthetic resin skin material that is more flexible and has excellent durability.
In addition, from the standpoint of environmental problems and safety, there is a shift to water-based surface treatment agents that minimize the use of organic solvents.

In Patent Document 1, by using an aqueous surface treatment agent containing an aqueous polyurethane with a specific modulus and a carbodiimide-based cross-linking agent, an organic solvent is not substantially contained, and excellent durability is obtained without impairing the flexibility of the applied surface material. A surface treatment agent that imparts wearability has been proposed.

Republished patent WO2015/107933

By the way, automotive interior parts and the like are required to have flexibility in cold climates (flexibility in cold weather) as well as further improvement in wear resistance. It is unknown whether the surface treatment agent of Patent Literature 1 can satisfy the above cold flex resistance.
In addition, there is also a problem that wrinkles are generated due to heat shrinkage in the step of heating and foaming after applying the surface treatment agent to the vinyl chloride skin material.

In view of the above, the present invention provides a water-based surface treatment agent capable of imparting wear resistance, cold flex resistance and heat shrinkage resistance when used as a skin material, and a skin material having a film comprising the surface treatment agent. aim.

As a result of intensive studies, the present inventors have found that an aqueous surface treatment agent using a polyurethane resin having a 100% modulus and a thermal softening point within predetermined ranges can solve the above problems, and completed the present invention. That is, the present invention is as follows.

[1] An aqueous surface treatment agent containing a polyurethane resin having a 100% modulus of 6 to 17 MPa and a thermal softening point of 30 to 55°C.
[2] The water-based surface treatment agent according to [1], wherein the polyurethane resin is modified with siloxane.
[3] The water-based surface treatment agent according to [1] or [2], which contains a matting agent.
[4] The aqueous surface treatment agent according to any one of [1] to [3], containing at least one selected from the group consisting of acrylic resins and polyvinyl chloride resins.
[5] The aqueous surface treatment agent according to any one of [1] to [4], which contains an oxazoline-based cross-linking agent.
[6] A skin material comprising a base material and a film comprising the surface treatment agent according to any one of [1] to [5].

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an aqueous surface treatment agent capable of imparting wear resistance, cold bending resistance and heat shrinkage resistance when used as a skin material, and a skin material having a film comprising the surface treatment agent. .

[Aqueous surface treatment agent]
The water-based surface treatment agent of the present invention contains a polyurethane resin having a 100% modulus of 6 to 17 MPa and a thermal softening point of 30 to 55°C.
In the present invention, the 100% modulus of the polyurethane resin is set to 6 to 17 MPa to improve the wear resistance. , cold bending resistance and heat shrinkage resistance are also good.

If the 100% modulus is less than 6, the abrasion resistance is lowered, and if it exceeds 17 MPa, the cold bending resistance and heat shrinkage resistance are lowered. The 100% modulus is preferably 6-16 MPa, more preferably 7-16 MPa.

Further, when the heat softening point of the polyurethane resin is less than 30°C, the wear resistance is lowered, and when it exceeds 55°C, the cold bending resistance and heat shrinkage resistance are lowered. The heat softening point is preferably 30 to 50°C, more preferably 35 to 49°C.
In addition, "aqueous" in the water-based surface treatment agent of the present invention means that the main component (for example, 70% by mass or more) of the solvent is water.

The water-based surface treatment agent of the present invention appropriately contains at least one selected from the group consisting of matting agents, acrylic resins and polyvinyl chloride resins, an oxazoline-based cross-linking agent, and the like, in addition to the above polyurethane resin.
Hereinafter, each component blended in the present invention will be described in more detail.

<Polyurethane resin>
The polyurethane resin used in the surface treatment agent of the present invention is mainly obtained from a high-molecular polyol and polyisocyanate, and if necessary, a chain extension agent such as a short-chain diol or a short-chain diamine, or a chain extension terminator is used. A compound or the like having one or more active hydrogen groups and a hydrophilic group may also be used. Furthermore, a polysiloxane compound may be used when modifying a polyurethane resin with polysiloxane.

(Polymer polyol)
Examples of polymer polyols include the following (1) to (6).
(1) Polycarbonate Polyol Polycarbonate polyols include polycarbonate diols such as polytetramethylene carbonate diol, polypentamethylene carbonate diol, polyneopentyl carbonate diol, polyhexamethylene carbonate diol, and poly(1,4-cyclohexanedimethylene carbonate) diol. , and random/block copolymers thereof.

(2) Polyether polyol Polyether polyols include those obtained by polymerizing or copolymerizing any of alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) and heterocyclic ethers (tetrahydrofuran, etc.). . Specific examples include polyethylene glycol, polypropylene glycol, polyethylene glycol-polytetramethylene glycol (block or random), polytetramethylene ether glycol and polyhexamethylene glycol.

(3) Polyester polyol Polyester polyols include aliphatic dicarboxylic acids (e.g., succinic acid, adipic acid, sebacic acid, glutaric acid and azelaic acid), and aromatic dicarboxylic acids (e.g., isophthalic acid and terephthalic acid). ) and low molecular weight glycols (e.g., ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butylene glycol, 1,6-hexamethylene glycol, neopentyl glycol and 1,4-bishydroxymethylcyclohexane).
Specifically polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyneopentyl adipate diol, polyethylene/butylene adipate diol, polyneopentyl/hexyl adipate diol, poly-3-methylpentane adipate diol and polybutylene and isophthalate diol.

(4) Polylactone polyol Examples of polylactone polyol include polycaprolactone diol and poly-3-methylvalerolactone diol.
(5) Polyolefin Polyol Examples of polyolefin polyol include polybutadiene glycol, polyisoprene glycol, and hydrogenated products thereof.
(6) Polymethacrylate Diol Polymethacrylate diols include α,ω-polymethyl methacrylate diol and α,ω-polybutyl methacrylate diol.

The structure and molecular weight of these polymer polyols are not particularly limited, but the number average molecular weight is preferably about 500 to 4,000, and these polyols can be used alone or in combination of two or more. From the viewpoint of, it is preferable to contain a polycarbonate diol.
The number average molecular weight is a polystyrene-equivalent number average molecular weight, and can be usually determined by gel permeation chromatography (GPC).

(Polysiloxane compound)
A polysiloxane compound is used when modifying a polyurethane resin with polysiloxane. Abrasion resistance can be improved by modifying with polysiloxane. As the polysiloxane compound, compounds having the following structures (1) to (4) can be used.

(1) Amino-modified polysiloxane

(2) Epoxy-Modified Polysiloxane The following epoxy compounds can be used by reacting them with polyols, polyamides, polycarboxylic acids, etc. so as to have terminal active hydrogens.

(3) Alcohol-modified polysiloxane

(4) Mercapto-modified polysiloxane

The polysiloxane compounds (1) to (4) above are examples of preferred compounds, and the present invention is not limited to these exemplified compounds. Among the above, alcohol-modified polysiloxane is preferred, and the following compounds are more preferred.

(polyisocyanate)
Polyisocyanates include toluene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-isopropyl-1,3-phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4-butoxy- 1,3-phenylene diisocyanate, 2,4-diisocyanate diphenyl ether, 4,4′-methylenebis(phenylene isocyanate) (MDI), dulylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate (XDI), 1,5-naphthalene diisocyanate, aromatic diisocyanates such as benzidine diisocyanate, o-nitrobenzidine diisocyanate and 4,4′-diisocyanatodibenzyl; methylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate and 1,10-decamethylene diisocyanate; cycloaliphatic diisocyanates such as 1,4-cyclohexylene diisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate), 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, hydrogenated MDI and hydrogenated XDI, etc. Alternatively, polyurethane prepolymers obtained by reacting these diisocyanate compounds with low-molecular-weight polyols or polyamines so as to form isocyanate terminals may be used.

(Compound having one or more active hydrogens and a hydrophilic group)
As the compound having one or more active hydrogens and a hydrophilic group, known compounds used as components for imparting water dispersibility to polyurethane resin aqueous dispersions can be used.
In the compound, the active hydrogen is a hydrogen atom that reacts with the isocyanate group of the polyisocyanate, and includes hydrogen atoms such as a hydroxyl group, a mercapto group, and an amino group. Among these, the hydrogen atom of the hydroxyl group is preferred. The hydrophilic group is a functional group for imparting water dispersibility, and may be either anionic or cationic, but preferably anionic. The anionic hydrophilic group includes a carboxyl group, a sulfo group, a phosphoric acid group, etc. Among these, a carboxyl group is preferred.

As the compound whose hydrophilic group is anionic, those having a hydrophilic group such as sulfonic acid, carboxylic acid, and phosphoric acid can be used. For example, dimethylolpropanoic acid, dimethylolbutanoic acid, lactic acid, Carboxylic acid compounds such as glycine, and sulfonic acid compounds such as taurine and sulfoisophthalic acid-based polyester diols can be used.
Among these, it is preferable to use carboxylic acid compounds of dihydric alcohols, particularly dimethylolalkanoic acids such as dimethylolpropionic acid and dimethylolbutanoic acid.

A hydrophilic group may be neutralized with a neutralizing agent to form a salt. Neutralizing agents for anionic hydrophilic groups include aqueous ammonia, organic amines such as alkylamines such as ethylamine, trimethylamine, triethylamine, triisopropylamine and tributylamine, triethanolamine, N-methyldiethanolamine and N-phenyldiethanolamine. , monoethanolamine, diethanolamine, dimethylethanolamine, diethylethanolamine, 2-amino-2-ethyl-1-propanol; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide; etc. can be mentioned. Among these, tertiary alkylamines such as triethylamine and tertiary alkanolamines such as sodium hydroxide and dimethylaminoethanol are preferred.
In addition, the alkanolamine exemplified above can also be used as a chain extension terminator.

(Short chain diol)
The short-chain diol is a compound having a number average molecular weight of less than 500, and includes ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, 1,4-butylene glycol, Aliphatic glycols such as 6-hexamethylene glycol and neopentyl glycol and their alkylene oxide low molar adducts (number average molecular weight less than 500), 1,4-bishydroxymethylcyclohexane and 2-methyl-1,1-cyclohexane di Alicyclic glycols such as methanol and their alkylene oxide low molar adducts (number average molecular weight less than 500), aromatic glycols such as xylylene glycol and their alkylene oxide low molar adducts (number average molecular weight less than 500), Compounds such as bisphenols such as bisphenol A, thiobisphenols and sulfonebisphenols and their alkylene oxide low molar adducts (number average molecular weight less than 500), and alkyldialkanolamines such as C1-C18 alkyldiethanolamines.

(Short-chain diamine)
Short chain diamines include aliphatic diamine compounds such as ethylenediamine, trimethylenediamine, hexamethylenediamine and octamethylenediamine, phenylenediamine, 3,3′-dichloro-4,4′-diaminodiphenylmethane, 4,4′-methylenebis (phenylamine), aromatic diamine compounds such as 4,4′-diaminodiphenyl ether and 4,4′-diaminodiphenyl sulfone, cyclopentanediamine, cyclohexyldiamine, 4,4-diaminodicyclohexylmethane, 1,4-diaminocyclohexane and Alicyclic diamine compounds such as isophorone diamine, hydrazines such as hydrazine, carbodihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, phthalic acid dihydrazide, and the like.

The above are examples of preferred components, and the present invention is not limited to these. Therefore, not only the above-mentioned exemplary components, but also other compounds currently on the market and easily available from the market can all be used.

(Method for producing polyurethane resin)
The method for producing the polyurethane resin according to the present invention is not particularly limited, and conventionally known methods for producing polyurethane can be used. That is, a polymer polyol, a short-chain diol added as necessary, a polyisocyanate, and a compound having one or more active hydrogen groups and having a hydrophilic group are reacted, followed by a neutralizing agent, It can be produced by reacting a chain elongation agent such as a short-chain diamine or a chain elongation terminator.

Here, for example, by adjusting the ratio of the aliphatic diisocyanate and the alicyclic diisocyanate, the 100% modulus can be made within the desired range. Specifically, the 100% modulus can be increased by increasing the ratio of the alicyclic diisocyanate. Therefore, from the viewpoint of making the 100% modulus the desired range, the mass ratio of the aliphatic diisocyanate and the alicyclic diisocyanate (aliphatic diisocyanate/alicyclic diisocyanate) is preferably 5/95 to 40/60. , 7/93 to 35/65.

Further, for example, by adjusting the ratio of the aliphatic diamine compound and the alkanolamine, the thermal softening point can be set within the desired range. Specifically, the thermal softening point can be lowered by increasing the proportion of alkanolamine. Therefore, from the viewpoint of keeping the thermal softening point within the desired range, the mass ratio of the aliphatic diamine compound to the alkanolamine (aliphatic diamine compound/alkanolamine) is preferably 99/1 to 60/40. /3 to 63/37 is more preferable.

Moreover, in the above urethane synthesis, a catalyst can be used as necessary. For example, salts of metals and organic and inorganic acids such as dibutyltin laurate, dioctyltin laurate, stannus octoate, lead octoate, tetra-n-butyl titanate, and organometallic derivatives, organic amines such as triethylamine, diaza bicycloundecene-based catalysts, and the like.

The polyurethane resin may be synthesized without solvent, or may be synthesized using an organic solvent if necessary. Preferred organic solvents include those that are inert to isocyanate groups or less active than the reactive components. For example, ketone solvents (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), aromatic hydrocarbon solvents (toluene, xylene, Swasol (aromatic hydrocarbon solvents manufactured by Cosmo Oil Co., Ltd.), Solvesso (Exxon Chemical Co., Ltd.) Company-manufactured aromatic hydrocarbon solvents), aliphatic hydrocarbon solvents (n-hexane, etc.), alcohol solvents (methyl alcohol, ethyl alcohol, isopropyl alcohol, etc.), ether solvents (dioxane, tetrahydrofuran, etc.) , ester solvents (ethyl acetate, butyl acetate, isobutyl acetate, etc.), glycol ether ester solvents (ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, ethyl-3-ethoxypropyl acetate, pionate, etc.), amide solvents (dimethylformamide, dimethylacetamide, etc.), lactam solvents (N-methyl-2-pyrrolidone, etc.). Among these, methyl ethyl ketone, ethyl acetate, acetone, and tetrahydrofuran are preferred in consideration of solvent recovery, solubility during urethane synthesis, reactivity, boiling point, and emulsifying dispersibility in water.

Additives may be added as necessary in the production of the polyurethane resin. For example, antioxidants (hindered phenol, phosphite, thioether, etc.), light stabilizers (hindered amines, etc.), ultraviolet absorbers (benzophenone, benzotriazole, etc.), gas discoloration stabilizers (hydrazine, etc.) ), metal deactivators, and two or more of these.

<Matting agent>
In the case of making the film to be the surface material matte, it is preferable to incorporate a matting agent into the water-based surface treatment agent. Examples of matting agents include resin particles, silica particles, talc, aluminum hydroxide, calcium sulfate, calcium silicate, calcium carbonate, magnesium carbonate, barium carbonate, alumina silicate, molecular sieves, kaolin, mica, and mica.

(resin particles)
The resin particles are preferably crosslinked resins, and include polyurethane resins, acrylic resins, urea resins, silicone resin fine particles, fluororesin fine particles, silicone-modified urethane resin fine particles, polyethylene fine particles, polypropylene fine particles, reactive siloxane, and the like. Among these, polyurethane resins are preferred because they provide a good feel to the touch.
As the polyurethane resin, a polyurethane resin obtained by reacting a polyol and a polyisocyanate with a low-molecular-weight compound having two or more active hydrogens such as a diol, a diamine, or a dicarboxylic acid is chain-extended. A polyurethane resin obtained by reacting a polyol having an acidic group with a polyisocyanate may be mentioned.
As resin particles made of polyurethane resin, for example, Dymic Beads (manufactured by Dainichiseika Kogyo Co., Ltd.) and Art Pearl (manufactured by Negami Kogyo Co., Ltd.) can be used.

The volume average particle diameter of the resin particles is preferably 1 to 20 μm, more preferably 5 to 20 μm.
The volume average particle size in the present specification can be obtained from the 50% cumulative average value measured using Microtrac UPA (Nikkiso).

(silica particles)
Silica particles are not particularly limited to either natural products or synthetic products, but synthetic products include precipitation silica, gel silica, and dry silica. Among them, precipitation silica and dry silica are preferred.

The volume average particle size of silica particles is preferably 1 to 20 μm, more preferably 3 to 15 μm.

The matting agent may be resin particles alone, silica particles alone, or a mixture of resin particles and silica particles, but a mixture of resin particles and silica particles is preferred. The amount of the matting agent added is preferably 5 to 200 parts by mass, more preferably 30 to 150 parts by mass, per 100 parts by mass of the polyurethane resin.

<Additional resin>
Other resins (additional resins) can be added to the surface treatment agent of the present invention, if necessary.
The resin is preferably an aqueous dispersion, and an acrylic resin or a polyvinyl chloride resin is preferable because it can improve abrasion resistance.
Acrylic resins include polymethyl (meth)acrylate, polyethyl (meth)acrylate, polypropyl (meth)acrylate, polybutyl (meth)acrylate, methyl (meth)acrylate-butyl (meth)acrylate. (Meth) acrylics such as copolymers, ethyl (meth) acrylate-butyl (meth) acrylate copolymers, ethylene-methyl (meth) acrylate copolymers, styrene-methyl (meth) acrylate copolymers A (meth)acrylic resin made of a homopolymer or a copolymer containing an acid ester is exemplified. In addition, "(meth)acryl" means methacryl or acryl.
Examples of commercially available acrylic resins include Movinyl 6530 (manufactured by Japan Coating Resin Co., Ltd.), Vinyblan 2684 (manufactured by Nissin Chemical Industry Co., Ltd.), Saibinol EK-61 (manufactured by Saiden Chemical Co., Ltd.), and the like. The acrylic resin to be used preferably has a glass transition point (Tg) of 10 to 40°C, more preferably 20 to 35°C. Tg can be measured, for example, by thermal analysis using a differential scanning calorimeter (manufactured by Rigaku Corporation).

Polyvinyl chloride resins include homopolymers of vinyl chloride, copolymers of vinyl chloride and other copolymerizable monomers having a structural unit derived from vinyl chloride in a proportion of 70% by mass or more, and chlorinated products thereof. One or two or more of are preferably used. When polyvinyl chloride is a copolymer, vinyl chloride and one or more copolymerizable monomers such as ethylene, propylene, vinyl acetate, vinyl bromide, vinylidene chloride, acrylonitrile, and maleimide Copolymers are preferably used.
Examples of commercially available polyvinyl chloride resins include Vinyblan 278 manufactured by Nissin Chemical Industry Co., Ltd. and Vycar 460X119 (manufactured by Lubrizol). The polyvinyl chloride resin used preferably has a Tg of 10 to 40°C, more preferably 20 to 35°C.

The amount of the additive resin to be added is preferably 1 to 120 parts by mass, more preferably 5 to 80 parts by mass, per 100 parts by mass of the polyurethane resin. When the amount is 10 to 50 parts by mass, heat shrinkability and cold bending resistance can be maintained, and abrasion resistance can be further improved.

<Crosslinking agent>
By blending a cross-linking agent with the surface treatment agent of the present invention, a coating with further improved durability can be obtained.
As the cross-linking agent, cross-linking agents such as oxazoline compounds, carbodiimide compounds, isocyanate compounds and epoxy compounds can be used. Among these cross-linking agents, oxazoline compounds are preferable from the viewpoint of cold bending resistance and heat shrinkage resistance. The oxazoline group content (mmol/g, solid) of the oxazoline compound is preferably 1-8.
Examples of commercially available oxazoline compounds that can be used as a cross-linking agent include "Epocross" (manufactured by Nippon Shokubai Co., Ltd.).

If the amount of the cross-linking agent used is too large, problems such as embrittlement of the film and plasticization due to unreacted cross-linking agent may occur. Therefore, the amount of the cross-linking agent used is preferably 10 parts by mass or less, more preferably 1.0 to 7.5 parts by mass in terms of the solid content of the cross-linking agent, per 100 parts by mass of the polyurethane resin. .

<Solvent>
In the present invention, a solvent may be mixed for the purpose of adjusting the viscosity. As the solvent, water is preferable from an environmental point of view. It is preferable that water in the solvent is 70% by mass or more.

<Other additives>
The water-based surface treatment agent of the present invention may include slip agents, pigments, silane coupling agents, colorants, anti-mold agents, flame retardants, leveling agents, thickeners, and antifoaming agents, as long as they do not affect the effects of the present invention. agents, antioxidants, light stabilizers, UV absorbers, various surfactants, wetting agents, dispersants, film-forming aids, plasticizers, preservatives, antifungal agents, anti-algae agents, bactericides, antistatic agents Agents and the like can be added.

The gloss of the film made of the surface treatment agent of the present invention is preferably 0.3 to 4.0, more preferably 0.5 to 2.0, at 60° incident light/60° reflected light. When the gloss is 1 to 2, it is possible to achieve a matte tone that suppresses gloss and luster and creates a calm texture.
The gloss of the coating can be determined by the method described in the Examples.

[Skin material]
The skin material of the present invention has a base material coated with the surface treating agent of the present invention. As used herein, the term "film" refers to a film obtained by drying an undried "coating film" obtained by applying an aqueous surface treatment agent.

<Base material>
Examples of the base material for the skin material of the present invention include films and synthetic leathers using the following resins. Moreover, the base material may be a foam base material.
Examples of resins include polyvinyl chloride resins, polyethylene resins, polypropylene resins, olefin resins such as thermoplastic polyolefin, ethylene propylene diene resins, styrene acrylonitrile resins, polysulfone resins, polyphenylene ether resins, acrylic resins, Silicone resins, fluorine resins, polyester resins, polyamide resins, polyimide resins, polystyrene resins, polyurethane resins, polycarbonate resins, norbornene resins, cellulose resins, polyvinyl alcohol resins, polyvinyl formal resins, polyvinyl butyral-based resins, polyvinylpyrrolidone-based resins, polyvinyl acetal-based resins, polyvinyl acetate-based resins, engineering plastics, biodegradable plastics, and the like.
Especially for automobile interior materials, polyvinyl chloride resins, thermoplastic polyolefins, polyurethanes, polypropylenes, and the like can be mentioned.
Also, when the base material is a foam base material, a base material such as vinyl chloride resin can be used.
The thickness of the base material is preferably 0.2 to 0.8 mm, and when the base material is a foamed base material and is foamed, the thickness after foaming is 0.3 to 4.5 mm. is preferred.

<Method for manufacturing skin material>
The skin material of the present invention is produced by applying the aqueous surface treating agent of the present invention to a substrate, drying at 80 to 140° C., and crosslinking if necessary to form a coating.
When the substrate is a foamed substrate, for example, in the case of a polyvinyl chloride resin substrate sheet, a step of foaming the foaming agent in the vinyl chloride foamed layer composition by heating to form a vinyl chloride foamed layer (foaming step). is included. For example, prior to this step, the aqueous surface treating agent of the present invention is applied onto the substrate sheet by spray coating, gravure coating, or the like to form a coating film. Then, after drying at 80 to 140°C for 1 to 3 minutes to form a film, foaming treatment is performed at 130 to 230°C. Furthermore, in order to impart a design property, an embossing roll having a pattern engraved on the surface treatment layer side is pressed while the surface is heated (100 to 190 ° C.), thereby forming a pattern on the surface. A synthetic resin skin material (for example, a seat seat for an automobile) is formed (pattern pattern forming step).
When applying the water-based surface treatment agent of the present invention to a thermoplastic resin substrate having poor adhesiveness, it may be subjected to a primer treatment in order to improve adhesion to the paint.
Moreover, each of the foaming step and the pattern forming step may be performed prior to the step of forming the coating film, or may be performed after the surface treatment layer forming step. That is, there is a method of applying a surface treatment agent to a substrate before foaming and then heating and foaming, and a method of applying a surface treatment agent to a substrate after foaming. For the reason of improvement, the method of foaming after applying the surface treatment agent is preferred.
The film thickness of the film formed as described above is preferably 2 to 30 μm.

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples below, but the present invention is not limited thereto. In addition, "parts" below indicate parts by mass, and "%" indicates mass%.

PUDs 1 to 8, which are aqueous dispersions of polyurethane resins and siloxane-modified polyurethane resins used in this example, were prepared as follows.

First, after purging a reaction vessel equipped with a stirrer, a reflux condenser, a thermometer, a nitrogen blowing tube and a manhole with nitrogen gas, polycarbonate diol (Plaxel CD220, manufactured by Daicel Chemical Industries, Ltd., number average molecular weight 2,000), Predetermined amounts of 1,3-butanediol, polysiloxane diol (compound a) at both ends, dimethylolpropanoic acid and acetone shown in Table 1 below were added and uniformly dissolved to a solution concentration of 80%.
Subsequently, hexamethylene diisocyanate and methylene bis(4-cyclohexyl isocyanate) are added at a predetermined equivalent ratio (NCO/OH=1.4) and reacted at 80° C. until the NCO% reaches 1.5. Then, the solution concentration is diluted to 60%, cooled to 50 ° C., ion-exchanged water that becomes 20% with respect to the solid content, and a predetermined amount of neutralizing agent (triethylamine) (an amount equivalent to the hydrophilic group -COOH) In addition, the inside of the system was uniformly emulsified, and ethylenediamine and diethanolamine (an amount equivalent to the remaining NCO %) were added to extend and terminate the chain. Finally, the acetone in the system was vacuum degassed to obtain aqueous dispersions PUD1 to 8 of polyurethane resins and siloxane-modified polyurethane resins.

Abbreviations in Table 1 are as follows.
(1) PC diol: polycarbonate diol (2) 1,3BD: 1,3-butanediol (3) Si diol: the following compound a (n is an integer, number average molecular weight 1,900)

(4) HDI: hexamethylene diisocyanate (5) hydrogenated MDI: methylene bis(4-cyclohexyl isocyanate)
(6) EDA: ethylenediamine

Regarding PUD1 to 8, which are aqueous dispersions of polyurethane resins and siloxane-modified polyurethane resins, and PUD9, which is commercially available polyurethane resin aqueous dispersions (Superflex 500M: manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content 45%), polyurethane resin 100% modulus and thermal softening point were measured as follows.

<100% modulus>
First, a release paper was coated with an aqueous polyurethane dispersion and dried at 130° C. for 2 minutes to form a film, and a test piece having a thickness of 50 μm, a length of 60 mm, and a width of 10 mm was prepared. Both ends of this test piece were clamped with chucks, and pulled at a crosshead speed of 300 mm / min at 23 ° C. and a humidity of 50% using a tensile tester Autograph AGS-J (manufactured by Shimadzu Corporation). The 100% modulus of the specimen was measured. At this time, the distance between gauge lines was 20 mm, and the distance between chucks was 20 mm. The results are shown in Table 2 below.

<Thermal softening point>
The heat softening point was determined according to JIS-K7196-1991, specifically as follows.
A test piece prepared in the 100% modulus test was cut into 5 mm squares, and the thermal softening point was measured using a thermomechanical analyzer TMA SS7100 (manufactured by SII Nano Technology Inc.). In an environment of 23° C. and 50% humidity, the temperature was raised from 20 to 170° C. at a rate of 5° C./min. The results are shown in Table 2 below.

(Examples 1 to 6, Comparative Examples 1 to 3)
Each of PUD1 to PUD9, a matting agent, and a cross-linking agent were blended in ion-exchanged water at the ratios shown in Table 3 below to prepare water-based surface treatment agents of Examples 1 to 6 and Comparative Examples 1 to 3 each having a solid content of 20%. got Using these water-based surface treatment agents, gloss, heat shrinkage resistance, plane abrasion, and cold bending resistance tests were performed as follows. The results are shown in Table 3 below.

The details of the matting agent and the cross-linking agent are as follows.
(7) Matting agent/polyurethane resin particles: Artpearl C-400 transparent (manufactured by Negami Kogyo Co., Ltd., volume average particle diameter 15 μm, Tg=−13° C.)
・ Silica particles: ACEMATT TS-100 (manufactured by Evonik, volume average particle size 9.5 μm)

(9) Cross-linking agent Epocross WS-500 (manufactured by Nippon Shokubai Co., Ltd., oxazoline-based cross-linking agent, Tg = 16°C, oxazoline group equivalent = 220)

[Preparation of test sheet (1)]
The water-based surface treatment agent obtained in each example and comparative example was applied to a Leneta chart sheet (manufactured by Leneta Company) using a bar coater and dried in a dryer at 120°C for 1 minute to obtain a film thickness of 10 µm. A test sheet (1) was produced.

<gross>
Using a direct-reading haze computer HGM-2DP (manufactured by Suga Test Instruments Co., Ltd.), the gloss (60° incident light/60° reflected light) of the coating surface of test sheet (1) was measured. The results are shown in Table 3 below.

[Preparation of test sheet (2)]
The surface treatment agent obtained in each example and comparative example was applied to a PVC sheet using a bar coater and dried in a drier at 120° C. for 1 minute to prepare a test sheet (2) having a film thickness of 10 μm.

<Heat shrinkage resistance>
The surface treatment agent obtained in each example and comparative example was applied to a PVC substrate using a bar coater, dried for 1 minute in a drier at 120°C, and then dried in a drier at 220°C for 1 minute. I checked the appearance of The evaluation indices were as follows.
A: 0 or more and less than 3 wrinkles in a test piece of 100 mm × 100 mm due to visual heat shrinkage B: 3 or more and less than 10 wrinkles in a test piece of 100 mm × 100 mm due to visual heat shrinkage C: Visual heat shrinkage 10 or more wrinkles in a 100mm x 100mm test piece

<Plane wear>
Measured using a JASO M 403/88/flat abrasion tester for fabric materials for seat coverings (B method, Daiei Kagaku Seiki Seisakusho Co., Ltd.). The measurement method is to take a test sheet (2) with a width of 70 mm and a length of 300 mm one by one from the vertical and horizontal directions, place a cushion material on the flat abrasion table of the tester, and then place the test sheet (2) on it. It was placed face up and fixed with a clamp. Next, it was placed on the test sheet (2) to which No. 6 cotton canvas of JIS L 3102 (cotton canvas) was attached. The pressing load including the friction element was 9.81 N (1 kgf), the stroke was 140 mm, and the speed was 60±10 reciprocations/min. 10000 reciprocating tests were conducted as The evaluation indices were as follows.
A: No change in appearance B: 1 or more but less than 10 visible scratches C: 10 or more visible scratches

<Cold resistance bending test>
Using a Dematcher tester, a test sheet (2) having a width of 50 mm and a length of 150 mm was subjected to a bending test at a low temperature (-10°C) with a bending stroke of 100 mm. The evaluation indices were as follows.
A: No whitening or cracking at 10,000 cycles B: Whitening or cracking at 5,000 or more and less than 10,000 cycles C: Whitening or cracking at less than 5,000 cycles

(Example 7)
Example 2 except that 100 parts of solid content of PUD2 was changed to 80 parts of solid content of PUD2 and 20 parts of acrylic resin (Movinyl 6530 (manufactured by Japan Coating Resin Co., Ltd., solid content: 44%, Tg = 30 ° C.)). In the same manner as above, an aqueous surface treatment agent was obtained. Using this water-based surface treatment agent, gloss measurement, thermal shrinkage resistance evaluation, plane abrasion test, and cold bending resistance test were performed in the same manner as in Example 2. In addition, a flat wear II test described below was also conducted. The results are shown in Table 4 below.

<Plane wear II>
The conditions of the plane wear test performed in Example 1 were changed as follows.
The pressing load including the scraper was 9.81 N (1 kgf), the stroke was 140 mm, and the speed was 60±10 reciprocations/min. 30,000 reciprocating tests were conducted as The evaluation indices were as follows.
A: No change in appearance B: 1 or more but less than 10 identifiable scratches C: 10 or more identifiable scratches For comparison, the surface wear II test was also performed on Example 2.

(Example 8)
Example 2 except that the polyurethane resin particles (ARTPEARL C-400 transparent) were changed to polyurethane resin particles (ARTPEARL C-800 transparent (manufactured by Negami Kogyo Co., Ltd., volume average particle diameter 6 μm, Tg=−13° C.)) In the same manner as above, an aqueous surface treatment agent was obtained. Using this water-based surface treatment agent, gloss measurement, thermal shrinkage resistance evaluation, flat abrasion test, flat abrasion II test, and cold bending resistance test were carried out in the same manner as in Example 7. The results are shown in Table 4 below.

(Example 9)
An aqueous surface treatment agent was obtained in the same manner as in Example 2, except that the oxazoline crosslinking agent was changed to a carbodiimide crosslinking agent (Carbodilite V-02 (manufactured by Nisshinbo Chemical Co., Ltd.). Measurement of gloss, evaluation of heat shrinkage resistance, flat abrasion test, flat abrasion II test, and cold bending resistance test were carried out in the same manner as in Example 7. The results are shown in Table 4 below.

(Example 10)
100 parts of solid content of PUD2 was changed to 80 parts of solid content of PUD2 and polyvinyl chloride resin (Vinyblan 278 (manufactured by Nissin Chemical Co., Ltd., solid content 43%, Tg = 30 ° C.)) 20 parts An aqueous surface treatment agent was obtained in the same manner as in Example 2. Using this water-based surface treatment agent, gloss measurement, thermal shrinkage resistance evaluation, flat abrasion test, flat abrasion II test, and cold bending resistance test were carried out in the same manner as in Example 7. The results are shown in Table 4 below.

The water-based surface treatment agent of the present invention is particularly useful for automobile interior parts, railway vehicle/aircraft interior parts, furniture, shoes/footwear/bags, interior/exterior materials for building decoration, clothing covering materials/linings, wall covering materials, and the like. It can be used as an imparting paint.

Claims (5)

It contains a polyurethane resin having a 100% modulus of 6 to 17 MPa measured at 23° C. and 50% humidity and a thermal softening point of 30 to 55° C. measured at 23° C. and 50% humidity, wherein the polyurethane resin is modified with siloxane. water-based surface treatment agent. 2. The aqueous surface treating agent according to claim 1, which contains a matting agent. 3. The aqueous surface treating agent according to claim 1, containing at least one selected from the group consisting of acrylic resins and polyvinyl chloride resins. The aqueous surface treatment agent according to any one of claims 1 to 3, which contains an oxazoline-based cross-linking agent. A skin material comprising a base material and a film comprising the surface treatment agent according to any one of claims 1 to 4.