JP7031660B2 - Manufacturing method of paint for vehicle interior parts, vehicle interior parts and vehicle interior parts - Google Patents

Description

The present invention relates to a paint for a vehicle interior member, a vehicle interior member, and a method for manufacturing the vehicle interior member.

Vehicle interior components (dashboard (instrument panel), center console, door trim, center cluster, switch panel, shift knob, etc.) are hardened by curing the paint for the purpose of protecting the surface, decorating or improving the feel. May have a membrane. Such a paint is used by directly painting on a vehicle interior base material constituting a vehicle interior member or by applying the paint to a film used by being attached to the vehicle interior base material.
In the vehicle interior member, contamination of the member due to the adhesion of the sunscreen may be a problem, and the vehicle interior member is required to have stain resistance.
Patent Document 1 discloses a film for a vehicle interior member using a fluorine-containing polymer.

Japanese Unexamined Patent Publication No. 2014-139919

Further, the vehicle interior member is also required to have excellent scratch resistance.
As a result of studying the prior art, the present inventors have found that both stain resistance and scratch resistance to sunscreen agents cannot be achieved at the same time.

The present invention has been made in view of the above problems, and is a paint for a vehicle interior member capable of forming a vehicle interior member having excellent scratch resistance and stain resistance to a sunscreen agent, and is formed by using the paint. An object of the present invention is to provide a vehicle interior member having a cured film and a method for manufacturing the same.

As a result of diligent studies on the above problems, the present inventors can obtain a desired effect when a coating material containing a fluoropolymer having a crosslinkable group, a polyrotaxane having a crosslinkable group, and a curing agent is used. This led to the present invention.
That is, the present inventors have found that the above problem can be solved by the following configuration.

(1) A fluoropolymer containing a unit based on a fluoroolefin and a unit based on a monomer having a first crosslinkable group, a polyrotaxane having two or more second crosslinkable groups, and the first crosslinkability. A coating material for vehicle interior members, which comprises a curing agent having two or more functional groups capable of reacting with at least one of the group and the second crosslinkable group.
(2) The coating material according to (1), wherein the fluorine-containing polymer has a glass transition temperature of 50 ° C. or higher.
(3) The fluoropolymer further contains a unit based on a monomer having an alkyl group having a tertiary carbon atom having 3 to 9 carbon atoms or a cycloalkyl group having 4 to 10 carbon atoms in a side chain. The coating material according to (1) or (2), wherein the content of the unit is 10 to 45 mol% with respect to all the units contained in the fluoropolymer.
(4) The content of the unit based on the monomer having the first crosslinkable group is 1 to 40 mol% with respect to all the units contained in the fluorine-containing polymer (1) to (3). The paint described in any of.
(5) The coating material according to any one of (1) to (4), wherein the first crosslinkable group is a hydroxy group and the hydroxyl value of the fluorine-containing polymer is 1 to 150 mgKOH / g.

(6) The coating material according to any one of (1) to (5), wherein the ratio of the mass of the fluorine-containing polymer to the mass of the polyrotaxane is 1.5 or more.
(7) The coating material according to any one of (1) to (6), wherein the glass transition temperature of the polyrotaxane is 0 ° C. or lower.
(8) The polyrotaxane is a polyrotaxane having cyclodextrin as a cyclic molecule and polyethylene glycol having both ends sealed with a blocking group as a shaft molecule, or a cyclic ester-modified product or a cyclic ether-modified product of the polyrotaxane (1). )-(7).
(9) The coating material according to any one of (1) to (8), wherein the second crosslinkable group is a hydroxy group or a carboxy group.
(10) The coating material according to (9), wherein the second crosslinkable group is a hydroxy group and the hydroxyl value of the polyrotaxane is 200 mgKOH / g or less.

(11) The coating material according to any one of (1) to (10), wherein the weight average molecular weight of the shaft molecule of the polyrotaxane is 1,000 or more.
(12) The coating material according to any one of (1) to (11), wherein the content of the polyrotaxane is 0.1 to 30% by mass with respect to the total amount of the fluorine-containing polymer, the polyrotaxane and the curing agent. ..
(13) The method according to any one of (1) to (12), wherein both the first crosslinkable group and the second crosslinkable group are hydroxy groups, and the curing agent is an isocyanate-based curing agent. paint.
(14) A vehicle interior member having a vehicle interior base material and a cured film formed from the paint according to any one of (1) to (13) arranged on the vehicle interior base material.
(15) A vehicle interior member in which the paint according to any one of (1) to (13) is applied onto a vehicle interior base material to form a coating film, and the coating film is cured to form a cured film. Manufacturing method.

According to the present invention, a paint for a vehicle interior member capable of forming a vehicle interior member having excellent scratch resistance and stain resistance to a sunscreen agent, and a vehicle interior member having a cured film formed by using this paint and the vehicle interior member. The manufacturing method can be provided.

The meanings of the terms in the present invention are as follows.
The "unit" is a general term for an atomic group derived from one molecule of the monomer, which is directly formed by polymerizing a monomer, and an atomic group obtained by chemically converting a part of the atomic group. be. The content (mol%) of each unit with respect to all the units contained in the polymer can be determined from the amount of each monomer charged.
The "acid value" and the "hydroxyl value" are values measured according to the method of JIS K 0070-3 (1992), respectively.
The "glass transition temperature" is a value measured by the method specified in JIS K 6240 (2011). The "glass transition temperature" is also referred to as "Tg".
The "number average molecular weight" and the "weight average molecular weight" are values measured by gel permeation chromatography using polystyrene as a standard substance. The "number average molecular weight" is also referred to as "Mn", and the "weight average molecular weight" is also referred to as "Mw".
The "fluorine content" means the ratio (mass%) of fluorine atoms to the total mass of the fluorine-containing polymer. The fluorine content is determined by analyzing the fluorine-containing polymer by the nuclear magnetic resonance spectral method.

The paint for vehicle interior members of the present invention (hereinafter, also referred to as “the paint”) has a crosslinkable fluorine-containing weight including a unit based on a fluoroolefin and a unit based on a monomer having a first crosslinkable group. It is a coating material containing a combination, a crosslinkable polyrotaxane having two or more second crosslinkable groups, and a curing agent. In the following, the term "contamination resistance" refers to stain resistance to sunscreens such as Copatone (registered trademark).
The present inventors have found that a vehicle interior member containing a cured film formed from the present paint containing a crosslinkable fluorine-containing polymer and a crosslinkable polyrotaxane can achieve both scratch resistance and stain resistance at a high level. ing. Further, as shown in Examples described later, a vehicle interior member having a cured film of a paint containing a crosslinkable fluoropolymer and a crosslinkable polymer other than the crosslinkable polyrotaxane has deteriorated stain resistance. I also know that it will end up.

The fluorine-containing polymer in the present invention has a fluoroolefin-based unit (hereinafter, also referred to as “unit F”) and a monomer having a first crosslinkable group (hereinafter, also referred to as “monomer C”). A fluoropolymer having a first crosslinkable group, which comprises a unit based on (hereinafter, also referred to as “unit C”).

A fluoroolefin is an olefin in which one or more hydrogen atoms are substituted with a fluorine atom. In the fluoroolefin, one or more hydrogen atoms which are not substituted with a fluorine atom may be substituted with a chlorine atom.
Specific examples of fluoroolefins include CF ₂ = CF ₂ , CF ₂ = CFCF ₃ , CF ₂ = CFCl, and CH ₂ = CF ₂ . The fluoroolefin is preferably CF ₂ = CF ₂ and CF ₂ = CFCl from the viewpoint of weather resistance of the cured film (hereinafter, also referred to as “main cured film”) formed from the present coating material.
Two or more kinds of fluoroolefins may be used in combination.
The content of the unit F is preferably 20 to 70 mol%, particularly preferably 40 to 60 mol%, based on all the units contained in the fluorine-containing polymer, from the viewpoint of the weather resistance of the cured film.

The first crosslinkable group of the monomer C is a functional group having an active hydrogen (hydroxy group, carboxy group, amino group, etc.) or a hydrolyzable silyl group (alkoxysilyl) from the viewpoint of curability of the cured film. Groups, etc.) are preferred, hydroxy or carboxy groups are more preferred, and hydroxy groups are particularly preferred.
Specific examples of the monomer C include hydroxyalkyl vinyl ether, hydroxycycloalkyl vinyl ether, hydroxyalkyl vinyl ester, hydroxycycloalkyl vinyl ester, hydroxyalkyl allyl ether, hydroxyalkyl allyl ester, acrylic acid hydroxyalkyl ester, and hydroxyalkyl methacrylate. Ester can be mentioned. Among them, hydroxyalkyl vinyl ether and hydroxyalkyl allyl ether are preferable, and 4-hydroxybutyl vinyl ether and 2-hydroxyethyl allyl ether are more preferable, from the viewpoint of curability of the present cured film.
Two or more kinds of monomer C may be used in combination.

The content of the unit C is preferably 1 to 40 mol%, more preferably 5 to 15 mol%, based on all the units contained in the fluorine-containing polymer, from the viewpoint of scratch resistance and stain resistance of the cured film.

The fluoropolymer in the present invention has an alkyl group having a tertiary carbon atom having 3 to 9 carbon atoms or 4 to 10 carbon atoms from the viewpoint of being able to form the cured film having a high Tg and excellent impact resistance. It is preferable to contain a unit (hereinafter, also referred to as “unit T”) based on a monomer having a cycloalkyl group in the side chain (hereinafter, also referred to as “monomer T”). The monomer T does not contain either a fluorine atom or a crosslinkable group.
Specific examples of the alkyl group and the cycloalkyl group include a tert-butyl group, a neononyl group, a cyclohexyl group, a cyclohexylmethyl group, a 4-cyclohexylcyclohexyl group and a 1-decahydronaphthyl group.
The monomer T is a vinyl ether, an allyl ether, a vinyl ester, an allyl ester, an acrylic acid ester or a methacrylic acid ester, and is an alkyl group having a tertiary carbon atom having 3 to 9 carbon atoms or a cyclo having 4 to 10 carbon atoms. Monomers having an alkyl group in the side chain are preferable.
Specific examples of the monomer T include cyclohexyl vinyl ether, tert-butyl vinyl ether, tert-butyl vinyl ester, and neononanoic acid vinyl ester.
Two or more kinds of monomer T may be used in combination.
The content of the unit T is preferably 10 to 45 mol%, more preferably 12 to 40 mol%, and 15 to 15 to all the units contained in the fluorine-containing polymer from the viewpoint of adjusting the Tg of the fluorine-containing polymer. 35 mol% or 36-40 mol% is particularly preferable, and 36-40 mol% is particularly preferable.

The fluorine-containing polymer is further referred to as a unit other than the unit F, the unit C and the unit T (a unit based on the monomer F, the monomer C and the monomer other than the monomer T; hereinafter, also referred to as “unit H”. ) May be included.
Specific examples of the monomer constituting the unit H include alkyl vinyl ether (nonyl vinyl ether, hexyl vinyl ether, ethyl vinyl ether, n-butyl vinyl ether, etc.), alkyl allyl ether (ethyl allyl ether, hexyl allyl ether, etc.), and carboxylic acid. Examples thereof include vinyl esters of (acetic acid, butyric acid, propionic acid, etc.) and allyl esters of carboxylic acids (acetic acid, butyric acid, propionic acid, etc.).
Two or more such monomers may be used in combination.
The content of the unit H is preferably 50 mol% or less, more preferably 30 mol% or less, based on all the units contained in the fluorine-containing polymer.

The fluorine-containing polymer in the present invention has a unit F, a unit C, a unit T, and a unit H, respectively, with respect to all the units contained in the fluorine-containing polymer, from the viewpoint of weather resistance and scratch resistance of the cured film. In this order, it is preferably 20 to 70 mol%, 1 to 40 mol%, 10 to 45 mol%, and 0 to 50 mol%.
The Mn of the fluorine-containing polymer is preferably 3,000 to 50,000, more preferably 5,000 to 30,000, and particularly preferably 5,000 to 20,000.
When the fluorine-containing polymer has a hydroxy group, the hydroxyl value of the fluorine-containing polymer is preferably 1 to 150 mgKOH / g, more preferably 1 to 100 mgKOH / g, and particularly preferably 15 to 50 mgKOH / g.
The fluorine content of the fluorine-containing polymer is preferably 10 to 70% by mass, more preferably 20 to 60% by mass, and particularly preferably 20 to 30% by mass from the viewpoint of stain resistance and weather resistance of the cured film. When the fluorine content of the fluorine-containing polymer is 10% by mass or more, the weather resistance of the cured film is more excellent. When the fluorine content of the fluorine-containing polymer is 70% by mass or less, the surface smoothness of the cured film is excellent.
The Tg of the fluorine-containing polymer is preferably 35 ° C. or higher, more preferably 50 ° C. or higher, from the viewpoint of stain resistance of the cured film. The Tg of the fluorine-containing polymer is preferably 150 ° C. or lower, more preferably 120 ° C. or lower, and particularly preferably 100 ° C. or lower.

The content of the fluorine-containing polymer in the present coating material is 20 to 80 with respect to the total amount of the fluorine-containing polymer, polyrotaxane and the curing agent of the coating material of the present invention from the viewpoint of stain resistance and weather resistance of the cured film. The mass% is preferable, and 25 to 75% by mass is more preferable.
The ratio of the mass of the fluorinated polymer to the mass of the polyrotaxane in this coating material (mass of the fluorinated polymer / mass of polyrotaxane) has stain resistance and scratch resistance of the cured film, and is also stretchable. From an excellent viewpoint, it is preferably 1.5 or more, more preferably 2.0 to 90, and particularly preferably 3.0 to 30.

The polyrotaxane in the present invention is a crosslinkable polyrotaxane having a second crosslinkable group. The crosslinkable polyrotaxane may be directly crosslinked (bonded) with the fluorine-containing polymer, or may be crosslinked with the fluorine-containing polymer via a curing agent described later.
Polyrotaxane is a pseudopolyrotaxane in which the opening of a cyclic molecule such as cyclodextrin is pierced in a skewered manner by a linear shaft molecule, and a plurality of cyclic molecules enclose the shaft molecule (both ends of the shaft molecule). It is a molecular complex in which a blocking group is arranged so that the cyclic molecule is not released. That is, the polyrotaxane has a cyclic molecule, an axial molecule that encloses the cyclic molecule in a skewered manner, and a blocking group that is arranged at both ends of the axial molecule and prevents the cyclic molecule from being detached.
In addition to the above-mentioned molecular complex, the polyrotaxane also includes a crosslinked product in which the above-mentioned molecular complexes are crosslinked with each other at a cyclic molecular portion. Further, in the present specification, the polyrotaxane also includes an embodiment in which a cyclic molecule such as cyclodextrin is modified to improve compatibility and solubility.

In polyrotaxanes, cyclic molecules are free to move on the axis molecule. Thus, for example, when the cyclic molecule has a crosslinkable group, the crosslinkable group on the cyclic molecule also moves with the free movement of the cyclic molecule, so that the crosslinked structure formed by polyrotaxane is flexible to the impact applied. Can be dealt with. That is, the crosslinked structure can exert a force to correct the disorder of the crosslinked structure caused by the impact without being destroyed by the impact (hereinafter, this effect is also referred to as "self-repairing property"). Therefore, it is considered that the curability of the cured film is improved by the cross-linking between the polyrotaxane and the fluorine-containing polymer, and the scratch resistance of the cured film is excellent due to the excellent self-repairing property of the cross-linked structure formed by the poly rotaxane.

The axis molecule constituting the polyrotaxane is not particularly limited as long as it is a linear molecule that is encapsulated in a cyclic molecule and can be integrated with the cyclic molecule in a non-covalent bond.
Also, the "straight line" of a shaft molecule that is linear means that it is substantially "straight line". That is, the axial molecule may have a branched chain as long as the cyclic molecule which is a rotor is rotatable or the cyclic molecule is slidable on the axial molecule. Further, the length of the "straight line" is not particularly limited as long as the cyclic molecule can slide or move on the axis molecule.

The Mw of the shaft molecule is preferably 1,000 or more, more preferably 5,000 or more, and particularly preferably 10,000 or more. The Mw of the axis molecule is preferably 100,000 or less, more preferably 50,000 or less, and particularly preferably 40,000 or less. When the Mw of the shaft molecule contained in the polyrotaxane is 1,000 or more, the compatibility between the polyrotaxane and the fluorine-containing polymer is excellent, and the curability of the cured film is improved, so that the scratch resistance of the cured film is further improved. Cheap. When the Mw of the shaft molecule contained in the polyrotaxane is 100,000 or less, the fluorine-containing polymers crosslinked via the polyrotaxane become dense, and the stain resistance of the cured film is further improved.

The linear shaft molecules constituting polyrotaxane include polycaprolactone, styrene-butadiene copolymer, isobutene-isoprene copolymer, polyisobutylene, natural rubber, polyalkylene glycol, polyisobutylene, polybutadiene, polypropylene glycol, and polytetrachloride. , Polydimethylsiloxane, polyethylene, polypropylene, ethylene-polypropylene copolymer and the like. The shaft molecule is preferably polyethylene glycol, polypropylene glycol, polytetrahydrofuran, polyethylene glycol-polypropylene glycol copolymer, polyisobutylene, polyisobutylene, polybutadiene, polydimethylsiloxane, polyethylene and polypropylene. A particularly preferred axis molecule is polyethylene glycol.
Specific examples of the blocking group that blocks both ends of the shaft molecule include a dinitrophenyl group, an adamantyl group, a trityl group, fluorescein, and pyrene. For example, the terminal hydroxy group of polyethylene glycol can be converted to a carboxy group and reacted with 1-adamantanamine to block both ends of polyethylene glycol.

The cyclic molecule constituting the polyrotaxane can be any cyclic molecule as long as it can include the axial molecule.
Specific examples of the cyclic molecule include cyclodextrin (α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, dimethylcyclodextrin, glucosylcyclodextrin, etc.), crown ether, benzocrown, dibenzocrown, and dicyclohexanocrown. , And derivatives of these. As the cyclic molecule, cyclodextrin is particularly preferable.

The crosslinkable group contained in the polyrotaxane may be contained in a cyclic molecule, may be contained in an axial molecule, and is preferably possessed by a cyclic molecule.
If the cyclic molecule is cyclodextrin, it has a hydroxy group, and this hydroxy group can also be converted to another crosslinkable group. Further, a crown ether having a crosslinkable group or the like can also be used.
Since a polyrotaxane usually contains a plurality of cyclic molecules in one axis molecule, when the cyclic molecule has a crosslinkable group, the polyrotaxane has two or more crosslinkable groups. Further, even when the blocking group of the shaft molecule has a crosslinkable group, the polyrotaxane has two or more crosslinkable groups because the blocking group is present at both ends of the shaft molecule.

As the polyrotaxane having a second crosslinkable group, an ester-modified product or an ether-modified product obtained by ring-opening and adding a cyclic ester or a cyclic ether to a polyrotaxan having a cyclic molecule having a functional group such as a hydroxy group can also be used. .. For example, a modified product obtained by ring-opening addition of a cyclic ester or a cyclic ether to a hydroxyl group of cyclodextrin, which is a cyclic molecule, is known (see, for example, Japanese Patent Application Laid-Open No. 2007-91938), and this modified product is used as a second product. It can be used as a polyrotaxane having a crosslinkable group of. The group produced by ring-opening addition of a cyclic ester or cyclic ether to the hydroxy group of cyclodextrin is a group having a hydroxy group at the terminal.
Examples of the cyclic ether include alkylene oxides such as ethylene oxide and propylene oxide. Examples of the cyclic ester include ε-caprolactone, γ-butyrolactone, δ-valerolactone and the like.

The second crosslinkable group in the polyrotaxane is preferably a hydroxy group and a carboxy group, and a hydroxy group is preferable from the viewpoint of crosslinkability with a curing agent.
When the crosslinkable group of the polyrotaxane is a hydroxy group, the hydroxyl value of the polyrotaxane is preferably 200 mgKOH / g or less, more preferably 10 to 200 mgKOH / g, and further preferably 50 to 150 mgKOH / g. It is preferably 50 to 100 mgKOH / g, and particularly preferably 50 to 100 mgKOH / g. When the hydroxyl value of the polyrotaxane is 10 mgKOH / g or more, the scratch resistance of the cured film is excellent, and when it is 200 mgKOH / g or less, the water resistance of the cured film is excellent.

The Tg of the polyrotaxane is preferably 0 ° C. or lower, more preferably 0 ° C. or lower and −60 ° C. or higher, from the viewpoint of compatibility with the fluorine-containing polymer.
The content of polyrotaxane in the present coating material is preferably 0.1 to 30% by mass, preferably 1 to 30% by mass, based on the total amount of the fluoropolymer, the polyrotaxane and the curing agent of the present coating material from the viewpoint of the scratch resistance of the main coating film. 20% by mass is more preferable, and 5 to 15% by mass is particularly preferable.

The curing agent in the present invention is a compound having two or more functional groups capable of reacting with both the first crosslinkable group and the second crosslinkable group. The number of functional groups in the curing agent is usually 30 or less.

Specific examples of the curing agent include isocyanate-based curing agents, amine-based curing agents (melamine resin, guanamine resin, sulfoamide resin, urea resin, aniline resin, etc.), β-hydroxyalkylamide-based curing agents, and epoxy-based curing agents (epoxy-based curing agents). Triglycidyl isocyanurate-based curing agents, etc.), carbodiimide-based curing agents, and the like. Two or more kinds of curing agents may be used in combination.
When the fluorine-containing polymer has a hydroxy group and polyrotaxane has a hydroxy group, the curing agent is preferably an isocyanate-based curing agent from the viewpoint of adhesion between the cured film and the substrate and the curability of the coating material. ..
Specific examples of the isocyanate-based curing agent include a curing agent having two or more isocyanate groups and a curing agent having two or more blocked isocyanate groups (hereinafter, also referred to as “blocked isocyanate-based curing agent”). Can be mentioned.

Specific examples of the former curing agent include alicyclic polyisocyanates such as isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), methylcyclohexanediisocyanate, and bis (isocyanatomethyl) cyclohexane, and hexa. Examples thereof include aliphatic polyisocyanates such as methylene diisocyanate (HDI), diisocyanate dimerate, and lysine diisocyanate, and modified forms (biuret form, isocyanurate form, adduct form, etc.) of these compounds.
The adduct is a compound having an isocyanate group, which is obtained by reacting polyisocyanate with a small molecule compound having active hydrogen. Examples of the small molecule compound having active hydrogen include water, polyhydric alcohols, polyamines, alkanolamines and the like. Specific examples thereof include ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, ethylenediamine, ethanolamine, and diethanolamine. As the small molecule compound having active hydrogen, a polyhydric alcohol is particularly preferable.
Among them, the adduct body of the above compound is preferable, the adduct body of the aliphatic polyisocyanate is more preferable, and the adduct body of HDI is particularly preferable, from the viewpoint of obtaining a cured film having elasticity and less generation of cracks.

The blocked isocyanate-based curing agent can be produced by reacting the above-mentioned polyisocyanate with the blocking agent.
Specific examples of the blocking agent include alcohols (methanol, ethanol, benzyl alcohol, etc.), phenols (phenol, crezone, etc.), lactams (caprolactam, butyrolactam, etc.), and oximes (cyclohexanone, oxime, methylethylketooxime, etc.). Can be mentioned.

The content of the curing agent is preferably 10 to 200 parts by mass, more preferably 30 to 170 parts by mass, and particularly preferably 50 to 150 parts by mass with respect to 100 parts by mass of the fluorine-containing polymer in the present coating. When the content of the curing agent is within the above range, the cross-linking between the fluorine-containing polymer and the polyrotaxane proceeds satisfactorily.

The present coating may contain a curing catalyst.
The curing catalyst is a compound that promotes the curing reaction when the above-mentioned curing agent is used, and can be selected from known curing catalysts depending on the type of the curing agent. The content of the curing catalyst is preferably 0.00001 to 0.01 parts by mass with respect to 100 parts by mass of the amount of the curing agent added.

The present paint may contain components other than the above, if necessary. Specific examples of components other than the above include dispersion media and solvents (water, organic solvents, etc.), ultraviolet absorbers, light stabilizers (hindered amine light stabilizers, etc.), matting agents (ultrafine powder synthetic silica, etc.), leveling agents, and the like. Surface conditioners, surfactants, degassing agents, plasticizers, fillers, heat stabilizers, thickeners, dispersants, antistatic agents, rust preventives, silane coupling agents, antifouling agents, decontamination treatment Agents are mentioned.

This paint can be used as a solution type (that is, a paint containing a solvent capable of dissolving a fluorine-containing polymer or the like), an aqueous dispersion type, or a powder type (that is, a powder paint containing substantially no solvent). , Solution type is preferred, and paints containing organic solvents are more preferred.
In the powder type, the content of the solvent in the coating material is 1% by mass or less, preferably 0.5% by mass or less, and particularly preferably 0% by mass, based on the total mass of the coating material.

A known method can be adopted as the method for producing the present paint. The solution type paint is produced by dissolving each of the above-mentioned components in a solvent using, for example, a stirrer such as a disper. The powder type paint is produced, for example, by melting and kneading a powdery mixture in which each component is mixed in advance with an extruder, cooling the extruded kneaded product, and then pulverizing the mixture.

The method for manufacturing a vehicle interior member of the present invention is a method in which the present paint is applied onto a vehicle interior base material to form a coating film, and the coating film is cured to form the present cured film. By this method, a vehicle interior member having a vehicle interior base material and the main cured film arranged on the vehicle interior base material can be obtained. Since the vehicle interior member thus obtained has the present cured film, it is excellent in scratch resistance and stain resistance.
Specific examples of vehicle interior members include dashboards (instrument panels), center consoles, door trims, center clusters, switch panels, and shift knobs.

The present paint may be applied directly to the vehicle interior base material, or may be applied to a film used by being attached to the vehicle interior base material. When the film used to be attached to the vehicle interior base material is coated, the film on which the cured film is formed is attached to the vehicle interior base material in the method for manufacturing the vehicle interior member of the present invention. ..

Specific examples of the material constituting the vehicle interior base material include polycarbonate resin, acrylic resin, methacrylic resin, acrylonitrile-butadiene-styrene copolymer, polystyrene, polypropylene, and polyester resin (polybutylene terephthalate, polybutylene terephthalate).
Specific examples of the materials constituting the film include polycarbonate resin, acrylic resin, methacrylic resin, ABS resin, polyolefin resin (polyethylene, polypropylene, etc.), polyvinyl chloride resin (polyvinyl chloride, polyvinylidene chloride, polyvinyl chloride, etc.). (Polyvinyl chloride vinylidene, etc.), polyester resin (polyethylene terephthalate, polybutylene terephthalate, etc.), polyamide resin (nylon 6, nylon 66, MXD nylon (methoxylenidamine-adipic acid copolymer), etc.), weight of olefin having a substituent Examples thereof include coalescence, EVA (ethylene-vinyl alcohol copolymer), ethylene-tetrafluoroethylene copolymer, etc.). The film may be a combination of two or more of these materials.

Specific examples of the application method of this paint include sponge coating method, spray coating method, curtain coating (flow coating), roll coating method, casting method, dip coating method, spin coating method, die coating method, electrostatic coating method, and static coating method. Examples thereof include an electric spray method, an electrostatic dipping method, and a flow dipping method.
Examples of the method for drying the coating film containing a solvent include natural drying, vacuum drying, centrifugal drying, heat drying and the like, and heat drying is preferable from the viewpoint of combining the curing treatment described later.
The drying temperature of the coating film containing the solvent is preferably 15 to 45 ° C., more preferably 20 to 40 ° C. from the viewpoint of sufficiently volatilizing the solvent. The drying time is preferably 15 minutes to 14 days, more preferably 30 minutes to 10 days.
Examples of the method for curing the coating film include heat treatment. In this case, the heating temperature is preferably 40 ° C. to 200 ° C., more preferably 45 ° C. to 150 ° C. from the viewpoint that bubbles and the like are less likely to be generated in the cured film. The heating time is preferably 1 minute to 3 hours, more preferably 3 minutes to 2 hours.

The film thickness of the cured film is preferably 5 to 150 μm, more preferably 10 to 100 μm. When the film thickness of the cured film is 5 μm or more, the scratch resistance and stain resistance of the cured film are more exhibited, and when the film thickness is 150 μm or less, the weight of the vehicle interior member can be reduced.

The vehicle interior member of the present invention has the vehicle interior base material and a cured film formed from the present paint arranged on the vehicle interior base material. Since the vehicle interior member of the present invention has a cured film of the present paint, it is excellent in scratch resistance and stain resistance. The vehicle interior member of the present invention can be manufactured, for example, by the above-described method for manufacturing a vehicle interior member.

Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to these examples. The blending amount of each component in the table described later indicates a mass standard. Further, Examples 1 to 3 and Examples 6 to 9 are Examples, and Examples 4 to 5 are Comparative Examples.

[Production example of fluorine-containing polymer 1]
In an autoclave, cyclohexyl vinyl ether (CHVE) (51.2 g), 4-hydroxybutyl vinyl ether (HBVE) (13.3 g), xylene (55.8 g), ethanol (15.7 g), potassium carbonate (1.1 g), A 50 mass% xylene solution (0.7 g) of tert-butyl peroxypivalate (PBPV) and chlorotrifluoroethylene (CTFE) (63 g) were introduced and polymerized at 65 ° C. for 15 hours with stirring. The solution in the autoclave was filtered, and the obtained filtrate was distilled off under reduced pressure to obtain a fluorine-containing polymer 1.
The fluorine-containing polymer 1 contains 50 mol%, 39 mol%, and 11 mol% of CTFE-based units, CHVE-based units, and HBVE-based units in this order with respect to all the units contained in the fluorine-containing polymer 1. It was a polymer.
The fluorine-containing polymer 1 had a Tg of 55 ° C., a fluorine content of 23.7% by mass, a hydroxyl value of 50 mgKOH / g, and a Mn of 12,000.

[Production example of fluorine-containing polymer 2]
The same as in the production example of the fluorine-containing polymer 1 except that the monomer used in the production example of the fluorine-containing polymer 1 and ethyl vinyl ether (EVE) are used and the amount of each monomer is adjusted. Fluorine polymer 2 was obtained. The fluorine-containing polymer 2 contains 50 mol% and 15 mol% of CTFE-based units, CHVE-based units, HBVE-based units, and EVE-based units in this order with respect to all the units contained in the fluorine-containing polymer 2. It was a polymer containing 10 mol% and 25 mol%.
The fluorine-containing polymer 2 had a Tg of 37 ° C., a fluorine content of 26.7% by mass, a hydroxyl value of 53 mgKOH / g, and a Mn of 20,000.

[Manufacturing of paint]
Each component shown in Table 1 was mixed so as to have a blending amount (part by mass) shown in Table 1 described later to obtain each coating material of Examples 1 to 9. The outline of each component is shown below.

<Fluorine-containing polymer solution>
The fluorine-containing polymer solution 1 is a solution in which the fluorine-containing polymer 1 is dissolved in butyl acetate. The numerical values in parentheses in Table 1 indicate the amount (parts by mass) of the fluorine-containing polymer 1 contained in the fluorine-containing polymer solution.
-The fluorine-containing polymer solution 2 is a solution in which the fluorine-containing polymer 2 is dissolved in butyl acetate. The numerical values in parentheses in Table 1 indicate the amount (parts by mass) of the fluorine-containing polymer 2 contained in the fluorine-containing polymer solution.
<Polyrotaxane>
-CELM Super Polymer SH2400P (manufactured by Advanced Soft Materials Co., Ltd., polyrotaxane having a hydroxyl group, Mw of a shaft molecule: 20,000, hydroxyl value: 76 mgKOH / g, Tg: -50 ° C). This polyrotaxane is a polyrotaxane obtained by modifying polyrotaxane having a polyethylene glycol chain having a cyclodextrin as a cyclic molecule and an adamantyl group as a blocking group with propylene oxide and ε-caprolactone (Japanese Patent Laid-Open No. 2007-91938). See examples in the publication).
<Polycarbonate polyol>
Duranol T-5650E (manufactured by Asahi Kasei Corporation, Mn: 500, hydroxyl value: 200 mgKOH / g, Tg: -50 ° C or less)
<Curing agent>
-Curing agent 1: Coronate HX (manufactured by Nippon Polyurethane Industry Co., Ltd., isocyanurate-modified HDI type polyisocyanate-based curing agent, solid content 100% by mass)
-Curing agent 2: Duranate E405-70B (manufactured by Asahi Kasei Corporation, butyl acetate solution of HDI adduct type polyisocyanate type curing agent, solid content 70% by mass). The numerical values in parentheses in Table 1 indicate the solid content (parts by mass) of E405-70B.
<Curing catalyst>
DBTDL solution: Butyl acetate solution of dibutyltin dilaurate (diluted 10,000 times). The numerical values in parentheses in Table 1 indicate the solid content (parts by mass) of the DBTDL solution.

[Evaluation test]
<Preparation of test piece>
Each paint is applied on an acrylic resin film with a bar coater to form a coating film, then heat-dried at 25 ° C for 30 minutes, and heat-treated at 80 ° C for 10 minutes to form the paint on the film. A test piece having a cured film (thickness 50 μm) was obtained.
Using the obtained test piece, it was evaluated as follows.

<Stain resistance (sun oil resistance)>
One drop (0.005 g) of sunscreen (Copatone Water Babys Lotion SPF50) was dropped on the cured film of the test piece, spread over a range of 2 cm x 3 cm using a brush, and then 5 pieces of gauze were applied. It was placed and left at 80 ° C. for 1 hour. Then, the sunscreen was wiped off with gauze, the test piece was washed with water, and the change in the cured film was visually observed. The evaluation criteria are as follows.
A: No change is observed in the cured film.
B: Fine paint marks are observed on the cured film.
C: The surface of the cured film is severely deteriorated, and coating marks are clearly observed.

<Scratch resistance 1>
After rubbing the surface of the cured film of the test piece 15 times with a load of 200 g using steel wool (# 0000), the surface was visually observed and evaluated according to the following criteria.
A: It wasn't scratched.
B: Slight scratches are observed, which is less than 20% of the area of the test piece.
C: Many scratches are observed, which is 20% or more of the area of the test piece.

<Scratch resistance 2>
After rubbing the surface of the cured film of the test piece 15 times with a load of 300 g using steel wool (# 0000), the surface was visually observed and evaluated according to the following criteria.
A: It wasn't scratched.
B: Slight scratches are observed, which is less than 20% of the area of the test piece.
C: Many scratches are observed, which is 20% or more of the area of the test piece.

<Growth>
Using Autograph AGS10KNG (manufactured by Shimadzu Corporation) and TERMOSTATIC CHAMBER Model: TCRI-200SP (manufactured by Shimadzu Corporation), the test piece size is 10 mm x 100 mm, the chuck distance is 50 mm, the tensile speed is 50 mm / min, and the temperature of the tensile constant temperature bath is 23 ° C. When the tensile test was performed under the conditions, the elongation rate of the test piece until cracks were generated in the cured film was visually confirmed.
S: The elongation of the test piece is 150% or more with respect to the test piece before the tensile test.
A: The elongation of the test piece is 100% or more and less than 150% with respect to the test piece before the tensile test.
B: The elongation of the test piece is 50% or more and less than 100% with respect to the test piece before the tensile test.
C: The elongation of the test piece is less than 50% with respect to the test piece before the tensile test.

<Evaluation result>
The results of the above evaluation tests are shown in Table 1.

As shown in Table 1, it was shown that the cured film formed from the paint containing the fluorine-containing polymer and the polyrotaxane has excellent scratch resistance and stain resistance to sunscreens.
Further, the result of applying the paint composition produced in Examples 1 to 3 described above onto a dashboard (instrument panel), a center console, a door trim, a center cluster, a switch panel, or a shift knob to form a cured film. In each case, the scratch resistance and the stain resistance were excellent.
The entire contents of the specification, claims and abstract of Japanese Patent Application No. 2017-049467 filed on March 15, 2017 are cited here and incorporated as disclosure of the specification of the present invention. Is.

Claims (14)

A fluorine-containing polymer containing a unit based on a fluoroolefin and a unit based on a monomer having a first crosslinkable group.
Polyrotaxane having two or more second crosslinkable groups and
A paint for vehicle interior members, which comprises a curing agent having two or more functional groups capable of reacting with at least one of the first crosslinkable group and the second crosslinkable group .
A paint for vehicle interior members, wherein the ratio of the mass of the fluorine-containing polymer to the mass of the polyrotaxane is 2.0 to 90 . The coating material according to claim 1, wherein the fluorine-containing polymer has a glass transition temperature of 50 ° C. or higher. The fluoropolymer further comprises a unit based on a monomer having an alkyl group having a tertiary carbon atom having 3 to 9 carbon atoms or a cycloalkyl group having 4 to 10 carbon atoms in a side chain, and the unit thereof. The coating material according to claim 1 or 2, wherein the content is 10 to 45 mol% with respect to all the units contained in the fluoropolymer. Any one of claims 1 to 3, wherein the content of the unit based on the monomer having the first crosslinkable group is 1 to 40 mol% with respect to all the units contained in the fluorine-containing polymer. The paint described in. The coating material according to any one of claims 1 to 4, wherein the first crosslinkable group is a hydroxy group and the hydroxyl value of the fluorine-containing polymer is 1 to 150 mgKOH / g. The coating material according to any one of claims 1 to 5 , wherein the glass transition temperature of the polyrotaxane is 0 ° C. or lower. Claims 1 to 6 wherein the polyrotaxane is a polyrotaxane having cyclodextrin as a cyclic molecule and polyethylene glycol having both ends sealed with a blocking group as a shaft molecule, or a cyclic ester-modified product or a cyclic ether-modified product of the polyrotaxane. The paint according to any one of the above items. The coating material according to any one of claims 1 to 7 , wherein the second crosslinkable group is a hydroxy group or a carboxy group. The coating material according to claim 8 , wherein the second crosslinkable group is a hydroxy group, and the hydroxyl value of the polyrotaxane is 200 mgKOH / g or less. The coating material according to any one of claims 1 to 9 , wherein the weight average molecular weight of the shaft molecule of the polyrotaxane is 1,000 or more. The coating material according to any one of claims 1 to 10 , wherein the content of the polyrotaxane is 0.1 to 30% by mass with respect to the total amount of the fluorine-containing polymer, the polyrotaxane and the curing agent. The coating material according to any one of claims 1 to 11 , wherein both the first crosslinkable group and the second crosslinkable group are hydroxy groups, and the curing agent is an isocyanate-based curing agent. A vehicle interior member comprising a vehicle interior base material and a cured film formed from the paint according to any one of claims 1 to 12 arranged on the vehicle interior base material. A method for manufacturing a vehicle interior member, wherein the paint according to any one of claims 1 to 12 is applied onto a vehicle interior base material to form a coating film, and the coating film is cured to form a cured film. ..