JP4420887B2 - Cured solvent-based stone guard coat formed on the car body - Google Patents

Description

The present invention relates to a curable solvent-based stone guard coat formed on the vehicle body.

When resin molded products such as polycarbonate and acrylic do not satisfy the required levels of physical properties such as hardness, weather resistance, stain resistance, and solvent resistance, surface treatment is performed to supplement these physical properties. May be applied.
For such surface treatments, curable paints such as room temperature drying paints and two-component urethane paints are usually used, but the surface treatment films with such paints are easily scratched and scratched. This is easily noticeable.

In addition, in order to improve the design as a product, various parts may be subjected to metal mirror surface treatment such as plating, vapor deposition, and sputtering. Scratches are easily attached, and the attached scratches are easily noticeable.
For this reason, such a mirror-finished film is usually further subjected to a surface treatment with a paint as described above. However, the paint-treated film is also easily damaged as described above, and the attached scratch is conspicuous. There is a drawback that it is easy.

Also, in recent years, automobile body painting has been increasingly oriented toward high durability so that the appearance of a new car can be maintained over a long period of time. There is a need for scratch resistance and chipping resistance that are not attached.
In order to obtain such chipping resistance, a melamine curable soft paint, a two-component acrylic urethane soft paint, and a polyolefin soft paint have been added to a part of the laminated structure such as the hood tip or undercoat. and it is known to apply a strike over emissions guard coat (SGC) (see Patent Document 1.).
JP 59-75954 A

However, the undercoat and strike over emissions guard coat thicker film thickness, not only increasing the cost, is not very good coating appearance under the influence of the resin which is applied in order to improve the chipping resistance.
In addition, since anti-chipping coating using polyolefin resin requires many steps, not only does the coating process need to be lengthened, but also costs are increased.
Therefore, development of a coating film that can improve chipping resistance with a thin film is desired.

The present invention was made in view of the above problems in the non-exposed surface coating, such as the conventional undercoat and strike over emissions guard coat, it is an object of excellent scratch resistance Another object of the present invention is to provide a curable solvent-based stone guard coat formed on a vehicle body having a chipping resistance.

As a result of intensive studies to achieve the above object, the present inventors have achieved the above object by using a lipophilic polyrotaxane in which a linear molecule or a cyclic molecule has a predetermined hydrophobic modification group. The present inventors have found that this can be done and have completed the present invention.

That is, the curable solvent-based stone guard coat formed on the vehicle body of the present invention contains a lipophilic polyrotaxane and at least one selected from the group consisting of acrylic paints, melamine paints, and urethane paints. Solidified curable solvent-based stone guard coat paint,
The lipophilic polyrotaxane has a cyclic molecule , a linear molecule that includes the cyclic molecule in a skewered manner, and a blocking group that is disposed at both ends of the linear molecule and prevents the cyclic molecule from detaching. and, a Turkey which have a a modifying group according caprolactone via a straight-chain molecule and / or cyclic molecules -C ₃ H ₆ -O- group _{(-CO (CH 2) 5 OH} ) group Features.

Further, the preferred form of the curable solvent-based stone guard coat formed on the vehicle body of the present invention is the maximum inclusion amount in which the inclusion amount of the cyclic molecule is the maximum amount that the linear molecule includes the cyclic molecule. If 1 is 1, it is 0.06 to 0.61.

According to the present invention, since a linear molecule or a cyclic molecule uses a lipophilic polyrotaxane having a predetermined hydrophobic modification group, etc., the curing formed on the vehicle body having excellent scratch resistance and chipping resistance. A type solvent-based stone guard coat can be provided.

Hereinafter, the curable solvent type stone guard coat formed on the vehicle body of the present invention will be described in detail. In the present specification, “%” represents mass percentage unless otherwise specified.

As described above, the curable solvent-based stone guard coat formed on the vehicle body of the present invention includes at least one selected from the group consisting of an oleophilic polyrotaxane , an acrylic paint, a melamine paint, and a urethane paint. A curable solvent-based stone guard coat paint containing
This lipophilic polyrotaxane has a cyclic molecule and a linear molecule having blocking groups at both ends. Further, the linear molecule includes the cyclic molecule by penetrating the opening of the cyclic molecule in a skewered manner, and further the elimination of the cyclic molecule in which the blocking groups arranged at both ends are included. Is preventing.
In addition, either one or both of the linear molecule and the cyclic molecule constituting the polyrotaxane have a hydrophobic modifying group.

FIG. 1 is a schematic diagram conceptually showing a hydrophobic modified polyrotaxane.
In this figure, this hydrophobic modified polyrotaxane 5 has a linear molecule 6, a cyclodextrin 7 which is a cyclic molecule, and blocking groups 8 arranged at both ends of the linear molecule 6. The molecule 6 penetrates through the opening of the cyclic molecule 7 and includes the cyclic molecule 7.
And the cyclodextrin 7 has the hydrophobic modification group 7a.

By using such a lipophilic polyrotaxane, that obtained miscible in organic solvents. In addition, when applied to paint, the durability of the product is improved. In other words, scratch resistance and chipping resistance can be improved. Further, it is effective because other adverse performances are hardly adversely affected.

Here, the linear molecule may be substantially linear, and has a branched chain as long as the cyclic molecule that is a rotor can rotate and can be included so as to exert a pulley effect. Also good.
Moreover, although it is influenced also by the magnitude | size of a cyclic molecule, the length is not specifically limited as long as a cyclic molecule can exhibit a pulley effect.

In the oleophilic polyrotaxane used for the curable solvent-based stone guard coat formed on the vehicle body of the present invention, either one or both of the linear molecule and the cyclic molecule have a hydrophobic modifying group. Soluble in solvent.
Such lipophilic expression provides a reaction field called an organic solvent, typically a cross-linking field, to a polyrotaxane that has been conventionally poorly soluble or insoluble in an aqueous solvent or an organic solvent. That is, the lipophilic polyrotaxane used for the curable solvent-based stone guard coat formed on the vehicle body of the present invention has improved reactivity that can be easily cross-linked with other polymers and modified with a modifying group in the presence of an organic solvent. Is.

The hydrophobic modification group has a hydrophobic group or a hydrophobic group and a hydrophilic group, and may be hydrophobic as a whole.
Examples of the hydrophobic group include an alkyl group, a benzyl group (benzene ring) and a benzene derivative-containing group, an acyl group, a silyl group, a trityl group, a nitrate ester group, and a tosyl group.
Examples of the hydrophilic group include a carboxyl group, a sulfonic acid group, a sulfate ester group, a phosphate ester group, an amino group (primary to tertiary), a quaternary ammonium base, and a hydroxyalkyl group.

The linear molecule is not particularly limited, and examples thereof include polyesters such as polyalkyls and polycaprolactone, polyethers, polyamides, polyacryls, and linear molecules having a benzene ring. it can.
Specific examples include polyethylene glycol, polyisoprene, polybutadiene, polypropylene glycol, polytetrahydrofuran, polydimethylsiloxane, polyethylene, and polypropylene.
Among these linear molecules, polyethylene glycol and polycaprolactone are particularly preferable, and polycaprolactone is preferably used from the viewpoint of solubility in an organic solvent.

The molecular weight of the linear molecule is desirably 1,000 to 100,000, preferably 30,000 to 80,000, and more preferably 60,000 to 80,000.
When the molecular weight is less than 1,000, the pulley effect is lowered, the elongation of the coating film is lowered, and the scratch resistance and chipping resistance may be lowered. If it exceeds 100,000, the compatibility with other resins may be reduced, and the adhesion to the substrate may be reduced.

In addition, as said linear molecule, what has a reactive group in the both ends is preferable, and this enables it to react with the said blocking group easily.
Such a reactive group can be appropriately changed according to the type of blocking group employed, and examples thereof include a hydroxyl group, an amino group, a carboxyl group, and a thiol group.

The cyclic molecule is not particularly limited as long as it is included in the linear molecule as described above and exhibits a pulley effect, and various cyclic substances can be exemplified.
Many cyclic molecules have a hydroxyl group.
In addition, the cyclic molecule is sufficient if it is substantially cyclic, and includes those that are not completely closed, such as “C” shape.

The cyclic molecule preferably has a reactive group, which facilitates crosslinking with another polymer and bonding with a modifying group.
Such reactive groups can be appropriately changed, and examples thereof include a hydroxyl group, an amino group, a carboxyl group, a thiol group, and an aldehyde group.
The reactive group is preferably a group that does not react with the blocking group when a blocking group described later is formed (blocking reaction).

  Furthermore, specific examples of the cyclic molecule include various cyclodextrins such as α-cyclodextrin (glucose number: 6), β-cyclodextrin (glucose number: 7), γ-cyclodextrin (glucose number: 8), dimethylcyclodextrin, glucosylcyclodextrin and derivatives or modified products thereof, and crown ethers, benzocrowns, dibenzocrowns, dicyclohexanocrowns and derivatives or modified products thereof.

The above-mentioned cyclic molecules such as cyclodextrin can be used alone or in combination of two or more.
In particular, α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin are preferable, and α-cyclodextrin is preferable from the viewpoint of inclusion.

Moreover, if a hydrophobic modifying group is introduced into the hydroxyl group of cyclodextrin, the solvent solubility of the lipophilic polyrotaxane can be further improved.
At this time, the degree of modification by the hydrophobic modifying group is preferably 0.02 or more, more preferably 0.04 or more, and 0 when the maximum number of cyclodextrin hydroxyl groups that can be modified is 1. More preferably, it is 0.06 or more.
If it is less than 0.02, the solubility in an organic solvent will not be sufficient, and insoluble bumps (protrusions derived from adhesion of foreign matter, etc.) may be generated.

Here, the maximum number that the hydroxyl groups of cyclodextrin can be modified is, in other words, the total number of hydroxyl groups that cyclodextrin had before modification. In other words, the degree of modification is the ratio of the number of modified hydroxyl groups to the total number of hydroxyl groups.
Although at least one hydrophobic group may be used, it is desirable to have one hydrophobic group for each cyclodextrin ring.
Further, by introducing a hydrophobic group having a functional group, the reactivity with other polymers can be improved.

  As a method for introducing the hydrophobic modifying group, for example, cyclodextrin is used as a cyclic molecule of polyrotaxane, the hydroxy group of the cyclodextrin is hydroxypropylated using propylene oxide, and then ε-caprolactone is added, followed by 2-ethyl A method of adding tin hexanoate can be employed. The degree of modification can be arbitrarily controlled by changing the amount of ε-caprolactone added at this time.

In the lipophilic polyrotaxane used for the curable solvent-based stone guard coat formed on the vehicle body of the present invention, the number of inclusion molecules included in the linear molecule (inclusion amount) is 1 as the maximum inclusion amount. Then, 0.06-0.61 is preferable, 0.11-0.48 is still more preferable, 0.24-0.41 is still more preferable.
If it is less than 0.06, the elongation effect of the coating film may decrease due to a decrease in the pulley effect. If it exceeds 0.61, the cyclic molecules may be arranged too densely and the mobility of the cyclic molecules may decrease, the elongation of the coating film may decrease, and the scratch resistance and chipping resistance may decrease. .

Further, the amount of inclusion of the cyclic molecule can be controlled as follows.
For example, to DMF (dimethylformamide), a BOP reagent (benzotriazol-1-yl-oxy-tris (dimethylamino) phosphonium hexafluorophosphate), HOBt, adamantaneamine, and diisopropylethylamine are added in this order. To do. On the other hand, a solution is obtained in which a clathrate complex in which a cyclic molecule is skewered into a linear molecule is dispersed in a DMF / DMSO (dimethyl sulfoxide) mixed solvent. By mixing these two and changing the mixing ratio of DMF / DMSO at this time, the inclusion amount of the cyclic molecule can be arbitrarily controlled. In addition, the higher the DMF / DMSO ratio, the greater the amount of inclusion of the cyclic molecule.

The blocking group may be any group as long as it is arranged at both ends of the linear molecule as described above and can maintain a state where the cyclic molecule is penetrated by the linear molecule in a skewered manner. .
Examples of such a group include a group having “bulkiness” or a group having “ionicity”. Further, the “group” here means various groups including a molecular group and a polymer group.

Examples of the “bulky” group include a spherical group and a side wall-shaped group.
In addition, the ionicity of the group having “ionicity” and the ionicity of the cyclic molecule interact with each other, for example, by repelling each other, so that the cyclic molecule is skewed into a linear molecule. Can be held.

  Specific examples of such blocking groups include dinitrophenyl groups such as 2,4-dinitrophenyl group and 3,5-dinitrophenyl group, cyclodextrin groups, adamantane groups, trityl groups, fluorescein groups, and the like. Examples include pyrenes and derivatives or modified products thereof.

As described above, the lipophilic polyrotaxane used in the curable solvent-based stone guard coat is composed of a lipophilic polyrotaxane having a hydrophobic modifying group, and the lipophilic polyrotaxane can be typically produced as follows. .
(1) mixing a cyclic molecule with a linear molecule, penetrating through the opening of the cyclic molecule with a linear molecule in a skewered manner, and including the cyclic molecule in the linear molecule; (2) obtaining A step of preparing both the ends of the obtained pseudopolyrotaxane (both ends of the linear molecule) with a blocking group so that the cyclic molecule is not detached from the skewered state, and (3) a cyclic molecule of the obtained polyrotaxane. It is obtained by treating in the step of modifying the hydroxyl group possessed by a hydrophobic modifying group.
In the step (1), a lipophilic polyrotaxane can also be obtained by using a cyclic molecule in which a hydroxyl group of the cyclic molecule is previously modified with a hydrophobic modifying group. 3) The process can be omitted.

By this production method, a lipophilic polyrotaxane used for a curable solvent-based stone guard coat formed on a vehicle body having excellent solubility in an organic solvent as described above can be obtained.
The organic solvent is not particularly limited, but alcohols such as isopropyl alcohol and butyl alcohol, esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, diethyl ether and dioxane, etc. Ethers, hydrocarbon solvents such as toluene and xylene, and the like. The lipophilic polyrotaxane exhibits good solubility even in a solvent in which two or more of these are mixed.

In the present invention, the lipophilic polyrotaxane may be crosslinked as long as it is soluble in an organic solvent, and the lipophilic crosslinked polyrotaxane may be used instead of the non-crosslinked lipophilic polyrotaxane or this. It can be used as a mixture.
Examples of such a lipophilic crosslinked polyrotaxane include a lipophilic polyrotaxane crosslinked with a polymer having a relatively low molecular weight, typically a polymer having a molecular weight of about several thousand.

Moreover, in this invention, it is desirable from a viewpoint that all or one part of a hydrophobic modification group has a functional group from the viewpoint of improving the reactivity with another polymer.
Such a functional group is preferably sterically structured outside the cyclodextrin, and can be easily reacted with the functional group when bonded or crosslinked with the polymer.

Such a functional group can be appropriately changed according to, for example, the type of solvent used when a crosslinking agent is not used. On the other hand, when using a crosslinking agent, it can change suitably according to the kind of the crosslinking agent to be used.
Furthermore, in the present invention, specific examples of the functional group may include, for example, a hydroxyl group, a carboxyl group, an amino group, an epoxy group, an isocyanate group, a thiol group, and an aldehyde group, but are not limited thereto. .

And in a hydrophobic modification polyrotaxane, the above-mentioned functional group may have the 1 type individually or in combination of 2 or more types.
Such functional groups are particularly residues of compounds bonded to the hydroxyl group of cyclodextrin, and those having a hydroxyl group, a carboxyl group, an amino group, an epoxy group, or an isocyanate group are good, and there are various reactions. From the viewpoint of properties, a hydroxyl group is preferred.
Examples of the compound that forms such a functional group include propylene oxide, but are not limited thereto.
For example, if the effect of improving the solubility of the hydrophobic modified polyrotaxane in an organic solvent is not significantly reduced, the compound forming the functional group may be a polymer. From the viewpoint of solubility, for example, the molecular weight is several thousand. It is desirable that the degree.
The above functional group is preferably a group that reacts under reaction conditions in which the above-mentioned blocking group is not eliminated.

About curable solvent-based stone guard coat formed on the vehicle body of the present invention will be described in detail.
Hardening type solvent-based stone guard coat paint is made by using the oleophilic polyrotaxane used in the curable solvent-based stone guard coat described above. The curable solvent-based stone guard coat formed on the vehicle body of the present invention is formed by solidifying the curable solvent-based stone guard coat paint.

Thus, when forming a coating film, the hydrophobic modifying group and other functional groups of the lipophilic polyrotaxane used in the curable solvent-based stone guard coat react with the coating film forming component to form a crosslinked polyrotaxane. It will be excellent in scratch resistance and chipping resistance.

In general, the crosslinked polyrotaxane refers to a crosslinked polyrotaxane and another polymer, but at the time of coating film formation, the polyrotaxane constituting the lipophilic polyrotaxane used for the curable solvent-based stone guard coat described above is a coating film. It is formed by crosslinking with a forming component (polymer or the like). This coating film-forming component is bonded to the polyrotaxane via the polyrotaxane cyclic molecule.

Hereinafter, the crosslinked polyrotaxane will be described.
FIG. 2 conceptually shows the crosslinked polyrotaxane.
In this figure, the crosslinked polyrotaxane 1 has a polymer 3 and the lipophilic polyrotaxane 5. And this polyrotaxane 5 is couple | bonded with the polymer 3 and the polymer 3 'by the crosslinking point 9 through the cyclic molecule 7. FIG.

When a deformation stress in the direction of arrow XX ′ in FIG. 2A is applied to the crosslinked polyrotaxane 1 having such a configuration, the crosslinked polyrotaxane 1 is deformed as shown in FIG. 2B. This stress can be absorbed.
That is, as shown in FIG. 2B, the cyclic molecule 7 can move along the linear molecule 6 due to the pulley effect, so that the stress can be absorbed therein.

Thus, the crosslinked polyrotaxane has a pulley effect as shown in the figure, and has excellent stretchability, viscoelasticity, and mechanical strength as compared with a conventional gel-like material.
Further, the lipophilic polyrotaxane, which is a precursor of the crosslinked polyrotaxane, has improved solubility in an organic solvent as described above, and is easily crosslinked in an organic solvent.

Therefore, the crosslinked polyrotaxane can be easily obtained under conditions where an organic solvent is present, and can be easily produced by crosslinking a lipophilic polyrotaxane and an organic solvent-soluble coating film-forming component.
Therefore, the oleophilic polyrotaxane used in the curable solvent-based stone guard coat of the present invention has an expanded range of applications, for example, paints and adhesives using a coating film polymer soluble in organic solvents, particularly car wash resistance. It can also be applied to paints for automobiles, resin base materials and adhesives, and paints and resin base materials for home appliances that require scratch resistance, chipping resistance, impact resistance and weather resistance. An excellent pulley effect can be exhibited even in applications.

From another point of view, the crosslinked polyrotaxane is a composite of the coating film-forming component and the polyrotaxane without impairing the physical properties of the coating film-forming component that is an object of crosslinking of the lipophilic polyrotaxane.
Therefore, according to the method for forming a crosslinked polyrotaxane described below, a material having both the physical properties of the coating film forming component and the lipophilic polyrotaxane itself can be obtained. It is possible to obtain a coating film having a mechanical strength of
Note that the crosslinked polyrotaxane is soluble in an organic solvent if the crosslinking target is hydrophobic and the molecular weight is not so large, for example, if the molecular weight is up to about several thousand.

Here, a method for forming a crosslinked polyrotaxane will be described.
Crosslinked polyrotaxane is typically, (a) a lipophilic Porirotakisa emissions used in the curable solvent-based stone guard coat mixed with other coating film forming components, (b) physical at least part of the coating film forming components (C) at least a part of the coating film-forming component and a lipophilic polyrotaxane are bonded via a cyclic molecule (curing reaction).
In addition, since lipophilic polyrotaxane is soluble in the organic solvent, the (a) process-(c) process can be performed smoothly in an organic solvent. Moreover, these processes can be performed more smoothly by using a curing agent.

  In the steps (b) and (c), it is preferable to perform chemical crosslinking. For example, the hydroxyl group of the lipophilic polyrotaxane as described above and a melamine resin, which is an example of a paint forming component, are urethane-bonded. Is repeatedly formed to obtain a crosslinked polyrotaxane. Moreover, you may implement the (b) process and the (c) process substantially simultaneously.

  The mixing step (a) depends on the coating film forming component to be used, but can be performed without a solvent or in a solvent. Further, the solvent can be removed by heat treatment or the like when forming the coating film.

Moreover, it is preferable that 1-90% of the said curable solvent type non-exposed surface coating material is contained by mass conversion with respect to a coating-film formation component (resin solid content etc.). More preferably, it is 10 to 50%, and particularly preferably 20 to 40%.
If it is less than 1%, the pulley effect is lowered, the coating film elongation rate is lowered, and scratch resistance and chipping resistance may not be obtained. If it exceeds 90%, the adhesion to the substrate may be lowered.

Furthermore, the coating material for the curable solvent-based stone guard coat includes a lipophilic polyrotaxane used for the curable solvent-based stone guard coat , a resin component, a curing agent, an additive, a pigment, a brightening agent, or a solvent, and any combination thereof. It is preferable to mix these.

The resin component is not particularly limited, but the main chain or side chain is a hydroxyl group, amino group, carboxyl group, epoxy group, vinyl group, thiol group or photocrosslinking group, and any combination thereof. Those having a group are preferred.
Examples of the photocrosslinking group include cinnamic acid, coumarin, chalcone, anthracene, styrylpyridine, styrylpyridinium salt, and styrylquinoline salt.

Two or more kinds of resin components may be mixed and used. In this case, it is preferable that at least one kind of resin component is bonded to the polyrotaxane via a cyclic molecule.
Further, the resin component may be a homopolymer or a copolymer. In the case of a copolymer, it may be composed of two or more monomers, and may be a block copolymer, an alternating copolymer, a random copolymer or a graft copolymer.

Specific examples include polyvinyl alcohol, polyvinyl pyrrolidone, poly (meth) acrylic acid, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and other cellulose resins, polyacrylamide, polyethylene oxide, polyethylene glycol, polypropylene glycol, polyvinyl acetal resins, Polyolefin resins such as polyvinyl methyl ether, polyamine, polyethyleneimine, casein, gelatin, starch and copolymers thereof, copolymer resins with polyethylene, polypropylene and other olefinic monomers, polyester resins, polyvinyl chloride resins , Polystyrene resins such as polystyrene and acrylonitrile-styrene copolymer resin, polymethyl methacrylate and (meth) acrylic Acrylic resins such as acid ester copolymers, acrylonitrile-methyl acrylate copolymers, polycarbonate resins, polyurethane resins, vinyl chloride-vinyl acetate copolymer resins, polyvinyl butyral resins and derivatives or modified products thereof, polyisobutylene, polytetrahydrofuran , Polyaniline, acrylonitrile-butadiene-styrene copolymer (ABS resin), polyamides such as nylon (registered trademark), polyimides, polydienes such as polyisoprene and polybutadiene, polysiloxanes such as polydimethylsiloxane, polysulfones, List polyimines, polyacetic anhydrides, polyureas, polysulfides, polyphosphazenes, polyketones, polyphenylenes, polyhaloolefins, and their derivatives It can be.
As the derivatives, those having the above-mentioned hydroxyl group, amino group, carboxyl group, epoxy group, vinyl group, thiol group, photocrosslinking group, and groups related to these combinations are preferable.

Specific examples of the curing agent include melamine resin, polyisocyanate compound, blocked isocyanate compound, cyanuric chloride, trimesoyl chloride, terephthaloyl chloride, epichlorohydrin, dibromobenzene, glutaraldehyde, phenylene diisocyanate, diisocyanate trilein. , Divinylsulfone, 1,1′-carbonyldiimidazole or alkoxysilanes. In the present invention, these can be used alone or in combination of two or more.
Moreover, the said hardening | curing agent can use the molecular weight below 2000, Preferably it is less than 1000, More preferably, it is less than 600, More preferably, it is less than 400.

  Specific examples of the additive include a dispersant, an ultraviolet absorber, a light stabilizer, a surface conditioner, and a crack inhibitor.

  Specific examples of the pigment include organic color pigments such as azo pigments, phthalocyanine pigments, and perylene pigments, and inorganic color pigments such as carbon black, titanium dioxide, and bengara.

  Specific examples of the brightening agent include aluminum pigments and mica pigments.

Specific examples of the solvent include esters such as ethyl acetate, butyl acetate and isobutyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ethers such as diethyl ether and dioxane, toluene and xylene, Hydrocarbon solvents such as Solvesso or long-chain alcohols with high hydrophobicity can be used.
Two or more of these may be mixed as appropriate. Moreover, even if some aqueous solvents, such as water and a butyl cellosolve acetate, are contained, it should just be considered as an organic solvent as a whole.

  In addition, when mixing the lipophilic polyrotaxane with the various coating materials described above, the polyrotaxane in a state imparted with lipophilicity may be blended as it is, but the lipophilic polyrotaxane is dissolved in a solvent such as an organic solvent in advance. It is desirable to mix in a diluted state. Such a polyrotaxane solution may be prepared at the time of producing the paint or may be prepared prior to the production of the paint.

The curable solvent-based stone guard coat paint used in the present invention may be a transparent clear paint, a turbid clear paint, a matte paint, or a top coat. Further, as the top coat, a base coat paint or an enamel paint can be used.
In order to make the curable solvent-based stone guard coat paint used in the present invention a turbid clear paint, an organic pigment, an inorganic pigment, or a dye may be added in addition to the above components, and a matting agent such as silica or resin beads. By adding, a matte clear paint can be obtained.

The stone guard coat may be formed from a general-curable solvent-based stone guard coat paint is typically a lipophilic fluid, acrylic paints, melamine paints, stone such as urethane-based paint Guard coat paints can be used alone or in combination.
The lipophilic liquid may be a one-pack type, a two-pack type (for example, urethane resin paint) or the like, or a lacquer or photo-curing resin.

The film thickness of the stone guard coat is not particularly limited, but is preferably about 20 to 40 μm.

It will now be described in detail the product-layer coating film.
Product layer coating is the coating object, comprising sequentially forming a stone guard coat formed by using the base coating film with the above-mentioned curable solvent-based stone guard coat paint.

This improves the scratch resistance and chipping resistance of the laminated coating film. In addition, by including a predetermined resin or the like in the stone guard coat , a cross-linked structure with a lipophilic polyrotaxane can be formed at the interface with the base coat film, and the scratch resistance can be further improved.

Examples of the article to be coated typically include various metal materials such as iron, aluminum and copper, various organic materials such as polypropylene and polycarbonate, and various inorganic materials such as quartz and ceramics (calcium carbide, etc.).
In addition, as a method of coating these with a curable solvent-based stone guard coat paint, a publicly known method can be employed. For example, a brush coating method, a spraying method, an electrostatic coating method, an electrodeposition coating method, a powder coating, and a sputtering method can be used.
Further, the curable solvent-based stone guard coat paint can be typically formed into a coating film by heat drying (baking) treatment.
The curable solvent-based stone guard coat coating can be applied to the whole or a part of the object to be coated.

In the product layered coating film under the base coating film, it is preferable to further form an undercoating film. In this case, a cross-linked structure with a lipophilic polyrotaxane can be formed at the interface with the undercoat film, which is effective.

An example (schematic cross section) of the curable solvent-based stone guard coat formed on the vehicle body of the present invention described above is shown in FIG.
This coating film is composed of a stone guard coat 11 formed on an object (for example, an ABS resin base material) 10.

  EXAMPLES Hereinafter, although a specific Example is given and this invention is demonstrated in detail, this invention is not limited by a following example.

Example 1
1. Synthesis of Modified Polyrotaxane 10 mL of ε-caprolactone dried with molecular sieves was added to 500 mg of hydroxypropylated polyrotaxane having a hydroxyl group modified with a hydroxypropyl group, and the mixture was allowed to permeate by stirring at room temperature for 30 minutes. Thereafter, 0.2 mL of tin 2-ethylhexanoate was added and reacted at 100 ° C. for 1 to 8 hours.
After completion of the reaction, the sample was dissolved in 50 mL of toluene, dropped into 450 mL of hexane which was stirred, precipitated and collected.

2. Preparation of Curing Type Solvent-Based Stone Guard Coat The obtained polyrotaxane was dissolved in toluene so as to be 10%.
Next, the dissolved polyrotaxane was added to an acrylic / melamine curable enamel paint (Nippon Yushi Co., Ltd., Bell Coat No. 6200GN1) with stirring.

3. Formation of the coating film The ABS resin (thickness 3 mm, 70 mm × 150 mm) manufactured by Mitsubishi Chemical Co., Ltd. was coated with the obtained curable solvent-based stone guard coat paint so that the dry film thickness was 20 μm. Baking for 30 minutes gave the curable solvent-based stone guard coat of this example.

(Examples 2-11, Comparative Examples 1-3)
A coating film was formed by repeating the same operation as in Example 1 except that the specifications shown in Table 1 were used.

(Evaluation of coating film performance)
The scratch resistance, adhesion and reactivity of the curable solvent-based stone guard coats obtained in the above Examples and Comparative Examples were evaluated based on the following criteria. The results are also shown in Table 1.

(1) Scratch resistance Dustnel (friction cloth) was attached to a slider of an abrasion tester with a double-sided tape, and was reciprocated 50 times under a load of 0.22 g / cm ² to evaluate the presence or absence of scratches.
○: Almost no damage △: There is a slight scratch ×: There are many scratches that stand out

(2) Adhesiveness 100 cross-cuts were produced and a peel test was performed with a cellophane tape. After the peel test, the number of grids remaining as a coating film was evaluated.
○: 100/100
Δ: 90/100 or more ×: less than 90/100

(3) Reactivity The polyrotaxane obtained in Step 1 and hexamethylene diisocyanate were mixed in an equivalent ratio, and baked at 140 ° C. for 30 minutes to dry. Judging by the presence or absence of urethane bonds, the infrared absorption spectrum of the coating film was used.
○: Urethane bond present ×: No urethane bond present

As is apparent from the results in Table 1, the curable solvent-based stone guard coats of preferred Examples 1 to 8 of the present invention have improved scratch resistance, chipping resistance and reactivity based on the pulley effect of the polyrotaxane. In addition, good adhesion was confirmed.
In addition, in Examples 9 to 11, although the molecular weight of the linear molecule and the content of the lipophilic polyrotaxane deviated from the preferred range, a tendency to be somewhat inferior in adhesion, reactivity, and scratch resistance was also observed. It is judged to be superior to Comparative Examples 1 to 3.

It is a schematic diagram which shows notionally hydrophobic modification polyrotaxane. 1 is a schematic diagram conceptually showing a crosslinked polyrotaxane. It is a schematic sectional drawing which shows an example of the coating film of this invention.

Explanation of symbols

1 Crosslinked polyrotaxane 3, 3 ′ polymer 5 Hydrophobic modified polyrotaxane 6 Linear molecule 7 Cyclic molecule (cyclodextrin)
7a Hydrophobic modifying group 8 Blocking group 9 Cross-linking point 10 ABS resin base material 11 Stone guard coat

Claims (6)

A curable solvent-based stone guard coat formed on the vehicle body,
Solidifying a curable solvent-based stone guard coat paint containing a lipophilic polyrotaxane and at least one selected from the group consisting of acrylic paint, melamine paint and urethane paint,
The lipophilic polyrotaxane has a cyclic molecule, a linear molecule that includes the cyclic molecule in a skewered manner, and a blocking group that is disposed at both ends of the linear molecule and prevents the cyclic molecule from detaching. And the linear molecule and / or the cyclic molecule has a (—CO (CH ₂ ) ₅ OH) group which is a modified group by caprolactone via a —C ₃ H ₆ —O— group. A curable solvent-based stone guard coat formed on the car body. The cyclic molecule has a hydroxyl group, and all or part of the hydroxyl group is modified with a (—CO (CH ₂ ) ₅ OH) group which is a modified group by caprolactone via a —C ₃ H ₆ —O— group. The curable solvent-based stone guard coat formed on the vehicle body according to claim 1.   The inclusion amount of the cyclic molecule is 0.06 to 0.61, where 1 is the maximum inclusion amount, which is the maximum amount that the linear molecule includes the cyclic molecule. Or a curable solvent-based stone guard coat formed on the vehicle body according to 2;   The curable solvent-based stone guard coat formed on the vehicle body according to any one of claims 1 to 3, wherein the linear molecule is polyethylene glycol and / or polycaprolactone. The lipophilic polyrotaxane curable solvent system which is formed in the vehicle body according to any one of claims 1-4, characterized in that contained 1% to 90% by mass in terms of the coating film-forming component Stone guard coat. The curable solvent-based stone guard coat coating material is a mixture of at least one selected from the group consisting of additives, pigments, and brightening agents, a solvent, a resin component, and a curing agent. A curable solvent-based stone guard coat formed on the vehicle body according to any one of claims 1 to 5 .

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