JP5564592B1 - Resin composition and coated body using the same - Google Patents

Abstract

A resin composition capable of forming a coating film excellent in adhesion to a plastic substrate, water resistance and chemical resistance is provided.
An acrylic-modified cellulose derivative (A) obtained by graft polymerization or simply bonding an acrylic component to a cellulose derivative, having a specific acrylic component grafting amount or bonding amount, a weight average molecular weight, and a glass transition temperature. An acrylic modified cellulose derivative (A) and a mixture of a cellulose derivative (B) other than the acrylic modified cellulose derivative and an acrylic resin (C), the composition in the mixture, the weight average molecular weight of the cellulose derivative (B) And at least one of a mixture having a glass transition temperature of the acrylic resin (C) within a specific range as a resin component, and the resin component has a total acid value and hydroxyl value of 7 to 100 mgKOH / g It is a resin composition characterized by these.
[Selection figure] None

Description

  The present invention relates to a resin composition and a coated body using the resin composition, and in particular, can form a coating film excellent in adhesion to a plastic substrate and excellent in water resistance and chemical resistance. The present invention relates to a resin composition.

  A plastic molded article is a molded article of a polymer material having plasticity, and is used for mobile phones, home appliances, office automation equipment, etc. The surface of the plastic molded article is decorated or given a function. May have been painted to do. Therefore, paints for coating plastic (paints for plastics) are decorated, and depending on the application of plastic molded products, the coating film has abrasion resistance, anti-fading resistance, sebum resistance, high glossiness, It may be required to provide functions such as high weather resistance and electrical insulation.

  In addition, for plastic molded products that contact human skin and hands for a long time (for example, mobile phone exterior parts and automobile interior parts), sweat resistance, lactic acid resistance, hand cream resistance and sun protection cream It is also required to have excellent chemical resistance such as property.

  In response to such a demand, Japanese Patent Application Laid-Open No. 2005-290136 (Patent Document 1) discloses a methacrylic resin composition obtained by polymerizing a methacrylic ester polymer in the presence of acrylic ester cross-linked elastic particles. The imidized methacrylic resin composition is modified by treating the product with an imidizing agent, and the imidized methacrylic resin composition has chemical resistance, heat resistance, thermal stability and hardness. We report that it is excellent and has improved folding resistance and folding whitening resistance. However, the imidized methacrylic resin composition described in Patent Document 1 has not been sufficiently resistant to sunscreen.

  On the other hand, Japanese Patent Application Laid-Open No. 2008-265062 (Patent Document 2) discloses an acrylic resin film for thermoforming having an acrylic resin film and a cured resin layer having a specific thickness as an outermost layer and having a 60 ° surface glossiness of 100% or more. It is reported that this laminate is excellent in chemical resistance. However, since the laminate described in Patent Document 2 is manufactured by an in-mold molding method or an insert molding method, heating at a temperature of 70 ° C. or more is required when forming the cured resin layer, and a large amount of thermal energy is required. .

  Japanese Patent Laid-Open No. 2010-18720 (Patent Document 3) discloses that a (meth) acrylic resin obtained by polymerizing a specific monomer mixture in the presence of acrylic ester-based crosslinked elastic particles is an ammonia-based compound. It describes an acrylic film for automobiles obtained by imidization with an automotive acrylic film having excellent chemical resistance, surface hardness and bending whitening resistance, and the automotive acrylic film is laminated on metal, plastic, etc. It can also be used. However, the acrylic film for automobiles described in Patent Document 3 needs to be heated to a temperature exceeding 100 ° C. during film formation, and requires a lot of heat energy.

  Incidentally, JP-A-9-235505 (Patent Document 4) describes a coating composition containing cellulose acetate butyrate, nitrocellulose, and an acrylic resin in a specific ratio. However, the coating composition described in Patent Document 4 is a paint for repairing automobile bodies, and coating on plastic is not assumed at all. Actually, even when this coating composition is applied to a plastic substrate, it is difficult to obtain a coating film excellent in all of adhesion to the plastic substrate, water resistance and chemical resistance.

JP 2005-290136 A JP 2008-265062 A JP 2010-18720 A JP-A-9-235505

  Therefore, an object of the present invention is to provide a resin composition capable of solving the above-mentioned problems of the prior art and forming a coating film excellent in adhesion to a plastic substrate, water resistance and chemical resistance. It is in. Another object of the present invention is to provide a coated body having a coating film excellent in adhesion to a plastic substrate, water resistance and chemical resistance.

  As a result of intensive studies to achieve the above object, the inventors of the present invention are acrylic modified cellulose derivatives (A) obtained by graft polymerization or simply binding an acrylic component to a cellulose derivative, and grafting a specific acrylic component. An acrylic modified cellulose derivative (A) having an amount or a binding amount, a weight average molecular weight and a glass transition temperature, and a mixture of a cellulose derivative (B) other than the acrylic modified cellulose derivative and an acrylic resin (C), the mixture And a resin component containing at least one of a composition having a specific composition of the weight average molecular weight of the cellulose derivative (B) and the glass transition temperature of the acrylic resin (C). And using a resin composition having a total hydroxyl value of 7 to 100 mgKOH / g as a paint It found that the adhesion to plastic substrates, water resistance and chemical resistance to coating film excellent obtained, and have completed the present invention.

That is, the resin composition of the present invention is
An acrylic modified cellulose derivative (A) obtained by graft polymerization or simply bonding an acrylic component to a cellulose derivative, and the graft amount or the binding amount of the acrylic component in the acrylic modified cellulose derivative is 10 to 70% by mass ( Provided that the weight average molecular weight (Mw) of the acrylic modified cellulose derivative is 20,000 to 500,000, except when used in combination with a mixture of the cellulose derivative (B) other than the acrylic modified cellulose derivative and the acrylic resin (C). An acrylic modified cellulose derivative (A) having an acrylic component constituting the acrylic modified cellulose derivative having a glass transition temperature of 50 ° C. or higher, and a mixture of a cellulose derivative (B) other than the acrylic modified cellulose derivative and an acrylic resin (C) The cellulose derivative ( B) and the acrylic resin (C) have a mass ratio (B / C) of 90/10 to 30/70 (mass% / mass%) (except when used in combination with the acrylic modified cellulose derivative (A)). ), The cellulose derivative (B) has a weight average molecular weight (Mw) of 20,000 to 500,000 and the glass transition temperature of the acrylic resin (C) is at least 50 ° C. The resin component has a total acid value and hydroxyl value of 7 to 100 mgKOH / g, provided that the resin component is a cellulose derivative (B) other than the acrylic modified cellulose derivative (A) and the acrylic modified cellulose derivative. When both of the mixture with the acrylic resin (C) are included, the cellulose derivative other than the acrylic modified cellulose derivative (A) and the acrylic modified cellulose derivative The total amount of the acrylic component grafted or bound in the acrylic modified cellulose derivative in the total of the conductor (B) and the acrylic resin (C) and the total proportion of the acrylic resin (C) is 10 to 70% by mass. To do.

  In the suitable example of the resin composition of this invention, 0.2-13 mass% of nitrogen atoms are included with respect to solid content of the said resin composition.

  In another preferred embodiment of the resin composition of the present invention, the cellulose derivative constituting the acrylic modified cellulose derivative (A) and the cellulose derivative (B) are cellulose ether, cellulose ester, polyester modified cellulose derivative and polyurethane modified cellulose. It is at least one selected from the group consisting of derivatives.

  In another preferred embodiment of the resin composition of the present invention, a pigment is further included.

Further, the coated body of the present invention is a coated body having a plastic substrate and a coating film formed on the surface of the plastic substrate, the coating film is obtained from the above resin composition, and Formula (I):
X−Y = ΔH ≦ 2 grade (I)
[Wherein, X is the pencil hardness before chemical treatment, Y is the pencil hardness after chemical treatment, ΔH is the grade difference in pencil hardness before and after chemical treatment, where Is a treatment in which a sunscreen agent containing an ultraviolet absorber is applied to the surface of the paint film at a rate of 2.0 g / 100 cm ² and then left at a temperature of 60 ± 2 ° C. for 5 hours. Is characterized by satisfying the relationship of JIS K 5600-5-4: 1999 (ISO / DIS 15184: 1996) measured by pencil hardness.

  The pencil hardness specified in JIS K 5600-5-4: 1999 (ISO / DIS 15184: 1996) is 6B / 5B / 4B / 3B / 2B / B / HB / F / H / 2H, 3H, 4H, 5H, and 6H are specified in this order. That is, a coating film with a grade of 6B has the lowest pencil hardness, while a coating film with a grade of 6H has the highest pencil hardness.

  Further, the sunscreen agent means a substance or composition applied to the skin in order to protect the skin from damage caused by ultraviolet rays (for example, sunburn). In the present invention, among these sunscreen agents, an ultraviolet absorber. Means something. Moreover, it does not specifically limit as an ultraviolet absorber, For example, a salicylic acid ester derivative, a benzophenone derivative, a naphthalene derivative, a phenol derivative, a benzimidazole derivative, a dibenzoylmethane derivative etc. are mentioned. In addition, these ultraviolet absorbers are mix | blended independently or are used in combination of 2 or more types. Moreover, a sunscreen agent contains 2 mass% or more of ultraviolet absorbers normally. Sunscreens containing ultraviolet absorbers tend to dissolve or soften the coating film, and as sunscreens that have a particularly strong tendency, those containing 3% by mass or more of salicylic acid ester derivatives, and / or Or what contains 2 mass% or more of a benzophenone derivative is known.

  According to the resin composition of this invention, the resin composition which can form the coating film excellent in the adhesiveness to a plastic base material, water resistance, and chemical resistance can be provided.

  According to the coated body of the present invention, it is possible to provide a coated body having a coating film excellent in adhesion to a plastic substrate, water resistance and chemical resistance.

Hereinafter, the resin composition of the present invention will be described in detail. The resin composition of the present invention is
An acrylic modified cellulose derivative (A) obtained by graft polymerization or simply bonding an acrylic component to a cellulose derivative, and the graft amount or the binding amount of the acrylic component in the acrylic modified cellulose derivative is 10 to 70% by mass ( Provided that the weight average molecular weight (Mw) of the acrylic modified cellulose derivative is 20,000 to 500,000, except when used in combination with a mixture of the cellulose derivative (B) other than the acrylic modified cellulose derivative and the acrylic resin (C). An acrylic modified cellulose derivative (A) having an acrylic component constituting the acrylic modified cellulose derivative having a glass transition temperature of 50 ° C. or higher, and a mixture of a cellulose derivative (B) other than the acrylic modified cellulose derivative and an acrylic resin (C) The cellulose derivative ( B) and the acrylic resin (C) have a mass ratio (B / C) of 90/10 to 30/70 (mass% / mass%) (except when used in combination with the acrylic modified cellulose derivative (A)). ), The cellulose derivative (B) has a weight average molecular weight (Mw) of 20,000 to 500,000 and the glass transition temperature of the acrylic resin (C) is at least 50 ° C. The resin component has a total acid value and hydroxyl value of 7 to 100 mgKOH / g, provided that the resin component is a cellulose derivative (B) other than the acrylic modified cellulose derivative (A) and the acrylic modified cellulose derivative. When both of the mixture with the acrylic resin (C) are included, the cellulose derivative other than the acrylic modified cellulose derivative (A) and the acrylic modified cellulose derivative The total amount of the acrylic component grafted or bound in the acrylic modified cellulose derivative in the total of the conductor (B) and the acrylic resin (C) and the total proportion of the acrylic resin (C) is 10 to 70% by mass. To do. In addition, since the resin composition of this invention can form the coating film excellent in the adhesiveness to a plastic base material, water resistance, and chemical resistance, it is suitable as a coating material.

  The resin component contained in the resin composition of the present invention comprises at least one of the acrylic modified cellulose derivative (A) and a mixture of a cellulose derivative (B) other than the acrylic modified cellulose derivative and an acrylic resin (C). It is necessary to include.

  In the resin composition of the present invention, the resin component needs to have a total acid value and hydroxyl value of 7 to 100 mgKOH / g, and preferably 10 to 50 mgKOH / g. Here, the acid value and the hydroxyl value may be derived from any of the components constituting the resin component. If the sum of the acid value and hydroxyl value of the resin component is within the above specified range, a coating film having excellent water resistance can be formed. On the other hand, when the sum of the acid value and hydroxyl value of the resin component exceeds 100 mgKOH / g, the water resistance and moisture resistance of the coating film may be lowered, and the coating film may be whitened or blistered. In addition, since a hydroxyl group usually exists in a cellulose derivative, it is difficult to design the sum of the acid value and the hydroxyl value of the resin component to be less than 7 mgKOH / g.

  The acrylic modified cellulose derivative (A) is a compound obtained by graft polymerization or simply bonding an acrylic component to a cellulose derivative, and ordinary synthesis methods can be used for graft polymerization and bonding.

  In the acrylic modified cellulose derivative (A), as the cellulose derivative, cellulose ether, cellulose ester, polyester modified cellulose derivative, polyurethane modified cellulose derivative and the like are preferable. In addition, these cellulose derivatives may be used independently and may be used in combination of 2 or more type. The cellulose derivative is preferably a cellulose ester from the viewpoint of chemical resistance, and is preferably a polyester-modified cellulose derivative or a polyurethane-modified cellulose derivative from the viewpoint of particularly improving the adhesion to a plastic substrate.

  Examples of the cellulose ether include methyl cellulose, ethyl cellulose, benzyl cellulose, trityl cellulose, cyanoethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, aminoethyl cellulose, oxyethyl cellulose (also referred to as hydroxyethyl cellulose). Examples of the cellulose ester include fatty acid celluloses such as acetyl cellulose, cellulose propionate, cellulose butyrate, and cellulose acetate butyrate, nitrocellulose, cellulose sulfate, cellulose phosphate, and cellulose nitrate acetate.

  Polyester-modified cellulose derivatives include cellulose components such as cellulose ether and cellulose ester, and polyester components such as polytrimethylene terephthalate, polyethylene terephthalate, and polybutylene terephthalate (that is, components having a plurality of ester bonds in the main chain). It is a compound obtained by graft polymerization or simply bonding.

  The acrylic component and the polyester component can also be used together, and when the acrylic component or the polyester component is graft-polymerized or simply combined, other monomers such as styrene and vinyl ester are combined together. It can also be used.

  The polyurethane-modified cellulose derivative is a compound obtained by reacting an isocyanate prepolymer with a hydroxyl group of a cellulose derivative such as cellulose ether or cellulose ester. An isocyanate prepolymer is a compound containing an isocyanate group obtained by reacting a polyisocyanate with a hydroxyl group-containing compound. Here, the hydroxyl group-containing compound is a compound having one or more hydroxyl groups in the molecule. For example, a compound having one hydroxyl group in the molecule such as a polycondensate of 12-hydroxystearic acid, polyester polyol, Examples include compounds having a plurality of hydroxyl groups in the molecule such as ether polyols, acrylic polyols, and epoxy polyols, and polyisocyanates are compounds having a plurality of isocyanate groups. For example, hexamethylene diisocyanate, toluene diisocyanate, methylene diisocyanate, Examples thereof include diisocyanates such as range isocyanate and isophorone diisocyanate, and isocyanurates. In addition, since an isocyanate prepolymer is an acrylic component when an acrylic polyol is used as a polyol, the resulting polyurethane-modified cellulose derivative is included in the acrylic-modified cellulose derivative (A). Such polyurethane-modified cellulose derivatives are sometimes referred to as polyurethane / acryl-modified cellulose derivatives.

  In the acrylic modified cellulose derivative (A), the acrylic component is not limited to an isocyanate prepolymer obtained when an acrylic polyol is used as the above-mentioned polyol, but acrylic acid, methacrylic acid and its Including compounds selected from esters, amides, nitriles and the like, for example, compounds as shown in (a) to (g) below. Moreover, the said acrylic component can also use other monomers, such as a polyester component, styrene, a vinyl ester, for example together. In addition, these acrylic components may be used independently and may be used in combination of 2 or more types. In particular, since the acrylic-modified cellulose derivative (A) contains an acrylic component, the acrylic-modified cellulose derivative (A) has excellent adhesion to a plastic substrate as compared with other cellulose derivatives.

(A): ester of (meth) acrylic acid and alcohol having 1 to 24 carbon atoms For example, methyl methacrylate, 2-isocyanatoethyl methacrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) Acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) Examples include acrylate, isobornyl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, and the like.

(B): Monoesterified product of polyhydric alcohol and (meth) acrylic acid For example, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2,3-dihydroxybutyl (meth) acrylate, 4-hydroxy Examples thereof include butyl (meth) acrylate and polyethylene glycol mono (meth) acrylate.

(C): Carboxyl group-containing polymerizable unsaturated monomer Examples include acrylic acid, methacrylic acid, maleic acid, and maleic anhydride.

(D): Epoxy group-containing polymerizable unsaturated monomer Examples include glycidyl (meth) acrylate and 3,4-epoxycyclohexylmethyl (meth) acrylate.

(E): Aminoalkyl (meth) acrylate Examples include N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meth) acrylate, and the like. .

(F): (meth) acrylamide or a derivative thereof For example, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylamide, N, N-diethylaminoethyl (meth) acrylamide, N-dimethylaminopropyl (meth) acrylamide N-methylol acrylamide, N-methylol acrylamide methyl ether, N-methylol acrylamide butyl ether and the like.

(G): (Meth) acrylonitrile or a derivative thereof Examples thereof include (meth) acrylonitrile and 3-amino (meth) acrylonitrile.

  In the resin composition of the present invention, the acrylic-modified cellulose derivative (A) is an acrylic-modified cellulose derivative except when used in combination with a cellulose derivative (B) other than the acrylic-modified cellulose derivative and an acrylic resin (C). It is required that the amount of grafting or bonding of the acrylic component in the inside is 10 to 70% by mass, and preferably 20 to 50% by mass. If the amount of the acrylic component grafted or bonded is within the above specified range, chemical resistance, particularly resistance to sunscreen (hereinafter referred to as sunscreen resistance), and adhesion to a plastic substrate It is possible to form an excellent coating film. Here, when the graft amount or bonding amount of the acrylic component is less than 10% by mass, the adhesion to the plastic substrate is lowered, and the coating film is easily peeled off. In this case, since the viscosity of the resin composition of the present invention is increased, the coating workability is also lowered. On the other hand, when the grafting amount or bonding amount of the acrylic component exceeds 70% by mass, the chemical resistance of the coating film decreases. For this reason, when a chemical | medical agent is apply | coated to this coating film, this coating film will become easy to peel. Further, in this case, whitening, glossing and cracking of the coating film are likely to occur.

  In the resin composition of the present invention, the acrylic-modified cellulose derivative (A) needs to have a weight average molecular weight (Mw) of 20,000 to 500,000, and 25,000 to 150,000. Is particularly preferred. If the weight average molecular weight of the said acrylic modified cellulose derivative (A) is less than 20,000, the chemical resistance of the coating film obtained by the resin composition of this invention will fall remarkably. For this reason, when a chemical | medical agent is apply | coated to this coating film, the adhesiveness of a coating film will fall and peeling of a coating film will occur easily. Further, in this case, whitening, glossing and cracking of the coating film are likely to occur. On the other hand, when the weight average molecular weight of the acrylic modified cellulose derivative (A) exceeds 500,000, the viscosity of the resin composition of the present invention increases, and the coating workability of the resin composition decreases.

  In the resin composition of the present invention, the acrylic modified cellulose derivative (A) requires that the glass transition temperature of the acrylic component constituting the acrylic modified cellulose derivative is 50 ° C. or higher. When the glass transition temperature of the acrylic component is 50 ° C. or higher, the coating film is less likely to be softened at a high temperature, and chemical immersion is suppressed and chemical resistance of the coating film is improved.

In addition, in this invention, the glass transition temperature (Tg) of an acrylic component means what is calculated using the following FOX formula.
1 / Tg = W1 / Tg1 + W2 / Tg2 + ... + Wi / Tgi + ... + Wn / Tgn
In the FOX formula, Tg is a glass transition temperature (K) of a polymer composed of n types of monomers (acrylic components), and Tg (1, 2, i, n) is a glass transition temperature of a homopolymer of each monomer. (K), W (1, 2, i, n) is a mass fraction of each monomer, and W1 + W2 +... + Wi +.

  Moreover, the said cellulose derivative (B) is cellulose derivatives other than the said acrylic modified cellulose derivative (A), and a cellulose ether, a cellulose ester, a polyester modified cellulose derivative, a polyurethane modified cellulose derivative, etc. are preferable. In addition, these cellulose derivatives may be used independently and may be used in combination of 2 or more type. The cellulose derivative is preferably a cellulose ester from the viewpoint of chemical resistance, and is preferably a polyester-modified cellulose derivative or a polyurethane-modified cellulose derivative from the viewpoint of particularly improving the adhesion to a plastic substrate.

  In the cellulose derivative (B), the cellulose ether, cellulose ester, polyester-modified cellulose derivative and polyurethane-modified cellulose derivative are specifically the same as those described in the description of the acrylic-modified cellulose derivative (A). However, cellulose derivatives containing an acrylic component are excluded. When a polyester polyol is used as the polyol when the polyurethane-modified cellulose derivative is synthesized, the polyurethane-modified cellulose derivative may be referred to as a polyurethane / polyester-modified cellulose derivative.

  In the resin composition of the present invention, the cellulose derivative (B) needs to have a weight average molecular weight (Mw) of 20,000 to 500,000, particularly 25,000 to 150,000. preferable. If the weight average molecular weight of the said cellulose derivative (B) is less than 20,000, the chemical resistance of the coating film obtained by the resin composition of this invention will fall remarkably. For this reason, when a chemical | medical agent is apply | coated to this coating film, the adhesiveness of a coating film will fall and peeling of a coating film will occur easily. Further, in this case, whitening, glossing and cracking of the coating film are likely to occur. On the other hand, when the weight average molecular weight of the cellulose derivative (B) exceeds 500,000, the viscosity of the resin composition of the present invention increases, and the coating workability of the resin composition decreases.

  The acrylic resin (C) is not particularly limited, and can be obtained, for example, by polymerizing one or more acrylic components selected from acrylic acid, methacrylic acid and esters thereof, amides, nitriles, and the like. A polymer is mentioned. Specific examples of the acrylic component include compounds as shown in the above (a) to (g). The acrylic resin also includes a polymer obtained by polymerizing an acrylic component and another monomer such as styrene or vinyl ester. In addition, these acrylic resins may be used independently and may be used in combination of 2 or more type.

  Moreover, the said acrylic resin requires that a glass transition temperature (Tg) is 50 degreeC or more. When the glass transition temperature of the acrylic resin is 50 ° C. or higher, softening of the coating film at high temperatures is difficult to occur, so that chemical immersion is suppressed and chemical resistance of the coating film is improved.

In addition, in this invention, the glass transition temperature (Tg) of an acrylic resin means what is calculated using the following FOX formula.
1 / Tg = W1 / Tg1 + W2 / Tg2 + ... + Wi / Tgi + ... + Wn / Tgn
In the FOX formula, Tg is a glass transition temperature (K) of a polymer composed of n types of monomers, and Tg (1, 2, i, n) is a glass transition temperature (K) of a homopolymer of each monomer. Yes, W (1, 2, i, n) is the mass fraction of each monomer, and W1 + W2 +... + Wi +.

  The mixture of the cellulose derivative (B) and the acrylic resin (C) is a mass ratio (B / C) of the cellulose derivative (B) and the acrylic resin (C) except when used in combination with the acrylic-modified cellulose derivative (A). However, it is required that it is 90 / 10-30 / 70 (mass% / mass%) in conversion of resin solid content, and it is preferable that it is 80 / 20-50 / 50 (mass% / mass%). If the mass ratio of cellulose derivative (B) / acrylic resin (C) is within the above specified range, chemical resistance, particularly resistance to sunscreen (hereinafter referred to as sunscreen resistance), and plastic substrate It is possible to form a coating film having excellent adhesion to the film. Here, when the ratio of the cellulose derivative (B) to the total of the cellulose derivative (B) and the acrylic resin (C) exceeds 90% by mass, the adhesion to the plastic substrate is lowered and the coating film is peeled off. It becomes easy. In this case, since the viscosity of the resin composition of the present invention is increased, the coating workability is also lowered. On the other hand, when the ratio of the cellulose derivative (B) to the total of the cellulose derivative (B) and the acrylic resin (C) is less than 30% by mass, the chemical resistance of the coating film is lowered. For this reason, when a chemical | medical agent is apply | coated to this coating film, this coating film will become easy to peel. Further, in this case, whitening, glossing and cracking of the coating film are likely to occur.

  In addition, "resin solid content" here means the solid content of the resin component contained in the resin composition of this invention. In the present invention, the resin solid content is defined as the mass of the residue remaining after heating 1.0 g of the resin component at 105 ° C. ± 2 ° C. for 60 minutes.

  In the resin composition of the present invention, when the resin component includes both the acrylic modified cellulose derivative (A) and a mixture of the cellulose derivative (B) and the acrylic resin (C), the acrylic modified cellulose derivative (A), cellulose The total amount of the acrylic component grafted or bonded and the acrylic resin (C) in the acrylic modified cellulose derivative in the total of the derivative (B) and the acrylic resin (C) needs to be 10 to 70% by mass. It is preferable that it is 20-50 mass%. If the total amount of the acrylic component graft or bond and acrylic resin (C) is within the specified range, chemical resistance, particularly resistance to sunscreen (hereinafter referred to as sunscreen resistance) and A coating film excellent in adhesion to a plastic substrate can be formed. Here, if the total amount of the acrylic component graft or bond and the acrylic resin (C) is less than 10% by mass, the adhesion to the plastic substrate is lowered, and the coating film is easily peeled off. In this case, since the viscosity of the resin composition of the present invention is increased, the coating workability is also lowered. On the other hand, when the total proportion of the acrylic component graft or bond and the acrylic resin (C) exceeds 70% by mass, the chemical resistance of the coating film decreases. For this reason, when a chemical | medical agent is apply | coated to this coating film, this coating film will become easy to peel. Further, in this case, whitening, glossing and cracking of the coating film are likely to occur.

  In the resin composition of the present invention, the resin component is a resin component other than the acrylic modified cellulose derivative (A), the other cellulose derivative (B), and the acrylic resin (C) (hereinafter referred to as other resin component). Can be included). Examples of the other resin component include a polyurethane resin, a polyester resin, and a silicone resin, and the glass transition temperature (Tg) is particularly preferably 50 ° C. or higher. When a resin having a glass transition temperature of 50 ° C. or higher is used, the chemical resistance of the coating film is improved by suppressing chemical immersion in order to prevent the coating film from being softened at a high temperature.

  In the resin composition of the present invention, the resin components preferably have good compatibility with each other. When the resin components having low compatibility are combined, the storage stability of the resin composition of the present invention may be reduced. As a result, the resin composition may be fuzzy or the coating composition obtained from the resin composition may be coated. There is a risk that the appearance of the coating film may be impaired due to the film becoming glossy or whitening.

  It is preferable that the resin composition of this invention contains 0.2-13 mass% of nitrogen atoms with respect to solid content of this resin composition, and it is still more preferable that 1.0-11.5 mass% is included. The nitrogen atom present in the resin composition may be any of the acrylic-modified cellulose derivative (A), other cellulose derivatives (B) and acrylic resin (C), and other resins when other resins are included. From the viewpoint of improving the water resistance and moisture resistance of the coating film, those derived from the acrylic-modified cellulose derivative (A) and other cellulose derivatives (B) are preferable. Specific examples of the cellulose derivative containing a nitrogen atom include cyanoethyl cellulose, aminoethyl cellulose, nitrocellulose, cellulose nitrate acetate, polyurethane-modified cellulose derivative and the like, and among these, nitrocellulose is particularly preferable. The chemical resistance can be further improved by the presence of 0.2% by mass or more of nitrogen atoms in the solid content of the resin composition. On the other hand, when the nitrogen atom present in the solid content of the resin composition exceeds 13% by mass, the flexibility of the coating film is lowered, and the processability of the coating film such as weight drop resistance and bendability tends to be inferior. . Further, when the nitrogen atom is derived from the cellulose derivative and the content of the nitrogen atom exceeds 13% by mass with respect to the solid content of the resin composition, the resin composition is high in viscosity, and thus the coating property is inferior. Tend.

  The “solid content of the resin composition” as used herein means the solid content contained in the resin composition of the present invention. In the present invention, the solid content of the resin composition is defined as the mass of the residue remaining after 1.0 g of the resin composition is heated at 105 ° C. ± 2 ° C. for 60 minutes.

  The resin composition of the present invention may contain a curing agent and a curing accelerator for the purpose of crosslinking the resin component.

  Furthermore, the resin composition of the present invention preferably contains a pigment. The resin composition of the present invention is particularly suitable as a coating resin composition when it contains a pigment. Examples of the pigment include coloring pigments, extender pigments, metallic pigments, and the like, which can be appropriately selected according to the coloring and gloss of the coating film, coating workability, the strength of the coating film, physical properties, and the like. A known material can be used as the color pigment, and examples thereof include inorganic pigments such as titanium oxide and carbon black, and organic pigments such as phthalocyanine pigments and azo pigments. As the extender pigment, known materials can be used, and examples thereof include talc, mica, barium sulfate, clay, calcium carbonate and the like. Examples of metallic pigments include bright pigments or scaly pigments such as aluminum powder pigments, nickel powder pigments, gold powder, silver powder, bronze powder, copper powder, stainless steel powder pigments, mica (mica) pigments, graphite pigments, glass flake pigments, Examples include metal-coated glass powder, metal-coated mica powder, metal-coated plastic powder, and flaky iron oxide pigment. From the viewpoint of chemical resistance, the surface of the bright pigment or flaky pigment is an organic component and / or Or what was surface-treated with the inorganic component is preferable. In addition, when a pigment is not included, this resin composition can be used as a clear paint.

  Various drying means can be applied to the resin composition of the present invention, and various compositions such as a volatile drying type (lacquer) and a thermosetting type can be used. In addition to the resin component, curing agent, curing accelerator and pigment, the resin composition of the present invention includes additives usually used in the paint industry, such as solvents, surface conditioners, wetting agents, dispersing agents, Emulsifier, thickener, anti-settling agent, anti-skinning agent, anti-sagging agent, antifoaming agent, anti-coloring agent, leveling agent, drying agent, plasticizer, anti-fungal agent, antibacterial agent, insecticide, light stabilization An agent, an ultraviolet absorber, an antistatic agent, a conductivity imparting agent, and the like can be appropriately blended depending on the purpose. As these additives, commercially available products can be suitably used. In addition, the resin composition of this invention can be prepared by mixing a resin component and the various components suitably selected as needed. Further, when the resin composition of the present invention is a thermosetting type, it is prepared by dividing various components into a main ingredient component and a curing agent component. It can also be used as a mixed resin to be mixed.

  The resin composition of the present invention can form a coating film excellent in chemical resistance, in particular, resistance to sunscreen agents, and therefore, a plastic molded product in which human skin and hands are in contact for a long time, specifically automobiles and It is useful for painting interior and exterior members of motorcycles, members for home appliances such as audio, video and television, and members for office equipment such as mobile phones, printers and personal computers.

  The coating method of the resin composition of the present invention includes, for example, a step of applying the resin composition to the surface of a substrate and then forming a film by drying or the like. In addition, in the coating method of the resin composition of this invention, you may apply | coat a primer to a base material beforehand before application | coating of this resin composition other than apply | coating the said resin composition directly to a substrate surface. By applying the primer in advance, the adhesion between the coating film and the substrate can be improved.

  The method for applying the resin composition of the present invention is not particularly limited, and is a known application method such as dipping, spin coating, flow coating, roll coating, spray coating, blade coating, and air knife. Examples thereof include a coating method. Among these, the spray coating method and the roll coating method are preferable from the viewpoint of easily controlling the film thickness.

In the coating method of the resin composition of the present invention, the coating amount of the resin composition can be changed according to the type and use of the substrate, but is usually 20 to 400 g / m ² and 40 to 200 g / m ^2. m ² is preferable. In addition, the film thickness of the coating film formed on the substrate surface depends on the coating amount of the resin composition.

  In the coating method of the resin composition of the present invention, a coating film can be formed by drying or the like on the resin composition applied to the substrate surface. For example, the resin composition is volatilized. In the case of a dry resin composition, a coating film can be obtained by leaving the resin composition at a temperature of 5 ° C. or higher and lower than 70 ° C. after coating. Similarly, when the resin composition is a thermosetting resin composition, a coating film can be obtained by leaving the resin composition at a temperature of 5 ° C. or more and less than 70 ° C. after coating.

  In the coating method of the resin composition of the present invention, the substrate is not particularly limited, and various shapes of substrates can be selected according to the use of the substrate. Examples of the substrate include olefin polymers such as PPE (polyphenylene ether) resin, polystyrene resin, polypropylene, and polyethylene; polycarbonate resins; plastic substrates such as acrylic resins such as polymethyl methacrylate and ABS resins. Is mentioned.

Next, the coated body of the present invention will be described in detail. The coated body of the present invention is a coated body having a plastic substrate and a coating film formed on the surface of the plastic substrate, wherein the coating film is obtained from the above-described resin composition and has the following formula ( I):
X−Y = ΔH ≦ 2 grade (I)
[Wherein, X is the pencil hardness before chemical treatment, Y is the pencil hardness after chemical treatment, ΔH is the grade difference in pencil hardness before and after chemical treatment, where Is a treatment in which a sunscreen agent containing an ultraviolet absorber is applied to the surface of the paint film at a rate of 2.0 g / 100 cm ² and then left at a temperature of 60 ± 2 ° C. for 5 hours. Is characterized by satisfying the relationship of JIS K 5600-5-4: 1999 (ISO / DIS 15184: 1996) measured by pencil hardness. Here, since the coated body of the present invention is excellent in chemical resistance, in particular, resistance to sunscreen, it is a plastic molded product in which human skin and hands are in contact for a long time, specifically, interiors of automobiles and motorcycles. This is useful for members and exterior members, members for home appliances such as audio, video and television, and members for office equipment such as mobile phones, printers and personal computers.

  The coated body of the present invention includes a plastic substrate and a coating film formed on the surface of the plastic substrate. For example, the above-described resin composition is applied to the surface of the plastic substrate, and then dried or the like. It can be manufactured by forming a film. In addition, the said resin composition can be apply | coated by the above-mentioned coating method. Moreover, the said plastic base material is not specifically limited, According to the use of a coating body, the base material of various shapes can be selected. Examples of the plastic substrate include PPE (polyphenylene ether) resins, polystyrene resins, olefin polymers such as polypropylene and polyethylene; polycarbonate resins; acrylic resins such as polymethyl methacrylate and ABS resins. .

In the coated body of the present invention, the coating film needs to satisfy the relationship of the above formula (I), and usually the following formula (II):
X ≧ Y (II)
[Wherein X and Y are as defined in the above formula (I)]. Here, if the grade difference in pencil hardness of the coating film before and after chemical treatment is 2 grades or less, the hardness of the coating film can be maintained at a high level even after chemical treatment. Resistance to sunscreens can be imparted. In addition, in order to suppress the grade difference of the pencil hardness of the coating film before and after the chemical treatment to 2 grades or less, it is preferable to use the resin composition for the coating material for forming the coating film.

  Moreover, in the coated body of this invention, the said coating film needs to be obtained with the resin composition mentioned above. By using the resin composition for forming the coating film, a coating film satisfying the relationship of the formula (I) can be easily formed. Further, when the resin composition is used, it is not necessary to heat the paint at a temperature of 70 ° C. or higher in the paint drying step, and a film can be formed at a temperature of 5 ° C. or higher and lower than 70 ° C.

  In the coated body of the present invention, the coating film preferably contains 0.2 to 13% by mass of nitrogen atoms, and more preferably 1.0 to 11.5% by mass. The chemical resistance can be further improved by the presence of 0.2% by mass or more of nitrogen atoms in the coating film. On the other hand, when the nitrogen atom present in the coating film exceeds 13% by mass, the flexibility of the coating film is lowered, and the coating film tends to be inferior in workability such as weight drop resistance and bendability.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples. In addition, the acid value, the hydroxyl value, the heating residue, and the weight average molecular weight were measured by the following methods.

<Acid value>
The number of mg of potassium hydroxide required to neutralize free carboxylic acid in 1 g of resin solids was determined.

<Hydroxyl value>
After free acetylation in 1 g of resin solids was completely acetylated with acetic anhydride, the number of mg of potassium hydroxide required to neutralize it was determined.

<Remaining heating>
1.0 g of resin solution, precursor solution or resin composition was precisely weighed in an aluminum cup and dried in an oven at 105 ° C. for 60 minutes. After drying, the mass of the residue was precisely weighed, and the ratio of the mass of the residue to the original mass was determined as a heating residue (mass%).

<Weight average molecular weight>
The weight average molecular weight (Mw) was measured by GPC equipped with RI (manufactured by Tosoh Corporation; HLC-8220 GPC) using a TSKgel column (manufactured by Tosoh Corporation). As GPC conditions, tetrahydrofuran was used as a developing solvent, and measurement was performed at a flow rate of 0.35 ml / min and a temperature of 40 ° C. TSK standard polystyrene (manufactured by Tosoh Corporation) was used as a standard substance.

1. Preparation Example of Acrylic Resin According to the preparation example shown below, an acrylic resin was synthesized.

1-1. Resin solution A
(First step)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, etc., 40.0 parts by mass of butyl acetate (solvent) is placed, and this is heated and stirred. After reaching 110 ° C., methyl methacrylate (monomer) 28. 6 parts by weight, 11.5 parts by weight of butyl methacrylate (monomer), 2.5 parts by weight of 2-ethylhexyl acrylate (monomer), 1.2 parts by weight of 2-hydroxylethyl methacrylate (monomer) and tertiary butyl peroxy-2- A mixture obtained by mixing 0.8 parts by mass of ethyl hexanoate (polymerization initiator) in advance was added dropwise over 3 hours while stirring with heating to obtain a first mixture.

(Second step)
After completion of dropping, while maintaining 110 ° C., 0.4 parts by mass of tertiary butyl peroxy-2-ethylhexanoate (polymerization initiator) and 3.0 parts by mass of butyl acetate (solvent) are maintained in the first mixture. The mixture obtained by previously mixing was added dropwise over 1 hour to obtain a second mixture. The mixture was further stirred at 110 ° C. for 1.5 hours and then cooled. 12.0 parts by mass of butyl acetate (solvent) was added to the second mixture and stirred to obtain a resin solution A. The heating residue of the resin solution A is 45.0% by mass, and the hydroxyl group-containing acrylic resin (acrylic polyol) contained in the resin solution A has a hydroxyl value of 11.8 mgKOH / g and a weight average molecular weight. Was 48200, and the glass transition temperature was 64.8 ° C. (calculated by the FOX equation).

1-2. Resin solutions B to H
Resin solutions B to H were prepared in the same manner as the resin solution A except that the compounds shown in Table 1 were used. In addition, Table 1 shows the heating residue, acid value, hydroxyl value, weight average molecular weight, and glass transition temperature of the resin solution.

  In Table 1, the formulation of the resin solution is shown in parts by mass.

2. Preparation Example of Acrylic Modified Cellulose Derivative (A) According to the following preparation example, an acrylic modified cellulose derivative and a polyurethane / acryl modified cellulose derivative were synthesized.

2-1. Preparation of acrylic modified cellulose derivative 2-1-1. Resin solution I
(First step)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, etc., 16.0 parts by mass of butyl acetate and cellulose ester [RS1 / 8 diluted with butyl acetate (manufactured by KOREA CNC LTD., Nitrocellulose) were used. . In addition, the heating residue in RS1 / 8 after dilution is 38% by mass. 63 parts by mass were added, and these were heated and stirred. After reaching 75 ° C., 0.1 parts by mass of 2-isocyanatoethyl methacrylate was added to obtain a first mixture. The first mixture was further stirred at 75 ° C. for 1 hour, and then 2.5 parts by mass of methyl methacrylate (monomer), 1.7 parts by mass of butyl methacrylate (monomer), 2-ethylhexyl acrylate (monomer) ) 0.1 parts by mass, 0.1 part by mass of 2-hydroxylethyl methacrylate (monomer) and 1.0 part by mass of tertiary butyl peroxy-2-ethylhexanoate (polymerization initiator) were obtained in advance. The mixture was added dropwise over 3 hours to obtain a second mixture.

(Second step)
After completion of dropping, while maintaining 75 ° C., 0.5 parts by mass of tertiary butyl peroxy-2-ethylhexanoate (polymerization initiator) and 3.0 parts by mass of butyl acetate were previously mixed in the second mixture. The resulting mixture was added dropwise over 1 hour to obtain a third mixture. The mixture was further stirred at 75 ° C. for 3 hours and then cooled. 12.0 parts by mass of butyl acetate was added to the third mixture and stirred to obtain a resin solution I. In addition, the heating residue of the resin solution I is 29.9% by mass, and the acrylic modified cellulose derivative contained in the resin solution I has a hydroxyl value of 33.2 mgKOH / g and a weight average molecular weight of 36300. The nitrogen atom content contained in the solid content of the resin solution was 9.5% by mass. The graft amount of the acrylic component in the acrylic modified cellulose derivative is 20% by mass, and the glass transition temperature (Tg) of the acrylic component constituting the acrylic modified cellulose derivative is 61.1 according to the FOX formula. ° C. The results are shown in Table 2. In Table 2, the formulation of the resin solution is shown in parts by mass.

* 1 RS1 / 8 diluted with butyl acetate so that the heating residue is 38% by mass [where RS1 / 8 is KOREA CNC LTD. The nitrogen content in the nitrocellulose is 12.2% by mass, and the content of isopropanol alcohol in RS1 / 8 is 30% by mass. ]

2-2. Polyurethane / acryl-modified cellulose derivative 2-2-1. Preparation Example of Precursor Solution X In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and the like, 100 parts by mass of the resin solution A was heated and stirred. After reaching 100 ° C., hexamethylene was added here. A mixture obtained by previously mixing 1.2 parts by mass of diisocyanate (polyisocyanate) and 1.5 parts by mass of butyl acetate (solvent) was added dropwise over 1 hour. After completion of dropping, stirring was continued at 100 ° C. for 5 hours, followed by cooling to obtain a precursor solution X. In addition, the heating residue of the precursor solution X was 45 mass%, and the weight average molecular weight of the isocyanate prepolymer contained in the precursor solution X was 52,000.

2-2-2. Preparation example of resin solution J (first step)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and the like, 15.00 parts by mass of methyl ethyl ketone and cellulose ester [RS1 / 8 diluted with butyl acetate (manufactured by KOREA CNC LTD., Nitrocellulose) were used. In addition, the heating residue in RS1 / 8 after dilution is 38% by mass. ] 61.20 parts by mass were added, and these were heated and stirred. After reaching 75 ° C., 12.90 parts by mass of the precursor solution X was added dropwise over 3 hours. After completion of the dropwise addition, the reaction was continued until no isocyanate group could be confirmed by IR, followed by cooling to obtain a reaction mixture.

(Second step)
After cooling, 10.90 parts by mass of methyl ethyl ketone was added to the reaction mixture and stirred to obtain a resin solution J. The heating residue of the resin solution J is 29.1% by mass, and the polyurethane / acryl-modified cellulose derivative contained in the resin solution J has a hydroxyl value of 31.8 mgKOH / g and a weight average molecular weight of 130500. The nitrogen atom content contained in the solid content of the resin solution was 9.6% by mass. The amount of the acrylic component bound in the polyurethane / acryl-modified cellulose derivative is 20% by mass, and the glass transition temperature (Tg) of the acrylic component constituting the polyurethane / acryl-modified cellulose derivative is determined by the FOX formula. It was 64.8 ° C. The results are shown in Table 3. In Table 3, the formulation of the resin solution is shown in parts by mass.

2-2-3. Resin solution K ~ M
Resin solutions K to M were prepared in the same manner as the resin solution J except that the compounds shown in Table 3 were used. The properties of these resin solutions are shown in Table 3.

3. Preparation Example of Cellulose Derivative (B) Other than Acrylic Modified Cellulose Derivative According to the preparation example shown below, a polyurethane / polyester modified cellulose derivative was synthesized.

3-1. Preparation example of polyurethane / polyester-modified cellulose derivative 3-1-1. Preparation Example of Precursor Solution Y In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, etc., 123 parts by mass of butyl acetate (solvent) was placed and stirred, and then Byron 200 (Toyobo polyester polyol, Hydroxyl value: 9 mg KOH / g, glass transition temperature: 67 ° C.) 100 parts by mass was added and dissolved to obtain a first mixture. The first mixture was heated and stirred, and after reaching 100 ° C., a mixture obtained by previously mixing 1.8 parts by mass of hexamethylene diisocyanate (polyisocyanate) and 1.4 parts by mass of butyl acetate (solvent) in advance. Was added dropwise over 1 hour. After completion of the dropping, stirring was continued at 100 ° C. for 5 hours, followed by cooling to obtain a precursor solution Y. In addition, the heating residue of the precursor solution Y was 45 mass%, and the weight average molecular weight of the isocyanate prepolymer contained in the precursor solution Y was 49000.

3-1-2. Resin solution N
(First step)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and the like, 15.00 parts by mass of methyl ethyl ketone and cellulose ester [RS1 / 8 diluted with butyl acetate (manufactured by KOREA CNC LTD., Nitrocellulose) were used. In addition, the heating residue in RS1 / 8 after dilution is 38% by mass. ] 61.20 parts by mass were added, and these were heated and stirred. After reaching 75 ° C., 12.90 parts by mass of the precursor solution Y was added dropwise over 3 hours. After completion of the dropwise addition, the reaction was continued until no isocyanate group could be confirmed by IR, followed by cooling to obtain a reaction mixture.

(Second step)
After cooling, 10.90 parts by mass of methyl ethyl ketone was added to the reaction mixture and stirred to obtain a resin solution N. The heating residue of the resin solution N is 29.1% by mass, and the polyurethane / polyester-modified cellulose derivative contained in the resin solution N has a hydroxyl value of 31.8 mgKOH / g and a weight average molecular weight of 129200. The nitrogen atom content contained in the solid content of the resin solution was 9.5% by mass. The results are shown in Table 4. In Table 4, the formulation of the resin solution is shown in parts by mass.

3-1-3. Resin solutions O and P
Resin solutions O and P were prepared in the same manner as the resin solution N except that the compounds shown in Table 4 were used. The properties of these resin solutions are shown in Table 4.

* 2 Diluted Eastman ™ Cellulose Acetate Butyrate (CAB-381-2) with methyl ethyl ketone so that the heating residue is 20% by mass [where Eastman ™ Cellulose Acetate Butyrate (CAB-381-2) is Eastman This is cellulose acetate butyrate manufactured by Chemical Company. ]

4). Preparation of Resin Composition ( Reference Examples 1 to 43, Examples 44 to 46, Reference Example 47, Examples 48 to 49, Reference Examples 50 to 53, Comparative Examples 1 to 15)
In accordance with the formulation shown in Tables 5 to 12, raw materials were mixed in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and the like, and then dissolved at 75 ° C. to prepare a resin composition. In addition, in Tables 5-12, the compounding prescription of a resin composition is shown by a mass part.

5. Preparation of resin composition ( Reference Examples 54 to 57)
According to the formulation shown in Table 13, a cellulose derivative and an acrylic resin were mixed in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, etc., and then dissolved at 75 ° C. to prepare a resin composition. . After the obtained resin composition was cooled to room temperature, additives such as a pigment and a surface conditioner were mixed in the resin composition and dispersed by a known method to prepare a resin composition. In Table 13, the formulation of the resin composition is shown in parts by mass.

  In addition, regarding a resin composition, the sum total of the acid value of a resin component and a hydroxyl value is shown to Tables 5-13. When the acrylic modified cellulose derivative (A) is used, the acrylic component grafting amount or binding amount in the acrylic modified cellulose derivative, the weight average molecular weight (Mw) of the acrylic modified cellulose derivative, and the acrylic constituting the acrylic modified cellulose derivative. When the glass transition temperature of the component is shown together and a mixture of the cellulose derivative (B) and the acrylic resin (C) is used, the mass ratio (B / C) of the cellulose derivative (B) and the acrylic resin (C), cellulose The weight average molecular weight (Mw) of a derivative (B) and the glass transition temperature of an acrylic resin (C) are shown together. Further, when the acrylic modified cellulose derivative (A) is used in combination with a mixture of the cellulose derivative (B) and the acrylic resin (C), the acrylic modified cellulose derivative (A), the cellulose derivative (B), and the acrylic resin (C). The total amount of the acrylic component grafted or bound in the acrylic modified cellulose derivative in the total and the acrylic resin (C) is also shown.

6). Coating film formation Using a 4 mil applicator, the resin composition was applied to an ABS resin plate at a coating amount such that the dry film thickness was 30 to 40 μm, allowed to stand for 10 minutes, and then at 60 ° C. for 30 minutes. It was made to dry and the coating film was formed on the ABS resin board. Regarding coating film obtained, coating film appearance, chemical resistance evaluation (coating film appearance after chemical treatment and pencil hardness before and after chemical treatment), adhesion and water resistance, and coating film (solid content of resin composition) The nitrogen atom content contained in was measured and evaluated by the following method. The results are shown in Tables 5-13. In addition, since the resin composition of Comparative Examples 3, 4 and 15 had poor coating workability and was difficult to coat, the coating film characteristics were not evaluated.

<Appearance of coating film>
About the external appearance of the coating film, it determined visually by the following evaluation criteria.
A: A smooth coating film with no coating film defects.
(Triangle | delta): Leveling property is not enough and a film thickness is non-uniform | heterogenous.
X: Painting workability is poor and painting is difficult.

<Evaluation of chemical resistance (coating appearance after chemical treatment)>
1. Sunscreen agent [trade name: Ultrashear Dry Touch Sun Block SPF45, manufactured by Neutrogena, UV absorber: salicylic acid ester derivative (10% by mass) and benzophenone derivative (5% by mass)] on the surface of the coating film. It was applied at a rate of 0 g / 100 cm ² and then left for 5 hours in a dryer without forced convection at a temperature of 60 ± 2 ° C. for chemical treatment. Then, it washed with water, the sunscreen agent was removed, and finally the external appearance of the coating film after chemical processing was visually determined on the following evaluation criteria.
A: There is no change in the appearance of the coating film.
○: The gloss of the coating film slightly decreases.
(Triangle | delta): The glossiness of a coating film falls remarkably.
X: A coating film whitens.

<Evaluation of chemical resistance (pencil hardness before and after chemical treatment)>
First, in accordance with JIS K 5600-5-4: 1999 (ISO / DIS 15184: 1996), the pencil hardness of the coating before chemical treatment is determined with a scratch hardness test pencil (Uni MITSUBISHI, manufactured by Mitsubishi Pencil Co., Ltd.). did. Next, the same chemical treatment as the coating appearance evaluation after chemical treatment was performed on the coating film surface of the coated body. Then, it washed with water, the sunscreen agent was removed, and finally the pencil hardness of the coating film after chemical processing was determined by the same method.

<Adhesiveness>
A straight cut is made with a cutter knife at a cut angle of 60 ° on the surface of the coating film horizontal to the ABS resin plate, and a cut is made again at an angle of 60 ° with respect to the cut. Thereafter, the cellophane tape is firmly attached so as to cover the cut, and the cellophane tape is peeled off at 45 ° with respect to the coating film surface. After removing the cellophane tape, the degree of peeling of the coating film was visually determined according to the following evaluation criteria.
○: There is no peeling of the coating film.
(Triangle | delta): 1/3 of the coating-film surface of a notch part peels.
X: The coating film surface of a notch part peels completely.

<Water resistance>
First, it was visually confirmed that there was no appearance defect on the coating film surface. The surface of the coating film was cut into a strip of 3 × 5 cm, used as a test piece, dried at 80 ° C. for 5 hours, and then left to stand at 25 ° C. for 24 hours while immersed in pure water. The film was taken out, the surface was wiped off, and the appearance of the coating film was visually determined according to the following evaluation criteria.
○: There is no change in the coating film appearance.
X: Swelling and whitening of the coating are observed.

<Nitrogen atom content>
The nitrogen atom content in the coating film was measured according to the following measurement procedure using a fully automatic elemental analyzer (2400II manufactured by PerkinElmer) in accordance with JIS M8819: 1997.
First, a sample of 2 mg to 3 mg is prepared, pure oxygen is fed into a combustion tube at about 950 ° C. in a helium atmosphere as a carrier gas, the compound constituting the sample is completely burned, and the carbon atom ( the C) to CO _2, nitrogen atoms (N) in _{N 2,} to convert the hydrogen atoms (H) in _{H 2} O. Excess oxygen is converted into copper oxide by reduced copper in the reducing tube, and halogen and sulfur are converted into silver halide and silver sulfide through a silver grain column and trapped respectively. Therefore, the gas remaining after complete combustion is a mixed gas of CO ₂ , N ₂ , H ₂ O and helium. The mixed gas sequentially passes through the measurement cell. A filament is placed in the measurement cell. H ₂ O absorption tube as mixed gas, remove _{H 2} O. There are measurement cells before and after that, and the difference in resistance value is converted into a count and output. Then, the absorption tube CO ₂ as a gas to remove CO _2. Similarly, the difference between the resistance values before and after that is converted into a count and output. Further, when obtaining the count of N ₂ , helium in the delay coil is first sent to the measurement cell, the resistance value of helium is measured, and then the mixed gas is sent to the measurement cell, and the resistance value of the mixed gas is measured. Is measured. The difference between the resistance values is converted, and the count value of N ₂ is calculated. Using a count obtained with a standard substance having a known composition ratio, correction by atmospheric pressure is performed, and a sensitivity coefficient for each element is determined. The nitrogen content in the sample is calculated using the obtained sensitivity coefficient.

* A The weight average molecular weight of the cellulose derivative used is described in the column of “weight average molecular weight of cellulose derivative I”, but when two types of cellulose derivatives are used, the weight average molecular weight of the cellulose derivative described above in the table is It is described in the column “weight average molecular weight of cellulose derivative I”, and the weight average molecular weight of the cellulose derivative described below is described in the column “weight average molecular weight of cellulose derivative II”.
* 3 Diluted Eastman ™ Cellulose Acetate Butyrate (CAB-321-0.1) with methyl ethyl ketone so that the heating residue is 20% by mass [Here, Eastman ™ Cellulose Acetate Butyrate (CAB-321-0.1) Is cellulose acetate butyrate manufactured by Eastman Chemical Company. ]
* 4 Diluted Eastman ™ Cellulose Acetate Butyrate (CAB-551-0.01) with methyl ethyl ketone so that the heating residue is 20% by mass [Here, Eastman ™ Cellulose Acetate Butyrate (CAB-551-0.01) Is cellulose acetate butyrate manufactured by Eastman Chemical Company. ]
* 5 Eastman ™ Cellulose Acetate Butyrate (CAB-553-0.4) diluted with methyl ethyl ketone so that the heating residue is 20% by mass [Here, Eastman ™ Cellulose Acetate Butyrate (CAB-553-0.4) Is cellulose acetate butyrate manufactured by Eastman Chemical Company. ]
* 6 RS1 / 16 diluted with butyl acetate so that the heating residue is 38% by mass [where RS1 / 16 is KOREA CNC LTD. The nitrogen content in the nitrocellulose is 12.2% by mass, and the content of isopropyl alcohol in RS 1/16 is 30% by mass. ]
* 7 RS20 diluted with butyl acetate so that the heating residue is 38% by mass [wherein RS20 is KOREA CNC LTD. The nitrogen content in the nitrocellulose is 12.2% by mass, and the content of isopropanol alcohol in the RS 20 is 30% by mass. ]
* 8 RS500 diluted with butyl acetate so that the heating residue is 38% by mass [where RS500 is KOREA CNC LTD. The nitrogen content in the nitrocellulose is 12.2% by mass, and the content of isopropyl alcohol in the RS 500 is 30% by mass. ]
* 9 Surface conditioner, DISPERBYK-161, manufactured by BYK-Chemie, solid content: 30%.
* 10 Pigment, TI-PURE R-960, manufactured by DuPont, titanium dioxide.
* 11 Pigment, MA-100, manufactured by Mitsubishi Chemical Corporation, carbon black.
* 12 Pigment, F.I. X1690, manufactured by Toyo Aluminum Co., Ltd., an aluminum paste surface-treated with organic matter.

Claims (5)

Acrylic-modified cellulose derivative (A) obtained by graft polymerization or simply binding an acrylic component to a cellulose derivative, and the graft amount or binding amount of the acrylic component in the acrylic-modified cellulose derivative is 10 to 70% by mass, An acrylic modified cellulose derivative (A) having a weight average molecular weight (Mw) of the acrylic modified cellulose derivative of 20,000 to 500,000 and a glass transition temperature of the acrylic component constituting the acrylic modified cellulose derivative of 50 ° C. or higher is used as a resin component. The resin component is a resin composition having a total acid value and hydroxyl value of 7 to 100 mgKOH / g, and contains 0.2 to 13% by mass of nitrogen atoms based on the solid content of the resin composition. see, be characterized in that nitrogen atom is derived from acrylic-modified cellulose derivative (a) Resin composition. Furthermore, it is a mixture of a cellulose derivative (B) other than the acrylic-modified cellulose derivative and an acrylic resin (C), and the weight average molecular weight (Mw) of the cellulose derivative (B) is 20,000 to 500,000, and the acrylic resin (C) containing a mixture having a glass transition temperature of 50 ° C. or higher as a resin component,
However, when the resin component contains both the acrylic modified cellulose derivative (A) and a mixture of a cellulose derivative (B) other than the acrylic modified cellulose derivative and an acrylic resin (C), the acrylic modified cellulose derivative (A) The amount of acrylic component in the graft or the amount of binding is not 10 to 70% by mass, but the total of acrylic modified cellulose derivative (A), cellulose derivative other than acrylic modified cellulose derivative (B), and acrylic resin (C) total proportion from 10 to 70% by mass of the grafted amount or binding amount, and an acrylic resin acrylic component in the acryl-modified cellulose derivative (a) (C) occupied is,
It said nitrogen atom, the resin composition according to claim 1, characterized that you derived from at least one resin of the acryl-modified cellulose derivative (A) and cellulose derivatives other than the acrylic modified cellulose derivative (B) object.   The cellulose derivative constituting the acrylic modified cellulose derivative (A) and the cellulose derivative (B) are at least one selected from the group consisting of cellulose ether, cellulose ester, polyester modified cellulose derivative and polyurethane modified cellulose derivative. The resin composition according to claim 2.   The resin composition according to claim 1, further comprising a pigment. A coated body having a plastic substrate and a coating film formed on the surface of the plastic substrate, wherein the coating film is obtained by the resin composition according to any one of claims 1 to 4, And the following formula (I):
X−Y = ΔH ≦ 2 grade (I)
[Wherein, X is the pencil hardness before chemical treatment, Y is the pencil hardness after chemical treatment, ΔH is the grade difference in pencil hardness before and after chemical treatment, where Is a treatment in which a sunscreen agent containing an ultraviolet absorber is applied to the surface of the paint film at a rate of 2.0 g / 100 cm ² and then left at a temperature of 60 ± 2 ° C. for 5 hours. Is a pencil hardness measured in accordance with JIS K 5600-5-4: 1999 (ISO / DIS 15184: 1996)].