JPH0422172B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a new and useful resin composition for coating plastics, and more specifically, it contains a specific drying oil-fatty acid-modified vinyl copolymer as an essential component, a cellulose derivative, an ultraviolet absorber, and a dryer and/or The present invention also relates to a resin composition for coating plastics, which also contains a polyisocyanate or an amino resin, and has excellent gloss, drying properties, and texture, and is less likely to attack the surface of the material to be coated, that is, the surface of plastics. Consumption of plastics as lightweight or energy-saving materials continues to increase in various fields such as automobiles, home appliances, and miscellaneous goods. Furthermore, from the point of view of adding high value, it is possible to apply coating to the surface of the material.
It is commonly practiced. Currently, paints for plastics include:
There are lutzker-based materials that do not participate in cross-linking reactions, urethane-based materials that involve cross-linking reactions, and even those that are mixed with amino resins for heat-resistant materials. Among these, urethane-based materials Because it is low-temperature curable and has excellent coating performance, demand is increasing for both top coating and undercoating applications. However, even with this urethane-based paint, polystyrene, ABS,
For coated materials with poor solvent resistance, such as polycarbonate or "Noryl" (polyphenylene oxide manufactured by General Electric Company, USA), whitening phenomenon, occurrence of solvent cracks, and damage to the surface of the coated material may occur. Although the coating film performance is good, it is often necessary to impose certain restrictions on the materials to be coated that can be used or on the conditions of use, such as the need to apply an undercoat beforehand. Therefore, there is a strong desire in the industry for a urethane paint for plastics that has fewer defects. By the way, lacquer-based paints have been used as paints for plastics for a long time, and while they are less likely to attack the material being coated and are quick-drying and easy to use, they are not as good in terms of film performance, gloss, or appearance as those of urethane-based paints. Since it does not participate in the crosslinking reaction, the coating performance is also several orders of magnitude inferior to urethane-based materials, and materials with relatively good heat resistance such as FRP or PBT For this purpose, heat-curing type products that are combined with amino resins are also used, but it is desired that these products be better in terms of gloss, texture, etc. Therefore, there is a desire for a coating system that can compensate for the deficiencies of both lacquer-based and urethane-based paints, and that can also improve the deficiencies of amino resin combination systems. Separately, a method of obtaining an air-curable resin by adding a drying oil fatty acid to an epoxy group-containing acrylic copolymer has already been disclosed in British Patent No. 767476; In order to solve the problem that the resulting resin lacks gloss due to insufficient wetting to the pigment, methods such as those described in JP-A-53-51232 and JP-A-53-99231 were proposed. It can be said that this is an improved method. However, in each of the above improvement methods, the drying oil fatty acid is added to the glycidyl group in the acrylic resin, and then esterified with dicarboxylic anhydride such as tetrahydrophthalic anhydride. (1) production of an acrylic copolymer, (2) modification by addition of a drying oil fatty acid to the copolymer, and (3) esterification of the fatty acid-modified copolymer with dicarboxylic anhydride. This method cannot be said to be a preferable method because it lengthens the total reaction time consisting of several steps and complicates reaction control, resulting in increased production costs. However, in view of the above-mentioned actual situation, the present inventors added a drying oil-fatty acid-modified vinyl copolymer that has good wettability to pigments and excellent gloss by a simpler method. As a result of extensive research into using the modified copolymer to obtain a resin composition for coating plastics that is quick-drying, has excellent gloss and texture, and does not easily attack the surface of the material to be coated, the present invention has been developed. I have reached the point where I have completed it. That is, the present invention uses 5 to 25% by weight of an epoxy group-containing vinyl monomer and 0 to 25% by weight of an aromatic vinyl monomer.
60% by weight, 0 to 10% by weight of an alkyd resin having copolymerizable unsaturated bonds, and 5 to 95% by weight of other vinyl monomers copolymerizable with each of the above-mentioned vinyl monomers, and then the thus obtained A modified vinyl copolymer (A) obtained by adding 5 to 60 parts by weight of a drying oil fatty acid having an iodine value of 100 to 200 to 100 parts by weight of the epoxy group-containing vinyl copolymer (A). 60 to 100% by weight and 0 to 40% by weight of cellulose derivative (B), and further 0 to 10% based on the weight of the mixture
It has excellent gloss, dryness and texture, and is made by blending an ultraviolet absorber (C), or further blending a dryer (D) and/or a polyisocyanate or amino resin (E). To provide a resin composition for coating plastics that does not easily attack the coating film on the surface of a material to be coated. Here, typical drying oil fatty acids with an iodine value of 100 to 200 include cottonseed oil, soybean oil, rice sugar oil, dehydrated castor oil, linseed oil,
Fatty acids from natural oils and fats such as tall oil or Chinese tung oil, "Hi-Jien", "Hi-Jien H", "Hi-Jien S", and "SK Conjugated Fatty Acid #20" [all manufactured by Soken Chemical Co., Ltd.]
product] or “PAMOLYN 200,
Synthetic drying oil fatty acids such as ``300'' (product of Hercules Co., Ltd., USA), etc., can be used alone or in combination in any proportion, and in order to adjust the iodine value of such fatty acid systems. , in some cases with an iodine value such as coconut oil fatty acids, castor oil fatty acids, octylic acid, lauric acid, ``versateic acid'' (synthetic drying oil fatty acid manufactured by Siel, Netherlands), stearic acid or hydroxystearic acid. Fatty acids or saturated fatty acids having a molecular weight of less than 100% can be used in combination with drying oil fatty acids such as those listed above, as long as the amount is within a range that does not impair the air drying properties of the resulting modified vinyl copolymer (A). Of course. The appropriate amount of the drying oil fatty acid to be used is 5 to 60 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the epoxy group-containing vinyl copolymer. If the amount used is less than 5 parts by weight, the purpose-modified copolymer (A) will have poor air curing properties,
Since the paint film cannot have a sufficient three-dimensional structure, its physical properties and solvent resistance will deteriorate.
On the other hand, if the amount exceeds 60 parts by weight, yellowing becomes more likely and weather resistance decreases, and as a result of excessive crosslinking of the resulting coating film, flexibility is lost and the coating film becomes brittle. Therefore, neither of these methods can be put to practical use. Next, we will discuss the above-mentioned epoxy group-containing vinyl copolymers. First, typical epoxy group-containing vinyl monomers include glycidyl (meth)acrylate, β-methylglycidyl (meth)acrylate, and (meth)acrylate. α,β- such as allyl glycidyl ether, unsaturated mono- or dicarboxylic acids such as (meth)acrylic acid, fumaric acid, maleic acid or itaconic acid, or monoesters of such unsaturated dicarboxylic acids and monohydric alcohols. Ethylenically unsaturated carboxylic acids, carboxyl group-containing compounds such as "HA-MP" or "HOA-HS" [all of which are carboxyl group-containing acrylic monomers manufactured by Osaka Organic Chemical Co., Ltd.], or mono-2-(meth) )
Hydroxyl group-containing vinyl monomers such as acryloyloxyethyl phthalate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or di-2-hydroxyethyl fumarate and maleic acid, phthalic acid, tetrahydrophthalic acid, hexa By equimolar addition reaction with polycarboxylic acids (anhydrides) such as hydrophthalic acid, benzenetricarboxylic acid, "hymic acid" (product of Hitachi Chemical Co., Ltd.), dodecynylsuccinic acid, succinic acid, or tetrachlorophthalic acid. For various unsaturated carboxylic acids such as adducts obtained by
"Epcron 200, 400, 441, 850 or 1050"
[Epoxy resin manufactured by Dainippon Ink and Chemicals Co., Ltd.]
"Epicote 828, 1001 or 1004" (epoxy resin manufactured by Ciel), "Araldite 6071 or
6084” (epoxy resin manufactured by Ciba Geigy, Switzerland), “Chitsusonok 221” (epoxy compound manufactured by Chitsuso Corporation), or “Denacol EX-611” (epoxy compound manufactured by Nagase Sangyo Co., Ltd.), There are epoxy group-containing polymerizable compounds obtained by addition-reacting various polyepoxy compounds having at least two epoxy groups in one molecule in equimolar ratios, and these can be used alone or in combination of two or more. However, considering reactivity, number of reaction steps, viscosity or price of the final product, relatively low molecular weight types such as glycidyl (meth)acrylate and β-methylglycidyl (meth)acrylate are recommended. These monomers are the easiest to use. The epoxy group-containing vinyl monomer is used in a range of 5 to 25% by weight, but since the epoxy group in the monomer participates in the reaction with the drying oil fatty acid as mentioned above, the amount of the monomer used is limited. Needless to say, it should be determined mainly depending on the amount of the drying oil fatty acid used, and it is usually used in a ratio that provides epoxy groups in the range of 1.0 to 1.25 equivalents per 1 equivalent of the drying oil fatty acid carboxyl group. However, it is preferable from the viewpoint of reaction rate and the possibility of preventing the adverse effects of residual carboxyl groups on the coating film. In addition, the above-mentioned alkyd resin having a copolymerizable unsaturated bond can be used not only for pigments with low oil absorption such as titanium oxide and Bengara, but also for organic pigments such as quinacridone, phthalocyanine, and azo. It is used when it is desired to improve the dispersibility of pigments with relatively high oil absorption and poor dispersibility, such as carbon black, and in that sense, the alkyd resin has little effect on coating film performance itself. It can be said that it is not involved. As the alkyd resin, either one modified with oil or fatty acid, or a so-called oil-free alkyd resin that is not modified with these can be used, but in the present invention,
Among these alkyd resins, those having an unsaturated bond copolymerizable with each vinyl monomer are particularly suitable in the present invention. The alkyd resins include saturated fatty acids such as octylic acid, lauric acid, stearic acid or "versatynic acid"; unsaturated fatty acids such as oleic acid, linoleic acid, linoleic acid, eleostearic acid or ricinoleic acid;
200, 300'', Chinese tung oil (fatty acid), linseed oil (fatty acid), dehydrated castor oil (fatty acid), tall oil (fatty acid), cottonseed oil (fatty acid), soybean oil (fatty acid), olive oil (fatty acid), safflower oil ( semi-drying oils (fatty acids) such as castor oil (fatty acids) or rice sugar oil (fatty acids) or non-drying oils such as hydrogenated coconut oil (fatty acids), coconut oil (fatty acids) or palm oil (fatty acids) Using one type or a mixture of two or more types of oil or fatty acids such as oil (fatty acid),
Or without using ethylene glycol, propylene glycol, glycerin, trimethylolethane, trimethylolpropane, neopentyl glycol, 1,6-hexanediol, 1,
One or more polyhydric alcohols such as 2,6-hexanetriol, pentaerythritol or sorbitol, and benzoic acid, p-t
-butylbenzoic acid, phthalic anhydride, hexahydrophthalic acid, tetrahydrophthalic acid, phthalic acid, tetrachlorophthalic acid, hexachlorophthalic acid, tetrabromophthalic acid, trimellitic acid, "hymic acid", (anhydrous) succinic acid, (anhydrous) maleic acid,
(anhydrous) one or more carboxylic acids such as itaconic acid, fumaric acid, adipic acid, sebacic acid or oxalic acid in a conventional manner, and if necessary, "Carduura E" (product of Ciel Co., Ltd.) Monoepoxy compounds such as glycidyl esters of fatty acids such as "Epicron 200, 400", "Epicoat"
828, 1001" or diisocyanates such as tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate or 4,4'-methylenebis(cyclohexyl isocyanate), each of these diisocyanates and the above polyhydric alcohols, One or more types of polyisocyanates obtained by addition reaction with water or polyisocyanates having an isocyanuric ring obtained by (co)polymerization of diisocyanates, including the polyhydric alcohols and carboxylic acids mentioned above. A suitable product is one obtained by replacing a part of the compound and reacting it by a conventional method. In this case, the alkyd resin should be of a saturated fatty acid or non-drying oil (fatty acid) modified type that does not have copolymerizable unsaturated bonds or has a small amount, or an oil-free alkyd resin that is not modified with oil or fatty acids. For those products, it is necessary to introduce copolymerizable unsaturated bonds that serve as grafting points for other vinyl monomers into the alkyd resin using an unsaturated carboxylic acid such as (anhydrous) maleic acid or fumaric acid. Needless to say, it is. The alkyd resin obtained in this way is used in a range of 0 to 10% by weight, but when used in a large amount exceeding 10% by weight, solvent resistance, stain resistance, etc. are inferior. . Moreover, during polymerization, the carboxyl group in the alkyd resin and the epoxy group in the epoxy group-containing vinyl monomer react with each other, resulting in undesirable problems such as easy gelation. Therefore, the amount of the alkyd resin to be used is within the range described above, with the acid value, oil length, and amount of copolymerizable unsaturated bonds being adjusted so that gelation does not occur due to reactions between these groups. It is preferable to determine the molecular weight by taking into consideration the molecular weight of the alkyd resin and the molecular weight of the resulting modified copolymer (A). Next, typical examples of the aromatic vinyl monomers mentioned above include styrene, α-methylstyrene, pt-butylstyrene, and vinyltoluene, among which styrene is the most preferred in terms of price. . If the aromatic vinyl monomer is used in a large amount exceeding 60% by weight, the resulting coating film will have poor weather resistance and will be unsuitable as an outdoor paint resin. When used, it should be set within 60% by weight depending on the required performance such as gloss, texture, and weather resistance. From the viewpoint of the balance of gloss, texture, leveling properties, and weather resistance, a range of 10 to 50% by weight is preferable. Furthermore, representative vinyl monomers that can be copolymerized with the epoxy group-containing vinyl monomers, aromatic vinyl monomers, and alkyd resins having copolymerizable unsaturated bonds include methyl ( meth)acrylate, ethyl(meth)acrylate, n-propyl(meth)acrylate, i-propyl(meth)acrylate, n-butyl(meth)acrylate, i-butyl(meth)acrylate, t-butyl(meth)acrylate, Such as 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, dibromopropyl (meth)acrylate, tribromophenyl (meth)acrylate or alkoxyalkyl (meth)acrylate various (meth)acrylates; maleic compounds; diesters of unsaturated dicarboxylic acids such as fumaric acid or itaconic acid with monohydric alcohols; Vinyl esters such as "Viscoat BF, BFM, 3F or 3FM" [fluorine-containing acrylic monomer manufactured by Osaka Organic Chemical Co., Ltd.], perfluorocyclohexyl (meth)acrylate, diperfluorocyclohexyl fumarate or N- (per)fluoroalkyl group-containing vinyl esters, vinyl ales, (meth)acrylate such as i-propyl perfluorooctane sulfonamide ethyl (meth)acrylate;
Fluorine-containing compounds such as acrylates or unsaturated carboxylic acid esters; or (meth)acrylonitrile, vinyl chloride, vinylidene chloride,
These are olefins such as vinyl fluoride or vinylidene fluoride. Typical hydroxyl group-containing vinyl monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 3-hydroxypropyl (meth)acrylate. -Hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, di-2-hydroxyethyl fumarate, mono-2-hydroxyethyl-monobutyl fumarate or hydroxyalkyl esters of α,β-ethylenically unsaturated carboxylic acids such as polyethylene glycol mono(meth)acrylate; unsaturated such as (meth)acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid or citraconic acid. Monomers or dicarboxylic acids, α,β-ethylenically unsaturated carboxylic acids such as monoesters of these dicarboxylic acids and monohydric alcohols; α,β-unsaturated carboxylic acid hydroalkyl esters as described above; Adducts with various polycarboxylic acids (anhydrides) and monoglycidyl esters of monohydric carboxylic acids such as "Carduura E", coconut oil fatty acid glycidyl ester or octylic acid glycidyl ester, or butyl glycidyl ether, ethylene oxide or propylene Monoepoxy compounds and adducts such as oxides; or compounds containing methylol groups such as N-methylolated acrylamide, or hydroxyethyl vinyl ether can also be used; however, in the case of monomers containing functional groups such as vinyl monomers containing hydroxyl groups, Of course, it is necessary to determine the amount used so as not to cause gelation, and the hydroxyl group in the hydroxyl group-containing vinyl monomer and the (β-methyl)glycidyl in the (β-methyl)glycidyl (meth)acrylate. The amount should be determined so that gelation does not occur due to reaction with groups. Next, as the cellulose derivative (B) described above,
Any material that is normally used for paints can be used, but the most representative ones include nitrocellulose, cellulose acetate, cellulose acetate propionate,
Cellulose acetate butyrate, methylcellulose, ethylcellulose or benzylcellulose. The cellulose derivative may be used when it is necessary to further improve drying properties, gasoline resistance, adhesion properties, etc., but in that case, the appropriate amount to be used is 40% by weight or less, preferably 30% by weight or less. However, this does not preclude the use of known and commonly used plasticizers such as dibutyl phthalate or dioctyl phthalate, if desired. If the amount used exceeds 40% by weight, stain resistance, water resistance, moisture resistance, etc. will be noticeably reduced, which is not preferable. Further, the above-mentioned ultraviolet absorber (C) is a component used when it is necessary to further increase the durability of the composition of the present invention, and may be added and mixed each time, but in that case, the above-mentioned It may be used in an amount of 0 to 10% based on the total weight of the modified copolymer (A) and cellulose derivative (B). If the amount used exceeds 10%, the effect is great, but the water resistance often decreases and it becomes disadvantageous in terms of cost. Typical UV absorbers (C) are:
Benzophenone, 2,4-dihydrobenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'- Dimethoxybenzophenone, 2,2'-dihydroxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4-methoxy-5- Sulfobenzophenone, 5-chloro-2
-Hydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-
(2-hydroxy-3-methyl-acryloxyisopropoxybenzophenone; 2-(2'-hydroxy-5'-methyl-phenyl)-benzotriazole, 2-(2-hydroxy-3,5-di-t) −
amyl-phenyl)-2H-benzotriazole,
2-(2'-hydroxy-3',5'-di-t-butyl-
phenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butyl-5'-methyl-
phenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-t-butyl-phenyl)-
5-chloro-benzotriazole, 2-(2'-hydroxy-3',5'-di-t-isoamyl-phenyl)benzotriazole, (2-hydroxy-5
-t-butylphenyl)benzotriazole; phenyl salicylate, 4-t-butyl-phenyl salicylate, p-octyl-phenyl salicylate; ethyl-2-cyano-3,3'-diphenyl-acrylate, 2-ethylhexyl-2 -cyano-3,3'-diphenyl-acrylate; hydroxy-5-methoxy-acetophenone, 2-hydroxy-naphthophenone; 2-ethoxyethyl-
p-methoxycinnamate; nickel-bisoctylphenyl sulfide; 4-benzoyloxy-2,2,6,6-tetramethylpiperidine,
These include bis-(2,2,6,6-tetramethyl-4-piperidyl) sebacate or "Tinuvin 292" (product of Ciba Geigy), and these may be used alone or in combination of two or more. In order to further increase the effectiveness, "Sumilizer BHT" [product of Sumitomo Chemical Co., Ltd.], "Seanox BCS" [product of Shiraishi Calcium Co., Ltd.], "Irganox 1010 or 1076" (product of Ciba Geigy), A well-known and commonly used antioxidant such as "Noklyzer TNP" (manufactured by Ouchi Shinko Co., Ltd.) or "Antioxidant KB" (manufactured by Bayer AG, West Germany) can also be used in combination. Next, the dryer (D) described above is usually
Any material commonly used for paints may be used, but the most representative ones include cobalt, vanadium, manganese, cerium, lead, iron, calcium, zinc, zirconium,
naphthenates, octylates or resinates such as cerium, nickel or tin;
The amount to be used may be appropriately determined from conventional amounts depending on the type of dryer, the combination of each component, the required performance, etc. At this time, a small amount of an organic peroxide such as benzoyl peroxide, methyl ethyl ketone peroxide or 5-butyl perbenzoate may be used in combination to enhance the effectiveness of the dryer. In addition, known and commonly used paint additives such as pigment dispersants or leveling agents can also be used in combination. Furthermore, typical polyisocyanates (E) mentioned above include tolylene diisocyanate,
Aromatic diisocyanates such as xylylene diisocyanate or diphenylmethane diisocyanate; aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate or trimethylhexamethylene diisocyanate; or isophorone diisocyanate, methylcyclohexane-2,4-(or -2,6-) ) Diisocyanates such as diisocyanate, cycloaliphatic diisocyanates such as 4,4'-methylenebis(cyclohexyl isocyanate) or 1,3-di(isocyanatemethyl)cyclohexane, or each of these diisocyanates and the polyhydric alcohols and isocyanates. low-molecular-weight polyester resins (including oil-modified types) having functional groups that react with groups, acrylic copolymers (including those containing styrene as a comonomer component), or adducts with water, etc. Furthermore, there are also biuret bodies and (co)polymers (including oligomers) of the various diisocyanates mentioned above. Furthermore, polyisocyanates blocked with known and commonly used blocking agents such as methyl ethyl ketone oxime or caprolactam can also be used depending on the material and curing conditions. By the way, when using the polyisocyanate, aromatic diisocyanates and their derivatives, which yellow or crack when exposed to ultraviolet rays, are not suitable for outdoor topcoats that require weather resistance. Yes, it is mainly used as a top coat for indoor applications where weather resistance is not required, or as an undercoat paint such as Primer Surfer.
Therefore, in such cases, aliphatic diisocyanates, alicyclic diisocyanates, or various derivatives thereof, which have good weather resistance, may be used as top coats for outdoor use. The usage fee for the polyisocyanate is as follows:
A suitable equivalent ratio range is OH/NCO=1/0.1 to 1/1.2. On the other hand, in the case of materials with relatively good heat resistance such as FRP, FRTP, or PBT, amino resins can be used as long as the curing conditions are met.
Typical such amino resins include those obtained by the condensation reaction of urea, guanamines, or various triazines such as melamine with aldehydes. , n-butanol or iso-butanol are preferred from the viewpoint of compatibility or solubility. The amount of the amino resin used is 60 to 100% by weight of the component (A) and 40 to 0% by weight of the component (B).
From the viewpoint of physical properties, the weight ratio of the amino resin to the mixture consisting of % by weight of the former mixture/latter resin is preferably within the range of 70 to 95/5 to 30. Further, in this case, in order to lower the baking temperature and accelerate curing, a conventionally known curing catalyst such as phosphoric acid or p-toluenesulfonic acid may be used in a conventional amount. Furthermore, when using the amino resin, small amounts of blocked isocyanates such as those listed above may also be used. In preparing the composition of the present invention, first, the epoxy group-containing vinyl copolymer (a-1) is
Usually, after preparing by solution polymerization, this copolymer (a-1) is then added to the drying oil fatty acid (a-1).
2) to obtain the target fatty acid-modified vinyl copolymer (A), but in this copolymerization reaction, which can be called the first stage reaction, the copolymer (a- The polymer conversion rate to 1) is
Normally, after securing 95% or more, the drying oil fatty acid (a-2) is added to carry out the addition reaction, which can be called the second stage reaction, without waiting for the completion of the copolymerization reaction. This is advantageous because it allows you to move forward. In addition, the reaction temperature is not particularly limited, and during the copolymerization reaction, as long as it is at a temperature suitable for polymerizing each component compound as mentioned above, that is, a temperature in the range of 50 to 140°C, which is usually adopted. often,
On the other hand, during the addition reaction, any temperature suitable for the addition of each reaction component as listed above, that is, a temperature in the range of 110 to 180°C, is sufficient. In particular, during the addition reaction, the temperature may be high to promote this reaction. This is also advantageous since it can also be done. Furthermore, in order to promote the addition reaction, a catalyst for the ring-opening reaction of epoxy groups may be used. In that case, any known and commonly used catalyst can be used, but typical examples include triethylamine, triethylamine, These include tertiary amines such as diethylenetriamine or imidazole, BF ₃ complexes, or acids such as phosphoric acid or sulfuric acid. Furthermore, as the polymerization initiator used in the polymerization, any known and commonly used initiator can be used, but among them, particularly representative ones include azobisisobutyronitrile and benzoyl peroxide. , t-butyl perbenzoate, t-butyl peroctate, di-t-butyl peroxide. Known and commonly used solvents can be used, but the most representative ones include aromatic solvents such as toluene or xylene, ester solvents such as ethyl acetate, butyl acetate or cellosolve acetate, and alcoholic solvents such as methanol or butanol. or ketones such as methyl ethyl ketone or methyl isobutyl ketone, and aliphatic or alicyclic solvents such as hexane, heptane, cyclohexane, methyl cyclohexane, petroleum naphtha or mineral spirits can also be used, especially Aliphatic and alicyclic solvents are indispensable in order to obtain paints that do not easily attack the surface of plastics. The types, combinations, and amounts of such solvents can be appropriately determined in consideration of the amount of the drying oil fatty acid used, the amount of the vinyl moiety in the epoxy group-containing vinyl copolymer, and the like. The thus obtained drying oil fatty acid-modified vinyl copolymer is in the form of a drying oil fatty acid-modified vinyl copolymer grafted with an alkyd resin, and therefore has good pigment wettability of the alkyd resin. This gives an excellent gloss, and because of this unique structure, it has the advantage of being able to be air-cured by adding a dryer. In addition, in the present invention, during the preparation of the epoxy group-containing vinyl copolymer, that is, during radical polymerization, the alkyd resin is not only radically polymerized, but also the carboxyl group in the alkyl resin within the specified amount range is converted into the epoxy group. As a result of the addition reaction with the epoxy group in the vinyl monomer contained, the resulting modified copolymer (A) has a wide molecular weight distribution, and has excellent pigment dispersibility.
There is also the advantage of being able to obtain a product that has features such as a feeling of texture and excellent adhesion to the base material. The composition of the present invention meets the various needs in this industry as described above. That is, the resin composition for coating plastics of the present invention can be said to be the third type of coating material for coating plastics, and is an oxidative polymerization based on the drying oil fatty acid residue contained in the modified copolymer (A). The crosslinking reaction between the hydroxyl groups slightly present in the modified copolymer (A) and the polyisocyanate (E) blended therewith, and the (parallel) crosslinking reaction of both of them. It is a unique composition in that a type of crosslinking reaction can be applied to one type of modified vinyl copolymer (A) as desired, and a coating film with excellent performance can be obtained through such crosslinking reaction. It can be said that. Materials to which the composition of the present invention can be applied include ABS, "Noryl", polycarbonate, melamine resin, polystyrene, urea resin,
polyester resin, polypropylene or RIM,
From those composed of a single component such as urethane, to mixed or composite systems composed of multi-component systems (including various polymer alloys), or so-called so-called such as FRT, FRTP or FR-RIM. Can be used in a wide range of materials, including composite materials. Since a drying oil fatty acid is introduced into the modified vinyl copolymer (A) as an essential component of the composition of the present invention, the composition of the present invention as a whole is suitable for use in acrylic polyols used in urethane systems. Since it is easily dissolved in solvents (weak solvents) that have a weaker solubility than other solvents, it has the advantage of being able to use large amounts of weak solvents, making it possible to create paints for plastics that do not attack the surface of the material to be coated. can give. Furthermore, by using a unique method of adding a drying oil fatty acid to an epoxy group-containing vinyl copolymer, the modified copolymer, which is an essential component of the composition of the present invention, can be produced.
(A) also has a hydroxyl group, and in addition, in the present invention, in addition to the epoxy group-containing vinyl monomer, a hydroxyl group-containing vinyl monomer can also be used in combination. Furthermore, it is possible to contain hydroxyl groups, and as a result, by incorporating polyisocyanate (E), a method of urethane crosslinking and curing can be adopted, and furthermore, oxidative polymerization and crosslinking curing with a dryer (D) and this urethane crosslinking can be performed. It has the advantage of being able to use a method of curing that involves two crosslinking reactions: curing and curing. Next, the present invention will be specifically explained with reference to Reference Examples, Examples, and Comparative Examples. In the following, all parts and percentages are based on weight unless otherwise specified. Reference Example 1 [Preparation example of modified vinyl copolymer (A)] In a four-necked flask equipped with a thermometer, reflux condenser, stirrer, and nitrogen gas inlet, 800 g of xylene was added.
1 part, 71 parts of "Betucosol P-470-70" [long oil alkyd resin manufactured by Dainippon Ink and Chemicals Co., Ltd.] and 2 parts of di-t-butyl peroxide (hereinafter abbreviated as DTBPO). After charging, the temperature was raised to 125℃, and when the temperature reached the same temperature, 400 parts of styrene (St), 300 parts of methyl methacrylate (MMA), 55 parts of acrylonitrile (AN), and 125 parts of glycidyl methacrylate (GMA) were added. , a mixture consisting of 70 parts of ethyl acrylate (EA), 10 parts of azobisisobutyronitrile (AIBN), 7 parts of t-butyl peroctate (TBPO) and 4 parts of t-butyl perbenzoate (TBPB). was added dropwise over a period of 5 hours, and kept at the same temperature for 5 hours after the dropwise addition, until the non-volatile content (NV) reached 53.9%.
When 0.2 parts of methylimidazole (2MIZ) was added and the addition reaction between glycidyl and carboxyl groups was carried out at the same temperature, the NV was 60.3% after 13 hours.
The viscosity (Gardner; the same applies hereafter) is Z ₆ , and the acid value is
A solution of a fatty acid-modified vinyl copolymer named 2.6 was obtained, and 400 parts of xylene was added to this solution to convert NV.
Adjusted to 50%. The resin solution thus obtained had an NV of 50.1%,
Viscosity is Y-Z, number of colors (Gardner; same below)
is 5 to 6, and the number average molecular weight by gel permeation chromatography (GPC) (hereinafter referred to as
Abbreviated as Mn. ) was a clear solution of 8300. Hereinafter, this will be abbreviated as modified copolymer (A-1). Reference example 2 (same as above) In the same way as reference example 1, add “Betucosol” to the flask.
200 parts of "1343" (medium oil alkyd resin manufactured by the same company),
1300 parts of turpentine and 3 parts of DTBPO were charged and heated to 120℃, and at the same temperature 300 parts of St and 3 parts of MMA were added.
A mixture of 300 parts of GMA, 200 parts of GMA, 100 parts of n-butyl acrylate (BA), 15 parts of AIBN, 10 parts of TBPO, and 2 parts of TBPB was added dropwise over 5 hours, and the mixture was kept at the same temperature for another 12 hours. Then, the polymerization was continued and the NV was 42.0%. At this stage, a white wax-like vinyl copolymer was obtained which was not dissolved in the turpentine. Next, 100 parts of cottonseed oil fatty acid and 300 parts of dehydrated castor oil fatty acid were added to this copolymer and heated at 150°C.
After reacting until the acid value reached approximately 1, NV
A transparent resin solution was obtained with a viscosity of Z-Z ₁ , an acid value of 1.1, a color number of 1 to 2, and a length of 7200. Hereinafter, this will be referred to as a modified copolymer (A-
It is abbreviated as 2). Reference example 3 (same as above) In the same way as reference example 1, add 1200 g of xylene to the flask.
part, 29 parts of "Betsukosol P-470-70",
After charging 4 parts of DTBPO and raising the temperature to 125℃, at the same temperature, 200 parts of St, 230 parts of MMA,
125 parts of GMA, 100 parts of BA, 225 parts of n-butyl methacrylate (BMA), 100 parts of 2-hydroxyethyl methacrylate (2-HEMA),
A mixture consisting of 5 parts of AIBN, 3 parts of TBPO, and 5 parts of TBPB was added dropwise over 5 hours, and the polymerization was continued at the same temperature until the NV reached 44%. and 100% of safflower oil fatty acids
part and 0.02 part of BF ₃ etherate to give an acid value of 1
When the reaction was carried out to a point near the
Z ₄ , number of colors is 2, acid value is 1.8, hydroxyl value is 35
A clear resin solution with a weight of 14,000 was obtained. Hereinafter, this will be abbreviated as modified copolymer (A-3). Reference example 4 (same as above) In a flask similar to reference example 1, add 1075 xylene.
1 part, 125 parts of "Betsukosol J-571" (long oil alkyd resin made by the same company) and 4 parts of DTBPO were heated to 125℃, and at the same temperature, St.
400 copies, BMA 200 copies, GMA 50 copies, 2-
100 copies of HEMA, 50 copies of AN, 100 copies of BA,
A mixture consisting of 18 parts of TBPO and 4 parts of TBPB was added dropwise over 4 hours, and the polymerization was continued for 12 hours.
The temperature was raised to 150°C, 100 parts of dehydrated castor oil fatty acid was added, and the addition reaction was continued until the acid value reached around 1.
NV is 49.3%, viscosity is Z ₁ , acid value is 1.2, hydroxyl value is
A transparent resin solution with a color number of 5 to 6 and 11,000 was obtained. Hereinafter, this will be referred to as a modified copolymer (A
-4). Reference Example 5 (Same as above) 545 parts of isophthalic acid, 248 parts of adipic acid, and 362 parts of neopentyl glycol were placed in the same flask as in Reference Example 1, except that a water separator was attached instead of the reflux condenser. , 276 parts of trimethylolpropane and 18 parts of fumaric acid were charged and reacted at 180°C for 3 hours in a N ₂ stream.Then, the temperature was raised to 220°C over 2 hours to continue the reaction, and the solid content was reduced at the same temperature. After cooling down when the acid value reaches approximately 6, xylene/butyl acetate = 50/50 (weight ratio)
By diluting NV to 60% with a mixed solvent of . Then 34 parts of this resin solution and 1200 parts of xylene
1 part and 5 parts of DTBPO were placed in a flask similar to Reference Example 1 and heated to 125°C, and when the temperature reached the same temperature, 300 parts of St, 30 parts of MMA, 100 parts of t-butyl methacrylate (t-BMA), GMA 125 division,
285 copies of BMA, 40 copies of 2-HEMA, 100 copies of BA,
A mixture consisting of 8 parts of AIBN, 3 parts of TBPO, and 5 parts of TBPB was added dropwise over 5 hours, and the polymerization was continued at the same temperature until the NV reached 44%. and 0.04 parts of BF ₃ etherate to give an acid value of 1
When the reaction reached the vicinity, NV was 50.1% and viscosity was Y.
-Z, acid value is 1.9, color number is 2, hydroxyl value is 25,
A clear resin solution of 12,000 ml was obtained. Hereinafter, this will be abbreviated as modified copolymer (A-5). Reference Example 6 (Same as above) NV was prepared in the same manner as Reference Example 2 except that the same amount of t-BMA was used instead of St.
is 50.6%, viscosity is Y, color number is 2, acid value is 1.5,
A clear resin solution of Katsuga 7100 was obtained. Hereinafter, this will be abbreviated as modified copolymer (A-6). Reference example 7 (same as above) Instead of 200 copies of St, 100 copies of t-BMA, 50
Reference Example 3 except that 1 part of Ni-propyl perfluorooctane sulfonamide ethyl acrylate and 50 parts of "Viscoat 8F" [octafluorobutyl methacrylate manufactured by Osaka Organic Chemical Co., Ltd.] were used. Similarly, NV was 49.8%,
Viscosity is Z ₃ , color number is 2, acid value is 1.7, hydroxyl value is 35
A clear resin solution with a weight of 14,000 was obtained.
Hereinafter, this will be abbreviated as modified copolymer (A-7). Reference example 8 (same as above) In a flask similar to reference example 1, add xylene 818
1 part and 2 parts of DTBPO were charged and the temperature was raised to 125°C.
After reaching the same temperature, the same procedure as in Reference Example 1 was performed except that the amount of BA was changed to 120 parts, and NV was
When the concentration reached 54.1%, 50 parts of linseed oil fatty acid, 150 parts of soybean oil fatty acid and 0.2 part of 2-MIZ were added and the addition reaction was continued until the acid value reached around 2.5. Next, add 400 parts of xylene to NV
When adjusted to 50%, NV was 49.8%, viscosity was Y,
A transparent resin solution with a color number of 5 to 6, an acid value of 2.2, and a weight of 8000 was obtained. Hereinafter, this will be abbreviated as modified copolymer (A-8). Reference example 9 (same as above) Abstains from the use of "Betucosol 1343", uses 1400 parts of turpentine, and NV is 41.8%
The procedure was carried out in the same manner as in Reference Example 2, except that a white wax-like vinyl copolymer was obtained. NV was 50.1%, viscosity was Y-Z, and acid value
A transparent resin solution with a color number of 1.0, a color number of 1 to 2, and a size of 7000 was obtained. Hereinafter, this will be abbreviated as modified copolymer (A-9). Reference example 10 (same as above) Oil-free oil containing 3.4 parts of polymerizable unsaturated bonds
Instead of alkyd resin solution, 20 parts BMA and 14
of xylene, and the initial charge in the flask should be increased from 1200 parts to 1214 parts, and added dropwise.
The same procedure as Reference Example 5 was carried out except that the amount of BMA was changed from 285 parts to 305 parts. NV was 49.9%, viscosity was X-Y ₂ , acid value was 1.8, color number was 1, and hydroxyl value was 25. ,
A clear resin solution with a weight of 12000 was obtained. Hereinafter, this will be abbreviated as modified copolymer (A-10). Reference example 11 (same as above) Instead of 200 parts of St, the same amount of t-BMA, 29
20 parts of BMA and 9 parts of xylene were used in place of 1 part of "Betucosol P-470-70", and both of these vinyl monomers and solvents were added dropwise rather than as an initial charge. The procedure was the same as in Reference Example ₃ , except that it was changed to be used as a minute. A resin solution was obtained. Hereinafter, this will be abbreviated as modified copolymer (A-11). Examples 1 to 30 and Comparative Examples 1 and 2 Modified copolymers obtained in Reference Examples 1 to 11 (A-
1) to (A-11), and Table 1 and 2.
"Tiepeke CR-93" [Rutile type titanium oxide manufactured by Ishihara Sangyo Co., Ltd.] as shown in the table, 6% cobalt naphthenate / 24% lead naphthenate = 50/50 (weight ratio)
White enamel paints were also prepared using dryers, cellulose derivatives, UV absorbers and/or polyisocyanates. However, Comparative Examples 1 and 2 are examples in which commercially available paints for acrylic urethane plastics were used. In addition, these cellulose derivatives include 1/4s nitrocellulose (1/4″NC) and
"CAB-551-0.2" [cellulose acetate butyrate (CAB) manufactured by Eastman Kodatsu, USA] was used, and as the ultraviolet absorber "Tinuvin 292" / "Tinuvin 900" = 50/50 (weight (ratio) (both ``Tinuvin'' are products of Ciba-Geigy, West Germany) were used, and the polyisocyanate was ``Burnock DN-950'' [hexamethylene diisocyanate-based polyisocyanate manufactured by Dainippon Ink & Chemicals Co., Ltd.]. , "Coronate EH"
[Hexamethylene diisocyanate polyisocyanate manufactured by Nippon Polyurethane Industry Co., Ltd.] was used, but in Examples 2 and 22, 2 parts of a plasticizer called butylbenzyl phthalate was also used,
In addition, all cellulose derivatives were used as 40% methyl ethyl ketone solutions. To make the white enamel into a paint, 100 parts of the modified copolymer (A), which is the main component of the paint varnish, and a predetermined amount of "Tiepeke CR-93" were added, as well as 30 parts of xylene and 200 parts of glass beads. and kneaded it in a sand mill for 90 minutes.35
% PWC. Xylene/Solbetsuso 100/acetic acid i- is used as a diluting thinner for painting.
A mixed solvent of butyl = 80/10/10 (weight ratio) was used. Next, the painting was done by spray painting, using ABS board, "Noryl" board or glass board as the base material, and forced drying at 60℃ for 20 minutes as the curing condition. Membrane performance tests were conducted after the membrane was allowed to stand for 7 days after forced drying. Of these materials, we tested the gloss, pencil hardness, gasoline resistance, and drying properties of the physical properties of the glass coating film, and the ABS board was used for the "adhesion" test of the physical properties of the coating film. In addition, the "Noryl" board was tested for the "adhesion" of the physical properties of the coating film and the effect of the resin solution on the base material. It was used for the visual test. Among the test items, the ``adhesion'' test involves making a cross cut, then peeling off the cellophane tape, and the ``gasoline resistance'' test involves applying two coats of regular gasoline to the tape. It is a comprehensive evaluation based on visual judgment such as the degree of softening and discoloration of the paint film after soaking for a period of time, and the presence or absence of blisters.
It shows the gloss retention rate (%) when exposed for hours and when exposed outdoors for 2 years in Miyazaki City, and the "drying" test is based on dryness to the touch (unit: minutes). , 4 on the coating surface
Two layers of gauze were placed on top of each other, and a 100g weight was placed on top of the gauze for 1 minute, and the gauze marks were then visually judged.
The evaluation criteria for this dryness were as follows. ◎... No gauze marks at all ○... Some gauze marks △... Quite a few gauze marks ×... Significant gauze marks The results of each example and comparison column are as follows:
Examples 21 to 30 and Comparative Examples 1 and 2 are shown separately in Table 2, but only comparison columns 1 and 2 are shown in each table.

【table】

【table】

【table】

[Table] Examples 31 to 40 and Comparative Examples 3 to 6 First, "Acrydik 44-198" [acrylic polyol manufactured by Dainippon Ink and Chemicals Co., Ltd.] and "Burnock DN-950" (isocyanate compound manufactured by the same company) ) and OH/NCO = 1/1 equivalence ratio, and colored blue with cyanine blue,
Also, ``Alpaste 1109AM'' [aluminum paste manufactured by Toyo Aluminum Co., Ltd.] was added to give 10%
Prepare base paint as PWC, then apply this
After applying a metallic base coat to the ABS board using air spray, a top clear was prepared using the proportions shown in Table 3.
i-Butyl acetate = 80/10/10 (weight ratio) was used. ], a clear coat was applied by air spray, and after setting for 1 hour, forced drying was performed at 60°C for 20 minutes to obtain a cured coating. In other words, each of the Examples and Comparative Examples in this series relates to a so-called "two-coat, one-bake system." However, after being allowed to stand for 7 days after this forced drying, the performance of each coating film was evaluated. Of each test item, gloss, hardness, Erichsen,
The impact resistance, gasoline resistance and weather resistance are as described above, but the removability and finished appearance are as follows. In other words, "removability" is determined by making crosscuts, peeling off with cellophane tape, and checking the interlayer adhesion between the top coat and base coat. The following evaluation criteria were used. ◎…No abnormalities ×…Peeling On the other hand, “finished appearance” shows metal unevenness on the painted surface,
Frontal appearance, sheer appearance, and fleshiness were comprehensively judged by visual inspection, and were based on the following evaluation criteria. ◎...Excellent○...Good△...Average ×...Poor The above results are summarized in Table 3. Comparative Examples 3, 4, 5 and 6 are examples in which commercially available asuryl urethane paints for plastics were used.

[Table] Examples 41 to 47 and Comparative Examples 7 to 10 Each of the Examples and Comparative Examples in this series is for examining pigment dispersibility. Modified copolymer (A-1) to give a PWC of
Weigh each pigment against 100 parts of ~(A-11),
Further, 30 parts of xylene and 200 parts of glass beads were separately added and kneaded for 2 hours in a sand mill, and then each kneaded enamel base was mixed with the solid content of the modified copolymer used therein. Various paints were prepared by adding 4% of a mixture of 6% cobalt naphthenate/24% lead naphthenate = 50/50 (weight ratio). White..."Typaque CR-93", PWC: 35% Black..."Royal Spectra Mark" (carbon black manufactured by Columbia Carbon, USA), PWC: 30% Red..."Fast Gen Super Red BN"
[Quinacridone pigment manufactured by Dainippon Ink and Chemicals Co., Ltd.] PWC: 10% Green... "Fast Gen Green S" (cyanine green manufactured by the same company), PWC: 10% Next, pigment dispersibility of each paint was determined. First, the evaluation criteria for the thixotropy of the paint and the presence or absence of pigment aggregation are as follows. ◎...No abnormality ×...There is thixotropy or aggregation, poor dispersibility Next, the color difference (△E) of the four-color mixture spray/flow coating is white/black/red/green = 100/5/5/5 A four-color mixed paint prepared by mixing the above-mentioned enamel varnishes in the following ratio (weight ratio) and further adding a mixture of 6% cobalt naphthenate/24% lead naphthenate = 50/50 (weight ratio). Color difference (△E) for the coated plates that were first spray-painted on each tin plate separately, then allowed to dry to the touch, and then flow-painted.
It can be said that the smaller this value is, the smaller the pigment is, and therefore the better the pigment dispersibility. The above results are summarized in Table 4. Thixotropy and pigment aggregation were not observed when titanium oxide ("Tiepeque CR-93") was used in both Examples and Comparative Examples. Not shown in the table.

[Table] Examples 48 to 53 Furthermore, Examples 1 to 30 were prepared using FRP board as the base material and blocked polyisocyanate or amino resin as the crosslinking agent component, and with the paint formulation shown in Table 5. A coating film made into a paint and painted under similar paint conditions and painting conditions was used as "Super Betsucomin L-117-60" [Dainippon Ink & Chemicals Co., Ltd.]
Butylated melamine resin produced by Manufacturer; non-volatile content = 60%] used alone, and this and "Burnok 16-419"
[Hexamethylene diisocyanate type blocked polyisocyanate manufactured by the same company; non-volatile content = 72
%, recycled isocyanate content = 5%], 140℃ x 30 minutes, "Barnock 16-419"
In the case of a single use system, a cured coating film was obtained by baking under the baking conditions of 130°C for 30 minutes. Next, the performance evaluation of each coating film thus obtained is summarized in the same table.

【table】

Claims (1)

[Claims] 1 (A) 5 to 25% by weight of an epoxy group-containing vinyl monomer, 0 to 60% by weight of an aromatic vinyl monomer,
Copolymerizing 0 to 10% by weight of an alkyd resin having a copolymerizable unsaturated bond and 5 to 95% by weight of another vinyl monomer copolymerizable with these,
Next, a drying oil fatty acid (a-2) having an iodine value of 100 to 200 is added to 100 parts by weight of the epoxy group-containing vinyl copolymer (a-1) thus obtained.
(B) 60 to 100% by weight of a modified vinyl copolymer obtained by adding 5 to 60 parts by weight of a cellulose derivative, and 0 to 40% by weight of (B) a cellulose derivative; based on the weight of (C) 0 to 10% by weight of an ultraviolet absorber, or also (D) a dryer and/or (E) a polyisocyanate or an amino resin. A resin composition for coating plastics that has excellent drying properties and texture, and does not easily penetrate the surface of the material to be coated.