JPH0354695B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to coating agents.
More specifically, the present invention relates to a coating agent suitable for coating polyolefin molded articles. Polyolefins such as propylene-based polymers have advantages such as low cost, light weight, excellent solvent resistance, and good processability, and their molded products have come to be widely used in automobile parts and cabinets of electrical appliances. . In recent years, there have been many requests for secondary processing such as painting, adhesion, and printing in order to increase the added value of polyolefin molded products. However, since polyolefin has poor polarity, it is difficult for various coating materials to adhere to it. For this reason, a technique is used in which a chlorinated polyolefin such as chlorinated polypropylene is used alone or in combination with other resins, and a polyolefin molded product is subjected to surface treatment with a solution of the chlorinated polyolefin. However, the adhesion to both the polyolefin base material and the top coat and the uniformity of the solution were not satisfactory. As a result of extensive studies, the present inventors have discovered that a composition comprising a polybutadiene glycol urethane resin and a chlorinated hydrocarbon resin can solve the above problems, and have arrived at the present invention. That is, the present invention is a coating agent (hereinafter also referred to as the coating agent of the present invention) suitable for coating a polyolefin molded product made of a polybutadiene glycol urethane resin (a) and a chlorinated hydrocarbon resin (b). In the present invention, examples of the polybutadiene glycol-based urethane resin (a) include polyols containing usually 50% by weight or more of polybutadiene glycol and, if necessary, resins containing other active hydrogen-containing compound components and polyisocyanate components. Examples of the polybutadiene glycol include hydroxyl group-terminated polybutadiene oligomers and polymers. Specifically, polybutadiene glycols include those having a 1.2-vinyl structure, those having a 1.2-vinyl structure and a 1.4-trans structure, and those having a 1.4-trans structure.
The ratio of 1.2-vinyl structure and 1.4-trans structure can be changed in various ways, for example, by changing the molar ratio.
It is 100:0 to 0:100. Polybutadiene glycols also include homopolymers and copolymers (styrene-butadiene copolymers, acrylonitrile-butadiene copolymers, etc.). Its average molecular weight is usually 500~10000, preferably 1000~
5000. When the average molecular weight is less than 500, the coating agent of the present invention becomes brittle and its adhesion to polyolefin molded articles also decreases. The average molecular weight
If it exceeds 10,000, the paint film becomes sticky. Specifically, polybutadiene glycol is as follows. The products represented by formula (1) include the NISSO-PBG series (Nippon Soda products), specifically G-1000,
Examples include G-2000 and G-3000. Products represented by formulas (2) and (3) include Poly Bd (U.S.
ARCO product), specifically Poly Bd R-45M,
Examples include R-45HT, CS-15, and CN-15. The average molecular weight of these products is 1000 to 5000, and the average number of functional groups is 1.5 to 2.5. As a method for producing polybutadiene glycol, for example, butadiene is converted into β'-azobis(β-cyano).
- Radical polymerization using a catalyst containing a hydroxyl group such as n-propanol, anionic polymerization using an alkali metal such as sodium or lithium, or a complex of an alkali metal and a polycyclic aromatic compound as a catalyst, followed by alkylene oxide, epichlorohydrin, etc. Examples include methods for reacting. Polybutadiene glycol may also be a hydrogenated product thereof (the polybutadiene glycol in the present invention also includes a hydrogenated product). The hydrogenation rate is, for example, 20 to 100%. Hydrogenated products of polybutadiene glycol are produced by reacting hydrogen with metal catalysts such as nickel, cobalt, platinum, palladium, and ruthenium under normal pressure or high pressure (for example, hydrogen pressure of 10 to 100 kg/cm ² ) at 20 to 200°C. It can be easily obtained by Hydrogenation may be carried out in the presence of an organic solvent such as hexane, heptane, cyclohexane, etc., if necessary. In addition to polybutadiene glycol, other polyols such as other high-molecular diols and low-molecular polyols can be used as the polyols, if necessary. Other polymeric diols have a molecular weight of 500 to 5000.
Examples include polyether diols, polyester diols, polyether ester diols, polymer diols obtained by polymerizing monomers such as acrylonitrile, styrene, and vinyl chloride in these diols, and mixtures of two or more of these diols. Polyether diols include those obtained by polymerizing or copolymerizing (block or random) alkylene oxides (ethylene oxide, propylene oxide, butylene oxide, etc.) and cyclic ethers (tetrahydrofuran, etc.), such as polyethylene glycol, polypropylene glycol, polyethylene-propylene. (Block or random) glycols, polyoxytetramethylene glycols, polyoxyhexamethylene glycols, polyoxyoctamethylene glycols and mixtures of two or more thereof. Examples of polyester diols include dicarboxylic acids (adipic acid, succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, etc.) and glycols [ethylene glycol, propylene glycol, 1.4-butanediol, 1.6-hexanediol, 1.8- Octamethylene diol, neopentyl glycol, bishydroxymethylcyclohexane, bishydroxyethylbenzene, alkyl dialkanolamine, m-xylylene glycol, 1.4-bis(2-hydroxyethoxy)
Benzene, 4,4-bis(2-hydroxyethoxy)
-diphenylpropane, etc.], such as polyethylene adipate,
Examples include polybutylene adipate, polyhexamethylene adipate, polyethylene/propylene adipate; polylactone diols such as polycaprolactone diol; and mixtures of two or more thereof. Examples of polyether ester diols include ether group-containing diols (the above-mentioned polyether diols, diethylene glycol, toluethylene glycol, dipropylene glycol, etc.)
or those obtained by reacting mixtures of these with other glycols with the dicarboxylic acids or with dicarboxylic acid anhydrides (phthalic anhydride, maleic anhydride, etc.) and alkylene oxides, such as poly(polyoxytetramethylene). ) adipate. The average molecular weight of polymeric diols (based on hydroxyl value measurement) is usually 500~
5000, preferably 700-4000, particularly preferably
It is 1000-3500. In addition to high-molecular diols, low-molecular diols can also be used in combination, if necessary. Examples of low-molecular diols include the glycols mentioned as raw materials for the polyester diols and their low-mole alkylene oxide adducts (molecular weight less than 500). Furthermore, trifunctional or higher functional low molecular weight polyols can also be used in combination for the purpose of improving physical properties. Examples of the low-molecular polyol include glycerin, trimethylolpropane, and pentaerythritol. Among other polyols, preferred are low-molecular diols [especially ethylene glycol, propylene glycol, 1,4-butanediol, 1,4-bis(2-hydroxyethoxy)benzene, 4,4'-bis(2-hydroxyethoxy)-diphenylpropane] ] and trifunctional or higher functional low molecular weight polyols (especially trimethylolpropane). Other active hydrogen-containing compounds that may be used as necessary include low molecular weight diamines such as aliphatic diamines (ethylene diamine, 1,2-propylene diamine,
hexamethylene diamine, 2.2.4-trimethylhexamethylene diamine, etc.), alicyclic diamines (1-amino-3-aminomethyl-3.5.5-trimethylcyclohexane, 4.4'-diaminodicyclohexylmethane, isopropylidenecyclohexyl-4.4'- diamines, 1,4-diaminocyclohexane, etc.), aromatic diamines (xylylene diamine,
4,4'-diaminodiphenylmethane, etc.), heterocyclic amines (piperazine, etc.), and mixtures of two or more of these. Preferred among these are 4,4'diaminodicyclohexylmethane and 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane. In the present invention, the content of polybutadiene glycol in the polyol component is 50% by weight or more, preferably 65% by weight or more. If the polybutadiene glycol content is less than 50% by weight, the uniformity of the solution prepared by dissolving the coating agent of the present invention in an organic solvent and the adhesion to the polyolefin substrate will decrease. The amount of low molecular weight diol is usually 50% by weight based on the high molecular weight diol including polybutadiene glycol.
The content is preferably 5 to 30% by weight. The amount of the trifunctional or higher-functional low molecular weight polyol is usually 3% by weight or less, preferably 0.3 to 2% by weight, based on the polymer diol containing polybutadiene glycol. The amount of low molecular weight diamine is usually 20% by weight or less, preferably 0.3 to 10% by weight, based on the total active hydrogen-containing compound. In the polyisocyanate component, the polyisocyanate is an aliphatic diisocyanate having 2 to 12 carbon atoms (excluding carbon in the NCO group), or an aliphatic diisocyanate having 4 carbon atoms.
~15 alicyclic diisocyanates, araliphatic diisocyanates having 8 to 12 carbon atoms, aromatic diisocyanates having 6 to 20 carbon atoms, modified products of these diisocyanates (carbodiimide, uretdione, uretimine group-containing modified products, etc.): and these Examples include mixtures of two or more of the following. Aliphatic diisocyanates having 2 to 12 carbon atoms include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 2.2.4-
Trimethylhexamethylene diisocyanate, lysine diisocyanate; C4-C18 alicyclic diisocyanates include 1.4-cyclohexane diisocyanate, 1-isocyanate-3-isocyanate methyl-3.5.5-trimethylcyclohexane (IPDI), 4.4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), methylcyclohexylene diisocyanate (hydrogenated TDI), isopropylidene dicyclohexyl-4,4'-diisocyanate; aromatic aliphatic diisocyanates having 8 to 12 carbon atoms include xylylene diisocyanate; aromatic diisocyanates include diethylbenzene diisocyanate, Diisocyanate (TDI), diphenylmethane diisocyanate (MDI), modified MDI (carbodiimide modification, etc.),
Examples include naphthylene diisocyanate. Among these, preferred are aliphatic diisocyanates and cycloaliphatic diisocyanates,
Particularly preferred are hexamethylene diisocyanate, IPDI and hydrogenated MDI. Methods for producing the urethane resin (a) include a method in which all reaction components are polymerized at once (one shot method) and a method via a prepolymer (prepolymer method), with the prepolymer method being preferred. For example, (1) a method in which a polyisocyanate compound and an active hydrogen-containing compound are reacted to have an excess of NCO to form a prepolymer with less than NCO, and the remaining NCO groups are terminated with a reaction terminator. (2) A polyisocyanate compound and an active hydrogen-containing compound are reacted to create an excess of NCO, and then a low molecular weight glycol or a low molecular diamine is reacted to create an excess of NCO.
The remaining NCO after making the prepolymer less than
An example is a method of terminating the group with a reaction terminator. Examples of the reaction terminator include monoamines (dialkylamines such as di-n-butylamine) and monoalcohols (ethyl alcohol, t-butyl alcohol, etc.). Monoamines are preferred when aliphatic or cycloaliphatic diisocyanates are used as the polyisocyanate component, and monoalcohols are preferred when aromatic diisocyanates are used. During the reaction, NCO/active hydrogen-containing groups (OH,
The _NH2 , NH) ratio is usually between 0.9 and 1.1, preferably substantially 1. The reaction temperature is usually 20-150°C. The reaction is carried out under normal pressure or elevated pressure. A solvent may be used for the purpose of adjusting the viscosity of the reaction system during the reaction. This solvent is an aromatic hydrocarbon solvent (toluene,
xylene, etc.), ketone solvents (methyl ethyl ketone, methyl isobutyl ketone, etc.), ester solvents (ethyl acetate, n-butyl acetate, octyl acetate, etc.), cyclic ether solvents (1,4-dioxane, tetrahydrofuran, etc.), formamide solvents ( N,N-dimethylformamide, etc.), alcoholic solvents (methyl alcohol, ethyl alcohol, isopropyl alcohol, etc.), polyhydric alcohol derivatives (ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc.), and mixed solvents of two or more of these can be given. A catalyst may be used for the purpose of promoting the reaction. As a catalyst, tertiary amines [triethylamine, ethylmorpholine, tetramethylguanidine, 1-
(2-hydroxypropyl)imidazole, N-
methyl-N′-hydroxyethylpiperazine, etc.], metal salts (octolates or naphthenates of lead, iron, chromium, nickel, zinc, etc.),
Examples include organic tin compounds (dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dioctyltin dilaurate, dibutyltin dimaleate, etc.). The amount of catalyst used is usually 0.0005 to 3%, preferably 0.001 to 1%, based on the total weight of the active hydrogen-containing component and the polyisocyanate component. The resulting urethane resin (a) usually has a molecular weight of
5000-1000000. Viscosity is usually 100~100000cps/20℃ (30% solution)
It is. The content of polybutadiene glycol in the urethane resin is usually 30-85% by weight. The content of urethane bonds in urethane resin is usually 5 to 20% by weight.
It is. The terminal of the urethane resin may be an OH group, may be blocked with a reaction terminator, or may be an NCO group. Examples of the chlorinated hydrocarbon resin (b) in the present invention include chlorinated polyethylene, chlorinated polypropylene, chlorinated rubber, modified products thereof, and mixtures of two or more thereof. Examples of modified substances include polymerizable acrylic compounds (acrylic acid, methacrylic acid, or alkyl esters thereof, etc.) or unsaturated polycarboxylic acids (anhydrides) (maleic acid, maleic anhydride, itacon) to these chlorinated hydrocarbon resins. JP-A No. 57-28123
Those described in the above publication, or those prepared by chlorinating polyolefin obtained by graft polymerization of the above-mentioned unsaturated polycarboxylic acid (anhydride), for example,
Examples include those described in JP-A No. 10916 and JP-A-57-36128. The bound chlorine content of these chlorinated hydrocarbon resins is usually 10 to 70% by weight, preferably 15 to 45% by weight. If the amount of combined chlorine is less than 10% by weight, the coating agent composition of the present invention will have insufficient uniformity, and if it exceeds 70% by weight, the weather resistance of the coating film will decrease. In the coating agent of the present invention, the content of the chlorinated hydrocarbon resin (b) is usually 3 to 70%, preferably 5 to 70%, based on the total weight of (a) and (b).
It is 50%. If the content of (b) is less than 3%, the adhesion to the polyolefin molded product will not be sufficient, and if it exceeds 70%, the weather resistance of the coating will decrease. In the coating agent of the present invention, the above (a)
In addition to the components (b) and (b), an organic solvent may be added if necessary. In addition to the same solvents as those used in the production of urethane resin (a), halogenated hydrocarbon solvents (dichloroethane, perchlorethylene, dichlorobenzene, etc.) and two or more of these organic solvents are used. A mixed solvent of can be used. Among these, aromatic hydrocarbon solvents are preferred. The amount of solid content of the coating agent of the present invention is usually 5 to 5.
The amount amounts to 50% by weight, preferably 10-35% by weight. The coating agent of the present invention has solvent resistance of the coating film,
For the purpose of improving water resistance, heat resistance, smoothness, etc., other urethane resins or resins commonly used as paint vehicles such as acrylic, melamine, and alkyd resins may be appropriately mixed. Examples of these resins include those described in "Synthetic Resin Paints" (Kobunshi Publishing Co., Ltd., published December 10, 1960). When mixed, the total weight of (a) and (b) in the total resin is usually 50% or more,
Preferably, this is done so that the ratio is 65% or more. Further, the coating agent of the present invention may contain conventional paint additives such as pigments, dispersants, and anti-sag agents. The amount thereof is usually 50 parts by weight or less, preferably 30 parts by weight or less, based on 100 parts by weight of the solid content of the coating agent of the present invention. A polyolefin molded product (particularly a propylene polymer molded product) is suitable as the base material to which the coating agent of the present invention is applied. In addition, it can also be used for other plastic molded products, wood, paper, metal, etc. The coating agent of the present invention may be applied to the substrate by any conventional method, such as brushing, spraying, or applying the coating agent of the present invention to the substrate.
It can be applied using a coating method such as dipping. The coating amount is usually 5 to 50 μm in dry film thickness. Usually 5~ after application
After setting at room temperature for 20 minutes, it is further dried at room temperature or heated. Normally 3 when drying at room temperature
time to 5 days, usually at 70 to 130℃ for heat drying.
It takes between 10 and 45 minutes. Applications can be made directly to the substrate (one coat), wet-on-wet, or further applied to the dried coating (two coats).
It can also be done by applying multiple coats or more. A topcoat is usually applied to the coating film coated and dried in this manner. The top coat may be thermoplastic or thermosetting, and includes commonly used paints such as acrylic, alkyd, urethane, epoxy, melamine alkyd, and acrylic urethane paints. .
As these paints, those described in the above-mentioned "synthetic resin paints" can be used. The coating agent of the present invention has the following effects. (1) Excellent adhesion to both the polyolefin base material and top coat. (2) A uniform composition can be obtained. (3) Excellent stability of solution viscosity over time. (4) A coating film with good water resistance, solvent resistance, and chemical resistance can be obtained. In addition, the coating agent of the present invention has good pigment dispersibility and provides a coating film with good smoothness. The coating agent of the present invention is preferably used as a coating agent for polyolefin molded articles, particularly propylene polymer molded articles, and is also suitably used as an adhesive for these molded articles and a vehicle for printing ink. It can also be used as a coating for other plastics, wood, paper, metal, etc., as an adhesive, and as a vehicle for printing inks. EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples and Test Examples, but the present invention is not limited thereto. Note that "Example, Comparative Example, and Test Example Middle" indicate parts by weight unless otherwise specified. Each test method and measurement method in the test example is as follows. (1) Gloss The specular reflectance at 60°C was measured for the coated surface of each coated board. (2) Initial adhesion JISK5400 cellophane tape test was conducted on the coated surface of each coated board. (3) Water resistance Each coated board was immersed in warm water at 40°C for 240 hours, then left at room temperature for 1 hour to measure gloss and perform a cellophane tape test. (4) Solvent resistance Each coated plate is coated with n-hexane/n-heptane = 1/
After being immersed in 1 mixed solvent at 20°C for 24 hours, the samples were left at room temperature for 1 hour, and gloss measurements and cellophane tape tests were performed. (5) Weather resistance Each coated board was placed in a sunshine weather meter for 1000 hours in accordance with JISK5400, then left at room temperature for 1 hour, and subjected to gloss measurement and cellophane tape test. Example 1 Polybutadiene glycol (NISSOPBG-1000, hydroxyl value
72.4) 150 parts, trimethylolpropane 0.75 parts,
9.2 parts of ethylene glycol, 158.6 parts of IPD, 0.007 parts of dioctyltin dilaurate, 270 parts of toluene, and 135 parts of 1,4-dioxane were charged into a 1-4-necked colben, and the system was sealed and then heated to 90-95°C. The reaction was continued for 8 hours, cooled to below 50°C, and 80 parts of isopropyl alcohol, 4.4'-
A mixture of 1.0 part of diaminobis(cyclohexyl)methane and 1.2 parts of di-n-butylamine was added to obtain a urethane resin solution. A coating agent of the present invention was obtained by mixing 17.5 parts of a 60% chlorinated polypropylene toluene solution (Super Chron 814H, manufactured by Sanyo Kokusaku Pulp) with 100 parts of this resin solution. Table 1 shows the appearance of this solution. Example 2 150 parts of the same polybutadiene glycol used in Example 1, 1.5 parts of trimethylolpropane,
1.4-bis(2-hydroxyethoxy)benzene
22.6 parts of IPDI, 51.9 parts of IPDI, 0.007 parts of dioctyltin dilaurate, 280 parts of toluene and 140 parts of 1,4-dioxane were charged into a four-necked colben, and after the system was sealed, the temperature was raised to 90 to 95°C. After continuing the reaction at this temperature for 10 hours, it was cooled to below 50°C and
1.1 parts of butylamine was added to obtain a urethane resin solution. 29.2 parts of a 60% chlorinated polypropylene toluene solution (Super Chron 814H, manufactured by Sanyo Kokusaku Pulp) was mixed with 100 parts of this solution to obtain a coating agent of the present invention. Table 1 shows the appearance of this solution. Example 3 A urethane resin solution was obtained by carrying out the same operation as in Example 1 using hydrogenated polybutadiene glycol obtained by hydrogenating 99.2% of the polybutadiene glycol used in Example 1. Add 100 parts of this solution to chlorinated polypropylene (Hardren 13-LP, manufactured by Toyo Kasei).
A coating agent of the present invention was obtained by mixing 52.5 parts of a 20% toluene solution. Table 1 shows the appearance of this solution. Example 4 To 100 parts of the urethane resin solution obtained in Example 1, 4
20% by weight of polypropylene chloride (combined chlorine content 20% by weight) with addition of maleic anhydride
A coating agent of the present invention was obtained by mixing 70 parts of a toluene solution. Table 1 shows the appearance of this solution. Comparative Example 1 Polybutadiene glycol used in Example 1
24 parts, trilimethylolpropane 0.24 parts, ethylene glycol 80 parts, IPDI 168 parts, dioctyltin dilaurate 0.007 parts, toluene 216 parts and 1.4 parts.
- 216 parts of dioxane was charged into a four-necked kolben, the system was sealed, and the temperature was raised to 80-85°C. After continuing the reaction at this temperature for 6 hours, it was cooled to below 50°C, and 17.7 parts of di-n-butylamine was added to obtain a urethane resin solution. Add 100 parts of this solution to a 60% solution of chlorinated polypropylene toluene (Super Chron)
814H) were mixed. Table 1 shows the appearance of this solution. Comparative Example 2 To 100 parts of the urethane resin solution obtained in Example 1, 50 parts of a 60% solution of chlorinated polypropylene toluene (Superchron 814H) was mixed. Table 1 shows the appearance of this solution. Comparative Example 3 50 parts of toluene was mixed with 100 parts of chlorinated polypropylene toluene 60% solution (Super Chron 814H). Table 1 shows the appearance of this solution.

[Table] Test Example 1 The compositions of Examples 1 to 4 and Comparative Examples 1 to 3 were diluted with toluene so that the solid content was 20% by weight, and 10 parts of titanium oxide and carbon were added to 100 parts of these solutions. 0.1 part of black was mixed and kneaded in a ball mill overnight to obtain a test coating solution. Injection-molded plates (thickness: 2 mm) of propylene-ethylene block copolymer with an ethylene content of 6 mol% were prepared, and the surfaces thereof were degreased with trichloroethane, and then prepared in Examples 1 to 4 and Comparative Examples 1 to 3. The test paint solution was applied to an injection molded plate by spraying. After setting at room temperature for 5 minutes, it was dried in a circulating air dryer at 80°C for 30 minutes (dry film thickness approximately 20μ). A commercially available melamine alkyd topcoat (Flexen #101, manufactured by Nippon Bee Chemical) was applied with thinner (#101) onto each coating film thus obtained.
-10) diluted to 2:1 (weight ratio), applied by spray, set at room temperature for 15 minutes, and baked in a circulating dryer at 120℃ for 30 minutes (dry film thickness approximately 40μ). . Each test was conducted on each coating thus obtained. The test results are shown in Table 2.

【table】

Claims (1)

[Scope of Claims] 1. A coating agent suitable for coating polyolefin molded articles made of a polybutadiene glycol urethane resin (a) and a chlorinated hydrocarbon resin (b). 2. Claim 1, wherein (a) is a resin comprising an active hydrogen-containing compound component consisting of a polyol containing 50% by weight or more of polybutadiene glycol and, if necessary, another active hydrogen-containing compound, and a polyisocyanate component. coating agent. 3. Claim 1 in which the content of (b) is 3 to 70% based on the total weight of (a) and (b)
The coating agent according to item 1 or 2.