United States Patent (19) 11 Patent Number: 4,981,889 Baba et al. 45 Date of Patent: Jan. 1, 1991

54 PLASTISOL COMPOSITION (56) References Cited U.S. PATENT DOCUMENTS 75 Inventors: Akira Baba, Ibaraki; Takashi Maebashi; Takashi Nakayama, both 3,423,354 1/1969 Jones ...... 524/145 3,644,229 2/1972. Butler et al. ... 525/29 of Takatsuki, all of Japan 3,917,550 1 1/1975 Clas et al...... 524/297 73 Assignee: Sunstar Gilken Kabushiki Kaisha, 4,623,686 11/1986 Hurnik et al...... 524/659 Osaka, Japan Primary Examiner-Veronica P. Hoke Attorney, Agent, or Firm-Wegner, Cantor, Mueller & 21 Appl. No.: 341,704 Player 22 Filed: Apr. 21, 1989 57 ABSTRACT A plastisol composition which comprises a polyvinyl 30 Foreign Application Priority Data chloride, a plasticizer and a blocked isocyanate com pound as an adhesion-modifier, supplemented with a Apr. 26, 1988 JP Japan ...... 63-107099 powdery curing agent for an epoxy resin having a melt 51) Int. Cl...... C08K 5/12; C08K 5/521 ing point of 50 to 150 C. which is surface-treated. The 52 U.S. C...... 524/109; 524/143; plastisol composition of the present invention has an 524/145; 524/297; 524/314; 525/111; 525/121 improved adhesion property at a lower temperature and 58 Field of Search ...... 525/124, 127, 129, 111, is useful as an adhesive, sealing agent and coating agent, 525/121; 524/569, 109, 112, 114, 206, 257, 296, 297,143, 145, 314, 196 8 Claims, No Drawings 4,981,889 1. 2 chloride (e.g. vinylidene chloride, vinyl bromide, etc.), PLASTSOL COMPOSTION and the like. The plasticizer used in the present invention may be The present invention relates to a plastisol composi those commonly used for polyvinyl chloride and in tion, more particularly, a plastisol composition compris cludes, but not limited to, phthalic acid di(C4-C10)alkyl ing polyvinyl chloride as a main component, a plasti or (CA-C10)alkyl-(C6-C8)aryl esters such as di(n-butyl) cizer, a blocked isocyanate compound as an adhesion phthalate, octyldecyl phthalate, diisodecyl phthalate, modifier and a powdery curing agent having a melting di(2-ethylhexyl) isophthalate, di(2-ethylhexyl) phthal point of 50' to 150' C. which is surface-treated, said ate, butylbenzyl phthalate, dioctyl phthalate (DOP), composition having an improved adhesion properties 10 dinonyl phthalate, diisononyl phthalate (DINP), dihep when gelated under low temperature conditions such as tyl phthalate and butyl phthalyl butyl glycolate; ali at 110' to 130' C. for 15 to 30 minutes. phatic dibasic acid esters such as dioctyl adipate, dide cyl adipate, dioctyl sebacate, di(2-ethylhexyl) adipate, TECHNICAL BACKGROUND AND PRIOR ART diisodecyl adipate, di(2-ethylhexyl) azelate, dibutyl seb A plastisol composition comprising polyvinyl chlo 15 acate and di(2-ethylhexyl) sebacate; phosphoric acid ride as a main component has been employed as adhe esters such as tricresyl phosphate, trioctyl phosphate, sives, sealant or coating material in various fields. As tributyl phosphate, tri-2-ethylhexyl phosphate and 2 such a type of plastisol composition, for example, there ethylhexyldiphenyl phosphate; epoxy type plasticizers is known a composition which comprises a polyvinyl such as epoxydized soybean oil and 2-ethylhexyl epoxy chloride, a plasticizer and a blocked compound of diiso 20 dized tall oil fatty acid ester, and other polyester type cyanate polymer with a long-chain alkylated phenol as plasticizers, which are used alone or in combination of an adhesion-modifier (cf. Japanese Patent First Publica at least two thereof. Such plasticizer has an influence on tion No. 41278/1987). This plastisol composition, how viscosity of the plastisol and properties of the gellated ever, has been found to have less adhesion properties product, and may usually be used in an amount of under low temperature conditions such as 110 to 130 25 65-130 parts (parts by weight, hereinafter the same) per C., though it has an excellent storage stability under 100 parts of polyvinyl chloride. conditions of high temperature and high humidity with The blocked isocyanate compound used in the pres out foaming and discoloration and is capable of forming ent invention as an adhesion-modifier is prepared by a gelated compound with an excellent adhesion strength blocking a diisocyanate polymer with a conventional under high temperature conditions. 30 procedure. SUMMARY OF THE INVENTION The above diisocyanate polymer can be prepared by a conventional method, that is, by polymerizing a diiso The present inventors have intensively studied to cyanate monomer such as an aliphatic diisocyante (e.g. improve adhesion properties of the plastisol composi hexamethylene diisocyanate, lysine diisocyanate), an tion under low temperature conditions, and as a result, 35 alicyclic diisocyanate (e.g. hydrogenated diphenyl it was found that the adhesion properties under low methane diisocyanate, isophorone diisocyanate, hydro temperature conditions can remarkably be improved by genated tolylene diisocyanate) and an aromatic diisocy adding a specific curing agent for an epoxy resin to the anate (e.g. tolylene diisocyanate, diphenylmethane di above plastisol composition. isocyanate, naphthylene diisocyanate, xylene diisocya That is, the present invention provides a plastisol nate) in an inert solvent (e.g. ethyl acetate, methyl ace composition which comprises a polyvinyl chloride, a tate, butyl acetate, chlorobenzene) or in a plasticizer plasticizer and a blocked isocyanate compound as an (phthalic acid esters, phosphoric acid esters, adipic acid adhesion-modifier, supplemented with a powder curing esters, trimelitic acid esters). The diisocyanate polymer agent for an epoxy resin having a melting point of 50' to may also be an isocyanate-terminated urethane prepoly 150' C. which is surface-treated. 45 mer which is prepared by reacting a polyalkylene ether DETAILED DESCRIPTION OF THE polyol with an excess amount of the above diisocyanate INVENTION OOer. The polyvinyl chloride used in the present invention A blocking agent used for blocking the above diiso may be those commonly used for plastisol, including 50 cyanate polymer includes (C2-C4) alcohols such as those prepared by polymerizing vinyl chloride alone or ethanol, propanol, butanol and isobutanol; phenols such together with other copolymerizable monomer by as phenol, cresol, xylenol and p-nitrophenol; long emulsion polymerization, suspension polymerization, chained (C4-C10)-alkylphenols such as butylphenol, bulk polymerization, solution polymerization and the hexylphenol, octylphenol and nonylphenol; activated like. Such copolymerizable monomer includes, for ex 55 methylene compounds such as ethyl malonate, ethyl ample, vinyl esters of (C2-C10)alkanoic acids (e.g. vinyl acetoacetate and acetylacetone; (C2-C4)-alkanoic or acetate, vinyl propionate, vinyl laurate, etc.), acrylic alkenoic acid amides such as acetamide, acrylamide and acid (C1-C4)alkyl esters (e.g. methyl acrylate, ethyl acetanilide; (C2-C6)dibasic alkanoic acid imides such as acrylate, butyl acrylate, etc.), methacrylic acid (C1-C- succinimide and maleinimide; mono- or di-(C1-C4)- 4)alkyl esters (e.g. methyl methacrylate, ethyl methac alkyl-substituted imidazoles such as 2-ethylimidazole rylate, etc.), maleic acid di(C1-C4)alkyl esters (e.g. di and 2-ethyl-4-methylimidazole; lactams such as 2-pyr butyl maleate, diethyl maleate, etc.), fumaric acid di(C- rolidone and e-caprolactam; oximes of ketone or alde 1-C4)alkyl esters (e.g. dibutyl fumarate, diethyl fumar hyde such as acetoxime, methyl ethyl ketoxime, cyclo ate, etc.), vinyl (C1-C10)-alkyl ethers (e.g. vinyl methyl hexanone oxime and acetaldoxime; ethyleneimine, bisul ether, vinyl butyl ether, vinyl octyl ether, etc.), vinyl 65 fates and the like, preferably long-chained (CA-C10)al cyanates (e.g. acrylonitrile, methacrylonitrile, etc.), kylphenols, lactams and oximes, in view point of stor a-olefins (e.g. ethylene, propylene, styrene, etc.), vinyl age stability and curing characteristics, and most prefer halogenides or vinylidene halogenides other than vinyl ably butylphenol, hexylphenol, octylphenol, nonylphe 4,981889 3 4. nol, e-caprolactam, methyl ethyl ketoxime and cyclo Group B compounds): dibasic (C2-C10) carboxylic hexanone oxime. acids such as succinic acid, adipic acid, sebacic acid, These blocking agents are reacted with the diisocya phthalic acid, terephthalic acid and dimer acid; nate polymer to prepare a blocked isocyanate com (C1-C4)-alkane- or (C6-C8)aryl-sulfonic acids such as pound. In this reaction, about 0.90-1.5 equivalents, pref ethanesulfonic acid and p-toluenesulfonic acid; isocya erably about 1.0-1.3 equivalents of the blocking agent is nates such as tolylene diisocyanate, 4,4'-diphenyl diiso employed per 1 mol of the isocyanate group. When the cyanate and hexamethylene diisocyanate; p-hydroxys blocking agent is used in an amount less than 0.9 tyrene resin; phenol resin; epoxy resin; and the like. equivalents, resulting blocked isocyanate compound Amoung the above powdery curing agents having a may contain free isocyante groups to have a bad 10 melting point of 50 to 150' C., preferable are those influence on the storage stability, and on the other containing at least two active hydrogens of amino hand, when the amount of the blocking agent exceeds group in a molecule for example, the above aromatic 1.5 equivalents, the unreacted blocking agent may amines; addition product of aliphatic polyamines (e.g. migrate or volatilize to cause some problems or it is not ethylenediamine, diethylenetriamine, triethylenetetra preferable from economical standpoint. 15 mine, tetraethylenepentamine, hexamethylenediamine) The thus prepared blocked isocyanate compound, as with an epoxy resin; condensation products of an ali a 20% solution in di(2-ethylhexyl) phthalate, may be phatic polyamine and an aliphatic or aromatic dicarbox used in an amount ranging from 35 to 70 parts (7 to 14 ylic acid; polyureas such as a tolylenediisocyanate ad parts as an effective component) per 100 parts of polyvi duct of and hexamethylenediisocyanate adduct of an nyl chloride. 20 aliphatic amine; modified compounds such as succinic The powdery curing agent for an epoxy resin which acid hydrazide, adipic acid hydrazide and dicyandia is surface-treated (hereinafter referred to as "surface mide or those containing at least one tertiary amino treated curing agent') of the present invention is pre group in a molecule for example, the above imidazoles; pared by dispersing a powdery curing agent for an adducts of a secondary amino group-containing com epoxy resin in a suitable insoluble medium and then 25 pound (e.g. imidazoles, carboxylic acid salts of imidaz adding a surface-treating agent thereto, or alternatively, oles, dimethylamine, diethylamine, dipropylamine, di(- by spraying a surface-treating agent to a powdery cur hydroxymethyl)amine, di(hydroxyethyl)amine) with an ing agent which is in a fluidized form in a gas stream. epoxy resin. Preferable powdery curing agents in view The above powdery curing agent may be formed to of easiness of gelation and storage stability are imidaz have a suitable form with conventional powdering pro 30 ole derivatives containing at least one hydroxy group in cedures (using, for example, hammer mill grinder, jet a molecule e.g. imidazoles having optionally mono- or grinder, ball mill grinder) and is required to have a di-(C1-C12)alkyl or phenyl substituent such as imidaz melting point of from 50 to 150° C., preferably from ole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4- 60' to 120° C. When the melting point is below 50° C., methylimidazole, 2-isopropylimidazole, 2 the powdery curing agent may coagulate when stored, 35 undecylimidazole and 2-phenylimidazole; adducts of a thereby making difficult for handling, and when the salt of the imidazoles with a carboxylic acid (e.g. acetic melting point exceeds 150 C., adhesion property of the acid, lactic acid, salicylic acid, benzoic acid, adipic acid, obtained plastisol composition when gelated under low phthalic acid, citric acid, tartaric acid, maleic acid, temperature conditions may be deteriorated. trimellitic acid) and an epoxy compound containing at Such powdery curing agent includes aromatic amines least one epoxy group in a molecule (e.g. butyl glycidyl (e.g. metha-phenylenediamine, para-phenylenediamine, ether, hexyl glycidyl ether, phenyl glycidyl ether, p diaminodiphenylmethane); phthalic or succinic acid xylyl glycidyl ether, glycidyl acetate, glycidylbutylate, anhydrides having optionally halogen or (C1-C4)alkyl glycidylhexoate, glycidyl benzoate). substituent (e.g. phthalic anhydride, 3-chlorophthalic The surface-treating agent includes, for example, anhydride, 4-chlorophthalic anhydride, tetrahydroph 45 carboxylic acids such as (C1-C4)alkanoic acids (e.g. thalic anhydride, anhydrous dimethylsuccinate); imid formic acid, acetic acid, propionic acid, butyric acid), azoles having optionally (C1-C12)-alkyl or phenyl sub dibasic (C2-C8)alkanoic acids (e.g. adipic acid, succinic stituent (e.g. inidazole, 2-methylimidazole, 2 acid), phenyl-dicarboxylic acids (e.g. phthalic acid, undecylimidazole, 4-methylimidazole, 2 terephthalic acid); (C1-C4)alkane- or (C5-C8)aryl-sul phenylimidazole) and the like. Further, the powdery 50 fonic acids (e.g. ethanesulfonic acid, p-toluenesulfonic curing agent includes the following group A com acid); isocyanates (e.g. phenyl isocyanate, 4.4- pounds or reaction products of group A compounds diphenylmethane diisocyanate, tolylene diisocyanate, and group B compounds. hexamethylene diisocyanate); (C2-C4)-alkanoic or diba Group A compounds: aliphatic polyamines such as sic (C2-C8)alknoic acid halides (e.g. acetyl chloride, ethylenediamine, diethylenetriamine, triethylenetetra 55 propionic acid chloride, succinic acid chloride, adipic mine, tetraethylenepentamine and diethylamino acid chloride); (C2-C4)alkanoic or phenyl-dicarboxylic propylamine; aromatic polyamines such as diaminodi acid anhydrides (e.g. acetic anhydride, propionic anhy phenylsulfone and bis(aminomethyl)diphenylmethane; dride, phthalic anhydride); epoxy compounds contain dibasic or tribasic carboxylic acid anhydrides such as ing at least one epoxy group; p-hydroxystyrene resins; trimellitic anhydride, pyromellitic anhydride, hexahy phenol resins and the like, preferable one being isocya drophthalic anhydride and succinic anhydride; dibasic nates containing at least one isocyanate group in a mole (C2-C10)carboxylic acid hydrazides such as adipic acid cule, particularly tolylene diisocynate and 4,4'- hydrazide, succinic acid hydrazide, sebacic acid hydra diphenylmethane diisocyanate. zide and terephthalic acid hydrazide; dicyandiamide; The surface-treated curing agent thus prepared from mono- or di-(C1-C12)alkyl-substituted imidazoles such 65 the powdery curing agent and the surface-treating as 2-ethylimidazole, 2-isopropylimidazole, 2 agent may be used in an amount ranging from 0.3 to 5 dodecylimidazole and 2-ethyl-4-methylimidazole; car parts, preferably from 0.6 to 3 parts, per 100 parts of boxylic acid salts of the above imidazoles; and the like. polyvinyl chloride resin. When the used amount of the 4,981,889 5 6 surface-treated curing agent is below 0.3 parts, the de TABLE 1-continued sired effect of improving adhesion properties at a lower - E - - Comp. Ex temperature is not attained, and when the amount is Component 2 2 over 5 parts, the adhesion properties at a lower temper Adhesion properties at a lower temp. (O O) ature is no more improved but it is rather economically (note)'. Kaneka PCH-12Z (manufactured by Kanegahuchi Kagaiku Kogyo Kabu disadvantageous. shiki Kaisha) 'Zeon G-51 (manufactured by Nippon Zeon Co., Ltd., blended type) In place of a part of the surface-treated curing agent, *S-202 (blocked aromatic diisocyanate polymer with nonylphenol, manufactured the plastisol composition of the present invention may by Kyoeisha Fats and Oils Co., Ltd., used as a 20% solution in DOP) *"Nobacure-3721 (manufactured by Asahi Chemical Industries, Co., Ltd.) further contain a conventional latent curing agent for an 10 ADH (adipic acid dihydrazide) (manufactured by Nippon Hydrazine Industries epoxy resin (e.g. dicyandiamide, phthalic anhydride, Co., Ltd., used as a 50% solution in DINP) *SP (manufactured by Takehara Kagaku Co., Ltd.) trimellitic anhydride, tetrahydrophthalic anhydride, *Glassballoon Z-37 (manufactured by Asahi Glass Co., Ltd., specific gravity: 0.36) hexahydrophthalic anhydride, adipic acid dihydrazide, "Whiton B (manufactured by Shiraishi Calucium Co., Ltd.) sebacic acid dihydrazide, isophthalic acid dihydrazide, 'QCX (manufactured by Inoue Sekkai Co., Ltd.) terephthalic acid dihydrazide, diaminodiphenylsulfone, 15 a phenol resin, a melamine resin, a urea resin) to reduce We claim: the cost. 1. In a plastisol composition comprising a polyvinyl The plastisol composition of the present invention chloride, a plasticizer and a blocked isocyanate com comprises the polyvinyl chloride, the plasticizer, the pound, the improvement which comprises further a 20 powder curing agent for an epoxy resin having a melt blocked isocyanate compound and the surface-treated ing point of 50 to 150 C., said powder curing agent curing agent (and optionally latent curing agent) in the being treated with a surface-treating agent selected above fixed ratio. The plastisol composition of the pres from the group consisting of (C1-C4)alkanoic acids, ent invention may further contain conventional addi dibasic (C2-C8)alkanoic acids, phenyl-dicarboxylic tives such as fillers (precipitated potassium carbonate 25 acids, (C1-C4)alkane- or (C5-C8)aryl-sulfonic acids, which may be surface-treated with fatty acid or resin isocyanates, (C2-C4)alkanoic or dibasic (C2-C8)al acid, heavy calcium carbonate, calcium oxide, clay, kanoic acid halides, (C2-C4)alkanoic or phenyl-dicar talc, silica, hollow glass powder), dehydrochlorination boxylic acid anhydrides, epoxy compounds containing inhibiting agents (e.g. metallic soap, an organic tin com at least one epoxy group, p-hydroxystyrene resins and pound), heat stabilizers, pigments (e.g. titanium white), 30 phenol resins. and the like. 2. The composition according to claim 1, wherein the The present invention is more specifically illustrated powdery curing agent is a member selected from the by the following Examples and Comparative Examples group consisting of aromatic amines, addition products but should not be construed to be limited thereto. of an aliphatic polyamine with an epoxy resin, conden 35 sation products of an aliphatic polyamine and an ali EXAMPLES 1 TO 2 AND COMPARATIVE phatic or aromatic discarboxyilic acid, polyureas, suc EXAMPLES 1 to 2 cinic acid hydrazide, adipic acid hydrazide, dicyandia (1) Preparation of plastisol compositions mide, imidazoles, and adducts of a secondary amino group-containing compound with an epoxy resin. The components listed in the following Table 1 were 3. The composition according to claim 1, wherein the mixed and dispersed and degassed under vacuum to powdery curing agent is a member selected from the prepare plastisol compositions. group consisting of imidazole compounds containing at (2) Test for adhesion properties at a lower temperature least one hydroxy group in a molecule, adducts of a salt of the imidazoles with a carboxylic acid, and an epoxy Each composition prepared above was applied onto a 45 compound containing at least one epoxy group in a cationic electro-deposition steel plate and the plate was molecule. heated at 120' C. for 20 minutes, followed by peel test 4. The plastisol composition of claim 1 which addi with nail to evaluate adhesion properties of each com tionally comprises a latent curing agent for an epoxy position. reS1 The evaluation was made in two-rank i.e. 50 5. The plastisol composition of claim 1 which com O): excellent prises 100 parts by weight of the polyvinyl chloride, 65 X: wrong to 130 parts by weight of the plasticizer, 35 to 70 parts The results are shown in Table 1. by weight of the blocked isocyanate compound, and 0.3 to 5 parts by weight of the powdery curing agent. TABLE 1. 55 6. The plastisol composition of claim 1 wherein said blocked isocyanate compound is prepared by blocking a Component 1 2 2 diisocyanate polymer with a blocking agent selected Polyvinyl chloride" 60 60 60 60 from (C2-C4)alcohold, phenols, (C4-C10)alkylphenols, Polyvinyl chloride? 40 40 40 40 DOP 30 30 30 30 60 activated methylene compounds, (C2-C4)alkanoic or Blocked isocyanate compound 50 SO 50 50 alkenoic acid amides, (C2-C6)dibasic alkanoic acid im Surface-treated curing agent' 2.4 0.6 - - ides, mono- or di(C1-C4)alkyl-substituted imidazoles, Latent curing agent' - 2 - - lactams, oximes of ketone or aldehyde, ethyleneimine, Surface-treated calcium carbonate" 25 25 25 35 and bisulfate. Hollow glass powder'7 6 6 6 65 7. The plastisol composition of claim 1 wherein said Heavy calcium carbonate' - m 35 Kerosine 15 15 15 15 powdery curing agent is a member selected from the Calcium oxide' 10 10 10 10 group consisting of aromatic amines, phthalic or suc Specific gravity 1.19 1.19 1.19 1.37 cinic acid anhydrides having optionally halogen or 4,981,889 7 S (C1-C4)alkyl substituent and imidazoles having option hydrazides, dicyandiamide, mono- or di-(C1-C1 ally (C1-C12)alkyl or phenyl substituent. 2)alkyl-substituted imidazoles, carboxylic acid salts 8. The plastisol composition of claim 1 wherein said powdery curing agent is a member selected the group A of the imidazoles; compounds or reaction products of group A com Group B compounds): dibasic (C2-C10) carboxylic pounds and group B compounds: acids, (C1-C4)alkane- or (C6-C8)aryl-sulfonic Group A compounds: aliphatic polyamines, aro acids, isocyanates, p-hydroxystyrene resin, phenol matic polyamines, dibasic or tribasic carboxylic resin and epoxy resin. acid anhydrides, dibasic (C2-C10)carboxylic acid E. g. : : : 10

15

20

25

30

35

40

SO

55

60

65