JP2005314441A - Adhesion-imparting agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an adhesion-imparting agent for an acrylic plastisol, which has excellent low-temperature curability, storage stability, adhesiveness to a coated metal surface and chipping resistance since a conventional acrylic plastisol has excellent low-temperature curability and storage stability, however, not sufficient adhesiveness to a coated metal surface and chipping resistance. <P>SOLUTION: The adhesion-imparting agent for an acrylic plastisol comprises a blocked polyurethane compound and a heterocyclic polyamine. The acrylic plastisol comprises the adhesion-imparting agent, an acrylic polymer and a plasticizer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an adhesiveness imparting agent. More specifically, the present invention relates to an adhesion imparting agent for acrylic plastisol, which is coated on an outer plate of an automobile and prevents corrosion of a car body steel plate, and a plastisol using the same.

  Conventionally, plastisol having adhesion to a metal coating surface by cationic electrodeposition or the like has been vinyl chloride plastisol. However, in recent years, replacement from vinyl chloride plastisol to acrylic plastisol has been promoted in consideration of the environment. As adhesive imparting agents for acrylic plastisols, those composed of a blocked polyurethane compound and a solid hydrazine-based curing agent (for example, see Patent Documents 1 and 2) are known.

JP 2001-329135 A JP 2001-329208 A

However, although the acrylic plastisols of Patent Documents 1 and 2 are excellent in low-temperature curability and storage stability, adhesion to metal coated surfaces and chipping resistance are not sufficient.
An object of the present invention is to provide an adhesiveness-imparting agent for acrylic plastisol that has excellent low-temperature adhesion and chipping resistance to a metal-coated surface.

The inventors of the present invention have arrived at the present invention as a result of intensive studies to solve the above problems.
That is, the present invention relates to an adhesiveness-imparting agent for acrylic plastisol comprising the blocked polyurethane compound (A) and the heterocyclic polyamine (B); an acrylic material comprising the adhesion-imparting agent, an acrylic polymer, and a plasticizer. Plastisol.

The acrylic plastisol containing the adhesiveness imparting agent of the present invention has the following effects. (1) Excellent storage stability.
(2) Sufficient curability by heat treatment at a low temperature for a short time.
(3) It has strong adhesion to the metal coating surface at a relatively low temperature.
(4) The acrylic plastisol coating on the metal painted surface has excellent chipping resistance.

The adhesion-imparting agent (C) of the present invention comprises a blocked polyurethane compound (A) and a heterocyclic polyamine (B).
(B) includes the following poly (divalent or higher) amines containing two or more active hydrogens.
(B1) Secondary amine group-containing polyamine Carbon number (hereinafter abbreviated as C) 3-20, such as piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, 1-methyl-3-ethylpiperazine, 1,3- Di (4-piperidyl) propane, pyrazine, 2-hydroxypyrazine, pyrazolidine, 2-methylpyrazolidine and 4-ethylpyrazolidine.
(B2) Primary and secondary amino group-containing polyamines C2-12, such as aminoalkyl-substituted piperazines (such as aminoethylpiperazine) and 3-amino-1,2,4-triazoles.
(B3) Primary amino group-containing polyamine C6-10, such as bis (N-aminoethyl) piperazine and bis (N-aminopropyl) piperazine.

  Of these, (B3) is preferable from the viewpoint of reactivity with (A) described later, adhesion of acrylic plastisol and storage stability, and (B1) and (B2) are more preferable, and particularly preferable. One or more heterocyclic polyamines selected from the group consisting of piperazine and aminoalkyl-substituted piperazine.

  In (A), the terminal isocyanate group of the urethane prepolymer obtained by the reaction of organic poly (divalent to tetravalent or higher) isocyanate (a1) and polyol (a2) is blocked with a blocking agent (a3). Compounds are included.

Examples of the organic polyisocyanate (a1) include the following, and a mixture of two or more thereof.
(1) C (excluding C in the NCO group, the same shall apply hereinafter) 6 to 20 aromatic polyisocyanate diisocyanate (hereinafter abbreviated as DI), such as 1,3- and / or 1,4-phenylene DI, 2 , 4- and / or 2,6-tolylene DI (TDI), 4,4′- and / or 2,4′-diphenylmethane DI (MDI), m- and p-isocyanatophenylsulfonyl isocyanate, 4,4 ′ -Diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatodiphenylmethane, 1,5-naphthylene DI, and m -And p-isocyanatophenylsulfonyl isocyanate; and trifunctional or higher functional PI (such as triisocyanate), such as crude TDI, crude MDI (poly Chi Ren polyphenylene polyisocyanate) and 4,4 ', 4 "- triphenylmethane triisocyanate

(2) C2-18 aliphatic polyisocyanates DI, such as ethylene DI, tetramethylene DI, hexamethylene DI (HDI), heptamethylene DI, octamethylene DI, decamethylene DI, dodecamethylene DI, 2,2,4- and /, 2,4,4-trimethylhexamethylene DI, lysine DI, 2,6-diisocyanatomethylcaproate, 2,6-diisocyanatoethylcaproate, bis (2-isocyanatoethyl) fumarate, bis ( 2-isocyanatoethyl) carbonate and trimethylhexamethylene diisocyanate (TMDI); and tri- or higher functional polyisocyanates (such as triisocyanates), such as 1,6,11 1-undecane triisocyanate, 1,8-diisocyanate-4-isocyanate Mechi Octane, 1,3,6-hexamethylene triisocyanate and lysine ester triisocyanate (phosgenates of the reaction product of lysine and alkanolamine, such as 2-isocyanatoethyl-2,6-diisocyanatohexanoate, 2 -And / or 3-isocyanatopropyl-2,6-diisocyanatohexanoate, etc.)

(3) C4-45 cycloaliphatic polyisocyanates DI, such as isophorone DI (IPDI), 2,4- and / or 2,6-methylcyclohexane DI (hydrogenated TDI), dicyclohexylmethane-4,4′-DI (Hydrogenated MDI), cyclohexylene DI, methylcyclohexylene DI, bis (2-isocyanatoethyl) -4-cyclohexylene-1,2-dicarboxylate and 2,5- and / or 2,6-norbornane DI , Dimer acid DI (DDI); and trifunctional or higher functional PI (such as triisocyanate), for example, bicycloheptane triisocyanate (4) C8-15 aromatic aliphatic polyisocyanate m- and / or p-xylylene DI (XDI), Diethylbenzene DI and α, α, α ′, α′-tetramethylxylylene DI TMXDI)

  Of these, aromatic polyisocyanates are preferable from the viewpoint of adhesiveness of acrylic plastisol, and TDI and MDI are more preferable.

The polyol (a2) has a hydroxyl group equivalent [number average molecular weight per hydroxyl group [number average molecular weight is hereinafter abbreviated as Mn, measured by gel permeation chromatography (GPC)]] of 31 to 3,000. Divalent to hexavalent or higher polyols, for example, low molecular polyols having a hydroxyl equivalent of 31 to less than 250, high molecular polyols having a hydroxyl equivalent of 250 to 3,000 (polyether polyols, polyester polyols, polymer polyols, polycarbonate polyols, etc.) and A mixture of two or more of these may be mentioned.
Among these, from the viewpoint of the viscosity of acrylic plastisol and physical properties of the coating film, a polymer polyol is preferable, a polyester polyol is more preferable, and a polyether polyol is particularly preferable.

Low molecular polyols include polyhydric alcohols and low molecular OH-terminated polymers (polyether polyols and polyester polyols). The polyhydric alcohol includes the following.
Dihydric alcohols (C2-20 or higher), for example C2-12 aliphatic dihydric alcohols [(di) alkylene glycols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,2-, 2,3 -, 1,3- and 1,4-butanediol, 1,6-hexanediol, neopentyl glycol and 3-methylpentanediol (hereinafter abbreviated as EG, DEG, PG, DPG, BD, HD, NPG and MPD, respectively) ), Dodecanediol, etc.]; C6-10 alicyclic dihydric alcohol [1,4-cyclohexanediol, cyclohexanedimethanol, etc.]; C8-20 araliphatic dihydric alcohol [xylylene glycol, bis (hydroxyethyl) ) Benzene etc.];

  Trihydric to octahydric or higher polyhydric alcohols such as (cyclo) alkane polyols and their intramolecular or intermolecular dehydrates [glycerin, trimethylolpropane, pentaerythritol, sorbitol and dipentaerythritol (hereinafter referred to as GR, TMP respectively) , PE, SO and DPE), 1,2,6-hexanetriol, erythritol, cyclohexanetriol, mannitol, xylitol, sorbitan, diglycerin and other polyglycerins, etc.], sugars and their derivatives [eg sucrose, glucose, Fructose, mannose, lactose, and glucoside (such as methyl glucoside)];

  Nitrogen-containing polyols (tertiary amino group-containing polyols and quaternary ammonium group-containing polyols): nitrogen-containing diols such as C1-12 aliphatic, alicyclic and aromatic primary monoamines [methylamine, ethylamine, 1- and 2 -Propylamine, (iso) amylamine, hexylamine, 1,3-dimethylbutylamine, 3,3-dimethylbutylamine, 1-, 2- and 3-aminoheptane, nonylamine, decylamine, undecylamine, dodecylamine, cyclopropyl Amine, cyclopentylamine, cyclohexylamine, aniline, benzylamine, etc.] bishydroxyalkyl (C2-4) compounds [bis (2-hydroxyethyl) products, bis (hydroxypropyl) products, such as US Pat. No. 4,271, Recorded in 217 specification And a quaternized product thereof [a quaternized product of a quaternizing agent or a dialkyl carbonate described in the above US Patent Specification], for example, a quaternary nitrogen atom described in the above US Patent Specification Containing polyols; and trivalent to octavalent or higher nitrogenous polyols such as trialkanol (C2-4) amines (such as triethanolamine) and C2-12 aliphatic, alicyclic, aromatic and heterocyclic polyamines [For example, ethylenediamine, tolylenediamine, aminoethylpiperazine] polyhydroxyalkyl (C2-4) compound [poly (2-hydroxyethyl) compound, bis (hydroxypropyl) compound, etc .: for example, tetrakis (2-hydroxypropyl) ethylenediamine and Pentakis (2-hydroxypropyl) diethyleneto Amines, and similar quaternary compound with these above;

  Sulfo group-containing polyols: those obtained by introducing sulfo groups into the above divalent and trivalent to octavalent or higher polyhydric alcohols, such as sulfoglycerin, sulfoerythritol, sulfodi (hydroxymethyl) benzene, sulfodi (hydroxyethyl) Benzene, sulfodi (hydroxypropyl) benzene, sulfohydroxymethylhydroxyethylbenzene, and salts thereof [metal salts [alkali metal (lithium, sodium, potassium, etc.) salts, alkaline earth metals (calcium, magnesium, etc.) salts, IIB metals] (Such as zinc) salt, ammonium salt, amine (C1-20) salt and quaternary ammonium salt].

  Low molecular OH-terminated polymers include polyether polyols, polyester polyols and polyurethane polyols having an OH equivalent weight of less than 250, as described below. For example, a low-polymerization alkylene oxide (hereinafter abbreviated as AO) ring-opening polymer and a low-mol AO adduct of an active hydrogen atom-containing polyfunctional compound [for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bis (hydroxyethoxy) EO 2-4 mol adduct of benzene and bisphenol A], low-condensation condensation polyester polyol and low-mol lactone adduct of polyol [condensation product of polycarboxylic acid and excess (1 mol per carboxyl group) polyhydric alcohol (Eg, dihydroxyethyl adipate) and 1 mol caprolactone adduct of EG, and low-polymerization polyurethane polyol [excess (1 mol per isocyanate group) polyhydric alcohol reaction product (eg 1 mol TDI and EG2) Anti-Mole Reaction product)].

  Among the polymer polyols, examples of the polyether polyol include AO adducts of low molecular polyols (above and their mixtures), polyoxytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran, and the like. Of these, low molecular polyol AO adducts and polyoxytetramethylene glycol are preferred.

AO added to the low molecular polyol includes C2-12 or more (preferably C2-4) AO, such as ethylene oxide, propylene oxide, 1,2-, 1,3- and 2,3-butylene oxide, tetrahydrofuran. And 3-methyl-tetrahydrofuran (hereinafter abbreviated as EO, PO, BO, THF and MTHF, respectively), 1,3-propylene oxide, isoBO, C5-12 α-olefin oxide, substituted AO such as styrene oxide and epihalohydrin ( Epichlorohydrin and the like), and combinations of two or more of these (random addition and / or block addition).
Of these, preferred are EO, PO, BO, and more preferred are mixtures of two or more thereof.

The polyester polyol includes a condensed polyester polyol, a polylactone polyol, and a castor oil-based polyol.
The condensed polyester polyol includes a polyol (a diol and, if necessary, a trivalent or higher polyol), a polycarboxylic acid (a dicarboxylic acid and, if necessary, a trivalent or higher polycarboxylic acid) or an ester-forming derivative thereof, or a polycarboxylic acid anhydride and It can be produced by reacting with AO.

As the polyol, a low-molecular polyol and / or a polyether polyol can be used. The low-molecular polyol includes those described above, and the polyether polyol includes those having a hydroxyl equivalent of 500 or less.
As the polycarboxylic acid, a dicarboxylic acid, and a dicarboxylic acid and a small proportion (for example, 10 equivalent% or less) of trivalent to tetravalent or higher polycarboxylic acid can be used. Examples thereof include C2-12 aliphatic polycarboxylic acids [dicarboxylic acids (succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, itaconic acid, etc.), tricarboxylic acid (hexane Tricarboxylic acid etc.], C8-15 aromatic polycarboxylic acid [dicarboxylic acid (terephthalic acid, isophthalic acid, phthalic acid etc.), tri- and tetra-carboxylic acid (trimellitic acid, pyromellitic acid etc.)] , And C6-40 alicyclic polycarboxylic acids (eg, dimer acid).
The ester-forming derivatives include acid anhydrides, lower alkyl (C1-4) esters, acid halides (such as acid chlorides), and the like.
Of the polycarboxylic acids, dicarboxylic acids are preferred from the viewpoint of the viscosity of the acrylic plastisol, more preferred are aliphatic dicarboxylic acids, and particularly preferred is adipic acid.

The polylactone polyol can be produced by ring-opening polymerization of a lactone (C4-15, for example, ε-caprolactone, γ-butyrolactone, γ-valerolactone) using a polyol as an initiator.
As the polyol, a low molecular polyol and / or a polyether polyol can be used. Examples thereof include the diol and / or a trihydric or higher polyol, and a polyether polyol having a hydroxyl equivalent weight of 500 or less.
The castor oil-based polyol includes castor oil (ricinoleic acid triglyceride) and transesterification products thereof. The transesterified product is obtained by transesterification of castor oil and a polyol, and examples of the polyol include the low molecular polyol and / or the polyether polyol.

  The polymer polyol is a vinyl monomer [acrylic monomer such as (meth) acrylonitrile, alkyl (C1-20) in a polyol [such as the above-described high molecular polyol (polyether polyol, polyester polyol, etc.) and a mixture of these and the above low molecular polyol]]. ) (Meth) acrylate (such as methyl methacrylate), aromatic hydrocarbon monomer (C8-20, such as styrene), aliphatic hydrocarbon monomer (C2-20, such as α-olefin, butadiene) and the like, and two or more of these Combinations (for example, combined use of acrylonitrile and styrene)] (polymer content, for example, 5 to 70%), for example, those described in JP-A No. 55-118948 can be used.

Polycarbonate polyols can be produced by ring-opening addition / polycondensation of alkylene carbonate using polyol as an initiator, polycondensation (transesterification) of polyol and diphenyl or dialkyl carbonate, or phosgenation of polyol or dihydric phenol (such as bisphenol A). What is obtained is included.
The polyol includes the low-molecular polyol (such as a divalent or trivalent alcohol).
Alkylene carbonates include those having a C2-6 alkylene group, such as ethylene and propylene carbonate. Dialkyl carbonates include those having a C1-4 alkyl group, such as dimethyl, diethyl and di-i-propyl carbonate.

  Among these polyols, from the viewpoint of the viscosity of the acrylic plastisol, preferred are high-molecular polyols, more preferred are low molecular weight polyol AO adducts and polyoxytetramethylene glycol, and particularly preferred is PG PO adduct (hydroxyl equivalent). 250-3,000), TMP PO adducts (hydroxyl equivalents 250-2,500) and / or GR PO adducts (hydroxyl equivalents 250-2,500).

  In the production of the urethane prepolymer having an isocyanate group in the present invention, the equivalent ratio (NCO / OH) in the reaction between the isocyanate group (NCO) of (a1) and the hydroxyl group (OH) of (a2) is the viscosity of the adhesion-imparting agent. From this viewpoint, it is preferably 1.3 / 1 to 3.0 / 1, more preferably 1.5 / 1 to 2.2 / 1. The end groups of the urethane prepolymer are NCO groups at both ends, or one end is an NCO group and the other end is an OH group. From the viewpoint of acrylic plastisol adhesion, both ends are preferably NCO groups. is there.

In order to accelerate the reaction, a known urethanization catalyst may be used. Examples of the urethanization catalyst include metal catalysts (tin-based (trimethyltin laurate, trimethyltin hydroxide, dimethyltin dilaurate, dibutyltin diacetate, dibutyltin dilaurate, stannous octoate, dibutyltin maleate, etc.), lead-based ( Lead oleate, lead 2-ethylhexanoate, lead naphthenate, lead octenoate, etc.), cobalt-based (cobalt naphthenate, etc.), mercury-based (phenylmercuric propionate, etc.)], amine catalyst [triethylenediamine, tetra Methylethylenediamine, tetramethylhexylenediamine, diazabicycloalkene, dimethylaminoethylamine, dimethylaminopropylamine, diethylaminopropylamine, dibutylaminoethylamine, dimethylaminooctylamine, dipropylaminopropyl Pyramine, 2- (1-aziridinyl) ethylamine, 4- (1-piperidinyl) -2-hexylamine, N-methylmorpholine, N-ethylmorpholine, triethylamine, diethylethanolamine, dimethylethanolamine and their organic acids (formic acid) , Phenol, etc.) salts, etc., and combinations of two or more of these.
The amount of the urethanization catalyst used is usually 1% or less, preferably 0.001 to 0.1%, based on the weight of the urethane prepolymer obtained.

  The reaction temperature for producing the urethane prepolymer is preferably 20 to 120 ° C., more preferably 60 to 110 ° C., from the viewpoint of suppressing side reactions. The reaction time is preferably 3 to 10 hours, more preferably 5 to 8 hours, from the viewpoint of suppressing side reactions.

The preferable lower limit of Mn of the urethane prepolymer is 500, more preferably 700, and the preferable upper limit is 8,000, more preferably 5,000. If the Mn is 500 or more, the resin is soft and has a favorable effect on the chipping resistance. If it is 8,000 or less, the atomization (atomization) of the acrylic plastisol paint becomes better and the appearance of the coating film (especially smoothness). Is better.
Further, the free isocyanate group content [NCO% (weight% in terms of solid content)] of the prepolymer is preferably 1 to 20%, more preferably 2 to 15%, from the viewpoint of adhesiveness of the acrylic plastisol. NCO% can be measured or confirmed by titration or infrared absorption spectrum.

  Blocking agents (a3) include lactams (C4-10, such as ε-caprolactam, δ-valerolactam and γ-butyrolactam), oximes [C3-10, such as acetoxime, methyl ethyl ketoxime (MEK oxime) and methyl isobutyl keto. Oximes (MIBK oximes)], amines [C2-20 secondary amines such as aliphatic amines (dimethylamine, diisopropylamine, etc.), alicyclic amines (methylcyclohexylamine, dicyclohexylamine, etc.) and aromatic amines (diphenylamine, etc.) )], Alkylphenols [C7-20, such as cresol, nonylphenol, xylenol and di-t-butylphenol], and mixtures of two or more thereof. Among these, from the viewpoint of adhesiveness and storage stability of acrylic plastisol, one or more selected from the group consisting of lactam, oxime and amine, more preferred is lactam, and particularly preferred is ε-caprolactam. It is.

The blocked polyurethane compound (A) can be obtained by adding and reacting the blocking agent (a3) at any stage of the urethane prepolymer formation reaction.
The addition method includes (1) a method of adding the total amount to the polyol (a1) in advance, (2) a method of adding the total amount in the initial stage of the urethane prepolymer formation reaction, and (3) adding a part in the initial stage of the reaction or in the middle of the reaction. , A method of adding the remainder at the end of the reaction and (4) a method of adding after the end of the reaction. Among these, the method (4) is preferable from the viewpoint of the reproducibility of the reaction.
In the case of the methods (1) to (3), the amount of (a3) added is the hydroxyl group of the polyol (a2) from the number of NCO equivalents of the raw polyisocyanate (a1) from the viewpoint of the storage stability of the acrylic plastisol. It is preferable to use approximately the same equivalent as that obtained by subtracting the number of equivalents. In the case of the method (4), preferably 1 to 2 equivalents, more preferably, from the viewpoint of storage stability with respect to the NCO group of the urethane prepolymer. 1.05 to 1.5 equivalents.
In the methods (2) to (4), the system temperature when (a3) is added is preferably 50 to 110 ° C. from the viewpoint of preventing side reactions. In the above reaction, the urethanization catalyst may be added to accelerate the reaction. The use amount of the urethanization catalyst is usually 10% or less, preferably 5% or less, from the viewpoint of storage stability, based on the weight of the urethane prepolymer.
In the case of (A), a plasticizer described later may be added to adjust the viscosity.

  The adhesion-imparting agent (C) of the present invention comprises a blocked polyurethane compound (A) and a heterocyclic polyamine (B). The blocked NCO group in (A) and the active hydrogen in (B) The equivalent ratio is preferably 90/10 to 25/75, more preferably 80/20 to 40/60, from the viewpoint of adhesion of the acrylic plastisol to the cationic electrodeposition coating surface.

The acrylic plastisol of the present invention comprises an adhesiveness imparting agent (C), an acrylic polymer (D) and a plasticizer (E).
(D) is a single polymer or two or more copolymers of alkyl (meth) acrylate (C1-20) ester, or a copolymer of these monomers with other polymerizable unsaturated group-containing monomers. A polymer is included.
The copolymerization ratio (weight ratio) in the copolymer of (meth) acrylic acid alkyl ester and other polymerizable unsaturated group-containing monomer is preferably 50/50 to 99/1, more preferably from the viewpoint of physical properties of the resin. Is 70/30 to 95/5.

  Examples of (meth) acrylic acid alkyl esters include C4-30, such as methyl (meth) acrylate, -ethyl, -butyl, and -hexyl.

Examples of other polymerizable unsaturated group-containing monomers include the following.
(1) Aromatic unsaturated hydrocarbon (unsaturated hydrocarbon is abbreviated as HC hereinafter)
C8-20, such as styrene, methyl styrene, vinyl toluene, trimethyl styrene, halogenated styrene, t-butyl styrene, amino styrene, p-benzyl styrene, p-phenoxy styrene, oxystyrene (2) aliphatic HC
C2-18 or more, such as alkenes [ethylene, propylene, (iso) butene, pentene, heptene, diisobutylene, octene, dodecene, octadecene, other α-olefins, etc.] and dienes [butadiene, isoprene, 1,4- Pentadiene, 1,6-hexadiene, 1,7-octadiene, etc.]
(3) Alicyclic HC
C4-18 or more, for example (di) cycloalkene [cyclohexene, (di) cyclopentadiene, pinene, limonene, indene, vinylcyclohexene, ethylidenebicycloheptene, etc.]
(4) Amino group-containing (meth) acrylic acid ester C4-30, such as 2-aminoethyl (meth) acrylate, N, N-diethylamino (meth) acrylate (5) 1-4 or more hydroxyl groups in the molecule And compounds having 1 to 4 or more polymerizable unsaturated groups C5 to 600, such as hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, diethylene glycol mono (meth) ) Acrylate, polyethylene glycol (polymerization degree 3-100) mono (meth) acrylate, polypropylene glycol (polymerization degree 3-100) mono (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate 6) α, β-unsaturated dicarboxylic acids or their anhydrides C4-12 dicarboxylic acids such as (anhydrous) maleic acid, fumaric acid, crotonic acid, (anhydrous) itaconic acid (7) α, β-unsaturated Esters of dicarboxylic acids C6-30, such as fumaric acid esters (diethyl fumarate, dioctyl fumarate, etc.)

(8) Other vinyl monomers Nitrile group-containing vinyl monomers [C3-15, such as (meth) acrylonitrile, cyanostyrene, cyanoalkyl (C1-4) acrylate];
Vinyl esters [aliphatic vinyl esters (C4-15, such as vinyl acetate, vinyl butyrate, vinyl propionate, vinyl butyrate, diallyl adipate, isopropenyl acetate, vinyl methoxyacetate), aromatic vinyl esters (C9-20, such as diallyl Phthalate, methyl-4-vinylbenzoate, acetoxystyrene) and the like];
Halogen-containing vinyl monomers (C2-4, such as vinyl chloride, vinylidene chloride);
Vinyl ether {aliphatic vinyl ether [C3-15 vinyl alkyl (C1-10) ether [vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, vinyl butyl ether, vinyl-2-ethylhexyl ether, vinyl-2-chloroethyl ether, etc.] , Vinyl alkoxy (C1-6) alkyl (C1-4) ether [vinyl-2-methoxyethyl ether, methoxybutadiene, vinyl-2-butoxyethyl ether, 3,4-dihydro-1,2-pyran, 2-butoxy -2'-vinyloxydiethyl ether, vinyl-2-ethylmercaptoethyl ether, etc.], poly (2-4) (meth) allyloxyalkane (C2-6) (dialyloxyethane, triaryloxyethane, tetra-allyl Roxyethane, tetraallyloxy Propane, tetraallyloxybutane, tetrametaallyloxyethane, etc.)], aromatic vinyl ethers (C8-20, such as vinylphenyl ether and phenoxystyrene), etc.};

Heterocycle-containing vinyl monomers [pyridine compounds (C7-14, such as 4-vinylpyridine and 2-vinylpyridine), imidazole compounds (C5-12, such as N-vinylimidazole), pyrrole compounds (C6-13, such as N-vinyl) Pyrrole), pyrrolidone compounds (C6-13, such as N-vinyl-2-pyrrolidone), carbazole compounds (C14-20, such as N-vinylcarbazole) and the like];
Sulfo group-containing vinyl monomers [C4-25, such as vinyl ethyl sulfone, divinyl sulfone, divinyl sulfoxide, vinyl sulfonic acid, (meth) allyl sulfonic acid, methyl vinyl sulfosuccinate, styrene sulfonic acid, α-methyl styrene sulfonic acid , Sulfopropyl (meth) acrylate, 2-hydroxy-3- (meth) acryloxypropylsulfonic acid, 2- (meth) acryloylamino-2,2-dimethylethanesulfonic acid, 2- (meth) acryloyloxyethanesulfonic acid 3- (meth) acryloyloxy-2-hydroxypropanesulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, 3- (meth) acrylamide-2-hydroxypropanesulfonic acid, alkyl (C3-18) Allylsulfo Haq acid, and alkali metal (sodium, potassium, etc.) salts thereof];
Vinyl ketone [aliphatic vinyl ketone (C4-25, such as vinyl methyl ketone and vinyl ethyl ketone), aromatic vinyl ketone (C9-21, such as vinyl phenyl ketone), etc.];
Sulfide group-containing monomers (C4-20, such as divinyl sulfide, p-vinyl diphenyl sulfide, and vinyl ethyl sulfide);
Vinylene carbonate, 2-vinyl furan, vinyl phenyl disiloxane, vinyl urethane, etc.

Among these, from the viewpoint of resin physical properties, a homopolymer of methyl (meth) acrylate, a copolymer of methyl (meth) acrylate and the above-mentioned other monomers, more preferably methyl (meth) acrylate A homopolymer of methyl (meth) acrylate and butyl (meth) acrylate.
The monomer can be polymerized by a known method (for example, solution polymerization, emulsion polymerization, suspension polymerization, etc.).

The Mn in (D) is not particularly limited, but is preferably 100,000 to 5,000,000, more preferably 300,000 to 3,000,000 from the viewpoint of resin physical properties.
(D) can use 2 or more types together.

As the plasticizer (E), aromatic carboxylic acid ester [phthalic acid ester (diethyl phthalate (DEP), dibutyl phthalate (DBP), di-2-ethylhexyl phthalate (DOP), dilauryl phthalate, distearyl phthalate, diisononyl phthalate] (DINP), triethylene glycol dibenzoate, etc.], aliphatic carboxylic acid ester [methylacetylricinoleate, di-2-ethylhexyl adipate (DOA), di-2-ethylhexyl sebacate (DOS), adipic acid-propylene glycol polyester 2,2,4-trimethyl 1,3-pentanediol diisobutyrate, etc.], phosphate esters [triphenyl phosphate, tricresyl phosphate, etc.], and mixtures of two or more of these.
Of these, aromatic carboxylic acid esters are preferred from the viewpoint of solubility in the blocked polyurethane compound (A), and di-2-ethylhexyl phthalate (DOP) and diisononyl phthalate (DINP) are more preferred.

  Based on the total weight of (C), (D) and (E), the content of (C) is preferably 1 to 40%, more preferably from the viewpoint of the adhesion of acrylic plastisol to the cationic electrodeposition coating surface. Is from 2 to 30%, and the content of (D) is preferably from 10 to 50%, more preferably from 15 to 40%, from the viewpoint of the viscosity of the acrylic plastisol, and the content of (E) is from the viewpoint of the viscosity of the acrylic plastisol , Preferably 10 to 50%, more preferably 20 to 45%.

  In addition to the above (C), (D) and (E), the acrylic plastisol contains other additives (foaming agent, coloring agent, stabilizer, diluent) as long as the effects of the present invention are not impaired as required And / or fillers). The total amount of the other additives is usually 50% or less, preferably 1 to 40%, based on the total weight of the acrylic plastisol.

  As blowing agents, azo blowing agents (azodicarbonamide, azobisisobutyronitrile, etc.), nitroso blowing agents (dinitrosopentamethylenetetramine, etc.) and hydrazide blowing agents [toluenesulfonyl hydrazide, oxybis (benzenesulfonyl hydrazide) And the like]. The amount of foaming agent used is usually 5% or less, preferably 0.1 to 2%, based on the total weight of the acrylic plastisol.

Examples of the colorant include inorganic pigments, organic pigments, and dyes.
Inorganic pigments include white pigments (titanium oxide, lithopone, lead white, zinc white, etc.), cobalt compounds (aureolin, cobalt green, cerulean blue, cobalt blue, cobalt violet, etc.), iron compounds (iron oxide, bitumen, etc.), Examples thereof include chromium compounds (chromium oxide, lead chromate, barium chromate, etc.), sulfides (cadmium sulfide, cadmium yellow, ultramarine, etc.), and mixtures thereof.

Organic pigments include azo pigments (azo lake, monoazo, disazo, chelate azo), polycyclic pigments (benzimidazolone, phthalocyanine, quinacridone, dioxazine, isoindolinone, thioindigo, and perylene. Quinophthalone, anthraquinone, etc.), and mixtures thereof.
As dyes, azo, anthraquinone, indigoid, sulfide, triphenylmethane, pyrazolone, stilbene, diphenylmethane, xanthene, alizarin, acridine, quinoneimine, thiazole, methine, nitro Nitroso, aniline, and mixtures thereof. The amount of the colorant used is usually 5% or less, preferably 0.1 to 2%, based on the total weight of the acrylic plastisol.

  Stabilizers include metal soaps (calcium stearate, aluminum stearate, etc.), inorganic acid salts (dibasic phosphite, dibasic sulfate, etc.) and organometallic compounds (dibutyltin dilaurate, dibutyltin maleate) Etc.). The amount of stabilizer used is usually 10% or less, preferably 0.2-5%, based on the total weight of the acrylic plastisol.

  Diluents include xylene and mineral terpenes. The amount of diluent used is usually 20% or less, preferably 5 to 15%, based on the total weight of the acrylic plastisol.

  As fillers, inorganic fillers (calcium carbonate, talc, clay, diatomaceous earth, silicic acid, silicate, kaolin, asbestos, mica, glass fiber, glass balloon, carbon fiber, metal fiber, ceramic whisker, titanium whisker) And organic fillers [cellulose powder, powder rubber, organic crosslinked fine particles (epoxy, urethane, etc.), urea, etc.]. The amount of the filler used is usually 40% or less, preferably 1 to 35% from the viewpoint of the viscosity of the acrylic plastisol based on the total weight of the acrylic plastisol.

A formulation example of acrylic plastisol is as follows (% indicates% by weight).
-Adhesiveness imparting agent (C) [Solid content conversion] 2-30%
-Acrylic polymer (D) 15-40%
・ Plasticizer (E) 20-45%
・ Other additives (foaming agents, fillers, etc.) 1-40%

The acrylic plastisol of the present invention can be produced by a usual method (for example, a method described in JP-A-2-14271). For example, the above components are charged, disperse, ball mill, steel mill, pebble mill, attritor, sand mill, sand grinder, pot mill, planetary mixer, kneader, glen mill, roll, and universal mixer [(D) dispersibility and simple manufacturing. From the viewpoint of properties, it is preferable that the dispersion is uniformly mixed and stirred with a disper] or the like. There are no particular restrictions on the order in which the components are charged, but from the viewpoint of uniform mixing of (C), (D) and (E), it is preferable to first mix (C), (D) and (E). Thereafter, other additives are added and mixed.
The mixing temperature is usually 0 to 40 ° C. (preferably 10 to 30 ° C.), and the mixing time is usually 20 minutes to 1.5 hours (preferably 30 minutes to 1 hour).

  The storage stability (retention rate of initial viscosity during production) of the acrylic plastisol of the present invention is preferably 30% or less, and more preferably 0 to 20%, from the viewpoint of paintability.

The acrylic plastisol of the present invention can be applied to various undercoating surfaces applied to various metal (especially steel) surfaces, but can be advantageously applied to cationic electrodeposition coating surfaces from the viewpoint of adhesion of acrylic plastisols.
The coating amount of the acrylic plastisol is preferably 500 to 3,000 g / m ² from the viewpoint of chipping resistance, and the coating film thickness is preferably 0.2 to ² mm from the viewpoint of chipping resistance. In addition, the film thickness at the time of application | coating and the film thickness after the heat processing mentioned later hardly change.
Examples of the application method include brush coating, spatula coating, roller coating, and airless spray coating, and airless spray coating is preferred from the viewpoint of coating efficiency and coating with a high viscosity paint.
Although heat treatment is performed after coating, the heat treatment temperature in the present invention may be lower than the conventional heat treatment temperature (140 to 180 ° C.), and preferably 110 ° C. or more and less than 140 ° C. from the viewpoint of adhesiveness and curability of acrylic plastisol. Further, it is preferably 120 to 135 ° C., and the heat treatment time may be short, and from the same viewpoint as described above, it is preferably 10 to 40 minutes, more preferably 20 to 30 minutes.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by this. In the following, “parts” means parts by weight, and “%” means% by weight.

[Production Example of Blocked Polyurethane (A)]
Production Example 1
A reaction vessel equipped with a stirrer was charged with 108.2 parts of TDI and 621.6 parts of a glycerin PO adduct (Mn 3,000, the same shall apply hereinafter), and stirred and mixed in a nitrogen stream at 80 to 90 ° C. for 5 hours. Reaction was performed to obtain a urethane prepolymer having NCO% of 3.6. Next, after adding 70.2 parts of ε-caprolactam and further reacting at the same temperature for 3 hours, it was confirmed by titration that the NCO group had disappeared. Next, 200 parts of DINP was added to obtain a blocked polyurethane solution (A1) having a solid content of 80% and a blocked apparent NCO% (hereinafter abbreviated as latent NCO%) 2.6.

Production Example 2
A reaction vessel similar to Production Example 1 was charged with 135.7 parts of IPDI, 611.2 parts of PO adduct of glycerin and 0.04 part of dibutyltin dilaurate, and stirred and mixed in a nitrogen stream at 80 to 90 ° C. for 3 hours. The reaction was performed to obtain a urethane prepolymer having NCO% of 3.4. Subsequently, 53.2 parts of methyl ethyl ketone oxime was added and reacted at 50 to 70 ° C. for 1 hour, and it was confirmed by titration that the NCO group had disappeared. Next, 200 parts of DINP was added to obtain a blocked polyurethane solution (A2) having a solid content of 80% and a latent NCO% of 2.6.

Production Example 3
In a reaction vessel similar to Production Example 1, 134.7 parts of IPDI, 607.0 parts of glycerin PO adduct and 0.04 part of dibutyltin dilaurate were charged and stirred and mixed in a nitrogen stream at 80 to 90 ° C. for 3 hours. Reaction was performed to obtain a urethane prepolymer having an NCO% of 3.4. Subsequently, 58.3 parts of 3,5-dimethylpyrazole was added and further reacted at 50 to 70 ° C. for 1 hour, and it was confirmed by titration that the NCO group had disappeared. Next, 200 parts of DINP was added to obtain a blocked polyurethane solution (A3) having a solid content of 80% and a latent NCO% of 2.6.

Production Example 4
In the same reaction vessel as in Production Example 1, 110.4 parts of TDI and 634.4 parts of PO adduct of glycerin were charged, stirred and mixed under a nitrogen stream, reacted at 80 to 90 ° C. for 5 hours, and NCO% 3.6 The urethane prepolymer was obtained. Next, 55.2 parts of methyl ethyl ketone oxime was added and further reacted at 50 to 70 ° C. for 1 hour, and it was confirmed by titration that the NCO group had disappeared. Next, 200 parts of DINP was added to obtain a blocked polyurethane solution (A4) having a solid content of 80% and a latent NCO% of 2.6.

Production Example 5
A reaction vessel similar to Production Example 1 was charged with 109.6 parts of TDI and 629.9 parts of a glycerin PO adduct, stirred and mixed in a nitrogen stream, reacted at 80 to 90 ° C. for 5 hours, and NCO% 3.6 The urethane prepolymer was obtained. Next, after adding 60.5 parts of 3,5-dimethylpyrazole and further reacting at 50 to 70 ° C. for 1 hour, it was confirmed by titration that the NCO group had disappeared. Next, 200 parts of DINP was added to obtain a blocked polyurethane solution (A5) having a solid content of 80% and a latent NCO% of 2.6.

Example 1
(A1) "Zeon F-320" [manufactured by Nippon Zeon Co., Ltd., methyl methacrylate homopolymer (powder with Mn 3 million, average particle size 1μ) to a mixture of 20 parts and 0.8 parts of aminoethylpiperazine ,same as below. ] 60 parts, “Hakuenka CC-R” [Shiraishi Kogyo Co., Ltd., surface-treated ultrafine calcium carbonate (average particle size 0.08 μ), and so on. 60 parts and 60 parts of DINP were added and uniformly kneaded with a disper to prepare an acrylic plastisol, and performance evaluation was performed by the method described later.
The initial viscosity of the plastisol was 115 Pa · s / 25 ° C., and the viscosity after storage at 35 ° C. for 10 days was 132 Pa · s / 25 ° C. Also, the adhesion and water-resistant adhesion were extremely good. The results are shown in Table 1.

Example 2
60 parts of “Zeon F-320”, 60 parts of “White Glossy CC-R” and 68 parts of DINP are added to a mixture of 12 parts of (A1) and 0.8 parts of aminoethylpiperazine, and the same as in Example 1. Acrylic plastisol was prepared and performance was evaluated. The results are shown in Table 1.

Example 3
In Example 1, an acrylic plastisol was prepared and evaluated for performance in the same manner as in Example 1 except that the same amount of (A2) was used instead of (A1). The results are shown in Table 1.

Example 4
In Example 1, an acrylic plastisol was prepared and evaluated for performance in the same manner as in Example 1 except that the same amount of (A3) was used instead of (A1). The results are shown in Table 1.

Example 5
In Example 1, an acrylic plastisol was prepared and evaluated for performance in the same manner as in Example 1 except that the same amount of bis (aminopropyl) piperazine was used instead of aminoethylpiperazine. The results are shown in Table 1.

Comparative Example 1
In Example 1, an acrylic plastisol was prepared and evaluated for performance in the same manner as in Example 1 except that the same amount of adipic acid dihydrazide was used instead of aminoethylpiperazine. The results are shown in Table 2. From this result, it can be seen that the adhesiveness is remarkably inferior to each example.

Comparative Example 2
In Example 1, an acrylic plastisol was prepared and evaluated for performance in the same manner as in Example 1 except that (A4) was used instead of (A1) and the same amount of adipic acid dihydrazide was used instead of aminoethylpiperazine. The results are shown in Table 2. This result shows that chipping resistance is inferior to each example.

Comparative Example 3
In Example 1, an acrylic plastisol was prepared and evaluated for performance in the same manner as in Example 1 except that (A5) was used instead of (A1) and the same amount of adipic acid dihydrazide was used instead of aminoethylpiperazine. The results are shown in Table 2. This result shows that chipping resistance is inferior to each example.

The specific test method used for the performance evaluation is as follows.
(1) Initial viscosity Viscosity immediately after creation of acrylic plastisol [BH viscometer, manufactured by Tokyo Keiki Co., Ltd., unit is Pa · s / 25 ° C.].
(2) Viscosity after storage After preparation of acrylic plastisol, 90 g in a glass cylindrical container having an inner diameter of about 4 cm and a height of about 8 cm and stored at 35 ° C. for 10 days [measurement conditions, unit is the above (1) Same as. ] Measured.
(3) Storage stability The rate of increase in viscosity (%) after storage relative to the initial viscosity at the time of acrylic plastisol creation was calculated. The smaller the value, the better the storage stability.
(4) Curability A frame is attached to the coated surface of the epoxy resin-based cationic electrodeposition coated steel sheet so that the internal volume is 50 × 20 × 1 mm, and the acrylic plastisol is spatula so that the film thickness is 1 mm. Painted. After the heat treatment at 130 ° C. for 20 minutes, the degree of curing of the coating film was judged by finger touch according to the following criteria.
◎ No tack, good curability ○ Slightly tack but hard enough for practical use △ Has tack, insufficient curability x Uncured

(5) Adhesive Acrylic plastisol is spatally applied to the end of the 100 × 25 × 1 mm epoxy resin cationic electrodeposition coated steel sheet (area approximately 2 × 2 cm ² ) so that the film thickness after crimping is 1 mm. The other same electrodeposition coating plate was pressure-bonded. After heat treatment at 130 ° C. for 20 minutes in that state, the ends of the two steel plates were pulled in the shearing direction at a pulling speed of 50 mm / min, and the adhesion to the epoxy resin-based cationic electrodeposition coating surface was evaluated from the broken state. . Judgment criteria are as follows.

○ Cohesive failure △ Cohesive failure and interface peeling coexist × Interface peeling

(6) Water-resistant adhesiveness The same test piece as (5) above was prepared, and after being baked at 130 ° C for 20 minutes, it was then immersed in warm water at 40 ° C for 3 days. Sex was evaluated according to the same criteria as (5).
(7) Chipping resistance A 100x100x0.8mm epoxy resin-based cationic electrodeposition coated steel sheet is coated with acrylic plastisol at a thickness of 400μ and baked at 130 ° C for 20 minutes. 3 types of M-4 brass hex nuts defined in JIS B-1181 are dropped from a height of 2 m onto a sample plate having an angle of 45 ° with respect to the drop direction of the nut through a cylinder having a tube diameter of 20 mm. The total weight (kg) of the nut until the scratch on the coating reached the metal surface was measured.

  The acrylic plastisol using the adhesiveness-imparting agent of the present invention is excellent in storage stability, strongly adheres to a metal coating surface at a relatively low temperature, and has excellent chipping resistance, so various adhesives, sealants, paints, etc. It can be applied to industrial applications, and is particularly useful as a body sealer and undercoat material for automobile bodies that have been subjected to cationic electrodeposition coating in the automobile industry.

Claims (7)

An adhesiveness-imparting agent (C) for acrylic plastisol, comprising a blocked polyurethane compound (A) and a heterocyclic polyamine (B). The adhesiveness-imparting agent (C) according to claim 1, wherein (B) is one or more heterocyclic polyamines selected from the group consisting of piperazine and aminoalkyl-substituted piperazine. The adhesiveness imparting agent (C) according to claim 1 or 2, wherein (A) is a polyurethane compound blocked with one or more blocking agents selected from the group consisting of lactam, oxime and amine. The adhesiveness imparting agent (C) according to any one of claims 1 to 3, wherein the equivalent ratio of the blocked NCO group in (A) to the active hydrogen in (B) is 90/10 to 25/75. An acrylic plastisol comprising the adhesion-imparting agent (C) according to any one of claims 1 to 4, an acrylic polymer (D), and a plasticizer (E). 6. (C) is 1 to 40%, (D) is 10 to 50%, and (E) is 10 to 50% based on the total weight of (C), (D) and (E). Acrylic plastisol. The acrylic plastisol according to claim 5 or 6, further comprising an additive selected from the group consisting of a foaming agent, a colorant, a stabilizer, a diluent and a filler.