JPH08231681A - Tackifier - Google Patents

Abstract

PURPOSE: To improve the compatibility with a plasticizer, water resistance, yellowing resistance and low-temperature adhesiveness by using as the constituent a blocked polyisocyanate having a specified amount of the isocyanato groups blocked with an alkylphenol compound. CONSTITUTION: 5-70% of the isocyanato groups of a polyisocyanate are blocked with an alkylphenol compound, and the remaining groups are blocked with a blocking agent other than an alkylphenol. The blocking is effected at -20 to 150 deg.C in the presence of catalysts comprising an organometallic salt of tin, zinc or lead and a tertiary amine, etc. The blocked polyisocyanate is mixed with a plasticizer in an amount of 20-80wt.% based on the total to give a tackifier. This tackifier is added to a vinyl chloride polymer paste resin, which is mixed with a diluent, a filler, a thickening agent, a coloring agent, etc., to give a plastisol composition. This composition is applied to an object and baked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastisol adhesiveness imparting agent, and more particularly to an adhesiveness imparting agent for firmly adhering plastisol to a metal coated surface in the automobile industry and the like.

[0002]

2. Description of the Related Art For plastisols such as vinyl chloride type plastisols, a method of adding an adhesiveness-imparting agent is used in order to improve the adhesiveness to a metal coated surface. For example, block polyisocyanate, polyamidoamine compound and the like are used as the adhesion imparting agent constituent component. As these techniques, for example, in JP-B-59-52901, a blocked urethane prepolymer with a blocking agent of a urethane prepolymer having an isocyanate group from a polyol and an organic diisocyanate and a polyamide compound are disclosed in JP-B-62-62. In JP 41278, a long chain alkylphenol block of a diisocyanate polymer having an average molecular weight of 1,000 to 10,000 is disclosed in JP-A-1-170.
No. 633 discloses a blocked urethane prepolymer of polyamine and isocyanurate type polyisocyanate,
Japanese Unexamined Patent Publication (Kokai) No. 3-29257 discloses a polymer of aromatic diisocyanate randomly blocked with two or more alkylphenol blocking agents.

Although polyamidoamine compounds are excellent in the effect of imparting adhesiveness, they have problems in water resistance, yellowing resistance and the like. Although the block polyisocyanate is excellent in water resistance and the like, its compatibility with vinyl chloride plasticizers is poor and its adhesion at low temperatures is poor.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a plastisol adhesion-imparting agent which is excellent in water resistance, yellowing, and low-temperature adhesion.

[0005]

Means for Solving the Problems As a result of sincere investigations by the present inventors, the compatibility of a block polyisocyanate with a plasticizer by using an alkylphenol and another blocking agent together as a block agent of the block polyisocyanate Therefore, the present invention has been completed and the present invention has been completed.

The present invention has five or more isocyanate groups 70
% Or less is a plastisol adhesiveness-imparting agent characterized by containing a block polyisocyanate blocked with an alkylphenol compound, and the block polyisocyanate is preferably an aliphatic and / or alicyclic diisocyanate. . Hereinafter, the present invention will be described in detail.

The polyisocyanate used in the present invention can be obtained, for example, from diisocyanate. As the aromatic diisocyanate, tolylene diisocyanate,
The diphenylmethane diisocyanate, naphthylene diisocyanate, xylylene diisocyanate, and aliphatic diisocyanate preferably have 4 to 30 carbon atoms, and the alicyclic diisocyanate preferably have 8 to 30 carbon atoms. , For example, 1,4-tetramethylene diisocyanate, 1,5-pentamethylene diisocyanate,
1,6-hexamethylene diisocyanate, 2,2,4
(Or 2,4,4) -trimethyl-1,6-hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) -cyclohexane, 4,4'-dicyclohexyl Examples include methane diisocyanate, xylylene diisocyanate, and tetramethyl xylene diisocyanate. Among them, 1,6 in terms of appearance and industrial availability
-Hexamethylene diisocyanate (hereinafter referred to as HMDI) and isophorone diisocyanate (hereinafter referred to as IPDI) are preferable. These may be used alone or in combination of two or more.

Polyisocyanates obtained from these diisocyanates include urethane-modified polyisocyanates obtained by reacting with active hydrogen compounds, biuret-type polyisocyanates, and isocyanurate-type polyisocyanates obtained by polymerization of isocyanate groups. Isocyanate, etc. These are polyisocyanates from which diisocyanate has been removed and are substantially free of diisocyanate.

The urethane-modified polyisocyanate is obtained by reacting a diisocyanate with a compound having two or more active hydrogens in the molecule. Compounds having such active hydrogen include low molecular weight active hydrogen compounds and high molecular weight active hydrogen compounds. As the low molecular weight active hydrogen compound, ethylene glycol, 1,2- or 1,3-bromopyrene glycol, 1,3- or 1,4- or 2,3-butylene glycol, 1,6-hexanediol, neopentyl Examples include glycol, 2-methyl-2,4-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, trimethylolpropane, glycerin, and pentaerythritol.

Examples of the high molecular weight active hydrogen compound include aliphatic hydrocarbon polyols, polyether polyols, polyester polyols and epoxy resins. Examples of the aliphatic hydrocarbon polyols include terminal hydroxylated polybutadiene and hydrogenated products thereof. As the polyether polyols, for example, polyether polyols obtained by adding a single or a mixture of polyhydric alcohols such as glycerin and propylene glycol to ethylene oxide, and alkylene oxide such as propylene oxide.
Polytetramethylene glycols, polyether polyols obtained by further reacting alkylene oxide with a polyfunctional compound such as ethylenediamine and ethanolamine, and a so-called polymer obtained by polymerizing acrylamide or the like using these polyethers as a medium Polyols and the like are included.

As the polyester polyols, for example, a dibasic acid alone selected from the group of carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid and terephthalic acid. Alternatively, it can be obtained by a condensation reaction of a mixture with a polyhydric alcohol selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, glycerin and the like, alone or in a mixture.

Further, for example, polycaprolactones obtained by ring-opening polymerization of ε-caprolactone using a polyhydric alcohol can be mentioned. Epoxy resins include novolac type, β-methyl epichloro type, cyclic oxirane type, glycidyl ether type, glycol ether type, epoxy type of aliphatic unsaturated compound, epoxidized fatty acid ester type, polycarboxylic acid ester type, aminoglycidyl type. Type, halogenated type, resorcin type and the like.

A catalyst is used in the isocyanurate-forming reaction for obtaining an isocyanurate type polyisocyanate. The catalyst used here is generally preferably basic, for example, tetramethylammonium, tetraalkylammonium hydroxide such as tetraethylammonium and organic weak acid salts such as acetic acid and capric acid, such as trimethylhydroxypropylammonium and trimethyl. Hydroxyethylammonium hydroxides such as hydroxyethylammonium, triethylhydroxypropylammonium and triethylhydroxyethylammonium, weak organic acid salts such as acetic acid and capric acid, and alkyl metal salts of alkylcarboxylic acids such as tin, zinc and lead, for example, Metal alcoholates such as sodium and potassium, aminosilyl group-containing compounds such as hexamethyldisilazane, Mannich bases, secondary amines and epoxies Combination with compounds, for example, a phosphorus-based compounds such as tributyl phosphine.

The catalyst concentration is selected from the range of 10 ppm to 1.0% based on the isocyanate compound. The reaction may or may not use a solvent. If a solvent is used, it should be inert to the isocyanate groups. The reaction temperature is generally 20 to 160 ° C, preferably 40 to 130 ° C. The reaction end point varies depending on the polyhydric alcohol used, but the yield is about 30% or more.

When the reaction reaches the target yield, the catalyst is deactivated by, for example, sulfonic acid, phosphoric acid or the like to stop the reaction. Unreacted diisocyanate and solvent can be removed to obtain an isocyanurate type polyisocyanate having an isocyanurate structure. Further, the urethane-forming reaction of the low-molecular weight active hydrogen compound and diisocyanate may be carried out prior to or simultaneously with the isocyanurate-forming reaction. In addition to the above, the low-molecular weight active hydrogen compound includes monoalcohols such as methanol, ethanol, butanol, heptanol, 2-ethylhexanol, nonanol, decanol, undecanol, and tridecanol having 1 to 13 carbon atoms.

The isocyanate group of the polyisocyanate thus obtained is reacted with a blocking agent to obtain a blocked polyisocyanate. As a blocking agent,
Alkylphenol type, phenol type, active methylene,
Examples include mercaptan-based, acid amide-based, acid imide-based, imidazole-based, urea-based, oxime-based, amine-based, imide-based, and pyrazole-based compounds. Specifically, (1) alkylphenol-based; mono- and dialkylphenols having an alkyl group having 4 or more carbon atoms as a substituent, such as n-propylphenol, i-propylphenol, n-butylphenol, sec- Monoalkylphenols such as butylphenol, t-butylphenol, n-hexylphenol, 2-ethylhexylphenol, n-octylphenol, n-nonylphenol, di-n-propylphenol, diisopropylphenol, isopropylcresol, di-n-butylphenol, di- t-butylphenol, di-sec-
Butylphenol, di-n-octylphenol, di-
Dialkylphenols such as 2-ethylhexylphenol and di-n-nonylphenol, (2) phenolic compounds; phenol, cresol, ethylphenol, styrenated phenol, hydroxybenzoic acid ester, etc.
(3) Active methylene type; dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, acetylacetone, etc. (4) Mercaptan type; butyl mercaptan, dodecyl mercaptan, etc., (5) Acid amide type; acetanilide, acetic amide , Ε-caprolactam, δ-
Valerolactam, γ-butyrolactam, etc., (6) acid imide type; succinimide, maleic acid imide, etc., (7) imidazole type; imidazole, 2-methylimidazole, etc., (8) urea type; urea, thiourea, ethylene Urea, etc.
(9) oxime system; formaldoxime, acetoaldoxime, acetoxime, methylethylketoxime, cyclohexanone oxime, etc. (10) amine system;
Diphenylamine, aniline, carbazole, etc. (1
1) imine type; ethyleneimine, polyethyleneimine, etc., (12) bisulfite; sodium bisulfite, etc., (13)
Pyrazoles; pyrazole, 3-methylpyrazole,
3,5-dimethylpyrazole and the like.

In the present invention, not less than 5% and not more than 70% of the isocyanate groups of the polyisocyanate are blocked with the alkylphenol compound. If it is less than 5%, the compatibility of the block polyisocyanate with the plasticizer is insufficient, and 7
If it exceeds 0%, the function of the block polyisocyanate blocked with a blocking agent other than the alkylphenol compound such as low temperature adhesion cannot be exhibited. Examples of the blocking agent for the remaining isocyanate group that is not blocked by the alkylphenol compound include compounds other than the above-mentioned alkylphenol compounds, but phenol compounds, oxime compounds,
Acid amide type and active methylene type are preferable, and styrenated phenol, acetoxime, methyl ethyl ketoxime, ε-caprolactam, ethyl acetoacetate and ethyl malonate are particularly preferable, and two or more kinds may be mixed.

The blocking reaction of two or more kinds of blocking agents, which essentially requires an alkylphenol compound, may be carried out simultaneously or sequentially. Alternatively, the blocks may be separately formed and then mixed. The reaction between the polyisocyanate and the blocking agent can be carried out with or without the presence of a solvent. When using a solvent, it is necessary to use a solvent which is inactive to the isocyanate group.

In the blocking reaction, an organic metal salt of tin, zinc, lead or the like and a tertiary amine may be used as a catalyst. The reaction can be generally carried out at -20 to 150 ° C, preferably 0 to 100 ° C. If the temperature is 100 ° C. or higher, a side reaction may occur. On the other hand, if the temperature is too low, the reaction rate becomes slow, which is disadvantageous.

The block polyisocyanate can be used in combination with a mono- or polyamidoamine compound having an active hydrogen-containing amino group, a compound such as polyamine, and a block polyisocyanate reaction accelerator. The amine value of the mono- or polyamide compound is 30 or more, preferably 100 to 4
50. If the amine value is less than 30, the compatibility will decrease. The molecular weight is 200-5000, preferably 500-
It is 3000.

Examples of the polyamine include aliphatic compounds,
Alicyclic polyamines such as ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, and cyclohexanediamine, and aromatic polyamines such as xylylenediamine, tolylenediamine, and phenylenediamine. Examples of the block polyisocyanate reaction accelerator include, as an alkali metal compound, a fatty acid having 8 to 18 carbon atoms, an alkyl sulfuric acid, an alkyl sulfonic acid, or a potassium salt or sodium salt of a polyoxyethylene adduct thereof, and the like. Inorganic metal compounds such as lead white, basic lead silicate, tribasic lead sulfate, tribasic lead phosphite, silica gel co-precipitated lead silicate, zinc white, fatty acids having 2 to 18 carbon atoms and cadmium, barium, There are metal salts of calcium, zinc, lead, tin, magnesium and the like, and two or more kinds can be used in combination.

The block polyisocyanate is diluted with a plasticizer to serve as an adhesion promoter. The plasticizer is not particularly limited as long as it is used for vinyl chloride polymers, and examples thereof include di-n-butyl phthalate, di-n-octyl phthalate, and di-2-ethylhexyl phthalate. (Hereinafter referred to as DOP), diisooctyl phthalate,
Phthalates such as diisodecyl phthalate, butylbenzyl phthalate and di-2-ethylhexyl isophthalate, di-2-ethylhexyl adipate, n-decyl adipate, diisodecyl adipate, di-2-ethylhexyl azelate, sebacine Acid dibutyl, sebacic acid di-2
-Fatty acid ester such as ethylhexyl, tributyl phosphate, tri-2-ethylhexyl phosphate, phosphoric acid-2-
There are phosphoric ester type such as ethylhexyl diphenyl and tricresyl phosphate, epoxidized soybean oil, epoxy type such as epoxidized tall oil fatty acid-2-ethylhexyl and the like, and one kind or a mixture of two or more kinds of them may be used. You can Phthalates are widely used.

The concentration of the plasticizer in the adhesion-imparting agent is 20-80.
% Is preferred. Such an adhesion promoter is added to the vinyl chloride polymer composition dispersed in the plasticizer. The vinyl chloride-based polymer is produced by emulsion polymerization of vinyl chloride or a mixture of vinyl chloride and a comonomer copolymerizable therewith in the presence of an emulsifier and a water-soluble polymerization initiator.
Below, preferably about 0.05 ~ 3μ base resin,
Alternatively, it is produced by a fine suspension polymerization method in which, in the presence of a dispersant and an oil-soluble polymerization initiator, all or part of vinyl chloride or a mixture of vinyl chloride and a comonomer copolymerizable therewith is mechanically finely dispersed and then polymerized. It is a paste resin or a resin for mixing paste resin. Further, a vinyl chloride resin or a vinyl chloride copolymer resin having a large particle size produced by ordinary suspension polymerization may be used in combination within a range that does not adversely affect the viscosity, fluidity, processability and the like of the paste sol. Examples of comonomers copolymerizable with vinyl chloride include vinyl esters such as vinyl acetate, vinyl propionate and vinyl laurate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 3 -Acrylic acid esters such as hydroxybutyl acrylate, methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, dibutyl maleate, diethyl male Maleates such as acrylate and ethyl 2-hydroxyethyl maleate, and fumaric acid esters such as dibutyl fumarate and diethyl fumarate. , Vinyl methyl ether, vinyl butyl ether, vinyl hydroxybutyl ether, vinyl ethers of vinyl octyl ether, acrylonitrile, vinyl cyanides such as methacrylonitrile, ethylene, propylene, styrene and the like α
-Vinylidene halides or vinyl halides other than vinyl chloride such as olefins, vinylidene chloride and vinyl bromide, and n-methylol-acrylamide.

In the final plastisol composition, diluents, fillers, thickeners, colorants and the like can be added in addition to the above components.
Aliphatic solvents such as diluents, such as hexane, heptane, octane-nonane, decane, etc., and naphthene hydrocarbon solvents such as cyclohexane and methylcyclohexane,
Dimethylcyclohexane, diethylcyclohexane, etc.,
As the aromatic solvent, toluene, xylene, ethylbenzene, Soleveso # 100 (manufactured by Esso Chemical), Solvesso # 150 (manufactured by Esso Chemical), and as the filler, for example, light or heavy calcium carbonate, talc, diatomaceous earth,
Examples thereof include inorganic fillers such as kaolin and barium sulfate, and organic fillers such as cellulose powder, powder rubber and recycled rubber. Examples of the thickener include anhydrous silica, organic bentonite, metal soap and the like.

The coating amount of the plastisol composition thus prepared is 150 to 3000 g / m ² , and the coating film thickness is preferably 0.15 to 3 mm. Baking is performed after coating.
In that case, the temperature is 110 to 150 ° C., and the baking time is 20 to
40 minutes is preferred. The coating method is, for example, spray coating,
Methods such as brush coating, dipping, pouring, pouring, and air spray can be used.

The adhesiveness-imparting agent of the present invention is added to a plastisol composition and applied to various industrial uses as a sealing agent, an undercoating agent and a chipping-resistant agent. Particularly, in the automobile industry, for example, polyester is used on a car body that has been subjected to cationic electrodeposition coating for the purpose of rust prevention, buffering at the time of contact with flying pebbles, and for the purpose of sealing pinholes and gaps. Resin paint, epoxy resin paint,
Used as a base paint for acrylic resin paints.

[0027]

EXAMPLES "Parts" in Examples and Comparative Examples are based on weight. The plastisol was prepared as follows and the adhesiveness was evaluated. The composition of the plastisol is “vinyl chloride straight resin (Kanefuchi Chemical Industry's trade name“ Kanevinyl PSL-1
0 ") 70 parts, vinyl chloride copolymer (Kanefuchi Chemical Industry's trade name" Kanevinyl PCH-12 ") 30 parts, dioctyl phthalate 110 parts, calcium carbonate 150 parts, dibasic lead phosphite 3 parts, polyamidoamine (Henkel brand name Versamide 140) 3 parts, adhesiveness imparting agent 3 parts ",
With a cation electrodeposition coated plate as the adherend, the sol thickness is 0.5 m
m, after baking at 120 ° C. for 30 minutes, the shear adhesive strength was measured at a pulling speed of 5 mm / minute.

The evaluation was made such that 15 kg / cm ² or more was evaluated as ◯ and less than 15 kg / cm ² was evaluated as x.

[0029]

Example 1 100 parts of isocyanurate type polyisocyanate compound (trade name "Duranate TPA" manufactured by Asahi Kasei Co., Ltd.) using HMDI as a raw material in a four-necked flask equipped with a stirrer, a thermometer and a reflux condenser. To DOP182
65 parts of nonylphenol was added to
The temperature was kept at 2 ° C for 2 hours. The temperature is lowered and 25 parts of methyl ethyl ketoxime (hereinafter referred to as MEK oxime) is added to 40 to 5 parts.
In the range of 0 ° C., it was added over 1 hour. It was confirmed by infrared spectrum that the absorption of the isocyanate group had disappeared, and a block polyisocyanate was obtained. This solution at 20 ℃, 2
Even after standing for 4 hours, it was a uniform transparent solution and had good compatibility. In this case, the ratio of nonylphenol-blocked isocyanate groups to the total isocyanate groups is 5
It was 0%.

[0030]

Examples 2-3, Comparative Examples 1-2 The same procedure as in Example 1 was carried out except that the amounts of methylethylketoxime and nonylphenol added were changed to those shown in Table 1. The results are shown in Table 1.

[0031]

[Table 1]

[0032]

Although only a limited number of block polyisocyanates can be used so far, the present invention provides a variety of plastisol composition designs due to the improved compatibility of plastisol plasticizers and block polyisocyanates. Depending on the application, for example, the adhesiveness in low temperature baking is improved,
Yellowing can be reduced.

Claims (2)

[Claims] 1. An adhesiveness-imparting agent for plastisol, characterized in that 5 to 70% of an isocyanate group contains a block polyisocyanate blocked with an alkylphenol compound. 2. The plastisol adhesion promoter according to claim 1, wherein the block polyisocyanate is derived from an aliphatic and / or alicyclic diisocyanate.