JPH0286641A - Plastisol composition - Google Patents

Abstract

PURPOSE:To obtain a plastisol composition adapted so as to firmly bond to a metallic surface at a relatively low temperature within a short time and improved in storage stability by mixing a vinyl chloride (co)polymer with a plasticizer and a specified tackifier. CONSTITUTION:A blocked urethane prepolymer (a) is obtained by reacting an NCO-containing urethane prepolymer obtained from an organic diisocyanate component (i) comprising at least 50wt.% alpha,alpha,alpha'alpha'-tetramethylxylylene diisocyanate and other organic diisocyanates (e.g., hexamethylene diisocyanate) and a polyol component (ii) of an MW of 500-3000 per OH group, in an equivalent ratio of the NCO groups of component (i) to the OH groups of component (ii) of 1.3-3.0, with a blocking agent (iii) comprising an oxime and/or a lactam. 10-50wt.% vinyl chloride (co)polymer is mixed with 10-50wt.% plasticizer (e.g., dioctyl phthalate), 0.5-20wt.% tackifier comprising component (a) and an amino mono- or poly-amide compound (b) of an amine value >=90, and 0-70wt.% additive.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to plastisol compositions. More specifically, the present invention relates to a vinyl chloride plastisol composition that firmly adheres to metal painted surfaces at relatively low temperatures and in a short period of time, and that has excellent storage stability.

[Prior Art] Conventionally, there is a vinyl chloride plastisol composition containing an adhesion imparting agent consisting of a blocked urethane prepolymer using an organic polyisocyanate such as tolylene diisocyanate and an active amino group-containing mono- or polyamide compound. (For example, Japanese Patent Publication No. 5B-52901).

[Problems to be Solved by the Invention] However, the above composition cannot be used at relatively low temperatures for a short period of time (for example, 1
There is a problem that sufficient adhesion cannot be obtained by heat treatment at 20° C. for 20 minutes.

[Means for Solving the Problems] The present inventors have conducted intensive studies on vinyl chloride plastisol compositions that have sufficient adhesion and excellent plastisol storage stability when heated at relatively low temperatures and in a short time, and have developed the present invention. reached.

That is, the present invention provides a plastisol composition comprising a vinyl chloride polymer or copolymer (A), a plasticizer (B), and an adhesion-imparting agent (C) as essential components, wherein the adhesion-imparting agent (C) is (1 ) Blocked urethane prepolymer (b) with a blocking agent of urethane prepolymer (a) having an incyanate group made from an organic diisocyanate containing α, α, α′, α′-tetramethylxylylene diisocyanate and polyols and (2) an active amine group-containing mono- or polyamide compound (C).

The blocked urethane prepolymer (b) used as a part of the adhesion imparting agent in the present invention includes polyols having an average functional group number of 2.01 or more consisting of a high molecular polyol and, if necessary, a low molecular polyol, α, α,
α'α'-Tetramethylxylylene diisocyanate [hereinafter also referred to as TMX old]. ] Blocked products of NGO urethane prepolymers made from organic diisocyanate compounds are mentioned.

In organic diisocyanates including TMX old, TMI
Examples of DI include 0-+m-+p and mixtures thereof. Preferred is m-TMIDI.

Organic diisocyanates other than TMIDI include aliphatic diisocyanates [hexamethylene diisocyanate (HD), lysine diisocyanate, etc.] and alicyclic diisocyanates [hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), inphorone diisocyanate (IPDI), cyclohexane diisocyanate (C
HD, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, etc.], aromatic diisocyanate [tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthylene diisocyanate, xylylene diisocyanate, etc., and two of these. Mixtures of the above may be mentioned. Among these, preferred are aliphatic diisocyanates, and particularly preferred is ①.

The amount of TMX in the organic diisocyanate is usually at least 50% by weight, preferably at least 60%.

As a polymer polyol, the molecular weight per hydroxyl group is usually 5.
00 to 3000 polymer polyols are mentioned.

Examples of the polymer polyols include polyether polyols, polyester polyols, polymer polyols, polycarbonate polyols, and mixtures of two or more thereof.

Examples of polyether polyols include polytetramethylene glycol (PTMG), which can be obtained by ring-opening polymerization of tetrahydrofuran. Polytetramethylene glycol is described in JP-A-58-11518. Furthermore, alkylene oxide adducts of low-molecular polyols can also be used.

As a low-molecular polyol, the molecular weight per hydroxyl group is usually 3.
0-500, preferably 30-400 diols such as ethylene glycol, propylene glycol, 1,4
-Butanediol and 1,8-hexanediol; molecular weight per hydroxyl group is usually 30 to 600, preferably 40
Examples of low molecular weight triols having a molecular weight of 50 θ include glycerin, trimethylolpropane, and mixtures of two or more thereof. As alkylene oxide,
Ethylene oxide, propylene oxide, 1.2-
．． Examples include 1,3- or 2,3-butylene oxide, tetrahydrofuran, styrene oxide, epichlorohydrin, and mixtures of two or more thereof.

Examples of the polyester polyol include polyester polyols obtained by polycondensing dicarboxylic acids, their esters or halides, and low-molecular polyols. Examples of dicarboxylic acids include aliphatic dicarboxylic acids (adipic acid, sepathic acid, maleic acid, dimer acid, etc.), aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, etc.), and their anhydrides. Among the dicarboxylic acids, preferred are aliphatic dicarboxylic acids, and particularly preferred is adipic acid. Examples of the low-molecular polyol include those described in the section on polyether polyols, and preferred are ethylene glycol and 1,4-butanediol. Also usable are polylactone polyols such as polycaprolactone diol (PCL) obtained by ring-opening polymerization of lactones (epsilon-caprolactone, etc.) in the presence of low-molecular polyols (ethylene glycol, etc.).

As the polymer polyol, those described in JP-A-55-118948 can be used.

Examples of polycarbonate polyols include those obtained from the above-mentioned low-molecular-weight polyols (di- or trihydric alcohols) and carbonic acid diesters (dimethyl carbonate, diethyl carbonate, etc.).

Among the polymeric polyols, preferred are polytetramethylene glycol and polyester polyol (especially polyethylene adipate diol and polycaprolactone polyol).

Examples of low-molecular polyols include those described in the section on polyether polyols, low-molar adducts of alkylene oxides (low-molecular-weight ones), and mixtures of two or more of these. Preferred among these are ethylene glycol and trimethylolpropane.

Examples of polyols with an average functional group number of 2.01 or more include (
b) Trifunctional polymer polyol with a molecular weight per hydroxyl group of 500 to 3000 and a molecular weight per hydroxyl group of 40 to 50
A polyol consisting of a low molecular weight triol of 0 and (b)
Examples thereof include trifunctional polymeric polyols having a molecular weight per hydroxyl group of 500 to 2,500 and polyols consisting of low molecular weight diols having a molecular weight per hydroxyl group of 30 to 400.

In NGO urethane prepolymers, the Neo10H equivalent ratio of organic diisocyanate and polyols is usually 1.
3 to 3.0, preferably 1.5 to 2.2.

In carrying out the prepolymer production reaction, known polymerization catalysts such as dibutyltin dilaurate, stannous octoate, stannous octoate, organometallic compounds, triethylenediamine, triethylamine, 1,8-diazabicyclo[ It is also possible to use tertiary amine compounds such as 5,4,0]undecene-7.

The reaction is usually carried out in the presence of a solvent or plasticizer. Solvents or plasticizers that are generally used for this purpose are all suitable; solvents include, for example, aromatic hydrocarbons (toluene, xylene, trimethylbenzene, etc.), esters (ethyl acetate, butyl acetate, etc.), ethers, etc. Examples of plasticizers include diethyl phthalate, dibutyl phthalate, dioctyl phthalate, and dilauryl. phthalate,
Ester-type plasticizers such as phthalate esters such as distearyl phthalate and diisononyl phthalate, adipate esters such as dioctyl adipate, separatate esters such as dioctyl sebacate, phosphate esters such as tricresyl phosphate, and these two. Mention may be made of mixtures of more than one species.

The reaction temperature is usually 40-140°C, preferably 60-12°C.
It is 0゛C. The reaction time is usually 3 to 0 hours, preferably 4 to 8 hours.

The molecular weight of the obtained urethane prepolymer (a) is usually 5.
00-1000G, preferably 700-8000G. If the molecular weight is less than 500, the resin will become hard and brittle, which will have an unfavorable effect on the physical properties of the fired plastisol, and if it exceeds 10,000, it will be difficult to obtain good adhesion. In addition, the N00% of this prepolymer is usually 1 to
20%, preferably 2-15%.

Blocking agents used to obtain the blocked urethane prepolymer (b) include oxime compounds such as acetoxime, ketoxime, etc.
caprolactam, etc.); active methylene compounds [malonate diesters (diethyl malonate, etc.), acetylacetone, acetoacetate (ethyl acetoacetate, etc.), etc.; phenols (phenol, m-cresol, etc.); alcohols (methanol, ethanol, n Hydroxyl group-containing ethers (methyl cellosolve, butyl cellosolve, etc.); Hydroxyl group-containing esters (ethyl lactate, amyl lactate, etc.); Mercaptans (butyl mercaptan, hexyl mercaptan, etc.); Acid amides (acetanilide, acrylamide, dimer acid, etc.) imidazoles (imidazole, 2-ethylimidazole, etc.); acid imides (succinimide, phthalimide, etc.), and mixtures of two or more of these.

Preferred among these are oxime compounds and lactams, and particularly preferred are MEK oxime and ε-caprolactam.

Among these, blocking agents suitable for relatively low-temperature baking are those whose dissociation temperature for regenerating isocyanate groups is generally within the range of 50 to +00°C, although this varies depending on the type of incyanate.

A blocking agent can be added and reacted at any stage of the above reaction to obtain a blocked urethane prepolymer (b). Possible methods of addition include adding at the end of a predetermined polymerization, adding at the beginning of the polymerization, or adding a portion at the beginning of the polymerization and adding the remainder at the end of the polymerization. Preferably, it is added at the end of polymerization.

When added at the end of polymerization, the amount added is usually based on the free insyanate groups of the NCO prepolymer! 1 equivalent or more and less than 2 equivalents, preferably 1.05 to I.

5 equivalents. Also, when adding a blocking agent midway through,
It is preferable to use the blocking agent in an amount approximately equivalent to the NGO equivalent of the raw diisocyanate minus the equivalent of the polyol.

The reaction temperature when adding a blocking agent is usually 50°C.
~150°C. It is also possible to accelerate the reaction by adding a known catalyst for urethane polymerization.

The active amine group-containing mono- or polyamide compound (C), which is the other essential component of the adhesion imparting agent (C) in the present invention, is known as an epoxy resin curing agent,
Examples include monoamide compounds and polyamide compounds (polyamide resins) obtained by reacting at least one selected from the group consisting of polymerized fatty acids and monobasic acids with polyamines. As the above-mentioned polymerized fatty acids, -basic acids and polyamines, those described in Japanese Patent Publication No. 53-41121 and Japanese Patent Publication No. 53-41122 can be used.

The amine value of the mono- or polyamide compound (C) is usually 90 or more, preferably 100-450, particularly preferably 150-400. Since those having an amine value of less than 90 generally have a high molecular weight, their compatibility with plastisol decreases. This compound was published in Japanese Patent Publication No. 55-11894.
It is described in Publication No. 8 and can be used.

Mono- or polyamide-based compounds (C) include partially modified versions thereof, such as those containing an imidacillin ring in the molecule, or mono- or polyamide-based compounds (C) with vinyl compounds having electron-withdrawing groups (acrylonitrile, epoxy acrylate, etc.) A modified compound having an active amino group modified with a compound such as
It also includes ketimine, which is a modified compound with a ketone compound (such as methyl ethyl ketone or methyl isobutyl ketone).

Furthermore, the mono- or polyamide-based compound (C) may contain free polyamine. Examples of this polyamine include aliphatic polyamine [alkylene (C2-C,)
polyalkylene polyamines (diethylenetriamine, dipropylenetriamine, triethylenetetramine, etc.), aromatic polyamines (phenylenediamine, tolylenediamine, xylylenediamine, etc.), alicyclic polyamines (cyclohexylene, etc.) Examples include diamines, inphorone diamines, diaminodicyclohexylmethane, dimethyldiaminodicyclohexylmethane, etc.), heterocyclic polyamines [piperazine, aminoalkyl-substituted piperazines (aminoethylpiperazine, etc.), etc.], and mixtures of two or more of these. For polyamines, see JP-A-54-122395 and JP-A-54-101899.
Those described as polyamines in the publication can be used. Preferred among polyamines are polyalkylene polyamines.

The plastisol composition of the present invention contains, in addition to the adhesion imparting agent (C), a vinyl chloride polymer or copolymer (A) and its plasticizer (B) as main components. As the vinyl chloride polymer or copolymer (A), those commonly used can be used. Examples of vinyl chloride copolymers include copolymers of vinyl chloride and other vinyl monomers that can be copolymerized with vinyl chloride, such as vinyl acetate, maleic anhydride or maleic esters, and vinyl ethers. The degree of polymerization of vinyl chloride polymer or copolymer is usually 1000~! It is 700. Kanevinyl PS is a commercially available vinyl chloride polymer or copolymer.
L-10, Kanevinyl PSH-10, Kanevinyl PCI
I-12 (manufactured by Kanebuchi Chemical Industries), Zeon 121 and Zeon 135J (manufactured by Nippon Zeon), Denkavinyl P
A-100, and Denkabinir ME-180 (hereinafter referred to as Denka Kagaku Kogyo type). These can also be used in combination of two or more.

As the plasticizer (B), all those generally used for this purpose are effective, such as phthalic acid esters such as diethyl phthalate, dibutyl phthalate, dioctyl phthalate, dilauryl phthalate, distearyl phthalate, diisononyl phthalate, dioctyl adipate, etc. Examples include ester type plasticizers such as adipate esters such as adipic acid esters, sepatic acid esters such as dioctyl sebacate, phosphoric acid esters such as tricresyl phosphate, and mixtures of two or more of these.

Preferred among these are phthalate esters, especially dioctyl phthalate.

In addition to the above-mentioned components (A), (B) and (C), various other additives such as fillers and stabilizers can be added to the composition of the present invention. Examples of fillers include inorganic fillers (calcium carbonate, talc, diatomaceous earth, kaolin, etc.) and organic fillers (cellulose powder, powdered rubber, recycled rubber, etc.). Stabilizers include metal soaps (calcium stearate, aluminum stearate, etc.), inorganic acid salts (dibasic phosphites, dibasic sulfates, etc.), and organic metal compounds (dibutyltin dilaurate, dibutyltin malate, etc.). Can be mentioned. Further, coloring agents such as pigments can also be optionally added.

In the plastisol composition of the present invention, the content of each component is not particularly limited, but an example of the formulation is as follows. (% is weight%) Usually preferably vinyl chloride weight 10-50% (20-40%)
Combined or copolymer (A) Plasticizer (B) 10-50% (20-4
0%) Adhesive agent (C) 0. ．． 5-20%
(1-10%) Additives 0-70% (
0-80%) When using fillers as additives,
Usually 10 to 70% (preferably 20 to 60%), and when a stabilizer is used, usually θ to 3% (preferably 0.
1-2%).

The plastisol composition of the present invention can be produced using a commonly used dispersion kneader.

The plastisol composition of the present invention can be applied to various metal base surfaces and various undercoated surfaces applied to metal (especially steel) surfaces, but it can be particularly advantageously applied to cationic electrodeposition painted surfaces and acrylic resin painted surfaces. For cationic electrodeposition coating, for example, polyamine resin (such as epoxy resin having an amino group in the molecule) is used as a film-forming component, and this is neutralized with a lower organic acid to form an aqueous solution or water dispersion. One example is a coating method in which a body fluid is used as a paint (present as a cation), and the object to be coated (metal) is used as a cathode, and the paint is deposited on the surface of the object by direct current flow.

Acrylic resin paints used for acrylic resin coating include thermoplastic type and thermosetting type. The thermoplastic type is mainly used for drying at room temperature, using acrylic polymer in combination with cellulose derivatives, trocellulose, cellulose acetate butyrate, plasticizers, etc. The thermosetting type has a functional group in the acrylic (co)polymer and forms a three-dimensional network structure when heated alone or by reaction with a crosslinking agent. Painting methods include single coating, spray coating, electrostatic coating, flow coating, dipping coating, powder coating,
Examples include roller coats.

The amount of the plastisol composition of the present invention applied to the above-mentioned painted surface is usually 500 to 3000 g/m2, and the coating thickness is usually 0.3 to 2 mm.

Painting methods include brush painting, roller coating, and airless spray painting.

Further, heat treatment is performed after coating, and the temperature in that case is usually 120 to 140°C and the time is usually 20 to 40 minutes.

[Examples] The present invention will be further explained below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In the examples, parts or percentages are based on weight.

Example 1 (+) Production of blocked urethane prepolymer Stirrer,
183 parts of polycaprolactone diol (PCL) (hydroxyl value 140, molecular weight 800), 27 parts of trimethylolpropane (molecular weight 134), α, α, α
', α'-Tetramethylxylylenediamine (TMXD
I) 248 parts (molecular weight 244) and 360 parts of xylene were charged and reacted for 3 hours at 90 to 95°C under a nitrogen stream, and then dibutyltin dilaurate 0.03
The mixture was further reacted at the same temperature for 2 hours to obtain a urethane prepolymer having an active incyanate content of 5.3%. Furthermore, 57 parts of ε-caprolactone (molecular weight 113) was added to this mixture, and the temperature was kept at 90 to 95°C under a nitrogen stream.
for 3 hours, then MEK oxime (molecular weight 87
) was gradually added and stirred at 70'C for 1 hour.
The absorption of incyanate group (2
250 cm-') was confirmed to have completely disappeared, and a blocked urethane prepolymer (b) which was a low viscosity liquid at room temperature was obtained.

(2) Production of plastisol composition 70 parts of Kanevinyl PSL-10 (straight resin manufactured by Kanebuchi Chemical Industries), 30 parts of Kanevinyl PCI+-12 (copolymer resin manufactured by Kanebuchi Chemical Industries), dioctyl phthalate (
DOP) 110 parts, NCC-110 (Nippon Funka Kogyo, calcium carbonate) 150 parts, dibasic lead phosphite 3 parts, the above blocked urethane prepolymer (b) 8.7
Part and polyamide-based compound [Polymide L-2590 (manufactured by Sanyo Chemical Industries, Ltd. 1, amine value 285, active hydrogen equivalent 130
13.3 parts were uniformly kneaded to prepare a plastisol composition.

(3) Characteristics of the plastisol composition The initial viscosity of the plastisol is 380 (PS/25°C)
The viscosity after storage for 14 days at 40°C is 480 (
PS/25°C). When the plastisol composition was applied to a steel plate coated with cationic electrodeposition to a coating thickness of 0.5 mm and heat treated at 120°C for 20 minutes, it showed excellent elasticity and excellent adhesion. A coating film was obtained. Further, after immersing this product in 40'C warm water for 10 days, there was almost no change in adhesion.

Furthermore, the JIS standard is applied using a cationic electrodeposition coated plate as an adherend.
Measure the tensile shear strength according to the method described in K 8830 (automobile, sealant test method) (sol thickness l, Omm, heat treatment 120'CX20
The result was 20.1 kg/cm2.

Examples 2 to 4 and Comparative Examples 1 to 2 Tables 1 and 2 were prepared using the same method as described in Example 1.
Blocked urethane prepolymers and plastisol compositions were produced according to the description in Table 3, and their properties are listed in Table 3.

However, the production conditions for the blocked urethane prepolymer were 75 to 80°C when the isocyanate was TDI.

[Effects of the invention] The vinyl chloride plastisol composition of the present invention maintains the adhesion to conventional electrodeposited coatings and the storage stability of the sol, while reducing the baking temperature by about 10 to 20°C compared to conventional ones. Is possible. Therefore, the thermal energy required during application of these rust preventive agents is greatly reduced, which is a great industrial advantage.

The plastisol composition of the present invention has the effect of strongly adhering to many substrates, such as cationic electrodeposition coated surfaces as well as acrylic coated surfaces, by heat treatment at a relatively low temperature and for a short time (for example, 120°C, 20 minutes). play. In addition to the above effects, it has excellent storage stability, is quite stable even under severe conditions such as 40° C. for 14 days, and has the effect of causing little increase in viscosity.

The plastisol composition of the present invention can be applied to various industrial applications as adhesives, sealants, paints, etc., but it is particularly useful in the automobile industry, especially as a body sealer and undercoat paint for automobile bodies where cationic electrodeposition is applied as an undercoat. There is.

Claims (1)

[Scope of Claims] 1. In a plastisol composition comprising a vinyl chloride polymer or copolymer (A), a plasticizer (B), and an adhesion-imparting agent (C) as essential components, the adhesion-imparting agent (C) but/
(1) Blocked urethane prepolymer (b) with a blocking agent of urethane prepolymer (a) having isocyanate groups made from an organic diisocyanate containing α, α, α′, α′-tetramethylxylylene diisocyanate and polyols ) and (2) an active amino group-containing mono- or polyamide compound (c). 2. The composition according to claim 1, wherein the blocking agent is an oxime compound and/or a lactam.