JPH01289854A - Plastisol composition - Google Patents

Abstract

PURPOSE:To provide a plastisol composition excellent in adhesion, water resistance, storage stability, etc., by using a monoisopropylphenol-blocked aromatic diisocyanate polymer as a tackifier. CONSTITUTION:This plastisol composition is produced by mixing a vinyl chloride polymer (e.g., vinyl chloride/vinyl acetate copolymer) with a plasticizer (e.g., dioctyl phthalate), a tackifier comprising a monoisopropylphenol-blocked aromatic diisocyanate polymer (e.g., tolylene diisocyanate polymer) and a thermal cleavage promoter (e.g., dibutyltin laurate) as essential components. Because the obtained plastisol composition contains the tackifier, it can be easily and firmly adhered to a steel sheet surface electrocoated with a difficultly bondable cationic coating agent and can be desirably used as a coating agent or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to plastisol compositions. More specifically, the present invention relates to plastisol compositions that are optimal for use as adhesives, sealants, coatings, etc. in various industries including the automobile industry.

[Conventional technology]

In plastisol compositions, it is known to add an organic polyisocyanate compound as a method of improving the adhesion of the plastisol.

For example, JP-A-57-105441 describes adding tolylene diisocyanate or an incyanate polymer obtained by trimerizing diphenylmethane diisocyanate to plastisol. In addition, JP-A-57
No. 131669 proposes adding a lactam block polyisocyanate, and JP-A No. 62-41278 proposes adding a long-chain alkyl (4 or more carbon atoms) phenol block of an aromatic diisocyanate polymer. There is.

In the plastisol composition of JP-A-57-105441, the terminal is a free isocyanate group (Neo group).
Therefore, it has the drawbacks of high reactivity, stability problems, and short shelf life. In addition, when using a block material, the blocking agent is decomposed, so if polyamide containing active amino groups is used as a thermal decomposition accelerator, the resulting coating film will discolor due to heat and is not water resistant. In addition, when the protective agent is a long-chain alkylphenol, discoloration is improved, but satisfactory adhesion is still not obtained on metal painted surfaces (cationic electrodeposition coated steel plate surfaces). Not yet. This is particularly noticeable on thick cationic electrodeposition coated surfaces.

[Problem to be solved by the invention]

The present inventors have solved these drawbacks and created a plastisol composition that firmly adheres to cationic electrodeposited surfaces, has excellent water resistance, forms a coating film that does not discolor due to heat, and has excellent storage stability. As a result of investigation to obtain aromatic diisocyanate)
The present invention was achieved by using a monoisopropylphenol block of Compound 31 as an adhesion imparting agent.

[Means to solve the problem]

The present invention provides a plastisol composition comprising a vinyl chloride polymer, a plasticizer, an adhesion promoter, and a thermal cleavage accelerator, which contains a monoisopropylphenol block of an aromatic diisocyanate polymer as the adhesion promoter. In the plastisol composition.

To explain the present invention in detail, the vinyl chloride A/based polymer used in the plastisol composition of the present invention is a homopolymer of vinyl chloride or a copolymer of a monomer copolymerizable with vinyl chloride. As copolymerizable monomers,
Vinyl esters such as vinyl acetate, vinyl propionate, vinyl stearate; methyl (meth)acrylate, ethyl (meth)acrylate, buty/L/[methacrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl ( (meth)acrylic acid esters such as meth)acrylate; diethyl maleate,
Examples include maleic acid esters such as dibutyl maleate; fumaric acid esters such as diethyl/%/7 maleate and dibutyl fumarate; and vinyl ethers such as vinyl methyl ether and vinyl butyl ether. It is about 2000. Examples of commercially available vinyl chloride homopolymers or copolymers include Zeon 121 and Zeon 3.
7J (manufactured by Nippon Zeon), Kanevinyl PSL -
1O, Kanevinyl PSH-10, Kanevinyl #PSM-
80, Kanevinyl Pam-12 (manufactured by Kanekabuchi Kagaku Kogyo Co., Ltd.), and Denkavinyl FA-1000% 7'-Kanevinyl MIC-180 (11E made by Kikagaku Kogyo Co., Ltd.). These can also be used in combination of two or more types.

Plasticizers commonly used for this purpose are:
All are useful, such as di-n-octyl phthalate (D
OP), di-2-ethylhexyl 7-talate, diisononyl phthalate (D-NP), dibutyl fumarate (DHP), and other 7-talic acid-based plasticizers; di-2-ethylhexyl adipate (DOA), azelaic acid di-2 - Fatty ester plasticizers such as ethylhexyl and sebacin-2-ethylhexyl; phosphorus ester plasticizers such as tributyl phosphate and tri-2-ethylhexyl phosphate, etc. , hardness after curing, heat resistance, viscosity, compatibility, and other required properties, and can be used alone or in combination of two or more. The amount of plasticizer used is 30 to 300 parts by weight per 100 parts by weight of the vinyl chloride polymer.
It is best to use within the range of parts by weight.

The adhesion imparting agent used in the present invention is a monoisopropylphenol block of aromatic diisocyanate polymer for imparting adhesion to plastisol. these,
Examples of the aromatic diisocyanate (monomer) constituting the aromatic diisocyanate polymer include tolylene diisocyanate, diphenylmethane diisocyanate, and xylene diisocyanate, which may be used alone or
They may be used by mixing them in any proportion, and a part thereof may be replaced with an aliphatic diisocyanate such as hexamethylene diisocyanate or an alicyclic diisocyanate such as isophorone diisocyanate.

The aromatic diisocyanate polymer is preferably synthesized in a plasticizer used in the target plastisol composition, and in some cases, an inert solvent such as butyl acetate may also be used. Catalysts for this polymerization include Mannich base, alkali metal salts of fatty acids, etc., which are obtained by polymerization (cyanurate formation) by a known method, and then blocked with monoisopropylphenol to form an aromatic diisocyanate polymer. An isopropylphenol block is produced.

The blocking agent used in the present invention, monoisopropylphenol, has ortho, meta, and para isomers, and it may be used alone or as a mixture, but it is preferably blocked with ortho or para isomers. good.

The amount of the monoisopropylphenol block added to the aromatic diisocyanate polymer of the present invention is in the range of 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight per 100 parts by weight of the vinyl chloride polymer. It is good that it is within the range of

Thermal cleavage accelerator is used to cleave blocks of aromatic diisocyanate polymers, and includes fatty acids having 8 to 2 carbon atoms such as zinc octylate, potassium laurate, barium oleate, and calcium stearate. Metal salts include tin compounds such as dibutyltin laurate, dioctyltin maleate, dibutyldibutoxytin, and bis(2-ethylhexyl)tin oxide, and one or more of these may be used as appropriate, with tin compounds being particularly preferred. The amount used is not particularly limited, but varies depending on the type. - It is necessary to choose an appropriate amount because it tends to impair storage stability for boat fishing. The amount of the tin compound used in the present invention is preferably 0.05 to 5 parts by weight or 0.2 to 2 parts by weight per 100 parts by weight of the vinyl chloride polymer.

In addition to the above-mentioned components, the plastisol composition of the present invention may contain other additives such as fillers, thickeners, stabilizers, adsorbents, etc., although these additives are not limited. Examples of fillers include kaolin, diatomaceous earth, and talc, and examples of thickeners include bentonite, anhydrous silica, and metallic soap. Metal soaps are also used as stabilizers, such as zinc stearate, calcium stearate, barium oleate, etc., and can be used alone or as a combined stabilizer. Further, as an adsorbent, when the plastisol contains water, powders such as magnesium oxide, calcium oxide, silicon oxide, etc. are added and used.

The plastisol composition of the present invention is prepared by uniformly kneading a vinyl chloride polymer, a stabilizer, an adhesion improver, a thermal cleavage accelerator, and other additives as necessary using a dispersion mixer. Manufactured by foaming.

The plastisol composition of the present invention has advantages such as strong adhesion to gold film coated surfaces (especially cationic electrodeposition coated surfaces) and good storage stability. It is used for purposes such as lining and sealing pinholes.

The amount of coating varies depending on the application and is not particularly limited, but it is used, for example, as an undercoat for a topcoat. In this case, the coating thickness is preferably in the range of 0.5 m to 5 m. As for the application method, a conventional method is appropriately selected depending on the application, and common methods include pouring, dipping, spraying, and buffing.

Conventionally, the plastisol composition applied to the object to be coated is usually heated to a temperature of 140°C to 180'Cf to thermally dissociate the block and harden it, but the plastisol composition of the present invention is heated to a temperature of 120°C to 180°C. Strong adhesion is exhibited by heat treatment at a temperature of ~140°C for 15 to 30 minutes.

[Effect]

Since the plastisol composition of the present invention contains a block of an aromatic diisocyanate polymer blocked with monoisopropylphenol as an adhesion agent, it can withstand temperatures of 120° C.
It is easily and firmly bonded by heat treatment for 15 to 30 minutes in a temperature range of 140"C. That is, the monoisopropylphenol used in the present invention has a lower molecular weight among alkylphenols, and it is difficult to bond. Since the content of isocyanate groups in the added amount of the property-imparting agent increases and the blocking agent is easily decomposed because it is an isoform, the plastisol of the present invention can be imparted with strong adhesive properties by the above-mentioned heat treatment. The composition has advantages such as easy handling, good storage stability, and no extreme increase in viscosity even when left for a long time.

Furthermore, the plastisol composition of the present invention has the advantage that it does not become colored during processing or by heat treatment after application, and there is no need to worry about discoloration even when a thin top coat is applied. It can be applied as a sealant, coating agent or adhesive for the protection of substrates, especially in the automobile industry, for rust prevention of bodies coated with cationic electrodeposition, a! Excellent as a paint for sealing holes and pinholes.

〔Example〕

The effects of the present invention will be explained below with reference to Examples and Comparative Examples. In the Examples and Comparative Examples, parts and % indicate parts by weight and i% by weight unless otherwise specified.

Reference example Monoisopropylene pill of tolylene diisocyanate polymer 7
100 parts of tolylene diisocyanate, 400 parts of dioctyl 7-talate, and 0.6 parts of potassium caprylate as a polymerization (cyanurate) catalyst were charged into a flask equipped with a stirrer, a thermometer, and a nitrogen inlet tube. 25-60° under nitrogen flow
C until the isocyanate content reached 3.2% to form a polymer (cyanurate compound), and then 78.3 parts of 0-isopropylphenol and dioctyl phthalate).
313.2 parts and 0.3 parts of dibutyltinlaure) were added, and the reaction was carried out in a temperature range of 50 to 80°C under a nitrogen stream until the absorption of isocyanate groups (NOOg) in the infrared absorption spectrum (2260C+l-') disappeared. A dioctyl phthalate solution containing 20% 0-isopropylphenol block of tolylene diisocyanate polymer was produced. This was considered as the adhesion imparting percentage. Table 1 shows products produced in a similar manner using isomers of monoisopropylphenol, metaisopropylphenol and paraisopropylphenol as blocking agents.

Table 1 Comparative Reference Example A dioctyl phthalate solution of a block of an aromatic diisocyanate polymer was produced according to the production method of the reference example using the following alkylphenol as a blocking agent,
The adhesion imparting agent D1 was 1F and shown in Table 2.

-hehe Table 2 Example 1 Production of plastisol composition Vinyl chloride polymer Zeon 37J (manufactured by Nippon Zeon Co., Ltd.) 10
0 parts, 130 parts of Diocti/I/7 tallate, 200 parts of calcium carbonate, 5 parts of stabilizer (Pb3O4), part A2B of the adhesion promoter obtained in the reference example, and 2 parts of thermal cleavage accelerator (diptyltin laurate). using a kneader at room temperature.
Plastisol composition 1 was produced by kneading and defoaming for 0 minutes.

Example 2 The vinyl chloride/I/polymer in Example 1 was replaced with Zeon 3'
7,780 copies, and Zeon 121 (manufactured by Nippon Zeon Co., Ltd.) 2
Plastisol composition 2 was prepared in the same manner as in Example 1, except that 100 parts of the polyvinyl chloride polymer mixture of Example 2 was prepared using the method of Example 1 above, and In place of the adhesion-imparting agent A of Example 1, adhesion-imparting agents B to G of Table 1 above were used, respectively.
Plastisol compositions 3 and 4 were manufactured using the same amount of .

Comparative Examples 1 to 3 Plastisol compositions of Comparative Examples 1 to 3 were prepared by using the same amount of the adhesion imparting agent D-IF of the comparative reference example in Table 2 in place of the adhesion imparting agent A in Example 2. Manufactured.

Evaluations of Examples 1 to 4 and Comparative Examples 1 to 3 of the plastisol compositions described above were conducted using the following tests.

(1) Storage stability test of plastisol composition The viscosity of the produced plastisol composition at a temperature of 20°C was measured using a Pruckfield BH type viscometer, and this was taken as the initial viscosity. The plastisol composition was placed in a container and left in a constant temperature bath at 40°C±1°C for 7 days, after which the viscosity was measured in the same manner to determine its viscosity increase rate.

(2) Tensile shear strength test using cationic electrodeposition coated plate as adherend J-K5K-6830
(Automotive sealant test method), the shear strength was measured (however, the thickness of the plastisol coating was 0.
．． 2 m, heat treatment was performed at 120° C. for 30 minutes, and the pulling rate was 25 mm/min). The condition of the sheared surface was visually observed.

(Discoloration test of rapid coating film A cationic electrodeposition coated plate was used as the adherend, and the plastisol composition was applied to a coating film thickness of 5 mm.
After heat treatment at °C for 10 minutes, a top coat (Super White 326 manufactured by Kansai Paint Co., Ltd.) was applied to a film thickness of 5μ, and heat treatment was performed at 140 °C for 20 minutes. Tested for color change after 200 hours of exposure with a meter.

The test results are shown in Table 3.

m-'.1-'',,'-,L1! However, the adhesion imparting agent was used as a 20% Dop solution.

(1) 018 No color Δ; Partial enveloping coloring; Coloring [Effects of the invention] The plastisol composition according to the present invention exhibits excellent adhesiveness (shear strength).

Patent applicant: Kyoeisha Yushi Kagaku Kogyo Co., Ltd. Procedural amendment 1, Indication of case: 1988 Patent Application No. 119966 3, Person making the amendment 4, Agent 6, Contents of the amendment (1) Specification, page 2, number 8 After the line "JP-A-62-41278", insert "and JP-A-62-190267".

that's all

Claims (1)

[Claims] 1. A plastisol composition comprising a vinyl chloride polymer, a plasticizer, an adhesion promoter, and a thermal cleavage accelerator,
A plastisol composition comprising a monoisopropylphenol block of an aromatic diisocyanate polymer as an adhesion imparting agent.