JPH0782549A - Vinyl chloride plastisol type sealant - Google Patents

Abstract

PURPOSE:To provide a vinyl chloride plastisol type sealant containing a plasticizer difficultly extractible with the surfacer, having excellent spreadability, and scarcely suffering from stringing or sagging during application. CONSTITUTION:This sealant is one in which a polyester plasticizer of a molecular weight of 1500 or above constitutes 25-60wt.% of the plasticizer component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride plastisol-based sealant used as a watertight / airtight seal for a body panel joint of an automobile.

[0002]

2. Description of the Related Art A joint portion of an automobile body panel is coated with a vinyl chloride plastisol-based sealing material to fill a gap, and then an intermediate coating and a top coating are applied. In addition, preliminary baking may be performed before the intermediate coating and the top coating, but in view of work efficiency, the preliminary baking may be omitted and the intermediate coating and the top coating may be performed in a dry state. Phthalates such as dioctyl phthalate are usually used as a plasticizer in a sealant, but in the above process, a phenomenon occurs in which the plasticizer in the sealant is extracted into the intermediate coating material. For this reason, there is a problem that the smoothness and gloss are hindered by the cissing of the top coating material. As a method for solving such a problem, there is known JP-A-4-146986 in which a polyester-based plasticizer is used as a plasticizer used in a sealing agent to make it difficult for the plasticizer to be extracted into an intermediate coating composition.

[0003]

However, since the polyester type plasticizer is more expensive than the phthalate ester type plasticizer, it cannot be used alone in a limited part. Further, there is a drawback that the phenomenon of stringing and sagging easily occurs in the process of applying the sealing material, which makes it difficult to work. Also, when a general-purpose plasticizer is mixed with a polyester plasticizer, although the topcoat paint is slightly repelled,
The effect is lower than when using a polyester plasticizer alone. The present inventors have earnestly studied vinyl chloride plastisol-based sealing materials. As a result, by using a polyester plasticizer having a molecular weight of 1500 or more in 25 to 60% by weight of the plasticizer component in the sealing material, the plasticizer is difficult to be extracted into the intermediate coating material, and the sealing material is applied. It was found that the phenomenon of stringing and sagging became less likely to occur during the process, and the present invention was completed based on this finding. As is apparent from the above description, an object of the present invention is to provide a vinyl chloride plastisol-based sealing material which has excellent coatability and is resistant to stringing and sagging.

[0004]

Means for Solving the Problems The present invention includes the following (1):
It has the configuration of (2). (1) 25 to 60% by weight of the plasticizer component has a molecular weight of 1500
A vinyl chloride plastisol-based sealing material comprising the above polyester-based plasticizer. (2) The diol component of the polyester plasticizer is 2-n-
The vinyl chloride plastisol-based sealing material according to (1) above, which is obtained by blending a polyester-based plasticizer which is butyl-2-ethyl-1,3-propanediol.

The polyester plasticizer used in the present invention is a polyester plasticizer composed of an aliphatic dibasic acid, a diol, and a monohydric alcohol or a monobasic acid, preferably 2-n in the diol component. -Butyl-2
-Molecular weight 15 including ethyl-1,3-propanediol
It is a polyester-based plasticizer of 00 or more. Examples of the aliphatic dibasic acid include adipic acid, azelaic acid and sebacic acid, and examples of the diol include 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol and propylene glycol, and monohydric alcohols. Examples thereof include octanol and isononyl alcohol, and examples of the monobasic acid include coconut oil fatty acid. Polyester-based plasticizers that are commonly used as sealing materials have a molecular weight of 1000 or less and a viscosity of 10 at 25 ° C.
Although it is not more than 00 mPa · s, the polyester plasticizer used in the present invention has a molecular weight of 1500 or more and a viscosity of 2000 m.
Pa · s or more, preferably a molecular weight of 2000 to 3
The viscosity is 5,000 to 10,000 mPa · s at 000. The polyester-based plasticizer of the present invention is specified as 25 to 60% by weight of the plasticizer component of the sealant. If the polyester plasticizer of the present invention is 25% by weight or less of the plasticizer component, the effect of compounding cannot be expected, and if it is 60% by weight or more, the viscosity as a sealing material becomes high and the workability deteriorates.

Dioctyl phthalate (D) is used as a plasticizer other than the above polyester plasticizers in the present invention.
OP), diisononyl phthalate (DINP), butylbenzyl phthalate (BBP) diisodecyl phthalate (DIDP) and other phthalic acid plasticizers, tricresyl phosphate (TCP), trioctyl phosphate (TOP) and other phosphate plasticizers, dioctyl Fatty acid plasticizers such as adipate (DOA) and dioctyl sebacate (DOS),
Examples thereof include trimellitic acid plasticizers such as trioctyl trimellitate (TOTM).

In the vinyl chloride plastisol-based sealing material of the present invention, a vinyl chloride-based resin, a filler, an adhesion-imparting agent, and other commonly used additives can be used in addition to the plasticizer.

The vinyl chloride resin used in the present invention may be any one for ordinary plastisols, and may be a homopolymer of vinyl chloride or a copolymer of this with another copolymerizable monomer. Also, a mixture of several kinds of polymers or a polymer blend may be used.

Examples of the filler used in the present invention include surface-treated calcium carbonate, clay, talc, silica and the like, and at least one of them is used. As the adhesion-imparting agent, for example, dicyandiamide, amine, polyamidoamine, etc. are used.

[0010]

The plasticizer is not easily extracted even when the intermediate coating material having a high polar solvent content is applied onto the sealing material to which the present invention is applied. Therefore, even if the top coat paint is further applied in a state where the intermediate coat paint is not dried, the top coat paint is not repelled. In addition, the stringing phenomenon and sagging that occur when a polyester plasticizer is used are less likely to occur.

[0011]

EXAMPLES Examples of the present invention will be described in detail below. Table 1 shows the composition of the sealing material and the result of the performance test. Examples 1 to 4 in Table 1 are examples of sealing materials to which the present invention is applied, and Comparative Examples 1 to 5 are examples of sealing materials to which the present invention is not applied.

First, the sealing material of each example is adjusted. Vinyl chloride resin, plasticizer, heavy calcium carbonate, white luster CC
R (trademark), tribasic lead sulfate, mineral spirit, and amine-based adhesion promoter are each weighed in the composition (parts by weight) shown in Table 1. It is kneaded with a vacuum crusher and defoamed to obtain a sealing material.

Next, a performance test of the sealing material of each example is conducted. The static viscosity of the sealing material is No. 7 of B type viscometer (Vismetron VG-HW type manufactured by Shibaura System Co., Ltd.).
Rotor, measured at 20 rpm.

The coatability was tested without calcination of the sealing material. First, a sealant is applied to a JIS G3141 (SPCC-SB) steel plate, and as it is (in a wet state), an intermediate coating of thinner A-20 parts for paint (Kansai Paint Co. Film thickness 30
μm).

While still in a wet state, 100 parts of vehicle phthalates manufactured by Kansai Paint are used, and paint thinner A-2 is used.
Apply 0 part of top coat (coating thickness 30 μm). It 1
Bake at 40 ° C for 30 minutes. Examine the paint appearance after this baking is completed.

In the stringing test, a glass rod is put in the sealing material and slowly lifted in the vertical direction. If the sealing material cannot be cut immediately, the stringing is poor.

For the sagging test, a flow test was conducted using an electrodeposition coated plate in accordance with JIS K6830 (testing method for sealing materials for automobiles) test method (2). That is,
The sealing agent was applied on the iron plate, the iron plate was kept vertical, and the flow of the sealing agent after 10 minutes was measured. (However, sol thickness is 3 mm)

Various polyester plasticizers were synthesized as follows. Product using 2-n-butyl-2-ethyl-1,3-propanediol (DMH) adipic acid 205.5 g, D
MH 241.5g, and 2-ethylhexanol
83.2 g was charged into a flask having an internal volume of 1 L equipped with a thermometer, a nitrogen inlet tube, a stirrer, a water separator, and a reflux condenser, and heated while stirring in a nitrogen stream, and the temperature of the reaction solution was 140 ° C. At that point, 0.1 g of tetraisopropyl titanate was added as a catalyst, and the acid value of the reaction solution became about 20 (mgKOH / g) while continuously removing the produced water by a water separator. The temperature was controlled to 200 ° C. and the reaction was carried out for 2.5 hours. Then, this reaction system was subjected to a transesterification reaction at 220 ° C. for 2.5 hours under a reduced pressure of 2 mmHg to obtain a polyester plasticizer having an average molecular weight of 2100.

The average molecular weight was determined by hydrolyzing the produced polyester plasticizer, determining the glycol and alcohol compositions by gas chromatography, and determining the ester value (J
(By saponification value measurement of ISK6751) was measured and calculated from the measured values of both. The viscosity of the polyester plasticizer is a B-type viscometer (Vismetron VG-A4 type).
It was measured by Shibaura System Co., Ltd.

DMH / HD equimolar combination product adipic acid 275.4 g, DMH 163.7 g, 1,6
120.7 g of hexanediol (abbreviated as HD) and 104.0 g of 2-ethylhexanol were reacted under the same reaction conditions as above. A polyester plasticizer having an average molecular weight of 2300 was obtained.

DMH / HD equimolar combination product adipic acid 250.3 g, DMH 111.0 g, 1,6
Hexanediol (abbreviated as HD) 81.9 g and 2-ethylhexanol 180.6 g were reacted under the same reaction conditions as above. A polyester plasticizer having an average molecular weight of 980 was obtained.

1,3BG / HD used product Adipic acid 288.4 g, 1,3 butanediol (1,
83.3 g of HD (abbreviated as 3BG), 109.1 g of HD, and 148.0 g of 2-ethylhexanol were reacted under the same reaction conditions as above. A polyester plasticizer having an average molecular weight of 1020 was obtained.

Comparative Example 1 is an example in which a general polyester plasticizer alone is used as a plasticizer, and although the coating property is good, the stringing property and the sagging property are poor.

Comparative Example 2 is a case where the polyester plasticizer used in the present invention is used in an amount of 20% by weight or less of the plasticizer component, but the coatability is poor.

On the contrary, in Comparative Example 3, when the polyester-based plasticizer is used in an amount of 60% by weight or more of the plasticizer component, the coating property and the corrosiveness are good, but the sol viscosity becomes high, resulting in poor workability. .

In Comparative Example 4, when the molecular weight of the polyester plasticizer used in the present invention is 1500 or less, the coating property becomes poor.

In Comparative Example 5, the stringing property and the sagging property are deteriorated when the film is not of the high molecular weight type.

Examples 1 to 4 were excellent in coating property, stringing property and dripping property.

[0029]

EFFECTS OF THE INVENTION The sealing material to which the present invention is applied is easy to work because the phenomenon of stringing and sagging hardly occurs in the process of applying the sealing material. Further, since the plasticizer is difficult to be extracted into the intermediate coating material, it has excellent coatability.

[0030]

[Table 1]

Claims (2)

[Claims] 1. A plasticizer component having a molecular weight of 1 is 25 to 60% by weight.
A vinyl chloride plastisol-based sealing material, characterized by containing 500 or more polyester-based plasticizers. 2. The diol component of the polyester plasticizer is 2
The vinyl chloride plastisol-based sealing material according to claim 1, wherein a polyester-based plasticizer which is -n-butyl-2-ethyl-1,3-propanediol is blended.