JPH10237249A - Vinyl chloride plastisol composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vinyl chloride plastisol composition which can form a coating film capable of revealing good chipping resistance and sufficient soundproof performance even with a single-layer structure. SOLUTION: This composition comprises mainly a vinyl chloride polymer resin, a plasticizer and a filler, and it contains a liquid asphalt and a foaming agent. The coating film obtained from this composition is increased in bulk by the foaming agent and increased in flexibility by the liquid asphalt. Therefore, the soundproof performance can be sufficiently improved. Since the coating film is very thick because of the increase in bulk by the addition of a foaming agent, it can well prevent the coated surface from being damaged by, e.g. a small stone piercing the coating film so that it can reveal good chipping resistance.

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 composition, and more particularly, to a steel sheet or the like of an automobile, which is mainly applied to a wheel house or a floor of a floor of an automobile to provide soundproofing and chipping resistance. It relates to a vinyl chloride plastisol composition to be applied.

[0002]

2. Description of the Related Art A so-called chipping phenomenon occurs in a wheel house portion or a floor back portion of an automobile, in which a coating film is peeled off by collision of pebbles or gravel which causes tires to jump while the automobile is running. Conventionally, in order to prevent this chipping phenomenon, a vinyl chloride resin plastisol paint is applied to the surface of a steel sheet for an automobile which has been subjected to a chemical conversion treatment and an electrodeposition coating process, and dried to form a coating film for protecting a vehicle body. That is being done.

[0003] Conventional plastisol paints of vinyl chloride resin are usually used for coating formation with an emphasis on chipping resistance, and the coating formed after heating and drying is tough and hard. . Such hard and tough coatings are effective against chipping phenomena, but are not very effective against the absorption of sound generated when pebbles or gravel collides. For this reason, there is a demand for a plastisol paint based on a vinyl chloride resin, which can form a protective coating film that can exhibit both chipping resistance and soundproofing performance.

JP-A-8-182961 discloses a first layer composed of a coating film having excellent vibration damping properties and a second layer composed of a coating film having excellent chipping resistance formed on the first layer. And a multi-layer coating film which can exhibit both chipping resistance and soundproofing performance satisfactorily. Japanese Patent Application Laid-Open No. Hei 2-202560 discloses that a resin is formed by mixing a plasticizer such as a vinyl chloride polymer resin, a phthalate ester, and a filler such as calcium carbonate as a main component, and mixing a foaming agent with the filler. A vinyl chloride resin-based plastisol paint capable of improving the soundproofing performance by thickening a protective film is disclosed.

[0005]

However, in the above-mentioned conventional method for forming a multilayer coating film, the thickness of the coating film is increased by the multilayer structure, so that the weight of the vehicle body increases and the amount of paint used increases. However, there is a problem that the cost is increased. Also,
Regarding the soundproofing performance of the coating film to which the above foaming agent was added, in the experiment of the present inventor, although the soundproofing performance was improved by the addition of the foaming agent, a satisfactory result was not obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has a single-layer structure, capable of forming a coating film capable of exhibiting good chipping resistance and sufficient soundproofing performance. An object of the present invention is to provide a plastisol composition.

[0007]

A vinyl chloride plastisol composition of the present invention which solves the above-mentioned problems comprises a vinyl chloride polymer resin, a plasticizer and a filler as main components, and contains a liquid asphalt and a foaming agent. It is a feature.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The vinyl chloride plastisol composition of the present invention contains a vinyl chloride polymer resin, a plasticizer and a filler as main components. As the vinyl chloride polymer resin, a vinyl chloride monopolymer, a homopolymer such as vinylidene chloride monopolymer, or a copolymer of a vinyl acetate resin or the like with these resins can be appropriately selected and used. .

As the above-mentioned plasticizer, a general plasticizer for vinyl chloride plastisol can be used. Examples of general plasticizers for vinyl chloride plastisols include phthalate ester, phosphate ester, aliphatic dibasic ester ester and dihydric alcohol ester plasticizers. However, from the viewpoint of improving the soundproofing performance by softening the formed coating film, two types of the above-mentioned phthalate ester plasticizers, in particular, DHP (diheptyl phthalate) and DINP (isononyl phthalate). It is preferable to use the plasticizers at the same time in a specific mixing ratio.
A preferred embodiment of the mixing ratio of DHP and DINP is DH
P: DINP = 1: 3 to 1: 5 by weight. DH
By setting the ratio of DINP to P in the range of 3 to 5, good chipping resistance can be exhibited,
Sufficient soundproof performance can be exhibited. The soundproofing performance can be improved by using DHP and DINP as the plasticizer because the melt viscosity of vinyl chloride plastisol decreases and the expansion ratio increases.
It can be considered that the elasticity of the coating film can be reduced.

The above fillers include calcium carbonate, barium sulfate, calcium oxide, powder fillers such as clay and talc, flake fillers such as mica and graphite, acicular calcium metasilicate, zonolite, potassium titanate. , Rock wool staple fiber, glass fiber staple fiber, aluminum silicate, needle filler such as carbon fiber staple fiber and aramid fiber staple fiber, inorganic hollow filler such as glass balloon, silica balloon and carbon inorganic hollow sphere, and chloride An organic hollow filler such as a plastic balloon made of an organic synthetic resin such as vinylidene or acrylonitrile can be used.

[0011] The vinyl plastisol composition of the present invention is characterized by containing liquid asphalt and a foaming agent. The liquid asphalt is for imparting flexibility to the formed coating film. Asphalt such as straight asphalt and blown asphalt is usually fixed at room temperature, but in the present invention, asphalt which is liquid at room temperature is used. Examples of asphalt that is liquid at room temperature include “Slad TB” (trade name, manufactured by Showa Shell Sekiyu KK).

The amount of the liquid asphalt is preferably 5 to 15 parts by weight based on 100 parts by weight of the vinyl chloride plastisol composition containing a foaming agent.
If the amount is less than 5 parts by weight, sufficient soundproofing performance cannot be imparted. On the other hand, if the amount exceeds 15 parts by weight, chipping resistance may decrease. As the foaming agent,
A foaming agent that generates gas by heating can be used. Bubbles are formed inside the coating film by the generated gas to increase the bulk of the coating film, so that it is possible to reduce the impact sound generated when small stones or the like collide with the coating film. Specific examples include dinitrosopentamethylenetetramine, azodicarbonamide, 4,4'oxybisbenzenesulfonylhydrazide, paratoluenesulfonylhydrazide, paratoluenesulfonylacetone hydrazone, and hydrazodicarbonamide. Further, magnesium hydroxide, urea auxiliary, or the like, which lowers the decomposition temperature of these foaming agents to help generate gas, may be used in combination.

The vinyl chloride plastisol composition of the present invention may contain, in addition to the above-mentioned components, a coloring agent, a high-boiling organic solvent for improving coating workability, and an adhesive for improving the adhesion of the coating film. Can also be added. As a coloring agent, carbon black, titanium white, or the like can be used. As the adhesive, for example, a mixture of one or more resins selected from polyamines, polyamides, polyols, and the like, and a polyisocyanate prepolymer having a terminal NCO group blocked by a suitable blocking agent such as an oxime or a lactam is used. Can be used. As the polyisocyanate prepolymer, xylene diisocyanate, tetramethylene diisocyanate,
Examples thereof include tolylene diisocyanate, phenyl diisocyanate, and methyl xylene diisocyanate.

Further, the use of various known additives such as an antioxidant, a stabilizer, an ultraviolet absorber and a decomposer effective for the vinyl chloride resin composition is not hindered. The vinyl plastisol composition of the present invention having the above structure can be obtained by mixing and dispersing with various conventionally known dispersers. Specific examples of the dispersing machine include a planetary mixer, a kneader, an attritor, a Glenmill, a dissolver, and the like.

The vinyl chloride plastisol composition of the present invention can be applied to a required place by a conventionally known coating method, that is, brush coating, roller coating, air spray coating, electrostatic coating, airless spray coating, or the like. It is possible. However, if a desired coating film thickness is to be obtained on the side of a coating line in the manufacture of automobiles, airless spray coating that can obtain a thick film in a short time is most suitable. The airless spray coating includes improved ones such as electrostatic airless spray coating and air-assisted airless spray coating. In addition, painting by an automatic painting machine controlled by a computer or by a robot painting machine is also possible.

When the vinyl chloride plastisol composition of the present invention is applied to the surface of a steel sheet in a wheel house, a floor back, or the like in a coating line of an automobile manufacturing line,
It can be applied to the surface of the electrodeposited coating film of the steel sheet after the degreasing step, the chemical conversion step and the electrodeposition coating step by the airless spray coating method or the like. Since the vinyl chloride plastisol composition of the present invention contains liquid asphalt in addition to the foaming agent, the coating film obtained from the vinyl chloride plastisol composition has an increased bulk due to the foaming agent, Asphalt increases flexibility. For this reason, the soundproof performance can be sufficiently improved.

[0017] Further, since the bulk of the coating film is increased and the film thickness is increased by the addition of the foaming agent, it is possible to satisfactorily prevent pebbles or the like from breaking through the coating film and damaging the surface to be coated. Demonstrates excellent chipping resistance. On the other hand, since the coating film thickened by the foaming agent has a small density, an increase in the coating film weight due to the thickening can be suppressed. Therefore, according to the vinyl plastisol composition of the present invention,
Even with a single-layer structure, it is possible to form a coating film that can exhibit good chipping resistance and sufficient soundproofing performance.

[0018]

EXAMPLES Examples of the vinyl chloride plastisol composition of the present invention will be specifically described below. (Example 1) The following components were blended in the proportions shown in Table 1 to prepare a vinyl chloride plastisol composition of Example 1, which was mixed and dispersed by a Glenmill to obtain a vinyl chloride plastisol composition of Example 1. A plastisol paint was obtained.

Vinyl chloride polymer resin: Vinyl chloride homopolymer resin (trade name "Zeon 121", Nippon Zeon Co., Ltd.)
Plasticizer: Phthalate ester plasticizer (diheptyl phthalate, trade name "Sansoizer DH")
"P", manufactured by Shin Nippon Rika Co., Ltd.) Filler: calcium carbonate (trade name "Shirayuka CCR", manufactured by Shiraishi Industry Co., Ltd.) and barium sulfate (trade name "Barite BA", Sakai Chemical Co., Ltd.) Colorant: Carbon black (trade name “CB MA ^# 100”, manufactured by Mitsubishi Chemical Corporation) High boiling organic solvent: High boiling point aliphatic solvent (trade name “Isopar L”, manufactured by Exxon Chemical Co., Ltd.) ) Blowing agent: azodicarbonamide Liquid asphalt: “Slad TB” (trade name,
(Showa Shell Sekiyu K.K.) Adhesive (Example 2) This example 2 was carried out in the same manner as in Example 1 except that the blending amount of the liquid asphalt was changed to 8 parts by weight.
Was obtained.

Example 3 A vinyl chloride plastisol paint according to Example 3 was obtained in the same manner as in Example 1 except that the blending amount of the liquid asphalt was changed to 10 parts by weight. Example 4 A vinyl chloride-based plastisol paint according to Example 4 was obtained in the same manner as in Example 1 except that the blending amount of the liquid asphalt was changed to 15 parts by weight.

(Comparative Example 1) DOP (di-2-ethylhexyl phthalate) as a phthalate ester plasticizer (trade name "Sansosizer DOP", manufactured by Shin Nippon Rika Co., Ltd.)
Comparative Example 1 was prepared in the same manner as in Example 1 except that 10 parts by weight was used and no liquid asphalt was blended.
Was obtained.

Comparative Example 2 A comparative example was prepared in the same manner as in Example 1 except that 10 parts by weight of the same DOP as in Comparative Example 1 was used as the phthalic acid ester-based plasticizer, and no blowing agent was added. 2 was obtained. Comparative Example 3 Comparative Example 1 as a phthalate plasticizer
A vinyl chloride-based plastisol paint according to Comparative Example 2 was obtained in the same manner as in Example 1 except that 10 parts by weight of the same DOP was used, and that the blowing agent and the liquid asphalt were not blended.

[0023]

[Table 1]

(Evaluation) Examples 1 to 4 and Comparative Examples 1 to 4
The vinyl chloride-based plastisol paint according to No. 3 was evaluated for soundproofing performance and chipping resistance by the following methods. 1) Soundproofing performance evaluation A 300 mm x 300 mm x 1.6 mm surface of a steel sheet for automobiles is spray-coated with an airless pump,
Each paint is applied in a thickness of 2 mm in a range of 190 mm × 190 mm, and heated at 140 ° C. × 20 minutes by an electric heating furnace.
After cooling, a test coated plate was prepared.

The coated plate was held at an angle of 45 ° with respect to the vertical, and a steel ball having a diameter of 8 mm was dropped from a height of 2 m from the center of the coated plate. The impact sound was measured by a microphone placed horizontally 200 mm away from the center of the coated plate. Table 2 shows the results. The sound was measured under the following conditions.

Frequency: 0 to 12.8 kHz Frequency resolution: 16 kHz Data acquisition time: 125 ms 1/3 octave band data: Narrow band data is converted 2) Evaluation of chipping resistance performance A test painted plate prepared in the same manner as the above soundproof performance evaluation is prepared. -3
Set in a gravelometer (manufactured by Suga Test Instruments Co., Ltd.) in an atmosphere of 0 ° C., and grind the No. 6 crushed stone specified by JIS into 1
Each time, 500 g was sprayed with compressed air to collide with the coating film surface, and this was repeated five times, and the state of the coating film surface thereafter was observed. The results are also shown in Table 2.

[0027]

[Table 2] As is clear from Table 2, the coating films obtained from the coating materials according to Examples 1 to 4 to which the liquid asphalt and the foaming agent were added had good chipping resistance, and no liquid asphalt was added. As compared with Comparative Example 1, Comparative Example 2 in which no foaming agent was added, and Comparative Example 3 in which liquid asphalt and the foaming agent were not added, the soundproofing performance was also sufficiently improved.

Comparative Example 2 in which no blowing agent was added
In, even though liquid asphalt was added, almost no improvement in soundproofing performance due to the addition of liquid asphalt was recognized. This is probably because a bulky coating film due to foaming was not obtained. On the other hand, in Examples 1 to 4 in which the liquid asphalt and the foaming agent were added, in addition to the improvement of the soundproofing performance by the addition of the foaming agent, the coating film could be made more flexible by the addition of the liquid asphalt. Therefore, it is considered that the soundproofing performance has been dramatically improved.

[0029]

As described in detail above, according to the vinyl chloride plastisol composition of the present invention, even if it has a single-layer structure,
It is possible to form a coating film that can exhibit good chipping resistance and sufficient soundproofing performance. Therefore, the vinyl chloride plastisol composition of the present invention is applied to the back of the floor, the side sill, the wheel house, the front apron, the front and rear fenders and the lower part of the door of the automobile, thereby increasing the amount of paint used. It offers superior soundproofing performance compared to conventional models while suppressing height and weight increases, contributing to creating a comfortable cabin environment.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Junki Ishiyama 8-16-15 Toshima, Kita-ku, Tokyo Inside Japan Special Paint Co., Ltd.

Claims (1)

[Claims] 1. A vinyl chloride plastisol containing a vinyl chloride polymer resin, a plasticizer and a filler as main components,
A vinyl chloride plastisol composition comprising liquid asphalt and a blowing agent.