JPH0717801B2 - Plastisol composition having damping properties - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is applied to a chipping-resistant paint such as an undercoat for automobiles, a floor part of an automobile where a bituminous sheet-like damping material has been conventionally used. The present invention relates to a coating type damping material that can be used.

[Conventional technology]

Conventionally, anti-chipping paint is applied to the underfloor and other parts of automobiles for the purpose of protecting the vehicle body from scratches caused by pebbles and gravel, etc., that are splashed by the tires of own vehicle and other vehicles while traveling, so-called chipping phenomenon. Was applied.

Initially, a coating material (product name Underseal) was developed by mixing a bituminous material with a filler, a solvent, etc., but this was because the binder component was mainly composed of the bituminous material.
It had the drawback of poor cold chipping resistance in winter. However, this type had a certain level of anti-chipping performance and vibration damping performance.

Next, in order to improve the anti-chipping performance in the winter, a vinyl chloride undercoat was developed in which a vinyl chloride resin was sol-ized with a plasticizer such as DOP, and fillers, additives, adhesion promoters, etc. were mixed. It was Since this type also has excellent cold chipping resistance, it is now widely used for the purpose of rust prevention in automobiles, but it is inferior to the bituminous underseal in vibration damping.

On the other hand, on the floor and dash of the car interior,
Melsheet (registered trademark) is used in which a bituminous material is mixed with a filler, a synthetic resin, an additive and the like, and kneaded to form a sheet for the purpose of damping vibration.

The sheet is placed at a predetermined position in a coating line of an automobile, and is fused to a steel plate by heat when passing through a baking / drying oven for coating, and exhibits vibration damping properties.

[Problems to be Solved by the Invention]

If it is possible to add vibration control to the undercoat material that is a chipping resistant paint, the vehicle will be provided with vibration control in addition to rust prevention to provide a more comfortable environment for passengers inside the vehicle. You can

On the other hand, by using such a coating type damping material in the area where the conventional sheet type damping material was used, the work placed manually by the worker can be performed by the use of the painting robot. It has the advantage of being automated.

For the reasons described above, under the present circumstances, development of an undercoat material having vibration damping property is desired.

[Means for Solving the Problems]

In order to solve the above problems, the present inventors have earnestly studied, as a result, a vinyl chloride plastisol composition having a specific composition,
By solving all of the above problems, the inventors have succeeded in developing a vinyl chloride plastisol composition having both anticorrosive performance and vibration damping performance. Therefore, the gist of the present invention is: 1. A vinyl chloride plastisol composition having a vinyl chloride polymer or copolymer resin, a plasticizer, and a filler as a main component, with respect to 100 parts by weight of the vinyl chloride resin. Cross-linking aid 5-4
0 parts by weight, organic peroxide 0.02 to 0.5 parts by weight, foaming agent 2 to 20
A vinyl chloride plastisol composition, characterized by containing parts by weight.

2. The vinyl chloride plastisol composition according to claim 1, which contains a flaky filler and a needle filler.

3. The vinyl chloride plastisol composition according to claim 1, further comprising a hollow filler.

Exist in.

A vinyl chloride plastisol composition in which a polymer of a vinyl chloride resin or a copolymer with another resin is dispersed in a suitable plasticizer, and a filler, a colorant, various additives, and optionally a solvent are mixed therein is known. . This vinyl chloride plastisol is widely applied as a "chipping resistant undercoat" mainly on the underside of automobiles in order to prevent pebbles and gravel that wind up from tires when the car is running from scratching the body and causing rust. ing.

The present inventors have succeeded in increasing the coating film of the undercoat by foaming, increasing the elastic modulus and sliding friction of the coating film, and imparting damping properties to the undercoat by their synergistic effect. It was done.

The vinyl chloride resin is used by appropriately selecting from homopolymers such as vinyl chloride monopolymer and vinylidene chloride monopolymer, and copolymers with vinyl acetate resin and the like.

Plasticizers include phthalate ester plasticizers such as DOP, DEP, DBP and DMP, phosphate ester plasticizers such as TEP and TCP, other aliphatic monobasic acid esters, aliphatic dibasic acid esters, and dihydric alcohols. It is used by appropriately selecting it from an ester or the like.

As the filler, calcium carbonate, barium sulfate, calcium oxide, clay, in addition to the powdery filler such as talc is appropriately selected and used, in addition, flaky filler, needle-like filler, hollow filler described later. Use is also recommended.

Carbon black, titanium dioxide or the like can be used as the colorant.

In order to improve coating workability, some parts by weight of solvent may be added.

The additive may be appropriately selected and used from adhesion imparting agents such as polyamide and block isocyanate, dispersants, defoaming agents, stabilizers and thixotropy imparting agents.

The essential formulations for the vinyl chloride plastisol composition of the present invention are described below.

The cross-linking aid is for increasing the cross-linking efficiency of the cross-linking reaction of the vinyl chloride resin, and the addition of the cross-linking aid increases the elastic modulus of the vinyl chloride plastisol coating film and improves the vibration damping property. Examples of the crosslinking aid that can be used include polyfunctional monomers having one or more double bonds such as diallyl phthalate, ethylenediamine methacrylate, triallyl isocyanurate, and trimethylolpropane trimethacrylate. Vinyl chloride resin 10
5 to 40 parts by weight is essential for 0 parts by weight. If the amount is less than 5 parts by weight, the crosslinking reaction does not proceed sufficiently, and even if the amount is more than 40 parts by weight, the crosslinking is not promoted in proportion to the compounding amount, which is rather disadvantageous in terms of cost.

Similar to the cross-linking aid, the organic peroxide is also for increasing the cross-linking efficiency of the cross-linking reaction of the vinyl chloride resin, and various kinds are known, but as the organic peroxide that can be used in the present invention, Two types of peroxyketals and dialkyl peroxides, which have relatively high stability of radicals generated by thermal decomposition, are recommended. The compounding amount is required to be 0.02 to 0.5 parts by weight with respect to 100 parts by weight of the vinyl chloride resin. If the amount is less than 0.02 part by weight, the crosslinking reaction does not proceed sufficiently, and even if the amount exceeds 0.5 part by weight, the crosslinking is not promoted in proportion to the compounding amount, which is rather disadvantageous in terms of cost.

In order to increase the film thickness of the vinyl chloride plastisol coating film by foaming and improve the vibration damping property, the blending of the foaming agent is essential. Examples of the foaming agent that can be used include dinitrone pentamethylene tetramine, azodicarbonamide, 4,4'oxybisbenzenesulfonyl hydrazide, paratoluenesulfonyl hydrazide, paratoluenesulfonylacetone hydrazone and hydrazodicarbonamide. Vinyl chloride resin
2 to 20 parts by weight is essential for 100 parts by weight. If it is less than 2 parts by weight, the foaming of the coating film is insufficient and the object cannot be achieved. If it is blended in excess of 20 parts by weight, the density of the coating film is unnecessarily reduced, and the coating film has chipping resistance and the like. There is a risk that the physical properties will deteriorate.

In order to lower the decomposition temperature of the organic foaming agent, it is possible to use a urea auxiliary agent together.

Moreover, as a method of improving the vibration damping performance, it is recommended to add a flaky filler or a needle filler to the filler.

Examples of the flaky filler include mica and graphite.

As the needle-shaped filler, needle-shaped calcium metasilicate,
Examples include zonolite, potassium titanate, rock wool short fibers, glass fiber short fibers, aluminum silicate, carbon fiber short fibers, and aramid fiber short fibers.

Furthermore, in order to reduce the specific gravity of the coating film and reduce the weight of the entire coating film, it is recommended to add a hollow filler to the filler.

The hollow filler is a filler having a substantially spherical interior and a hollow interior, such as glass balloons, silica balloons, shirasu balloons, inorganic hollow fillers such as carbon inorganic hollow spheres, vinyl chloride resin, vinylidene chloride. An organic plastic balloon which is made of resin, acrylic resin or other synthetic resin as a raw material and expands when heated can be exemplified.

The plastisol composition having the above composition is produced by stirring, kneading and dispersing with a conventionally known coating dispersion agitator such as a kneader, planetary mixer, three rolls, dissolver, paint shaker. It is also possible to include a defoaming step.

The plastisol composition produced is an airless spray,
Air spray, mini bell, rotary coating machine, electrostatic coating machine,
It is applied by a conventionally known coating means such as spatula coating or brush coating.

Since the plastisol composition according to the present invention has deep vibration damping performance in addition to chipping resistance, it has been conventionally coated with a chipping resistant paint, automobile floor floor, rocker panel part, front side, rear fender part, front side. In addition to the apron, etc., it can also be applied to the floor, dash panel, tunnel in the center of the floor, door panel, etc., where the bituminous damping sheet was conventionally installed.

The plastisol composition of the present invention is applied in the middle of an automobile coating line and heated at 100 ° C to 160 ° C for 10 minutes to 40 minutes to form a coating film.

[Action]

The plastisol composition of the present invention has a vibration-damping performance remarkably increased by the foaming agent increasing by about 1.2 times to 3.0 times, preferably 1.5 to 2.0 times, the dry coating film of the conventional vinyl chloride plastisol composition. .

Further, the use of the organic peroxide and the cross-linking aid accelerates the cross-linking reaction of the vinyl chloride resin, thereby significantly increasing the elastic modulus of the resulting coating film, which also contributes to the improvement of the vibration damping performance.

In addition, it is possible to further improve the vibration damping performance by adding a flaky filler and a needle-like filler to the filler. On the other hand, by adding a hollow filler, the specific gravity of the coating film can be improved. Lower.

〔Example〕

Examples will be given below to provide a more detailed understanding of the present invention.
Naturally, the invention is not limited to the following examples.

100 parts by weight of vinyl chloride resin (Zeon 121: made by Nippon Zeon), 120 parts by weight of plasticizer (DOP: made by Shin Nippon Rika), 5 parts by weight of calcium oxide, calcium carbonate (MC-5: made by Maruo Calcium) 150 parts by weight and 30 parts by weight of cellosolve acetate (manufactured by Daicel Chemical Industries, Ltd.) were mixed and dispersed with an open kneader to obtain a vinyl chloride plastisol compounding base.

Example 1 5 parts by weight of ethylenediamine methacrylate, 0.02 part by weight of di-t-butyl peroxide and 2 parts by weight of paratoluenesulfonyl hydrazide were added to the compounding base and mixed and dispersed.

Example 2 15 parts by weight of mica and 10 parts by weight of acicular calcium metasilicate were added to the compounding base, and then the same additives as in Example 1 were added and mixed and dispersed.

Example 3 After adding 20 parts by weight of a silica balloon to the compounding base, the same additives as in Example 1 were added and mixed and dispersed.

Comparative Example The formulation base was mixed and dispersed as it was.

〔Test method〕

The vinyl chloride plastisol composition used in each of the examples and comparative examples was applied to an automobile steel sheet having a thickness of 0.8 mm by an airless spray coating machine so as to have a coating film thickness of 1.0 mm.

The coated plate was baked and dried at 140 ° C. for 20 minutes and cooled to be used as a sample.

Vibration damping test The loss coefficient η at each temperature of 20 ° C., 40 ° C. and 60 ° C. was obtained for each sample by the resonance method (see page 438 of “Handbook for Noise Control” published by The Japan Acoustical Material Association). It is recognized that the larger the number of the loss coefficient η, the higher the damping effect.

Chipping resistance test 500 g of crushed No. 6 crushed stone with a painted test plate
The state of scratches was observed by spraying 5 times at a pressure of 5 kg / cm ² No scratches: ○ Interlayer peeling: △ Interfacial peeling: × [Results] Table 1 shows the results of each test.

(Effects of the Invention) The vinyl chloride plastisol composition according to the present invention exhibits, in addition to chipping resistance, damping performance equivalent to or better than that of a bituminous sheet-shaped damping material, thereby providing a more comfortable environment for vehicle occupants. Can be provided. Furthermore, since the construction of the damping material can be done by painting, it can be automated by a robot.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area C09D 127/04 PFE // F16F 15/02 9138-3J

Claims (3)

[Claims] 1. A vinyl chloride plastisol composition comprising a vinyl chloride polymer or copolymer resin, a plasticizer, and a filler as main components, wherein the crosslinking aid is 5 to 100 parts by weight of the vinyl chloride resin. 40 parts by weight, organic peroxide 0.02-0.5 parts by weight,
A vinyl chloride plastisol composition comprising 2 to 20 parts by weight of a foaming agent. 2. The vinyl chloride plastisol composition according to claim 1, which contains a flaky filler and a needle filler. 3. The vinyl chloride plastisol composition according to claim 1, which contains a hollow filler.