JPH04145174A - Vibration-damping plastisol composition - Google Patents

Abstract

PURPOSE:To obtain a plastisol composition having chipping resistance and vibration-damping performance by using a vinyl chloride resin, a plasticizer and a filler as main components and compounding specific amounts of a crosslinking assistant, an organic peroxide and a foaming agent. CONSTITUTION:The objective plastisol composition is composed mainly of (A) a vinyl chloride polymer or copolymer resin, (B) a plasticizer such as dioctyl phthalate and (C) a filler such as calcium carbonate and talc and further contains (D) 5-40 pts.wt. (based on 100 pts.wt. of the vinyl chloride resin of the component A) of a crosslinking assistant such as diallyl phthalate, (E) 0.02-0.5 pts.wt. of an organic peroxide such as peroxyketal or dialkyl peroxide and (F) 2-20 pts.wt. of a foaming agent such as dinitrosopentamethylenetetramine. The component C is preferably flaky or acicular filler.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to chipping-resistant coatings such as undercoats for automobiles, and to floor parts of automobiles where bituminous sheet vibration damping materials have conventionally been used. This invention relates to a coating-type vibration damping material that can be used.

[Conventional technology]

Traditionally, chipping-resistant paint has been applied to the underside and other parts of automobiles in order to protect them from the so-called chipping phenomenon, which is the damage caused by pebbles and gravel thrown up by the tires of own troops or other vehicles while driving. It had been painted.

Initially, a coating material (trade name: UNDER SEAL) was developed that was a mixture of bituminous material, filler, solvent, etc., but this was because the binder component was mainly bituminous material.
It had the disadvantage of low cold resistance and low chipping performance in winter. However, this type had not only chipping resistance but also a certain degree of vibration damping performance.

Specifically, to improve chipping resistance in winter.

A vinyl chloride undercoat has been developed in which a vinyl chloride resin is made into a sol with a plasticizer such as DOP, and fillers, additives, adhesion promoters, etc. are blended therein. This type has excellent cold chipping resistance and is now widely used for rust prevention purposes in automobiles, but its vibration damping properties are inferior to bituminous underseals.

On the other hand, in the floor and dash parts of the car interior,
For the purpose of damping vibrations, Melsheet (registered trademark) is used, which is a mixture of bituminous materials, fillers, synthetic resins, additives, etc., which is kneaded and formed into a sheet.

The sheet is placed at a predetermined location on an automobile painting line, and the baked paint is fused to the steel plate by the heat generated when passing through a drying oven, exhibiting vibration damping properties.

[Problem to be solved by the invention]

If damping properties can be imparted to the undercoat material, which is a chipping-resistant paint, automobiles will be provided with vibration damping properties in addition to rust prevention properties, thereby providing a more comfortable environment for vehicle occupants. I can do it.

On the other hand, by using such coating-type damping materials in areas where conventional sheet damping materials were used, the work that used to be done manually by workers can be replaced by the use of painting robots. It has the advantage of being automated.

For the reasons mentioned above, the current situation is that there is a long-awaited development of an undercoat material having vibration damping properties.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present inventors have conducted extensive research and found that a vinyl chloride plastisol composition with a specific formulation enables
We have succeeded in developing a vinyl chloride plastisol composition that has solved all of the above problems and has both anti-corrosion performance and vibration damping performance.

Therefore, the gist of the present invention is as follows: 1. A vinyl chloride plastisol composition containing a vinyl chloride polymer or copolymer resin, a plasticizer, and a filler as main components, with respect to 100 parts by weight of the vinyl chloride resin. It is characterized by containing 5 to 40 parts by weight of a crosslinking aid, 0.02 to 0.5 parts by weight of an organic peroxide, and 2 to 20 parts by weight of a blowing agent.
Vinyl chloride plastisol composition.

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

3. The vinyl chloride plastisol composition according to claim 1, which contains a hollow filler.

exists in

Vinyl chloride plastisol compositions are known, in which a polymer of vinyl chloride resin or a copolymer with other resins is dispersed in a suitable plasticizer, and fillers, colorants, various additives, and optionally a solvent are blended therein. . This vinyl chloride plastisol is widely applied as a chipping-resistant undercoat, mainly on the underside of automobile floors, in order to prevent the pebbles and gravel thrown up by tires when the car is running from hitting the car body, causing scratches and rust. has been done.

The present inventors increased the paint film of the undercoat through foaming, increased the elastic modulus and sliding friction of the paint film, and succeeded in imparting vibration damping properties to the undercoat through the synergistic effect of these. This is what I did.

The vinyl chloride resin is appropriately selected from homopolymers such as vinyl chloride monopolymers, vinylidene chloride monopolymers, and copolymers with vinyl acetate resins.

Plasticizers include phthalate plasticizers such as DOP, DEP, DBP, and DMP, phosphate plasticizers such as TEP and TCP, and other aliphatic-basic acid esters, aliphatic dibasic acid esters, and dihydric alcohols. It is appropriately selected and used from esters and the like.

The filler may be appropriately selected from powder fillers such as calcium carbonate, barium sulfate, calcium oxide, clay, and talc, as well as scale-like fillers, needle-like fillers, and hollow fillers described below. Also recommended for use.

As the coloring agent, carbon black, titanium dioxide, etc. can be used.

In order to improve painting workability, a solvent for the powder molding part may be added.

The additives can be appropriately selected from adhesion agents such as polyamides and blocked isocyanates, dispersants, antifoaming agents, stabilizers, thixotropy agents, and the like.

The essential ingredients for the vinyl chloride plastisol composition of the present invention are explained below.

The crosslinking aid is used to increase the crosslinking efficiency of the crosslinking reaction of the vinyl chloride resin, and by adding the crosslinking aid, the elastic modulus of the vinyl chloride plastisol coating film is increased and vibration damping properties are improved. Examples of crosslinking aids that can be used include polyfunctional monomers having one or more double bonds, such as diallyl phthalate, ethylenediamine methacrylate, triallyl isocyanurate, and trimethylolpropane trimethacrylate. The blending amount is vinyl chloride resin 1
00 parts by weight, 5 to 40 parts by weight is essential. If the amount is less than 5 parts by weight, the crosslinking reaction will not proceed sufficiently, and even if it is added in excess of 40 parts by weight, crosslinking will not be promoted in proportion to the amount added, which is rather disadvantageous in terms of cost.

Similar to crosslinking aids, organic peroxides are used to increase the crosslinking efficiency of the crosslinking reaction of vinyl chloride resins, and various types are known, but organic peroxides that can be used in the present invention include: Two types are recommended: peroxyketal and dialkyl peroxide, which have relatively high stability of radicals generated by thermal decomposition. The blending amount is essentially 0.02 to 0.5 parts by weight per 100 parts by weight of the vinyl chloride resin. If the amount is less than 0.02 parts by weight, the crosslinking reaction will not proceed sufficiently, and even if it is added in excess of 0.5 parts by weight, crosslinking will not be promoted in proportion to the amount added, and it will be more expensive in terms of cost. It is disadvantageous.

In order to increase the thickness of the vinyl chloride plastisol coating film by foaming and improve the damping properties, it is essential to include a foaming agent. Examples of blowing agents that can be used include dinitrosopentamethylenetetramine, azodicarbonamide, 4,4'oxybisbenzenesulfonylhydrazide, paratoluenesulfonylhydrazide, paratoluenesulfonylacetone hydracine, and hydrazodicarbonamide. . The blending amount is vinyl chloride resin 1
00 parts by weight, 2 to 20 parts by weight is essential. If it is less than 2 parts by weight, the foaming of the coating film will be insufficient and the objective cannot be achieved, and if it exceeds 20 parts by weight, the density of the coating film will be lowered more than necessary, and the coating film will have poor chipping resistance. There is a risk that physical properties may deteriorate.

In order to lower the decomposition temperature of the organic blowing agent, it is also possible to use a urea adjuvant or the like in combination.

Furthermore, as a method for improving vibration damping performance, it is recommended to add scale-like filler or needle-like filler to the filler.

Examples of the flaky filler include mica and graphite.

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

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.

Hollow fillers are spherical fillers that are hollow inside, and include inorganic hollow fillers such as glass balloons, silica balloons, shirasu balloons, carbon inorganic hollow spheres, vinyl chloride resin, and chloride. Examples include organic plastic balloons that are made from vinylidene resin, acrylic resin, and other synthetic resins and expand when heated.

The plastisol composition according to the above formulation is produced by stirring, mixing, and dispersing using a conventionally known paint dispersion stirrer such as a kneader, planetary mixer, triple roll, day silver, or paint shaker. It is also possible to include a defoaming step.

The produced plastisol composition can be used as an airless spray,
Air spray, mini bell, rotary paint sprayer.

The coating is applied by conventionally known coating means such as an electrostatic coating machine, spatula coating, and brush coating.

The plastisol composition of the present invention has vibration damping performance in addition to chipping resistance, so it can be applied to areas where chipping-resistant paint has been conventionally applied, such as the underside of automobile floors, rocker panels, front and rear fenders, and parts of front and rear fenders. In addition to areas such as aprons, it can also be applied to interior floor areas, dash panels, tunnels in the center of the floor, door panels, etc. where bituminous vibration damping sheets have traditionally been applied.

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

[Effect]

The plastisol composition of the present invention uses a blowing agent to provide approximately 1.2% of the dry coating film of conventional vinyl chloride plastisol compositions.
By increasing the vibration damping performance by a factor of 3.0 to 3.0, preferably 1.5 to 2.0, the damping performance is significantly increased.

Furthermore, the use of an organic peroxide and a crosslinking aid promotes the crosslinking reaction of the vinyl chloride resin, thereby significantly increasing the elastic modulus of the resulting coating film, which also contributes to improved vibration damping performance.

In addition, by blending scale-shaped fillers and needle-shaped fillers with the filler, it is possible to further improve vibration damping performance, while by blending hollow fillers, the specific gravity of the coating film can be improved. decrease.

〔Example〕

Examples are given below to provide a more detailed understanding of the present invention.

Naturally, the present invention is not limited to the following examples.

Vinyl chloride resin (Zeon 121: manufactured by Nippon Zeon Co., Ltd.) 1
00 parts by weight, plasticizer (DOP: manufactured by Shin Nihon Rika Co., Ltd.) 120
parts by weight, 5 parts by weight of calcium oxide, calcium carbonate (M
C.-5: 150 parts by weight (manufactured by Maruo Calcium Co., Ltd.) and 30 parts by weight of cellosolve acetate (manufactured by Daicel Chemical Co., Ltd.) were mixed and dispersed in an open kneader to obtain a blended base for vinyl chloride plastisol.

Example 1 5 parts by weight of ethylenediamine methacrylate, 0.02 parts by weight of di-t-butyl peroxide, and 2 parts by weight of para-toluenesulfonyl hydrazide were added to the blended base,
Mixed and dispersed.

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

Example 3 After adding 20 parts by weight of silica balloon to the blend base,
Additives similar to those in Example 1 were added and mixed and dispersed.

Comparative example The blended base was mixed and dispersed as it was.

〔Test method〕

The vinyl chloride plastisol compositions of each of the Examples and Comparative Examples were coated onto a 0.8 m thick automobile steel plate using an airless spray coating machine to a coating film thickness of 1.0++e.

The painted board was baked and dried at 140°C for 20 minutes, and after cooling, it was used as a test sample.

■Vibration damping test Each sample was tested at 20°C, 40°C, and
The loss coefficient η at each temperature of 60″C was determined. It is recognized that the larger the loss coefficient η, the higher the vibration damping effect.

■Chipping resistance test Painted test plate was tested with No. 6 crushed stone 500 using a gravelometer.
5 times at a pressure of 5 kg/J, and the appearance of damage was observed: No damage: 20 Glabella peeling: Δ Interfacial peeling: X [Results] The results of each test are shown in Table 1.

Table 1 [Effects of the Invention] In addition to chipping resistance, the vinyl chloride plastisol composition of the present invention exhibits vibration damping performance equivalent to or higher than that of bituminous sheet damping materials, thereby providing more comfortable vehicle occupants. environment can be provided. Furthermore, since the damping material can be applied by painting, automation using robots is possible.

Claims (1)

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