JP3390643B2 - Undercoat agent for noise prevention - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention
Prevents noise caused by rock splashes from the wheel house panel
Noise suitable as an undercoat for places to be stopped
It relates to an undercoat agent for prevention. 2. Description of the Related Art Automobiles
Running in the back of the floor and in the wheel house (tire house)
Stone splashes and sand splashes often occur in the inside, and the driver
Generates unusual noise. [0003] Conventionally, such rock and pop noises are prevented.
As a method of stopping, the back of the car floor or the wheel house
Panel of non-foamed vinyl chloride resin (PV
C) Foaming ratio 50% before using paint or unexpanded balloon
The low-foaming vinyl chloride resin (PVC) paint
-It has been used as a coating agent. However, the former non-foamed PVC is used.
In the case, if the coating layer is thicker, the effect of reducing stone and sand noise
However, the cost is high and the work by increasing the application amount
Efficiency is reduced and vehicle weight is increased due to increase in coating weight.
Great. [0005] On the other hand, the latter uses an uninflated balloon.
When foamed PVC paint is used, non-foamed PVC paint
The effect of increasing the thickness of the coating layer compared to that of
Up, but foam using an uninflated balloon becomes a foaming agent
The film becomes harder than the foam produced by the
The effect of absorbing shock is reduced, and the soundproofing effect is inferior. Also,
Rune film reduces cushioning and chipping resistance
Decreases extremely. In this case, extreme chipping resistance
For the decrease, improve the physical properties of the compound
(Eg low filling of uninflated balloon, vinyl chloride
Increase the vinyl acetate copolymer ratio)
Although a certain level value is secured, it is still not enough
No. Also, because it is used in automobile production lines,
Is required to have a heat resistance of 130 to 160 ° C.
The material of the inflation balloon is acrylonitrile with good heat resistance
Polymer alone or acrylonitrile-vinylidene chloride
A copolymer with a high acrylonitrile ratio is used.
You. However, vinylidene chloride has poor heat resistance,
As the nitrile ratio increases, the acrylonitrile monomer
Content rate increases, which is
No. [0007] From such a point, foaming using an organic foaming agent
Type PVC paints are desirable,
In addition to noise reduction,
Excellent chipping resistance, can form a coating film with good adhesion,
Excellent sprayability in terms of workability
Is required. Means for Solving the Problems and Embodiments of the Invention
The present invention has been made to meet the above-mentioned demands, and
Average particle size of primary particles is less than 5μm as vinyl resin
Then, a part thereof is agglomerated to mix secondary particles with primary particles.
Use a vinyl chloride resin that has been
By combining with filler and plasticizer, the above purpose is achieved.
It is a thing. That is, the present invention relates to a vinyl chloride resin and an organic resin.
An anti-noise amplifier that contains a foaming agent, plasticizer, and filler
In the dark coat agent, the vinyl chloride resin
Primary particles having a particle size of 5 μm or less, and aggregates of the primary particles
Chloride made of secondary particles having an average particle size of 100 μm or less
Characterized in that it contains at least 50% by weight of benzyl resin particles.
Provide an undercoat agent for noise prevention. [0010] The undercoat agent of the present invention is used for an automobile floor.
For stone splashes and sand splashes such as panels on the back and wheel house
Apply an undercoat film to the places where noise due to
Used to form, it has a single layer effect
In addition to the existing automotive painting process.
It can be incorporated without change,
Especially in this painting process, excellent spray workability
Excellent chipping resistance and adhesion, good noise prevention effect
It gives a good coating. A plasticizer or a foaming agent is added to the vinyl chloride resin.
And the method of foaming by heating
Kaihei 1-287147, Tokuhei 6-18916, Tokuhei
It is a technique known by Japanese Patent Application Laid-Open No. 7-330937.
You. However, it can be used for the floors of automobiles, tire houses, etc.
In undercoating agent, chipping with stone splash
Nothing is aimed at noise reduction, especially for this purpose.
To achieve this, use organic blowing agents and
The current automobile production line using a specific amount of filler and plasticizer
Conditions that can be applied to
Of the present invention which provides excellent effects such as storage stability and soundproofing effect.
The undercoat agent was discovered by the present inventors for the first time.
is there. Hereinafter, the present invention will be described in more detail.
The noise-prevention undercoat agent of the present invention is a vinyl chloride-based undercoat agent.
Using resin as base polymer, organic foaming agent, necessary
More foaming aid, filler and plasticizer are blended,
As necessary, blending of adhesive components, moisture absorbents, stabilizers, coloring agents, etc.
It is a thing. Here, a vinyl chloride resin (PVC) is used.
Is mainly composed of vinyl chloride homopolymer and vinyl chloride.
And other copolymerizable monomers such as vinyl acetate.
(Vinyl chloride content 50% by weight or less)
Above, especially 70% by weight) alone or in combination of two or more
Can be used in combination. In this case, as the PVC, the average of the primary particles is used.
Uniform particle size is 5 μm or less, preferably 3 μm or less, more preferably
Or 1.5 μm or less, a part of which is
A mixture of secondary particles and secondary particles is used. Where primary
PVC having a large average particle diameter of more than 5 μm
Use not only reduces chipping resistance, but also
Abnormal foaming occurs, which is not preferable in appearance. The above PVC is one of primary particles having a small particle size.
Part is agglomerated in the manufacturing process to obtain secondary particles.
Secondary particles obtained by aggregating small primary particles and part of them
Particles are mixed, the primary particle side and
It has a peak on the secondary particle side and
PVC is composed of two types of PVC having different average particle sizes.
Are mixed. In addition, the above-mentioned PVC smell
The peak on the secondary particle side is preferably 100 μm or less, more preferably
3 to 30 μm, especially 5 to 20 μm
Is preferred. If the average particle size exceeds 100 μm, the particle size becomes coarse
The polyvinyl chloride paste sol is sprayed.
-Chips are liable to be jammed at the time of application and workability is reduced.
In addition, the surface of the coated material lacks smoothness,
The view becomes worse, which is not desirable. Also, in this PVC
The proportion of secondary particles in the mixture is 20 to 90% by weight, especially 40 to 8% by weight.
It is preferably 0% by weight. Such PVC
For example, as a commercially available product manufactured by Huls E
-7031 or the like can be used. PVC in which the above primary particles and secondary particles are mixed
Has good swelling gelling property, workability and foam P
It is preferable from the viewpoint of the physical properties of VC. That is, PVC
Improve the spraying workability of the metal (increase thixotropy)
Therefore, PVC with a large particle size is added to PVC with a small particle size.
When blended, these large and small particle sizes
A relatively large number of particles with an intermediate particle size will be scattered.
As a result, viscosity reduction due to shearing is hindered, and thixotropic
Lopic properties decrease. On the other hand, the primary
PVC with some particles agglomerated and secondary particles mixed
Is low in particles with medium size,
It shows a viscosity increase and a thixotropic phenomenon. Therefore,
In case of spray application, high shear area 10000 sec ^-1 ~
40000 sec ^-1 ) Gives good sprayability, but only
Coatings that are not in a sheared state after spraying have high viscosity and sag
There is no elephant, and the shape is maintained in a vertical portion or the like.
In other words, regarding the gelling property, the secondary particles are originally primary
Because it is an aggregate of particles (agglomerates), the performance of primary particles
Good swelling gelling property and storage stability.
Then, since the secondary particles are strong aggregates,
Prevents swelling with sol
Good stability. Further, PVC has an average degree of polymerization of 25.
00 or less, preferably 2000 or less, more preferably 1 or less.
Desirable is 900 or less. Average degree of polymerization is too high
This is because the physical properties of foamed PVC, such as chipping resistance, decrease.
May be present. The lower limit of the average degree of polymerization is usually 50.
0, preferably 850, more preferably 1000
You. As the above copolymer, vinyl chloride-vinegar is used.
Acid vinyl copolymer is suitable for swelling and gelling
However, this vinyl chloride-vinyl acetate copolymer
Having a vinyl acetate content of 1 to 15% by weight,
0% by weight is preferred. In this case, vinyl chloride homo
Polymer has vinyl chloride-vinyl acetate adhesion on metal surface
Somewhat inferior to copolymers, while vinyl chloride-vinyl acetate
Nyl copolymer has good swelling and gelling properties against plasticizer
Good adhesion by heating, but high cost
Therefore, it is preferable to use both. The combination discount
Is selected as appropriate, but vinyl chloride homopolymer: chloride
Vinyl-vinyl acetate copolymer = 4: 1 to 1: 4 (weight
Ratio). Further, as a copolymer, -CH _Two ROH
Crosslinkable copolymers with groups can also be used. This
This is because the OH group is a block as an adhesion component described later.
Reacts with isocyanate during heating to form urethane bond
To improve adhesion and water resistance. In the present invention, the primary particles may be replaced by secondary particles.
PVC with a mixture of fibers may be used alone, but if necessary
From the standpoint of noise reduction, especially with normal PVC.
Can be In this case, the ratio is the former primary particle
50% by weight or more, especially 7%
Preferably 0% by weight, less than 50% by weight
And the spray workability decreases. Next, in the present invention, it is used for foaming PVC.
There are no particular restrictions on the organic blowing agent
Decomposition temperature in terms of using without changing the painting process
If the blowing agent or blowing agent mixture is at 130-180 ° C
It is preferable to use a mixture of a blowing agent and a foaming aid.
New If the decomposition temperature exceeds 180 ° C,
Does not foam well at a temperature of 60 ° C, while 130 ° C
Those with lower decomposition temperatures are gaseous before the PVC cures.
Omission occurs and good foamed PVC cannot be obtained.
In some cases, the qualities are also poor. Specifically, 4,4'-oxo is used as a foaming agent.
Shibis (benzenesulfonyl hydrazide (OBSH)
Can be preferably used, p-toluenesulfonyl azide, p-toluenesulfonyl azide
-Methylurethanebenzenesulfonyl hydrazide, etc.
Can also be used. Also, as a foaming agent mixture
Is the reaction between OBSH and azodicarbonamide (ADCA)
Mixtures and the like can be mentioned as suitable ones. Change
In addition, the decomposition temperature alone is 180 ° C like ADCA
Decomposition temperature by using together with foaming aid
That is adjusted to 130 to 180 ° C.
Can be. Note that the decomposition temperature of OBSH or the like is 130 to 1
Foaming aids for foaming agents and foaming agent mixtures in the range of 80 ° C
As long as the decomposition temperature is between 130 and 180 ° C
Is not a problem. As the foaming auxiliary, use a known one.
And various metal oxides (eg, zinc oxide,
Gnesium, etc.), metallic soaps (eg, stearic acid
Lead), urea compounds, amines and the like. Note that this
Such foaming aids can be mixed at the same time for other purposes.
Can be. For example, metal soap is used for calcium carbonate
It is used as a surface treatment agent for inorganic fillers.
Metal soap used as a surface treatment agent
As long as it lowers the decomposition temperature,
It is. The compounding amount of the above-mentioned organic foaming agent is
1 to 3 parts for 00 parts (weight part, same hereafter)
And more preferably a blowing agent or a blowing agent mixture
1 to 2.5 parts, especially 1.5 to 2.5 parts, foaming aid 0 to 1
5 parts, especially 1 to 10 parts. In the present invention, as the filler,
Lucium, barium sulfate, clay, diatomaceous earth, silica,
And one of these alone or in combination of two or more.
Can be used in combination. Also if necessary
Mixed with hollow particles such as glass balloons and resin balloons
You can also. In this case, in particular, surface-treated calcium carbonate
It is preferable to use a surface-treated inorganic filler such as
And the average particle size of the inorganic filler is 0.01 to 1 μm.
0.02 to 0.1 μm, specific surface area by BET method
Is 5-30m ^Two / G, especially 15 to 25 m ^Two / G is preferred
Good. Use fine surface treatment filler
By not adding it, uniform dispersion in PVC paste is measured.
Thus, the foam cells can be made dense. Ma
Use surface-treated inorganic filler with high specific surface area
This allows a large amount of plasticizer to be added without any problem,
By increasing the flexibility of the foamed PVC,
It is possible to improve the shock absorbing property at the time of stone splash. What
Note that metal soap or the like may be used as the surface treatment agent.
It can be used in an amount of 0.5 to 5 with respect to the inorganic filler.
% By weight, particularly preferably 1 to 4% by weight. The amount of the filler is 100 parts by weight of the above PVC.
Preferably, it is 160 to 500 parts. 160 parts
If the amount is less, the flow during spray coating and the discharge property will be poor
If there is a possibility that more than 500 parts,
Physical performance may be degraded and elasticity may be reduced. In the present invention, a good plasticizer is used.
It is preferable to use an aromatic plasticizer. Such a good
As an aromatic plasticizer, dibutyl phthalate (DB
P), dihexyl phthalate (DHP), di-2-ethyl
Lehexyl phthalate (DOP), di-n-octylph
Tallate (DnOP), diisooctyl phthalate (D
IOP), didecyl phthalate (DDP), dinonylph
Tallate (DNP), diisononyl phthalate (DIN
P), diisodecyl phthalate (DIDP), C ₆ ~ C
_Ten Mixed higher alcohol phthalate, butyl benzyl cover
Rate (BBP), octylbenzyl phthalate, noni
Lebenzyl phthalate, butyl phthal butyl glycol
Esters (BPBG) and other phthalic acid esters,
Zyl phosphate (TCP), trixylenyl phosphate
(TXP), monooctyl diphenyl phosphate
G, monobutyl-dixylenyl phosphate (BZ-
X) etc., phosphates such as dipropylene glycol
Nzoate, N-butyl benzoate, 2,2,4-to
Limethyl-1,3-pentanediol isobutyrate
Nzoate, 2,2,4-trimethyl-1,3-pentane
Benzoic acid esters such as
Examples of phenolic alkyl sulfonic esters
Can be used alone or in combination of two or more.
Phthalic acid
Stels, especially dialkyl phthalate, alkyl benzyl
Luphthalate and benzoate are preferably used.
You. Also, other plasticizers such as dioctylazi
Pate (DOA), dioctyl azelate (DOZ),
Linear dibasic acids such as dioctyl sebacate (DOS)
Phosphorus such as ters and trioctyl phosphate (TOF)
Acid ester, 2,2,4-trimethyl-1,3-pentane
Diol mono- or diisobutyrate, tributyl
Enoic acid ester, trioctyl acetyl citrate S
Tell, C ₆ ~ C _Ten Fatty acid tri- or tetraethylene glycol
The above, such as coal ester and methyl acetyl ricinolate
Other than ester plasticizer, nitrile synthetic rubber, chlorinated
Products and petroleum auxiliary plasticizers, or a mixture of these
Etc. can also be used. In the present invention, the spray workability is improved.
A low boiling point plasticizer having a boiling point of 150 to 250 ° C.
For example, petroleum hydrocarbons (paraffinic, naphthenic,
It is preferable to add an (aromatic) plasticizer or the like. That arrangement
The combined amount is 5 to 50 parts per 100 parts of PVC, more preferable.
5 to 40 parts, more preferably 10 to 30 parts.
Is preferred. If more than 50 parts, low boiling plasticizer at baking
Volatilizes, lowers the expansion ratio, and cracks and abnormal
Foam may be generated. Including the above-mentioned aromatic plasticizer and low-boiling plasticizer
Total plasticizer amount is 180 to 100 parts of PVC.
500 parts, preferably 180 to 300
Part. If less than 180 parts, PV
The gelation rate of C sol is increased, which hinders the formation of foam cells.
In addition to lowering the expansion ratio, the hardness of the coating film after baking
Also becomes harder, and the shock absorption of foamed PVC decreases, resulting in soundproofing.
Performance may be reduced. On the other hand, more than 500
The physical properties of the coated film after baking are too soft,
In some cases, it is not possible to secure the security. The undercoat agent of the present invention contains an adhesive component
Polyamide amine and blocked isocyanate
Can be used alone or in combination to form a foamed PVC coating
It is preferable from the viewpoint of improving the adhesion to the material.
Combined use of liamidoamine and blocked isocyanate
And water and corrosion resistance are remarkably improved.
Stability is also significantly improved. This is with polyamidoamine
Urethane bond is formed by crosslinking with blocked isocyanate
Flexibility and elasticity are imparted to the PVC coating, which absorbs shock
Performance is improved, and excellent effects in sound evaluation are given.
Conceivable. The amount is 5 to 100 parts of PVC.
It is preferably 40 parts, particularly preferably 10 to 30 parts.
In this case, the polyamidoamine is 0 to 100 parts of PVC.
30 parts, especially 5 to 20 parts, the blocked isocyanate is P
1 to 35 parts, especially 3 to 25 parts per 100 parts of VC
Preferably. Less than 5 parts of the adhesion component
If not, the effect will not be sufficiently exhibited.
C sol has increased liquid viscosity and reduced spray workability.
There is it. Further, the undercoat agent of the present invention contains an acid
Calcium fluoride, magnesium oxide, etc. in the sol
Prevents foaming due to moisture by catching moisture
PVC100 from the viewpoint of improving the water resistance and corrosion resistance of C
5 to 100 parts, especially 10 to 40 parts per part
Can be. The addition of the desiccant is particularly effective during the process.
This is preferable because the problem of blistering does not occur. Immediately
For example, the line stops on Saturdays and holidays,
The undercoat agent before foaming
If there is a risk of blistering due to moisture absorption,
The addition of this hygroscopic agent is preferred. Further, dibutyltin laurate type, zinc type
PVC as an air conditioner using a PVC stabilizer such as an organic composite agent
0 to 5 parts, especially 0.1 to 3 parts is mixed with 100 parts.
be able to. In addition, as a colorant, carbon black
, Titanium oxide, cadmium yellow, phthalocyanine
Pigments such as blue can be used, and 100 parts of PVC
0 to 5 parts, preferably 1 to 3 parts can be compounded.
You. The undercoat agent of the present invention is particularly useful for automobiles.
Under the floor of the floor or the panel of the wheel house
Suitable for coating, the undercoat agent of the present invention
To the floor of the car floor or the panel of the wheel house
When forming an undercoat film, use this undercoat
After the agent is spray applied to the panel,
C. to form a foamed PVC layer. this
In this case, the thickness of the foamed PVC layer (film) is 1 to 4 mm,
Preferably 1.5 to 4 mm, more preferably 2 to 4 mm
It is preferred to do so. If it is thinner than 1mm, chipping resistance
Of soundproofing performance due to deterioration of shock absorption and shock absorption
There is a possibility of. On the other hand, if the thickness is more than 4 mm, the
And the weight of the vehicle increases, the coating workability decreases, and the vertical
This is a concern. According to the present invention, the use of non-foamed PVC
In general, a film with a thickness of 6 mm or more
It is necessary to have a thick undercoat film.
Even so, a sufficient noise prevention effect is exhibited. Heating, foaming, and curing are performed in the coating of automobiles.
Drying and baking of middle coat and top coat in the process
It is recommended to do this at the same time. As an undercoat method, a panel
Seal blowing at the joints for waterproofing and dustproofing
For rust prevention and chipping resistance on coating and general panel surfaces
Surface spraying, which is usually performed first.
Spray coating is performed, and surface spray coating is performed from above
You. Therefore, since both are applied in an overlapping manner, the dryness of both layers is
Requires compatibility before drying (at the time of application) and adhesion after drying
Therefore, the method used for seal spray coating and face spray coating
Undercoating agents are preferably of the same type
However, the undercoating agent of the present invention is
Can be applied to both storage tanks, piping,
Excellent in equipment and workability such as coating equipment
It is. It should be noted that the undercoat agent of the present invention is sprayed with a seal.
If the seal is used for both
The surface is sprayed in the
Preferably. Also used only for face spray application
If the undercoat agent of the present invention is PVC-based
As an undercoat agent for seal spray application
Use a PVC material for compatibility and adhesion
Is preferred. The undercoat agent of the present invention has a two-layer structure.
In the undercoat film, the lower cushioning material
How to configure or use as a surface layer (upper layer)
Method, and also apply to two-layer type such as use for both upper and lower layers
Although it is possible to use a single-layer type,
You. The undercoat agent of the present invention was made into a single layer.
Excellent chipping resistance and noise prevention effect even in cases
As described above, even if the undercoat film is thin, this effect
Advantages of single-layer workability
Can be enjoyed enough. The present invention will now be described specifically with reference to Examples and Comparative Examples.
However, the present invention is not limited to the following examples.
Not. In the following examples, each performance test
The method is as follows. In the following example,
“G” means a coating film in a gel state before foaming and curing. [Test Method] Chipping resistance A wet film thickness of 1 m on a steel plate coated with electrodeposition
m and baked at 130 ° C. for 20 minutes.
Set the sample above at an angle of 60 ° from horizontal with the painted surface up.
And placed vertically on this coating surface with an inner diameter of 20 mm
Touch the lower end of a 2m PVC pipe, and
M-4 nut specified in JIS through the pipe from the end
The nut until the base is exposed.
It was measured. [0043] Adhesion Apply sample 1mm wet on steel plate with electrodeposition coating
And baked at 130 ° C. for 20 minutes. Cutter for printing sample
Make a cut with a knife, peel off from the end with a nail,
The quality of adhesion was determined by the degree of peeling. ：: cohesive failure Δ: mixture of cohesive / interfacial fracture ×: interfacial fracture [0044] Stone splash sound reduction effect 1.6x300x300mm central part on electrodeposited steel plate
Form a coating film of specified thickness with an area of 190 x 190 mm
Then, the steel sheet is externally dimensioned to 300 x 300 mm and internal dimension to 20 mm.
0x200mm, sandwiched by a 20mm thick steel square frame,
The frame 1 is arranged at an angle of 45 ° as shown in FIGS.
And a salt having an inner diameter of 25 mm and a length of 2 m above the coating film 2.
Put the vinyl resin pipe 3 in the center of the coating 2
Position it so that it falls. And 8mm in diameter, heavy
2.08g steel balls one by one from pipe 3
When dropped and a steel ball collides with the coating film 2
Measure the impact sound generated at the time. In this case, under pipe 3
The end position is 40mm above the center of the coating 2, and the impact sound
Microphone 4 is 20 cm from the center of the coating film 2.
0 mm above, at a position 40 mm away from pipe 3
installed. The results are average values of eight measurements. In this case, a steel sheet having no coating film is formed.
The impact sound of POA value (2.5 to 10 KHz value) is 106
dB, and the result is how much
Was evaluated as having decreased. [0046] Spray workability Airless spray pump on steel plate with electrodeposition coating
(Compression ratio 45: 1) and 3/8 inch x 5m hose
Used, temperature 30 ° C, gun source static pressure 100kgf / c
m ^Two , Gun distance 300mm, tip # 443 (Japanese gray
Each sample is applied under the conditions of (I) and the pattern width is measured.
Then, the quality of spray workability was determined. ：: pattern width of 200 mm or more Δ: pattern width of 150 to 200 mm ×: 150 mm or less [Examples and Comparative Examples] PV of the formulation shown in Table 1
C sol is prepared and foamed at 130 ° C for 20 minutes.
Evaluation of chipping resistance, sound evaluation and adhesion by type
And the spray operability of PVC sol was evaluated.
Was. The results are shown in the same table. [Table 1] * 1 Paste PVC: Paste polyvinyl chloride, average weight
1200 degree, average particle size 1μm or less (The particle size distribution
Peak having a peak: primary particle diameter 0.1 μm, secondary particle diameter 12 μm) [E-7031 (trade name) manufactured by Huls (Germany)] * 2 Paste PVC: paste polyvinyl chloride, average weight
1600, average particle size 2μm (particle size distribution is one peak
* 3 Paste PVC: Paste polyvinyl chloride, average weight
2000, average particle size 1μm (particle size distribution is one peak
* 4 Paste PVC: Paste polyvinyl chloride, average weight
1000, average particle size 20 μm (particle size distribution is
* 5 Copolymer resin: vinyl chloride / vinyl acetate copoly
(Vinyl acetate content 8% by weight), average degree of polymerization 190
0, average particle size 1 μm or less (The particle size distribution has two peaks.
Peak: 1 μm primary particle size, 10 μm secondary particle size) * 6 Copolymer resin: vinyl chloride / vinyl acetate copoly
(Vinyl acetate content 5% by weight), average polymerization degree 160
0, average particle size 2 μm (particle size distribution has one peak
* 7 Copolymer resin: vinyl chloride / vinyl acetate copoly
(Vinyl acetate content 11% by weight), average degree of polymerization 100
0, average particle size 20 μm (particle size distribution has one peak
* 8 Low boiling plasticizer: paraffinic hydrocarbon, boiling point 170
° C. From the results shown in Table 1, primary particles and secondary particles were mixed.
When using existing vinyl chloride resin, chipping resistance
With excellent characteristics, good sound evaluation and adhesion,
It is recognized that the spray workability is excellent. The undercoat agent for noise prevention of the present invention
Has good spray workability and excellent chipping resistance
Gives a coating film that has good properties and adhesion, and is excellent in noise prevention.
Things.

[Brief description of the drawings] FIG. 1 is a side view of an apparatus for measuring the effect of reducing rock flies. FIG. 2 is a front view of the rock popping noise reduction effect measuring device. [Explanation of symbols] 1 frame 2 Coating 3 pipe 4 microphones

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsutomu Ochi 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Yutaka Ohashi 1 Toyota Town Toyota City, Aichi Prefecture Toyota Motor Corporation ( 56) References JP-A-6-316664 (JP, A) JP-A-10-287825 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09D 127/06 B05D 5/00 C09D 5/00 B05D 7/24

Claims (1)

(57) [Claims 1] In a noise-preventing undercoating agent containing a vinyl chloride-based resin, an organic foaming agent, a plasticizer, and a filler, the vinyl chloride-based resin has an average particle size. 5 μm in diameter
An undercoat agent for noise prevention, comprising at least 50% by weight of vinyl chloride resin particles comprising the following primary particles and secondary particles having an aggregate of the primary particles and having an average particle size of 100 μm or less. .