JPH083072B2 - Vinyl chloride plastisol-based coating composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vinyl chloride plastisol-based paint, for example, an undercoat agent for automobiles. More specifically, it relates to an undercoat agent for automobiles which uses a safe dispersant which is odorless and does not contain aromatic hydrocarbons and therefore does not pollute the working environment.

[Prior Art and its Problems] In recent years, the underfloor, side seals, fuel tanks, front aprons, and tire house parts of automobiles have been protected from damage caused by flying stones instead of conventional asphalt undercoat agents. For this reason, a coating agent called a vinyl chloride plastisol-based anti-pitting agent is generally applied by an airless coating device.

The basic formulation of this anti-pitting agent is to prevent damage to the coating film by incorporating a large amount of inorganic or organic filler and applying it thickly.

However, although a certain degree of viscosity is required to enable thick coating, the viscosity tends to be too high due to the incorporation of a large amount of filler.

Conventionally, petroleum fractions such as kerosene and light oil have been used as a dispersant in order to adjust the viscosity to an appropriate level so that it can be applied. However, in the case of kerosene, there is a phenomenon that the viscosity of vinyl chloride plastisol is increased and the viscosity is increased. Further, kerosene as a dispersant is released into the atmosphere in the drying step after coating,
These kerosene oils are not necessarily odorless, and since they contain aromatic hydrocarbons at a considerably high concentration, there are concerns about environmental pollution and safety for the human body.

[Problems to be Solved by the Invention] The present invention aims to develop a vinyl chloride plastisol-based coating composition using a dispersant that does not cause gelation of vinyl chloride plastisol and is odorless and does not cause environmental pollution. To do.

[Means for Solving the Problems] A first object of the present invention is to use a kerosene fraction having a boiling point of 150 to 300 ° C. as a dispersant in a vinyl chloride plastisol-based coating material by using a metal catalyst for nuclear hydrogenation of an aromatic nucleus. Pressure 10 to 10
Nuclear hydrogenation treatment under the conditions of 0 kg / cm ² and a temperature of 100 to 300 ° C., and then using a molecular sieve composed of synthetic zeolite to separate at least a part of n-paraffins in the kerosene fraction,
The residual oil obtained by removal is fractionated by a precision distillation apparatus, and a hydrocarbon mixture fraction having a boiling point range of 150 to 300 ° C substantially free of naphthalene and biphenyl is used. This is achieved by providing the vinyl chloride plastisol-based coating composition of the invention.

A second object of the present invention is to use a kerosene fraction having a boiling point of 150 to 300 ° C. as a dispersant in a vinyl chloride plastisol-based coating material by a metal catalyst for nuclear hydrogenation of aromatic nuclei at a pressure of 10 to 10 ° C.
First stage nuclear hydrogenation treatment under the conditions of 0 kg / cm ² and temperature of 100 to 300 ° C., and then using a molecular sieve made of synthetic zeolite, at least a part of n-paraffins in the kerosene fraction is separated and removed. If necessary, the residual oil obtained by distilling is fractionally distilled by a precision distillation apparatus, and then the second stage hydrogenation treatment is performed under conditions that are substantially the same as or milder than those of the first stage, and then precision distilled. It is achieved by providing a vinyl chloride plastisol-based coating composition of the present invention, which comprises using a hydrocarbon mixture having a boiling point of 150 to 300 ° C. substantially free of aromatic hydrocarbons.

[Operation] Vinyl chloride plastisol is a composition prepared by dispersing a vinyl chloride resin in a plasticizer and adding additives such as a filler and a dispersant thereto.

The vinyl chloride resin for plastisols has a relatively low molecular weight, for example, a degree of polymerization of about 500 to 5000, polyvinyl chloride, homopolymers such as polyvinylidene chloride, vinyl chloride, vinylidene chloride, vinyl acetate, etc. The copolymers of These may be used alone or as a mixture of two or more.

Examples of plasticizers include dioctyl phthalate (DOP) and dinonyl phthalate; phthalic acid esters such as octyl adipate and dioctyl azelate; phosphoric acid esters such as diphenyloctyl phosphate;
Hydroxypolycarboxylic acid ester such as acetyl tributyl citrate; fatty acid ester such as palmitate, butyl stearate and hydrogenated rosin methyl ester; epoxy plasticizer such as epoxidized soybean oil and epoxidized castor oil; poly (propylene) Examples thereof include polyester plasticizers such as glycol and adipic acid) esters.

Particularly, phthalic acid plasticizers such as DOP are suitable from the viewpoints of economy and performance.

As the filler, talc, calcium carbonate, diatomaceous earth,
Mica, kaolin, barium sulfate, magnesium carbonate,
Inorganic fillers such as airisil, vermiculite, graphite, alumina, silica, glass balloons, shirasu balloons, silica balloons; thermosetting or thermoplastic resin powders, organic fillers such as thermoplastic resin hollow bodies such as polyethylene, etc. It can be illustrated.

The plasticizer and the filler are, based on 100 parts by weight of the vinyl chloride resin, about 50 to 200 parts by weight, preferably 60 to 180 parts by weight, 50 to 300 parts by weight of the filler, preferably 60 to 250 parts by weight. It is compounded in the range.

In the present invention, a kerosene fraction having a boiling point of 150 to 300 ° C. is hydrogenated by a metal catalyst for nuclear hydrogenation of aromatic nuclei. Any conventionally known metal catalyst for hydrogenating an aromatic nucleus can be preferably used as this catalyst.

For example, nickel, nickel oxide, nickel / diatomaceous earth, Raney-nickel, nickel / copper, platinum, platinum oxide,
Platinum / activated carbon, platinum / rhodium, platinum / lithium / alumina, rhodium / activated carbon, palladium, cobalt, Raney-cobalt, ruthenium, nickel / tungsten, tungsten sulfide / nickel sulfide / alumina, cobalt /
Molybdenum and the like can be preferably used.

The hydrogen pressure is 10 to 100 kg / cm ² , and the temperature is 100 to 300 ° C. The hydrogenation reaction does not proceed sufficiently at a pressure lower than 10 kg / cm ² or a temperature lower than 100 ° C, and a side reaction such as decomposition takes precedence at a pressure higher than 100 kg / cm ² or a temperature higher than 300 ° C. Absent. As the reaction system, any method such as a batch system or a continuous / flow system can be adopted.

Here, the aromatic hydrocarbons in kerosene are nuclear hydrogenated to naphthenes by the above hydrogenation, but usually 100% of the aromatic hydrocarbons contained are not nuclear hydrogenated and the above-mentioned catalyst A certain amount of aromatic hydrocarbons remain without being hydrogenated depending on the type and reaction conditions. Further, the hydrogenation treatment is often accompanied by an isomerization reaction as a side reaction, and products related to these reactions are inevitably contained in the hydrogenated kerosene fraction.

Then, the kerosene fraction is separated and removed at least a part of the n-paraffins in the kerosene fraction using a molecular sieve made of synthetic zeolite to obtain a residual oil.

A method of separating and obtaining n-paraffins from a hydrocarbon mixture by repeating adsorption / desorption in a gas phase or a liquid phase using a molecular sieve has hitherto been industrially used as a method for producing n-paraffins as follows. Widely implemented.

That is, for example, a molecular sieve made of synthetic zeolite having a large number of pores adjusted to 5 A (angstrom) is used as a fixed bed, and adsorption / desorption of n-paraffins are alternately performed in a liquid phase to adsorb n-paraffins. Is washed with desorption low molecular weight paraffin to desorb the n-paraffins, and the mixed desorption low molecular weight paraffin is separated by distillation and recirculated, and the Molex method is used, and a large number of holes adjusted to 5A (angstrom) are also used. N-in the gas phase using adsorption and desorption by a molecular sieve composed of synthetic zeolite
TSF method (Texaco Selective Finishing method) in which paraffins are adsorbed and desorbed with low molecular weight paraffin, and a molecular sieve made of 5A zeolite is also used, but n-paraffins are adsorbed and desorbed on the molecular sieve under pressure.・ The iso-sieving method, which is performed by alternately repeating depressurization, and the method combining the vapor phase and liquid bed methods,
Adsorption of paraffins to a molecular sieve composed of synthetic zeolite having 5A pores is carried out continuously in a liquid bed in an adsorption device,
The desorption is operated in the regenerator at a temperature higher than the adsorption, and the regenerated molecular sieve is returned from the regenerator to the adsorber and recirculated to the esso method.

The n-paraffins can be separated by any method using a molecular sieve composed of these synthetic zeolites having pores of 5A.

Generally, in separating n-paraffins, theoretically only n-paraffins should be separated. However, depending on the method, hydrocarbons other than n-paraffins may be n.
-The content of components other than n-paraffins in the residual oil obtained as a result of separation accompanying the paraffins may change. Considering this point, there is a method of industrially separating n-paraffins by using urea crystals, but as the method of the present invention, a molecular sieve made of synthetic zeolite having pores of 5A is used. Various methods are suitable.

The n-paraffins are separated from the kerosene fraction treated with hydrogen as described above to obtain a residual oil. Next, the residual oil is precision distilled. For this purpose, for example, a precision distillation apparatus consisting of two or more distillation columns is used, light hydrocarbons are removed from the top of the first column, and the target fraction is produced from the second column or the subsequent columns. To be done. As a matter of course, if the separation efficiency such as the number of distillation stages is appropriate, light hydrocarbons and heavy hydrocarbons are removed from the top and bottom of a precision distillation apparatus consisting of one distillation tower, respectively, and the objective from the center of the tower. It is also possible to produce a distillate. The precision distillation may be performed after the second-stage nuclear hydrogenation described below.

With the above precision distillation device, the boiling point is 150 to 300 ° C, preferably
A hydrocarbon mixture in the range of 200-280 ° C is obtained.

It is necessary that the boiling point of the hydrocarbon mixture fraction of the present invention is within the above range, and if it is out of this range, the existence of each component and the balance of the contents are lost, and the intended purpose cannot be achieved. That is, in a range lower than the above boiling point range, a large amount of harmful aromatic hydrocarbons such as benzene and toluene are contained, which is not preferable. Further, if it exceeds 300 ° C., the boiling point is too high, the drying property after coating is poor, and the drying property is lowered, so that the residual odor becomes strong, which is not preferable.

The above hydrocarbon fraction does not substantially contain benzene, toluene, etc., and has a small content of other aromatic hydrocarbons, and particularly does not contain naphthalene and biphenyls. However, in the present invention, for the purpose of higher safety, for example, to eliminate substantially all kinds of aromatic hydrocarbons, the residual oil is subjected to a second stage hydrogenation treatment. It is also possible to obtain a distillate containing substantially no aromatic hydrocarbon.

Here, the second stage hydrogenation to the residual oil can be performed in the same manner as the first stage nuclear hydrogenation. Alternatively, nuclear hydrogenation may be performed under milder conditions, ie, lower temperature or lower pressure. The nuclear hydrogenation metal catalyst used in the second stage does not necessarily have to be the same as in the first stage. That is, the catalyst may be the same or different. In any case, it may be appropriately selected from the above hydrogenation conditions.

Next, after the second-stage nuclear hydrogenation, precision distillation is carried out as necessary as described above.

With the above precision distillation device, the boiling point is 150 to 300 ° C, preferably
A hydrocarbon mixture fraction in the range 180 to 280 ° C is obtained.

The dispersant of the present invention comprises the fraction obtained as described above, and the fraction is a hydrocarbon fraction having a low aromatic hydrocarbon content or substantially no aromatic hydrocarbon.

The amount of the dispersant of the present invention is not particularly limited because it is appropriately used for viscosity adjustment, but is usually 1 to 30 parts by weight, preferably 2 to 100 parts by weight of the vinyl chloride resin. 20 parts by weight. When the compounding amount is less than this range, the effect of decreasing the viscosity is small, and even when the compounding amount exceeds this range, the effect commensurate with it is not obtained, which is not economically preferable.

In the present invention, a tackifying resin is added to improve the adhesion to the coated surface. This tackifying resin is an aromatic, alicyclic or aliphatic petroleum resin, rosin,
Examples thereof include Rodinester and terpene resin. These amounts are appropriately determined, but usually vinyl chloride resin 100
The amount is 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight.

In addition, colorants such as carbon black, pigments,
Dyes, stabilizers, foaming agents, antioxidants, preservatives, thixotropic agents,
Anti-freezing agents, pH adjusters and the like can be added.

The paint of the present invention can be applied by brush coating or the like, but since the viscosity can be adjusted appropriately, it is preferably applied by spraying, for example, by an airless coating device.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples.

Dispersant Production Example-1 A kerosene fraction having a boiling point range of 150 to 300 ° C (65% by weight of paraffins, 25% by weight of naphthenes, 10% by weight of aromatics) obtained by distilling crude oil was added at 280 ° C and 90 kg / cm ² Under the conditions described above, using a Ni-W catalyst for nuclear hydrogenation of aromatic hydrocarbons as a catalyst, nuclear hydrogenation was carried out, and the resulting product was obtained by the Molex method using a molecular sieve having 5A pores composed of synthetic zeolite. Was supplied to a separation column filled with to separate n-paraffins.
The residual oil fraction depleted in n-paraffins is then precision distilled using two columns of precision distillation equipment to obtain a boiling point of 205-235.
A hydrocarbon mixture fraction at ° C was obtained. The composition and properties of this dispersant are shown in Table 1.

Dispersant Production Example-2 The residual oil fraction reduced in n-paraffins obtained in the step of Dispersant Production Example-1 above was used as a catalyst under conditions of 200 ° C. and 50 kg / cm ^2. Then, the product obtained by the second stage hydrogenation treatment was subjected to precision distillation using a two-column precision distillation apparatus to obtain a hydrocarbon mixture fraction having a boiling point of 203 to 233 ° C. The composition and properties of this dispersant are also shown in Table 1.

Example A chipping-resistant paint of vinyl chloride sol was blended according to the following formulation.

Polyvinyl chloride resin (blend of polyvinyl chloride resin and vinyl chloride / vinyl acetate copolymer resin) 100 parts by weight DOP 120 parts by weight Calcium carbonate 150 parts by weight Aromatic petroleum resin (softening point 120 ° C) 1 part by weight Dispersant 10 Parts by weight Using the dispersants of Dispersant Production Examples 1 and 2 as Examples, a sol having an extremely good viscosity was obtained and coating was possible with an airless coating apparatus, but as a comparative example, kerosene (boiling point 200 to The sol with 280 ° C) as a dispersant gelated and could not be coated with an airless coating device.

Next, an amount such that the thickness of the film when dried was 850 μm was applied to the test panel, dried and the dispersant was volatilized, and the odor at that time was judged by 5 male and 5 female panelists.

The criteria for odor are as follows: extremely strong solvent odor; 5, strong solvent odor; 4, weak solvent odor; 3, almost no odor; 2, no odor; 1 It was

In Dispersant Production Examples 1 and 2 as Examples, the odor had a numerical value of 2 and the kerosene as a Comparative Example had a numerical value of 4.

[Effects of the Invention] The vinyl chloride plastisol-based coating material of the present invention has a suitable viscosity without gelling because the dispersant used therein has an appropriate solubility with the vinyl chloride resin. Because it can be done, painting work is easy.

Since conventional petroleum-based solvents contain a considerable amount of xylene and other aromatic components in their components, they are highly toxic to the human body and their adverse effects on the human body are regarded as important and pose a problem. In particular, in the Ministry of Labor ordinance's Ordinance for Prevention of Disorders of Specific Chemical Substances, the benzene content exceeds 1% by volume, and in the Ordinance for Prevention of Organic Agent Poisoning in the same Ordinance, the total of toluene and xylene exceeds 5% by weight. The handling of each is severely limited. Regarding naphthalene, biphenyls, etc., OSHA (Occupational Safety and Health A
Dministration) enacted "Standards for public awareness of hazards of chemical substances" are subject to regulation, and products containing these compounds are obliged to label these compounds.

However, the dispersant according to the present invention satisfies all of the above criteria and has a low aromatic hydrocarbon content, so it is safe in operation and does not pollute the environment. Furthermore, since it is odorless, it has the feature that the drying process can be performed with peace of mind. Therefore, it is most suitable as an undercoat agent for coats such as automobile bedding.

Claims (2)

[Claims] 1. A vinyl chloride plastisol-based paint,
As a dispersant, kerosene fraction in the boiling point range of 150 ~ 300 ℃,
Pressure 10 to 100 kg / with a metal catalyst for nuclear hydrogenation of aromatic nuclei
It is obtained by nuclear hydrogenation treatment under the conditions of cm ² and temperature of 100 to 300 ° C., and then separating and removing at least a part of n-paraffins in the kerosene fraction using a molecular sieve made of synthetic zeolite. A vinyl chloride plastisol-based coating composition characterized by using a hydrocarbon mixture fraction having a boiling point of 150 to 300 ° C., which is substantially free of naphthalene and biphenyl, obtained by fractionating the residual oil by a precision distillation apparatus. Stuff. 2. A vinyl chloride plastisol-based coating material,
As a dispersant, kerosene fraction in the boiling point range of 150 ~ 300 ℃,
Pressure 10 to 100 kg / with a metal catalyst for nuclear hydrogenation of aromatic nuclei
First stage nuclear hydrogenation treatment under conditions of cm ² and temperature of 100 to 300 ° C., and then using a molecular sieve made of synthetic zeolite, at least a part of n-paraffins in the kerosene fraction is separated and removed. If necessary, the residual oil obtained is fractionally distilled by a precision distillation apparatus, and further subjected to a hydrogenation treatment of the second stage under the conditions substantially the same as or milder than the first stage,
A vinyl chloride plastisol-based coating composition characterized by using a hydrocarbon mixture fraction having a boiling point of 150 to 300 ° C., which is obtained by precision distillation of this and is substantially free of aromatic hydrocarbons.