JPH0859938A - Plastisol composition - Google Patents

Abstract

PURPOSE: To obtain a plastisol composition capable of providing a good coated appearance without forming any irregularity and not repelling paints for an internal coating and a top coating in using as a body sealer and a chipping resistant agent for automobiles. CONSTITUTION: This plastisol composition is obtained by blending a vinyl chloride-based resin for a paste, 30-400 pts.wt. plasticizer and 30-300 pts.wt. filler, based on 100 pts.wt. resin, and by using as the plasticizer a polyester-based plasticizer comprising the structure of a polycondensation product of a dibasic acid with a dihydric alcohol having >=50mol% content of 3-methyl-1,5-pentanediol residue in the dihydric alcohol component.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to plastisol compositions. More specifically, it relates to a plastisol composition based on a vinyl chloride resin, which is suitable for body sealers for vehicles such as automobiles and for chipping-resistant agents.

[0002]

2. Description of the Related Art Seams and joints of steel plate members of vehicles such as automobiles are coated or filled with a sealing agent usually called a body sealer, and an intermediate coating material and a top coating material are applied thereon. Also, in order to prevent damage to the coating film caused by pebbles, gravel, etc. on the road surface while the vehicle is running and the resulting rusting and corrosion of the base member, electrodeposition on the side and bottom surfaces of the vehicle body In many cases, an anti-chipping agent is applied to the painted surface, and then an intermediate coating material and a top coating material are applied thereon.

Examples of such body sealers and anti-chipping agents include vinyl chloride resins for pastes (paste resins), plasticizers and fillers such as phthalic acid diesters such as di-2-ethylhexyl phthalate (DOP), and fillers. In many cases, a plastisol composition containing a stabilizer or the like was used. However, when a plastisol composition using a general plasticizer is used for the above-mentioned applications, when the coating material is applied over it, the plasticizer migrates into the coating material and the coating surface becomes sticky or the coating material is repelled. However, it often causes problems such as uneven coating, and it has been difficult to obtain a good coating appearance.

Polyester plasticizers have been used to solve these problems, but although they are improved compared to phthalic acid diesters, a sufficiently satisfactory coating appearance has not yet been obtained.

[0005]

DISCLOSURE OF THE INVENTION The inventor of the present invention has conducted extensive studies to obtain a plastisol composition which can give a good coating appearance when used as a body sealer or a chipping-resistant agent, and based on this plastisol composition In addition to the generally known improving means of reducing the migration of plasticizer into the coating material overlaid on the coating film, to reduce the compatibility between the plasticizer in the plastisol composition and the resin in the coating material. Has been found to have a remarkable effect on the improvement of the coating appearance, and completed the present invention.

[0006] That is, an object of the present invention is to obtain a vinyl chloride-based plastisol composition which gives a good coating appearance when used as a body sealer or a chipping-resistant agent.

[0007]

The gist of the present invention is as follows. First, a vinyl chloride resin for paste and the resin 1
30 to 400 parts by weight of plasticizer per 30 parts by weight and 30 to
A plastisol composition containing 300 parts by weight of a filler, which is a polyester obtained by polycondensing a dibasic acid and a dihydric alcohol as a plasticizer, and in a dihydric alcohol residue of the polyester. 3-methyl-
A plastisol composition comprising a polyester-based plasticizer having a proportion of 1,5-pentanediol residues of 50 mol% or more, and secondly, An automotive body sealer or a chipping-resistant agent comprising a plastisol composition.

Hereinafter, the present invention will be described in detail. The vinyl chloride resin for paste, which is the resin component of the plastisol composition of the present invention, is usually produced by an emulsion polymerization method or a fine suspension polymerization method. The emulsion polymerization method includes, for example, vinyl chloride alone or a mixture of vinyl chloride and a comonomer copolymerizable therewith (hereinafter, abbreviated as “vinyl chloride-based monomer”), sodium lauryl sulfate and dodecylbenzenesulfonic acid. This is a method of radical polymerization in the presence of an emulsifier such as sodium and a water-soluble polymerization initiator.

The fine suspension polymerization method is a method in which a vinyl chloride monomer is homogenized with a disperser such as a homogenizer together with an emulsifier and / or a dispersant and a polymerization initiator soluble in vinyl chloride, and then polymerized. is there. Examples of the above-mentioned comonomer copolymerizable with vinyl chloride include vinyl acetates such as vinyl acetate, vinyl propionate and vinyl benzoate, and (meth) acrylic acid such as methyl (meth) acrylate and ethyl (meth) acrylate. Examples thereof include esters, unsaturated dibasic acid diesters such as dimethyl maleate, diethyl maleate and dimethyl fumarate, vinyl ethers such as methyl vinyl ether and isobutyl vinyl ether, unsaturated nitriles such as acrylonitrile, and vinylidene chloride.

The plastisol composition of the present invention contains 30 to 400 parts by weight of vinyl chloride resin for paste.
Parts by weight, preferably 50 to 200 parts by weight, of plasticizer are used. The plasticizer is a polyester obtained by polycondensing a dibasic acid and a dihydric alcohol,
And the proportion of 3-methyl-1,5-pentanediol residues in the dihydric alcohol residues of the polyester is 50 mol%
As described above, a polyester-based plasticizer composed of 70 mol% or more is preferably used.

The proportion of 3-methyl-1,5-pentanediol residues contained in the dihydric alcohol residue of this polyester can be measured by gas chromatographic analysis of the hydrolysis product of the polyester. .
As the dibasic acid component of the polyester plasticizer, those having 2 to 10 carbon atoms are preferable, and succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, phthalic acid and the like can be exemplified, but they are economical. From the viewpoint of performance, it is preferable to use adipic acid.

Further, as the dihydric alcohol component, one having a composition such that the content of 3-methyl-1,5-pentanediol residue in the produced polyester is 50 mol% or more is used. Here, as the dihydric alcohol that can be used together with 3-methyl-1,5-pentanediol, those having 2 to 9 carbon atoms are preferable from the viewpoint of compatibility with the vinyl chloride resin of the produced polyester. Ethylene glycol, diethylene glycol, 1,2-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, neopentyl glycol, 1,5-pentanediol, 1,6-
Examples include hexanediol and 1,9-nonanediol.

A monohydric alcohol or a monobasic acid is used to block the ends of the polyester. As the end-blocking agent, a monohydric alcohol having 4 to 13 carbon atoms or a monobasic acid having 4 to 12 carbon atoms is used. Is preferably used from the viewpoint of compatibility of the produced polyester with the vinyl chloride resin. Such monohydric alcohols include butanol,
Pentanol, hexanol, heptanol, n-octanol, 2-ethylhexanol, nonanol, decanol, undecanol, dodecanol, tridecanol and the like can be mentioned.

Examples of the monobasic acid include butyric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid and lauric acid. The viscosity of the polyester-based plasticizer is 100 to 3000 centipoise (0.1 to 3 Pa · s) at 25 ° C., preferably 150 to 150.
It is preferably 0 centipoise (0.15 to 1.5 Pa · s). This viscosity is related to the molecular weight of polyester, but if the viscosity is too low, the non-migration property is insufficient,
If the effect of improving the coating surface is small and the viscosity is too high, the fluidity of the plastisol composition may be adversely affected. The viscosity of the polyester can be adjusted by the polycondensation conditions and the amount of the monovalent acid or alcohol used as the terminal blocking agent.

The polyester plasticizer used in the plastisol composition of the present invention can be produced, for example, by the following method. 50% by mol of 3-methyl-1,5-pentanediol
The dihydric alcohol contained above, a dibasic acid somewhat more than the equivalent of the dihydric alcohol, and three components of the monohydric alcohol slightly larger than the difference in the equivalents of the dihydric alcohol and the dibasic acid, 100 to 2 using an esterification catalyst such as tetraisopropyl titanate or dibutyltin oxide.
Polycondensation is carried out under reduced pressure at a temperature of 50 ° C. while removing water produced.

A dihydric alcohol containing 50 mol% or more of 3-methyl-1,5-pentanediol, a dibasic acid somewhat less than the equivalent amount of the dihydric alcohol, and the above dihydric alcohol and the dibasic acid. The three components of the monobasic acid, which are slightly smaller than the equivalent difference, are polycondensed in the same manner as above. It is not clear why the above specific polyester plasticizer does not adversely affect the coating appearance and shows a good coating surface, but it is related to the small interaction with coating materials such as intermediate coating and top coating. Conceivable.

That is, when coating is applied on a body sealer or a chipping-resistant agent containing a plasticizer, the plasticizer migrates into the solvent of the paint, and as a result, the surface tension and fluidity of the paint change. It is said that "repellency" of paints and uneven coating occur. For example, the improvement effect of using a polyester plasticizer in place of dialkyl phthalate is due to the difference in molecular weight between the two. It can be explained to some extent as being caused by the difference in ease of movement (mobility).

It goes without saying that the specific polyester plasticizer used in the plastisol composition of the present invention exhibits the above-mentioned non-migration property, but in addition to this, the compatibility with the resin of the paint is 3
-Since it becomes particularly small in a polyester-based plasticizer containing a structure derived from -methyl-1,5-pentanediol, a coating such as an intermediate coating or a top coating was repeatedly applied to a coating film based on a plastisol composition containing the same. Even if
It is considered that the influence on these paints is significantly reduced and the paint appearance is greatly improved.

The filler used in the plastisol composition of the present invention is not particularly limited as long as it is a filler generally used for vinyl chloride resins, but it is usually heavy or light calcium carbonate (surface treated product). , Untreated products),
Inorganic fillers such as inorganic fillers such as magnesium carbonate, barium sulfate, aluminum hydroxide, talc, clay, diatomaceous earth, kaolin and glass balloons, powder rubber, cellulose powder, various fibers, wood powder, etc. Agent,
Calcium carbonate is particularly preferable.

The amount of the filler used in the composition of the present invention is 30 to 300 parts by weight, preferably 50 to 250 parts by weight, based on 100 parts by weight of the vinyl chloride resin for paste. In the plastisol composition of the present invention,
In addition to the specific polyester plasticizer described above, other plasticizers may be used in combination for the purpose of adjusting the fluidity of the plastisol and the flexibility after molding. Even in this case, the content of the polyester plasticizer in the total plasticizer is 30% by weight or more, preferably 70% by weight.
The above is better.

The plasticizer that can be used in combination is not particularly limited as long as it is used as a plasticizer for vinyl chloride resins, and examples thereof include dibutyl phthalate, diheptyl phthalate, and di-2-ethylhexyl phthalate. Phthalic acid diesters such as diisodecyl phthalate and butylbenzyl phthalate, adipic acid diesters such as di-2-ethylhexyl adipate and diisononyl adipate, trimellitic acid triesters, phosphoric acid triesters,
Alternatively, an epoxy plasticizer or the like can be exemplified.

In addition to the above-mentioned essential components, the plastisol composition of the present invention contains various additives such as stabilizers, adhesion promoters, antioxidants, ultraviolet absorbers, flame retardants and colorants (pigments, dyes). Etc.), thickeners, diluents and the like can be added as necessary. Further, the plastisol composition of the present invention is prepared by stirring and mixing a predetermined amount of the above-mentioned paste vinyl chloride resin, plasticizer, filler and other additives with a mixer such as a dissolver, a mixer or a kneader. It can be manufactured.

[0023]

EXAMPLES Specific embodiments of the present invention will be described below with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the examples, "%" and "parts" represent "wt%" and "parts by weight", respectively, unless otherwise specified. (1) Preparation of polyester plasticizer <Polyester plasticizer A> Adipic acid 146 g (1 mol), 3-methyl-1,5-pentanediol 85 g
(0.72 mol), 2-ethylhexanol 100 g
(0.77 mol), and 0.1 g of tetraisopropyl titanate were charged into a flask having an internal volume of 1 liter equipped with a thermometer, a nitrogen introduction tube (also a decompression nozzle), a stirrer, a water divider, and a reflux condenser, and nitrogen was added. The mixture was heated under a stream of air with stirring, and while the produced water was removed to the outside of the system by a water separator, the reaction liquid temperature was raised to 210 ° C. to start the reaction. Subsequently, the temperature was kept at 210 ° C. until the water did not distill, and when the water did not distill, the system was depressurized to reflux the alcohol, and the water was further removed by a water divider. When the reaction was carried out for 5 hours, the pressure was reduced to 5 mmHg (7 hPa) to remove excess raw material, and a polyester plasticizer having a viscosity of 250 centipoise (25 ° C.) was obtained.

<Polyester Plasticizers B to F> Table 1 below
A polyester plasticizer was prepared in the same manner as described above except that the reaction was carried out with the charged amount. The viscosity of the obtained plasticizer is also shown in Table 1. (Polyester plasticizer A
Also described. The unit of viscosity in the table is centipoise (cP). )

[0025]

[Table 1] (2) Preparation of plastisol composition Using the following raw materials, the plasticizer in Table 2 and the prescribed ingredients were weighed according to the following ingredients, and a planetary mixer (Hobart Mixer N-50 type, The Hobart Manufactory) was used. # 1 speed (61
5 minutes at rpm), 15 at # 2 speed (125 rpm)
The mixture was stirred for a minute to prepare a plastisol composition.

[0026]

[Table 2] <Raw materials> Vinyl chloride resin for paste: Vinica paste P-5
00, manufactured by Mitsubishi Kasei Vinyl Co., Ltd. (vinyl chloride-vinyl acetate copolymer, vinyl acetate content 5%) Plasticizer: Polyester plasticizer A to F (prepared by the method (1) above) DOP ( Diasizer DOP, Mitsubishi Kasei Vinyl Co., Ltd.
Filler: Surface-treated calcium carbonate, Shirakaneka CCR (manufactured by Shiroishi Industry Co., Ltd.) Heavy calcium carbonate, Whiten B (manufactured by Shiraishi Calcium Co., Ltd.) Adhesiveness agent: Adestar # 762 (Mitsubishi Kasei Vinyl Co., Ltd.) Stabilizer: tribasic lead sulfate, TS-102 (manufactured by Shinagawa Kako Co., Ltd.) <Blending> Vinyl chloride resin for paste 100 parts by weight Plasticizer 100 Surface-treated calcium carbonate 50 Heavy calcium carbonate 150 Adhesiveness Additive 30 Stabilizer 5

(3) Evaluation Method of Appearance of Coating The obtained plastisol composition was evaluated for appearance of coating when an intermediate coating composition and a top coating composition were applied by the following two coating methods. Wet-on-dry (coating appearance a) After applying the plastisol composition on a glass plate in a thickness of about 1 mm, predrying at 100 ° C. for 10 minutes was added, and then an intermediate coating material (film thickness 20 μm), and then A top coating composition (film thickness 40 μm) is applied and dried at 140 ° C. for 30 minutes, and the appearance of the coating film is visually observed to judge the quality.

Wet-on-wet (coating appearance b) A coating film was prepared in the same manner as in the above method except that predrying after coating the plastisol composition was not carried out, and the appearance was observed and evaluated. The evaluation results are shown below.

[0029]

[Table 3] ◎: There is no unevenness or transparency of the coated surface ○: 〃 Almost no △: 〃 Some ×: 〃 Remarkable <Examples 1 to 4> Polyester plasticizer A prepared in (1) above D was used to prepare a plastisol according to the methods of (2) and (3) above, and the coating appearance of the obtained coating film was evaluated. The results are summarized in Table 2 below. <Comparative Examples 1 to 3> The above Examples except that polyester-based plasticizers E, F or DOP (di-2-ethylhexyl phthalate) not corresponding to the plasticizer component of the composition of the present invention were used as the plasticizer. A plastisol composition was prepared in the same manner as above, and the coating appearance was evaluated. The results are also shown in Table 2 below.

[0030]

[Table 4] * 1: Kind of plasticizer ... Corresponding to polyester plasticizers A to F shown in Table-1. (Excluding DOP) * 2: The content of 3-methyl-1,5-pentanediol residue does not correspond to the charging ratio because of the loss of dihydric alcohol during the reaction.

[0031]

As is clear from the results shown in Table 2, the plastisol composition of the present invention uses a specific polyester plasticizer which is difficult to migrate to the paint as the plasticizer and has low compatibility with the resin in the paint. Therefore, after applying the intermediate coating composition or the top coating composition on the coating film obtained from the coating film, the appearance of the coating is uniform and smooth, and there is no "repellency" or unevenness, and a good product can be obtained. Therefore, the plastisol composition of the present invention is suitable as a body sealer or a chipping-resistant agent for vehicles such as automobiles.

Claims (7)

[Claims] 1. A vinyl chloride resin for paste and the resin 1
30 to 400 parts by weight of plasticizer per 30 parts by weight and 30 to
A plastisol composition containing 300 parts by weight of a filler, which is a polyester obtained by polycondensing a dibasic acid and a dihydric alcohol as a plasticizer, and in a dihydric alcohol residue of the polyester. 3-methyl-
A plastisol composition comprising a polyester-based plasticizer containing a 1,5-pentanediol residue in a proportion of 50 mol% or more. 2. A polyester plasticizer having a viscosity at 25 ° C. of 100 to 3000 centipoise (0.1 to 3 Pa).
-S). The plastisol composition according to claim 1. 3. The plastisol composition according to claim 1, wherein the dibasic acid component of the polyester plasticizer has 2 to 10 carbon atoms. 4. The polyester-based plasticizer has 4 carbon atoms at the end.
-13 are blocked with monohydric alcohol.
The plastisol composition according to any one of 1. 5. A polyester plasticizer having 4 carbon atoms at the end.
The plastisol composition according to any one of claims 1 to 3, which is blocked with a monobasic acid of about 12 to 12. 6. A vehicle body sealer comprising the plastisol composition according to any one of claims 1 to 5. 7. A chipping-resistant agent comprising the plastisol composition according to claim 1.