JP2015189969A - sealant composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealant composition for automobiles having excellent weather resistance.SOLUTION: In a sealant composition for automobiles according to the present invention, based on 100 pts.wt. of polyvinyl chloride resin containing 10-50 pts.wt. of polyvinyl chloride resin with a crosslinkable property imparted thereto, 10-50 pts.wt. of urethane resin, and 70-150 pts.wt. of adipic acid ester plasticizer and 10-60 pts.wt. of citric acid ester plasticizer as plasticizers are contained.

Description

  The present invention relates to an automotive sealing material composition, and more particularly to an automotive sealing material composition having excellent weather resistance.

  Vinyl chloride sealing materials are widely used for rust prevention and waterproofing in automobile steel plate joints and steel plate hemming parts. In addition, such a sealing material is widely used in a steel plate joint portion of a roof portion of an automobile (see, for example, Patent Document 1).

  In the roof portion, the sealing material is applied by a special sealing gun and smoothed by a brush or a spatula. Thereafter, the roof portion is painted, and the sealing material is thermally cured by passing through a baking furnace, so that a rustproofing and waterproofing effect can be obtained. Furthermore, in order to improve the designability, a plastic molding of a resin molded product is generally mounted on the sealing material.

  This plastic molding has low heat resistance and cannot be attached before a coating process having a high heat drying process. For this reason, the plastic molding is attached after the roof portion (vehicle body) is painted, and it is difficult to make the plastic molding and the vehicle body completely the same color.

  Therefore, it is conceivable to use the sealing material disclosed in Patent Document 1 or the like for the roof portion without using a plastic molding.

  However, the sealing material disclosed in Patent Document 1 and the like is not designed on the assumption that the sealing material is used in places that are always exposed to the outside, such as a roof portion. For this reason, the conventional sealing material as disclosed in Patent Document 1 does not satisfy the weather resistance required for the roof portion over the long term, and causes problems such as cracks.

JP 2012-62442 A

  The present invention has been made in consideration of such circumstances, and an object thereof is to provide an automotive sealing material composition having excellent weather resistance.

  In order to solve the above-described problems, the automotive sealing material composition according to the present invention is a urethane resin with respect to 100 parts by weight of a vinyl chloride resin containing 10 to 50 parts by weight of a vinyl chloride resin imparted with crosslinkability. 10 to 50 parts by weight, 70 to 150 parts by weight of an adipic ester plasticizer as a plasticizer, and 10 to 60 parts by weight of a citrate ester plasticizer.

  The automotive sealing material composition according to the present invention can have excellent weather resistance.

The cross-sectional block diagram explaining the test piece used by the Example and the comparative example.

  The automotive sealing material composition in the present embodiment mainly contains a vinyl chloride resin, a urethane resin, and a plasticizer including an adipate ester system and a citrate ester system.

  Examples of the vinyl chloride resin include (1) vinyl chloride paste resin produced by emulsion polymerization of vinyl chloride alone or a comonomer copolymerizable with vinyl chloride in the presence of an emulsifier and a water-soluble polymerization initiator, (2 ) A polymer produced by a fine suspension polymerization method in which vinyl chloride alone or a comonomer copolymerizable with vinyl chloride is mechanically finely dispersed and then polymerized in the presence of a dispersant and an oil-soluble polymerization initiator can be used. In addition to these, a vinyl chloride resin having a relatively large particle size produced by ordinary suspension polymerization may be used in combination. Examples of the copolymerizable comonomer include vinyl esters such as vinyl acetate, hydroxypropyl acrylate, vinyl propionate and vinyl laurate; acrylic esters such as methyl acrylate, ethyl acrylate, butyl acrylate and hydroxyethyl acrylate; Methacrylic acid esters such as methyl methacrylate, ethyl methacrylate and hydroxyethyl methacrylate; Maleic acid esters such as dibutyl maleate and diethyl maleate; Fumarate esters such as dibutyl fumarate and diethyl fumarate; Vinyl methyl ether and vinyl butyl ether , Vinyl ethers such as vinyl octyl ether; vinyl cyanides such as acrylonitrile and methacrylonitrile; ethylene, propylene Α-olefins such as styrene and styrene; vinylidene chloride such as vinylidene chloride or vinyl bromide or other vinyl halides, and the like. At least one of these is 30% by mass or less, preferably 20% by mass % Or less can be copolymerized. A polymerization degree shall be 1000-3000 as what polymerized the said vinyl chloride single-piece | unit or the comonomer copolymerizable with vinyl chloride.

  A vinyl chloride resin having a crosslinking property copolymerized with the comonomer shown in the above (1) and (2) (hereinafter simply referred to as “special vinyl chloride”) is composed of an OH group and a urethane resin in the special vinyl chloride. Can react to form a crosslinked structure. For this reason, a stronger coating film can be formed and a weather resistance performance can be improved more.

  As the urethane resin, a blocked isocyanate-containing type in which a blocking agent is reacted with an isocyanate group can be used. Isocyanate types include tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, etc. Can be used as a base.

  Examples of the adipate ester plasticizer include dimethyl adipate (DMA), dibutyl adipate (DBA), diisobutyl adipate (DIBA), di-2-ethylhexyl adipate (DOA), diisononyl adipate (DINA), bis (butyl diglycol) ) Adipate (BXA-R), diisodecyl adipate (DIDA), di-2-ethylhexyl azelate (DOZ) can be used. In addition, various adipic acid ester-based polyesters having a higher ester portion can be used, and adipic acid polyesters having a particularly high molecular weight (for example, a molecular weight of about 800 to 2200) are preferred.

  When only a conventionally used plasticizer such as diisononyl phthalate (DINP) or bis (DOP) phthalate is used, the plasticizer gradually moves to the coating film when exposed to the outside air for a long time. As a result, the sealing material may be discolored or cracked. On the other hand, it can suppress that a plasticizer transfers to a coating film by containing an adipic acid ester type plasticizer. As a result, the weather resistance of the sealing material can be improved, and glossing and cracking can be suppressed.

  Examples of the citrate plasticizer include triethyl citrate (TEC), acetyl triethyl citrate (ATEC), tributyl citrate (TBC) acetyl tributyl citrate (ATBC) trioctyl citrate (TOC), and acetyl trioctate. Alkyl citrate plasticizers such as silcitrate (ATOC), trihexyl citrate (THC), and acetyl trihexyl citrate (ATHC) can be used, and acetyl tributyl citrate (ATBC) is particularly preferable.

  By using an adipate ester plasticizer, the weather resistance and the like can be improved as described above. However, depending on the baking conditions, so-called baked sweetness (insufficient heating, poor drying) may occur. As a result, the sealing material becomes insufficiently gelled, resulting in blistering (a state where the adhesion between the coating film and the coating film decreases and the coating film swells and floats), which is a swelling caused by agglomeration of the plasticizer. There is a fear. On the other hand, by containing a citrate ester plasticizer, gelation of the sealing material can be promoted, and the generation of blisters can be suppressed.

  It also contains plasticizers other than adipate ester plasticizers such as diisononyl phthalate (DINP) and bisphthalate (DOP) and citrate plasticizers (hereinafter simply referred to as “plasticizers such as DINP”). May be. By containing a plasticizer such as DINP, it is easy to adjust the viscosity because of its low molecular weight, and it is preferable in terms of cost-effectiveness compared to adipic acid ester and citric acid ester plasticizers. On the other hand, since plasticizers such as DINP have a low molecular weight, when they are coated on the sealing material, they shift to each other between the solvent content in the paint and the plasticizer in the sealing material. As a result, the weather resistance performance of each of the sealing material and the paint is reduced. For this reason, when using a plasticizer such as DINP, it is necessary to determine the amount within a range not impairing the weather resistance (for example, 0 to 30 parts by weight with respect to 100 parts by weight of the vinyl chloride resin). By using a higher molecular weight adipic acid ester plasticizer and citrate ester plasticizer together with a plasticizer such as DINP, the plasticizer of DINP can be used as compared with the conventional case where a plasticizer such as DINP is used alone. Transferability to paint can be suppressed.

  In this embodiment, the vinyl chloride resin contains 10 to 50 parts by weight of special vinyl chloride out of 100 parts by weight.

  A urethane resin is 10-50 weight part with respect to 100 weight part of vinyl chloride resin, Preferably it is 20-30 weight part. When the urethane resin is less than 10 parts by weight, the adhesion to the vehicle steel plate surface coated with ED (Electrical Discharge) is hindered. On the other hand, when the amount of the urethane resin exceeds 50 parts by weight, the viscosity becomes high and it is difficult to use it in the coating equipment.

  The adipate plasticizer is, for example, 70 to 150 parts by weight, preferably 100 to 130 parts by weight with respect to 100 parts by weight of the vinyl chloride resin. When the adipic acid ester plasticizer is less than 70 parts by weight, it is difficult to use it in a coating facility because of its high viscosity. On the other hand, when the amount of adipic acid ester plasticizer exceeds 150 parts by weight, the gelation rate becomes slow, so that blisters are likely to occur.

  The citrate plasticizer is, for example, 10 to 60 parts by weight, preferably 30 to 50 parts by weight, based on 100 parts by weight of the vinyl chloride resin. When the citrate plasticizer is less than 10 parts by weight, blistering is likely to occur. On the other hand, when the citrate plasticizer exceeds 60 parts by weight, glossiness tends to occur.

  When the plasticizer contains a plasticizer such as DINP, the plasticizer such as DINP is 0 to 30 parts by weight with respect to 100 parts by weight of the vinyl chloride resin. When the amount exceeds 30 parts by weight, the plasticizer gradually moves to the coating film when exposed to the outside air for a long time.

  In addition, if the content of plasticizers such as adipic acid ester plasticizer, citrate ester plasticizer, and DINP is too much or too little, it becomes high viscosity or low viscosity, and is used as a sol composition. Becomes difficult. Uses other than the proper viscosity will cause problems in the work process. For this reason, it is preferable that it is 160 weight part used as the median of the maximum minimum amount (80-320 weight part) of the plasticizer total amount mentioned above.

  In the automotive sealing material composition of the present invention, in addition to the above components, additives such as a light stabilizer, a moisture absorption inhibitor and a filler can be selected and added as necessary.

  As the light stabilizer, for example, a hindered amine light stabilizer (HALS) can be used. By adding HALS, long-term radical scavenging is possible, and deterioration of the sealing material can be prevented in the long term.

  As the moisture absorption inhibitor, for example, calcium oxide can be used.

  As the filler, for example, at least one of inorganic fillers such as calcium carbonate, barium sulfate, clay, diatomaceous earth, silica, and talc can be used. Moreover, hollow particles, such as a glass balloon and a resin balloon, can also be mix | blended as needed.

  The automotive sealing material composition in the present embodiment is applied as a sealing material to a steel plate joint portion of an automobile, a hem-processed portion of a steel plate, and the like. In particular, the sealing material composition in the present embodiment is applied as a sealing material to the roof portion of an automobile. In addition to automobile vehicles, the present invention can be applied to parts that require weather resistance, such as vending machines, railway vehicles, and houses.

  The sealing material is embedded (applied) in, for example, a steel plate joint by a robot (application means). The joint part to which the sealing material is applied is, for example, pre-baked at 120 ° C., and then painted according to the color of the vehicle body and baked again.

  Since the sealing material composition in the present embodiment is a one-component thermosetting type and is cured using a paint oven in an automobile manufacturing process, the problems of management, use, and safety of the two-component thermosetting type are as follows. It cannot happen. Moreover, it can be used for a roof part of an automobile or the like, and weather resistance and design properties can be secured without using a plastic molding (roof molding).

  Hereinafter, although the sealing material composition for motor vehicles concerning the present invention is explained still more concretely using an example, the present invention is not limited by the following examples, unless the gist is exceeded.

[Sealing material composition]
In the following examples and comparative examples, the sealing material composition is a vinyl chloride resin (general purpose) (R850 manufactured by Tosoh Corporation), hydroxypropyl acrylate (manufactured by Kaneka Corporation, MH-100) as a special vinyl chloride, and a urethane resin. Blocked isocyanate (manufactured by Sanyo Kasei Kogyo Co., Ltd., Keomix KA-112), plasticizer as adipate ester plasticizer (J-Plus, D620), citrate ester plasticizer (J-Plus, ATBC) Contained. In addition, as a plasticizer such as DINP, DINP (manufactured by J-Plus, DINP), as an additive for sealing material composition, as a moisture absorption inhibitor (Omi Chemical Industries, CML-35), as a filler (Manufactured by Shiraishi Calcium Co., Ltd., Hacuenka CCR) and light stabilizer (HALS) (manufactured by BASF, TINUVIN123).

[Test piece]
In the test, the test piece 1 shown in FIG. 1 was used. The test piece 1 is a steel plate in which a concave portion 2 is formed, and a sealing material composition 3 is embedded in the concave portion 2. The recess 2 has, for example, dimensions of 20 mm in width, 30 mm in depth, and 10 mm in height, and the sealing material composition 3 is embedded up to a height of 10 mm. The test piece 1 is applied by, for example, a robot (application means). For example, the test piece 1 is preliminarily baked at 120 ° C., then painted, and baked again at 140 ° C.

[Test method]
<Weather resistance>
The weather resistance was tested by irradiating the test piece 1 with light so as to be perpendicular to the seal surface. As the light resistance tester, a xenon weather meter (manufactured by Suga Test Instruments Co., Ltd., model number: SX75) was used. Test conditions are: irradiance: 180 W / m ² (400 nm or less), temperature: 63 ± 3 ° C. during irradiation, 28 ± 3 ° C. during rainfall, humidity: 50% ± 5% RH during irradiation, 95% RH or more during rainfall, Rainfall cycle: Rain for 24 minutes during irradiation for 360 minutes. The test time was 2500 hours.
<Viscosity>
Automotive standards: Based on body sealant (JASO) viscosity test A method.
Measuring instrument: VISCOMETER (TOKI SANGYO CO., LTD)
Model: 10H
Rotor number: 7 Number of rotations: 20 rpm
<Shear adhesion strength>
Automotive standards: Based on body sealant (JASO) shear adhesion strength test.
Test piece shape: Thermosetting irregular seal material
However, the baking conditions are maintained at 140 ° C. for 20 minutes.
Testing machine: Shimadzu Autograph AG-2000C type

[Evaluation method]
<Weather resistance>
The test piece 1 after the experiment was visually evaluated for cracks, blisters and gloss. With respect to gloss, blister, and cracks, those that did not change in appearance after 2500 hours of xenon addition were marked with ◯ and those that changed in appearance within 2500 hours.
<Viscosity>
The viscosity range was 50 to 150 Pa · s, and the range within this range was marked with ◯, and the range outside this range was marked with ×.
<Shear adhesion strength>
Evaluate adhesion (peeling state) with a testing machine. For those in which cohesive failure occurred, CF (Cohesive Failure) was used. In some cases, interfacial peeling occurred as AF (Adhesive Failure). In this example, even a part of the interface peeled was evaluated as inappropriate.

(Examples 1 to 3, Comparative Examples 1 and 2)
The sealing material composition 3 contained 100 parts by weight of a vinyl chloride resin containing 20 parts by weight of special vinyl chloride, 30 parts by weight of a urethane resin, 40 parts by weight of a moisture absorption inhibitor, and 120 parts by weight of a filler. Further, 120 parts by weight of an adipate ester plasticizer and a citrate ester plasticizer as plasticizers were changed between 0 to 70 parts by weight as shown in Table 1.

(Examples 4 to 7, Comparative Examples 3 and 4)
The sealing material composition 3 contained 100 parts by weight of a vinyl chloride resin containing 20 parts by weight of special vinyl chloride, 30 parts by weight of a urethane resin, 40 parts by weight of a moisture absorption inhibitor, and 120 parts by weight of a filler. Further, as shown in Table 1, 40 parts by weight of a citrate ester plasticizer and an adipate ester plasticizer were contained as plasticizers while being changed between 60 to 170 parts by weight.

(Examples 8 to 10, Comparative Example 5)
The sealing material composition 3 contained 100 parts by weight of a vinyl chloride resin, 30 parts by weight of a urethane resin, 40 parts by weight of a moisture absorption inhibitor, and 120 parts by weight of a filler. Among 100 parts by weight of the vinyl chloride resin, the special vinyl chloride was changed between 0 to 50 parts by weight as shown in Table 1. Further, 120 parts by weight of adipic ester plasticizer and 40 parts by weight of citrate plasticizer were contained as plasticizers.

(Examples 11 to 14, Comparative Examples 6 and 7)
As shown in Table 1, 0 to 60 parts by weight of 100 parts by weight of a vinyl chloride resin containing 20 parts by weight of special vinyl chloride, 40 parts by weight of a moisture absorption inhibitor, 120 parts by weight of a filler, and a urethane resin as the sealing material composition 3 The content was changed between. Further, 120 parts by weight of adipic ester plasticizer and 40 parts by weight of citrate plasticizer were contained as plasticizers.

(Example 15)
The sealing material composition 3 contained 100 parts by weight of a vinyl chloride resin containing 20 parts by weight of special vinyl chloride, 30 parts by weight of a urethane resin, 40 parts by weight of a moisture absorption inhibitor, and 120 parts by weight of a filler. Further, 120 parts by weight of an adipate plasticizer, 40 parts by weight of a citrate plasticizer, and 30 parts by weight of DINP were contained as plasticizers.

(Example 16)
In the sealing material composition 3 of Example 15, 3 parts by weight of a light stabilizer (HALS) was further contained.

(Comparative Examples 8-11)
The sealing material composition 3 contained 100 parts by weight of a vinyl chloride resin containing 20 parts by weight of special vinyl chloride, 30 parts by weight of a urethane resin, 40 parts by weight of a moisture absorption inhibitor, and 120 parts by weight of a filler. Further, as a plasticizer, 160 parts by weight of DINP for Comparative Example 8, 160 parts by weight of an adipate ester plasticizer for Comparative Example 9, 160 parts by weight of citrate ester plasticizer for Comparative Example 10, and Comparative Example 11 About 120 parts by weight of adipic acid ester plasticizer and 40 parts by weight of DINP were contained.

  As shown in Table 1, in Comparative Example 8 using only DINP as a plasticizer that has been widely used in the past, glossing and cracking occurred. In Comparative Examples 1 and 9 using only the adipic ester plasticizer, blistering occurred although cracking and glossiness were improved. Further, in Comparative Example 10 using only the citrate ester plasticizer, glossiness was generated. Furthermore, in Comparative Example 11 using the adipate ester plasticizer and DINP, cracks occurred. Furthermore, although both adipic acid ester plasticizer and citrate plasticizer were used, citrate plasticizer was not within the range of 10 to 60 parts by weight, Comparative Examples 1 and 2, adipic acid plastic In Comparative Examples 3 and 4 in which the agent was not within the range of 70 to 150 parts by weight, blistering and glossing occurred, and the viscosity was inferior, leading to a decrease in facility workability.

  On the other hand, in Examples 1-16 which suitably used the plasticizer of the adipic acid ester type and the citrate ester type as shown in Table 1, it was found that all the evaluation items were improved. When it is 100 to 130 parts by weight with respect to 100 parts by weight of the vinyl chloride resin, which is a particularly preferable range of the adipate ester plasticizer (Examples 1 to 3, 5, 6, 8 to 16), gloss or blister It was found that a viscosity that is less likely to occur (more safe) and has good workability can be obtained. The same applies to the case of 30 to 50 parts by weight (Examples 2 and 4 to 16) with respect to 100 parts by weight of the vinyl chloride resin, which is a particularly preferable range of the citrate plasticizer.

  In Example 15 containing 30 parts by weight of DINP, good evaluation was obtained for all items. Thereby, for example, in the case of obtaining efficiency from the viewpoint of production cost, by containing an appropriate amount of DINP in the adipic acid ester / citrate plasticizer, glossiness is not generated and the production cost is excellent. A sealant composition can be obtained. Further, in Example 16 containing 3 parts by weight of HALS, glossiness can be further improved.

  In addition, as shown in Examples 11 to 14, by containing 10 to 50 parts by weight of urethane resin, it is excellent in shear adhesion strength and viscosity, and can suitably obtain adhesion to the steel sheet surface and facility workability. it can.

  Furthermore, as shown in Examples 8 to 10, the generation of blisters can be suppressed by containing 10 to 50 parts by weight of special vinyl chloride in 100 parts by weight of the vinyl chloride resin.

1 Test piece 2 Recess 3 Sealant composition

Claims (6)

  10 to 50 parts by weight of a urethane resin and 70 to 150 parts by weight of an adipate ester plasticizer as a plasticizer with respect to 100 parts by weight of a vinyl chloride resin containing 10 to 50 parts by weight of a vinyl chloride resin imparted with crosslinkability And a citrate plasticizer in an amount of 10 to 60 parts by weight.   The sealing material composition according to claim 1, wherein the adipate ester plasticizer is 100 to 130 parts by weight with respect to 100 parts by weight of the vinyl chloride resin.   The sealing material composition according to claim 1 or 2, wherein the citrate plasticizer is 30 to 50 parts by weight with respect to 100 parts by weight of the vinyl chloride resin.   The sealing material composition according to any one of claims 1 to 3, wherein the urethane resin is 20 to 30 parts by weight with respect to 100 parts by weight of the vinyl chloride resin.   The sealing material composition according to any one of claims 1 to 4, further comprising a light stabilizer.   The sealing material composition according to any one of claims 1 to 5, wherein the sealing material composition is an automotive sealing material.

Images