Two-component sealant composition

Abstract

To provide a chloride-based sealant composition that is resistant to air bubbling.SOLUTION: A two-component sealant composition includes a basis and a curing agent. The basis includes a polyvinyl chloride resin, and a polyol compound of 5-15 pts.mass relative to 100 pts.mass of the polyvinyl chloride resin. The curing agent includes a polyvinyl chloride resin, and an isocyanate compound of 60-80 pts.mass relative to 100 pts.mass of the polyvinyl chloride resin.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a two-component sealant composition. [Background technology]

[0002] Generally, thermosetting vinyl chloride sealants are applied to the joints and hems of steel plates in automobiles for the purposes of rust prevention and waterproofing. This vinyl chloride sealant is applied using a special sealing gun. After application, parts such as doors are partially smoothed with a brush or spatula. The sealant then undergoes painting, baking, and other processes before being thermoset, allowing it to function as a sealant.

[0003] However, when conventional PVC sealants are used, the air inside the hem expands during heating, such as baking, and pushes up the sealant applied to the seam as the PVC sealant hardens, causing a blister phenomenon. This blister (hereafter referred to as air blister) not only looks bad, but if it becomes large, the bubbles can break, causing problems such as an inability to ensure rust resistance and waterproofing.

[0004] To address the above problem, various measures have been implemented, such as embedding an adhesive such as a hemming sealant inside the hem to reduce the amount of air in the hem, or adjusting the hemming pressure and other pressing conditions to seal the hem hole opening to suppress air bulging.However, these measures have the problem that they require a large number of items to repair the air bulge and are inefficient.

[0005] Therefore, Patent Document 1 discloses a two-component mixed sealant that is less likely to cause air blistering even when there is space inside, and that can provide a good appearance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-262184 Summary of the Invention [Problem to be solved by the invention]

[0007] The sealant disclosed in Patent Document 1 is 15 mm 3 Although it has a proven track record with small air pockets below 15mm 3 The effectiveness of preventing air bulging with the above air pocket sizes is unknown. 3 There are air pockets exceeding 100mm in size. 3 There is an air pocket of about 100mm. 3 A sealant that does not cause air bulging even in small air pockets is needed.

[0008] Furthermore, the sealant disclosed in Patent Document 1 uses acrylic resin, but from the viewpoint of the storage stability and cost of sealants, there is a demand for the development of a sealant that uses vinyl chloride, which is cheaper and has better storage stability than acrylic resin.

[0009] The present invention has been proposed in view of the above points, and one object of the present invention is to provide a vinyl chloride sealant composition that is less likely to cause air blisters. [Means for solving the problem]

[0010] A two-component sealant composition comprising a base agent and a curing agent, the base material contains a vinyl chloride resin and 5 parts by mass to 15 parts by mass of a polyol compound relative to 100 parts by mass of the vinyl chloride resin, The curing agent contains a vinyl chloride resin and 60 parts by mass to 80 parts by mass of an isocyanate compound relative to 100 parts by mass of the vinyl chloride resin. A two-component sealant composition. [Effects of the Invention]

[0011] According to one aspect of the present invention, a vinyl chloride sealant composition that is less likely to cause air blisters can be provided. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic top view of a test piece for an air swelling test. [Figure 2] FIG. 1 is a schematic perspective view illustrating application of a sealant to a test piece in an air swelling test. [Figure 3] FIG. 2 is a schematic diagram for explaining a method for calculating shear strength. [Figure 4] FIG. 2 is a schematic diagram showing an example of the results of an air swelling test in Example 1 and Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0013] The sealant composition according to this embodiment is described in detail below. The sealant composition according to this embodiment is a two-component vinyl chloride sealant composition, more specifically, a two-component sealant comprising a base agent containing a vinyl chloride resin and a polyol compound and a curing agent containing a vinyl chloride resin and an isocyanate compound.

[0014] The sealant composition of this embodiment temporarily cures the sealant by utilizing room temperature curing of a base agent containing vinyl chloride resin and a polyol compound and a curing agent containing vinyl chloride resin and an isocyanate compound, thereby suppressing swelling of the sealant due to air expansion inside the hem.

[0015] The sealant composition according to this embodiment uses a vinyl chloride resin as the base resin for the main agent and curing agent, and therefore can fully ensure the physical properties required of a sealant after the baking process following application of the sealant, such as elongation, shear strength, etc. On the other hand, if an acrylic resin is used as the base resin for the main agent and curing agent, and a two-component mixed sealant is used, with the main agent containing an acrylic resin and a polyol compound and the curing agent containing an acrylic resin and an isocyanate compound, the elongation, shear stress properties, etc. may decrease.

[0016] The detailed components of each of the base resin and curing agent are described in detail below.

[0017] (Main ingredient) The base component of the sealant composition according to this embodiment preferably contains a urethane resin, a filler, an anti-foaming agent, and a plasticizer in addition to a vinyl chloride resin and a polyol compound.

[0018] The vinyl chloride resin is a resin that serves as the base resin of the main component of the sealant composition according to this embodiment, and may be a vinyl chloride homopolymer or a copolymer containing vinyl chloride as the main component. As the copolymer containing vinyl chloride as the main component, a vinyl chloride copolymer containing vinyl acetate resin or a vinyl chloride copolymer having a polar group in the molecule can be preferably used.

[0019] The polyol compound cures by reacting its own functional group (hydroxyl group) with the functional group (cyano group) of the isocyanate compound curing agent to form a urethane bond. This reaction proceeds at room temperature, so it can be used for the temporary curing of the sealant composition at room temperature. Specific examples of polyol compounds are not particularly limited, but polyol compounds with a hydroxyl group valence of three or more are preferred from the perspective of curing speed. Specific examples include polypropylene glycol (PPG), polytetramethylene ether glycol (PTMG), polyester polyol (PEP), polymer polyol (POP), polybutadiene polyol (PBP), polycarbonate diol (PCD), polycaprolactone polyol (PCL), and trimethylolpropane (TMP).

[0020] In the sealant composition according to this embodiment, the urethane resin serves to aid adhesion to the electrodeposited plate. Specific examples of the urethane resin are not particularly limited, and may include block urethane resin, water-based hard urethane resin, etc.

[0021] The filler serves as a normal filler, and common fillers such as calcium carbonate, barium sulfate, talc, kaolin, and diatomaceous earth can be used.

[0022] The anti-foaming agent serves to prevent the sealant from absorbing moisture and foaming, and metal oxides such as calcium oxide (quicklime) and magnesium oxide, calcium chloride, silicon dioxide (silica gel), synthetic zeolite, deciclay, etc. can be preferably used.

[0023] Plasticizers impart flexibility to materials and include phthalate esters such as diisononyl phthalate (DINP), octylbenzyl phthalate (OBzP), dioctyl phthalate (DOP), dinonyl phthalate (DNP), and diisodecyl phthalate (DIDP); trimellitic acid esters such as trioctyl trimellitate (TOTM); butyl phthalyl butyl glycolate (BPBG), dioctyl azelate (DOZ), and dioctyl sebacate (DOS). Polymeric plasticizers with a molecular weight of approximately 450 or greater are preferred due to their low volatility and excellent resistance to extraction. Specific examples include adipic acid polyesters and phthalic acid polyesters. In this specification, plasticizers with a molecular weight of less than approximately 450 other than polymeric plasticizers are referred to as general-purpose plasticizers or low-molecular-weight plasticizers.

[0024] (hardening agent) The curing agent of the sealant composition according to this embodiment preferably contains a urethane resin, a filler, an anti-foaming agent, and a plasticizer in addition to the vinyl chloride resin and the isocyanate compound.

[0025] As described above, the isocyanate compound reacts with the hydroxyl group of the polyol compound to form a urethane bond, thereby curing. Specific examples of the isocyanate compound include, but are not limited to, polyisocyanate compounds such as hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (polymeric MDI), trimethylhexamethylene diisocyanate (TMDI), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), isophorone diisocyanate (IPDI), and dicyclohexylmethane diisocyanate (HIMDI).

[0026] The vinyl chloride resin, urethane resin, filler, antifoaming agent, and plasticizer that can be used as the curing agent for the sealant composition of this embodiment can be the same as those listed for the main component. These materials have low reactivity with isocyanate compounds and do not interfere with the role of the isocyanate compounds.

[0027] (Containing amount) The blending amounts of each material in the main component of the two-component mixed sealant according to this embodiment are preferably 5 to 15 parts by mass of polyol compound, 25 to 30 parts by mass of urethane resin, 20 to 50 parts by mass of filler, 2 to 10 parts by mass of anti-foaming agent, 0 to 50 parts by mass (50 parts by mass or less) of general-purpose plasticizer, and 50 to 80 parts by mass of polymer plasticizer, relative to 100 parts by mass of vinyl chloride resin.

[0028] Furthermore, the curing agent of the two-component mixed sealant according to this embodiment preferably contains vinyl chloride resin, and contains 60 to 80 parts by mass of an isocyanate compound, 80 to 90 parts by mass of a urethane resin, 140 to 150 parts by mass of a filler, 120 to 140 parts by mass of an anti-foaming agent, and 240 to 260 parts by mass of a general-purpose plasticizer, relative to 100 parts by mass of the vinyl chloride resin.

[0029] The mixing ratio of the main agent to the curing agent is preferably within a volume ratio range of 5 / 6 to 6 / 5, and more preferably a volume ratio of 1. If the volume ratio is outside the above range, the sealant according to this embodiment may not temporarily cure at room temperature.

[0030] When the sealant composition according to this embodiment is used on steel plate joints in automobiles, there are areas (such as the edges of door hem sections) that require smoothing with a brush or spatula after application. This smoothing must be performed with a brush or spatula within a specified time after application. Therefore, the sealant composition must not cure for several minutes after application, then undergo provisional curing, and air blistering after baking must be suppressed. It is also necessary to ensure the required physical properties of the sealant after baking. By adjusting the blending amounts of the polyol compound and isocyanate compound as described above, the curing speed can be adjusted with a brush or spatula for approximately 3 to 5 minutes after application of the sealant, after which the sealant undergoes provisional curing. Furthermore, the sealant according to this embodiment has the physical properties of being able to reduce the height of air blistering to 0.5 mm or less when applied, left for 20 minutes, and then baked. Furthermore, since the sealant according to this embodiment uses a vinyl chloride resin as the base resin and contains other additives in the amounts specified above, it has sufficient physical properties as a sealant after baking.

[0031] Furthermore, by blending the base agent and curing agent in the amounts described above, the sealant according to this embodiment can have a viscosity of 50 to 80 Pa·s, which allows the two components to be easily mixed using a static mixer or the like.

[0032] (Example) The sealant composition according to this embodiment will be described in more detail below with reference to examples.

[0033] Table 1 shows a summary of the types and amounts of various materials used in the examples, comparative examples, and reference examples.

[0034] [Table 1] As shown in Table 1, in Examples 1 to 5, a base resin was prepared by mixing 100 parts by mass of vinyl chloride resin (33 parts of vinyl chloride resin A (vinyl chloride acetate copolymer; PCH-843; manufactured by Kaneka Corporation) and 67 parts of vinyl chloride resin B (a copolymer having polar groups in the molecule; MH-100; manufactured by Kaneka Corporation) for a total of 100 parts by mass) with predetermined amounts of a polyol compound (polyether polyol compound; EDP-300; manufactured by Adeka Corporation), a urethane resin (QR-9401-1; manufactured by Adeka Corporation), a filler (surface-treated calcium carbonate A; Viscolite 30HV; manufactured by Shiraishi Kogyo Co., Ltd.), a general-purpose plasticizer (DINP; manufactured by J-Plus Corporation), a polymer plasticizer (PN-7160; manufactured by Adeka Corporation), and an antifoaming agent (calcium oxide WAC28; manufactured by Sankyo Flour Milling Co., Ltd.). In addition, a curing agent was prepared by mixing 100 parts by mass of vinyl chloride resin A (vinyl chloride acetate copolymer; PCH-843; Kaneka Corporation) with predetermined amounts of an isocyanate compound (UCB-937; ADEKA Corporation), a urethane resin (QR-9401-1; ADEKA Corporation), a filler (surface-treated calcium carbonate A; Viscolite 30HV; Shiraishi Kogyo Co., Ltd.), a general-purpose plasticizer (DINP; J-Plus Corporation), and an antifoaming agent (calcium oxide WAC28; Sankyo Flour Milling Co., Ltd.).

[0035] The sealant of Comparative Example 1 was prepared by mixing 100 parts by mass of vinyl chloride resin consisting of 91 parts vinyl chloride resin A (vinyl chloride acetate copolymer; PCH-843; manufactured by Kaneka Corporation) and 9 parts vinyl chloride resin C (vinyl chloride copolymer; PQHT; manufactured by Shin-Dai-Ichi Vinyl Corporation) with predetermined amounts of urethane resin (QR-9401-1; manufactured by ADEKA Corporation), polyamide (TOMAID 215-X; manufactured by T&K TOKA Corporation), filler (surface-treated calcium carbonate B; manufactured by Takehara Chemical Industry Co., Ltd.), (heavy calcium carbonate A; manufactured by Sankyo Flour Milling Co., Ltd.), general-purpose plasticizer (DINP; manufactured by J-Plus Corporation), and anti-foaming agent (calcium oxide WAC28; manufactured by Sankyo Flour Milling Co., Ltd.).

[0036] The base resin and curing agent of Comparative Examples 2 and 3 were prepared in the same manner as in Example 1, except that the amounts of the polyol compound and the isocyanate compound were changed as shown in Table 1.

[0037] Furthermore, the base resin and curing agent of Comparative Example 4 were prepared in the same manner as in Example 1, except that acrylic resin B (LP3112; manufactured by Mitsubishi Rayon Co., Ltd.) was used instead of the vinyl chloride resin.

[0038] Furthermore, as a reference example, as shown in Table 1, a base resin was prepared by mixing 100 parts by mass of acrylic resin A (F-320; manufactured by Zeon Corporation) with a predetermined amount of polyester polyol compound F148 (manufactured by King Chemical), a filler (heavy calcium carbonate B; manufactured by Takehara Chemical Industry Co., Ltd.), a plasticizer (tricresyl phosphate; manufactured by J-Plus Corporation), and a polymerization catalyst (dibutyltin laurate Scat-1). A curing agent was prepared by mixing 100 parts by mass of acrylic resin A (F-320; manufactured by Zeon Corporation) with an isocyanate compound (diisocyanate-based prepolymer; HDI-based prepolymer D-177N; manufactured by Mitsui Chemicals, Inc.), a filler (heavy calcium carbonate B; manufactured by Takehara Chemical Industry Co., Ltd.), and a plasticizer (tricresyl phosphate; manufactured by J-Plus Corporation). The compositional amounts were the same as those used in the examples of JP 2007-262184 A.

[0039] (evaluation) The sealants obtained in Examples 1 to 5 and Comparative Examples 1 to 4 were subjected to an air swelling test and a hardening confirmation test (spatula repairability) using the following test methods. In addition, the physical properties of the sealants were evaluated, including elongation, tensile strength, and shear strength.

[0040] (Air swelling test) Figure 1 shows a schematic top view of a test piece for the air swelling test. As shown in Figure 1, a 0.8 mm thick steel plate (100 x 300 mm) was used as the air swelling test piece 1. An adhesive was applied to the steel plate, and another steel plate was attached to it and secured with clips. After that, the plate was baked at 180°C for 20 minutes. Five air pockets 2 measuring 10 mm x 20 mm x 0.5 mm in the X-axis x Y-axis x Z-axis dimensions shown in Figure 1 were prepared, and five 5 mm wide outlets were created in each.

[0041] The test conditions for the air swelling test are as follows.

[0042] Sealant shape: Thickness 2.0mm, width 10mm, Air pocket size: 0.5 x 10 x 20 mm = 100 mm 3 , Number of air pockets: 5 Baking conditions: 130°C x 10 minutes (heating up 9 minutes), Storage conditions: 20 minutes at 20°C It was decided.

[0043] Figure 2 shows a schematic perspective view illustrating the application of sealant to a test piece in an air swelling test. As shown in Figure 2, the evaluation method for the air swelling test involves first applying sealant 3 to a test piece 1 for the air swelling test and leaving it for 20 minutes for baking. After baking, the presence or absence of air swelling was confirmed and the height of the air swelling was measured.

[0044] The pass condition for the air bulge height was 0.5 mm or less.

[0045] The test results are shown in Table 2.

[0046] [Table 2]

[0047] Hardening confirmation test (spatula repairability) The test conditions for the hardening confirmation test (spatula repairability) are as follows.

[0048] Sealing material shape: Thickness 2.0mm, width 10mm, Storage conditions: 30°C for 3 minutes, 5 minutes, 10 minutes, 20 minutes, It was decided.

[0049] The evaluation method for the hardening confirmation test (spatula repairability) was to apply the sealant, leave it for a specified time, and then repair it with a spatula at specified times, and check the hardening state from the appearance and the state of the remaining material.

[0050] The criteria for passing the hardening confirmation test (spatula repairability) were that the sealant was uncured for at least 3 minutes and provisionally cured within 20 minutes. Note that "uncured" here means that the sealant is at a level where it can be repaired with a spatula and is easy to smooth out, while "provisionally cured" means that when repaired with a spatula, some sealant remains and it is difficult to smooth out.

[0051] The test results are shown in Table 2.

[0052] (stretch) The elongation of the sealant was measured using a dumbbell-shaped No. 6 sealant with a thickness of 2.0 mm in accordance with the method specified in JIS K 6301.

[0053] The evaluation method was to apply each sealant to a release paper at a thickness of 2 mm, bake it at 140°C for 20 minutes, leave it overnight, and then pull it at a pulling speed of 50 mm / min to calculate the elongation at break.

[0054] The elongation requirement was 150% or more.

[0055] The test results are shown in Table 2.

[0056] (tensile strength) The tensile strength of the sealant was measured using a dumbbell-shaped sealant No. 6 with a thickness of 2.0 mm according to the following method.

[0057] Each sealant was applied to a release paper at a thickness of 2 mm, baked at 140°C for 20 minutes, and left overnight. After leaving, the sealant was pulled at a pulling speed of 50 mm / min, and the tensile strength at break was calculated.

[0058] The pass criteria for tensile strength were that the sealant had a tensile strength equal to or greater than that of the sealing material of the comparative example.

[0059] The test results are shown in Table 2.

[0060] (shear strength) A schematic diagram for explaining the method for calculating shear strength is shown in Figure 3. More specifically, the upper diagram of Figure 3 shows a schematic top view of the steel plate on which shear strength was measured, and the lower diagram of Figure 3 shows a schematic side view of the steel plate on which shear strength was measured. The shear strength of the sealant was measured using the following method using sealant 3 measuring 12.5 mm x 25 mm x 2.0 mm in the X-axis x Y-axis x Z-axis shown in Figure 3.

[0061] Using each sealant, two 100 mm x 25 mm electrodeposition-coated steel plates (shown as steel plate 4 and steel plate 5 in Figure 3) were prepared. Sealant 3 was applied to the edge of one steel plate, and the other edge was overlapped. Spacers 6 were placed on both sides of the overlapping sealant and secured with clips 7. The plates were then baked at 140°C for 20 minutes and left overnight. After leaving the plates, they were pulled at a tensile speed of 10 mm / min, and the shear strength at break was calculated. The adhesion to the steel plate after break was also confirmed.

[0062] The pass criteria for shear strength were a strength of 568 kPa or more and cohesive failure in adhesion to the steel plate.

[0063] The test results are shown in Table 2.

[0064] (Evaluation results) Figure 4 shows a schematic diagram illustrating an example of the results of the air swelling test in Example 1 and Comparative Example 1. The upper diagram in Figure 4 is a schematic diagram of Example 1 after the air swelling test, and the lower diagram in Figure 4 is a schematic diagram of Comparative Example 1 after the air swelling test. Note that the positions of air pockets in Figure 4 are circled.

[0065] As shown in Fig. 4 and Table 2, the sealants of Examples 1 to 5 passed the air blister test and the cure confirmation test (spatula repairability), and also passed the provisional cure (pre-gel property) and initial physical properties. On the other hand, the sealants of Comparative Examples 1 and 2 failed the air blister test and the cure confirmation test (spatula repairability), and the sealant of Comparative Example 3 failed the cure confirmation test (spatula repairability). Furthermore, the sealant of Comparative Example 4 failed the elongation test, which is a physical property required for a sealant.

[0066] That is, when an acrylic resin is used as the base resin of the main agent and curing agent, the physical properties required for a sealant cannot be sufficiently secured, and it was found that it is preferable to use a vinyl chloride resin as the base resin.Furthermore, it was found that the preferred blending amounts of the polyol compound and isocyanate compound of the main agent and curing agent are 5 to 15 parts by mass and 60 to 80 parts by mass, respectively, per 100 parts by mass of the vinyl chloride resin. [Explanation of symbols]

[0067] 1. Air swelling test specimen 2 air pockets 3. Sealant 4 steel plate 5 steel plate 6 spacers 7 clips

Claims

1. A two-component sealant composition comprising a base agent and a curing agent, the base material contains a vinyl chloride resin and 5 to 15 parts by mass of a polyol compound relative to 100 parts by mass of the vinyl chloride resin; The curing agent contains a vinyl chloride resin and 60 parts by mass to 80 parts by mass of an isocyanate compound per 100 parts by mass of the vinyl chloride resin. A two-component sealant composition.

2. The base agent further contains, relative to 100 parts by mass of the vinyl chloride resin contained in the base agent, 25 parts by mass to 30 parts by mass of a urethane resin, 20 parts by mass to 50 parts by mass of a filler, 2 parts by mass to 10 parts by mass of a foam inhibitor, 50 parts by mass or less of a low-molecular-weight plasticizer, and 50 parts by mass to 80 parts by mass of a polymer plasticizer; The curing agent further contains, relative to 100 parts by mass of the vinyl chloride resin contained in the curing agent, 80 parts by mass to 90 parts by mass of a urethane resin, 140 parts by mass to 150 parts by mass of a filler, 120 parts by mass to 140 parts by mass of a foam inhibitor, and 240 parts by mass to 260 parts by mass of a low-molecular-weight plasticizer. The two-component sealant composition according to claim 1 .

3. The ratio of the base agent to the curing agent is within the range of 5 / 6 to 6 / 5 in volume ratio. The two-component sealant composition according to claim 1 or 2.

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