JPH0457191B2 - - Google Patents

Description

[Detailed description of the invention]

OBJECT OF THE INVENTION (Field of Industrial Application) The present invention relates to a molding attached to the body, bumper, etc. of an automobile, and more specifically to a resin molding having a tape attached to the back surface thereof. (Prior Art) Moldings made of synthetic resin or synthetic rubber are attached to the bodies and bumpers of automobiles. The base material for the above molding is generally vinyl chloride resin or EPDM (ethylene-propylene-
Polyolefin-based vulcanized rubbers such as diene terpolymer rubber) and EPM (ethylene-propylene copolymer rubber) are used. A molding that is attached to the side of the body and has the function of preventing scratches caused by contact with other objects when opening a door, etc., and also has a decorative function is called a side protection molding.It is a tape coated with adhesive or adhesive. It is now attached to the body etc. using so-called double-sided tape. In other words, by adopting a method of attaching the molding base material to the body etc. via tape, the installation work is simplified, and since there is no need to drill holes in the body, there is an advantage that rust does not occur. It is. As the base material for the tape, a sponge made of polyethylene, acrylic rubber, chloroprene rubber, etc. formed into a thin plate, nonwoven fabric, film, paper, or the like is used. The adhesive applied to the surface of the tape may be an acrylic composition whose main component is an acrylic resin such as butylene acrylate, butyl methacrylate, or 2-ethylhexyl acrylate, or a chloroprene composition whose main component is polychloroprene. Compositions are common. (Problem to be solved by the invention) However, since polyolefin polymers such as EPDM, EPM, and polyethylene do not contain polar groups in the main chain of their molecules, they cannot be coated with paint, adhesive, pressure-sensitive adhesive, etc. on the surface. It is known that even when applied, the adhesion of the resulting coating film is insufficient. Therefore, even if the molding base material and the tape are bonded together using adhesive or pressure-sensitive adhesive, if either the molding base material or the tape is made of polyolefin polymer, the problem is that the adhesion is insufficient. There is a point. In addition, when the molding base material made of vinyl chloride resin is attached to a body etc., due to temperature differences between day and night, and between summer and winter,
The base material repeatedly contracts and expands. The base material shrinks due to the action of the low molecular weight compound in the resin. Due to interactions with heat, light, moisture, etc., the flexibilizers and stabilizers in the resin decompose and become low molecular weight, which evaporate into the air, causing the base material to shrink. It has been pointed out that due to various factors such as these, the adhesion of the adhesive (or pressure-sensitive adhesive) applied between the molding base material and the tape decreases. As a result of repeated research aimed at solving the above problems, the present inventor has developed a composition that has strong adhesion to resin moldings made of EPDM, vinyl chloride resin, etc., or tapes made of polyethylene, etc. By discovering this, we have arrived at the present invention. Structure of the Invention (Means for Solving Problems) The present invention comprises a molding base material and a tape attached to the back surface thereof, and between the back surface of the molding base material and the tape, (a) an undercoat is provided. A chlorinated polyolefin with a degree of chlorination of 5 to 60% is applied as an agent, and (b) an active hydrogen-containing acrylic adhesive is used as a top coat.
Urethane prepolymer 0.007 per 100 parts by weight
~10 parts by weight or polyisocyanate 0.007~
A molding characterized by being formed by applying a mixture containing 2500 parts by weight was adopted. (Function) By coating the surface of the base material (molding and/or tape) made of polyolefin polymer or vinyl chloride resin with a primer and a top coat having the above composition, the adhesion between the molding base material and the tape is improved. Since it is significantly strengthened, if it is attached to an automobile body or bumper, it will be difficult to peel off even after long-term use. [First Embodiment] As shown in Fig. 1, the mall of this embodiment has the following features:
It is composed of a molding base material 1a made of EPDM, a tape 4a made of a 5-fold foam of chloroprene rubber, and an undercoat 2 and a topcoat 3 applied to the back surface of the molding base material 1a.

[Table] The mall base 1a made of the above EPDM is shown in Table-1.
It was produced by extruding EPDM having the composition shown and then heating it at 200°C for 5 minutes. Next, regarding the composition of the base coat and top coat,
explain. The primer is chlorinated polypropylene (hereinafter referred to as Cl-PP) with a degree of chlorination of 5 to 60%. If the degree of chlorination is less than 5%, the polarity will decrease, and if the degree of chlorination is 60% or more, the polarity will be too high, resulting in a decrease in adhesion. This primer is diluted with an organic solvent and applied to the molding base 1.
The organic solvent used is n-
Saturated hydrocarbons such as hexane and cyclohexane; Aromatic hydrocarbons such as benzene, toluene, and xylene; Ethers such as dioxane and tetrahydrofuran; Acetate esters such as ethyl acetate and propyl acetate; Ketones such as acetone, cyclohexanone, and methyl ethyl ketone. Examples include one selected solvent or a mixture of two or more selected solvents. In addition, preferred dilution level Cl - solid content concentration of PP =
It is about 10-70%. Further, the top coating agent is a mixture of an active hydrogen-containing acrylic adhesive and a urethane prepolymer, or a mixture of an active hydrogen-containing acrylic adhesive and a polyisocyanate. The active hydrogen-containing acrylic pressure-sensitive adhesive is obtained by polymerizing acrylic acid, methacrylic acid, or a mixture of two or more of these derivatives, and the following active hydrogen compound in the above-mentioned organic solvent. Specifically, the above acrylic acid derivatives include methyl acrylate, ethyl acrylate, n-butyl acrylate, iso-butyl acrylate, 2-ethylhexyl acrylate, isodecyl acrylate, 2-hydroxyethyl acrylate, 2-
Examples include hydroxypropyl acrylate, glycidyl acrylate, and dimethylaminoethyl acrylate. In addition, methacrylic acid derivatives include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate,
-ethylhexyl methacrylate, isodecyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,
Examples include glycidyl methacrylate and dimethylaminoethyl methacrylate. Furthermore, as active hydrogen compounds, the above-mentioned acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate,
In addition to 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate, organic acids such as maleic acid, maleic anhydride, fumaric acid, citraconic acid, citraconic anhydride, itaconic acid, and itaconic anhydride can be exemplified. A specific example of the active-containing acrylic pressure-sensitive adhesive having the above composition will be shown below. Acrylic adhesive-A: A mixed solvent consisting of toluene/cyclohexane/ethyl acetate = 1/1/1 (weight ratio) is added to a copolymer of n-butyl acrylate and maleic anhydride (acid value = 20 to 25). (37% solids). Acrylic adhesive-B: A mixed solvent consisting of toluene/cyclohexane/ethyl acetate = 1/1/1 (weight ratio) was added to a copolymer of n-butyl acrylate and fumaric acid (acid value = 30 to 32). (37% solids). Acrylic adhesive-C: Copolymer of n-butyl acrylate and 2-hydroxyethyl methacrylate (hydroxyl value = 54 ~
58) toluene/cyclohexane/ethyl acetate=
A mixed solvent consisting of 1/1/1 (weight ratio) was added (solid content 37%). Acrylic adhesive-D: Copolymer of n-butyl acrylate and 2-hydroxypropyl methacrylate (hydroxyl value = 26
~30) was added with a mixed solvent consisting of toluene/cyclohexane/ethyl acetate 1/1/1 (weight ratio) (solid content 37%). Next, the urethane prepolymer is a polyester urethane prepolymer (or polyether urethane prepolymer) consisting of a polyester polyol (or polyether polyol) and a polyisocyanate. Polyol components of polyester polyol include ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,5
Examples include -pentanediol, 1,6-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and trimethylolpropane. In addition, organic acid components include succinic acid, phthalic acid, phthalic anhydride, isophthalic acid, maleic acid,
Examples include dicarboxylic acids such as adipic acid, azelaic acid, and sebacic acid. On the other hand, examples of polyether polyols include polyoxypropylene diol, polytetramethylene glycol ether, and polyoxyethylene diol. In addition to the above-mentioned examples, various polyols can be used, such as chloroprene rubber and acrylic resin. Next, as polyisocyanates, 2,4-tolylene diisocyanate, hydrogenated 2,4-tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, 1,5- Polymers of various diisocyanates such as naphthalene diisocyanate, xylene diisocyanate, hydrogenated xylene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, or 4,4',4''-triphenylmethane triisocyanate, tris-(p-isocyanate enil)
- Polymers of various polyfunctional isocyanates such as thiophosphate can be exemplified. To produce this top coat, 0.007 to 10 parts by weight of a urethane prepolymer may be mixed with 100 parts by weight of the active hydrogen-containing acrylic adhesive (A to D) in an organic solvent. When mixing, if the urethane prepolymer is less than 0.007 parts by weight, it will not be effective.
Moreover, if it is more than 10 parts by weight, problems such as the hardness of the obtained top coating agent will be too high and the pot life will be shortened. Further, the top coat may be a mixture of the active hydrogen-containing acrylic adhesive (A to D) and polyisocyanate in an organic solvent. In this case, the mixing ratio is 0.007 to 2,500 parts by weight of the polyisocyanate to 100 parts by weight of the active hydrogen-containing acrylic adhesive. If the polyisocyanate is less than 0.007 parts by weight, there will be no effect, and if it is more than 2,500 parts by weight, problems such as the hardness of the resulting top coat will be too high and the pot life will be shortened. Next, in order to measure the adhesion between the molding base material 1a and the tape 4a, a test was conducted using the following method. Test method: Primer 2 was applied to the back side of molding base material 1a made of EPDM and air-dried for 30 minutes at room temperature, then topcoat 3 was applied thereon, and tape 4a made of 5x foam of chloroprene rubber was applied. They were pasted together and dried at 100°C for 2 minutes. Next, this molding was left at room temperature (25° C.) for 20 days, and then the shear strength was measured at a tensile rate of 30 mm/min, and the results shown in Table 2 were obtained. The compositions of the base coat 2 and top coat 3 used are as follows. (All organic solvents used were toluene/cyclohexane/ethyl acetate = 1/1/1
[Weight ratio]. ) Test-1 Primer: Cl-PP with a degree of chlorination of 5% (solid content = 10
%) Finishing agent: A mixture consisting of 100 parts by weight of acrylic adhesive A and 1.0 parts by weight of polyester urethane prepolymer with tolylene diisocyanate added to both molecular ends of polyethylene adipate (molecular weight = approximately 2000) (solid content = 37 %) Test-2 Primer: Cl-PP with chlorination degree of 13% (solid content = 20
%) Topcoat: Consists of 100 parts by weight of acrylic adhesive B and 5.0 parts by weight of polyether urethane prepolymer, which is polypropylene glycol (molecular weight = approximately 1000) with 4,4'-diphenylmethane diisocyanate added to both molecular ends. Mixture (solids concentration = 37
%) Test-3 Primer: Cl-PP with chlorination degree of 32% (solid content = 45
%) Topcoat: A mixture of 100 parts by weight of acrylic adhesive-C and 1.0 parts by weight of isophorone diisocyanate (solid content concentration = 37%) Test-4 (Comparative Example-1) Basecoat: Cl- with a degree of chlorination of 2% PP (solid content = 10
%) Topcoat: (Test-1 topcoat) Test-5 (Comparative Example-2) Basecoat: Cl-PP with chlorination degree of 70% (solid content concentration = 10
%) Topcoat: (Test-1 topcoat) Test-6 (Comparative Example-3) Chloroprene rubber adhesive (manufactured by Konishi Co., Ltd., “G-
17”) only used.

[Second example]

As shown in FIG. 2, the molding of this embodiment includes a molding base material 1b made of vinyl chloride resin, a tape 4b made of 5x polyethylene foam, an undercoat 2 and a topcoat applied to the surface of the tape 4b. 3
It is made up of. The molding base material 1b is obtained by extrusion molding a vinyl chloride resin having a composition shown in Table 3 below at 170°C.

[Table] Next, in order to measure the adhesion between the molding base material 1b and the tape 4b, a test was conducted using the following method. Test method: Tape 4b made of 5x polyethylene foam
After applying primer 2 to the surface and air-drying it at room temperature for 30 minutes, top coat 3 was applied thereon, and the molding base material 1b made of vinyl chloride resin was laminated and heated at 100°C.
and dried for 2 minutes. Next, this molding was left at room temperature (25° C.) for 20 days, and then the shear strength was measured at a tensile rate of 30 mm/min, and the results shown in Table 4 were obtained. The compositions of the base coat 2 and top coat 3 used are as follows. (All organic solvents used were toluene/cyclohexane/ethyl acetate = 1/1/1
[Weight ratio]. ) Test-7 Primer: Cl-PP with chlorination degree of 34% (solid concentration = 30
%) Topcoat: A mixture consisting of 100 parts by weight of acrylic adhesive D and 1.0 parts by weight of polyester urethane prepolymer with tolylene diisocyanate added to both molecular ends of polybutylene adipate (molecular weight = approximately 2000) (solid content = 37%) Test-8 Primer: Cl-PP with chlorination degree of 43% (solid content = 60
%) Topcoat: A mixture of 100 parts by weight of acrylic adhesive A and 1.0 parts by weight of isophorone diisocyanate (solids concentration = 37%) Test-9 Basecoat: Cl-PP with a degree of chlorination of 60% (solids concentration = 60
%) Topcoat: Acrylic adhesive - 100 parts by weight of B, 4,
4′,4″-Triphenylmethane triisocyanate
Mixture consisting of 100 parts by weight (solid content concentration = 37%) Test-10 Only acrylic adhesive (manufactured by Mitsubishi Rayon Co., Ltd., "Dianal-882") was used.

[Table] * Material destruction From the above test results, it was found that by using the undercoat 2 and topcoat 3 of this example, the adhesion between the molding base material 1b and the tape 4b was significantly improved. . This molding can be attached to an automobile body or bumper by applying a commercially available acrylic adhesive or chloroprene rubber adhesive to the other side of the tape. In particular, when the tape is made of a polyolefin polymer, the undercoat and topcoat of the present invention may be applied. It should be noted that the present invention is not limited to the above embodiments, and for example, as shown in FIG. 3, the mall base 1c is made of a polyolefin polymer such as EPDM, and the tape 4c is also made of a polyolefin polymer such as polyethylene. In this case, a configuration may be adopted in which the undercoat 2 is applied to the back surface of the molding base material 1c and the surface of the tape 4c, and the topcoat 3 is applied between them. In addition, prior to applying the primer 2, the surface of the molding base material (or tape) made of polyolefin polymer is subjected to corona discharge treatment, plasma treatment, etc., so that the primer 2 and the molding base material (or tape) are bonded together. The adhesion between the two can be further strengthened. As an example, conditions for performing corona discharge treatment are shown below. Corona discharge treatment conditions: Power: 1KW Electrode: Knife type Electrode length: 300mm Electrode-base material spacing: 1.0mm Effects of the invention As detailed above, the molding has extremely strong adhesion between the molding base material and the tape. By attaching this to an adherend (automobile body or bumper),
It is less likely to peel off even after long-term use.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a molding according to a first embodiment, FIG. 2 is a cross-sectional view showing a molding according to a second embodiment, and FIG. 3 is a cross-sectional view showing a molding according to another example. 1a, 1b, 1c...Mall, 2...Undercoat,
4a, 4b, 4c...tape, 3...top coating agent.

Claims (1)

[Scope of Claims] 1. Consists of a molding base material and a tape attached to the back surface of the molding base material, and between the back surface of the molding base material and the tape, (a) an undercoat having a chlorination degree of 5 to 5; 60% chlorinated polyolefin is applied and formed, (b) an active hydrogen-containing acrylic adhesive is used as a topcoat.
Urethane prepolymer 0.007 per 100 parts by weight
~10 parts by weight or polyisocyanate 0.07~
A molding characterized by being formed by applying a mixture containing 2500 parts by weight. 2. The mall according to claim 1, wherein at least one of the mall base material and the tape is a polyolefin polymer.