JPH0144267B2 - - Google Patents

Abstract

PURPOSE:To provide a mounting structure having ahderence to a molding which comprises an adhered and a molding fixed thereto with a mixture of a particular silicone adhesive, an acryl adhesive contg. an active hydrogen, and a polyurethane. CONSTITUTION:A structure comprising an adhered and molding fixed thereto with the following adhesive is provided. The adhesive employed is a mixture of a silicone adhesive (a) prepd. by mixing 100pts.wt. polydimethylsiloxane having an MW of 5,000-10,000,000 with 30-300pts.wt. polysiloxane having an MW of 100-1,000,000 and represented by the formula (wherein R is a siloxane; and m/n=0.5-5/1), an acryl adhesive (b) contg. an active hydrogen, and a polyurethane and/or a polyisocyanate (c). This mounting structure may be used to mount a molding composed of a vinyl chloride resin, an ethylene- propylene-diene terpolymer (EPDM) or the like onto an automobile main frame. The mounting structure remarkably improves the adherence between the main frame and the molding.

Description

[Detailed description of the invention]

Object of the Invention (Field of Industrial Application) The present invention relates to a mounting structure for a molding attached to the body, bumper, etc. of an automobile. (Prior art) Automobile bodies and bumpers are made of synthetic resin or synthetic rubber, especially vinyl chloride resin, EPDM (ethylene-propylene-diene ternary copolymer rubber), EPM (ethylene-propylene copolymer rubber), etc. A molding made of polyolefin vulcanized rubber is attached. 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 the function of decoration is called a side protection molding. It is attached to the body via double-sided tape coated with adhesive. Therefore, the above-mentioned molding mounting structure has the advantage that the mounting work is easy, and since there is no need to drill holes in the body, there is also the advantage that rust does not occur. The above-mentioned double-sided tape may also be made of sponge, non-woven fabric, film, etc. formed into a thin plate of material such as acrylic rubber, polyethylene, or chloroprene rubber.
A base material such as paper is used. Further, as the adhesive, an acrylic adhesive such as butylene acrylate, butyl methacrylate, 2-ethylhexyl acrylate, or a chloroprene adhesive is generally used. (Problems to be Solved by the Invention) However, problems with the mold made of vinyl chloride resin include repeated contraction and expansion due to temperature differences between day and night, summer and winter, and low molecular weight molecules in the mold. Due to various factors such as shrinkage due to volatilization of compounds, and shrinkage due to plasticizers and stabilizers in the mold decomposing and becoming low molecular weight due to interaction with heat, light, moisture, etc., and these volatilizing into the air, It has been pointed out that peeling tends to occur between the double-sided tape and the molding or between the double-sided tape and the body. In addition, a problem with molds made of EPDM, EPM, etc. is that these polyolefin vulcanized rubbers do not contain polar groups in the main chain of their molecules, so paints, adhesives, etc.
It has been pointed out that even when an adhesive is applied, the adhesion of the resulting coating film is insufficient, and peeling is likely to occur between the double-sided tape and the molding, or between the double-sided tape and the body. As a result of repeated research into the mounting structure of the molding with the aim of solving the above-mentioned problems, the present inventor has developed a mold that has strong adhesion to the molding made of the above-mentioned vinyl chloride resin and polyolefin vulcanized rubber such as EPDM and EPM. They discovered an adhesive and arrived at the present invention. Structure of the Invention (Means for Solving Problems) The present invention provides a structure in which a molding is attached to an adherend using an adhesive, wherein the adhesive is (a) polydimethyl having a molecular weight of 50 to 10 million; 100 parts by weight of siloxane and general formula (wherein R is siloxane, and m/
Molecular weight 100 to 100 expressed as n=0.5 to 5/1)
(b) an acrylic adhesive containing active hydrogen; and (c) a polyurethane and/or polyisocyanate. It adopts a molding mounting structure. (Function) With the above means, the adhesion of the molding to the adherend is significantly improved compared to the stress caused by the expansion and contraction of the molding caused by the various factors mentioned above, thereby preventing the molding from peeling off from the adherend. (Example) Hereinafter, the composition of the adhesive used in the molding mounting structure of the present invention will be explained. (a)-1 The polydimethylsiloxane used in the present invention is a linear polymer with a molecular weight of 50 to 10 million, and preferably has a viscosity in the range of 100,000 to 500,000 cSt. Polydimethylsiloxane has a molecular weight of 5000
If the temperature is below, it will gradually show mold releasability,
On the other hand, when it exceeds 10 million, it gradually begins to exhibit rubber-like elasticity, and in any case, it no longer exhibits tackiness. (a)-2 General formula The polysiloxane represented by is a polymer having a network structure and a molecular weight of 1 million to 1 million, and has the following siloxane skeleton. At the end of and has an m/n ratio in the range of 0.5 to 5/1. Furthermore, it is also possible to use one in which a part of the above methyl group is substituted with a vinyl group or a phenyl group. When this m/n ratio is less than 0.5, the viscosity decreases,
Moreover, when it exceeds 5, the hardness gradually increases, and in any case, the adhesion strength decreases. The molecular weights of these polymers are determined using JASCO Corporation's FLC-A-700 (column: shodex-A-
80M) in tetrahydrofuran. Next, to produce a silicone adhesive, 30 parts by weight of the polysiloxane represented by the above general formula is added to 100 parts by weight of the above polydimethylsiloxane in an organic solvent.
It is sufficient to mix the polysiloxane in a proportion of ~300 parts by weight, but if the amount of polysiloxane is less than 30 parts by weight or more than 300 parts by weight, the adhesive strength will decrease. The organic solvents used during mixing are saturated hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; ethers such as dioxane and tetrahydrofuran; acetic acid such as ethyl acetate and propyl acetate. Ester: A solvent formed by one type of solvent or a mixture of two or more types appropriately selected from ketones such as acetone, cyclohexanone, and methyl ethyl ketone. Specific examples of the silicone adhesive having the above composition are shown below. Silicone adhesive A: 100 parts by weight of polydimethylsiloxane with a molecular weight of approximately 500,000 and the formula (In the formula, R is siloxane, the same applies hereinafter) and 150 parts by weight of polysiloxane with a molecular weight of approximately 100,000 and m/n = 1/2 are diluted and mixed with toluene so that the solid content becomes 40%. did. Silicone adhesive B: 100 parts by weight of polydimethylsiloxane with a molecular weight of approximately 50,000 and the formula 30 parts by weight of polysiloxane having a molecular weight of approximately 500,000 and m/n = 1/0.5 was diluted and mixed with toluene so that the solid content was 40%. Silicone adhesive C: Polydimethylsiloxane 100 with a molecular weight of approximately 10 million
Weight part and formula 300 parts by weight of a polysiloxane having a molecular weight of approximately 1 million and m/n = 1/5 expressed by the formula was diluted and mixed with toluene so that the solid content was 40%. Silicone adhesive D: 100 parts by weight of polydimethylsiloxane with a molecular weight of approximately 100,000 and the formula Contains 5.2 x 10 mol/g of vinyl group-containing polysiloxane with a molecular weight of approximately 100,000, and has the formula 100 parts by weight of polysiloxane with a molecular weight of approximately 500,000 and m/n = 1/1.9, and its solid content is 40%.
It was diluted and mixed with toluene so that (b) The active hydrogen-containing acrylic adhesive is one obtained by copolymerizing acrylic acid, methacrylic acid, or a mixture of two or more of these derivatives and the following active hydrogen compound in an 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 methacrylate, 2-hydroxyethyl methacrylate, 2-
In addition to 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 hydrogen-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) was 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). solids content 37%). 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 =
A mixed solvent consisting of toluene/cyclohexane/ethyl acetate = 1/1/1 (weight ratio) was added to 26-30) (solid content 37%). (c) Polyurethane is an adhesive polymer obtained by polymerizing polyol and isocyanate, then adding a chain extender and further polymerizing. In particular, a polymer containing an NCO group or an OH group at the end of the molecule obtained by polymerizing polyol and isocyanate so that the isocyanate is in excess in molar ratio, then adding a chain extension period and further performing the polymerization reaction, NCO group
Due to the polarity of the OH group, it exhibits high adhesion to polyolefin vulcanized rubber. The above polyol may be either a polyester polyol or a polyether polyol, and the polyol components of the polyester polyol include ethylene glycol, 1,2-propylene glycol, 1,4-butanediol,
Examples include 1,3-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-pentanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and trimethylolpropane. can. 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. In addition, as the isocyanate, 2,4-tolylene diisocyanate, hydrogenated 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hydrogenated 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene Diisocyanate, xylene diisocyanate, hydrogenated xylene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, etc., or 4,4′,4″-triphenylmethane triisocyanate, tris-
Multifunctional isocyanates such as (p-isocyanate phenyl)-thiophosphate can be exemplified. Furthermore, the isocyanate polymers listed above may be used in place of or in conjunction with the polyurethane. Specific examples of polyurethane having the above composition are shown below. Polyurethane A: 164 parts by weight of polypropylene glycol with a molecular weight of 2000 and 100 parts by weight of 4,4'-diphenylmethane diisocyanate were mixed in 1,1,1-trichloroethane/dimethylformamide so that the solid content of these was 35%. = Dissolved with a 100/60 mixed solvent.
Next, this solution was reacted in dry nitrogen gas at 80°C for 3 hours, and then 24.8 parts by weight of 1,6-hexanediol was added as a chain extender, and further reacted in dry nitrogen gas at 80°C for 3 hours. . Polyurethane B: 164 parts by weight of polyethylene adipate with a molecular weight of 2000 and 69.6 parts by weight of tolylene diisocyanate were mixed 1,1,1 so that the solid content of these was 35%.
-Trichloroethane/dimethylformamide=
Dissolved with a 100/60 mixed solvent. Next, this solution was reacted in dry nitrogen gas at 80°C for 3 hours, and then 1,4-butanediol was added as a chain extender.
Part by weight was added and further heated at 80℃ in dry nitrogen gas for 3 hours.
Allowed time to react. Polyurethane C: 200 parts by weight of polybutylene adipate with a molecular weight of 2000 and 56.5 parts by weight of xylene diisocyanate were mixed in 1, 1, 1 so that their solid content was 35%.
-Trichloroethane/dimethylformamide=
Dissolved with a 100/60 mixed solvent. Next, this solution was reacted in dry nitrogen gas at 80°C for 3 hours, and then 11.8 parts by weight of ethylene glycol was added as a chain extender, and further reacted in dry nitrogen gas at 80°C for 3 hours. Polyurethane D: 100 parts by weight of polybutylene adipate with a molecular weight of 1000 and polypropylene glycol with a molecular weight of 2000.
400 parts by weight and 450 parts by weight of 4,4'-diphenylmethane diisocyanate, the solid content of which is 35%.
1,1,1-trichloroethane/
It was dissolved in a mixed solvent of dimethylformamide = 100/60. This solution was then heated for 80 h in dry nitrogen gas.
After reacting at ℃ for 3 hours, 1,6
-180.8 parts by weight of hexanediol was added, and the mixture was further reacted at 80°C for 3 hours in dry nitrogen gas. Next, in order to produce the adhesive used in the present invention, the above-mentioned (a) silicone adhesive, (b) active hydrogen-containing acrylic adhesive, and (c) polyurethane and/or polyisocyanate are added to the organic Simply mix in a solvent. The preferred mixing ratio (in terms of solid content) of the active hydrogen-containing acrylic adhesive and polyurethane is that the former is
The latter is preferably 0.07 to 10 parts by weight, more preferably 0.007 to 3 parts by weight, per 100 parts by weight. Below 0.007 parts by weight, the adhesive strength decreases;
Even if more than 1 part by weight is added, it will not contribute to the improvement of adhesive strength.
Moreover, the pot life of the resulting adhesive is shortened. In addition, the degree to which polyisocyanate is used in place of polyurethane is 0.007 parts by weight of polyisocyanate per 100 parts by weight of the active hydrogen-containing acrylic adhesive.
~10 parts by weight, more preferably 0.007 to 3 parts by weight. If it is less than 0.007 parts by weight, the adhesive strength will decrease as in the case of polyurethane, while if it is added in excess of 10 parts by weight, it will not contribute to improving the adhesive strength, and furthermore, the pot life of the resulting adhesive will be shortened. In addition, when using a mixture of polyurethane and polyisocyanate, it may be mixed with the active hydrogen-containing acrylic adhesive according to the above ratio. Furthermore, it is preferable to mix the silicone adhesive in a proportion of 5 to 1900 parts by weight based on 100 parts by weight of the total amount of the mixture consisting of the active hydrogen-containing acrylic adhesive and polyurethane; if the proportion is outside this range, the adhesive force will decrease. . Next, specific examples of the adhesive used in the present invention are shown in Tables 1 to 5 below. (All parts in the table are parts by weight.)

【table】

【table】

【table】

【table】

[Table] Next, an example of a molding mounting structure using the above adhesives 1 to 5 will be described with reference to the drawings. In this embodiment, as shown in FIG. 1, a molding 2 manufactured by extrusion molding of vinyl chloride resin is attached to an automobile body, that is, an adherend 1 made of acrylic-coated steel plate, via a double-sided tape 6. It is being The double-sided tape 6 is composed of a base 5 made of 5x polyethylene foam, and an adhesive 3 and an adhesive 4 coated on both sides of the base 5. The adhesive 4 coated on the side of the molding 2 is a conventionally well-known chloroprene rubber. adhesive (manufactured by Konishi Co., Ltd., "G-17"), and the adhesive 3 coated on the adherend 1 side is the adhesive 1 described above. For Molding 2, a vinyl chloride resin having the composition shown in Table 6 below was extruded at 170°C.

[Table] In the above example, a well-known chloroprene-based adhesive was used on the molding side of the base material, but the mounting structure of the molding of the present invention is not limited to the above example, and instead of using a chloroprene-based adhesive. , a configuration using a well-known urethane adhesive, an acrylic adhesive, or any one of the adhesives 1 to 5 above may be adopted. Further, instead of the foamed polyethylene, foamed acrylic rubber, foamed urethane rubber, foamed chloroprene rubber, nonwoven fabric, film, paper, etc. can also be used as the base material of the double-sided tape. Next, in order to measure the adhesive strength of the adhesives 1 to 5, a test was conducted using the following method. Test method: Two molds made of vinyl chloride resin using the above example were prepared, adhesive-1 was applied to the back surfaces of the molds, and the molds were air-dried at room temperature for 30 minutes. Thereafter, the adhesive-coated surfaces of these molds were stacked together and left at room temperature for 3 days, after which a shear test was conducted at a tensile rate of 30 mm/min. In addition, similar tests were conducted using Adhesives 2 to 4 and adhesives with the following compositions (Comparative Examples 1 and 2) as comparative examples, and the results shown in Table 7 were obtained. Furthermore, these malls were placed in a constant temperature bath at 80℃ for 5 minutes.
The shear strength was measured after being left for a period of time to undergo thermal deterioration, and the results shown in Table 8 were obtained. Comparative Example 1 100 parts by weight of polydimethylsiloxane with a molecular weight of approximately 100,000 and the formula A silicone adhesive was prepared by diluting 5 parts by weight of a polysiloxane with a molecular weight of about 1 million and m/n=1/2 expressed by toluene so that the solid content was 40%. Comparative Example 2 100 parts by weight of polydimethylsiloxane with a molecular weight of approximately 100,000 and the formula 500 parts by weight of polysiloxane with a molecular weight of approximately 1 million and m/n = 1/2, whose solid content is 40%.
A silicone adhesive was prepared by diluting it with toluene to give the following.

【table】

[Table] From the above test results, it was found that the shear strength of Adhesives 1 to 5 was sufficient for use in a structure in which a molding made of vinyl chloride resin is attached to an automobile body. Note that the adhesives of Comparative Examples 1 and 2 had lower shear strength because the mixing ratio of polysiloxane to polydimethylsiloxane was not appropriate. Next, another example of a molding attachment structure using the above-mentioned adhesives 1 to 5 will be explained with reference to the drawings. In this example, as shown in FIG.
A molding 2 manufactured by extrusion molding EPDM is attached to an automobile body, that is, an adherend 1 made of acrylic-coated steel plate, via an adhesive 3 coated on the back surface of the molding 2. In addition, Mall 2 is EPDM with the composition shown in Table 9.
It was manufactured by extruding and then vulcanizing at 200°C for 5 minutes.

[Table] Next, in order to measure the adhesive strength of the adhesives 1 to 5, a test was conducted using the following method. Test method: Two molds made of EPDM used in the above examples were prepared, adhesive-1 was applied to the back surfaces of the molds, and the molds were air-dried at room temperature for 30 minutes. Thereafter, the adhesive-coated surfaces of these moldings were stacked together and left at room temperature for 3 days, after which a shear test was conducted at a tensile rate of 30 mm/min. In addition, adhesives 2 to 4 and as a comparative example, the acrylic adhesive 1 (comparative example 3) and a commercially available acrylic adhesive (manufactured by Mitsubishi Rayon Co., Ltd., "Dianaru-882", comparative example 4) were used. A similar test was conducted and the results shown in Table 10 were obtained. Furthermore, these malls were placed in a constant temperature bath at 80℃ for 5 minutes.
The shear strength was measured after being left for a period of time to undergo thermal deterioration, and the results shown in Table 11 were obtained.

【table】

【table】

[Table] From the above test results, it was found that the shear strength of Adhesives 1 to 5 was sufficient for use in a structure in which a molding made of EPDM is attached to an automobile body. In addition, the adhesive used in the present invention not only has strong adhesion, but also exhibits the excellent properties of silicone resin such as heat resistance, weather resistance, and corrosion resistance. The present invention is not limited to this, and can generally be embodied in a structure in which various synthetic resin materials are attached to metal or other adherends. Effects of the Invention As detailed above, the present invention is used when attaching a molding made of vinyl chloride resin, EPDM, etc. to an automobile body, and exhibits the effect of significantly improving the adhesion between the body and the molding. ,
This is an excellent invention as a molding mounting structure.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment in which the structure is such that a car body is used as the adherend and a molding is attached to the body, and FIG. 2 is a cross-sectional view showing another example. 1...Adherent, 2...Mall, 4...Adhesive.

Claims (1)

[Scope of Claims] 1. In a structure in which a molding is attached to an adherend using an adhesive, the adhesive comprises (a) 100 parts by weight of polydimethylsiloxane having a molecular weight of 50 to 10 million; (wherein R is siloxane, and m/n
(b) an active hydrogen-containing acrylic adhesive, and (c) a polyurethane. A molding mounting structure characterized in that it is a mixture of and/or polyisocyanate. 2. The molding mounting structure according to claim 1, wherein the molding is attached to an adherend via a double-sided tape coated with an adhesive. 3. The molding mounting structure according to claim 1, wherein the polyurethane is a polyester polyurethane containing an NCO group or an OH group at the end of the molecule. 4. The mold according to claim 1, wherein the silicone adhesive is mixed in a proportion of 5 to 1900 parts by weight based on 100 parts by weight of the active hydrogen-containing acrylic adhesive and polyurethane. mounting structure.