JPS62295982A - Molding mounting structure - 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 mounted on 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 or E.
PDM (ethylene-propylene-diene ternary copolymer rubber), EPM (ethylene-propylene copolymer rubber)
A molding made of polyolefin vulcanized rubber such as

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., as well as decoration, is called a side protection molding. is attached to the body using double-sided tape.

Therefore, the molding mounting structure described above has the advantage that the mounting work is easy, and since there is no need to make holes in the body, there is also the advantage that rust does not occur.

Further, the above-mentioned double-sided tape uses a base material such as a sponge made of a material such as acrylic rubber, polyethylene, or chloroprene rubber formed into a thin plate, or a nonwoven fabric, film, or paper.

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. Double-sided tapes are affected by various factors such as shrinkage due to volatilization of compounds, and shrinkage due to plasticizers and stabilizers in the molding decomposing and becoming low molecular due to interaction with heat, light, moisture, etc., and shrinkage due to these volatilizing in the air. It has been pointed out that peeling is likely to occur between the 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, pressure-sensitive adhesives, etc. It has been pointed out that even when applied, the adhesion of the resulting coating 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 on the mounting structure of moldings with the aim of solving the above problems, the inventors have found that the above-mentioned vinyl chloride resin and E
We discovered an adhesive that has strong adhesion to molds made of polyolefin vulcanized rubber such as PDM and EPM.
This has led to 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, in which the adhesive has a +al molecule f
f15000~10 million polydimethylsiloxane 1
00 parts by weight, -a formula (wherein R is siloxane, m/n =
('b) an active hydrogen-containing acrylic adhesive, and fc) It employs a molding attachment structure characterized by being made of a mixture of polyurethane and/or polyisocyanate.

(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.

(al-1 The polydimethylsiloxane used in the present invention has a molecule of 1
It is a linear polymer having a viscosity of 15,000 to 10,000,000 cSt, preferably a viscosity of 100,000 to 50,000 cSt.

When the molecular weight of polydimethylsiloxane becomes 5,000 or less, it gradually begins to exhibit mold releasability, while when it exceeds 10 million, it gradually begins to exhibit rubber-like elasticity, so in either case it no longer exhibits tackiness. .

al-2 The polysiloxane represented by the general formula is a polymer having a network structure and a molecular weight of 1 million to 1 million, containing the following siloxane skeleton 1°CH:lSI - ^H3 and having an m/n ratio. It is a polymer 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 the m/n ratio is less than 0.5, the viscosity decreases, and when it exceeds 5, the hardness gradually increases, and in either case, the adhesive strength decreases.

The molecular weight of these polymers is based on FLC manufactured by JASCO Corporation.
-A-700 (column: shodex-A-80M)
The molecular weight is measured in tetrahydrofuran using styrene equivalent.

Next, in order to produce a silicone adhesive, it is sufficient to mix 30 to 300 parts by weight of polysiloxane represented by the general formula to 100 parts by weight of polydimethylsiloxane in an organic solvent. If the amount of siloxane is less than 30 parts by weight or more than 300 parts by weight, the adhesive strength will decrease.

Organic solvents used during mixing include 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 about 500,000 and polysiloxane 150 with a molecular weight of about 100,000 and m / n = 1 / 2 represented by the formula (wherein R is siloxane, the same applies hereinafter) Parts by weight were diluted and mixed with toluene so that the solid content was 40%.

Silicone adhesive-B: 100 parts by weight of polydimethylsiloxane with a molecular weight of approximately 50,000 and a molecular weight of approximately 500,000 expressed by the formula, m/n = 1/
0.5 and 30 parts by weight of polysiloxane were diluted and mixed with toluene so that the solid content was 40%.

Silicone adhesive - 〇2 100 parts by weight of polydimethylsiloxane with a molecular weight of about 10 million and a molecular weight of about 1 million expressed by the formula, m / n = 1 /
300 parts by weight of polysiloxane No. 5 were diluted and mixed with toluene so that the solid content was 40%.

Silicone adhesive-D: Contains 100 parts by weight of polydimethylsiloxane with a molecular weight of approximately 10,000, and 5.2 x 10 mol/g of vinyl group-containing polysiloxane with a molecular weight of approximately 100,000 represented by the formula, and has a molecular weight represented by the formula About 500,000 yen, m/n=1/1.9 polysiloxane (100 weight) was diluted and mixed with toluene so that the solid content was 40%.

('b) Active hydrogen-containing acrylic adhesive is a product obtained by copolymerizing acrylic acid, methacrylic acid, or a mixture of two or more of these derivatives and the following active hydrogen compounds in an organic solvent. .

Specifically, the above acrylic acid derivatives include methyl acrylate, ethyl acrylate, n-butyl acrylate, 1
Examples include so-butyl acrylate, 2-ethylhexyl acrylate, isodecyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycidyl acrylate, and dimethylaminoethyl acrylate.

In addition, methacrylic acid derivatives include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate,
Examples include 1so-butyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl methacrylate, and dimethylaminoethyl methacrylate.

Furthermore, active hydrogen compounds include the above-mentioned acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, etc., as well as maleic acid, maleic anhydride, and fumaric acid. ,
Examples include organic acids such as citraconic acid, citraconic anhydride, itaconic acid, and itaconic anhydride.

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). (37% solids).

Acrylic adhesive-C: Toluene/cyclohexane/ethyl acetate = 1/1/1 (
A mixed solvent consisting of (weight ratio) was added (solid content 37%).

Acrylic adhesive-D: Copolymer of n-butyl acrylate and 2-hydroxypropyl methacrylate (hydroxyl value = 26 to 30) toluene/cyclohexane/ethyl acetate = 1/1/1
Added a mixed solvent consisting of (weight ratio) (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 molecular end obtained by polymerizing a polyol and an isocyanate so that the isocyanate is in excess in molar ratio, then adding a chain extender and further performing a polymerization reaction,
It exhibits high adhesion to polyolefin vulcanized rubber due to the polarity of the CO group and OH group.

The 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, and 1,4-propylene glycol.
-butanediol, 1,3-butanediol, 2,3-
Butanediol, 1,5-bentanediol, 1,6-
Examples include bentanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and trinotyrolpropane.

Examples of organic acid components include dicarboxylic acids such as succinic acid, phthalic acid, phthalic anhydride, isophthalic acid, maleic acid, 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.

Examples of the isocyanate include 2,4-1-lylene diisocyanate, hydrogenated 2,4-tolylene diisocyanate, 4,4"-diphenylmethane diisocyanate, hydrogenated 4,4"-diphenylmethane diisocyanate, 1.
Diisocyanates such as 5-naphthalene diisocyanate, xylene diisocyanate, hydrogenated xylene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, or 4.4', 4"
-Triphenylmethane triisocyanate, tris-
Examples include polyfunctional isocyanates such as (p-isocyanate phenyl)-thiophosphate.

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 of 12,000 molecules and 1 part of 4,4'-diphenylmethane diisocyanate
00 parts by weight so that the solid content of these is 35%,
1, 1, 1. -) Dissolved in a mixed solvent of dichloroethane/dimethylformamide = 100/60. Next, this solution was reacted in dry nitrogen gas at 80°C for 13 hours, and then 24.8 parts by weight of 1,6-hexanediol was added as a chain extender, and the solution was further reacted in dry nitrogen gas at 80°C for 13 hours. .

Polyurethane-B: 164 parts by weight of polyethylene adipate with a molecular fi of 2000 and 69.6 parts by weight of tolylene diisocyanate were mixed so that their solid content was 35% (1.1.1-)
Dichloroethane/dimethylformamide = 100/60
It was dissolved in a mixed solvent of Next, this solution was reacted in dry nitrogen gas at 80°C for 3 hours, and then 1
, 18.9 parts by weight of 4-butanediol were added thereto, and the mixture was further reacted at 80° C. for 3 hours in dry nitrogen gas.

Polyurethane - 200 parts by weight of polybutylene adipate with a molecular weight of 2000 and 56.5 parts by weight of xylene diisocyanate were mixed so that the solid content of these was 35%, 1.1.1-trichloroethane/dimethylformamide = 100/ It was dissolved in a mixed solvent of 60%. 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 fi of 1000 and polypropylene gellicol 4 with a molecular weight of 2000.
00 parts by weight of 4.4°-diphenylmethane diisocyanate and 450 parts by weight of 4.4°-diphenylmethane diisocyanate were dissolved in a mixed solvent of LL, 1-trichloroethane/dimethylformamide = 100/60 so that their solid content was 35%. Next, this solution was reacted in dry nitrogen gas at 80°C for 3 hours, and then 1,6-hexanediol 180% was added as a chain extender.
．． Add 8 parts by weight and further add 80'C1 in dry nitrogen gas.
The reaction was allowed to proceed for 3 hours.

Next, to produce the adhesive used in the present invention, the above-mentioned (al silicone adhesive, fbl active hydrogen-containing acrylic adhesive, and FC+
It is only necessary to mix the polyurethane and/or polyisocyanate in the organic solvent.

The preferred mixing ratio (in terms of solid content) of the active hydrogen-containing acrylic adhesive and polyurethane is 0.007 to 10 parts by weight, more preferably 0.007 to 10 parts by weight of the latter to 100 parts by weight of the former.
．． 007 to 3 parts by weight.

If the amount is less than 0,007 parts by weight, the adhesive strength will decrease, and if it is added more than 10 parts by weight, it will not contribute to improving the adhesive strength, and the usable life of the resulting adhesive will be shortened.

In addition, the degree of use of polyisocyanate instead of polyurethane is 100f for active hydrogen-containing acrylic adhesive! The amount of polyisocyanate is 0.007 to 10 parts by weight, more preferably 0.007 to 3 parts by weight.

If it is less than 0,007 parts by weight, as in the case of polyurethane,
On the other hand, adding 10 parts by weight or more does not contribute to improving the adhesive strength, and furthermore, the pot life of the resulting adhesive is shortened.

In addition, even when using a polyurethane and polyisocyanate combination, it is not necessary to mix it with the active hydrogen-containing acrylic adhesive according to the above ratio.

Further, the silicone adhesive is preferably mixed 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 Table 1 below.
~5. (All parts in the table are parts by weight.) Table-1 (Adhesive-1) Table-2 (Adhesive-2) Table-3 (Adhesive-3) Table-4 (Adhesive-4) Table 5 (Adhesives 5) 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 a steel plate coated with acrylic, via a double-sided tape 6. installed.

The double-sided tape 6 is made up of a base material 5 made of 5x polyethylene foam, and an adhesive 3 and an adhesive 4 coated on both sides of the base material 5. The adhesive 4 coated on the side of the molding 2 is made of conventionally well-known chloroprene. Rubber adhesive (manufactured by Konishi Co., Ltd., r
G-17J), and the adhesive 3 coated on the adherend 1 side is the adhesive 1 described above. The mold 2 used was made by extrusion molding a vinyl chloride resin having a composition shown in Table 6 below at 170°C.

In the above embodiment, 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-mentioned embodiment, and instead of the chloroprene-based adhesive, a well-known chloroprene-based adhesive was used. A structure using a 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, 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 moldings were placed on top of each other 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.
The results shown in Table 7 were obtained.

Furthermore, these moldings were left in a constant temperature bath at 80° C. for 5 hours to thermally deteriorate, and then the shear strength was measured, and the results shown in Table 8 were obtained.

Comparative Example-1 100 parts by weight of polydimethylsiloxane with a molecular weight of about 100,000 and 5 parts by weight of polysiloxane with a molecular weight of about 1 million and m/n = 1/2, represented by 2, were mixed to have a solid content of 40%. A silicone adhesive was prepared by diluting it with toluene.

Comparative Example-2 100 parts by weight of polydimethylsiloxane with a molecular weight of about 100,000 and 500 parts by weight of polysiloxane with a molecular weight of about 1,000,000 and m/n = 1/2 expressed by the formula were mixed to a solid content of 40%. A silicone adhesive was prepared by diluting it with toluene.

Table 7 Table 8 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 mounting structure using the above adhesives-1 to 5 will be explained with reference to the drawings.

In this embodiment, as shown in FIG. 2, a molding 2 manufactured by extrusion molding EPDM is attached to an automobile body, that is, a steel plate coated with acrylic paint, through an adhesive 3 coated on the back surface of the molding 2. It is attached to the body 1.

The molding 2 was produced by extruding EPDM having the composition shown in Table 9 and then vulcanizing it at 200° C. for 5 minutes.

Table 9 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 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 min/min.

In addition, using Adhesives-2 to 4 and as a comparative example, the above-mentioned acrylic adhesive-1 (Comparative Example-3) and a commercially available acrylic adhesive (manufactured by Mitsubishi Rayon Co., Ltd., "Dianal-882", Comparative Example-4) were used. A similar test was conducted, and the results shown in Table 10 were obtained.

Furthermore, the shear strength of these moldings was measured after leaving them in a thermostat at 80°C for 5 hours for thermal deterioration. The strength is E
It was found that the molding made of PDM has sufficient strength when used in a structure for attaching it 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 any particular structure, 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 exhibits the effect of significantly improving the adhesion between the body and the molding when it is used when attaching a molding made of vinyl chloride resin, EPDM, etc. to an automobile body. This is an excellent invention as a molding mounting structure.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the structure in which a car body is used as an adherend and a molding is attached to this. FIG. 1. Adherent, 2. Molding, 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 contains (a) 100 parts by weight of polydimethylsiloxane with a molecular weight of 5,000 to 10 million, and a general formula ▲ mathematical formula, chemical formula , tables, etc. ▼ (In the formula, R is siloxane, and m/n = 0.5 to 5/1) Mixing a polysiloxane with a molecular weight of 1 to 1 million and 30 to 300 mold parts A molding attachment structure characterized in that it is a mixture of a silicone adhesive formed by: (b) an active hydrogen-containing acrylic adhesive; and (c) polyurethane 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 polyurethane has an NCO group or an OH group at the molecular end.
The molding mounting structure according to claim 1, wherein the molding mounting structure is made of polyester polyurethane containing a polyester polyurethane group. 4. The silicone adhesive is used in an amount of 5 to 1 part by weight per 100 parts by weight of the active hydrogen-containing acrylic adhesive and polyurethane.
The molding mounting structure according to claim 1, characterized in that the mixture is mixed at a ratio of 900 parts by weight.