JP2003027012A - Method for bonding fiber-reinforced plastic molded article and its bonded matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a practical bonding method highly reliable enough to stably permit firm bonding of a glass fiber-reinforced polypropylene molded article, and a bonded matter. SOLUTION: The method for bonding a fiber-reinforced plastic molded article comprises a step (1) of treating the surface of the glass fiber-reinforced polypropylene molded article with flame, a step (2) of coating the surface with a material containing at least one selected from the group A consisting of a chlorinated polyolefin, a chlorinated-polyolefin-modified acrylic polyol and a carboxyl group-containing chlorinated polyolefin, a step (3) of coating the surface obtained by the step (2) with an isocyanate-based primer and a step (4) of coating the surface obtained by the step (3) with a material containing at least one selected from the group B consisting of an isocyanate rubber-based adhesive, a polyol isocyanate-based adhesive and an isocyanate-modified polymer adhesive. The bonded matter is also provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding method for bonding a glass fiber-reinforced polypropylene molded product and the bonded product.

[0002]

Molded articles using glass fiber reinforced polypropylene have excellent mechanical strength, light weight effect, water resistance, chemical resistance, rust resistance and high productivity, such as automobile undercovers and spare parts. Widely used in tire pans, battery trays, etc. However, there is a problem that the surface of the polypropylene film is poor in wettability and inferior in adhesiveness to an adherend. Japanese Unexamined Patent Publication No. 9-321221 discloses that the surface of a polypropylene film can be flame-treated to improve its wettability and printability with a printing ink. In addition, in WO 97/39878, a flame functions as a fuel substitute or an oxidant substitute and has an oxygen content of 10 to 50% other than carbon monoxide. When maintained by a fuel-oxidant mixture containing at least one compound selected from the group consisting of oxygen-nitrogen containing compounds,
There is a disclosure of a method that includes exposing a polymer support to a flame.

[0003]

Molded articles used in automobiles and parts used by assembling the molded articles are required to have particularly high reliability in terms of long-term reliability and the like. However, as described above, polypropylene has a drawback that it has poor adhesiveness to an adherend, and in a glass fiber reinforced polypropylene molded product, glass fibers are likely to be raised on the surface and the adhesiveness is remarkably poor. Is rarely used.

[0004] In the case of adhering and painting molded articles that are difficult to adhere, such as polypropylene molded articles, the above-mentioned flame treatment and surface modification technology of irradiating with ultraviolet rays have been proposed, but in these methods, the optimum condition width is extremely high. It was too narrow and not practical for obtaining a stable adhesive force. Further, even if a primer which easily adheres to polypropylene is applied and a means for adhering is used, stable adhesive force has not been obtained yet.

An object of the present invention is to provide a highly reliable and practical bonding method and a bonded product for stably and firmly bonding a glass fiber reinforced polypropylene molded product.

[0006]

According to the present invention, the surface of a glass fiber reinforced polypropylene molded article is surface-treated with a flame, a material that easily adheres to polypropylene is applied to the surface, and then the material is adhered to an adhesive. By applying an easy-to-use material and then applying an adhesive and adhering the adherend, it is possible to obtain a stable adhesive force even if the width of the optimum condition deviates slightly during flame treatment. Wide range of suitable conditions and excellent practicality. More specifically, the present invention resides in that the surface of a glass fiber reinforced polypropylene molded product is subjected to flame treatment, and then a material that easily adheres to polypropylene and a material that easily adheres to an adhesive are applied.

That is, the gist of the present invention is as follows. (I) A step (1) of treating the surface of a glass fiber reinforced polypropylene molded article with a flame, wherein the surface is composed of chlorinated polyolefin, chlorinated polyolefin-modified acrylic polyol and carboxyl group-containing chlorinated polyolefin A
A step (2) of applying a material containing at least one member selected from the group, a step (3) of applying an isocyanate primer to the surface obtained in the step (2), and the step (3)
Glass fiber reinforced including a step (4) of applying a material containing at least one member selected from Group B consisting of an isocyanate rubber adhesive, a polyol isocyanate adhesive and an isocyanate modified polymer adhesive to the surface obtained in This is a method for adhering polypropylene molded products. (II) Step (1) of treating the surface of the glass fiber reinforced polypropylene molded product with a flame, and at least one member selected from Group A consisting of chlorinated polyolefin, chlorinated polyolefin-modified acrylic polyol and carboxyl group-containing chlorinated polyolefin on the surface. A step (2) of applying a material containing the above, a step (5) of applying a material that easily adheres to an adhesive on the surface obtained in the step (2), and a surface obtained in the step (5), Expression [1]

[Equation 3] E _B = (L ₁ −L ₀ ) / L ₀ × 100 ... [1] [where E _B is the elongation (%), L ₀ is the distance between the marked lines before the test (mm), L ₁ indicates the distance (mm) between the marked lines at the time of cutting. The measurement conditions are in accordance with JIS K 6251, using a tensile tester, the distance between the measurement marks is 20 mm, the gripper moving speed is 200 mm / min., 20 ° C. ± 2 ° C., 65
It was measured at ± 10% RH. ] Elongation rate (E _B )
Is a method of adhering a glass fiber reinforced polypropylene molded article, which includes a step (6) of applying an adhesive in which is 200% ≦ E _B ≦ 700% (III) In the item (I) or (II), the glass fiber reinforced polypropylene molded article is a method for adhering a glass fiber reinforced polypropylene molded article which is a compression molded article. (IV) Step (1) of treating the surface of the glass fiber reinforced polypropylene molded article with a flame, and at least one member selected from the group A consisting of chlorinated polyolefin, chlorinated polyolefin-modified acrylic polyol and carboxyl group-containing chlorinated polyolefin on the surface. Step (5) of applying a material that easily adheres to the material adhesive including the above, 20 ° C. ± 2 ° C., 65 ± 1
When measured at 0% RH (according to JIS K 6251, using a tensile tester, the distance between the measuring marks is 20 mm, and the moving speed of the gripping tool is 200 mm / min.), The formula [1]

[Equation 4] E _B = (L ₁ −L ₀ ) / L ₀ × 100 [1] [where E _B is the elongation (%), L ₀ is the distance between the marked lines before the test (mm), L ₁ indicates the distance (mm) between the marked lines at the time of cutting. The measurement conditions are in accordance with JIS K 6251, using a tensile tester, the distance between the measurement marks is 20 mm, the gripper moving speed is 200 mm / min., 20 ° C. ± 2 ° C., 65
It was measured at ± 10% RH. ] Elongation rate (E _B )
A glass fiber reinforced polypropylene molded article adhesive formed by forming an adhesive in the order of 200% ≦ E _B ≦ 700%. Can be provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The glass fiber reinforced polypropylene used in the present invention is, for example, a sheet-shaped molding material obtained by impregnating polypropylene resin with 0.002 m to 1 m of glass fiber in an amount of 10 to 50% by weight at 180 to 230 ° C. A glass fiber reinforced polypropylene molded article can be provided by heating and melting, and charging it into a compression molding mold having a mold temperature of 40 to 100 ° C. and performing pressure compression molding for 15 to 300 seconds at a pressure of 5 to 20 MPa. . In addition to polypropylene, various components such as polyethylene may be added to the glass fiber reinforced polypropylene. This glass fiber reinforced polypropylene molded product has excellent mechanical strength, heat resistance, water resistance, and chemical resistance, and also has an optimal weight reduction effect especially for automobile parts.

In the present invention, the method of flame-treating the surface of the glass fiber reinforced polypropylene molded article uses a flame using a combustible gas such as propane gas or methane gas,
While maintaining a constant distance from the polypropylene molded product, the polypropylene product is allowed to pass through the surface at a constant rate to form an activated group such as a hydroxyl group or a carbonyl group on the surface of the polypropylene so that the surface does not melt. The conditions of the flame treatment include a mixing ratio of air and fuel, an effective distance from the burner, etc., but the optimum conditions of these conditions vary greatly depending on the burner, but the materials shown in the examples of the present invention are used. According to the above method, excellent adhesive force can be obtained even if the flame treatment condition is slightly deviated from the optimum condition of the burner used.

In the present invention, the material that easily adheres to polypropylene is not particularly limited as long as it can form a chemical bond with an activated group such as a hydroxyl group or a carbonyl group formed on the surface of the polypropylene. Not a thing. For example, generally commercially available as a primer for polypropylene, chlorinated polypropylene or chlorinated polyethylene dissolved in a solvent such as toluene or xylene, polypropylene having a polar group introduced, polypropylene coating, etc. Can be used. Specific examples thereof include chlorinated polypropylene, chlorinated polypropylene-modified acrylic polyol, and carboxyl group-containing chlorinated polyolefin. After applying a material that easily adheres to polypropylene, heat treatment may be performed if necessary.

In the present invention, it is preferable that the adhesive has an elongation rate equivalent to that of the glass fiber reinforced polypropylene molded article. Specifically, JIS K 625
Using a tensile tester, measure the dumbbell No. 3 type test piece specified in 1 above with a distance of 20 mm between the marked lines, a gripper moving speed of 200 mm / min., 20 ° C ± 2 ° C, 65 ± 1
It is preferable that the elongation percentage (E _B ) represented by the above formula [1] is 200% ≦ E _B ≦ 700% when measured at 0% RH. More preferably, 200% ≦ E _B ≦ 600%. As the tensile tester, a commercially available tester can be used. As the adhesive, for example, a urethane-based adhesive having a rubber-like property is preferable from the viewpoint of stress relaxation of the bonded portion. Other adhesives include epoxy adhesives, formaldehyde adhesives, polyvinyl acetate adhesives, polyvinyl alcohol adhesives, acrylic resin adhesives, cyanoacrylate adhesives, styrene resin adhesives, polyvinyl ether adhesives. , Vinyl chloride-vinyl acetate copolymer adhesives, rubber adhesives, graft polymer adhesives, block polymer adhesives, and the like, and the elongation percentages thereof are preferably 200% ≦ E _B ≦ 700%. . In this case, as a material that easily adheres to the adhesive, an additive such as a primer or a coupling agent is applied.

A primer having a very good compatibility with the urethane-based adhesive and excellent adhesion is applied to the surface of the glass fiber reinforced polypropylene molded article as a material which is easily adhered to the adhesive before the application of the adhesive. It is preferable. Examples of the above-mentioned primer include an isocyanate-based primer and a curable urethane-based primer. When the former is used, it is preferable to use a solution of diisocyanates diluted with methyl ethyl ketone, ethyl acetate or the like, which may contain an additive such as carbon black. When the latter is used, a two-component curable urethane-based primer composed of a combination of a polyol component and a polyisocyanate component is preferable. When a material that easily adheres to the adhesive or a primer for urethane adhesive is applied, it is desirable to apply the adhesive within 30 seconds to 8 hours after the application.

Examples of urethane-based adhesives include polyisocyanates or isocyanate rubber-based adhesives containing polyisocyanate and compounded rubber, polyol isocyanate-based adhesives, and isocyanate-modified polymer adhesives.
Either may be used. Further, the isocyanate rubber-based adhesive or the prepolymer adhesive may contain an appropriate amount of solvent. Further, these urethane adhesives may contain a urea bond, a buret bond, an allophanate bond, etc. in addition to the urethane bond. Further, these adhesives may contain a basic compound such as a tertiary amine, an organic tin compound, or a naphthenate as a catalyst.

The present invention will be described in detail with reference to examples. [Examples] FIG. 1 is a process chart from the flame treatment of the surface of a glass fiber reinforced polypropylene molded article of the present invention to the application of an adhesive. In FIG. 1, (a) the surface of the glass fiber reinforced polypropylene molded article 1 is flame-treated by using a gas burner 2 to form a flame-treated surface 3. (B)
A material 4 that easily adheres to polypropylene is applied to the surface of the flame-treated surface 3. (C) A material 5 that easily adheres to the adhesive is applied to the surface of the material 4 that easily adheres to the polypropylene.
(D) The adhesive 6 is applied to the surface of the material 5 that easily adheres to the adhesive.

In this example, GM40PP-RWT manufactured by Simarit Co., Ltd. was used as the glass fiber reinforced polypropylene.
A flat plate molded product produced by compression molding, and as a material that easily adheres to the polypropylene, Chemloch 459X (primer containing chlorinated polyolefin) manufactured by Road Far East Co., Ltd., Micron 300 manufactured by Cashew Co., Ltd.
0 (a paint containing chlorinated polyolefin), as an adhesive, Beta Seal U-216 manufactured by Dow Chemical Co., Ltd.
(Urethane adhesive, elongation 425%), U-413 (isocyanate primer) manufactured by Dow Chemical Co., Ltd. was used as a primer for the adhesive.

The elongation percentage of the adhesive was measured by the following method after making a test piece according to the test piece manufacturing process shown in FIG. << Test Piece Manufacturing Process >> (1) A release paper 10 (100 × 100 mm) is laid on a glass plate 9 (100 × 100 × 5 mm), and spacers 11 (100 × 5 × 2 mm) are placed on both sides. (2) The adhesive 6 is piled up on the release paper 10 in the area surrounded by the spacer 11 of (1) so that air bubbles do not enter, and the release paper 10 and the glass plate 9 are stacked and pressure-bonded in this order. . After the pressure bonding, the upper glass plate 9 is removed. (3) The adhesive layer (sheet) obtained in “above” is 20 ° C.
After standing (curing) for 7 days under the condition of ± 2 ° C. and 65 ± 10% RH, a punching test piece was prepared with a dumbbell-shaped No. 3 punching die. << Measurement Method of Elongation Rate >> (4) A marked line for measurement is clearly and accurately attached to the central portion of the parallel portion of each test piece obtained above. (5) The test piece immediately after punching obtained above was attached to a grip of a tensile tester so that a load was applied to the center of a dumbbell-shaped test piece, and the test piece was placed under a condition of 20 ° C ± 2 ° C and 65 ± 10% RH. Distance between lines is 20 mm, moving speed of grips;
The test machine was moved at 200 mm / min., The distance between the marked lines when the test piece was cut was measured, and the elongation (E _B ) was calculated by the following formula [1].

[Equation 5] E _B = (L ₁ −L ₀ ) / L ₀ × 100 ... [1] [where E _B is the elongation (%), L ₀ is the distance between the marked lines before the test (mm), L ₁ indicates the distance (mm) between the marked lines at the time of cutting. ] The calculated values were averaged and rounded to the nearest whole number (unit:%).

Since Micron 3000 is a coating material for polypropylene, it is baked after being applied at 60 ° C. for 30 minutes. The flame treatment of the glass fiber reinforced polypropylene molded product used a gas burner formed by burning propane gas.

Example 1 The glass fiber reinforced polypropylene GM40PP-RWT surface was flame-treated with a gas burner. The length of the flame is 200 mm, and the speed is 500 mm / s at a position 60 mm below the root of the gas burner.
Moved the molded product. Chemlock 459X is applied to the flame-treated surface of GM40PP-RWT, and U-41
3 was applied. On top of that, adhesive solid seal U-21
6 was applied.

Example 2 A glass fiber reinforced polypropylene GM40PP-RWT surface was flame-treated with a gas burner. The length of the flame is 200 mm, and the speed is 500 mm / s at a position 60 mm below the root of the gas burner.
Moved the molded product. Micron 3000 was applied to the flame-treated surface of GM40PP-RWT, and after heat treatment at 60 ° C. for 30 minutes, U-413 was applied. Further, an adhesive agent Betasil U-216 was applied thereon.

Comparative Example 1 U-413 was applied on the surface of glass fiber reinforced polypropylene GM40PP-RWT, and then adhesive solid seal U-216 was applied.

Comparative Example 2 The glass fiber reinforced polypropylene GM40PP-RWT surface was flame-treated with a gas burner. The length of the flame is 200 mm, and the speed is 500 mm / s at a position 60 mm below the root of the gas burner.
Moved the molded product. U-413 was applied to the flame-treated surface of GM40PP-RWT, and then adhesive solid seal U-216 was applied.

The glass fiber reinforced polypropylene molded article adhesives obtained in the above Examples and Comparative Examples were left for 72 hours and then subjected to a hand peeling test. The hand peeling test method will be described with reference to FIG. The tip of the adhesive sample 7 formed on one main surface of the glass fiber reinforced polypropylene molded product 1 is
While pulling in the direction of 80 degrees, a cut is made with a knife 8 between the adhesive sample 7 and the glass fiber reinforced polypropylene molded product 1, and this operation is repeated. The judgment of the result was performed by observing the fractured state at this time. If the adhesion is weak, it causes interfacial peeling. Table 1 shows the evaluation results of the hand peel test. The number of test pieces used for evaluation is 5 (n = 5).

[0023]

[Table 1]

The bonding methods of Examples 1 and 2 of the present invention did not cause interfacial peeling even at room temperature and 90 ° C. and were excellent in adhesive strength. Moreover, the elongation percentage of the adhesive used in Examples 1 and 2 of the present invention was 425%, and excellent adhesive strength could be obtained. Generally, the elongation of polypropylene is in the range of 200 to 700% (Sakurauchi; New edition plastic material reader, Industrial Research Committee, 1993), and the elongation of the adhesive is in the same range as that of polypropylene, that is, 20.
If 0% ≤ adhesive elongation (E _B ) ≤ 700%, deviation (stress) at the interface between the polypropylene molding and the adhesive
Can be minimized and interfacial peeling can be suppressed.
Therefore, the elongation percentage of the adhesive is preferably close to that of the polypropylene molded product, and more preferably the elongation percentage of the adhesive is the same as that of the polypropylene molded product.

[0025]

According to the present invention, when a glass fiber reinforced polypropylene molded product is bonded, the surface of the glass fiber reinforced polypropylene molded product is treated with a flame, and then a material that easily adheres to polypropylene is applied, and an adhesive is further applied. It is possible to provide a practical bonding method and a bonded product by which a glass fiber reinforced polypropylene molded product is stably and firmly bonded by applying a material that easily adheres to, and then applying and curing the adhesive.

[Brief description of drawings]

FIG. 1 is a process chart showing one embodiment of a method for adhering a glass fiber reinforced polypropylene molded product of the present invention.

FIG. 2 is a diagram illustrating a hand peeling test method used in the present invention.

FIG. 3 is a diagram showing a process for producing a test piece for measuring the elongation of the adhesive of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass fiber reinforced polypropylene molded product, 2 ... Gas burner, 3 ... Flame-treated surface, 4 ... Material easy to adhere to polypropylene, 5 ... Material easy to adhere to adhesive, 6 ... Adhesive, 7 ... Adhesive sample, 8 ... knife, 9 ... glass plate, 10
... Release paper, 11 ... Spacer.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09J 175/04 C09J 175/04 // B29K 23:00 B29K 23:00 105: 06 105: 06 C08L 23: 12 C08L 23:12 (72) Inventor Atsushi Ishikawa 1150 Gotomiya, Shimodate City, Ibaraki Prefecture Gotomiya Works, Hitachi Chemical Co., Ltd. F term (reference) 4F006 AA12 AB13 AB24 AB37 BA01 CA04 DA04 EA01 EA03 EA05 4F071 AA14B AA20B AA53 AA53A AA79A AG01 AG11 AG12 AG30 AH07 AH11 CB01 CD01 4F073 AA01 BA08 GA03 4F211 AA11 AB25 AD19 AD33 AD34 TA03 TH02 TH21 TH22 TN47 TN51 4J040 PA30 PA13 PA13 PA13 PA16 PA13 PA13 MB02 MA16 MA08 MA08 MA11 MA02 MA11

Claims (4)

[Claims] 1. A step (1) of treating the surface of a glass fiber reinforced polypropylene molded article with a flame, in which the surface is chlorinated polyolefin, chlorinated polyolefin modified acrylic polyol and carboxyl group-containing chlorinated polyolefin. Step (2) of applying a material containing at least one or more kinds, step (3) of applying an isocyanate primer to the surface obtained in the step (2), and isocyanate rubber to the surface obtained in the step (3) Adhesive,
A method for adhering a glass fiber reinforced polypropylene molded article, which comprises a step (4) of applying a material containing at least one or more of Group B consisting of a polyol isocyanate-based adhesive and an isocyanate-modified polymer adhesive. 2. A step (1) of treating the surface of a glass fiber reinforced polypropylene molded article with a flame, in which the surface is chlorinated polyolefin, a chlorinated polyolefin-modified acrylic polyol and a carboxyl group-containing chlorinated polyolefin. A step (2) of applying a material containing at least one or more kinds, a step (5) of applying a material that easily adheres to an adhesive on the surface obtained in the step (2), and the step (5)
[1] [Equation 1] E _B = (L ₁ −L ₀ ) / L ₀ × 100 ... [1] [where E _B is the elongation (%) and L ₀ is the test value] The distance (mm) between the preceding marked lines and L ₁ indicate the distance (mm) between the marked lines at the time of cutting. The measurement conditions are in accordance with JIS K 6251, using a tensile tester, the distance between the measurement marks is 20 mm, the gripper moving speed is 200 mm / min., 20 ° C. ± 2 ° C., 65
It was measured at ± 10% RH. ] Elongation rate (E _B )
The method for adhering a glass fiber reinforced polypropylene molded article, which comprises the step (6) of applying an adhesive in which 200% ≦ E _B ≦ 700%. 3. The method for adhering a glass fiber reinforced polypropylene molded article according to claim 1, wherein the glass fiber reinforced polypropylene molded article is a compression molded article. 4. A step (1) of treating the surface of a glass fiber reinforced polypropylene molded article with a flame, wherein at least the group A consisting of chlorinated polyolefin, chlorinated polyolefin-modified acrylic polyol and carboxyl group-containing chlorinated polyolefin. Step (5) of applying a material that easily adheres to a material adhesive containing one or more kinds, equation [1] ## EQU2 ## E _B = (L ₁ -L ₀ ) / L ₀ × 100 ... [1] [equation among, E _B is the elongation (%), _{L 0} is the distance between the marked lines before the test (mm), _{L 1} represents a distance (mm) between bench marks at the time of cutting. The measurement conditions are in accordance with JIS K 6251, using a tensile tester, the distance between the measurement marks is 20 mm, the gripper moving speed is 200 mm / min., 20 ° C. ± 2 ° C., 65
It was measured at ± 10% RH. ] Elongation rate (E _B )
Of 200% ≦ E _B ≦ 700% in order, and a glass fiber reinforced polypropylene molded article adhesive article.