JP3049178B2 - Laminate and its manufacture - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate in which a polyamide-based thermoplastic resin layer is laminated on a surface of a fluorine-based resin layer and a method for producing the same.

[0002]

2. Description of the Related Art There are various types of laminates obtained by laminating a fluorine-based resin having excellent corrosion resistance to chemicals and gasoline, and a polyamide-based thermoplastic resin having excellent properties such as abrasion resistance. It is used for applications. As such a laminated body, for example, a two-layer automotive fuel pipe in which a fluorine-based resin layer is formed as an inner layer that is in direct contact with a fuel such as gasoline and an outer layer made of a polyamide-based thermoplastic resin is formed on the outer periphery thereof Hoses. At the time of manufacturing this laminate, an adhesive treatment is usually performed using a resin adhesive such as a urethane adhesive or an epoxy adhesive. Before this adhesive treatment, a special adhesive pretreatment is performed. This is because the fluororesin is difficult to adhere to, so that it is difficult to obtain a sufficient adhesive strength only by performing an adhesive treatment using the above adhesive, and it is difficult to obtain a practically usable laminate. . As a special pretreatment method for bonding, there is a method of modifying the surface of a fluororesin with a metal sodium complex solution. This pretreatment method is a method in which a fluorine-based resin is immersed in a complex solution of metallic sodium, pulled up, washed and dried. By performing this treatment, the fluorine-based resin and the polyamide-based thermoplastic resin can be firmly bonded to each other using the above-mentioned adhesive. However, the above method has a disadvantage that the whole manufacturing process is long and complicated since many processes such as immersion and cleaning are required. Further, the metal sodium complex solution and the adhesive have a problem in safety for the human body. Furthermore, since the waste liquid generated at the time of the above-mentioned washing is also harmful, a large-scale facility for treating the waste liquid is required, resulting in a problem that the cost is increased.

[0003]

On the other hand, as a pretreatment method other than the above, a corona discharge treatment method has been proposed and partially implemented. This pretreatment method is a method in which the number of steps is small and there is no problem in safety as compared with the method using the above-mentioned metal sodium complex solution. In addition, since special equipment and devices required for glow discharge processing and the like are not required, this processing method can reduce equipment costs. However, this corona discharge treatment method has a disadvantage that the effect of the pre-adhesion treatment is lower than the method using a metal sodium complex solution. Therefore, the laminate produced by this method has a problem in practicality due to low adhesive strength.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a low-cost laminate having excellent adhesive strength and a method of producing a laminate having excellent safety and high production efficiency. And

[0005]

In order to achieve the above-mentioned object, the present invention provides a laminate comprising a fluorine-based resin layer and a polyamide-based thermoplastic resin layer laminated on the surface thereof. The first aspect is a laminate in which the laminated surface of the layers is formed on a rough surface, and the aminosilane-based coupling agent-treated layer is formed on the rough surface, and a polyamide-based thermoplastic resin is formed on the surface of the fluororesin layer. A method for producing a laminate in which layers are laminated, wherein a step of performing a corona discharge treatment on the surface of the fluororesin layer and a treatment layer formed by treating the surface of the discharge-treated fluororesin layer with an aminosilane coupling agent And bonding the two using the heat melting, with the surface of the fluorine-based resin layer on which the aminosilane-based coupling agent-treated layer is formed and the surface of the polyamide-based thermoplastic resin layer facing each other. The preparation of the stack of a degree to the second aspect.

[0006]

In other words, the present inventors have conducted a series of studies focusing on the surface treatment of the fluororesin layer in order to achieve the above object. As a result, when the surface of the fluorine-based resin layer is formed on a rough surface, and a treatment layer with an aminosilane-based coupling agent is formed on the rough surface, a polyamide-based thermoplastic resin layer formed on the rough surface is laminated. At the contact surface of both,
It has been found out that the anchoring effect occurs due to the state of being bitten into the concave portion of the rough surface, and that the affinity between the two layers is significantly improved. The inventors have found that the laminate obtained by performing the above two treatments has excellent adhesive strength without using an adhesive, and have reached the present invention. Further, the surface roughening treatment of the fluorine resin layer surface,
It can be carried out by a corona discharge treatment with a small number of steps and no problem in safety. Further, treatment with an aminosilane-based coupling agent is easy, and there is no problem in safety. Therefore, according to the present invention, excellent adhesive strength can be imparted to the laminate without using an adhesive, and excellent safety and high productivity can be realized in the production thereof.

Next, the present invention will be described in detail.

The laminate of the present invention can be produced by using a fluorine-based resin and a polyamide-based thermoplastic resin, for example, by performing a corona discharge treatment in the atmosphere and a treatment with an aminosilane-based coupling agent. it can.

As the above-mentioned fluororesin, copolymers of ethylene and tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (CTFE), copolymers of ethylene and chlorotrifluoroethylene (ECTFE), copolymer of hexafluoropropylene and tetrafluoroethylene (FEP), fluorinated alkoxyethylene resin (PF
A), polytetrafluoroethylene (PTFE) and the like. Among them, it is preferable to use ETFE.

A filler can be added to the above-mentioned fluororesin for the purpose of improving physical properties. Such fillers include titanium oxide, barium sulfate, calcium carbonate, silica, carbon black, magnesium silicate, aluminum silicate, zinc oxide, alumina, calcium sulfate, aluminum sulfate, calcium hydroxide,
Examples include aluminum hydroxide, talc, molybdenum dioxide, whiskers, short fibers, graphite, metal powder, silica sand, pumice powder, slate powder, mica powder, asbestos, glass spheres and the like. The mixing ratio of this filler is usually 100
It is set in the range of 0 to 30 parts by weight (hereinafter abbreviated as "part").

The polyamide-based thermoplastic resin is not particularly limited as long as it can be melted by heating, but nylon 6, nylon 66, nylon 11, nylon 12 having excellent properties such as abrasion resistance. It is preferable to use such as. These may be used alone or in combination of two or more.

A plasticizer may be added to the polyamide-based thermoplastic resin in order to improve processing characteristics and flexibility. Examples of the plasticizer include sulfonamides and oxybenzoic esters. The compounding ratio of this plasticizer is usually 10%.
It is set in the range of 0 to 20 parts for 0 part. Further, a filler used for a fluorine-based resin can be blended.

The aminosilane-based coupling agent used in the above-mentioned aminosilane-based coupling agent treatment includes those represented by the following general formula (1).

[0014]

Embedded image

Specific examples of such an aminosilane-based coupling agent include γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, and N-β- (amino Ethyl)-
γ-aminopropylmethyldimethoxysilane, γ-ureidopropyltriethoxysilane and the like. These may be used alone or as a mixture of two or more. Further, an additive such as phenol may be blended and used as a mixture mainly composed of the aminosilane-based coupling agent.

The laminate of the present invention is produced by using the above-mentioned raw materials by the following two processes, ie, the corona discharge treatment and the aminosilane-based coupling agent treatment.

First, a corona discharge treatment in the air using a high-frequency power supply is performed on the surface of the fluororesin. That is, first, as shown in FIG. 2, the film-like fluororesin 10 is placed in the processing chamber 7. Then, a frequency in the range of 20 to 40 kHz, 0.2
At an output in the range of ２０20 kW, a pre-adhesion treatment is performed by applying a voltage to the electrodes 8 and 9 to generate corona discharge. The treatment time is appropriately determined depending on the type or size of the fluororesin, and is usually set in the range of 1 to 60 seconds. In the figure, reference numeral 11 denotes a transformer.

Next, the surface of the fluororesin that has been subjected to the corona discharge treatment is treated with an aminosilane coupling agent. That is, the aminosilane-based coupling agent represented by the general formula (1) is dissolved in a solvent. Examples of the solvent include methanol. Then, this solution is applied to the surface of the fluororesin which has been subjected to the corona discharge treatment. The coating method is not particularly limited, and examples thereof include a commonly used dipping method, spraying method, and roll coating method. Among them, a spray method suitable for continuous production is preferable. Then, the aminosilane-based coupling agent-treated layer can be formed on the surface of the fluororesin by drying the applied aminosilane-based coupling agent.

On the other hand, a film-form polyamide thermoplastic resin is prepared, and one surface thereof is heated and melted. The conditions for the heating and melting are appropriately determined according to the melting point of the polyamide-based thermoplastic resin. Next, the above-mentioned discharge treatment is performed, and the fluorine-based resin on which the aminosilane-based coupling agent-treated layer is formed, and the polyamide-based thermoplastic resin that is subjected to heat-melting treatment, in a state where the treated surfaces are in contact with each other. By cooling to room temperature while pressing with a press under the conditions of a pressure of 0.1 to 30 kgf / cm ² and a time of 0.5 to 10 minutes, a fluorine-based resin layer 10 and a polyamide-based resin as shown in FIG. A laminate composed of the thermoplastic resin layer 15 can be manufactured. In the drawing, reference numeral 16 denotes an aminosilane-based coupling agent-treated layer.

As described above, by performing the corona discharge treatment, the surface of the fluorine-based resin is roughened, and the polyamide-based thermoplastic resin that has been melted by heating is infiltrated into the roughened surface. It has an effect. Further, by forming a treatment layer with the aminosilane-based coupling agent, the amino group in the coupling agent molecule has an affinity for the polyamide-based thermoplastic resin, and the Si—O structure in the molecule has a fluorine-containing structure. In order to show the affinity for the system resin, the affinity between the fluorine resin and the polyamide thermoplastic resin is significantly increased, and even without using an adhesive,
Both can be bonded with high strength. in this way,
By combining the surface roughening treatment by corona discharge treatment and the improvement in affinity by the aminosilane-based coupling agent, it is possible to produce a laminate having excellent adhesive strength without using an adhesive. This is the most important feature of the present invention.

The above-described corona discharge treatment, aminosilane-based coupling agent treatment, and heat melting treatment can be performed continuously by the following procedure. That is, first, after corona discharge treatment of the fluororesin surface,
An aminosilane-based coupling agent treatment is performed, and then a polyamide-based thermoplastic resin is placed on the above surface, melted by heating, immediately pressed under the above conditions, and cooled to room temperature.
In this way, it is possible to continuously manufacture a laminate.

Further, the above-described manufacturing method has been described with reference to a method of manufacturing a sheet-like laminate, but the present invention is not limited to this, and the present invention can be applied to other laminates such as a hose-like laminate. Is possible. For example, after the corona discharge treatment is performed on the outer peripheral surface of the cylindrical fluorine-based resin, an aminosilane-based coupling agent treatment is performed, and a polyamide-based thermoplastic resin is continuously extruded on the outer peripheral surface. Thus, a hose-like laminate can be manufactured according to the present invention.

[0023]

As described above, the laminate of the present invention is a laminate in which a polyamide-based thermoplastic resin layer is laminated on the surface of a fluorine-based resin layer, and the laminate surface of the above-mentioned fluorine-based resin layer is laminated. Is formed on a rough surface, and an aminosilane-based coupling agent-treated layer is formed on the rough surface. That is, since the polyamide-based thermoplastic resin layer is bonded to the roughened surface of the fluororesin layer in a state in which it is cut into the concave portion of the rough surface,
In addition to the high anchoring effect, the affinity between the fluorine-based resin layer and the polyamide-based thermoplastic resin layer is significantly increased by the aminosilane-based coupling agent-treated layer. As a result, the obtained laminate has excellent adhesive strength without using an adhesive. In addition, since no adhesive is used and no metal sodium complex solution is required, there is no problem in safety, and special equipment such as waste liquid treatment equipment is not required.
Therefore, it is possible to keep the equipment cost low.
In addition, in the present invention, the surface roughening of the fluororesin,
For example, it can be performed simply and continuously by a method such as corona discharge treatment in the atmosphere. In addition, aminosilane-based coupling agent treatment and heat melting treatment are also simple,
In addition, since continuous processing can be performed, improvement in manufacturing efficiency of the stacked body can be realized. Therefore, if the present invention is applied to, for example, a method of manufacturing a hose for an automobile fuel pipe having a laminated structure, a hose having excellent adhesive strength and corrosion resistance can be provided at a low price.

Next, examples will be described together with comparative examples.

[0025]

Examples 1 and 2 A sheet-like laminate made of ETFE and nylon 12 was prepared according to the above-mentioned method.
That is, first, as shown in FIG. 2, an ETFE film having a thickness of 300 μm was placed in the processing chamber 7. Then, a corona discharge treatment was performed for 10 seconds under the conditions of a frequency of 20 kHz and an output of 0.4 kW. Next, Example 1 used γ-aminopropylethoxysilane (a), and Example 2 used N-β
-(Aminoethyl) -γ-aminopropyltrimethoxysilane (b) was dissolved in methanol to prepare a coupling agent solution. Then, this is sprayed on the ETF
E was applied to the corona discharge treated surface and dried. On the other hand, a film-like nylon 12 having a thickness of 2 mm was prepared, and one surface thereof was heated and melted at 245 ° C. Then
E subjected to the corona discharge treatment and the coupling agent treatment
2 kgf / cm 2 of TFE and nylon 12 subjected to the heat-melting treatment in a state where the treated surfaces are in contact with each other.
In condition ^2, 3 minutes, after pressing a press, and cooled to room temperature, and an object, to prepare a sheet-like laminate.

[0026]

Comparative Example 1 No corona discharge treatment was performed. And
The coupling agent treatment was performed using γ-aminopropylethoxysilane (a). Other than this, Examples 1 and 2
The same operation as described above was performed to produce a sheet-like laminate.

[0027]

Comparative Example 2 Vinylethoxysilane (c) was used as a coupling agent. Except for this, the same operation as in Examples 1 and 2 was performed to produce a sheet-like laminate.

[0028]

Comparative Example 3 No corona discharge treatment and no coupling agent treatment were performed. Otherwise, the same operations as in Examples 1 and 2 were performed to produce a sheet-like laminate.

The thus obtained sheet-like laminates of Examples 1 and 2 and Comparative Examples 1 to 3 were subjected to a peeling test, a gasoline immersion test and a heat aging test according to the following methods. The results are shown in Table 1 below.

[Peeling Test] A 90 ° peeling test was performed. That is, as shown in FIG. 3, the peeled end of the partially peeled ETFE film 10a is perpendicularly (90 °) to the nylon 12 layer 15a using a strograph ( trade name, a tensile tester manufactured by Toyo Seiki Co., Ltd.). And pull at a peeling speed of 50 mm / min (in the direction of arrow A),
The peel strength was measured (JIS K 6256) .

[Gasoline Dipping Test] The sheet laminate subjected to the above-mentioned peeling test was immersed in gasoline at a temperature of 40 ° C. for 168 hours, and then subjected to a 90 ° peeling test again according to the above-mentioned measuring method (JIS K 7114) .

[Heat Aging Test] The sheet-like laminate subjected to the above-mentioned peeling test was heated at 125 ° C. for 168 hours, and again subjected to a 90 ° peeling test by the above-mentioned measuring method (JIS K 7212) .

[0033]

[Table 1]

From the above Table 1, it can be seen that the sheet laminates of Examples 1 and 2 have high adhesive strength, and the peel strength after gasoline immersion and heat aging treatment is almost the same as the initial peel strength. It turns out that there is no. In the measurement of the peel strength, the coupling agent layer was broken. On the other hand, in the laminate of Comparative Example Product 1 and Comparative Example Product 3, ETFE and nylon 12 were not bonded. The laminate of Comparative Example 2 had low adhesive strength and was peeled off by immersion in gasoline and heat aging.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a laminate of the present invention.

FIG. 2 is a configuration diagram showing an example of a corona discharge treatment device used in the present invention.

FIG. 3 is an explanatory view showing a method for measuring a peel strength.

[Explanation of symbols]

 Reference Signs List 10 Fluorine-based resin layer 15 Polyamide-based thermoplastic resin layer 16 Aminosilane-based coupling agent treated layer

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C08L 27/12 C08L 27/12 (72) Inventor Katsuhiko Yokoe 3600 Gezu, Kita-gaiyama, Komaki-shi, Aichi Tokai Rubber Industries, Ltd. (72) Inventor Hiroaki Ito Komaki-shi, Aichi Prefecture, Kita-gaiyama, Gezu 3600 Tokai Rubber Industries Co., Ltd. (56) References JP-A-61-164816 (JP, A) JP-A-5-245989 (JP) , A)

Claims (3)

(57) [Claims] 1. A laminate comprising a polyamide-based thermoplastic resin layer laminated on a surface of a fluorine-based resin layer, wherein the laminated surface of the fluorine-based resin layer is formed on a rough surface, and A laminate having an aminosilane-based coupling agent-treated layer formed thereon. 2. The laminate according to claim 1, wherein the laminate surface of the fluorine-based resin layer is formed to be rough by corona discharge treatment. 3. A method for producing a laminate comprising a polyamide-based thermoplastic resin layer laminated on a surface of a fluorine-based resin layer,
A step of performing a corona discharge treatment on the surface of the fluororesin layer, a step of forming a treatment layer on the surface of the discharge-treated fluororesin layer by an aminosilane coupling agent treatment, and a step of treating the aminosilane coupling agent treatment layer A step of facing the surface of the fluororesin layer on which the surface is formed and the surface of the above-mentioned polyamide-based thermoplastic resin layer and bonding them together by utilizing heat melting.