JP2505327B2 - Laminated material containing soft fluororesin - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a laminate containing a fluororesin and a polyamide resin, such as alcohol,
The present invention provides a material suitable for use in hoses, tubes, gaskets, etc., which require high chemical resistance to acids and the like.

[0002]

PRIOR ART AND PROBLEMS In recent years, fluororesin has
It is used in fields that make use of its features such as chemical resistance and non-adhesiveness, but fluororesin has the problem of high price, and various laminates are available for the purpose of lowering the price while maintaining the necessary functions. Is being considered.

On the other hand, polyamide resin is a material having well-balanced properties, and is particularly characterized by high strength, toughness, abrasion resistance, workability, etc.
It is used in many applications such as electrical parts and general mechanical parts. In addition, among polyamide resins, its tensile modulus is 50
The so-called flexible nylon resin of less than 00 Kgf / cm ² is widely used as tubes, hoses, etc. of automatic machines, robots, automobiles, etc. by utilizing its flexibility.

However, these polyamide resins have a drawback that they are inferior in methanol resistance and acid resistance, so that there is a problem in applying them to applications where resistance to them is particularly required. For example, nylon 11 or nylon 12 is used as a material for a fuel hose for automobiles, but this hose swells with a methanol-based fuel and is difficult to use. In addition, there is a drawback that the life is short in a portion where sour gasoline resistance is required. Therefore, many attempts have been made to improve the chemical resistance of the liquid contact portion by laminating these polyamide resin and fluororesin. However, since fluororesins generally lack compatibility with other resins, pretreatment such as corona discharge treatment or sodium etching treatment on the fluororesin surface is required for lamination, and both layers are laminated with an adhesive. The way to do is taken. However, this method has a drawback in that, for example, when manufacturing a laminated hose, the process is complicated and the operation is complicated.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention provides a laminated material which utilizes the excellent properties of polyamide resin and is also excellent in chemical resistance such as methanol resistance and acid resistance. It is intended to provide a laminate which does not require pretreatment of materials and can be easily laminated only by heat fusion.

[0006]

[Means for Solving the Problems] In view of the above problems, the present inventors have earnestly studied the lamination of a polyamide resin and a fluororesin, and as a result, as a chemical resistant layer, polyvinylidene fluoride resin (PVDF) was used. By using the resin containing the main component and using the resin containing the mixed resin of the soft fluororesin and the polyamide resin as the main component as the adhesive layer with the polyamide resin, a laminate that can be easily laminated by only the desired heat fusion can be obtained. They have found that they can be obtained and have reached the present invention.

That is, as the fluororesin for forming the chemical resistant layer, in consideration of heat fusion with the polyamide resin, the melting point (170 to 170-) of the polyamide resin, particularly flexible nylon is considered.
It is desirable to have a melting point as close to 180 ° C as possible, in that sense PVD with a melting point of 165 to 175 ° C.
F was optimal. However, PVDF and the polyamide resin cannot be bonded simply by thermocompression bonding, and it is necessary to interpose a compatible adhesive layer between them. Examples of the resin for the intermediate layer include one or more monomers containing at least one fluorine-containing monomer disclosed by the present inventors in Japanese Patent Publication No. 62-34324, a double bond and a peroxy group in the molecule. A fluorine-containing elastic copolymer (stem polymer) having a glass transition temperature of room temperature or lower is produced by copolymerizing a monomer having a bond at the same time, and a vinylidene fluoride monomer is added to 100 parts by weight of the stem polymer. A mixed resin of a soft fluororesin and a polyamide resin, which is obtained by graft-polymerizing 20 to 80 parts by weight of the body, was the most suitable.

This soft fluororesin is compatible with both PVDF and polyamide resin and forms a good hot melt adhesive layer between PVDF and polyamide resin.
As a monomer having a double bond and a peroxy bond at the same time in the molecule used here, t-butylperoxymethacrylate, unsaturated peroxyesters such as t-butylperoxycrotonate, and t-butylperoxyallylcarbonate, Unsaturated peroxycarbonates such as p-menthane peroxyallyl carbonate can be exemplified.

The composition of the fluorine-containing elastic copolymer is a binary copolymer of vinylidene fluoride (VDF) and hexafluoropropene (HFP), and a ternary copolymer of VDF, HFP and tetrafluoroethylene (TFE). Examples thereof include polymers and binary copolymers of VDF and chlorotrifluoroethylene (CTFE), but the composition thereof is not particularly limited.

The resin used for the chemical resistant layer is PVDF.
In addition to, PVDF segment-containing soft fluorine tree
It is possible to use a resin and a mixed resin of these two resins. this
The resin used for these chemical-resistant layers is the required
Selectable depending on chemical properties, thickness of each layer and degree of flexibility
Is done. Chemical resistance is high and hard like PVDF.
Resin is better, but when it is used for hoses, etc.
The bendability will be impaired. Furthermore, the softness used for the adhesive layer
As needed for mixed resin of fluororesin and polyamide resin
Polyamide resin can be added by adding PVDF
Considering the compatibility with
The amount of PVDF added may not exceed 100 parts by weight.
desirable. Flexibility that requires the resin mixture ratio of the adhesive layer
Determined in consideration of the degree of sex and the permeability of chemicals
However, the amount of polyamide resin mixed is PVDF and soft
10 to 120 with respect to 100 parts by weight of the mixed resin of the base resin
Parts by weight are desirable. Polyamide resin is less than this range
If it does not, the adhesion to the outer layer of polyamide resin is weak.
If it exceeds this range, the chemical resistance layer
Adhesiveness is impaired. As a method of mixing these resins,
Two-wire type, as used in general thermoplastics
The melt-kneading method using a extruder or extruder is suitable.
You. Various polyamide resins are commercially available.
Can be used, but consider the flexibility of the laminate used for hoses, etc.
The tensile modulus of elasticity is 5000 Kgf / cm ²The following Iwayu
Flexible nylon resin is desirable. Also for polyamide resin
A plasticizer added to improve flexibility can also be used.
You.

In the present invention, the thickness of each layer is not limited, and the thickness of each layer may be determined in consideration of the required characteristics so that the thickness will be suitable for the intended use, but generally from the viewpoint of price. It is advantageous to use the fluororesin layer as thin as possible.

Since the laminated material of the present invention can be produced only by heat welding, it is possible to form a hose having a three-layer structure by coextrusion molding, particularly for a fuel hose for automobiles for improving methanol resistance or sour gasoline resistance. Is extremely useful.

[0013]

The present invention will be described in detail below with reference to examples and reference examples, but the present invention is not limited thereto.

[Preparation Example] ( A) Production of Soft Fluorine Resin Pure water 50 was put in a stainless steel autoclave of 100 L capacity.
Kg, 100 g of potassium persulfate, 150 g of ammonium perfluorooctanoate and 100 g of t-butylperoxyalcarbonate are added, and after evacuation, 12.5 kg of vinylidene fluoride monomer and 7.55 kg of chlorotrifluoroethylene monomer are charged and stirred at 50 ° C. The polymerization reaction was carried out at the temperature of 20 hours. The product was obtained in the form of white latex, which was salted out to obtain rubber-like particles. After washing with water and vacuum drying, unreacted t-butyloxyallyl carbonate was removed by washing with n-hexane, and vacuum drying was performed again to obtain 16 kg of an elastic copolymer as a white powder. The DSC curve of this elastic copolymer has an exothermic peak at 160 to 180 ° C. based on the decomposition of peroxy groups, and the active oxygen content of the elastic copolymer is 0.0 by the iodometric titration method.
It was measured as 42%.

In the next step, 12 kg of the elastic copolymer of white powder and Freon R-113 (75 kg) were added to a stainless steel autoclave having a capacity of 100 L. After evacuation, 6 kg of vinylidene fluoride monomer was charged and the mixture was heated at 95 ° C. for 24 hours. Polymerization was carried out. The resulting polymer was separated from the solvent and then dried to obtain 16.6 kg of a soft fluororesin as a white powder.
Calculated from the yield, this soft fluororesin is obtained by graft-polymerizing 38.3 parts by weight of vinylidene fluoride monomer with respect to 100 parts by weight of the fluorinated elastic copolymer.

( B) Production of soft fluororesin pellets The soft fluororesin obtained in (A) above was pelletized at a temperature of 180 to 200 ° C. using an extruder having a diameter of 30 mm (L / D = 22). .

( C) Production of mixed resin sheet Chemical resistant layer (inner layer) Soft fluororesin pellets obtained in (B) and SOLEF1010 pellets manufactured by SOLVEY as PVDF were tumbler mixed at a mixing ratio shown in Table 2 to obtain a mixed resin. L /
Extrusion was carried out at a temperature of 180 to 220 ° C. from a 30 mm caliber extruder having D = 22 and a sheet die to produce a sheet having a width of 150 mm, a thickness of 0.5 mm and a thickness of 1.0 mm.

The soft fluororesin pellets obtained in the intermediate layer (B), PVDF and polyamide resin nylon 12 manufactured by ATOCHEM
(Brand name Rilsan AESN 0 P40TL pellets dried at 80 ° C. for 2 hours) were mixed in a tumbler at a mixing ratio shown in Table 2, and the mixed resin was mixed with L / D = 22 of 30.
180-235 from mm caliber extruder and sheet die
Extruded at a temperature of ℃, width 150mm, thickness 0.5mm and 1.
A 0 mm sheet was produced.

( D) Outer layer for production of polyamide resin sheet Nylon 12 pellets (dried at 80 ° C. for 2 hours) used above were 180-235 ° C. from L / D = 22 extruder with 30 mm diameter and sheet die. Sheets having an extruded width of 150 mm and a thickness of 1.0, 1.5 and 2.0 mm were produced at the temperature of.

(E) Measurement of Tensile Elastic Modulus of Each Sheet From the 1 mm thick sheets obtained in the above (B) to (D), JIS K
Punching out No. 3 dumbbell-shaped test piece specified in 6301,
It was pulled at a rate of 10 mm / min at 23 ° C. with an Instron type tensile tester. The tensile elastic modulus was calculated from the slope of the initial linear portion of the obtained stress-strain curve. The results are shown in Table 1, and it can be seen that the chemical resistance layer and the intermediate layer vary in flexibility represented by elastic modulus depending on the composition of the constituent resin.

[0021]

[Table 1]

[Examples and Reference Examples] ( A) Manufacture of Laminated Product The chemical resistant layer (inner layer) obtained in Preparation Example (C) was cut into 0.5 mm thick sheets of 100 × 100 mm to obtain 1 mm thick, Two
Place it in the center of a 00 mm square stainless steel plate, and 0.1 m to prevent welding at the 50 x 100 mm area on one side of the sheet.
After placing the m-thick PTFE film, the 0.5 mm-thick intermediate layer resin sheet obtained in Preparation Example (C) 100 × 100 mm
Then, the PTFE film and the outer layer polyamide resin sheet (1.0 mm thickness) obtained in Preparation Example (D) were similarly stacked, and a 1 mm thick, 200 mm square stainless steel flat plate was placed.

The sheet sandwiched between the stainless steel plates is 20
Put in a compression molding machine heated to 0 ℃, after the remaining heat without applying pressure for the first 10 minutes, transfer to a water-cooled compression molding machine, pressurize at a pressure of ²⁰ Kgf / cm ² for 5 minutes, and cool. A laminate (2 mm thick) was created.

( B) Evaluation of Adhesiveness of Laminated Body A test piece having a width of 25 mm and a length of 100 mm is cut out from the sheet of the laminated body produced in the above (A) so that the unwelded portion is in the longitudinal direction, and adhesion between layers The force was measured according to JIS K6854 [Test method for peeling adhesive strength of adhesive] to measure 180 degree peeling adhesive strength at room temperature. The results are shown in Table 2. The results are shown as the average value on the trough side and the peak value of the wavy portion of the tensile load curve in the peel test.

[0025]

[Table 2]

( C) Evaluation of Chemical Resistance of Laminated Product By the same method as in (A) above, a laminated product was manufactured in which the entire surface was welded without sandwiching a PTFE film for preventing welding.

Evaluation of Acid Resistance The result of measuring the weight change of the laminate after 30 days when immersed in 60% nitric acid at room temperature with the chemical resistant layer inside was measured by a Yamazaki lining tester based on ASTM C868-77. The results are shown in Table 2 together with a reference example in the case of using a 2 mm thick sheet of polyamide resin alone. Compared with the reference example, the laminate of the present invention clearly has improved acid resistance on the inner surface.

Evaluation of Methanol Resistance 100 cc of methanol was placed in a stainless steel cup having a bottom plate of 66 mmφ (34.2 cm 2) and a height of 50 mm (a lid is provided on the top so that the lid can be covered with a sheet), and the chemical resistance is set. The laminated sheet having a thickness of 2 mm and a diameter of 85 mm and having a metal mesh was put on the lid, and the periphery was sealed and tightened. The container was placed face down in an oven with methanol in contact with the laminate, and the weight change was measured to calculate the permeation amount (mg / hr) at 40 ° C. Again 14
The rate of change in weight of the laminate itself after the lapse of days was also measured.

The results are shown in Table 2 together with a reference example in the case of using a 2 mm thick sheet of polyamide resin alone, which is clear in the laminate of the present invention as compared with the reference example (-8.3% weight loss). In addition, the inner methanol resistance and the methanol barrier property are improved.

[Comparative Example 1] PVDF / nylon 12 = 100 /
The laminated body of No. 50 was manufactured by the same method as in Example 1 (A), and the adhesiveness with each layer was evaluated in the same manner as in Example 1 (B). The results are shown in Table 3. Compared with Example 1, there were many variations in the adhesive strength, and PVDF /
The non-uniformity of the blended state of Nylon 12 is apparent.

[0031]

[Table 3]

Comparative Example 2 A two-layer laminate comprising a 0.5 mm thick chemical resistant layer and a 1.5 mm thick polyamide layer was prepared as Example 1.
It was manufactured in the same manner as in (A), and the adhesiveness was evaluated in the same manner as in Example 1 (B). The results are shown in Table 4,
It has a very low adhesive strength as compared with Example 1,
The effect of providing the intermediate layer of the present invention is clear.

[0033]

[Table 4]

[0034]

Since the laminated material containing the soft fluororesin of the present invention can be produced only by heat welding, it can be easily formed into a tube or a hose by coextrusion molding, sour gasoline resistance and acid resistance are excellent and high strength. It is suitable as an automobile fuel hose having toughness.

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Claims (2)

(57) [Claims] 1. A laminated material comprising a layer made of a mixed resin of polyvinylidene fluoride resin and a soft fluororesin and a layer made of a polyamide resin which are heat-welded through a mixed resin layer of a soft fluororesin and polyamide , Low soft fluororesin
At least one monomer containing at least one fluorine-containing monomer
Body and a monomer that simultaneously has a double bond in the molecule
In combination, the glass transition temperature is below room temperature.
100 parts by weight of fluorine elastic copolymer (trunk polymer)
20 to 80 parts by weight of vinylidene fluoride monomer
A laminated material containing a soft fluororesin, which is a combined soft fluororesin . 2. A layer made of a mixed resin of polyvinylidene fluoride resin and a soft fluororesin and a layer made of a polyamide resin are heat-welded through a three-component mixed resin layer of a polyvinylidene fluoride resin, a soft fluororesin and a polyamide. Product
Layer material and at least one soft fluororesin
In the molecule with one or more monomers including the fluorine-containing monomer
By copolymerizing with a monomer having a double bond at the same time,
Fluorine-Containing Elastic Copolymers with Glass Transition Temperatures below Room Temperature
100 parts by weight of body (stem polymer) vinylidene fluoride
20-80 parts by weight of vinyl monomer
Laminate materials including soft fluorine resin, which is a fluororesin.