JP4619650B2 - Laminated hose - Google Patents

Description

  The present invention relates to a fluorine-containing copolymer excellent in chemical resistance, heat resistance, weather resistance, and stress crack resistance, and excellent in adhesion to a polyamide resin, and a laminated hose made of a polyamide resin.

  Fluorine-containing copolymers such as polytetrafluoroethylene, tetrafluoroethylene / perfluoro (alkyl vinyl ether) copolymers, and ethylene / tetrafluoroethylene copolymers have chemical resistance, heat resistance, weather resistance, gas barrier properties, etc. It has excellent characteristics and is used in various fields such as the semiconductor industry and the automobile industry.

  For example, the application of fluorine-containing polymers to components such as tanks, hoses and tubes, particularly to fuel hoses used in automobile engine rooms exposed to harsh conditions such as high-temperature environments has been studied. The fuel hose is a piping hose for transferring a gasoline-based fuel containing an alcohol or an aromatic compound such as methanol or ethanol.

  In particular, a fuel hose composed of a multilayer laminated hose containing a fluorine-containing copolymer (hereinafter simply referred to as “laminated hose”) has been studied as satisfying various required characteristics. In the laminated hose, the inner layer material that comes in direct contact with the fuel must use a resin that has a fuel barrier property that does not easily permeate the fuel and a chemical resistance to erosive liquids such as ethanol and methanol contained in the fuel. It is. In this respect, the fluorine-containing copolymer is suitable as an inner layer material because it is excellent in chemical resistance, heat resistance and gas barrier properties. In particular, an ethylene / tetrafluoroethylene copolymer (hereinafter referred to as ETFE) is preferable as an inner layer material of a fuel hose because it is excellent in fuel barrier properties.

  On the other hand, as the outer layer material of the fuel hose, polyamide resins such as polyamide 6, polyamide 11 and polyamide 12 having excellent mechanical properties and durability have excellent properties. Preferred to form.

  Conventionally, when trying to manufacture a laminated hose including a laminated structure of an inner layer made of a fluorine-containing copolymer and an outer layer made of a polyamide resin, there has been the following problem. That is, the fluorine-containing copolymer inherently has poor adhesiveness, and even when the hose or the like of the fluorine-containing copolymer is directly covered with a base material made of a polyamide resin as an outer layer, sufficient adhesive strength cannot be obtained. If the adhesive force is insufficient, the layers are peeled off during use, which may cause major problems such as hose blockage and increased fuel permeation.

  Thus, a technique for improving the adhesion between layers in a laminated hose has been studied. For example, after the fluorocopolymer is first formed into a tube by extrusion, the outer surface of the fluorocopolymer tube is treated by various methods such as chemical treatment, corona discharge treatment, plasma discharge treatment, etc. Are introduced into the surface and chemically activated. Next, after applying an adhesive as required, a polyamide resin is extruded and laminated on the outside of the tube of the fluorine-containing copolymer (for example, see Patent Document 1).

  According to such a method, a fuel hose excellent in adhesion between layers is manufactured. However, in this method, first, a three-step process of forming a hose of a fluorine-containing copolymer, activating this surface, and melt-extruding a polyamide tube on its outer surface must be carried out. However, there is a problem that the process is complicated and the productivity of the laminated hose is low.

  Therefore, the surface treatment of the fluorine-containing copolymer such as corona discharge treatment is not required, and it can be performed in a single step by a simple method such as coextrusion molding of the fluorine-containing polymer and a polyimide resin. There is a demand for a method that can be molded, in particular, to create a fluorine-containing copolymer having such properties.

As such a fluorinated polymer, it has been proposed to improve the adhesiveness of the fluororesin by copolymerizing maleic anhydride or dichloromaleic anhydride (see, for example, Patent Document 2). However, the copolymerizability of maleic anhydride and the like with fluorine monomer is not high enough, so in order to copolymerize maleic anhydride etc., supercritical hexafluoropropylene is used as a solvent or copolymerized or polymerized. It was necessary to carry out a polymerization operation using perfluorocarboxylic acid or NF ₃ as an initiator. In such a method, it is not always easy to arbitrarily produce a fluorinated copolymer designed for various uses.

  Patent Document 3 describes a fluorine-containing copolymer containing polymer units based on tetrafluoroethylene / polymer units based on isobutylene / polymer units based on vinyl benzoate / polymer units based on itaconic acid. However, the fluorine-containing copolymer is not intended for the formation of tubes and hoses, but is used for protective coatings on metals such as aluminum and copper. The temperature was as low as 100 ° C. and the heat resistance was insufficient.

  Furthermore, Patent Document 4 describes an ethylene / tetrafluoroethylene copolymer containing polymer units based on tetrafluoroethylene / polymer units based on ethylene / polymer units based on itaconic acid. However, such an ethylene / tetrafluoroethylene copolymer is not intended to form a tube or a hose, but is used for a protective coating of metal. The mechanical strength such as property was not sufficient.

US Pat. No. 5,554,425 (claims 1-9) JP-A-11-193132 (Claim 1, [0019] to [0020]) British Patent 1,087,999 (page 19, Example 3, Table III, claims 16-18) U.S. Pat. No. 3,445,434 (Claims 15-16)

  The present invention is a fluorinated copolymer which is strongly required to be realized on the background as described above, excellent in chemical resistance, heat resistance and weather resistance, and excellent in adhesion to polyamide resin. For the purpose of provision.

  As a result of intensive investigations from such a viewpoint, the inventors of the present invention achieved such a problem by using a fluorine-containing copolymer having a specific composition containing a polymer unit based on itaconic anhydride or the like, and the fluorine-containing copolymer and the polyamide resin. As a result, the present invention was completed.

According to the present invention, the following laminated hose is provided.
[1]
In a laminated hose comprising a laminate in which a fluorine-containing copolymer (A) layer and a polyamide resin (PA) layer are directly laminated, the fluorine-containing copolymer (A) comprises (a) tetrafluoroethylene. And / or polymerized units based on chlorotrifluoroethylene, (b) polymerized units based on fluorine monomers (excluding tetrafluoroethylene and chlorotrifluoroethylene), and (c) itaconic acid, itaconic anhydride, citraconic acid And polymerized units based on one or more selected from the group consisting of citraconic anhydride, and (a) is 50 to 99.8 mol% with respect to ((a) + (b) + (c)), ( b) is 0.1 to 49.99 mol%, (c) is 0.01 to 5 mol%, and the fluorine-containing copolymer has a volume flow rate of 0.1 to 1000 mm ³ / sec. Toss The multi-layer hose.

[2]
The fluorine-containing copolymer (A) further contains (d) a polymer unit based on a non-fluorine monomer, and the molar ratio of ((a) + (b) + (c)) / (d) is 100/5. The laminated hose as described in the item [1], which is 100 to 90/90.

[3]
The laminated hose according to the item [1] or [2], wherein the laminate is obtained by coextrusion molding.

Hereinafter, preferred embodiments of the present invention will be described in detail.
(Fluorine-containing copolymer)
In the laminated hose of the present invention (in the present invention, hose, tube and pipe are used as terms having the same meaning), the fluorine-containing copolymer layer (A) and the polyamide resin (PA) layer are directly formed. A laminated hose including laminated laminates, wherein the fluorine-containing copolymer (A) is basically composed of (a) tetrafluoroethylene (hereinafter referred to as “TFE”) and / or chlorotrifluoroethylene ( Hereinafter referred to as “CTFE”), (b) polymerized units based on fluorine monomers (excluding TFE and CTFE), and (c) itaconic acid (hereinafter referred to as “IAC”), itaconic anhydride. (Hereinafter referred to as “IAH”), citraconic acid (hereinafter referred to as “CAC”), and one or more selected from the group consisting of citraconic anhydride (hereinafter referred to as “CAH”). Is a fluorine-containing copolymer containing polymerized units based on.

  In the fluorine-containing copolymer of the present invention, the polymerized unit (a) is 50 to 99.8 mol%, the polymerized unit (b) with respect to the total polymerized unit ((a) + (b) + (c)). ) Is 0.1 to 49.99 mol%, and the polymerized unit (c) is 0.01 to 5 mol%. Here, ((a) + (b) + (c)) represents the sum of (a), (b), and (c).

  Preferably, (a) is 50 to 99 mol%, (b) is 0.5 to 49.9 mol%, and (c) is 0.00 with respect to ((a) + (b) + (c)). 1 to 3 mol%, more preferably (a) is 50 to 98 mol%, (b) is 1 to 49.9 mol%, and (c) is 0.1 to 2 mol%.

When the mol% of (a), (b) and (c) is within this range, the fluorine-containing copolymer is excellent in chemical resistance and heat resistance. Moreover, when the molar ratio of (b) is in this range, the fluorine-containing copolymer is excellent in moldability and mechanical properties such as stress crack resistance. Furthermore, when the molar ratio of (c) is within this range, the fluorine-containing copolymer is excellent in adhesiveness with a polyamide resin, and therefore it is preferable when a laminated hose is formed.

  In addition, IAC, IAH, CAC and CAH of the component (c) may be used alone or as a mixture. The above molar ratio represents the total amount when used as a mixture.

As the fluorine monomer in (b), vinyl fluoride, vinylidene fluoride, trifluoroethylene, hexafluoropropylene,
CF ₂ = CFOR ¹ (wherein R ¹ is a perfluoroalkyl group which may contain an oxygen atom having 1 to 10 carbon atoms. The same shall apply hereinafter.)

CF ₂ = CFOR ² SO ₂ X ¹ (wherein R ² is a perfluoroalkyl group which may contain an oxygen atom having 1 to 10 carbon atoms, X ¹ is a halogen atom or a hydroxyl group; the same shall apply hereinafter),
CF ₂ = CFOR ³ CO ₂ X ² (wherein R ³ is a perfluoroalkyl group which may contain an oxygen atom having 1 to 10 carbon atoms, X ² is a hydrogen atom or an alkyl group having 3 or less carbon atoms. The same applies hereinafter. ), CF ₂ = CF (CF ₂ ) _p OCF = CF ₂ (wherein p is 1 or 2),
CH ₂ = CX ³ (CF ₂ ) _q X ⁴ (wherein X ³ is a hydrogen atom or a fluorine atom, q is an integer of 2 to 10, and X ⁴ is a hydrogen atom or a fluorine atom. The same shall apply hereinafter.)
And perfluoro (2-methylene-4-methyl-1,3-dioxolane).

Preferred (b) fluorine monomers include, among the above, vinylidene fluoride, hexafluoropropylene,
CF ₂ = CFOR ¹ or CH ₂ = CX ³ (CF ₂ ) _q X ⁴
Even more preferably, CF ₂ = CFOR ¹ or ^{_{CH 2 = CX 3 (CF 2}} ) q X 4 may be mentioned.

Specifically, as CF ₂ = CFOR ¹ , CF ₂ = CFOCF ₂ CF ₃ , CF ₂ = CFOCF ₂ CF ₂ CF ₃ , CF ₂ = CFOCF ₂ CF ₂ CF ₂ CF ₃ , CF ₂ = CFO ( CF ₂ ) ₈ F and the like. Among them, CF ₂ = CFOCF ₂ CF ₂ CF ₃ is particularly preferable.

Further, as a specific example, as CH ₂ = CX ³ (CF ₂ ) _q X ⁴ , CH ₂ = CH (CF ₂ ) ₂ F, CH ₂ = CH (CF ₂ ) ₃ F, CH ₂ = _{CH (CF 2) 4 F,} CH 2 = CF (CF 2) 3 H, CH 2 = CF (CF 2) 4 H , and the like. Of these, CH ₂ ═CH (CF ₂ ) ₄ F or CH ₂ ═CH (CF ₂ ) ₂ F is particularly preferred.

(C) is at least one polymer unit selected from the group consisting of IAC, IAH, CAC and CAH. More preferably, (c) is a polymerized unit based on IAH or CAH (hereinafter, IAC, IAH, CAC and CAH are collectively referred to as “acid monomer”).

  As already mentioned, it is known to improve the adhesion of fluororesin by copolymerizing maleic anhydride or dichloromaleic anhydride, but in order to copolymerize maleic anhydride etc. It was necessary to perform a proper polymerization operation (Patent Document 2).

  On the other hand, as defined in the present invention, when an acid monomer such as IAC, IAH, CAC and CAH is used in the production of the fluorine-containing copolymer, the fluorine-containing polymer having a polymer unit based on the acid monomer is obtained by a normal polymerization operation. A copolymer is preferred because it can be easily obtained. In particular, when IAH or CAH is used in the production of the fluorinated copolymer, a fluorinated copolymer having polymerized units based on an acid anhydride can be easily obtained.

  In the fluorine-containing copolymer in the present invention, ((a) + (b) + (c)) is preferably 60 mol% or more, more preferably 65 mol% or more, and most preferably 68 mol% or more with respect to all the polymerized units. preferable.

  In addition to (a), (b) and (c), the fluorine-containing copolymer in the present invention preferably further contains (d) a polymer unit based on a non-fluorine monomer. Examples of the non-fluorine monomer in (d) include olefins having 3 or less carbon atoms such as ethylene and propylene; vinyl esters such as vinyl acetate; vinyl ethers such as ethyl vinyl ether and cyclohexyl vinyl ether. Preferred is ethylene, propylene or vinyl acetate.

  When the fluorine-containing copolymer in the present invention contains a polymer unit (d) based on such a non-fluorine monomer, the molar ratio of ((a) + (b) + (c)) / (d) is 100 / 5-100 / 90 is preferable, 100 / 5-5 / 100/80 is more preferable, and 100 / 10-100 / 65 is most preferable.

The most preferred specific examples of the fluorinated copolymer in the present invention containing the polymerized units (a), (b) and (c) and optionally containing the polymerized units (d) include the following. The That is, TFE / CF ₂ = CFOCF ₂ CF ₂ CF ₃ / IAH copolymer, TFE / CF ₂ = CFOCF ₂ CF ₂ CF ₃ / CAH copolymer, TFE / hexafluoropropylene / IAH copolymer, TFE / hexa Fluoropropylene / CAH copolymer, TFE / vinylidene fluoride / IAH copolymer, TFE / vinylidene fluoride / CAH copolymer, TFE / CH ₂ ═CH (CF ₂ ) ₄ F / IAH / ethylene copolymer, TFE / CH ₂ ═CH (CF ₂ ) ₄ F / CAH / ethylene copolymer, TFE / CH ₂ ═CH (CF ₂ ) ₂ F / IAH / ethylene copolymer, TFE / CH ₂ ═CH (CF ₂ ) ₂ F / CAH / ethylene _{copolymer, CTFE / CH 2 = CH (} CF 2) 4 F / IAH / ethylene _{copolymer, CTFE / CH 2 = CH (} CF 2) 4 F / CAH Ethylene _{copolymer, CTFE / CH 2 = CH (} CF 2) 2 F / IAH / ethylene _{copolymer, CTFE / CH 2 = CH (} CF 2) 2 F / CAH / ethylene copolymer.

  The fluorine-containing copolymer used in the present invention has a molding temperature that is close to the molding temperature of the polyamide resin so that the laminate can be molded by coextruding it with the polyamide resin that should form the outer layer. It is preferable. Therefore, the content ratio of the polymerization unit (a), the polymerization unit (b), the polymerization unit (c) and the polymerization unit (d) contained as necessary is appropriately adjusted within the above range, and the fluorine-containing copolymer It is preferable to optimize the melting point of the coalescence in relation to the molding temperature of the polyamide resin.

  In the present invention, the fluorine-containing copolymer has a functional group reactive with a polyamide resin, such as an ester group, a carbonate group, a hydroxyl group, a carboxyl group, a carbonyl fluoride group, and an acid anhydride, as a terminal group. This is also preferable because adhesion to the polyamide layer is improved. The terminal group is desirably introduced by appropriately selecting a radical polymerization initiator, a chain transfer agent, and the like used in the production of the fluorine-containing copolymer.

The volume flow rate of the fluorine-containing copolymer in the present invention (hereinafter referred to as "Q value".) Is preferably 0.1~1000mm ³ / sec, more preferably 5 to 500 mm ³ / sec, more preferably 10 to 200 mm ³ / Sec.

  The Q value is basically an index that represents the melt fluidity of the fluorine-containing copolymer, and is a value that serves as a measure of the molecular weight. That is, the larger the Q value, the lower the molecular weight, and the smaller the Q value, the higher the molecular weight. Therefore, if the Q value is too small, extrusion molding becomes difficult, whereas if it is too large, the mechanical strength of the fluorinated copolymer decreases.

  In the present invention, as shown in the examples described later, the Q value was measured in an orifice having a diameter of 2.1 mm and a length of 8 mm under a load of 7 kg at a temperature higher by 50 ° C. than the melting point of the resin using a flow tester manufactured by Shimadzu Corporation. This is the extrusion rate of the fluorine-containing copolymer during extrusion.

  The softening temperature of the fluorinated copolymer in the present invention is preferably 120 to 310 ° C, more preferably 150 to 300 ° C, and most preferably 180 to 300 ° C. Here, the softening temperature is the lowest temperature at which the melted trace of the fluorine-containing copolymer brought into contact with the heated brass mass adheres as described in Examples below.

  There is no restriction | limiting in particular about the manufacturing method of the fluorine-containing copolymer used in this invention, The polymerization method using the radical polymerization initiator generally used is employ | adopted. Examples of polymerization methods include bulk polymerization known per se; solution polymerization using organic solvents such as fluorinated hydrocarbons, chlorinated hydrocarbons, fluorinated chlorohydrocarbons, alcohols, hydrocarbons; aqueous media and, if necessary, Suspension polymerization using an appropriate organic solvent; emulsion polymerization using an aqueous medium and an emulsifier may be mentioned, and solution polymerization is most preferable. The polymerization can be carried out as a batch operation or a continuous operation using a one-tank or multi-tank stirring polymerization apparatus, a tube polymerization apparatus, or the like.

  Here, the radical polymerization initiator preferably has a decomposition temperature of 0 to 100 ° C. for obtaining a half-life of 10 hours, more preferably 20 to 90 ° C.

  Specific examples of preferable radical polymerization initiators include azo compounds such as azobisisobutyronitrile; non-fluorinated diacyl peroxides such as isobutyryl peroxide, octanoyl peroxide, benzoyl peroxide, lauroyl peroxide; diisopropyl peroxydicarbonate, etc. Peroxydicarbonates; peroxyesters such as tert-butylperoxypivalate, tert-butylperoxyisobutyrate, tert-butylperoxyacetate;

Fluorine-containing diacyl peroxide such as a compound represented by the formula (1);
(Z (CF ₂ ) _p COO) ₂ (1)
(Here, Z is a hydrogen atom, a fluorine atom or a chlorine atom, and p is an integer of 1 to 10.)
Examples include inorganic peroxides such as potassium persulfate, sodium persulfate, and ammonium persulfate.

  In the present invention, it is also desirable to use a chain transfer agent in order to control the Q value of the fluorine-containing copolymer within the above-mentioned preferable range.

  Examples of chain transfer agents include alcohols such as methanol and ethanol; 1,3-dichloro-1,1,2,2,3-pentafluoropropane (trade name, hereinafter referred to as “AK225cb” manufactured by Asahi Glass Co., Ltd.), 1 , Chlorofluorohydrocarbons such as 1-dichloro-1-fluoroethane; hydrocarbons such as pentane, hexane, and cyclohexane.

  In this case, when a chain transfer agent having a functional group such as an ester group, a carbonate group, a hydroxyl group, a carboxyl group, or a carbonyl fluoride group is used, as described above, the terminal group having reactivity with the polyamide resin is formed. Since it is introduced, it is preferable. Examples of such chain transfer agents include acetic acid, acetic anhydride, methyl acetate, ethylene glycol, propylene glycol and the like.

  The polymerization conditions of the fluorine-containing copolymer used in the present invention are not particularly limited, and the polymerization temperature is preferably 0 to 100 ° C, more preferably 20 to 90 ° C. The polymerization pressure is preferably from 0.1 to 10 MPa, more preferably from 0.5 to 3 MPa. Furthermore, the polymerization time is preferably 1 to 30 hours.

  The concentration of the acid monomer during the polymerization is preferably 0.01 to 5%, more preferably 0.1 to 3%, and most preferably 0.1 to 1% with respect to all monomers. When the concentration of the acid monomer is too high, the polymerization rate tends to decrease. When the concentration of the acid monomer is within the above range, the polymerization rate during production does not substantially decrease, and the adhesiveness of the fluorinated copolymer to the polyamide resin is good. During the polymerization, as the acid monomer is consumed in the polymerization, the consumed amount is preferably continuously or intermittently supplied into the polymerization tank, and the concentration of the acid monomer is preferably maintained within this range.

(Polyamide resin)
In the present invention, as the polyamide resin (PA) used for laminating with the fluorine-containing copolymer (A) to form a laminated hose, those known per se can be suitably used. That is, since the fluorine-containing copolymer in the present invention itself has high adhesion to the polyamide resin, the polyamide resin is not particularly limited. Examples thereof include polyamides such as polyamide 6, polyamide 66, polyamide 46, polyamide 11, polyamide 12, and polyamide MXD6 (semi-aromatic polyamide).

  Other known polyamide resins that can be used include polyamide 26, polyamide 69, polyamide 610, polyamide 611, polyamide 612, polyamide 6T, polyamide 6I, polyamide 912, polyamide 1012, polyamide 1212, polyamide PACM12, and the like. The above polyamides may be used alone or in a blend. Moreover, it can also be set as the copolymerization polyamide resin using the raw material monomer which forms these.

(Laminated hose)
The laminated hose of the present invention has a laminated structure in which an inner layer (I) made of a fluorinated copolymer and an outer layer (II) made of a polyamide resin are laminated, that is, [(II) / (I)] is a laminate including a basic laminate configuration.

  As long as the laminated hose of the present invention includes the above basic laminated structure, that is, as long as the laminated hose includes a structure in which the inner layer (I) made of the fluorinated copolymer and the outer layer (II) made of the polyamide resin are laminated in direct contact with each other. Further, it may be a multi-layer hose containing other fluorine resin or polyamide resin. The total number of layers in the case of a multi-layer hose is not particularly limited and can be at least 2 layers, but is usually 2 to 6 layers, more preferably 2 to 5 layers. The inner layer, especially the fluorine-containing copolymer or other fluorine-based resin forming the innermost layer, is provided with a conductivity-imparting filler such as carbon black according to a well-known and commonly used technique in the laminated hose field. You may make it express by adding to.

  The outer diameter of the laminated hose of the present invention is appropriately designed in consideration of the flow rate of the fuel to be handled, and the thickness thereof is a thickness that allows the fuel to be sufficiently permeable and can maintain the normal hose breaking pressure. In addition, the thickness is designed so as to maintain flexibility with a satisfactory degree of ease of assembling the hose and vibration resistance during use. Although these are not specifically limited, Usually, the outer diameter is preferably 4 to 30 mm, the inner diameter is 3 to 25 mm, and the wall thickness is preferably about 0.05 to 5 mm.

  Further, in the laminated hose of the present invention, the thickness of each layer is not particularly limited, and can be changed as needed depending on the physical properties of the resin, the total number of layers, usage, etc. The thickness of the layer is determined in consideration of characteristics such as fuel barrier properties, low temperature impact resistance, and flexibility of the laminated hose.

Specifically, the thickness of the inner layer (I) and the outer layer (II) is preferably 3 to 90%, respectively, with respect to the thickness of the entire laminated hose, and the thickness of the inner layer (I) is In consideration of the fuel barrier property, it is more preferably 5 to 80%, and further preferably 10 to 50% with respect to the thickness of the entire laminated hose.
As an example, a laminated hose having an outer diameter of 8 mm, an inner diameter of 6 mm, and a thickness of 1 mm (an inner layer of 0.25 mm and an outer layer of 0.75 mm) can be mentioned.

(Co-extrusion molding)
As a method for forming the laminated hose of the present invention, the polyamide resin forming the outer layer and the fluorine-containing copolymer of the inner layer are coextruded in a molten state, and both are heat-sealed (melt-bonded) to form a two-layer structure. Most preferably, it is by coextrusion forming a hose. Further, when it includes a laminated structure of three or more layers, it can be co-extruded according to this.

  Usually, the coextrusion molding method is a method of obtaining a laminate of two or more layers in the shape of a film, a tube or the like. That is, the melt of the resin that is to be kneaded and melted in two or more extruders equipped with screws to form the respective layers coming out from the discharge port is placed in a die placed at the tip of the extruder while in contact in the molten state. It is extruded and formed into a laminate.

  Regarding the extrusion temperature, the screw temperature is preferably 100 to 400 ° C, and the die temperature is preferably 150 to 400 ° C. The screw rotation speed is not particularly limited, but is preferably 10 to 200 rpm, and the residence time of the melt in the extruder is preferably 1 to 20 minutes.

  Further, as shown in the examples described later, it is preferable to pelletize each resin of the outer layer and the inner layer in advance. That is, using a high-speed rotary mixer such as a low-speed rotary mixer such as a V-type blender or tumbler, or a high-speed rotary mixer such as a Henschel mixer, with a predetermined amount of a resin to be mixed with a fluorine-containing copolymer or polyamide resin and a plasticizer. Are mixed and then melt-kneaded with a single-screw extruder, twin-screw extruder, twin-screw kneader, or the like to form pellets. A plasticizer or the like that is liquid at room temperature can be poured from the middle of a cylinder of a melt kneader to be melt kneaded.

  Pelletization is preferably performed by mechanically kneading and pelletizing at a temperature at which all resin components melt. In particular, in order to perform uniform mixing, it is preferable to use the same-direction twin screw extruder.

  In addition, when performing coextrusion molding, by supplying all the components that form the composition of each layer to the hopper of the extruder, compounding each layer in the extruder, and subsequently performing coextrusion molding, Compounding and coextrusion can be performed almost simultaneously.

(Example)
Hereinafter, the present invention will be specifically described with reference to examples, but the technical scope of the present invention is not limited thereto.
The MIT bending test, IAH or CAH content and softening temperature were measured by the following methods.

[MIT bending test]
Measured according to ASTM D2176. That is, a fluorine-containing copolymer (A) test piece having a width of 12.5 mm, a length of 130 mm, and a thickness of 0.23 mm was mounted on a MIT measuring instrument manufactured by Toyo Seiki Seisakusho, with a load of 1.25 kg and bending left and right. Each test piece was bent under an angle of 135 degrees and a bending frequency of 175 times / minute, and the number of times until the test piece was cut was measured. This test is a bending fatigue resistance test of the fluorine-containing copolymer and serves as an index of crack resistance. It shows that it is excellent in crack resistance, so that there are many times until it cut | disconnects.

[Content of IAH or CAH]
The fluorine-containing copolymer (A) was press-molded to obtain a 200 μm film. In the infrared absorption spectrum, the absorption peak of C═O stretching vibration in the polymer unit based on IAH or CAH in the fluorine-containing copolymer (A) appears at 1870 cm ⁻¹ . The absorbance of the absorption peak was measured, and the content M (mol%) of the polymerized units based on IAH or CAH was determined using the relational expression of M = aL. Here, L is the absorbance at 1870 cm ⁻¹ , and a is a coefficient. As a, a = 0.87 determined using IAH as a model compound was used.

[Softening temperature]
It was measured according to the description on page 7, lines 49 to 54 of British Patent 1,087,999. That is, the softening temperature is determined when the fluorine-containing copolymer (A) is brought into contact with a heated brass (copper / zinc alloy) block (block) and moved along this surface. trail) refers to the lowest temperature on the block. The softening temperature is also called sticking temperature.

[Synthesis Example 1]
(Preparation of fluorinated copolymer granules)
(1) A polymerization tank equipped with a stirrer having an internal volume of 94 liters was degassed, and 71.3 kg of 1-hydrotridecafluorohexane and 1,3-dichloro-1,1,2,2,3-penta were used as solvents. 20.4 kg of fluoropropane (Asahi Glass Co., Ltd., AK225cb), 562 g of CH ₂ ═CH (CF ₂ ) ₂ F, and 4.45 g of IAH were charged, and the temperature in the polymerization tank was raised to 66 ° C. The pressure was increased to 1.5 MPa / G with a gas having a molar ratio of 89/11.

(2) 1 L of a 0.7% 1-hydrotridecafluorohexane solution of tert-butylperoxypivalate as a polymerization initiator was charged to initiate polymerization. A monomer mixed gas of 59.5 / 40.5 molar ratio of TFE / E was continuously charged so that the pressure was constant during the polymerization. Also, CH ₂ ═CH (CF ₂ ) ₂ F in an amount corresponding to 3.3 mol% and IAH in an amount corresponding to 0.8 mol% are continuously added to the total number of moles of TFE and E charged during the polymerization. I was charged. 9.9 hours after the start of polymerization, when 7.28 kg of the monomer mixed gas was charged, the temperature inside the polymerization tank was lowered to room temperature and purged to normal pressure.

(3) The obtained slurry-like fluorine-containing copolymer 1 is put into a 200 L granulation tank charged with 77 kg of water, and the temperature is raised to 105 ° C. with stirring to granulate while removing the solvent by distillation. did. The obtained granulated product was dried at 150 ° C. for 15 hours to obtain 6.9 kg of the granulated product 1 of the fluorinated copolymer 1.

(4) From the results of melt NMR analysis, fluorine content analysis and infrared absorption spectrum analysis, the composition of the fluorinated copolymer 1 is a polymerized unit based on TFE / polymerization based on CH ₂ ═CH (CF ₂ ) ₂ F. The molar ratio of unit / polymerized unit based on IAH / polymerized unit based on E was 93.5 / 5.7 / 0.8 / 62.9. The melting point was 230 ° C., the softening temperature was 220 ° C., the Q value was 48 mm ³ / sec, and the MIT folding number was 38900 times.

(Preparation of two-layer laminated hose)
The granulated product 1 was melted at 260 ° C. with a residence time of 2 minutes by using an extruder to prepare pellets 1 of the fluorinated copolymer 1.

  Polyamide 12 (manufactured by Ube Industries, 3030JLX) was supplied to the cylinder forming the outer layer, and pellets 1 of the fluorinated copolymer were supplied to the cylinder forming the inner layer, and each was transferred to the transport zone of the cylinder. The heating temperatures in the transport zone for polyamide 12 and pellet 1 were 240 ° C. and 260 ° C., respectively. Two-layer coextrusion was performed at a temperature of the common die of 260 ° C. to obtain a two-layer laminated hose.

  The outer diameter of the laminated hose was 8 mm, the inner diameter was 6 mm, and the thickness was 1 mm. The outer layer of polyamide 12 and the inner layer of fluorine-containing copolymer 1 were 0.7 mm and 0.3 mm, respectively. The inner layer and the outer layer were extremely firmly adhered and could not be peeled off.

[Synthesis Example 2]
(Preparation of fluorinated copolymer granules)
(1) The polymerization tank used in Synthesis Example 1 was degassed and charged with 902 kg of AK225cb, 0.216 kg of methanol, 31.6 kg of CF ₂ = CFOCF ₂ CF ₂ CF ₃ , and 0.43 kg of IAH. The inside was heated to 50 ° C., and TFE was charged until the pressure became 0.38 MPa.

(2) As a polymerization initiator solution, 50 mL of a 0.25% AK225cb solution of di (perfluorobutyryl) peroxide was charged to initiate polymerization. TFE was continuously charged so that the pressure was constant during the polymerization. The above polymerization initiator solution was added as appropriate to keep the TFE feed rate substantially constant. A total of 120 mL of the polymerization initiator solution was charged. Further, IAH in an amount corresponding to 1 mol% of continuously fed TFE was continuously charged. At the time when 7.0 kg of TFE was charged 6 hours after the start of polymerization, the inside of the polymerization tank was cooled to room temperature, and unreacted TFE was purged.

(3) The obtained slurry-like fluorine-containing copolymer 2 is put into a 200 L granulation tank charged with 75 kg of water, and heated to 105 ° C. with stirring to granulate while removing the solvent by distillation. did. The obtained granulated product was dried at 150 ° C. for 5 hours to obtain 7.5 kg of the granulated product 2 of the fluorinated copolymer 2.

(4) From the results of melt NMR analysis, fluorine content analysis and infrared absorption spectrum analysis, the composition of the fluorinated copolymer 2 is a polymerized unit based on TFE / CF ₂ = CFOCF ₂ CF ₂ CF ₃ The polymerization unit based on / IAH was 97.7 / 2.0 / 0.3.
The melting point was 292 ° C., the softening temperature was 280 ° C., the Q value was 15 mm ³ / sec, and the MIT folding number was 46000 times.

(Preparation of two-layer laminated hose)
The granulated product 2 was melted at 260 ° C. with a residence time of 2 minutes by using an extruder to prepare pellets 2 of the fluorinated copolymer 2.

  Polyamide 12 (manufactured by Ube Industries, 3030JLX) was supplied to the cylinder forming the outer layer, and pellets 1 of the fluorinated copolymer were supplied to the cylinder forming the inner layer, and each was transferred to the transport zone of the cylinder. The heating temperatures in the transport zone for polyamide 12 and pellet 1 were 240 ° C. and 260 ° C., respectively. Two-layer coextrusion was performed at a temperature of the common die of 260 ° C. to obtain a two-layer laminated tube.

  The outer diameter of the laminated tube was 8 mm, the inner diameter was 6 mm, and the thickness was 1 mm. The outer layer of polyamide 12 and the inner layer of fluorine-containing copolymer 1 were 0.7 mm and 0.3 mm, respectively. The inner layer and the outer layer were extremely firmly adhered and could not be peeled off.

[Synthesis Example 3]
(1) The polymerization tank used in Synthesis Example 1 was degassed and charged with 53.1 kg of 1-hydrotridecafluorohexane and 42.5 kg of AK225cb. The temperature inside the polymerization tank was raised to 66 ° C., and TFE / E A monomer mixed gas having a molar ratio of 89/11 was charged and the pressure was increased to 1.5 MPa / G.

(2) 0.2 L of a 0.7% 1-hydrotridecafluorohexane solution of tert-butylperoxypivalate as a polymerization initiator solution was charged to initiate polymerization.
A monomer mixed gas of 59.5 / 40.5 molar ratio of TFE / E was continuously charged so that the pressure was constant during the polymerization. Further, IAH in an amount corresponding to 0.8 mol% with respect to the total number of moles of TFE and E charged during the polymerization was continuously charged. At 6.5 hours after the start of polymerization, when 7.28 kg of the monomer mixed gas was charged, the temperature in the polymerization tank was lowered to room temperature and purged to normal pressure.

(3) The obtained slurry-like fluorine-containing copolymer 3 is put into a 200 L granulation tank charged with 77 kg of water, and the temperature is raised to 105 ° C. with stirring to granulate while removing the solvent by distillation. did. The obtained granulated product was dried at 150 ° C. for 15 hours to obtain 7.5 kg of the granulated product 3 of the fluorinated copolymer 3.

(4) From the results of melt NMR analysis, fluorine content analysis and infrared absorption spectrum analysis, the composition of the fluorine-containing copolymer 3 is a molar ratio of polymerized units based on TFE / polymerized units based on IAH / polymerized units based on E. It was 99.2 / 0.8 / 67.0.

The melting point was 260 ° C., the softening temperature was 250 ° C., the Q value was 48 mm ³ / sec, the number of MIT folding was 4900 times, and the stress crack resistance was not sufficient. Therefore, the granulated product 3 of the fluorine-containing copolymer 3 is not preferable for laminating with a polyamide resin to form a laminated tube, and the tube was not manufactured.

  The laminated hose of the present invention can be formed by coextrusion molding due to the property of the fluorine-containing copolymer obtained by high adhesion to the polyamide resin, and the interlayer between the fluorine-containing body layer and the polyamide resin layer. A hose with high peel strength.

  The laminated hose comprising the fluorine-containing copolymer and the polyamide resin of the present invention is excellent in chemical resistance, heat resistance, corrosion resistance, oil resistance, weather resistance, etc., so that it is an automotive fuel tube or hose, fuel filler neck, cooling Liquid hose, brake hose, air conditioner hose, fuel transfer tube or hose, oil drilling pipe, paint spray tube, industrial hose, food hose tube, etc.

Claims (3)

In a laminated hose comprising a laminate in which a fluorine-containing copolymer (A) layer and a polyamide resin (PA) layer are directly laminated, the fluorine-containing copolymer (A) comprises (a) tetrafluoroethylene. And / or polymerized units based on chlorotrifluoroethylene, (b) hexafluoropropylene, CF ₂ = CFOR ¹ (wherein R ¹ is a perfluoroalkyl group which may contain an oxygen atom having 1 to 10 carbon atoms. The same.), CH ₂ = CX ³ (CF ₂ ) _q X ⁴ (where X ³ is a hydrogen atom or a fluorine atom, q is an integer of 2 to 10, and X ⁴ is a hydrogen atom or a fluorine atom. .) and perfluoro (2-methylene-4-methyl-1,3-dioxolane) to the fluoromonomer is at least one or more selected from the group consisting based polymerized units, and (c) Lee Containing polymerized units based on one or more selected from the group consisting of conic acid, itaconic anhydride, citraconic acid and citraconic anhydride, wherein (a) is relative to ((a) + (b) + (c)) 50 to 99.8 mol%, (b) is 0.1 to 49.99 mol%, (c) is 0.01 to 5 mol%, and the fluorine-containing copolymer (A) is tetrafluoroethylene. and / or chlorotrifluoroethylene, the fluorine monomer, and, itaconic acid, which itaconic anhydride, one or more selected from the group consisting of citraconic anhydride and citraconic acid as radical copolymerization, volume flow rate There was 0.1~1000mm ³ / sec, Ri fluorocopolymer der excellent adhesion with the polyamide resin (PA), and those fluorinated copolymer (a), at MIT bending test Number of bending , A laminated hose that having a crack resistance of at least 38,900 times, a layer of the fluorocopolymer of the multilayer hose (A), a layer of polyamide resin (PA), the strong delamination that can not be peeled A laminated hose characterized by having strength .   The fluorine-containing copolymer (A) further contains (d) a polymer unit based on a non-fluorine monomer, and the molar ratio of ((a) + (b) + (c)) / (d) is 100/5. The laminated hose according to claim 1, which is of ~ 100/90.   The laminated hose according to claim 1 or 2, wherein the laminated body is obtained by coextrusion molding.