JPH0689159B2 - Polymer composite manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a method for producing a polymer composite useful as a load bearing structural material or the like.

<Prior Art> Fiber-reinforced plastics are regarded as important as load-bearing structural materials because of their dramatically improved physical properties, and various kinds of materials have been developed and put into practical use. The production of such a composite material requires a step of arranging separately produced reinforcing fibers in one direction and a step of further impregnating a matrix, and at that time, a complicated stepwise operation such as a step performed in an autoclave is included. Need.

On the other hand, the strength and durability of the composite material largely depend on the state of the interface between the reinforcing fiber and the matrix polymer. Since the fiber itself is a macro at the interface between the two, defects existing there propagate to the macro and lead to the destruction of the composite material.

In order to solve such a deficiency, instead of a fibrous reinforcing material that can be dispersed only in a macro shape, a high modulus reinforcing polymer and a matrix polymer are dissolved in a common solvent, and both are micro-dispersed. Mix by molecular order and solidify /
It has been studied to produce a polymer composite resistant product in which the reinforcing polymer is dispersed and mixed in an extremely microscopic state and the reinforcing polymer is oriented by molding.

The present inventors have used, as an organic polymer fiber, a polymer for reinforcing a polyazole-based polymer such as poly-p-phenylene benzobisthiazole, which gives an excellent tensile modulus, in a combination system with various matrix polymers. Although studies have been conducted on increasing the modulus, there were drawbacks such as a lower tensile modulus than the expected additivity value when both polymer components were sufficiently oriented. Also,
In order to obtain a molded article in which a film of a polymer composite is laminated, it is advantageous in terms of molding to increase the thickness of the film, but in conventional wet molding, when the thickness is increased, the coagulability deteriorates, No good film was obtained.

<Problems to be Solved by the Invention> An object of the present invention is to solve the above problems.
It is to achieve high modulus and thick film in a system using a polylene-based polymer such as phenylenebenzobisthiazole as a reinforcing polymer and a flexible polymer as a matrix polymer.

<Means for Solving the Problems> The inventors of the present invention have earnestly studied to obtain a polymer composite having high-performance mechanical and thermal properties, and as a result, one component of the coagulation bath composition was added to the polymer solution before solidification. It was found that when an appropriate amount of water is contained in advance to form a film, an excellent polymer composite can be obtained even in a thick film.

That is, according to the present invention, a polymer solution mainly containing a reinforcing polymer (A) substantially composed of a polyazole having a rod-like skeleton, a matrix polymer (B) having a fusion property and a solvent (C) is treated with water. In a method for producing a polymer composite, which comprises introducing into a coagulation bath containing water and forming a film, the polymer composite is characterized in that the solvent (C) contains water at least 1 (wt)% or more in advance. Regarding the manufacturing method of the body.

The reinforcing polymer (A) used in the present invention has the following formula [Wherein, X represents -S-, -O- or -NH-,
The bonds (a) and (b) are bonds that further form an azole ring or a hydrocarbon ring, or a hydrogen atom is bonded to one of them and the other is a bond. ] A substantially rod-like skeleton polyazole having an azole skeleton represented by
There are polymers described in the specification of No. 7,407, and polyazoles such as poly-p-phenylene benzobisthiazole, poly-p-phenylene benzoxazole, and poly-p-phenylene benzobisimidazole can be mentioned.

Regarding the molecular weight of the reinforcing polymer (A), the intrinsic viscosity which is a standard of the molecular weight is usually 1 or more, preferably 2 or more.

Matrix polymer (B) used in the present invention
Is soluble in the same solvent as the reinforcing polymer (A). Nylon 6, nylon 66, nylon 610, nylon 1
2.Nylon 11 and other aliphatic polyamides, polyhexamethylene isophthalamide and other aromatic polyamides, ether groups and other flexible group-introducing flexible aromatic polyamides, polyester, polycarbonate, polyvinyl acetate, polysulfone, poly Examples thereof include ether sulfone, polyether imide, polyether ketone, polyphenylene sulfide, and the like.

A common solvent for the reinforcing polymer (A) and the matrix polymer (B) is used as the solvent (C). The common solvent may be any solvent that can dissolve the constituent polymers, and examples thereof include concentrated sulfuric acid and an acidic solvent of methanesulfonic acid. These may be appropriately mixed and used.

Water (coagulation bath component) must be contained in an amount of 1 (wt)% or more in these solvents (C). Further, it is not preferable to contain too much water, and it is usually 8% or less.

The coagulation bath is preferably water alone or a mixed aqueous solution of the solvent (C) and water.

In the method of the present invention, a specific amount of water is previously contained in the polymer solution before solidification. As a result, even if the film is thick, it is possible to form a film with a uniform solidification and a high modulus film can be obtained.

Furthermore, in the method of the present invention, the effect can be further exhibited by combining with the phase transition transient film formation method.

That is, when a polymer solution having optical anisotropy is heated initially at room temperature, a polymer having an appropriate polymer concentration range is optically isotropic in a temperature range of 50 to 90 ° C. If the polymer solution is exposed to the temperature atmosphere from the solution in this state, the polymer solution is transformed from an isotropic phase to an anisotropic phase when immersed in a coagulation bath having a temperature at which optical anisotropy occurs. It is possible to obtain a molded product having excellent mechanical properties by solidifying in the transient state of.

In the method of the present invention, when water is contained in the polymer solution, the temperature of its phase transition is lowered, and the polymer concentration can be further increased by the lowered amount, which is preferable for obtaining a good molded product.

Another effect of including water in the polymer solution is to significantly reduce the solution viscosity of the polymer solution. By reducing the solution viscosity, the fluidity of the solution during film formation is stabilized, and the polymer concentration can be increased. Due to these two effects, a film formed from a polymer solution containing the components of the coagulation bath can obtain a molded product with excellent performance.

As a film forming method, the polymer solution extruded from a T-die or the like may be directly immersed in the coagulation bath, or after casting on a drum, the drum may be immersed in the coagulation bath. The unstretched film after solidification needs to be neutralized with ammonia, sodium hydroxide or the like, especially in an acid solvent system, after sufficiently removing the residual solution.

The dry film becomes a high-modulus film by a normal stretching operation that is then used for stretching the film or the like.

The ratio of the reinforcing polymer (A) and the matrix polymer (B) used in the present invention is preferably in the range of 5 to 45 (wt)% A / A + B. Reinforcing polymer (A) is 5
If it is less than (weight)%, the reinforcing effect is small.
When it exceeds (weight)%, the orientation of the reinforcing polymer (A) is lowered and it becomes difficult to exhibit the characteristics of the present invention.

<Effects of the Invention> According to the method of the present invention as described above, by preliminarily containing 1 (wt)% or more of water in the polymer solution, the phase transition temperature of the polymer solution is lowered and the solution viscosity is also reduced. Therefore, it is possible to manufacture a film molded product having excellent film thickness and mechanical properties.

<Examples> The effects of the present invention will be shown below with examples, and the percentages in the examples are based on weight unless otherwise specified. fiber·
The mechanical properties of the film are measured with a sample length of 4 cm at an elongation rate of 10% per minute.

Also, the intrinsic viscosity is ηinh obtained by a usual method at 30 ° C. after dissolving in 100% sulfuric acid or methanesulfonic acid or chlorosulfonic acid so that the concentration of the reinforcing polymer (A) is 0.2 g / 100 cc. is there. When the reinforcing polymer (A) dissolves in any of the above solvents, the lowest value among them is the intrinsic viscosity of the reinforcing polymer (A).

<Examples 1 to 3 and Comparative Example 1> As the reinforcing polymer (A), poly-p-phenylenebenzothiazole (abbreviated as PPBT) was polymerized according to a conventional method, and an intrinsic viscosity in a methanesulfonic acid solvent was 4.1. Obtained.

The matrix polymer (B) consists of 3,4'-diaminophenyl ether (50 mol%) and paraphenylenediamine (50
Mol%) and N-methylpyrrolidone in a concentration of 6% and dissolved in a dry nitrogen atmosphere, and after cooling to 5 ° C., terephthalic acid dichloride powder (100 mol%) was stirred vigorously. The solution was promptly added to the solution, a polymerization reaction was carried out at 35 ° C. for 1 hour, and the solution was precipitated with water and neutralized. Hereinafter, the polymer is abbreviated as PPOT-50. PPO
Ηinh of T-50 was 3.6 in sulfuric acid solvent.

PPBT and PPOT-50 were dissolved in methanesulfonic acid so that the component ratio was 30/70. The initial moisture content of methane sulfonic acid was 0.4%, and water was added to this to create methane sulfonic acid with a moisture content of 1.5, 2.5, 3.5, 4.5%, and the total polymer concentration was 6.6%. A polymer solution was prepared so that The temperature at which a water content of 0.4% changes from anisotropy to an isotropic phase (phase transition temperature) is 98 ° C, but water is 1.5%.
%, 2.5%, 3.5%, 4.5%, the phase transition temperatures decreased to 83 ℃, 78 ℃, 72 ℃ and 65 ℃. The solution viscosity was 110,000 poise when the water content was 0.4%, but the water content was 1.5-
At 4.5%, it was confirmed that the viscosity was remarkably reduced to 7500 to 5000 poise.

The polymer solution was pushed into a plunger, the T-die was heated to the temperature shown in Table 1 according to the content of each moisture content, and extruded into a coagulating bath through an air layer. As the coagulation bath, 45 ° C. of a 60% aqueous solution of methanesulfonic acid was used as the first stage bath, and 30 ° C. of a 30% aqueous solution of methanesulfonic acid was used as the second stage bath.

The coagulated film was thoroughly washed with water, neutralized with an aqueous sodium hydroxide solution, and then washed with water for another 24 hours. The film was placed in a fixed frame, air-dried, and then stretched at a temperature of 400 ° C. to obtain a stretched uniaxially oriented film at a stretching ratio of 0.8.

Table 1 shows the physical properties of each film. From these results, it is recognized that the tape performance is improved by preliminarily containing 1.0% or more of the coagulation bath component water in the solution.

Claims (2)

[Claims] 1. A polymer solution containing mainly a reinforcing polymer (A) substantially composed of a polyazole having a rod-like skeleton, a fusible matrix polymer (B) and a solvent (C), and coagulating the polymer solution with water. In a method for producing a polymer composite, which comprises introducing into a bath to form a film, the solvent (C) contains water in advance at least 1 (wt)% or more. Manufacturing method. 2. The method for producing a polymer composite according to claim 1, wherein water (1) is contained in the solvent (C) in advance in an amount of 1 to 8% by weight.