JP2008163189A - Structure and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure prepared by impregnating a polyamide resin into a sheet-like material for reinforcing, which is light in weight and stable in mechanical characteristics, and a method for manufacturing the same. <P>SOLUTION: An alcohol-soluble polyamide resin composed of 20-50 wt.% of a caproamide unit, 10-45 wt.% of a hexamethylene adipamide unit, 15-40 wt.% of a hexamethylene sebacamide unit, and 0-55 wt.% of a dodecanamide unit is used. The structure is obtained by the method comprising the steps of dissolving the polyamide resin into a solvent such as an alcohol and water, impregnating the solution into the sheet-like material for reinforcing, and thereafter evaporating the solvent. The content of the polyamide resin is 5-15 wt.% of the structure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a structure in which a fiber woven fabric, a knitted fabric or a nonwoven fabric is impregnated with a polyamide resin composition, and a method for producing the same.

  Thermosetting resins such as epoxy resins, phenol resins, and unsaturated polyester resins are used for reinforcing fiber fabrics, knitted fabrics, and nonwoven fabrics with high strength and low elongation, such as glass fibers, carbon fibers, and aromatic polyamide fibers. It is publicly known to impregnate a semi-cured prepreg, laminate a plurality of the prepregs, and then heat laminate to form a laminated plate, or mold and cure into various shapes.

  However, this type of prepreg using a thermosetting resin requires strict management such as temperature conditions for storage until it is used for molding processing, and requires time and special equipment for curing. There was a problem with the above or work.

  Further, when a composite sheet of a fiber reinforcing material and a resin impregnated therein is used for adhesion, in the prepreg using the thermosetting resin, once cured, adhesion between the cured products is There were problems that a new adhesive was required, that the cured product could not be inflected by applying heat, and that it could not be reused by pulverization.

  On the other hand, a composite material combining a reinforcing sheet-like material and a thermoplastic resin is a combination of a reinforcing sheet-like material mainly made of glass fiber and various resins, which is mainly adhesive. The reinforcing sheet-like material specially treated for improvement was impregnated with a molten resin and solidified.

  Further, in the conventional structure using the above-described thermoplastic resin, in order to develop the reinforcing effect, the resin sheet should be satisfactorily impregnated into the reinforcing sheet-like material, which requires a large apparatus. There were also problems such as difficulty in making thin structures.

  In order to solve these points, Patent Document 1 and Patent Document 2 mention the use of methoxymethylated nylon. In Patent Document 1, as a specific example, methoxymethylated nylon “manufactured by Nagase Chemitex Corporation” A structure using “FS-350E2” is described. However, the nylon has limitations in processing of the structure, such as not completely dissolving in methanol unless it is substituted by 18% or more with a methoxymethyl group and requiring an organic acid such as citric acid for crosslinking.

In Patent Document 3, AQ nylon “C-40” manufactured by Toray Industries, Inc. is used as the alcohol-soluble polyamide resin, and glass cloth is used as the reinforcing fiber. The polyamide resin is 20% by weight or more. A structure is defined. In this, the polyamide resin content is specified to be 20% by weight or more in order to give a desired thermal adhesive force to the structure, but generally the strength and rigidity of the polyamide resin decreases as the water absorption increases. When the structure contains a polyamide resin in an amount of 20% by weight or more, there is a problem in the stability of mechanical properties such as a significant decrease in strength and rigidity.
JP 2001-181982 A JP-A-2-84577 Japanese Unexamined Patent Publication No. 63-218738

  An object of the present invention has been made in view of the above-mentioned problems, and is to provide a novel structure that can overcome each problem.

In view of the above situation, as a result of intensive studies to solve the above-mentioned problems, the present inventors have achieved light weight and excellent mechanical properties by adjusting the specific polyamide resin composition and its content in the structure. The invention of the structure having and the manufacturing method thereof has been reached.
That is, the present invention
(1) A structure obtained by impregnating a reinforcing sheet (B) with an alcohol-soluble polyamide resin (A), and the polyamide resin (A) content of the structure is based on the weight of the structure 5-15% by weight of a structure,
(2) The structure according to (1), wherein the reinforcing sheet-like material (B) includes one or more selected from glass fiber, carbon fiber, aramid fiber, and polyamide fiber, and (3) ) A method for producing a structure, wherein the polyamide resin (A) described in (1) is dissolved in alcohol, then impregnated into the reinforcing sheet (B), and the solvent is volatilized.

  In the present invention, a polyamide resin having a specific copolymerization ratio is dissolved in alcohol and impregnated into a reinforcing sheet-like material such as a fiber woven fabric, a knitted fabric or a non-woven fabric and volatilized. By setting it to 15% by weight, there is an effect of being lightweight and having excellent mechanical properties.

  The present invention will be described below.

  Polyamide resin (A) is caproamide unit (A1) 20-50% by weight, hexamethylene adipamide unit (A2) 10-45% by weight, hexamethylene sebamide unit (A3) 15-40% by weight and dodecanamide unit (A4) A copolymer consisting of 0 to 55% by weight is preferred in view of solubility in alcohol and mechanical properties.

  Furthermore, caproamide unit (A1) 30 to 45% by weight, hexamethylene adipamide unit (A2) 25 to 40% by weight, hexamethylene sebacamide unit (A3) 25 to 30% by weight, and dodecanamide unit (A4) A copolymer composed of 0 to 5% by weight is more preferable.

  These polyamide copolymers can be obtained by a known method. For example, methods such as solution polymerization, interfacial polymerization, solution polymerization, bulk polymerization, and solid layer polymerization are used as the polymerization method, and melt polymerization is generally most suitable. Furthermore, the low polymer of the above-mentioned polyamide can be put into an extruder or an injection molding machine, and the degree of polymerization can be increased completely or partially to obtain a polyamide having a suitable degree of polymerization.

  The term “alcohol-soluble” as used in the present invention is defined as alcohol-soluble when the resin component is completely dissolved at 5% by weight with respect to 95% by weight of methanol at 60 ° C.

  The reinforcing sheet-like material (B) impregnated with the polyamide resin (A) is formed in a woven fabric, a knitted fabric, a non-woven fabric or the like, and is not particularly limited. The types of reinforcing fibers are glass fibers, PAN and pitch carbon fibers, stainless fibers, metal fibers such as aluminum fibers and brass fibers, polyamide fibers, organic fibers such as aramid fibers, gypsum fibers, ceramic fibers, asbestos fibers, Examples thereof include zirconia fiber, alumina fiber, silica fiber, titanium oxide fiber, silicon carbide fiber, rock wool, potassium titanate whisker, silicon nitride whisker, and basalt fiber. Of these, glass fiber, PAN-based and pitch-based carbon fiber, aramid fiber, and polyamide fiber are preferable in terms of reinforcing effect.

The form of the reinforcing sheet (B) depends on the specific gravity of the fiber used, but in the case of carbon fiber, an apparent thickness of 0.05 to 0.4 mm and a basis weight of 70 to 300 g / m ² are preferable. When impregnating the dissolved polyamide resin (A), an apparent thickness of 0.1 to 0.3 mm and a basis weight of 100 to 200 g / m ² are more preferable.

  As a production method, the polyamide resin is dissolved in alcohol, and in this case, heating may be performed. Moreover, a C1-C6 alcohol is especially preferable among alcohol.

  As a method for impregnating the reinforcing sheet-like material (B) with the polyamide resin (A) dissolved in alcohol, the reinforcing sheet-like material (B) is placed in a container containing the polyamide resin (A) dissolved in alcohol. A method of dipping and removing, a method of applying a polyamide resin (A) dissolved in alcohol to a roller and applying it to a reinforcing sheet (B), or a container containing a reinforcing sheet (B) And a method of sucking and impregnating the polyamide resin (A) dissolved in alcohol using a vacuum pressure is not particularly limited.

  Examples of a method for setting the polyamide resin content in the structure to 5 to 15% by weight include a method of setting the polyamide resin concentration in the alcohol to about 10 to 30% by weight, and the thickness of the structure before the alcohol volatilization treatment. There is a method for adjusting the value, but it is not particularly limited.

  The resin content in the structure is defined by the following formula.

    Resin content (% by weight) = (C−D) / D × 100.

Where C: the weight of the structure 30 minutes after the alcohol volatilization treatment,
D: The weight of the reinforcing sheet before impregnation treatment.

  The method for volatilizing alcohol is not particularly limited as long as it is heated in the container or outside the container with an oven or a heater during or after the impregnation.

  In addition, since the structure of the present invention contains a polyamide resin, a decrease in strength due to water absorption should be taken into consideration, and the water absorption measurement of the structure is defined by the following equation.

    Water absorption (% by weight) = (E−F) / F × 100.

However, E: weight of the structure after being left in the atmosphere at 20 ° C. and 65% RH for 48 hours,
F: The weight after the structure of E is vacuum-dried at 80 ° C. for 12 hours.

(Example 1)
Alcohol-soluble polyamide resin (Toray nylon resin: CM4000) was dissolved in 70% methanol at 10% by weight and impregnated into a reinforcing sheet. As the reinforcing sheet-like material, a 70 mm × 70 mm carbon fiber cloth C06343 (apparent thickness: 0.25 mm) by Toray Industries, Inc. “Torayca” was used.

  After impregnating the above-mentioned reinforcing resin sheet in methanol with the polyamide resin, the coating thickness was adjusted to 0.26 mm with a slit bar and methanol was volatilized in an oven at 60 ° C. The rate was 14% by weight.

(Example 2)
An alcohol-soluble polyamide resin (Toray nylon resin: CM831) was dissolved in 70% methanol at 10% by weight and impregnated into a reinforcing sheet. The same carbon fiber cloth as in Example 1 was used for the reinforcing sheet.

  After impregnating the above-mentioned reinforcing resin sheet in methanol with the polyamide resin, the coating thickness was adjusted to 0.26 mm with a slit bar and methanol was volatilized in an oven at 60 ° C. The rate was 13% by weight.

(Comparative Example 1)
The polyamide resin (Toray nylon resin: CM4000) shown in Example 1 was dissolved so as to be 10% by weight with respect to methanol at 70 ° C., and this was impregnated into a reinforcing sheet. The same carbon fiber cloth as in Example 1 was used for the reinforcing sheet.

  After impregnating the above-mentioned reinforcing resin sheet in methanol with the polyamide resin, the coating thickness was adjusted to 0.28 mm with a slit bar, and methanol was volatilized in an oven at 60 ° C. The rate was 25% by weight. However, it was confirmed that the strength and rigidity of the entire structure were lowered due to the water absorption characteristics of the nylon resin.

(Comparative Example 2)
The polyamide resin (Toray nylon resin: CM831) shown in Example 2 was dissolved so as to be 10% by weight with respect to methanol at 70 ° C., and this was impregnated into a reinforcing sheet. The same carbon fiber cloth as in Example 1 was used for the reinforcing sheet.

  After impregnating the above-mentioned reinforcing resin sheet in methanol with the polyamide resin, the coating thickness was adjusted to 0.28 mm with a slit bar, and methanol was volatilized in an oven at 60 ° C. The rate was 24% by weight. However, as in Comparative Example 2, it was confirmed that the strength and rigidity of the entire structure were lowered due to the water absorption characteristics of the nylon resin.

(Comparative Example 3)
The polyamide resin (Toray nylon resin: CM4000) shown in Example 1 was dissolved so as to be 10% by weight with respect to methanol at 70 ° C., and this was impregnated into a reinforcing sheet. The same carbon fiber cloth as in Example 1 was used for the reinforcing sheet.

  After impregnating the above-described reinforcing resin-like methanol solution into the reinforcing sheet-like material, the coating thickness was adjusted to 0.255 mm with a slit bar, and the methanol was volatilized in an oven at 60 ° C. The rate was 3.9% by weight. However, since the structure has a low resin content, the shape could not be maintained, and fraying of the carbon fibers was confirmed.

(Comparative Example 4)
As the reinforcing sheet material, the same carbon fiber cloth as in Example 1 was used for the reinforcing sheet material, which was placed in a mold having a cavity of 80 mm × 80 mm × thickness 1 mm, and polyamide 6 resin (Toray nylon resin: CM1017) was injection molded. However, when the inside of the structure was observed, the polyamide 6 resin was not impregnated inside the carbon fiber cloth, and fraying was partially confirmed.

  From the examples and comparative examples, it can be seen that the structure and the manufacturing method of the present invention can be reduced in weight by reducing the amount of impregnated resin as compared with the prior art, and a structure having stable mechanical properties can be easily obtained. .

  The structure and the manufacturing method according to the present invention can easily obtain a structure having light weight and stable mechanical properties by using a specific polyamide resin composition and a widely known solvent such as alcohol and water. The resulting structure is widely used in the aerospace field, automobile parts and general industrial fields.

Claims (3)

It is a structure formed by impregnating a reinforcing sheet-like material (B) with an alcohol-soluble polyamide resin (A), and the polyamide resin (A) content of the structure is 5 to 15 based on the weight of the structure A structure characterized by the weight percent. The structure according to claim 1, wherein the reinforcing sheet-like material (B) contains one or more selected from glass fiber, carbon fiber, aramid fiber, and polyamide fiber. A method for producing a structure, comprising: dissolving the polyamide resin (A) according to claim 1 in alcohol; then impregnating the reinforcing sheet (B); and volatilizing the alcohol.