JP2003342381A - Method for producing fiber reinforced phenolic resin molded product and fiber reinforced phenolic resin molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber reinforced phenolic resin (phenolic FRP) which has high strength and excels in heat resistance, flame resistance and the like, and a phenolic FRP molded product having the above properties obtained by this method. <P>SOLUTION: The method for producing the phenolic FRP molded product comprises impregnating a fiber reinforcing material with a liquid material comprising a resol type phenolic resin obtained by mixing (A) a resol type phenolic resin solution containing 2-15 wt.% free formaldehyde with (B) a resol type phenolic resin solution containing 15-60 wt.% resorcinal and, based on 100 pts.wt. resol type phenolic resin, 3-18 pts.wt. free formaldehyde and 1-40 pts.wt. resorcinal, and heat curing the impregnated fiber reinforced material. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a fiber-reinforced phenolic resin (hereinafter referred to as phenol FRP) molded article. More specifically, the present invention relates to a method for producing a phenol FRP molded product having a higher strength than that of a conventional phenol FRP molded product, and a high-strength phenol FRP molded product obtained by the method.

[0002]

2. Description of the Related Art In recent years, phenol FRP moldings have not been obtained with thermosetting resin FRP moldings such as unsaturated polyester resin and epoxy resin, or thermoplastic resin FRP moldings such as polypropylene resin, polyethylene resin and polystyrene resin. Since it has various excellent properties such as heat resistance, flame resistance, and low smoke generation, its usefulness has received a great deal of attention. Recently, the application of phenol FRP moldings to structural materials has also been investigated. However, in the case of impregnating glass fiber with a conventional resol-type phenolic resin and thermally curing it, it is the present situation that the desired strength cannot be obtained due to influence of gas generated during curing and poor compatibility with glass fiber. In order to apply it to building structural materials, it is required to have higher strength while maintaining heat resistance and flame resistance.

By the way, as a technique of a phenol FRP molded article using resorcin, a method of preparing a phenol resin and a resorcinol resin separately and mixing them is disclosed (JP-A-2-215879). , JP-A-7-60928). However, in all of these, novolak, which is a resorcinol resin component synthesized with resorcin and formaldehyde using an acid catalyst, is used, and since this is basically a solid or semi-solid, it is necessary to dilute it to make it a liquid. A chemical agent is required, and as a result, physical properties and flame resistance may be adversely affected. In addition, there is a concern that the acid catalyst residue (salt, etc.) may corrode the metal.

Further, a technique has been disclosed in which a resole-type phenol resin is prepared using an alkali catalyst, then resorcinol and formaldehyde are added and reacted in two steps, and paraformaldehyde is used as a curing agent. No. 192360), and rapid curing is possible at a low temperature of 70 to 110 ° C. However, it is suggested that a mold temperature higher than 110 ° C. causes unevenness on the molding surface. Although the cross-linking reaction of the resorcinol resin proceeds even at a relatively low temperature, complete curing cannot be expected in the condensation reaction of the resole-type phenol resin in the above temperature range, and post cure at a high temperature (125 ° C. in the example) is required. In addition, the curing tends to be non-uniform, and as a result, there is concern that the characteristics may deteriorate.

[0005]

Under the circumstances, the present invention provides phenol FR which has high strength, excellent heat resistance and flame resistance, and is easily applied to building structural materials.
It is an object of the present invention to provide a method for producing a P molded product and a phenol FRP molded product having the above characteristics obtained by this method.

[0006]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that a resole-type phenol resin solution containing free formaldehyde and a resole-type phenol resin solution containing resorcins are obtained. Obtained by mixing, when the resin composition consisting of a liquid material containing a resol type phenol resin, free formaldehyde and resorcins in a specific ratio is impregnated into the fiber reinforcement and heat-cured, it is contained in the resin. Since free formaldehyde and resorcins react around the fiber reinforcement,
It has been found that a phenol FRP molded article having a high strength obtained by strongly bonding the fiber reinforcing material and the resin can be obtained, and that the object can be achieved. The present invention has been completed based on such findings.

That is, according to the present invention, (1) (A) a resole type phenol resin solution containing 2 to 15% by weight of free formaldehyde and (B) a resole type phenol resin solution containing 15 to 60% by weight of resorcins are mixed. The fiber reinforced material is impregnated with a resin composition comprising a resol-type phenol resin obtained by the above, and a liquid material containing 3 to 18 parts by weight of free formaldehyde and 1 to 40 parts by weight of resorcins per 100 parts by weight thereof. A method for producing a fiber-reinforced phenolic resin molded article, which comprises heat curing by
(2) In the component (B), the method for producing the fiber-reinforced phenolic resin molded product according to (1) above, wherein the content of free formaldehyde in the resole-type phenolic resin liquid before mixing and dissolving the resorcins is 5% by weight or less. , (3) the resin solid content in the resol-type phenolic resin liquid of (A) is 6
0 to 85% by weight of the method for producing a fiber-reinforced phenolic resin molding according to the above (1) or (2), (4) in the component (B), in the resole-type phenolic resin liquid before mixing and dissolving resorcins 120 to 200 by the method for producing a fiber-reinforced phenolic resin molded product according to any one of (1) to (3) above, which has a resin solid content of 40 to 80% by weight, and (5) a pultrusion molding method or a filament winding molding method.
Obtained by the method for producing a fiber-reinforced phenolic resin molded product according to any one of (1) to (4) above, which is heat-cured at a temperature of ° C, and (6) any one of the above methods (1) to (5). A fiber-reinforced phenolic resin molded product is provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for producing a phenol FRP molded article according to the present invention, the resin composition used by impregnating the fiber reinforced material is a liquid material containing a resol type phenol resin, free formaldehyde and resorcins. Is. In the resin composition, the free formaldehyde is 3 to 100 parts by weight of the resol type phenol resin.
The content of resorcinol is 1 to 4
It is contained in the range of 0 parts by weight. When the content of the free formaldehyde is less than 3 parts by weight, the reaction with resorcins is small, so that the curing may be delayed, and when it exceeds 18 parts by weight, the pot life tends to be shortened, and the molded product is also formed. The amount of free formaldehyde in the product increases, which is not preferable in terms of environmental hygiene. The more preferable content of the free formaldehyde is in the range of 4 to 10 parts by weight.

On the other hand, if the content of the resorcins is less than 1 part by weight, the mechanical strength of the molded product is not sufficiently improved, and if it exceeds 40 parts by weight, the resorcins are completely contained in the resol type phenol resin solution. It becomes difficult to dissolve it. The preferable content of the resorcins is in the range of 5 to 15 parts by weight. Examples of the resorcins include resorcin, alkyl-substituted resorcin, and alkoxy-substituted resorcin. These may be used alone or in combination of two or more. The total concentration of the resole type phenolic resin and the resorcins in the resin composition used in the present invention is not particularly limited as long as a viscosity suitable for impregnating the fiber reinforcement is obtained, but is usually 50 to 90 weight. %, Preferably 60 to
It is in the range of 85% by weight.

In the method of the present invention, a resin composition containing free formaldehyde and resorcins together with such a resole type phenolic resin is (A) a resol type phenolic resin liquid containing 2 to 15% by weight of free formaldehyde. B) It is necessary to prepare by mixing with a resole-type phenol resin solution containing 15 to 60% by weight of resorcins, and it is necessary to simply add free formaldehyde and resorcins to the resole-type phenol resin solution and the above content ratio. If you adjust to, you can not get the desired effect.

The resol type phenol resin solution in the components (A) and (B) can be obtained by a conventionally known method, that is, by reacting phenols with formaldehyde in the presence of an alkali catalyst. Here, as the phenols, for example, phenol, cresols, xylenols, butylphenols, p-
Methoxyphenol, bisphenol A, bisphenol F, etc. may be mentioned, and these may be used alone or in combination of two or more.

On the other hand, examples of the alkali catalyst include metal hydroxides, metal oxides, metal salts and amino compounds containing amino groups. Specific examples thereof include sodium hydroxide, ammonium hydroxide, and hydroxide. Potassium, calcium hydroxide, barium hydroxide, magnesium hydroxide,
Magnesium oxide, calcium oxide, sodium oxide,
Potassium oxide, zinc acetate, lead acetate, triethylamine,
Hexamethylenetetramine, dimethylethanolamine, ammonia and the like are exemplified. These alkali catalysts may be used alone or in combination of two or more.

Regarding the mixing ratio of the above-mentioned components (A) and (B), the content of free formaldehyde and resorcins in the obtained resin composition may be within the above range with respect to the resole type phenol resin. , There is no particular limitation. In the component (B), the content of free formaldehyde in the resol type phenol resin solution before mixing and dissolving the resorcins is preferably adjusted to 5% by weight or less. If the content of free formaldehyde exceeds 5% by weight, the reaction between resorcinols and formaldehyde proceeds, and the viscosity of the reaction product increases rapidly due to the influence of the reaction product.
This causes deterioration of storage stability of the component (B) itself. Furthermore, the resin solid content in the resol type phenolic resin liquid of the component (A) is preferably 60 to 85% by weight, and the resole type phenolic resin liquid before mixing and dissolving the resorcins in the component (B). The resin solid content in the
It is preferably 40 to 80% by weight. If the resin solid content is less than these ranges, physical properties such as strength of the molded product may be deteriorated, and if the resin solid content exceeds these ranges, the viscosity of the resin liquid itself becomes high, and there is a risk of poor mixing when mixing both components. is there.

In the method for producing a phenol FRP molded article of the present invention, the resin composition thus obtained is impregnated into the fiber reinforced material and heat cured, but the components (A) and (B) are combined. When left in a mixed liquid state for a long time, the reaction between resorcins and formaldehyde proceeds,
Since the effects of the present invention may not be sufficiently obtained, it is preferable to impregnate the fiber reinforcement within 24 hours after mixing. This resin composition is usually 120 to 20.
It can be thermoset at temperatures in the range of 0 ° C. Also,
When using a general pultrusion machine, the mold temperature is 150
Molding is possible at about 200 ° C. If necessary, the resin composition may be mixed with various additives that are conventionally used in phenolic resin compositions conventionally used for phenol FRP molded products. Examples of the additive include fillers such as calcium carbonate, clay, talc, aluminum hydroxide, barium sulfate and calcium sulfate, and release agents such as metal soaps and waxes.

Examples of the fiber reinforcement used in the production method of the present invention include chopped strand mats, continuous mats, rovings made of synthetic fibers such as glass fibers, carbon fibers, or aramid fibers.
Examples include roving cloth and blind cloth. Further, as various fiber reinforcing materials, those subjected to usual surface treatment such as silane treatment and boron treatment can be used.

As the molding method, various conventionally known molding methods such as filament winding (FW) can be used.
Method, resin injection (RTM) method, drawing (P
L) method, SMC method, etc. can be adopted, but among these molding methods, it is preferable to use a drawing method or a filament winding method and cure at a temperature of about 120 to 200 ° C. In the present invention, the free formaldehyde contained in the resin component reacts with the resorcins during the heat curing, and the resorcinol resin having excellent adhesiveness is efficiently used, and the fiber reinforced material and the resole type phenol resin are efficiently formed around the fiber reinforced material. It seems to be formed in a conforming manner. As a result, the obtained phenol FRP molded product is excellent in mechanical strength, heat resistance, flame resistance and the like, and in particular, the mechanical strength is significantly improved as compared with the conventional one.

[0017]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. Production Example 1 A mixture of 100 parts by weight of phenol, 123 parts by weight of a 37% by weight aqueous formalin solution and 2.0 parts by weight of zinc acetate hydrate was heated at 100 ° C. for 3 hours to cause reaction, and then dehydrated under reduced pressure to form free formaldehyde. 2.5% by weight, 2
5 ° C viscosity 6,000 mPa · s, resin solid content 74
150 parts by weight of a resol type phenol resin solution I having a weight percentage of 50% was obtained.

Production Example 2 A mixture of 100 parts by weight of phenol, 170 parts by weight of 37% by weight formalin aqueous solution and 2.0 parts by weight of zinc acetate hydrate was heated at 100 ° C. for 3 hours to cause reaction, and then dehydrated under reduced pressure. Has a free formaldehyde content of 13.4% by weight,
25 ° C viscosity 5,500 mPa · s, resin solid content 7
155 parts by weight of 0% by weight of resol type phenol resin solution II was obtained.

Production Example 3 A mixture of 100 parts by weight of phenol, 150 parts by weight of a 37% by weight formalin aqueous solution and 2.0 parts by weight of sodium hydroxide was heated at 80 ° C. for 2 hours to cause a reaction, and then dehydrated under reduced pressure to liberate. Formaldehyde content 3.5% by weight, 25
160 parts by weight of a resol type phenolic resin liquid III having a viscosity of 4,000 mPa · s and a resin solid content of 73% by weight was obtained.

Production Example 4 A mixture of 100 parts by weight of phenol, 108 parts by weight of 37% by weight aqueous formalin solution and 8 parts by weight of sodium hydroxide was added,
After heating at 70 ° C. for 3 hours to cause reaction, the reaction product was dehydrated under reduced pressure to obtain 150 parts by weight of a resol type phenol resin solution having a free formaldehyde content of 0.6% by weight and a resin solid content of 69% by weight. It was The polystyrene-reduced weight average molecular weight of the resol-type phenol resin was 150. Then, 20 parts by weight of resorcin was added to 100 parts by weight of this resole type phenol resin solution, and the mixture was mixed at 35 ° C. for 3 hours.
Dissolve with stirring for 0 minutes and the viscosity at 25 ° C is 500 mPa · s, p
120 parts by weight of H8.0 resol type phenol resin solution IV was obtained.

Production Example 5 A mixture of 100 parts by weight of phenol, 125 parts by weight of a 37% by weight aqueous formalin solution, and 8 parts by weight of sodium hydroxide was added.
After heating at 70 ° C. for 3 hours for reaction, the reaction product was dehydrated under reduced pressure to obtain 150 parts by weight of a resol-type phenol resin solution having a free formaldehyde content of 1.5% by weight and a resin solid content of 67% by weight. It was The polystyrene-reduced weight average molecular weight of the resol-type phenol resin was 150. Next, 80 parts by weight of resorcin was added to 100 parts by weight of this resol type phenol resin solution, and the mixture was mixed at 35 ° C. for 3 days.
Dissolve with stirring for 0 minutes, and the viscosity at 25 ° C is 900 mPa · s, p
180 parts by weight of H7.5 resol type phenol resin solution V was obtained.

Example 1 Resol type phenol resin solution I: 100 parts by weight, resol type phenol resin solution IV: 5 parts by weight, 20 parts by weight of clay and 2 parts by weight of a releasing agent are mixed to prepare a resin composition. The pot life of this resin composition (time until the resin composition loses fluidity at 40 ° C.) was measured. Next, a glass fiber material was impregnated with the above resin composition, and a board having a thickness of 3 mm and a width of 300 mm was molded using a pultrusion molding machine. At that time, the temperature of the mold was 200 ° C., and the drawing speed was 20 cm / min. The mechanical properties of the board were measured, and the result was measured along with the pot life to
Shown in the table. The time from the mixing of the resol type phenol resin solution I and the resol type phenol resin solution IV to the impregnation of the glass fiber material was 7 hours.

Examples 2 to 5 A resin composition having the composition shown in Table 1 was prepared, and Example 1 was prepared.
A board was molded in the same manner as in. The pot life of the resin composition and the mechanical properties of the board are shown in Table 1.

Comparative Example 1 As a conventional resole resin, "BRL-240" (trade name, manufactured by Showa Highpolymer Co., Ltd.) was used to prepare a resin composition having the composition shown in Table 1, and an example was prepared. Boards were molded as in 1. The pot life of the resin composition and the mechanical properties of the board are shown in Table 1.

Comparative Examples 2 and 3 A resin composition having the composition shown in Table 1 was prepared, and Example 1 was prepared.
A board was molded in the same manner as in. The pot life of the resin composition and the mechanical properties of the board are shown in Table 1.

[0026]

[Table 1]

[0027]

[Table 2]

[Note] Release agent: Moldwith JNT-1850HT (trade name, manufactured by Axel) Compressive strength: JIS K 7056 Bending strength: JIS K 7055 Bending elastic modulus: JIS K 7055 Tensile strength: JIS K 7054 Tensile modulus: JIS K 7054

[0029]

According to the method of the present invention, it is possible to produce a phenol FRP molded product having higher strength and excellent mechanical properties as compared with the conventional phenol FRP molded product.

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Claims (6)

[Claims] 1. A mixture of (A) a resole type phenol resin solution containing 2 to 15% by weight of free formaldehyde and (B) a resole type phenol resin solution containing 15 to 60% by weight of resorcins, A resin composition composed of a resole-type phenol resin and a liquid material containing 3 to 18 parts by weight of free formaldehyde and 1 to 40 parts by weight of resorcin per 100 parts by weight thereof is impregnated into a fiber reinforced material and thermally cured. And a method for producing a fiber-reinforced phenolic resin molded product. 2. In the component (B), the content of free formaldehyde in the resol type phenol resin solution before mixing and dissolving resorcins is 5% by weight or less.
A method for producing the fiber-reinforced phenolic resin molding described. 3. The resin solid content in the resol type phenolic resin liquid of the component (A) is 60 to 85% by weight.
Or the method for producing a fiber-reinforced phenolic resin molded article according to item 2. 4. The fiber reinforced according to claim 1, wherein the component (B) has a resin solid content of 40 to 80% by weight in the resol type phenol resin solution before mixing and dissolving the resorcins. Method for producing phenolic resin molded product. 5. The method for producing a fiber-reinforced phenolic resin molded product according to claim 1, which is heat-cured at a temperature of 120 to 200 ° C. by a pultrusion molding method or a filament winding molding method. 6. A fiber-reinforced phenolic resin molded product obtained by the method according to claim 1.