JP6322097B2 - Thermosetting furan resin composition and furan resin laminate using the same - Google Patents

Description

  The present invention relates to a thermosetting furan resin composition and a furan resin laminate using the same.

Furan resin is used in various industrial fields as a matrix resin for composite materials such as steel pipe lining, medge cement, and fiber reinforced plastic (FRP) because its cured product has excellent heat resistance, solvent resistance, and chemical resistance. ing.
Therefore, in a thermosetting furan resin composition containing a furan resin and a curing catalyst composed of an ammonium salt or an amine, a composition that keeps storage stability at normal temperature, so-called pot life long has been proposed (Patent Literature). 1).

  However, this composition does not use a curing agent as a reaction initiator and is a composition intended for heat curing only with a curing catalyst, so that the pot life at room temperature is sufficient, but sufficient curing is achieved. There was a problem that the bending elastic modulus of the cured product was insufficient.

  Moreover, the thermosetting furan resin composition which consists of furan resin, a hardening | curing agent, and a curing catalyst is proposed (patent document 2). In the cured product using this composition, the creep performance can be improved, but since a large amount of the curing agent is used in the composition, the storage stability of the composition itself at room temperature, so-called pot life is short, and the long pot It was difficult to achieve life.

JP 2012-17349 A JP 2013-91077 A Specification

  The present invention has been made in view of the above problems, and provides a thermosetting furan resin composition and a furan resin laminate capable of realizing a long pot life of the composition itself while ensuring sufficient bending elastic modulus in the cured product. The purpose is to provide.

  The present invention is a thermosetting furan resin composition comprising a furan resin, a curing agent and a curing catalyst, wherein the curing catalyst is a bromide amine salt or an ammonium bromide salt. .

According to the thermosetting furan resin composition of the present invention, a long pot life of the composition itself can be realized.
Moreover, according to hardened | cured materials, such as a furan resin laminated body using this, the impregnation property of a furan resin composition becomes favorable with a long pot life, and sufficient bending elastic modulus can be ensured in hardened | cured material.

  The thermosetting furan resin composition in the present invention mainly contains a furan resin, a curing agent and a curing catalyst.

(Furan resin)
The furan resin used in the present invention is not particularly limited as long as it is a furan resin. Furfuryl alcohol condensed furan resin, furfuryl alcohol / phenol condensed furan resin, furfuryl alcohol / aldehyde condensed furan resin, epoxy-modified furan resin , Urea-modified furan resin, melamine-modified furan resin, phenol-modified furan resin, aldehyde-modified furan resin, and the like. These may be used alone or in combination of two or more.

  When the thermosetting furan resin composition is cured, the furan resin preferably has a water content of 10% by weight or less, and preferably 9% by weight or less, in order to minimize dimensional shrinkage due to moisture dissipation. Less than 3% by weight, more preferably 2% by weight or less, and further preferably 1% by weight or less.

(Curing agent)
The curing agent used in the present invention is not particularly limited as long as it can cure the furan resin, and examples thereof include inorganic acids and organic acids.
Examples of inorganic acids include hydrochloric acid and sulfuric acid.
Organic acids include xylene sulfonic acid, toluene sulfonic acid, phenol sulfonic acid, p-toluene sulfonic acid, benzene sulfonic acid, methane sulfonic acid and other organic sulfonic acids; malonic acid, succinic acid, maleic acid, oxalic acid, acetic acid, lactic acid And organic carboxylic acids such as malic acid, tartaric acid, benzoic acid and citric acid.

  The content of the curing agent can be appropriately adjusted according to the type and dilution concentration of the furan resin and the curing catalyst, the target curing temperature, the curing time, and the like. For example, 0.1 to 5 parts by weight and 0.5 to 1.5 parts by weight are preferable with respect to 100 parts by weight of furan resin, and 0.7 to 1.0 parts by weight is particularly preferable. By setting within this range, it is possible to ensure a long pot life on the other hand without causing poor curing.

(Curing catalyst)
Examples of the curing catalyst used in the present invention include ammonium bromide salts and bromide amine salts. Specific examples include ammonium bromide, ethyl bromide, dimethylamine bromide, methylamine bromide and the like. These may be used alone or in combination of two or more.

  Ammonium bromide salt and amine bromide salt are dissociated into ammonia or amine and free acid by reaction with formaldehyde contained in a small amount in furan resin, and the furan resin is cured by the free acid. Since the acid generated from the ammonium bromide salt or the amine bromide salt has a small pKa and a high acid strength, curing can be promoted with a small amount. In addition, ammonium bromide salts and amine bromide salts have high solubility in water, and can reduce the amount of water in the thermosetting furan resin composition. Thereby, shrinkage | contraction and the fall of intensity | strength of the thermosetting furan resin composition by a water | moisture content can be suppressed.

  The content of the curing catalyst can be adjusted as appropriate depending on the type of furan resin and curing catalyst used, the desired flexural modulus and pot life. For example, 0.5 to 5.0 parts by weight and 0.8 to 4.0 parts by weight are preferable with respect to 100 parts by weight of furan resin, and 1.0 to 3.2 parts by weight are more preferable. By setting it in this range, a sufficient bending elastic modulus can be obtained in the cured product of the thermosetting furan resin composition, and shrinkage during the curing can be suppressed.

In the thermosetting furan resin composition of the present invention, it is preferable to use only the above-mentioned curing catalyst as the curing catalyst. However, in addition to the above-mentioned curing catalyst, other ammonium salt or amine salt is included. May be.
Examples of the ammonium salt include ammonium chloride, ammonium sulfate, ammonium nitrate, and ammonium acetate.
Examples of the amine salt include hydrochlorides such as methylamine hydrochloride, dimethylamine hydrochloride, ethylamine hydrochloride and diethylamine hydrochloride, and mineral salts such as sulfate.
These may be used alone or in combination of two or more.
The ammonium salt and amine salt are preferably dissolved or dispersed in a diluent to facilitate addition and dispersion to the furan resin. Diluents include alcohols such as water, methanol, and furfuryl alcohol.

  In the case of other ammonium salts and amine salts, during heat curing, ammonia or amine dissociated by heating reacts with formaldehyde contained in a small amount in the furan resin to form an amine compound and stabilize. Further, the acid component is liberated and the furan resin is rapidly cured by the free acid. Therefore, it is possible to achieve both shortening of the curing time and prolonging the pot life.

  When other ammonium salts and amine salts are included, the total content of the curing catalyst is, for example, preferably 0.3 to 10 parts by weight and more preferably 0.3 to 5 parts by weight with respect to 100 parts by weight of the furan resin. 0.5 to 5 parts by weight, 0.8 to 4.0 parts by weight are preferable, and 1.0 to 3.2 parts by weight are more preferable. By setting within this range, it is possible to ensure a long pot life on the other hand without causing poor curing.

(Inorganic filler)
The thermosetting furan resin composition may further contain an inorganic filler. By containing such an inorganic filler, the strength of the thermosetting furan resin composition after curing can be improved.
As the inorganic filler, those having a high elastic modulus and capable of high filling are preferable, and from the viewpoint of preventing curing inhibition, an inorganic filler having a pH of 10 or less is preferable. Specific examples include glass powder, silica, talc, kaolin, mica, and aluminum hydroxide. Of these, kaolin, silica, aluminum hydroxide and the like are preferable from the viewpoint of cost.

  The inorganic filler is preferably subjected to a surface treatment. The surface treatment agent is not particularly limited as long as it can react or bond with the inorganic filler and the furan resin, and examples thereof include organosilane surface treatment agents. Specifically, examples of the organic silane surface treatment agent include an aminosilane surface treatment agent, an epoxysilane surface treatment agent, and an acrylic silane surface treatment agent. By using the inorganic filler subjected to such a surface treatment, the interfacial adhesive force between the furan resin and the inorganic filler can be improved. As a result, the hardness can be further improved.

  The content of the inorganic filler can be appropriately adjusted depending on the viscosity of the furan resin. For example, the amount is preferably 10 to 200 parts by weight, more preferably 20 to 150 parts by weight, and still more preferably 30 to 100 parts by weight with respect to 100 parts by weight of the furan resin. By setting to this range, an appropriate viscosity of the thermosetting furan resin composition can be ensured, and the impregnation property to the substrate can be improved. Furthermore, strength characteristics can be improved.

(Inorganic additive)
The thermosetting furan resin composition may further contain an inorganic additive. The inorganic additive is preferably a water-soluble compound. For example, sodium chloride, lithium chloride, sodium bromide, lithium bromide, etc. are mentioned. These may be used alone or in combination of two or more. Here, the water-soluble is not particularly limited as long as it is soluble in water, but the amount of the compound dissolved in 100 g of water at 20 ± 5 ° C. is preferably 1 g or more, and more preferably several g or more. . Even if the inorganic additive is hardly soluble in water, depending on the content and moisture content of the inorganic additive in the thermosetting furan resin composition, the inorganic additive in the thermosetting furan resin composition The additive is preferably in the form of an aqueous solution (a form dissociated into ions).

The type and content of the inorganic additive can be appropriately adjusted depending on the furan resin, the type of curing catalyst, the moisture content, dimensional accuracy, and the like. Of these, lithium chloride is preferred as the inorganic additive because of its dimensional change prevention effect and high solubility at room temperature.
For example, the content of the inorganic additive is preferably 0.2 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, and still more preferably 1 to 3 parts by weight with respect to 100 parts by weight of the furan resin. By setting within this range, a sufficient effect of preventing dimensional change can be obtained, and the thermosetting furan resin composition can be adjusted to an appropriate viscosity.

(Other ingredients)
The thermosetting furan resin composition of the present invention may contain additives known in the art as needed, as long as the object of the present invention is not impaired. Examples of the additive include a plasticizer, a foam stabilizer, a reactive diluent, a moisture scavenger and the like.

  Examples of the plasticizer include phthalic acid esters such as diethyl phthalate and dibutyl phthalate, phosphoric acid esters, fatty acid esters, and epoxy plasticizers. These may be used alone or in combination of two or more.

  Examples of the foam stabilizer include castor oil, castor oil derivatives, polysiloxane compounds, and polyoxyethylene sorbitan fatty acid esters. These may be used alone or in combination of two or more.

The reactive diluent is usually used for viscosity adjustment or reactivity adjustment. The reactive diluent is not particularly limited as long as it has a low viscosity, is compatible with the furan resin, and exhibits reactivity when the thermosetting furan resin composition is cured. For example, furfuryl alcohol, Examples include furfural and a mixture thereof.
The content of the reactive diluent can be appropriately adjusted depending on the type of the reactive diluent and the viscosity of the furan resin, and is preferably 10 to 130 parts by weight with respect to 100 parts by weight of the furan resin. 110 parts by weight is more preferable. By setting this range, it is possible to sufficiently and moderately impregnate the laminate described later.

The moisture trapping agent is not particularly limited as long as it can trap moisture, and examples thereof include those capable of trapping moisture by hydration of inorganic salts or those capable of trapping moisture by adsorption at intramolecular pores. Examples of the former include anhydrous sodium sulfate, anhydrous magnesium sulfate, anhydrous copper sulfate, and calcium chloride. Examples of the latter include silica gel, molecular sieve, zeolite and the like.
The content of the moisture scavenger is preferably 1 to 100 parts by weight with respect to 100 parts by weight of the furan resin, for example.

(Method for producing thermosetting furan resin composition)
A thermosetting furan resin composition can be manufactured by adding and mixing a curing agent and a curing catalyst simultaneously or in any order to a furan resin. Moreover, you may add and mix another component at the arbitrary time of this addition and mixing. For example, it is preferable to contain 0.1 to 5 parts by weight of a curing agent and 0.5 to 5.0 parts by weight of a curing catalyst with respect to 100 parts by weight of a furan resin, and 0.5 to 1.5 parts by weight of the curing agent. And 0.8 to 4.0 parts by weight of the curing catalyst, or 0.5 to 1.5 parts by weight of the curing agent and 1.0 to 3.2 parts by weight of the curing catalyst are more preferable. More preferably, 0.7 to 1.0 part by weight and 1.0 to 3.2 parts by weight of the curing catalyst are contained.

  Such a thermosetting furan resin composition can be used, for example, to impregnate the resin composition, invert or retract the laminated body, in order to form a furan resin laminated body using reinforcing fibers, depending on the application. In order to secure the working time, for example, a pot life of 2 hours or more, preferably 5 hours or more, more preferably 12 hours or more can be provided.

In the thermosetting furan resin composition, for example, the viscosity at 25 ° C. is preferably adjusted to 400 to 7000 mPa · s. By setting this range, for example, when the thermosetting furan resin composition is used as the base resin of the fiber reinforced resin, the resin composition can be sufficiently permeated into the fiber, and due to gravity or the like in the glass fiber. Uneven distribution can be prevented.
The viscosity of the thermosetting furan resin composition is adjusted by selecting the type and combination of materials, adding a reactive diluent in an appropriate amount, adding an anti-crystallization agent, and a filler. be able to.

(Furan resin laminate)
The furan resin laminate can be produced by impregnating the above-described thermosetting furan resin composition into a laminate containing reinforcing fibers and curing.
The reinforcing fiber is not particularly limited, and examples thereof include glass fiber, aramid fiber, carbon fiber, inorganic fiber, organic fiber, whisker and the like, or combinations thereof. Especially, glass fiber is preferable from the balance of the intensity | strength and price of the furan resin laminated body obtained. The reinforcing fiber preferably has a fiber diameter in the range of 3 to 25 μm, and more preferably 5 to 20 μm from the viewpoints of strength and price.

  A laminated body may be comprised only from a reinforced fiber, and may be comprised including other members, such as a binder and another base material. As a base material, what is necessary is just a base material which can impregnate a thermosetting furan resin composition, for example, the base material whose porosity is 90% or less is mentioned. Thereby, the malfunction that a void etc. are formed in the base material after hardening of a thermosetting furan resin composition can be suppressed to the minimum. For example, such a substrate preferably has a thickness of 3 mm or more. It is because sufficient protective properties can be expressed. Examples of the substrate include a single layer such as a nonwoven fabric and a chopped strand mat, or a laminated structure of different materials.

Examples of the nonwoven fabric include resins such as polyester, high-density polyethylene (HDPE), and polypropylene, and natural materials such as cotton, linseed, flax burlap, and kenaf, and those made of a material having high strength and high elasticity are preferable. Especially, what consists of resin is more preferable. Also, felt, mat, spunbond, web, etc. that are flexible and porous and have continuous filaments or staple fibers can be used.
As a chopped strand mat, for example, after strands are cut into a certain length and dispersed in a mat shape, an adhesive such as a thermoplastic resin is uniformly applied and heat-melted to bond the strands together. Mattes and the like can be mentioned.

The laminated body is preferably formed by laminating a plurality of layers of reinforcing fibers and other members in various forms such as a thread form, a sheet form, a woven form, and a knitted form.
Depending on the application, one surface of the laminate may be liquid-tightly film-coated. For example, what the one surface has arrange | positioned the water-impermeable film or the water-impermeable layer is mentioned. The water-impermeable film and the water-impermeable layer are made of, for example, a synthetic resin material such as polyethylene, polypropylene, nylon, polyester, polyvinyl chloride, elastomer, and synthetic rubber with a thickness of about 0.2 to 2.0 mm or The sheet can be formed by coating reinforcing fibers or other members.

  The method of impregnating the laminate with the thermosetting furan resin composition is not particularly limited. For example, the method of impregnating the laminate with the thermosetting furan resin composition using an impregnation roll, the thermosetting furan resin. Examples include a method of impregnating the laminate in a container containing the composition.

The method for curing the thermosetting furan resin composition impregnated in the laminate is not particularly limited, for example, a method in which hot air is blown to the thermosetting furan resin composition impregnated in the laminate and cured. A method of pouring the thermosetting furan resin composition into the resin and heating and curing it using hot air or hot water, or by sandwiching it in a hot plate, and the like.
For example, the curing temperature is preferably 70 to 130 ° C, more preferably 60 to 100 ° C. The curing time is preferably maintained at the curing temperature for about 1 hour or more, for example.
By such curing, the furan resin laminate can realize excellent characteristics with a dimensional retention of 99% or more after curing at 25 ° C. (humidity 50%) for 100 hours.

  The method of curing the thermosetting furan resin composition is not particularly limited, a method of curing a container containing the thermosetting furan resin composition with hot air, pouring the thermosetting furan resin composition into a mold, For example, a method of heat-curing by sandwiching between hot air or a hot plate can be used.

A cured product such as the furan resin laminate described above using the thermosetting furan resin composition of the present invention has a long pot life and a flexural modulus.
For example, the pot life is preferably longer than 6 hours, longer than 11 hours, longer than 15 hours, and preferably longer than 20 hours. The pot life is a commercially available gel time tester, for example, No. manufactured by Yasuda Seiki Seisakusho Co., Ltd. 153 (torque 3.85 to 4.00 g · cm). For example, it can be measured as the time until 5 g of the thermosetting furan resin composition housed in a test tube having an outer diameter of φ12 mm × an inner diameter of φ8 mm × 90 mmL is gelled at 20 ° C.

  The bending elastic modulus is preferably 1700 MPa or more, more preferably 2000 MPa or more and 2200 MPa or more. The flexural modulus is a value measured by the principle of a three-point bending test (DIN EN ISO178 (JIS K 7171)), and can be measured by a commercially available testing machine. As a test piece to be subjected to the test, for example, a test piece having a length of 100 mm and a width of 15 mm is suitable.

  EXAMPLES Hereinafter, although the thermosetting furan resin composition of this invention and the furan resin laminated body using the same are demonstrated in detail according to an Example, this invention is not limited at all by these Examples.

(Preparation of thermosetting furan resin composition and furan resin laminate)
Example 1
For 100 parts by weight of furan resin,
1 part by weight of a curing agent (65% by weight para-toluenesulfonic acid aqueous solution)
2 parts by weight of ammonium bromide as a curing catalyst 30 parts by weight of aminosilane surface-treated kaolin (manufactured by BASF) as an inorganic filler,
As an inorganic additive, 5 parts by weight of a 40 wt% lithium chloride aqueous solution was added. Thereafter, these were stirred at 1000 rpm for 10 minutes to obtain a thermosetting furan resin composition.

  The thermosetting furan resin composition was impregnated into a nonwoven fabric having a length of 230 mm, a width of 230 mm, and a thickness of 5 mm. Then, this was put into a mold having a length of 240 mm × width of 240 mm × thickness of 5 mm, and the oven temperature was heated at 60 ° C. for 7 hours. Then, it cooled to room temperature in oven, and obtained the furan resin laminated board.

Example 2
A thermosetting furan resin composition was obtained in the same manner as in Example 1 except that 1.0 part by weight of a 65% by weight aqueous solution of paratoluenesulfonic acid was used as the curing agent and 3.2 parts by weight of ammonium bromide was used as the curing catalyst. Using this thermosetting furan resin composition, a furan resin laminate was obtained in the same manner as in Example 1.

Example 3
A thermosetting furan resin composition was obtained in the same manner as in Example 1 except that 0.8 parts by weight of a 65% by weight aqueous solution of paratoluenesulfonic acid was used as a curing agent and 3.2 parts by weight of ammonium bromide was used as a curing catalyst. Using this thermosetting furan resin composition, a furan resin laminate was obtained in the same manner as in Example 1.

Example 4
A thermosetting furan resin composition was obtained in the same manner as in Example 1 except that 0.8 parts by weight of a 65% by weight aqueous solution of paratoluenesulfonic acid was used as the curing agent and 4.0 parts by weight of ammonium bromide was used as the curing catalyst. Using this thermosetting furan resin composition, a furan resin laminate was obtained in the same manner as in Example 1.

Comparative Example 1
A thermosetting furan resin composition was obtained in the same manner as in Example 1 except that 1.0 part by weight of a 65% by weight aqueous solution of paratoluenesulfonic acid as a curing agent and no curing catalyst were added, and this thermosetting furan resin composition was obtained. A furan resin laminate was obtained in the same manner as in Example 1.

Comparative Example 2
A thermosetting furan resin composition was obtained in the same manner as in Example 1 except that 2.0 parts by weight of a 65% by weight aqueous solution of paratoluenesulfonic acid as a curing agent and no curing catalyst were added, and this thermosetting furan resin composition was obtained. The furan resin laminated board was obtained by the method similar to Example 1 using the thing.

Comparative Example 3
A thermosetting furan resin composition was obtained in the same manner as in Example 1 except that no curing agent was added and 3.2 parts by weight of ammonium chloride was used as a curing catalyst, and this thermosetting furan resin composition was used. A furan resin laminate was obtained in the same manner as in Example 1.

Comparative Example 4
A thermosetting furan resin composition was obtained in the same manner as in Example 1 except that 1.0 part by weight of a 65% by weight aqueous solution of paratoluenesulfonic acid was used as a curing agent and 2.0 parts by weight of an aqueous ammonium chloride solution was used as a curing catalyst. Using this thermosetting furan resin composition, a furan resin laminate was obtained in the same manner as in Example 1.

Comparative Example 5
A thermosetting furan resin composition was obtained in the same manner as in Example 1, except that 1.4 parts by weight of a 65% by weight aqueous solution of paratoluenesulfonic acid was used as the curing agent and 2.0 parts by weight of ethylammonium chloride was used as the curing catalyst. Using this thermosetting furan resin composition, a furan resin laminate was obtained in the same manner as in Example 1.

  The thermosetting furan resin compositions and furan resin laminates obtained in Examples and Comparative Examples were evaluated as follows, and the evaluation results are shown in Table 1.

(Pot life time)
Gel Time Tester No. 153 (Yasuda Seiki Seisakusho Co., Ltd., torque 3.85 to 4.00 g · cm), 5 g of thermosetting furan resin composition is added to a test tube having an outer diameter of φ12 mm × an inner diameter of φ8 mm × 90 mmL, and under a condition of 20 ° C. The time until gelation was measured.

(Flexural modulus)
A test piece having a length of 100 mm and a width of 15 mm was cut out from the furan resin laminates obtained in Examples 1 to 4 and Comparative Examples 1 to 5, and a three-point bending test (DIN EN ISO178 (JIS K 7171). ) To measure the flexural modulus.

(NH ₄ Br: ammonium bromide, NH ₄ Cl: ammonium chloride, EAC: ethyl ammonium chloride)

Table 1 shows that in Examples 1 to 4, it was possible to obtain a thermosetting furan resin composition having a sufficient flexural modulus and compatible with a long-term pot life.
In Comparative Example 1, the thermosetting furan resin composition has an insufficient bending elastic modulus although the pot life can be prolonged.
In Comparative Example 2, the thermosetting furan resin composition has a sufficient flexural modulus but shortens the pot life.
In the comparative example 3, it becomes the result of making it harden | cure in a rubber-like state, and it is a thermosetting furan resin composition with insufficient hardening.
In Comparative Example 4, the thermosetting furan resin composition has a sufficient flexural modulus but shortens the pot life.
In Comparative Example 5, the pot life can be prolonged, but the thermosetting furan resin composition has an insufficient bending elastic modulus.

  The present invention is applicable as a matrix resin for composite materials such as steel pipe lining, medge cement, and FRP.

Claims (5)

A thermosetting furan resin composition comprising a furan resin, a curing agent and a curing catalyst,
The thermosetting furan resin composition, wherein the curing catalyst is a brominated amine salt or an ammonium bromide salt.   The thermosetting furan resin composition according to claim 1, wherein the curing catalyst is at least one selected from the group consisting of ammonium bromide, ethyl bromide, diethylamine bromide, methylamine bromide and dimethylamine bromide. object.   The thermosetting furan resin composition according to claim 1 or 2, wherein the curing catalyst is contained in an amount of 0.8 to 4.0 parts by weight with respect to 100 parts by weight of the furan resin.   The thermosetting furan resin composition according to any one of claims 1 to 3, wherein 0.5 to 1.5 parts by weight of the curing agent is contained with respect to 100 parts by weight of the furan resin. The furan resin laminated body formed by making the laminated body containing a reinforced fiber impregnate and harden the thermosetting furan resin composition as described in any one of Claims 1-4.