JP7767758B2 - Composite, method for producing bisphenols, and curing agent - Google Patents

Description

The present invention relates to a composite containing a heteropolyacid compound. The present invention also relates to a method for producing bisphenols using the composite as a catalyst, or a curing agent using the composite.

Heteropolyacid compounds have strong acid strength and oxidizing power and are mainly used as solid acid catalysts.
Patent Document 1 discloses a method for producing bisphenols using a heteropolyacid or a salt thereof as a catalyst. However, heteropolyacid compounds are usually hydrates and contain water of crystallization. If the amount of water of crystallization is large, problems such as a decrease in yield can occur when the heteropolyacid compound is used as a catalyst.

Patent Document 2 also proposes a method for easily producing a composite of a heteropolyacid compound and a polymer as a use for heteropolyacid compounds other than as a catalyst, and a composite obtained by this method that has high transparency and a desired refractive index. The technology described in Patent Document 2 relates to applications that utilize the solubility and high refractive index of heteropolyacid compounds. However, when heteropolyacid compounds are blended with resins, etc., the water of crystallization can sometimes cause a decrease in film properties. Furthermore, while the water of crystallization can be reduced by drying, the hydration structure is reversible, so there is the problem that the water of crystallization returns to its original state over time.

Japanese Patent Application Publication No. 2-45439 International Publication No. 2013/191130

The present invention was developed in consideration of the problems of the above-mentioned conventional technology, and aims to provide a technology that uses heteropolyacid compounds that have little water of crystallization that affects catalytic activity and membrane properties, and that do not undergo reversible changes in the amount of water of crystallization.

As a result of extensive research into heteropolyacid compounds, the inventors discovered that by combining a heteropolyacid compound with a compound having a specific structure, it is possible to prevent the heteropolyacid from forming a hydrated structure and obtain a heteropolyacid compound composite that does not undergo reversible changes in water of crystallization.

To solve this problem, the first aspect of the present invention is a composite that contains a heteropolyacid compound (A) and a compound (B) having at least one amide group and at least one hydroxyl group, wherein the heteropolyacid compound (A) is one or more compounds selected from the group consisting of tungsten-containing heteropolyacids and salts thereof, and molybdenum-containing heteropolyacids and salts thereof, and that exhibits a weight change of less than 1% between 20°C and 200°C.

According to the embodiment of the present invention, it is possible to obtain a heteropolyacid compound-containing composite having a small amount of crystallization water and having no or only a small reversible change in the amount of crystallization water.
The composite according to this embodiment of the present invention can be used as a catalyst in the synthesis of organic compounds, or can be suitably incorporated into coating films as a functional substance.

Hereinafter, an embodiment based on the present invention will be described.
(First embodiment: composite)
The composite of this embodiment is a composite containing a heteropolyacid compound (A) and a compound (B).

The heteropolyacid compound (A) is a compound selected from the group consisting of tungsten-containing heteropolyacids and salts thereof, and molybdenum-containing heteropolyacids and salts thereof.
The compound (B) is a compound having at least one amide group and at least one hydroxyl group.

The compound (B) preferably has a structure represented by the chemical formula (1), for example.

Here, R1 and R2 in formula (1) may be selected appropriately.
Examples of R1 and R2 each independently include a hydrogen atom, a hydroxy group, a hydroxyalkyl group, a hydroxyalkenyl group, a hydroxyaralkyl group, a hydroxyaryl group, a carboxy group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group, and an aryl group.

Furthermore, the composite of this embodiment exhibits a weight change of less than 1% between 20°C and 200°C.

In this embodiment, by complexing heteropolyacid compound (A) and compound (B), it is believed that the amide groups and hydroxyl groups of compound (B) act on the binding sites of the crystal water of the heteropolyacid compound, resulting in irreversible bonding. As a result, the composite of this embodiment can suppress weight change to less than 1% at temperatures between 20°C and 200°C. In other words, the composite of this embodiment suppresses hydration of crystal water and temperature-dependent changes in crystal water.

Here, the weight change of the composite can be determined by thermogravimetric analysis-differential thermal analysis (TG-DTA) in the presence of oxygen, by heating from 20°C to 200°C.

(Second embodiment: method for producing bisphenols)
The method for producing bisphenols according to this embodiment is characterized in that the composite according to this embodiment is used as a solid acid catalyst.

That is, in the method for producing bisphenols of the present embodiment, the composite of the present embodiment is used as a catalyst when a carbonyl compound is reacted with a phenol to produce bisphenols.
This makes it possible to produce bisphenols in good yield (see the examples below).

(Third embodiment: curing agent)
The composite of the present embodiment may be used as a curing agent. When used as a curing agent, a composite using a compound (B) having a reactive group is used.

Each compound will be explained in more detail below.
(Heteropolyacid Compound (A))
The heteropolyacid compound used in this embodiment is selected from the group consisting of tungsten-containing heteropolyacids and salts thereof, and molybdenum-containing heteropolyacids and salts thereof.

Non-limiting examples of tungsten-containing heteropolyacids and molybdenum-containing heteropolyacids include silicotungstic acid (such as H ₄ [SiW ₁₂ O ₄₀ ]), phosphotungstic acid (such as H ₃ [PW ₁₂ O ₄₀ ]), silicomolybdic acid (such as H ₄ [SiMo ₁₂ O ₄₀ ]), phosphomolybdic acid (such as H ₃ [PMo ₁₂ O ₄₀ ]), phosphotungstomolybdic acid (such as H ₃ [PW ₁₂ -xMoxO ₄₀ ]), and phosphovanadomolybdic acid (such as H ₃ [PV ₁₂ -xMoxO ₄₀ ]).
Specific examples of the salts of these heteropolyacids include alkali metal salts such as sodium and potassium, and ammonium salts.

Here, the aforementioned heteropolyacids and salts thereof may be hydrates, or may be anhydrides or salts with a low content of water of crystallization obtained by heat-treating the hydrates. Furthermore, the heteropolyacid compound (A) may be one of the aforementioned heteropolyacids or salts thereof, or a combination of two or more heteropolyacids or salts thereof.

(Compound (B))
The compound (B) used in this embodiment has at least one amide group and at least one hydroxyl group.

Compound (B) preferably has the structure shown in formula (1). With the structure shown in formula (1), the amide group and the hydroxyl group are at an appropriate distance from each other, so it is believed that the composite will be efficiently complexed.

Examples of compound (B) having such a structure include N-(2-hydroxyethyl)acrylamide, N-(2-hydroxyethyl)acetamide, N-(2-hydroxyethyl)propionamide, N-(2-hydroxyethyl)lactamide, N-(2-hydroxyethyl)hexadecanamide, N,N-bis(2-hydroxyethyl)octanamide, N-(2-hydroxyethyl)acrylamide, N-(hydroxymethyl)acrylamide, and N,N,N',N'-tetrakis(2-hydroxyethyl)hexanediamide.

When the composite of this embodiment is used as a solid acid catalyst, it is preferable that compound (B) does not have a reactive group. Therefore, N-(2-hydroxyethyl)acetamide or N-(2-hydroxyethyl)propionamide can be suitably used as the composite for the solid acid catalyst.

When compound (B) has a reactive group (when at least one of R1 and R2 is a reactive group), the composite of this embodiment can be used as a curing agent. The reactive group can be appropriately selected from, for example, a carbon-carbon double bond, an epoxy group, a silanol group, a peroxide, an azo compound, etc.

A monomer suitable for each reactive group is mixed with the composite of this embodiment to carry out a polymerization reaction. During this polymerization reaction, the composite of this embodiment acts as a curing agent, allowing a resin composition with a crosslinked structure to be obtained.

The ratio of the heteropolyacid compound (A) to the compound (B) constituting the composite can be appropriately selected. It is preferable to composite the compound (B) in approximately the same number of moles as the number of moles of water of hydration of the heteropolyacid compound (A) alone.
The method for producing the composite of this embodiment is not particularly limited, and it can be prepared according to a known production method.

When compound (B) shown in formula (1) is used as compound (B), the composite is produced, for example, as follows. That is, heteropolyacid compound (A) is dissolved in a solvent such as an alcohol or ether, and compound (B) is mixed therewith to produce the composite. Alternatively, when compound (B) is a liquid, heteropolyacid compound (A) and compound (B) are directly mixed to produce the composite.

At this time, the complex precipitated in the mixed solution or the complex directly mixed is washed with a solvent such as water, alcohols, or ethers. The complex is then recovered from the solvent used for washing by centrifugation or filtration, and further dried to obtain a complex of heteropolyacid compound (A) and compound (B). The mixing time is preferably about 30 minutes to 3 days after addition. The drying temperature is preferably 50 to 150°C, and the drying time is preferably about 1 hour to 3 days.

(others)
The present disclosure may also have the following configuration.
(1) A composition comprising a heteropolyacid compound (A) and a compound (B) having at least one amide group and at least one hydroxyl group,
the heteropolyacid compound (A) is one or more compounds selected from the group consisting of tungsten-containing heteropolyacids and salts thereof, and molybdenum-containing heteropolyacids and salts thereof,
A composite that exhibits a weight change of less than 1% between 20°C and 200°C.
(2) A complex in which the compound (B) is a compound having a structure represented by formula (1).

(3) A method for producing bisphenols, comprising reacting a carbonyl compound with a phenol using the composite of the present disclosure as a solid acid catalyst to produce bisphenols.
(4) A curing agent using the composite of the present disclosure, wherein the compound (B) has a reactive group.

The present invention will be described in more detail below with reference to examples and comparative examples.
Example 1
<Example 1-1>
In Example 1-1, an aqueous solution (70 wt %) of tungstosilicic acid 30 hydrate (SiW12, manufactured by Nippon Shinkinzoku Co., Ltd.) was used as the heteropolyacid compound (A).

As the compound (B), N-(2-hydroxyethyl)acrylamide (HEAA, manufactured by Tokyo Chemical Industry Co., Ltd.) was used.
Then, the heteropolyacid compound (A) and the compound (B) were mixed in a weight ratio of 80:20 to prepare a mixed solution containing a complex.

The prepared mixture was stirred for 3 hours and then dried overnight in an environment of 100° C. to obtain a solid composite of Example 1-1.
The weight change of the obtained composite at 20°C to 200°C was 0.54%.

<Examples 1-2 to 1-5, Comparative Examples 1-1 to 1-3>
The composites of Examples 1-2 to 1-5 and Comparative Examples 1-1 to 1-3 were obtained under the same conditions as in Example 1-1, except that the heteropolyacid compound (A) and the compound (B) were changed to the substances shown in Table 1. The weight change of each of the obtained composites at 20 to 200°C is also shown in Table 1.
The phosphotungstic acid used as the heteropolyacid compound (A) was manufactured by Nippon Shinkinzoku Co., Ltd. All of the substances used for the compound (B) shown in Table 1 were manufactured by Tokyo Chemical Industry Co., Ltd.

As can be seen from Table 1, in Examples 1-1 to 1-5, in which a compound having one or more amide groups and one or more hydroxyl groups was used as compound (B), the weight change at 20-200°C was less than 1%, demonstrating that reversible weight change was suppressed.

Example 2
Example 2 is an example of producing bisphenols by reacting a carbonyl compound with a phenol.

In the following examples, acetone was used as the carbonyl compound.

<Example 2-1>
A reactor equipped with a reflux condenser and a stirrer was charged with 1.88 g (20 mmol) of phenol and 0.1 g (0.03 mmol) of the solid composite obtained in Example 1-2, and 0.12 g (2.0 mmol) of acetone was added thereto, followed by reaction at 80°C for 6 hours.
The yield of bisphenol A was 60%.

In this example, the yield of bisphenol A was calculated using the following formula based on the results of gas chromatography.

Bisphenol A yield (%)
= (bisphenol A produced (mol) ÷ amount of acetone charged (mol)) × 100

<Comparative Example 2-1>
A reactor equipped with a reflux condenser and a stirrer was charged with 1.88 g (20 mmol) of phenol and 0.095 g (0.03 mmol) of tungstosilicic acid 30 hydrate, and 0.12 g (2.0 mmol) of acetone was added, followed by reaction at 80° C. for 6 hours.
The yield of bisphenol A was 23%.

As can be seen from a comparison between Example 2-1 and Comparative Example 2-1, when producing bisphenols, the yield of bisphenol A is significantly higher when the composite based on the present invention is used as a catalyst compared to when a heteropolyacid compound (Comparative Example 2-1) is used alone as a catalyst.

Example 3
Example 3 is an example that shows the advantages of using the composite of the present invention as a curing agent.
<Example 3-1>
A composition was prepared by mixing 90 parts by weight of 2-hydroxyethyl methacrylate, 3 parts by weight of azobisisobutyronitrile (AIBN), and 7 parts by weight of the complex obtained in Example 1-1.

The composition was left to stand overnight under a nitrogen atmosphere at an ambient temperature of 60°C, yielding a solid resin composition.

When the resulting resin composition was immersed in water, it did not dissolve and maintained its shape.

<Comparative Example 3-1>
A resin composition was prepared under the same conditions as in Example 3-1, except that the composite obtained in Example 1-1 was not added.
When the obtained resin composition was immersed in water, it dissolved.

<Comparative Example 3-2>
A resin composition was prepared under the same conditions as in Example 3-1, except that silicotungstic acid 30-hydrate was used instead of the composite obtained in Example 1-1.
When the obtained resin composition was immersed in water, it dissolved.

As can be seen from a comparison between Example 3-1 and Comparative Examples 3-1 and 3-2, when the composite based on the present invention in which the compound (B) has a reactive group was mixed, the hardness of the resin composition was found to be significantly increased. In other words, it was found that the composite based on the present invention can be used as a curing agent.

Claims (5)

The composition contains only two types of compounds: a heteropolyacid compound (A) and a compound (B) having at least one amide group and at least one hydroxyl group;
the heteropolyacid compound (A) is one or more compounds selected from the group consisting of tungsten-containing heteropolyacids and salts thereof, and molybdenum-containing heteropolyacids and salts thereof,
the compound (B) is any one of N-(2-hydroxyethyl)acrylamide, N-(2-hydroxyethyl)acetamide, N-(2-hydroxyethyl)propionamide, N-(hydroxymethyl)acrylamide, N-(hydroxymethyl)acetamide, and N-(hydroxymethyl)propionamide;
A composite characterized by a weight change of less than 1% at temperatures between 20°C and 200°C. A method for producing bisphenols by reacting a carbonyl compound with a phenol using the composite according to claim 1 as a solid acid catalyst.
A method for producing bisphenols. A curing agent using the composite according to claim 1,
A curing agent characterized in that the compound (B) is either N-(2-hydroxyethyl)acrylamide or N-(hydroxymethyl)acrylamide . The composition contains a heteropolyacid compound (A) and a compound (B) having at least one amide group and at least one hydroxyl group,
the heteropolyacid compound (A) is one or more compounds selected from the group consisting of tungsten-containing heteropolyacids and salts thereof, and molybdenum-containing heteropolyacids and salts thereof,
the compound (B) is any one of N-(2-hydroxyethyl)acrylamide, N-(2-hydroxyethyl)acetamide, N-(2-hydroxyethyl)propionamide, N-(hydroxymethyl)acrylamide, N-(hydroxymethyl)acetamide, and N-(hydroxymethyl)propionamide;
a method for producing bisphenols by reacting a carbonyl compound with a phenol using, as a solid acid catalyst, a composite characterized by a weight change of less than 1% at 20°C to 200°C;
A method for producing bisphenols. The composition contains a heteropolyacid compound (A) and a compound (B) having at least one amide group and at least one hydroxyl group,
the heteropolyacid compound (A) is one or more compounds selected from the group consisting of tungsten-containing heteropolyacids and salts thereof, and molybdenum-containing heteropolyacids and salts thereof,
the compound (B) is any one of N-(2-hydroxyethyl)acrylamide, N-(2-hydroxyethyl)acetamide, N-(2-hydroxyethyl)propionamide, N-(hydroxymethyl)acrylamide, N-(hydroxymethyl)acetamide, and N-(hydroxymethyl)propionamide;
A curing agent using a composite characterized in that the weight change at 20°C to 200°C is less than 1%,
A curing agent characterized in that the compound (B) is either N-(2-hydroxyethyl)acrylamide or N-(hydroxymethyl)acrylamide .