WO2025203281A1 - Polymer resin composition and method for producing same - Google Patents

Abstract

The present invention provides a polymer resin composition excellent in strength and glass transition temperature and environmental suitability, and a method for producing the same.　This polymer resin composition is produced by subjecting a mixture obtained by mixing an ether group-containing epoxy resin and a hydroxy group-containing phenolic curing agent to a heating and curing process, and the hydroxy group-containing phenolic curing agent has a hydroxy group content of 9 mmol/g or less.

Description

Polymer resin composition and method for producing same

The present invention relates to a polymer resin composition and a method for producing the same.

Efforts to mitigate or reduce the impact of climate change have been ongoing for some time, and research and development into reducing carbon dioxide emissions has been conducted to achieve this. In particular, one technology that can contribute to reducing carbon dioxide emissions is the technology of producing plastic materials used in the manufacture of electronic components, etc., using biomass raw materials.
For example, Patent Document 1 discloses a technique for producing a polymer resin composition by blending epoxidized linseed oil, which is a hydrophobic epoxy resin containing an aryl ring skeleton or a long-chain alkyl group as a main component, a plant extract containing tannin as a phenolic hardener, and glycerin polyglycidyl ether, which is an ether group-containing epoxy resin.

JP 2012-007076 A

In reducing carbon dioxide emissions, the challenge is to obtain polymer resin compositions with desired physical properties, such as strength and glass transition temperature, by using plant-derived raw materials.

In order to solve the above problems, the present application aims to produce a polymer resin composition and molded articles thereof that have excellent strength, glass transition temperature, and environmental compatibility. This will ultimately contribute to mitigating or reducing the impact of climate change.

In order to achieve the above objective, the polymer resin composition of the present invention is produced by mixing an ether group-containing epoxy resin with a hydroxyl group-containing phenolic curing agent, and then subjecting the mixture to a heat curing treatment, and the hydroxyl group amount of the hydroxyl group-containing phenolic curing agent is 9 mmol/g or less.

According to the present invention, a polymer resin composition with specified physical properties can be obtained.

FIG. 1 is a process diagram showing a method for producing a polymer resin composition.

[1. Polymer resin composition]
In recent years, research and development aimed at reducing carbon dioxide emissions has led to the study of biomass-based epoxy resins.
However, polymer resin compositions using biomass-based epoxy resins often lack sufficient performance, such as strength and glass transition temperature, compared to petroleum-derived epoxy resins, and are unable to meet the necessary standards, so they have rarely been used as insulating materials.

An example of an electronic material that uses a polymer resin composition is the FR-4 electronic circuit board, which is widely used in automobiles. FR-4 grade electronic circuit boards, as defined by ANSI/NEMA standards, require the use of a polymer resin composition that meets the following requirements: a glass transition temperature of 120°C or higher, a bending stress (flexural strength) of 50 MPa or higher, and a flexural modulus of elasticity of 1600 MPa or higher. A similar glass transition temperature is also required for GE4F flame-resistant glass cloth-based epoxy resin copper-clad laminates, as defined by JIS C6484. Other uses for polymer resin compositions include IC encapsulation resins, which generally require a bending strength of 60 MPa to 70 MPa or higher. The matrix resin used in general structural FRP requires a bending strength of 100 MPa or higher.

The inventors have discovered a polymer resin composition that can be used in a wider range of applications than conventional polymer resin compositions, by mixing an epoxy resin with an epoxy equivalent of 192 g/eq or less with a phenolic curing agent with a hydroxyl group content of 9 mmol/g or less and then subjecting the mixture to a heat curing treatment under specified conditions.

Furthermore, by mixing epoxy resin with a phenolic curing agent, and then further adding epoxidized vegetable oil, which has flexibility, and then subjecting the mixture to a heat-curing treatment under specified conditions, the researchers were able to improve bending stress, resulting in a polymer resin composition that can be used in a wider range of applications and is applicable to a wider variety of electronic components than conventional polymer resin compositions made from bio-based materials.

The epoxy resin, phenolic curing agent, and epoxidized vegetable oil can all be derived from bio-based raw materials. This means that it is possible to produce a polymer resin composition that meets established standards and is 100% derived from bio-based raw materials.

The polymer resin composition obtained by this method has a high glass transition temperature and strength, making it an ideal material for electronic components and electronic substrates.

The polymer resin composition produced by the method discovered by the inventors is a thermosetting resin composition that has the advantage of having a high glass transition temperature and strength despite using a bio-derived epoxy resin. Here, the glass transition temperature is measured using the method specified in JIS K7121. In this embodiment, strength refers to the bending stress and bending modulus. The bending stress and bending modulus are measured using the method specified in JIS K7171.

[2. Production of polymer resin composition]
FIG. 1 is a process diagram showing a method for producing a polymer resin composition.
In the method for producing a polymeric resin composition according to the present disclosure, a first mixing step S1 is first carried out in which a first main agent and a curing agent are charged into a mixer and then mixed in the mixer. In the first mixing step S1, the first main agent and the curing agent are mixed in the mixer to obtain a first mixture.

The first main component uses an ether group-containing epoxy resin with an epoxy equivalent of 192 g/eq or less. This increases the crosslink density of the resulting polymer resin composition, resulting in a polymer resin composition with a flexural modulus of 1600 MPa or more.

Examples of ether group-containing epoxy resins with an epoxy equivalent of 192 g/eq or less include sorbitol glycidyl ether (e.g., Denacol EX-614B (epoxy equivalent: 173 g/eq) manufactured by Nagase ChemteX Corporation) and limonene dioxide (e.g., Celloxide 3000 (epoxy equivalent: 166 g/eq) manufactured by Daicel Corporation).

The amount of hydroxyl-containing phenolic curing agent used as a curing agent is calculated so that it is equivalent to the epoxy groups in the base resin. For example, it is preferable to specify that the amount of hydroxyl groups is 9 mmol/g or less. By keeping the amount of hydroxyl groups at 9 mmol/g or less, even if a large amount of curing agent is added, raw materials will not remain undissolved or the mixture will not harden properly during the manufacturing process of the polymer resin composition, and a polymer resin composition with a glass transition temperature of 120°C or higher can be obtained.

Examples of hydroxyl group-containing phenolic hardeners include polyethylene glycol lignin (e.g., Lignotop manufactured by Lignomateria Co., Ltd.), lignin oligomer (e.g., Bloom Lignin Oligomer manufactured by Bloom Biorenewables SA), and daidzein (e.g., Daidzein manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

Next, a second main component made of epoxidized vegetable oil is added to the obtained first mixture, and the mixture is mixed and stirred in a second mixing step S2. In the second mixing step S2, the first mixture and the second main component are mixed to obtain a second mixture.

The second main agent is preferably an epoxidized vegetable oil, which has flexibility. It is also preferable to manufacture the polymer resin composition with an added amount of the second main agent of 15% or less. This allows the resulting polymer resin composition to have improved bending stress compared to a polymer resin composition manufactured without adding epoxidized vegetable oil. In other words, a polymer resin composition is obtained that can be used in a wide range of applications and is applicable to various types of electronic components.

Furthermore, the polymer resin composition can be produced without adding the second main agent. In that case, the second mixing step S2 may be omitted.

Examples of flexible epoxidized vegetable oils include epoxidized soybean oil (e.g., Adeka Cizer O-130P manufactured by ADEKA Corporation and Sanso Cizer E-2000H manufactured by New Japan Chemical Co., Ltd.), epoxidized castor oil (e.g., EPOX MK R151 manufactured by Printec Co., Ltd.), and epoxidized linseed oil (e.g., Adeka Cizer O-180A manufactured by ADEKA Corporation and Sanso Cizer E-9000H manufactured by New Japan Chemical Co., Ltd.).

Next, a heating step S3 is performed in which the obtained second mixture is heated at a temperature lower than the heat curing temperature to reduce the viscosity of the mixture. For example, heating step S3 involves heating at 100°C for 10 minutes.

Next, the casting process S4 is performed, in which the second mixture heated in the heating process S3 is injected into a mold.

After the casting process S4, the heat-curing process S5 is performed, in which the second mixture injected into the mold is heated to a heat-curing temperature. In this embodiment, the heat-curing process S5 involves heating at 160°C for two hours to harden the second mixture.

Then, the second mixture that has been heat-cured in the heat-curing step S5 is released from the mold in the demolding step S6, yielding a polymer resin composition.

The polymer resin composition obtained by the manufacturing method disclosed herein is measured for bending stress and bending modulus according to the method described in JIS K7171. Furthermore, the polymer resin composition obtained by the manufacturing method disclosed herein is measured for glass transition temperature according to the method described in JIS K7121.

3. Examples
Examples of polymer resin compositions produced by the production method of the present disclosure, with the types and amounts of the first main component, curing agent, and second main component being varied, are shown as Examples 1 to 11 and Comparative Examples 1 to 3. The present disclosure is not limited in any way by these Examples.

In this embodiment, the first main agent was one selected from sorbitol polyglycidyl ether (Denacol EX-614B, manufactured by Nagase ChemteX Corporation) and bisphenol A epoxy resin. The curing agent was one selected from polyethylene glycol lignin (Lignotop SD4, manufactured by Lignomateria Co., Ltd.) and tannic acid (AL tannic acid, manufactured by Fuji Chemical Industry Co., Ltd.). The second main agent was one selected from epoxidized soybean oil (Adeka Cizer O-130P, manufactured by ADEKA Corporation) and epoxidized linseed oil (Adeka Cizer O-180A, manufactured by ADEKA Corporation).

Glass transition temperature was measured using a Thermo Plus EVO2 manufactured by Rigaku Holdings Corporation under conditions in accordance with JIS K7121. Flexural stress and flexural modulus were measured using an Autograph manufactured by Shimadzu Corporation under conditions in accordance with JIS K7171.

Examples 1, 2, Comparative Examples 1, and 2 are examples in which polymer resin compositions were produced by varying the types and amounts of the first main agent, curing agent, and second main agent. Table 1 shows the bending stress and glass transition temperature for these examples.

In Examples 1 and 2, sorbitol glycidyl ether was used as the first main agent, and polyethylene glycol lignin was used as the hardener. Epoxidized soybean oil was used as the second main agent. In Comparative Examples 1 and 2, the first and second main agents were the same as in Examples 1 and 2, and tannic acid was used as the hardener.

As shown in Example 2 in Table 1, by adding 40% or more polyethylene glycol lignin as a curing agent, a polymer resin composition with a glass transition temperature of 120°C or higher was obtained.

As shown in Comparative Examples 1 and 2, when tannic acid was used as the curing agent, the glass transition temperature of the polymer resin composition produced with an added amount of tannic acid of less than 40% did not exceed 120°C. Furthermore, when a polymer resin composition was produced with an added amount of tannic acid of 40% or more (Comparative Example 2), poor curing (or insoluble residue) occurred, making it impossible to produce a cured product.

As shown in Examples 1, 2, and Comparative Examples 1 and 2, it was found that a higher glass transition temperature can be obtained by increasing the amount of curing agent added. In other words, by increasing the amount of curing agent added, it is possible to produce a polymer resin composition that can be used in a wide range of applications and is applicable to various types of electronic components.

In Examples 3 and 4, polymer resin compositions were produced by varying the amounts of sorbitol glycidyl ether (the first main agent) and polyethylene glycol lignin (the curing agent). Table 2 shows the results of measuring the hydroxyl group content of each composition. The hydroxyl group content of the curing agent is measured by neutralization titration, NMR spectroscopy, or other known methods. The amounts added shown in Table 2 are the amounts added when the amount of hydroxyl groups in the curing agent is equivalent to the amount of epoxy groups in the main agent, and are the upper limit of the amount added for each curing agent.

As shown in Examples 3 and 4 in Table 2, the lower the hydroxyl group content, the higher the amount of curing agent that can be added. As a result, a polymer resin composition with a high glass transition temperature can be obtained by adding a larger amount of curing agent.

Examples 5 to 7 and Comparative Example 3 compare the flexural modulus of polymer resin compositions when the first main component is changed. Epoxidized cardanol (FE-5130, manufactured by Tohoku Kako Co., Ltd.) was used as the cardanol in Example 7. The first main components and curing agents in Examples 5 and 6 are as described above. Comparative Example 3 used a resin material used in commercially available FR-4 boards. Specifically, bisphenol A-type epoxy resin (JER828, manufactured by Mitsubishi Chemical Corporation) was used as the main component, and dicyandiamide (DICY, manufactured by Nippon Carbide Co., Ltd.) was used as the curing agent.

As shown in Table 3, a lower epoxy equivalent weight results in a higher flexural modulus. Specifically, when the epoxy equivalent weight is 192 g/eq or less, a polymer resin composition with a high flexural modulus of 1600 MPa or more can be obtained.

Examples 8 to 11 are examples of polymer resin compositions produced using bisphenol A epoxy resin (JER828, manufactured by Mitsubishi Chemical Corporation) as the first main agent, methyl-3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride (MHAC-P, manufactured by Resonac Corporation) as the curing agent, and epoxidized linseed oil (ADEKA Cizer O-180A, manufactured by ADEKA Corporation) as the second main agent. Examples 8 to 11 compare the bending stress of polymer resin compositions when the amount of second main agent added is changed.

As shown in Table 4, it was found that the smaller the amount of second main agent added, the higher the bending stress of the polymer resin composition. In other words, the more the amount of second main agent added, the lower the bending stress of the polymer resin composition tends to be. When the amount of second main agent is less than 15% of the first main agent (8% of the entire material), there is a significant increase in the bending stress of the polymer resin composition, and when more than 15% is added, there is a significant tendency for the bending stress to decrease.

4. Other Embodiments
The above-described embodiment merely shows one aspect of the present invention, and any modifications and applications are possible within the scope of the present invention.

In the above-described embodiment, the first main agent and the curing agent are mixed to produce the first mixture, and then the first mixture is mixed with the second main agent. However, the addition of the second mixture does not have to be after the first main agent and the curing agent are mixed. In other words, the first main agent, the curing agent, and the second main agent may be mixed simultaneously, rather than being limited to the stepwise mixing method described in the above embodiment.

The mixers and heaters used in the above-described embodiments are merely examples, and the machines and tools used in the method for producing a polymer resin composition are not limited to those in the above-described embodiments.
Similarly, the size and shape of the mold used in the casting step are not particularly limited.

In the above-described embodiment, the mixture is cured by a heating process in which heating is performed at 100°C for 10 minutes and then at 160°C for 2 hours. However, the temperature and time of the heating process and the heat-curing process are not limited to the conditions in the embodiment. In other words, they can be changed as appropriate depending on the manufacturing method, etc.

5. Configurations supported by the above embodiment
The above embodiment supports the following configurations.

(Configuration 1) A polymeric resin composition produced by mixing an ether group-containing epoxy resin and a hydroxyl group-containing phenolic curing agent, followed by heat curing the resulting mixture, wherein the hydroxyl group amount of the hydroxyl group-containing phenolic curing agent is 9 mmol/g or less.
According to this configuration, by setting the hydroxyl group amount of the hydroxyl group-containing phenolic curing agent to 9 mmol/g or less, the amount of phenolic curing agent added during production of the polymer resin composition can be increased, and a polymer resin composition having predetermined physical properties can be obtained.

(Configuration 2) The polymeric resin composition according to Configuration 1, wherein the ether group-containing epoxy resin has an epoxy equivalent of 192 g/eq or less.
According to this configuration, by setting the epoxy equivalent of the ether group-containing epoxy resin to 192 g/eq or less, the flexural modulus of the polymer resin composition can be improved, and a polymer resin composition having predetermined physical properties can be obtained.

(Configuration 3) The polymeric resin composition according to Configuration 1 or 2, having a glass transition temperature of 120°C or higher.
According to this configuration, since the glass transition temperature is 120° C. or higher, it is possible to obtain a polymer resin composition having a glass transition temperature that is applicable to FR-4 substrates.

(Configuration 4) The polymeric resin composition according to any one of Configurations 1 to 3, which is produced by adding 40% or more of the hydroxyl group-containing phenolic curing agent.
According to this configuration, by adding 40% or more of a hydroxyl group-containing phenolic curing agent, the glass transition temperature of the polymer resin composition can be increased, and a polymer resin composition having predetermined physical properties can be obtained.

(Configuration 5) The polymeric resin composition according to any one of Configurations 1 to 4, which is produced by mixing the ether group-containing epoxy resin, the hydroxyl group-containing phenolic curing agent, and a flexible epoxidized vegetable oil.
According to this configuration, by adding a flexible epoxidized vegetable oil, the bending stress of the polymer resin composition can be improved, and a polymer resin composition having predetermined physical properties can be obtained.

(Configuration 6) A method for producing a polymeric resin composition, comprising: a mixing step of mixing an ether group-containing epoxy resin with a hydroxyl group-containing phenolic curing agent to produce a mixture; and a heat-curing step of heating the mixture to cure it.
According to this method, a polymer resin composition having predetermined physical properties can be obtained.

(Configuration 7) The method for producing a polymeric resin composition according to claim 6, further comprising a second mixing step of producing a second mixture by stirring and mixing a flexible epoxidized vegetable oil into the mixture after the mixing step, and the heat curing step is a step of heating and curing the second mixture.
According to this method, a polymer resin composition having predetermined physical properties can be obtained.

Claims (7)

The epoxy resin is produced by mixing an ether group-containing epoxy resin with a hydroxyl group-containing phenolic curing agent, and then subjecting the mixture to a heat curing treatment.
the hydroxyl group amount of the hydroxyl group-containing phenolic curing agent is 9 mmol/g or less;
Polymer resin composition. The epoxy equivalent of the ether group-containing epoxy resin is 192 g/eq or less.
The polymeric resin composition of claim 1. The glass transition temperature is 120°C or higher.
The polymeric resin composition of claim 1. The hydroxyl group-containing phenolic curing agent is added in an amount of 40% or more.
The polymeric resin composition of claim 1. The epoxy resin composition is produced by mixing the ether group-containing epoxy resin, the hydroxyl group-containing phenolic curing agent, and a flexible epoxidized vegetable oil.
The polymeric resin composition of claim 1. a mixing step of mixing an ether group-containing epoxy resin and a hydroxyl group-containing phenolic curing agent to produce a mixture;
A heat curing step of heating the mixture to cure it.
A method for producing a polymeric resin composition. a second mixing step, after the mixing step, of mixing a flexible epoxidized vegetable oil into the mixture by stirring to produce a second mixture;
The heat curing step is a step of heating the second mixture to cure it.
A method for producing the polymer resin composition according to claim 6.