Application of environment-friendly peroxide cyclohexanone curing agent composition in high-iron putty

Abstract

The application discloses application of an environment-friendly peroxide cyclohexanone curing agent composition in high-iron putty and belongs to the technical field of paints. Esterification materials are obtained through esterification reaction among castor oil acid, terephthalic acid and isooctanol; carbon-carbon double bonds on the molecular chain of the esterification materials are subjected to epoxidation modification to obtain epoxidized esterification materials; and dehydrogenated rosin acid and the epoxidized esterification materials are subjected to ring-opening reaction to synthesize a new desensitizing agent to replace a toxic phthalate desensitizing agent, thereby avoiding use of phthalate compounds, and ensuring that products meet the environmental protection regulations of the European Union. When the curing agent composition is used in cooperation with polyester resin, not only good desensitizing effect can be achieved, but also the putty after curing has excellent physical properties and chemical stability, and thus a powerful guarantee is provided for production and application of high-iron putty.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically relating to the application of an environmentally friendly cyclohexanone peroxide curing agent composition in high-iron putty. Background Technology

[0002] Putty, as a filling material, adheres well to the surface of objects, filling in surface defects, improving aesthetics, and providing a smooth substrate for subsequent construction. Polyester putty, in particular, is widely used in railway locomotives due to its fast curing speed, strong adhesion, good sanding properties, and suitability for large-area application, making it especially suitable for filling or repairing high-speed rail surfaces.

[0003] Patent application CN202410656465.6 discloses a formulation for polyester putty, mainly composed of polyester resin, curing agent, and filler. In the curing reaction system, a desensitizing agent is typically added to the curing agent to weaken the secondary bonds between resin molecules, reduce the viscosity and reactivity of the system, thereby slowing down the reaction rate between the curing agent and the resin, achieving a "desensitization" effect (reducing curing sensitivity). For example, patent application CN202310513600.7 discloses a cyclohexanone peroxide curing agent composition formulation. By adding phthalate desensitizing agents, it exhibits good compatibility and the ability to reduce system viscosity, significantly reducing the intermolecular forces of the polyester resin, making it easier for the curing agent to penetrate into the resin. Without phthalates, the resin molecules are tightly packed and have high viscosity, making it difficult for the curing agent to penetrate. It can only accumulate on the surface or in local gaps, forming a high-concentration area. A large number of curing agent molecules collide rapidly with the active sites of the resin, and the reaction starts quickly. After adding phthalates, the curing agent can easily penetrate and be evenly dispersed inside the resin. The concentration of the curing agent per unit volume is diluted, and the probability of collision with the active sites of the resin is reduced. It cannot quickly reach the concentration threshold required for the reaction to start, thus delaying the reaction start time and avoiding material cracking or performance degradation caused by too rapid a reaction.

[0004] However, phthalate desensitizers do not meet EU product standards and are restricted from use by relevant EU regulations. This means that in the production of high-speed rail putty for the EU market, if curing agents containing phthalate desensitizers are used, the products will face the problem of not being able to enter the market. Therefore, developing environmentally friendly desensitizers for use in curing agents to promote the wider application of high-speed rail putty is particularly important. Summary of the Invention

[0005] The purpose of this invention is to provide an environmentally friendly cyclohexanone peroxide curing agent composition for use in high-speed rail putty, addressing the problem that existing high-speed rail putty formulations contain toxic phthalate desensitizing agents in the curing agent, resulting in products that fail to meet EU environmental requirements. The environmentally friendly cyclohexanone peroxide curing agent composition provided by this invention uses environmentally friendly materials to prepare the desensitizing agent, avoiding the use of phthalate compounds, thereby ensuring that the product complies with EU environmental regulations. When used in combination with polyester resin, this curing agent composition not only provides excellent desensitization effects but also ensures that the cured putty possesses excellent physical properties and chemical stability, providing a strong guarantee for the production and application of high-speed rail putty.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] The application of an environmentally friendly cyclohexanone peroxide curing agent composition in high-speed iron putty, wherein the preparation method of the environmentally friendly cyclohexanone peroxide curing agent composition includes the following steps:

[0008] A1. Using ricinoleic acid, terephthalic acid, and isooctyl alcohol as reactants, an esterification reaction is carried out under the catalysis of a catalyst to obtain esterified materials;

[0009] A2. The esterified material is subjected to epoxidation treatment to obtain an epoxidized esterified material;

[0010] A3. Using dehydrorosin acid and epoxidized esterified materials as reactants, a ring-opening reaction is carried out to obtain a desensitizing agent;

[0011] A4. Mix hydrogen peroxide and inorganic acid to obtain material A;

[0012] A5. Mix cyclohexanone and the desensitizing agent to obtain material B;

[0013] A6. Add material B to material A, stir at 20°C for 1-2 hours, let stand to separate into layers, take the upper oil phase for acid neutralization, add stabilizer and accelerator, stir evenly, and the environmentally friendly cyclohexanone peroxide curing agent composition is obtained.

[0014] In a preferred embodiment of the present invention, in step A1, the catalyst is p-toluenesulfonic acid.

[0015] As a preferred embodiment of the present invention, in step A4, the inorganic acid is selected from any one of sulfuric acid, hydrochloric acid, and nitric acid.

[0016] As a preferred embodiment of the present invention, in step A6, the stabilizer includes at least one of ethylene glycol, glycerol, diacetone alcohol, cyclohexanediol, vinylpyrrolidone, vitamin B2, anthraquinone, and benzyl alcohol.

[0017] As a preferred embodiment of the present invention, in step A6, the accelerator includes at least one of 2,4-pentanedione, triphenylethylphosphine bromide, triphenylbutylphosphine bromide, benzyltriphenylphosphine bromide, benzyltrimethylammonium bromide, benzyltriethylammonium chloride, 2-methylimidazolium, 2-phenylimidazoline, and dimethylaniline.

[0018] As a preferred embodiment of the present invention, the accelerator further includes at least one of cobalt salt and zinc salt.

[0019] As a preferred embodiment of the present invention, the cobalt salt includes at least one of cobalt isooctanoate and cobalt naphthenate.

[0020] As a preferred embodiment of the present invention, the zinc salt includes at least one of zinc neodecanoate and zinc naphthenate.

[0021] The beneficial effects of this invention are:

[0022] (1) The application of the environmentally friendly cyclohexanone peroxide curing agent composition disclosed in this invention in high-speed iron putty is achieved by using the esterification reaction between ricinoleic acid, terephthalic acid, and isooctanol to obtain esterified materials; the carbon-carbon double bonds on the molecular chain of the esterified materials are epoxidized to obtain epoxidized esterified materials; then, dehydrorosin acid and epoxidized esterified materials are used to carry out a ring-opening reaction to synthesize a new desensitizer to replace the toxic phthalate ester desensitizer. The new desensitizer contains a large number of ester groups, which are similar to the ester group structure of polyester resin, have stronger compatibility, and can be uniformly dispersed in the system. The ester groups can weaken the hydrogen bonds and van der Waals forces between resin molecules, reduce the viscosity of the system, dilute the concentration of the curing agent, reduce the probability of collision between the curing agent and the active sites of the resin, and delay the curing start-up time. The long-chain structure derived from ricinoleic acid and the rigid framework of dehydrorosin acid combine flexibility and rigidity. After entanglement with resin molecular chains, they can simultaneously improve the putty's flexibility, impact resistance, and adhesion, ensuring long-term stability within the system and preventing performance degradation in the later stages. The internal plasticizing effect of the ester groups reduces the volume shrinkage rate during resin curing. Combined with the molecular chain entanglement effect, this further reduces microcracks on the putty surface, improving smoothness and aesthetics.

[0023] (2) The application of the environmentally friendly cyclohexanone peroxide curing agent composition disclosed in this invention in high-speed iron putty involves combining the stabilizer diacetone alcohol and the accelerator components composed of 2,4-pentanedione, 2-methylimidazole, cobalt naphthenate, and zinc naphthenate in the curing agent composition formulation. These components can form hydrogen bond interactions with cyclohexanone peroxide, weakening its decomposition activity and preventing the curing agent from decomposing too quickly, resulting in an excessively short gel time. Simultaneously, it exhibits good compatibility with resins and desensitizing agents, ensuring uniform dispersion of the system and guaranteeing a smooth progress of the curing reaction without localized excessively rapid gelation. 2,4-pentanedione can form chelates with metal ions (cobalt and zinc), providing active sites for the curing reaction; 2-methylimidazole can moderately accelerate the decomposition rate of cyclohexanone peroxide, compensating for the slowing effect of diacetone alcohol; cobalt naphthenate and zinc naphthenate, as metal soap accelerators, regulate the free radical generation rate through electron transfer by metal ions. These three components, along with diacetone alcohol, form a rate-controlling-accelerating balance, ultimately achieving a suitable gel time. The hydroxyl groups of diacetone alcohol can form weak hydrogen bonds with the ester groups of resin and desensitizing agents, which neither affects the curing crosslinking nor hinders the lubrication between molecular chains, thus reducing the brittleness caused by excessive crosslinking density. 2-Methylimidazole can form a flexible interface with the resin molecular chains, alleviating the internal stress generated by curing shrinkage. Cobalt naphthenate and zinc naphthenate, as metal accelerators, have long-chain alkyl groups in their molecular structures that can embed between resin molecular chains, playing a role in molecular plasticization. The chelating effect of 2,4-pentanedione optimizes the crosslinking network structure, making the network more uniform and porous, improving the deformability of the molecular chains after curing, thereby enhancing flexibility. This avoids the formation of stress concentration points due to excessive local crosslinking, allowing impact energy to be uniformly transmitted through the network rather than concentrated at defects leading to fracture. It also strengthens interfacial interactions, making it easier for the system to absorb impact energy and improving impact resistance. Detailed Implementation

[0024] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0025] Preparation of desensitizing agents

[0026] Mix 0.5 mol ricinoleic acid, 0.3 mol terephthalic acid, 0.03 mol p-toluenesulfonic acid, and 100 mL toluene. Heat the mixture to 135 °C under a nitrogen atmosphere, reflux and stir for 6 h. Add 0.6 mol isooctyl alcohol and continue stirring for 4 h. When the acid value of the system is ≤5.5 mg KOH / g, discharge the product. Add the obtained product to a separatory funnel and wash with 1 mol / L sodium hydroxide solution, deionized water, and saturated sodium chloride solution (20 °C) until pH=7. Then, rotary evaporate at 70 °C for 4 h to obtain the esterified material.

[0027] Mix 0.55 mol of the esterified material, 0.25 g of phosphoric acid, and 0.17 mol of formic acid, heat to 60 °C, and add 80 mL of 30% hydrogen peroxide solution dropwise while stirring. Continue stirring for 10 h, discharge the material, add the resulting product to a separatory funnel, wash with 1 mol / L sodium hydroxide solution, deionized water, and saturated sodium chloride solution (20 °C) until neutral, and then rotary evaporate at 70 °C for 4 h to obtain the epoxidized esterified material.

[0028] Mix 100g disproportionated rosin, 270mL ethanol, and 30mL deionized water, heat and stir at 55℃ for 30min, add 20g ethanolamine, continue stirring for 2h, then extract with petroleum ether, repeat 4 times, discard the ether layer, cool the salt layer, crystallize, filter, and recrystallize the obtained crystals with 50% ethanol aqueous solution 5 times. Then dissolve the obtained crystals with 50% ethanol aqueous solution, add 1mol / L dilute hydrochloric acid to pH=4, after the precipitate has completely precipitated, filter, wash the precipitate to neutral, collect the washed precipitate and recrystallize with 75% ethanol aqueous solution to obtain dehydrorosin acid;

[0029] Take 57.1g of the dehydrorosin acid and 96.9g of the epoxidized esterified material, mix them, heat to 110℃ in a nitrogen atmosphere and stir for 2h, add 4.61g of benzyltriethylammonium chloride, continue stirring for 2h, then heat to 120℃ and continue stirring for 8h, discharge the material to obtain the desensitizer.

[0030] Example 1

[0031] A method for preparing an environmentally friendly cyclohexanone peroxide curing agent composition includes the following steps:

[0032] S1. Take 80g of hydrogen peroxide with a mass fraction of 30% and 5g of concentrated sulfuric acid with a mass fraction of 98% and mix them to obtain material A;

[0033] S2. Mix 49g of cyclohexanone and 48g of desensitizing agent to obtain material B;

[0034] S3. Add the material B to the material A, stir at 20°C for 1-2 hours, let stand and separate into layers, take the upper oil phase, add 1g of calcium carbonate powder for acid neutralization, add 12g of stabilizer diacetone alcohol and 15g of accelerator, and ultrasonically stir for 8-10 minutes to obtain the environmentally friendly cyclohexanone peroxide curing agent composition.

[0035] The accelerator comprises 2g of 2,4-pentanedione, 8g of 2-methylimidazole, 4g of cobalt naphthenate, and 1g of zinc naphthenate.

[0036] Example 2

[0037] A method for preparing an environmentally friendly cyclohexanone peroxide curing agent composition includes the following steps:

[0038] S1. Take 80g of hydrogen peroxide with a mass fraction of 30% and 5g of concentrated sulfuric acid with a mass fraction of 98% and mix them to obtain material A;

[0039] S2. Mix 49g of cyclohexanone and 48g of desensitizing agent to obtain material B;

[0040] S3. Add material B to material A, stir at 20°C for 1-2 hours, let stand and separate into layers, take the upper oil phase, add 1g of calcium carbonate powder for acid neutralization, add 12g of stabilizer cyclohexanediol and 15g of accelerator, and ultrasonically stir for 8-10 minutes to obtain the environmentally friendly cyclohexanone peroxide curing agent composition.

[0041] The accelerator includes 10g of 2-phenylimidazoline and 5g of cobalt isooctanoate.

[0042] Example 3

[0043] A method for preparing an environmentally friendly cyclohexanone peroxide curing agent composition includes the following steps:

[0044] S1. Take 80g of hydrogen peroxide with a mass fraction of 30% and 5g of concentrated sulfuric acid with a mass fraction of 98% and mix them to obtain material A;

[0045] S2. Mix 49g of cyclohexanone and 48g of desensitizing agent to obtain material B;

[0046] S3. Add material B to material A, stir at 20°C for 1-2 hours, let stand and separate into layers, take the upper oil phase, add 1g of calcium carbonate powder for acid neutralization, add 12g of stabilizer glycerol and 15g of accelerator, and ultrasonically stir for 8-10 minutes to obtain the environmentally friendly cyclohexanone peroxide curing agent composition.

[0047] The accelerator includes 10g of 2,4-pentanedione and 5g of zinc naphthenate.

[0048] Example 4

[0049] The difference from Example 1 is that the preparation method of this environmentally friendly cyclohexanone peroxide curing agent composition includes the following steps:

[0050] S1. Take 80g of hydrogen peroxide with a mass fraction of 30% and 5g of concentrated sulfuric acid with a mass fraction of 98% and mix them to obtain material A;

[0051] S2. Mix 49g of cyclohexanone and 48g of dioctyl phthalate to obtain material B;

[0052] S3. Add the material B to the material A, stir at 20°C for 1-2 hours, let stand and separate into layers, take the upper oil phase, add 1g of calcium carbonate powder for acid neutralization, add 12g of stabilizer diacetone alcohol and 15g of accelerator, and ultrasonically stir for 8-10 minutes to obtain the environmentally friendly cyclohexanone peroxide curing agent composition.

[0053] The accelerator comprises 2g of 2,4-pentanedione, 8g of 2-methylimidazole, 4g of cobalt naphthenate, and 1g of zinc naphthenate.

[0054] Example 5

[0055] The difference from Example 1 is that the preparation method of this environmentally friendly cyclohexanone peroxide curing agent composition includes the following steps:

[0056] S1. Take 80g of hydrogen peroxide with a mass fraction of 30% and 5g of concentrated sulfuric acid with a mass fraction of 98% and mix them to obtain material A;

[0057] S2. Take 97g of cyclohexanone and add it to the material A. Stir at 20°C for 1-2 hours, let it stand and separate into layers. Take the upper oil phase and add 1g of calcium carbonate powder for acid neutralization. Add 12g of stabilizer diacetone alcohol and 15g of accelerator. Stir ultrasonically for 8-10 minutes to obtain the environmentally friendly cyclohexanone peroxide curing agent composition.

[0058] The accelerator comprises 2g of 2,4-pentanedione, 8g of 2-methylimidazole, 4g of cobalt naphthenate, and 1g of zinc naphthenate.

[0059] Application Example 1

[0060] A type of high-speed rail putty, comprising:

[0061] Component A, 100 parts by weight;

[0062] Component B is 3 parts by weight;

[0063] Component A includes:

[0064] Atomic gray unsaturated polyester resin XJ-668A (Zhejiang Xinji Composite Materials Co., Ltd.) 35 parts by weight; BYK966 dispersant 0.4 parts by weight; BYK057 defoamer 0.2 parts by weight; styrene 5 parts by weight; titanium dioxide 3 parts by weight; talc filler 30 parts by weight; kaolin filler 20 parts by weight;

[0065] Component B is the environmentally friendly cyclohexanone peroxide curing agent composition prepared in Example 1.

[0066] Application Example 2

[0067] A type of high-speed rail putty, comprising:

[0068] Component A, 100 parts by weight;

[0069] Component B is 3 parts by weight;

[0070] Component A includes:

[0071] Atomic gray unsaturated polyester resin XJ-668A (Zhejiang Xinji Composite Materials Co., Ltd.) 35 parts by weight; BYK966 dispersant 0.4 parts by weight; BYK057 defoamer 0.2 parts by weight; styrene 5 parts by weight; titanium dioxide 3 parts by weight; talc filler 30 parts by weight; kaolin filler 20 parts by weight;

[0072] Component B is the environmentally friendly cyclohexanone peroxide curing agent composition prepared in Example 2.

[0073] Application Example 3

[0074] A type of high-speed rail putty, comprising:

[0075] Component A, 100 parts by weight;

[0076] Component B is 3 parts by weight;

[0077] Component A includes:

[0078] Atomic gray unsaturated polyester resin XJ-668A (Zhejiang Xinji Composite Materials Co., Ltd.) 35 parts by weight; BYK966 dispersant 0.4 parts by weight; BYK057 defoamer 0.2 parts by weight; styrene 5 parts by weight; titanium dioxide 3 parts by weight; talc filler 30 parts by weight; kaolin filler 20 parts by weight;

[0079] Component B is the environmentally friendly cyclohexanone peroxide curing agent composition prepared in Example 3.

[0080] Application Example 4

[0081] A type of high-speed rail putty, comprising:

[0082] Component A, 100 parts by weight;

[0083] Component B is 3 parts by weight;

[0084] Component A includes:

[0085] Atomic gray unsaturated polyester resin XJ-668A (Zhejiang Xinji Composite Materials Co., Ltd.) 35 parts by weight; BYK966 dispersant 0.4 parts by weight; BYK057 defoamer 0.2 parts by weight; styrene 5 parts by weight; titanium dioxide 3 parts by weight; talc filler 30 parts by weight; kaolin filler 20 parts by weight;

[0086] Component B is the environmentally friendly cyclohexanone peroxide curing agent composition prepared in Example 4.

[0087] Application Example 5

[0088] A type of high-speed rail putty, comprising:

[0089] Component A, 100 parts by weight;

[0090] Component B is 3 parts by weight;

[0091] Component A includes:

[0092] Atomic gray unsaturated polyester resin XJ-668A (Zhejiang Xinji Composite Materials Co., Ltd.) 35 parts by weight; BYK966 dispersant 0.4 parts by weight; BYK057 defoamer 0.2 parts by weight; styrene 5 parts by weight; titanium dioxide 3 parts by weight; talc filler 30 parts by weight; kaolin filler 20 parts by weight;

[0093] Component B is the environmentally friendly cyclohexanone peroxide curing agent composition prepared in Example 5.

[0094] Performance testing

[0095] The high-iron putty obtained by mixing components A and B of Application Examples 1-5 was applied to the surface of the insulating glass and the following performance tests were conducted. The test results are shown in Table 1.

[0096] 1) Under constant temperature conditions of 25℃, the gelation time was determined manually (using t). g (This is indicated by the symbol), see GB / T 7193-2008 Determination of gel time of unsaturated polyester resin at 25℃.

[0097] 2) The flexibility was determined according to the standard GB / T 1748-1979 "Test Method for Flexibility of Putty Film".

[0098] 3) The impact strength was determined according to the standard GB / T 1732-2020 "Test Method for Impact Resistance of Coating Film".

[0099] Table 1

[0100]

[0101] As shown in Table 1, compared with Application Examples 4 and 5, the curing agent composition in Application Example 1 uses a self-made desensitizing agent, which to some extent replaces phthalate desensitizing agents, delays curing time, and can improve the product performance of putty to some extent.

[0102] Compared to Application Examples 2 and 3, the curing agent composition in Application Example 1, combined with the stabilizer diacetone alcohol and the accelerator components consisting of 2,4-pentanedione, 2-methylimidazole, cobalt naphthenate, and zinc naphthenate, has a more suitable gel time, which improves the product performance of the putty to a certain extent.

[0103] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. The application of an environmentally friendly cyclohexanone peroxide curing agent composition in high-iron putty, characterized in that, The preparation method of the environmentally friendly cyclohexanone peroxide curing agent composition includes the following steps: A1. Using ricinoleic acid, terephthalic acid, and isooctanol as reactants, an esterification reaction is carried out under the catalysis of a catalyst to obtain the esterified material; the catalyst is p-toluenesulfonic acid. A2. The esterified material is subjected to epoxidation treatment to obtain an epoxidized esterified material; A3. Using dehydrorosin acid and epoxidized esterified materials as reactants, a ring-opening reaction is carried out to obtain a desensitizing agent; A4. Mix hydrogen peroxide and inorganic acid to obtain material A; the inorganic acid is selected from any one of sulfuric acid, hydrochloric acid and nitric acid; A5. Mix cyclohexanone and the desensitizing agent to obtain material B; A6. Add material B to material A, stir at 20°C for 1-2 hours, allow to stand and separate into layers, take the upper oil phase for acid neutralization, add stabilizer and accelerator, stir evenly, and obtain the environmentally friendly cyclohexanone peroxide curing agent composition; the stabilizer is diacetone alcohol; the accelerator is composed of 2,4-pentanedione, 2-methylimidazole, cobalt naphthenate and zinc naphthenate; The preparation method of the desensitizing agent specifically includes the following steps: Mix 0.5 mol ricinoleic acid, 0.3 mol terephthalic acid, 0.03 mol p-toluenesulfonic acid, and 100 mL toluene; heat to 135°C under a nitrogen atmosphere; reflux and stir for 6 hours; add 0.6 mol isooctyl alcohol; continue stirring for 4 hours; when the acid value of the system is ≤5.5 mg... When KOH / g is present, the product is discharged and added to a separatory funnel. It is washed with 1 mol / L sodium hydroxide solution, deionized water, and saturated sodium chloride solution at 20°C until pH=7. Then, it is rotary evaporated at 70°C for 4 hours to obtain the esterified material. 0.55 mol of the esterified material, 0.25 g of phosphoric acid, and 0.17 mol of formic acid are mixed and heated to 60°C. While stirring, 80 mL of 30% hydrogen peroxide solution is added dropwise, and stirring is continued for 10 hours. The product is discharged and added to a separatory funnel. It is washed with 1 mol / L sodium hydroxide solution, deionized water, and saturated sodium chloride solution at 20°C until neutral. Then, it is rotary evaporated at 70°C for 4 hours to obtain the epoxidized esterified material. 100 g of disproportionated rosin, 270 mL of ethanol, and 30 mL of deionized water are mixed and heated and stirred at 55°C. After 30 minutes, 20 g of ethanolamine was added, and stirring was continued for 2 hours. Then, extraction was performed using petroleum ether, repeated 4 times. The ether layer was discarded, the salt layer was cooled, crystallized, and filtered. The obtained crystals were recrystallized 5 times with a 50% ethanol aqueous solution. The crystals were then dissolved with a 50% ethanol aqueous solution, and 1 mol / L dilute hydrochloric acid was added to pH=4. After the precipitate was completely precipitated, it was filtered and washed until neutral. The washed precipitate was collected and recrystallized with a 75% ethanol aqueous solution to obtain dehydrorosin acid. 57.1 g of the dehydrorosin acid and 96.9 g of the epoxidized esterified material were mixed and heated to 110 °C in a nitrogen atmosphere and stirred for 2 hours. 4.61 g of benzyltriethylammonium chloride was added, and stirring was continued for 2 hours. Then, the temperature was raised to 120 °C and stirring was continued for 8 hours. The product was discharged to obtain the desensitizing agent.

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