Preparation method and application of epsilon-caprolactone modified epoxy resin
阅读说明：本技术 一种ε-己内酯改性环氧树脂的制备方法及应用 (Preparation method and application of epsilon-caprolactone modified epoxy resin ) 是由 高伟 李镓豪 王湘杰 陶志豪 彭友智 彭涛 于 2021-07-20 设计创作，主要内容包括：本发明公开了一种ε-己内酯改性环氧树脂的制备方法及应用,将ε-己内酯加入到环氧树脂中,得到改性后的环氧树脂,将改性后的环氧树脂中加入异氰酸酯反应一段时间后加入聚己内酯多元醇,将得到的产品和固化剂混合后刮涂在PET膜上,得到无溶剂型的PET薄膜涂层。本发明采用了羟基接枝ε-己内酯的方法,从环氧树脂上的分子结构上解决了增韧的问题,并且利用聚氨酯对环氧树脂再改性,改善了环氧树脂的脆性和拉伸不足的缺点。(The invention discloses a preparation method and application of epsilon-caprolactone modified epoxy resin. The invention adopts a method of hydroxyl grafting epsilon-caprolactone, solves the toughening problem from the molecular structure of the epoxy resin, and improves the defects of brittleness and insufficient stretching of the epoxy resin by utilizing polyurethane to modify the epoxy resin.)
1. The epsilon-caprolactone modified epoxy resin is characterized in that the chemical structural formula is as follows:
wherein m is 1-10, n is 1-10, Y is 1-10, and Z is 1-10.
2. The organic gas treatment device according to claim 1, wherein the epsilon-caprolactone-modified epoxy resin has a viscosity of 9000-15000mpa.s at 25 ℃.
3. The preparation method of the epsilon-caprolactone modified epoxy resin is characterized by comprising the following steps:
s1: weighing epoxy resin and epsilon-caprolactone, wherein the mass ratio of the epsilon-caprolactone to the epoxy resin is 11-54: 100, respectively;
s2: putting epoxy resin into a reaction container to perform first dehydration treatment;
s3: adding epsilon-caprolactone into the reaction vessel for second dehydration treatment;
s4: adding a catalyst into the reaction container for reaction, wherein nitrogen positive pressure protection is used in the reaction process;
s5: and after the reaction in S4 is finished, carrying out reduced pressure distillation to obtain an epsilon-caprolactone modified epoxy resin product, wherein the chemical formula of the epsilon-caprolactone modified epoxy resin product is as follows:
wherein m is 1-10, n is 1-10, Y is 1-10, and Z is 1-10.
4. The process for producing an epsilon-caprolactone-modified epoxy resin as claimed in claim 3, wherein the first dehydration treatment is carried out at a dehydration temperature of 70 to 80 ℃, a dehydration vacuum degree of- (90 to 99) KPa and a dehydration time of 2 to 4 hours; the vacuum is eliminated by nitrogen in the whole process of the second dehydration treatment; the reaction temperature of the reduced pressure distillation is 140-155 ℃, and the reaction time is 2-4 h; the reaction temperature of the step S4 is 140-180 ℃, and the reaction time is 4-6 h.
5. The method for preparing epsilon-caprolactone modified epoxy resin as claimed in claim 3, wherein the catalyst in step S4 is stannous octoate and dihydroxy butyl tin chloride, the dosage of stannous octoate is 300-500ppm, and the dosage of dihydroxy butyl tin chloride is 30-100 ppm.
6. An application method of epsilon-caprolactone modified epoxy resin on a PET film is characterized by comprising the following steps:
step one, obtaining polyurethane modified epoxy resin:
l1: adding epsilon-caprolactone modified epoxy resin into a reaction container for vacuum dehydration, wherein the epsilon-caprolactone modified epoxy resin has the following structure:
wherein m is 1-10, n is 1-10, Y is 1-10, Z is 1-10;
l2: keeping the temperature of the reaction vessel below 50 ℃, stirring by adopting an anchor stirring paddle in the reaction process, and adding isocyanate, wherein the mass ratio of the added isocyanate to the epsilon-caprolactone modified epoxy resin is as follows: 9.23-28.87: 100, reacting isocyanate with epsilon-caprolactone modified epoxy resin;
l3: adding polycaprolactone polyol after the reaction in the step L2, wherein the addition amount of the polycaprolactone polyol is 42-132 g, and the product obtained after the reaction is polyurethane modified epoxy resin;
step two, obtaining a solvent-free PET film coating:
m1: mixing polyurethane modified epoxy resin with a curing agent, wherein the dosage of the curing agent is calculated according to the formula:
obtaining a mixture of polyurethane modified epoxy resin and a curing agent;
m2: and (3) coating the mixture on a PET film by scraping, and carrying out curing treatment at the temperature of 40-60 ℃ for not less than 15min to obtain the PET film coating.
7. The method for applying the epsilon-caprolactone modified epoxy resin to the PET film as claimed in claim 6, wherein the curing agent is one of a polyamide curing agent and a polyetheramine curing agent; the isocyanate is one of TDI, MDI and HDI.
8. The method of claim 7, wherein the amount of the curing agent is calculated according to epoxy equivalent and epoxy value of the epsilon-caprolactone-modified epoxy resin, the epoxy equivalent is determined by hydrochloric acid-acetone method, the epoxy value is 1/epoxy equivalent x 100, and the ratio of the epoxy resin to the curing agent is calculated according to epoxy equivalent and active hydrogen equivalent:
the grams G ═ active hydrogen equivalents x epoxy number of the epoxy resin of 100G of added amine.
9. The method for applying the epsilon-caprolactone modified epoxy resin to the PET film as claimed in claim 6, wherein the temperature of the vacuum dehydration is 70-80 ℃; the reaction temperature of the L2 was 65-90 ℃.
Technical Field
The invention relates to the field of organic high molecular compounds, in particular to a preparation method and application of epsilon-caprolactone modified epoxy resin.
Background
Epoxy resin is an important thermosetting resin and is widely applied to the fields of adhesives, composite materials, coatings and the like. The epoxy resin can have excellent thermal property and mechanical strength after being cured by amine, anhydride and other curing agents. However, the pure epoxy resin forms a highly crosslinked three-dimensional network structure after being cured, and molecular chains are not easy to slide, so that the cured resin is brittle and has poor impact toughness, which is not enough to meet the requirements of engineering technology, and the application range is limited. In order to ensure the practical application of epoxy resin, the toughening modification of the epoxy resin becomes an important research direction
A common toughening modification method for epoxy resins (EP) is toughening of liquid rubbers, including carboxyl-terminated, amino-terminated (ATBN), epoxy-terminated (ETBN) and vinyl-terminated (VTBN) nitrile rubbers. The mechanism of toughening epoxy is as follows: the rubber is uniformly distributed in the EP matrix, micro-phase separation is carried out in the EP curing and crosslinking process to form a sea-island structure with EP as a continuous phase and the rubber elastomer as a dispersed phase, and when the modified EP is impacted by external force, the dispersed phase rubber induces the formation of silver lines and shear bands and absorbs partial energy to achieve the aim of toughening. However, it is often difficult to achieve uniform dispersion in practice, and the viscosity of the system is further increased.
In some industries, a flexible chain segment curing agent is adopted to toughen epoxy resin for convenient processing, and a macromolecular curing agent containing a flexible chain segment toughens the epoxy resin, wherein the flexible chain segment can be bonded into a compact epoxy resin crosslinking network, and micro-phase separation is generated in the curing process to form a compact and loose phase two-phase network structure, so that the effects of dispersing stress and promoting the plastic deformation in the material are achieved, the toughness of an epoxy system is improved, and the forming process is simplified while the toughness of the epoxy resin is improved. The flexible chain segment curing agent can reduce other performances to different degrees while toughening the epoxy resin, such as poor adhesion, poor thermal stability and the like, and the glue is easy to fall off after being cured and easy to deform after being heated.
The Polyurethane (PU) is a high polymer material which is generated by the reaction of isocyanate and polycaprolactone polyol and contains a flexible chain segment and a carbamate group in a molecular chain, has good toughness and wear resistance, can be used as a modified toughening agent and added into EP, and can greatly improve the toughness and wear resistance of epoxy resin after being cured. The epoxy resin modified by caprolactone converts secondary hydroxyl on the original chain segment into primary hydroxyl on the branched chain, and the reactivity of the primary hydroxyl and isocyanate in the field of polyurethane is far higher than that of the secondary hydroxyl and isocyanate, so that the epoxy resin modified by caprolactone can react with isocyanate quickly, and the production efficiency is improved.
Meanwhile, in some electronic fields, exothermic peaks during curing need to be reduced, so that the situation that the appearance is completely cured due to the fact that the exothermic is too violent is prevented, but the whole performance is greatly reduced due to the fact that a large amount of curing agents and epoxy resin are not cured in the electronic fields, and the requirements of working conditions cannot be met.
Therefore, it is required to develop a modified epoxy resin having a small viscosity, good fluidity, strong impact resistance and a greatly reduced exothermic peak.
In the application field, the packaging is the largest non-fiber application market of polyester and is also the fastest growing field of PET, and the PET film is the most commonly used film in industrial production and daily life. However, the use of PET films is limited because PET films are not scratch-resistant and have low hardness, and the current solution is to improve the problem by coating a coating on the PET film.
The coating of the current PET film is solvent type, the emission of Volatile Organic Compounds (VOC) is high, most of the VOC is toxic volatile matters, and meanwhile, the coating has poor hardness, unsatisfactory scratch resistance effect, low impact strength and poor high-temperature and high-humidity resistance, and causes harm to human bodies and the environment while limiting application scenes. Therefore, the development of the coating which is environment-friendly, has good binding force with PET, effectively improves the hardness of the PET film, and improves the scratch resistance and the tensile property has important significance.
Disclosure of Invention
In order to solve the problems, the invention discloses a preparation method and application of epsilon-caprolactone modified epoxy resin,
in order to achieve the purpose, the technical scheme of the invention is as follows:
the epsilon-caprolactone modified epoxy resin has the following chemical structure:
wherein m is 1-10, n is 1-10, Y is 1-10, and Z is 1-10.
In a further improvement, the viscosity of the epsilon-caprolactone modified epoxy resin at 25 ℃ is 9000-15000 mpa.s.
The preparation method of the epsilon-caprolactone modified epoxy resin comprises the following steps:
s1: weighing epoxy resin and epsilon-caprolactone, wherein the mass ratio of the epsilon-caprolactone to the epoxy resin is 11-54: 100, respectively;
s2: putting epoxy resin into a reaction container to perform first dehydration treatment;
s3: adding epsilon-caprolactone into the reaction vessel for second dehydration treatment;
s4: adding a catalyst into the reaction container for reaction, wherein nitrogen positive pressure protection is used in the reaction process;
s5: and after the reaction in S4 is finished, carrying out reduced pressure distillation to obtain an epsilon-caprolactone modified epoxy resin product, wherein the chemical formula of the epsilon-caprolactone modified epoxy resin product is as follows:
wherein m is 1-10, n is 1-10, Y is 1-10, and Z is 1-10.
The further improvement is that the dehydration temperature of the first dehydration treatment is 70-80 ℃, the dehydration vacuum degree is- (90-99) KPa, and the dehydration time is 2-4 h; the vacuum is eliminated by nitrogen in the whole process of the second dehydration treatment; the reaction temperature of the reduced pressure distillation is 140-155 ℃, and the reaction time is 2-4 h; the reaction temperature of the step S4 is 140-180 ℃, and the reaction time is 4-6 h.
In a further improvement, the catalyst in the step S4 is stannous octoate and dihydroxy butyl tin chloride, the dosage of the stannous octoate is 300-500ppm, and the dosage of the dihydroxy butyl tin chloride is 30-100 ppm.
An application method of epsilon-caprolactone modified epoxy resin on a PET film comprises the following steps:
step one, obtaining polyurethane modified epoxy resin:
l1: adding epsilon-caprolactone modified epoxy resin into a reaction container for vacuum dehydration, wherein the epsilon-caprolactone modified epoxy resin has the following structure:
wherein m is 1-10, n is 1-10, Y is 1-10, Z is 1-10;
l2: keeping the temperature of the reaction vessel below 50 ℃, stirring by adopting an anchor stirring paddle in the reaction process, and adding isocyanate, wherein the mass ratio of the added isocyanate to the epsilon-caprolactone modified epoxy resin is as follows: 9.23-28.87: 100, reacting isocyanate with epsilon-caprolactone modified epoxy resin;
l3: adding polycaprolactone polyol after the reaction in the step L2, wherein the addition amount of the polycaprolactone polyol is 42-132 g, and the product obtained after the reaction is polyurethane modified epoxy resin;
step two, obtaining a solvent-free PET film coating:
m1: mixing polyurethane modified epoxy resin with a curing agent, wherein the dosage of the curing agent is calculated according to the formula:
obtaining a mixture of polyurethane modified epoxy resin and a curing agent;
m2: and (3) coating the mixture on a PET film by scraping, and carrying out curing treatment at the temperature of 40-60 ℃ for not less than 15min to obtain the PET film coating.
The further improvement is that the curing agent is one of polyamide curing agent and polyether amine curing agent; the isocyanate is one of TDI, MDI and HDI.
In a further improvement, the amount of the curing agent is calculated according to the epoxy equivalent and the epoxy value of the epsilon-caprolactone modified epoxy resin, the epoxy equivalent is detected by a hydrochloric acid-acetone method, the epoxy value is 1/epoxy equivalent multiplied by 100, and the ratio of the epoxy resin to the curing agent is calculated according to the epoxy equivalent and the active hydrogen equivalent:
the grams G ═ active hydrogen equivalents x epoxy number of the epoxy resin of 100G of added amine.
The concrete steps of the hydrochloric acid-acetone method are as follows:
accurately weighing about 0.3g (accurate to 0.0001g) of a sample, placing the sample into a 250ml triangular flask with a plug and a ground opening, accurately adding 10ml of acetone hydrochloride solution, sealing the plug, shaking up, placing the sample in a dark place, standing for 60 minutes to determine that the sample is completely dissolved, adding two drops of phenolphthalein indicator, titrating the sample to pink by using a calibrated NaOH-C2H5OH standard solution, titrating the sample in parallel for three times, and simultaneously performing a blank experiment for three times
Calculation of epoxy equivalent:
concentration of NaOH-C2H5OH
V1: NaOH-C2H5OH volume consumed in blank experiment by hydrochloric acid-acetone method
V2: NaOH-C2H5OH volume consumed by test specimens in the hydrochloric acid-acetone method
m mass of sample
In a further improvement, the temperature of the vacuum dehydration is 70-80 ℃; the reaction temperature of the L2 was 65-90 ℃.
The invention has the advantages that:
1. according to the invention, the soft long aliphatic chain segment is introduced to the secondary hydroxyl of the bisphenol A epoxy resin, so that the proportion of a rigid structure in the whole molecular chain segment is reduced, the conjugation of a large pi bond between two benzene rings is weakened, the steric hindrance is reduced, and the cured epoxy resin has better toughness;
2. the epoxy resin modified by polyurethane is used as a solvent-free coating, so that the emission of Volatile Organic Compounds (VOC) can be greatly reduced during curing, and the hardness, scratch resistance, impact strength, high temperature and high humidity resistance of the curing coating are obviously improved compared with those of the common solvent-based coating.
3. The ester bond in the structure can absorb the heat generated in the epoxy resin curing process, thereby achieving the purpose of reducing the exothermic peak during epoxy curing and meeting the requirements of the electronic encapsulation industry.
Detailed Description
The present invention is further illustrated by the following examples.
Example 1
The method comprises the steps of filling 800g of epoxy resin E51 (containing 2mol of epoxy groups) into a 1L four-neck flask provided with a magneton, a thermometer and a vacuum receiving tube, heating to 70 ℃, dehydrating in vacuum with the vacuum degree of-90 KPa and the dehydration time of 2h, reducing the temperature to 50 ℃, adding 88g of epsilon-caprolactone, uniformly mixing, heating to 55 ℃, dehydrating for 3h under the same vacuum degree, then adding 300ppm of stannous octoate catalyst, replacing for three times by nitrogen, heating to 180 ℃, reacting for 4h at the temperature, sampling for 3h after reaction, measuring the viscosity, sampling for one time every hour, and recording data (taking care that nitrogen is necessarily introduced when sampling is carried out, so that oxygen is prevented from entering and becoming yellow during sampling). After 6h the viscosity was 11000mpa.s and the caprolactone residue was 0.97%. The temperature is reduced to 140 ℃, the mixture is kept for 2h under the vacuum degree of-99 KPa, the final viscosity is 12100mpa.s, and the epoxy equivalent is 210. The epoxy resin used in this example was CYD-128, the hydroxyl group content was 0.14mol, the hydroxyl group content was 0.05mol per 1 CYD-128 epoxy resin, so m was 2.8, the caprolactone content was 0.77mol, if all grafted, the epoxy equivalent was 210, and the hydroxyl group content of all grafted epoxy resins was 0.28mol, so n was 2.75.
And (3) performance measurement:
the advantages of the caprolactone-modified epoxy resin are judged by comparing the data of the resin before and after modification on viscosity, impact strength and the like through proportioning and curing with a polyamide curing agent 650 (the active hydrogen equivalent of the polyamide 650 curing agent is 185).
In this example, 50g of e51 and H52 were respectively taken, and the corresponding polyamide 650 curing agents were weighed according to the method in claim 8, i.e., 50g of e51 epoxy resin was mixed with 47g of polyamide 650, and 50g of H52 modified epoxy resin was mixed with 43g of polyamide 650, and after mixing, the mixture was poured into a mold and cured at 50 ℃, and then sliced for data detection. Table 1 shows a comparison of two data before and after modification of the epoxy resin.
TABLE 1
As can be seen from Table 1, the caprolactone-modified epoxy resin has a low viscosity at normal temperature, and the impact strength after curing is greatly improved.
Preparation and performance of the solvent-free PET film coating:
adding 150g H52 into a four-neck flask provided with a stirring paddle, a thermometer and a condenser, dehydrating for 1h under vacuum at 70 ℃, then reducing the temperature to about 50 ℃, adding 20.6g of MDI, raising the temperature to 90 ℃ after the temperature is stabilized, adding 121g of 1000-molecular-weight polycaprolactone polyol after reacting for 3h, continuing to react for 3h, and reducing the temperature and taking out the product. The final epoxy equivalent weight tested was 410 and the designed epoxy equivalent weight was 411, at which time the polyol was fully grafted. Normally, the degree of aggregation is the same at both ends of 1000 molecular weight polycaprolactone polyol, so X ═ Y ═ 3.9.
Taking 50g of polyurethane modified epoxy resin, adding 7.6g of polyetheramine curing agent according to the calculation method in claim 8, uniformly mixing, blade-coating on a PET film, and curing for 15min at 45 ℃. And adding 15.5g of polyetheramine curing agent into 50g of E51, uniformly mixing, blade-coating on a PET film, and curing for 15min at 45 ℃. And comparing the tensile strength, the wear resistance and the adhesive force of the two epoxy resins, and judging whether the two epoxy resins have the phenomenon of fogging or degumming after-15-80 ℃ cold-hot circulation for one week. Table 2 shows the comparison result of the above data.
TABLE 2
From table 2, it can be seen that the overall performance of the polyurethane-modified H52 is greatly improved, and the tensile strength of H52 is 37mpa, which is far higher than that of conventional E51. Good adhesive force, no degumming and fogging phenomenon after one week of cold-hot cycle experiment, and the impact strength of 28.6KJ/m2The lifting effect is obvious compared with E51.
Example 2
The method comprises the steps of filling 600g of epoxy resin E51 (containing 2mol of epoxy groups) into a 1L four-neck flask provided with a magneton, a thermometer and a vacuum receiving tube, heating to 80 ℃ and dehydrating in vacuum with the vacuum degree of-99 KPa and the dehydration time of 2h, reducing the temperature to 50 ℃, adding 300g of epsilon-caprolactone, uniformly mixing, heating to 55 ℃, dehydrating for 3h under the same vacuum degree, adding 500ppm of stannous octoate catalyst, replacing for three times by nitrogen, heating to 165 ℃, reacting for 6h at the temperature, sampling for 3h after reacting, measuring the viscosity, sampling for one time every hour, and recording data (taking care that nitrogen is necessarily introduced when sampling is carried out, so that oxygen is prevented from entering and becoming yellow during sampling). After 6h the viscosity was 11460mpa.s with 1.03% caprolactone residue. The temperature is reduced to 150 ℃, the mixture is kept for 2h under the vacuum degree of-99 KPa, the final viscosity is 12780mpa.s, and the epoxy equivalent is 253. The epoxy resin used in this example was CYD-128, the hydroxyl group content was 0.14mol, the hydroxyl group content was 0.05mol per 1 CYD-128 epoxy resin, so m was 2.8, the caprolactone content was 2.63mol, the epoxy equivalent was 285 if all grafted, and the hydroxyl group content was 0.28mol after all grafted, so n was 9.3.
And (3) performance measurement:
the advantages of the caprolactone modified epoxy resin are judged by comparing the data of the resin before and after modification in the aspects of viscosity, impact strength and the like through proportioning and curing with the polyamide curing agent 650.
In this example, 50g of E51 and H52 were taken, and the corresponding curing agents for polyamide 650, namely 50g of E51 epoxy resin was mixed with 47g of polyamide 650, and 50g of H52 modified epoxy resin was mixed with 36.5g of polyamide 650, and after mixing, the mixture was poured into a mold and cured at 50 ℃ and sliced for data detection, were weighed according to the method of claim 8. Table 3 is a comparison of the two data before and after the epoxy resin modification.
TABLE 3
As can be seen from table 3, the caprolactone-modified epoxy resin had an increased viscosity at room temperature but had no influence on the flowability, and the impact strength after curing was greatly improved.
Preparation and performance of the solvent-free PET film coating:
adding 150g H52 into a four-neck flask provided with a stirring paddle, a thermometer and a condenser, dehydrating for 1h at 75 ℃, then reducing the temperature to about 50 ℃, adding 30.1g of TDI, raising the temperature to 90 ℃ after the temperature is stable, adding 42g of polycaprolactone polyol with the molecular weight of 400 after reacting for 3h, continuing to react for 3h, and reducing the temperature and taking out the polycaprolactone polyol. The final epoxy equivalent weight tested was 422, the epoxy equivalent weight was designed to be 422, at which point the polyol was fully grafted. Normally, the degree of aggregation is the same at both ends of 400 molecular weight polycaprolactone polyol, so X ═ Y ═ 1.35.
50g of polyurethane modified epoxy resin is taken, 10.1g of polyether amine curing agent is added, the mixture is evenly mixed and then blade-coated on a PET film, and the mixture is cured for 15min at the temperature of 45 ℃. And adding 15.5g of polyetheramine curing agent into 50g of E51, uniformly mixing, blade-coating on a PET film, and curing for 15min at 45 ℃. And comparing the tensile strength, the wear resistance and the adhesive force of the two epoxy resins, and judging whether the two epoxy resins have the phenomenon of fogging or degumming after-15-80 ℃ cold-hot circulation for one week. Table 4 shows the comparison result of the above data.
TABLE 4
As can be seen from Table 4, the overall performance of the polyurethane-modified H52 is greatly improved, and the tensile strength of H52-2 is 45mpa, which is far higher than that of conventional E51. Good adhesive force, no degumming and fogging phenomenon after one week of cold-hot cycle experiment, and the impact strength of 31.7KJ/m2The lifting effect is obvious compared with E51.
Example 3
The method comprises the steps of filling 600g of epoxy resin E51 (containing 2mol of epoxy groups) into a 1L four-neck flask provided with a magneton, a thermometer and a vacuum receiving tube, heating to 80 ℃ and dehydrating in vacuum with the vacuum degree of-98 KPa and the dehydration time of 2h, reducing the temperature to 50 ℃, adding 200g of epsilon-caprolactone, uniformly mixing, heating to 55 ℃, dehydrating for 3h under the same vacuum degree, adding 400ppm of stannous octoate catalyst, replacing for three times by nitrogen, heating to 140 ℃, reacting for 6h at the temperature, sampling for 3h, measuring the viscosity, sampling for one hour, measuring the viscosity, and recording data (taking care that nitrogen is necessarily introduced when sampling is carried out, and preventing oxygen from entering into the flask to cause yellowing during sampling). After 6h the viscosity was 11850mpa.s with 1.08% caprolactone residue. The temperature is reduced to 140 ℃, the mixture is kept for 2h under the vacuum degree of-99 KPa, the final viscosity is 12765mpa.s, and the epoxy equivalent is 254. The epoxy resin used in this example was CYD-128, the hydroxyl group content was 0.14mol, the hydroxyl group content was 0.05mol per 1 CYD-128 epoxy resin, so m was 2.8, the caprolactone content was 1.74mol, the epoxy equivalent was 254 if all grafted, and the hydroxyl group content was 0.28mol after all grafted, so n was 6.2.
And (3) performance measurement:
the advantages of the caprolactone modified epoxy resin are judged by comparing the data of the resin before and after modification in the aspects of viscosity, impact strength and the like through proportioning and curing with the polyamide curing agent 650.
In this example, 50g of E51 and H52 were taken, and the corresponding curing agents for polyamide 650, namely 50g of E51 epoxy resin was mixed with 47g of polyamide 650, and 50g of H52 modified epoxy resin was mixed with 36.4g of polyamide 650, and after mixing, the mixture was poured into a mold and cured at 50 ℃ and sliced for data detection, were weighed according to the method of claim 8. Table 5 compares the two data before and after the epoxy resin modification.
TABLE 5
As can be seen from table 5, the caprolactone-modified epoxy resin had an increased viscosity at room temperature but had no influence on the flowability, and the impact strength after curing was greatly improved.
Preparation and performance of the solvent-free PET film coating:
adding 150g H52-2 into a four-neck flask provided with a stirring paddle, a thermometer and a condenser, dehydrating for 1h under vacuum at 75 ℃, then reducing the temperature to about 50 ℃, adding 43.3g of MDI, raising the temperature to 90 ℃ after the temperature is stabilized, adding 57g of 400-molecular-weight polycaprolactone polyol after reacting for 3h, continuing to react for 3h, and then reducing the temperature and taking out the product. The final epoxy equivalent weight tested was 423 and the designed epoxy equivalent weight was 424, at which point the polyol was fully grafted. Normally, the degree of aggregation is the same at both ends of 400 molecular weight polycaprolactone polyol, so X ═ Y ═ 1.35.
50g of polyurethane modified epoxy resin is taken, 10.4g of polyetheramine curing agent is added, the mixture is evenly mixed and then blade-coated on a PET film, and the mixture is cured for 15min at the temperature of 45 ℃. And adding 15.5g of polyetheramine curing agent into 50g E51, uniformly mixing, then blade-coating on a PET film, and curing for 15min at 45 ℃. And comparing the tensile strength, the wear resistance and the adhesive force of the two epoxy resins, and judging whether the two epoxy resins have the phenomenon of fogging or degumming after-15-80 ℃ cold-hot circulation for one week. Table 6 shows the comparison of the above data.
TABLE 6
From Table 6, it can be seen that the overall performance of the polyurethane-modified H52 is greatly improved, and the tensile strength of H52 is 48mpa, which is far higher than that of conventional E51. Good adhesive force, no degumming and fogging phenomenon after one week of cold-hot cycle experiment, and the impact strength of the paint is 32.6KJ/m2The lifting effect is obvious compared with E51.
Example 4
The method comprises the steps of filling 500g of epoxy resin E51 (containing 2mol of epoxy groups) into a 1L four-neck flask provided with a magneton, a thermometer and a vacuum receiving tube, heating to 70 ℃, dehydrating in vacuum with the vacuum degree of-99 KPa and the dehydration time of 4h, reducing the temperature to 50 ℃, adding 270g of epsilon-caprolactone, uniformly mixing, heating to 55 ℃, dehydrating for 3h under the same vacuum degree, adding 500ppm of stannous octoate catalyst, replacing for three times with nitrogen, heating to 150 ℃, reacting for 6h at the temperature, sampling for 3h after reaction, measuring the viscosity, sampling for one time every hour, and recording data (taking care that nitrogen is necessarily introduced when sampling is carried out, so that oxygen is prevented from entering and becoming yellow during sampling). After 6h the viscosity was 12450mpa.s and the caprolactone residue was 1.56%. The temperature was reduced to 150 ℃ and maintained at-99 KPa vacuum for 2h, the final viscosity was 13395mpa.s, and the epoxy value was 285. The epoxy resin used in this example was CYD-128, the hydroxyl group content was 0.14mol, the hydroxyl group content was 0.05mol per 1 CYD-128 epoxy resin, so m was 2.8, the caprolactone content was 2.36mol, the epoxy equivalent was 284 if all grafted, and the hydroxyl group content of the epoxy resin after all grafted was 0.28mol, so n was 8.4.
And (3) performance measurement:
the advantages of the caprolactone modified epoxy resin are judged by comparing the data of the resin before and after modification in the aspects of viscosity, impact strength and the like through proportioning and curing with the polyamide curing agent 650.
In this example, 50g of e51 and H52-1 were respectively taken, and the corresponding polyamide 650 curing agent was weighed according to the method in claim 8, i.e., 50g of e51 epoxy resin was mixed with 47g of polyamide 650, and 50g of H52 modified epoxy resin was mixed with 32g of polyamide 650, and after mixing, the mixture was poured into a mold and cured at 50 ℃, and then sliced for data detection. Table 7 is a comparison of the two data before and after the epoxy resin modification.
TABLE 7
As is clear from Table 7, when caprolactone grafted on an epoxy resin exceeds the limit, the impact strength after curing is increased to 29.3KJ/m2, but the viscosity is greatly increased and the fluidity is also affected to a certain extent.
Preparation and performance of the solvent-free PET film coating:
adding 150g H52 into a four-neck flask provided with a stirring paddle, a thermometer and a condenser, dehydrating for 1h under vacuum at 80 ℃, then reducing the temperature to about 50 ℃, adding 30.69g of MDI, raising the temperature to 90 ℃ after the temperature is stabilized, reacting for 3h, adding 44g of 400 polycaprolactone polyol, continuing to react for 3h, and then cooling and taking out the product. The final epoxy equivalent weight tested was 425 and the designed epoxy equivalent weight was 427 at which time the polyol was fully grafted. Normally, the degree of aggregation is the same at both ends of 400 molecular weight polycaprolactone polyol, so X ═ Y ═ 1.35.
50g of polyurethane modified epoxy resin is taken, 10.2g of polyetheramine curing agent is added, the mixture is evenly mixed and then blade-coated on a PET film, and the mixture is cured for 15min at the temperature of 45 ℃. And adding 15.5g of polyetheramine curing agent into 50g E51, uniformly mixing, then blade-coating on a PET film, and curing for 15min at 45 ℃. And comparing the tensile strength, the wear resistance and the adhesive force of the two epoxy resins, and judging whether the two epoxy resins have the phenomenon of fogging or degumming after-15-80 ℃ cold-hot circulation for one week. Table 8 shows the comparison of the above data.
TABLE 8
As can be seen from table 8, when the content of caprolactone in the modified epoxy is increased to a certain limit, the tensile strength is not greatly changed compared with example 3, the tensile strength in example 3 is 47mpa, the tensile strength in this example is 47mpa, the abrasion resistance is not greatly changed compared with example 3, but the impact strength is still improved compared with example 3.
Example 5
The preparation method comprises the steps of filling 800g of epoxy resin E51 (containing 2mol of epoxy groups) into a 1L four-neck flask provided with a magneton, a thermometer and a vacuum receiving tube, heating to 70 ℃, dehydrating in vacuum with the vacuum degree of-90 KPa and the dehydration time of 2h, reducing the temperature to 50 ℃, adding 88g of epsilon-caprolactone, uniformly mixing, heating to 55 ℃, dehydrating for 3h under the same vacuum degree, adding 30ppm of dihydroxy butyl catalyst, replacing for three times by nitrogen, heating to 170 ℃, reacting for 6h at the temperature, sampling for 3h, measuring the viscosity, sampling for one hour, measuring the viscosity, and recording the data (the sampling is required to be conducted by introducing nitrogen so as to prevent oxygen from entering and yellowing during sampling). After 6h, the viscosity was 11000mpa.s and the caprolactone residue was 0.93%. The temperature is reduced to 140 ℃, and the mixture is kept for 2h under the vacuum degree of-99 KPa, the final viscosity is 11850mpa.s, and the epoxy equivalent is 210. The epoxy resin used in this example was CYD-128, the hydroxyl group content was 0.14mol, the hydroxyl group content was 0.05mol per 1 CYD-128 epoxy resin, so m was 2.8, the caprolactone content was 0.77mol, if all grafted, the epoxy equivalent was 210, and the hydroxyl group content of all grafted epoxy resins was 0.28mol, so n was 2.75.
And (3) performance measurement:
the advantages of the caprolactone-modified epoxy resin are judged by comparing the data of the resin before and after modification on viscosity, impact strength and the like through proportioning and curing with a polyamide curing agent 650 (the active hydrogen equivalent of the polyamide 650 curing agent is 185).
In this example, 50g of e51 and H52 were respectively taken, and the corresponding polyamide 650 curing agents were weighed according to the method in claim 8, i.e., 50g of e51 epoxy resin was mixed with 47g of polyamide 650, and 50g of H52 modified epoxy resin was mixed with 43g of polyamide 650, and after mixing, the mixture was poured into a mold and cured at 50 ℃, and then sliced for data detection. Table 9 shows a comparison of the two data before and after modification of the epoxy resin.
TABLE 9
As can be seen from Table 9, the caprolactone-modified epoxy resin has a low viscosity at normal temperature, and the impact strength after curing is greatly improved.
Preparation and performance of the solvent-free PET film coating:
adding 150g H52 into a four-neck flask provided with a stirring paddle, a thermometer and a condenser, dehydrating for 1h under vacuum at 70 ℃, then reducing the temperature to about 50 ℃, adding 13.84g of HDI, raising the temperature to 90 ℃ after the temperature is stabilized, adding 132g of 1000-molecular-weight polycaprolactone polyol after reacting for 3h, continuing to react for 3h, and then reducing the temperature and taking out the product. The final epoxy equivalent weight tested was 414, and the designed epoxy equivalent weight was 414, at which time the polyol was fully grafted. Normally, the degree of aggregation is the same at both ends of 1000 molecular weight polycaprolactone polyol, so X ═ Y ═ 3.9.
Taking 50g of polyurethane modified epoxy resin, adding 7.2g of polyetheramine curing agent according to the calculation method in claim 8, uniformly mixing, blade-coating on a PET film, and curing for 15min at 45 ℃. And adding 15.5g of polyetheramine curing agent into 50g of E51, uniformly mixing, blade-coating on a PET film, and curing for 15min at 45 ℃. And comparing the tensile strength, the wear resistance and the adhesive force of the two epoxy resins, and judging whether the two epoxy resins have the phenomenon of fogging or degumming after-15-80 ℃ cold-hot circulation for one week. Table 10 shows the comparison of the above data.
Watch 10
As can be seen from Table 10, the overall performance of the polyurethane-modified H52 is greatly improved, and the tensile strength of H52 is 39mpa, which is far beyond that of the polyurethane-modified H52Tensile strength of conventional E51. Good adhesive force, no degumming and fogging phenomenon after one week of cold-hot cycle experiment, and the impact strength of 30.3KJ/m2The lifting effect is obvious compared with E51.
Example 6
The method comprises the steps of filling 600g of epoxy resin E51 (containing 2mol of epoxy groups) into a 1L four-neck flask provided with a magneton, a thermometer and a vacuum receiving tube, heating to 70 ℃, dehydrating in vacuum with the vacuum degree of-90 KPa and the dehydration time of 2h, reducing the temperature to 50 ℃, adding 200g of epsilon-caprolactone, uniformly mixing, heating to 55 ℃, dehydrating for 3h under the same vacuum degree, adding 100ppm of dihydroxy butyl catalyst, replacing for three times by nitrogen, heating to 180 ℃, reacting for 5h at the temperature, sampling for 3h after reaction, measuring the viscosity, sampling for one time every hour, and recording data (wherein nitrogen is required to be introduced during sampling, and oxygen is prevented from entering to cause yellowing during sampling). After 6h the viscosity was 11000mpa.s and the caprolactone residue was 0.88%. The temperature is reduced to 140 ℃, and the mixture is kept for 2h under the vacuum degree of-99 KPa, the final viscosity is 12080mpa.s, and the epoxy equivalent is 253. The epoxy resin used in this example was CYD-128, the hydroxyl group content was 0.14mol, the hydroxyl group content was 0.05mol per 1 CYD-128 epoxy resin, so m was 2.8, the caprolactone content was 1.74mol, the epoxy equivalent was 254 if all grafted, and the hydroxyl group content was 0.28mol after all grafted, so n was 6.2.
And (3) performance measurement:
the advantages of the caprolactone-modified epoxy resin are judged by comparing the data of the resin before and after modification on viscosity, impact strength and the like through proportioning and curing with a polyamide curing agent 650 (the active hydrogen equivalent of the polyamide 650 curing agent is 185).
In this example, 50g of E51 and H52 were taken, and the corresponding curing agents for polyamide 650, namely 50g of E51 epoxy resin was mixed with 47g of polyamide 650, and 50g of H52 modified epoxy resin was mixed with 36.5g of polyamide 650, and after mixing, the mixture was poured into a mold and cured at 50 ℃ and sliced for data detection, were weighed according to the method of claim 8. Table 11 shows a comparison of the two data before and after modification of the epoxy resin.
TABLE 11
As can be seen from table 11, the caprolactone-modified epoxy resin has a lower viscosity at normal temperature, and the impact strength after curing is greatly improved.
Preparation and performance of the solvent-free PET film coating:
adding 150g H52 into a four-neck flask provided with a stirring paddle, a thermometer and a condenser, dehydrating for 1h under vacuum at 70 ℃, then reducing the temperature to about 50 ℃, adding 29g of HDI, raising the temperature to 90 ℃ after the temperature is stabilized, adding 121g of 1000-molecular-weight polycaprolactone polyol after reacting for 3h, continuing to react for 3h, and then reducing the temperature and taking out the product. The final epoxy equivalent weight tested was 504 and the designed epoxy equivalent weight was 506 when the polyol was fully grafted. Normally, the degree of aggregation is the same at both ends of 1000 molecular weight polycaprolactone polyol, so X ═ Y ═ 3.9.
Taking 50g of polyurethane modified epoxy resin, adding 6g of polyetheramine curing agent according to the calculation method in claim 8, uniformly mixing, blade-coating on a PET film, and curing for 15min at 45 ℃. And adding 15.5g of polyetheramine curing agent into 50g of E51, uniformly mixing, blade-coating on a PET film, and curing for 15min at 45 ℃. And comparing the tensile strength, the wear resistance and the adhesive force of the two epoxy resins, and judging whether the two epoxy resins have the phenomenon of fogging or degumming after-15-80 ℃ cold-hot circulation for one week. Table 12 shows the comparison of the above data.
TABLE 12
From table 12, it can be seen that the overall performance of the polyurethane-modified H52 is greatly improved, and the tensile strength of H52 is 38mpa, which is far higher than that of conventional E51. Good adhesive force, no degumming and fogging phenomenon after one week of cold-hot cycle experiment, and the impact strength of the paint is 32.4KJ/m2The lifting effect is obvious compared with E51.
Example 7
The method comprises the steps of filling 600g of epoxy resin E51 (containing 2mol of epoxy groups) into a 1L four-neck flask provided with a magneton, a thermometer and a vacuum receiving tube, heating to 80 ℃ and dehydrating in vacuum with the vacuum degree of-99 KPa and the dehydration time of 2h, reducing the temperature to 50 ℃, adding 300g of epsilon-caprolactone, uniformly mixing, heating to 55 ℃, dehydrating for 3h under the same vacuum degree, adding 60ppm of dihydroxy butyl tin chloride catalyst, replacing for three times by nitrogen, heating to 140 ℃, reacting for 6h at the temperature, sampling for 3h, measuring the viscosity, sampling for one time every hour, and recording data (taking care that nitrogen is always introduced when sampling to prevent oxygen from yellowing during sampling). After 6h the viscosity was 11460mpa.s with 0.98% caprolactone residue. The temperature is reduced to 140 ℃, and the mixture is maintained for 2 hours under the vacuum degree of-99 KPa, the final viscosity is 12240mpa.s, and the epoxy equivalent is 283. The epoxy resin used in this example was CYD-128, the hydroxyl group content was 0.14mol, the hydroxyl group content was 0.05mol per 1 CYD-128 epoxy resin, so m was 2.8, the caprolactone content was 2.63mol, the epoxy equivalent was 285 if all grafted, and the hydroxyl group content was 0.28mol after all grafted, so n was 9.3.
And (3) performance measurement:
the advantages of the caprolactone modified epoxy resin are judged by comparing the data of the resin before and after modification in the aspects of viscosity, impact strength and the like through proportioning and curing with the polyamide curing agent 650.
In this example, 50g of E51 and H52 were respectively taken, and the corresponding curing agents of polyamide 650, namely 50g of E51 epoxy resin was mixed with 47g of polyamide 650, and 50g of H52 modified epoxy resin was mixed with 32.6g of polyamide 650, and after mixing, the mixture was poured into a mold to cure at 50 ℃ and then sliced for data detection, were weighed according to the method of claim 8. Table 3 is a comparison of the two data before and after the epoxy resin modification.
Watch 13
As can be seen from table 13, the caprolactone-modified epoxy resin had an increased viscosity at room temperature but had no influence on the flowability, and the impact strength after curing was greatly improved.
Preparation and performance of the solvent-free PET film coating:
adding 150g H52 into a four-neck flask provided with a stirring paddle, a thermometer and a condenser, dehydrating for 1h under vacuum at 75 ℃, then reducing the temperature to about 50 ℃, adding 43.1g of MDI, raising the temperature to 90 ℃ after the temperature is stable, adding 42g of 400-molecular-weight polycaprolactone polyol after reacting for 3h, continuing to react for 3h, and reducing the temperature and taking out the product. The final epoxy equivalent weight tested was 443, the design epoxy equivalent weight was 443, at which time the polyol was fully grafted. Normally, the degree of aggregation is the same at both ends of 400 molecular weight polycaprolactone polyol, so X ═ Y ═ 1.35.
50g of polyurethane modified epoxy resin is taken, 6.8g of polyetheramine curing agent is added, the mixture is evenly mixed and then blade-coated on a PET film, and the mixture is cured for 15min at the temperature of 45 ℃. And adding 15.5g of polyetheramine curing agent into 50g of E51, uniformly mixing, blade-coating on a PET film, and curing for 15min at 45 ℃. And comparing the tensile strength, the wear resistance and the adhesive force of the two epoxy resins, and judging whether the two epoxy resins have the phenomenon of fogging or degumming after-15-80 ℃ cold-hot circulation for one week. Table 14 shows the comparison of the above data.
TABLE 14
As can be seen from Table 14, the overall performance of the polyurethane-modified H52 is greatly improved, and the tensile strength of H52-2 is 43mpa, which is far higher than that of conventional E51. Good adhesive force, no degumming and fogging phenomenon after one week of cold-hot cycle experiment, and the impact strength of the paint is 32KJ/m2The lifting effect is obvious compared with E51.
The principle of the invention is as follows:
firstly, aiming at the problem that the viscosity of common epoxy resin is higher at normal temperature, the aliphatic long-chain section epsilon-caprolactone is grafted on the secondary hydroxyl of the bisphenol A epoxy resin, so that the originally linear molecular structure is changed into a branched structure, the winding of intermolecular chain ends can be effectively reduced, the effect of reducing the viscosity is achieved, and the conjugation between large pi bonds among benzene ring structures of the bisphenol A epoxy resin can be effectively reduced by introducing the branched aliphatic long chain into the position, so that the viscosity of a system is reduced, and the modified epoxy resin has better fluidity at normal temperature.
The reasons for higher hardness, poor impact resistance and poor toughness of the pure bisphenol A epoxy resin after curing are derived from a rigid benzene ring structure existing in a molecular chain segment of the resin and the conjugation of a large pi bond existing between two benzene rings, so that the bisphenol A epoxy resin has the problems of high hardness and high brittleness after curing. According to the invention, the soft long aliphatic chain segment is introduced on the secondary hydroxyl of the bisphenol A epoxy resin, so that the proportion of a rigid structure in the whole molecular chain segment is reduced, the conjugation of a large pi bond between two benzene rings is weakened, the steric hindrance is reduced, and the cured epoxy resin has better toughness.
In the application method of the epsilon-caprolactone modified epoxy resin on the PET film, the proportion of the curing agent of the epoxy resin to the epoxy resin is that if the amine curing agent depends on the active hydrogen equivalent of the amine curing agent, 1mol of active hydrogen can react with 1mol of epoxy group, for example, the active hydrogen equivalent of the polyether amine curing agent is 61, the epoxy value of the epoxy resin is 0.51, and the epoxy resin is represented by the formula:
the total amount of polyetheramine curing agent required for 100G of epoxy resin is 31.11G, and if the epoxy value of epoxy resin is 0.35, the total amount of polyetheramine curing agent required for 100G of epoxy resin is 21.35G, so that the amount of curing agent required for the epoxy resin with different epoxy values is different from that required for the epoxy resin with different epoxy values to be completely cured. Normally, the actual addition amount of the curing agent is slightly higher than the theoretical value, so as to prevent the loss of the curing agent in the curing process, so that the whole epoxy is not completely cured and cannot meet the use requirement.
The invention relates to the application of the modified epoxy resin on a solvent-free PET film coating. The Polyurethane (PU) is a high polymer material which is generated by the reaction of isocyanate and polycaprolactone polyol and contains a flexible chain segment and a carbamate group in a molecular chain, has good toughness and wear resistance, can be used as a modified toughening agent and added into EP, and can greatly improve the toughness and wear resistance of epoxy resin after being cured. The epoxy resin modified by caprolactone converts secondary hydroxyl on the original chain segment into primary hydroxyl on the branched chain, and the reactivity of the primary hydroxyl and isocyanate in the field of polyurethane is far higher than that of the secondary hydroxyl and isocyanate, so that the epoxy resin modified by caprolactone can react with isocyanate quickly, and the production efficiency is improved.
The polycaprolactone polyol is used because the polycaprolactone polyol has good flexibility and low-temperature resistance, the two ends of the polycaprolactone polyol are reactive hydroxyl groups, the polycaprolactone polyol has very good reactivity, and the molecular weight of the polycaprolactone polyol used in the embodiment is 400 and 1000, so that the polycaprolactone polyol can meet any requirements of chain extension or end capping.
In the preparation and performance measurement of the solvent-free PET film coating in the examples, the amount of all the curing agents used for the epoxy resin is the amount that the epoxy resin is completely cured, the controlled variable is that the epoxy resin is completely cured, if the amounts of the curing agents are the same, the curing of E51 cannot be completed, and the isocyanate-modified epoxy resin is completely cured, and the test effect cannot be achieved, so that the experimental data are wrong.
The epoxy resin modified by polyurethane is used as a solvent-free coating, so that the emission of Volatile Organic Compounds (VOC) can be greatly reduced during curing, and the hardness, scratch resistance, impact strength, high temperature and high humidity resistance of the curing coating are obviously improved compared with those of the common solvent-based coating.
The application field of the invention is not limited to the coating of the PET packaging film industry, such as the adhesive used when the sole and the vamp of the leather industry are bonded, but also the bonding between the alloy and the alloy, because the coating has better fluidity and infiltration capacity before curing, can permeate into each tiny space of the rough surface of the leather and the gap of the alloy, and utilizes polyurethane to modify the epoxy resin, thereby improving the shortages of brittleness and insufficient stretching of the epoxy resin, simultaneously leading the composition structure of the polymer to have active functional groups such as hydroxyl, epoxy group and the like, leading the substance to realize chemical bond anchoring to the substrate more easily, and simultaneously leading the aging resistance, bending resistance, moisture resistance and high temperature resistance of the adhesive layer to be stronger.
While embodiments of the invention have been disclosed above, it is not limited to the applications set forth in the description and embodiments, which are fully applicable to various fields of endeavor for which the invention is intended, and further modifications may readily be effected therein by those skilled in the art, without departing from the general concept defined by the claims and their equivalents, which are to be limited not to the specific details shown and described herein.