Application of DOPO in anti-yellowing of unsaturated polyester resin and anti-yellowing unsaturated polyester resin composition

Abstract

The invention belongs to the technical field of high polymer materials, and relates to application of DOPO (9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) in yellowing resistance of unsaturated polyester resin and an anti-yellowing unsaturated polyester resin composition. A small amount of DOPO is introduced into an unsaturated polyester resin system, so that the anti-yellowing performance of a solid product formed after the unsaturated polyester resin system is cured can be improved. And the gelation time of the unsaturated polyester resin is not influenced under the condition that a small amount of the unsaturated polyester resin is added. In addition, the gelation time of the unsaturated polyester resin containing DOPO is stable along with the storage time and does not drift.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high polymer materials, and relates to application of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) in anti-yellowing of unsaturated polyester resin and anti-yellowing unsaturated polyester resin composition. BACKGROUND

[0002] Unsaturated polyester is a linear high molecular compound with ester bond and unsaturated C=C double bond, which is obtained by condensation of unsaturated dibasic acid and dibasic alcohol. After mixing with diluent such as vinyl monomer, unsaturated polyester resin is obtained. Unsaturated polyester resin can be cured at room temperature or under heating condition using curing agent to form three-dimensional cross-linked solid material. Its operation process is simple, and it has good performance, and is widely used in the manufacture of glass steel, artificial stone, paint, button, etc.

[0003] The solid product obtained after curing of unsaturated polyester resin will gradually age and yellow under the action of light, heat and oxygen. In order to alleviate this problem, the industry usually adds antioxidants to the resin system. Common antioxidants include hindered phenol, phosphite, thio and their compounds, etc. These antioxidants can delay the yellowing process to a certain extent by inhibiting oxidation reaction. However, since the curing process of unsaturated polyester resin is essentially a free radical polymerization reaction through free radicals generated by curing agent, the addition of antioxidants in the resin will cause the curing speed to decrease due to the reaction of antioxidants and free radicals, incomplete curing, and reduction of the anti-yellowing performance of antioxidants, etc.

[0004] Wang Guozhong et al. (Thermosetting Resin, 2012, V27(2), 25-27) preferred phosphite antioxidant 3010 for anti-yellowing of unsaturated polyester resin. However, the experimental results showed that antioxidant 3010 needs 0.45% mass fraction to significantly improve the heat and oxygen aging resistance of the resin. In addition, it is found in practical application that after adding this kind of antioxidant, the gel time of the resin is easy to drift with storage time, affecting the processing stability.

[0005] Therefore, so far, the industry has been looking for an additive with small amount, little effect on the curing process of unsaturated polyester resin during curing, and excellent anti-yellowing performance after curing. SUMMARY

[0006] To solve the above technical problems, the present application provides DOPO as an anti-yellowing aid for unsaturated polyester resin. The compound has the characteristics of small dosage, small influence on the curing process of unsaturated polyester, small gel time drift, excellent anti-yellowing performance, etc. The present application adopts the following technical solutions to achieve the purpose of the application: one aspect of the present application provides the application of DOPO in the anti-yellowing of unsaturated polyester resin. The introduction of DOPO into the unsaturated polyester resin system can improve the anti-yellowing performance of the solid product formed after the curing of the unsaturated polyester resin system.

[0007] The unsaturated polyester resin system includes unsaturated polyester resin, which is mixed from unsaturated polyester prepolymer and vinyl monomer. The unsaturated polyester resin system also includes curing agent and accelerator. The unsaturated polyester resin system also includes other aids, including antioxidants, stabilizers, coloring aids (such as pigments, dyes, color paste, pearl paste, etc.), processing aids (such as dispersants, release agents, etc.), wax water, fillers, etc.

[0008] Preferably, the yellow index of the solid product formed after the curing of the unsaturated polyester resin system containing DOPO is significantly less than the yellow index of the solid product formed after the curing of the unsaturated polyester resin system without DOPO after heat treatment at 150℃ for 30min, according to the standard HG / T 3862-2006.

[0009] The difference between the unsaturated polyester resin system containing DOPO and the unsaturated polyester resin system without DOPO is only that the former contains DOPO and the latter does not contain DOPO, and the other ingredients remain the same.

[0010] Preferably, the difference between the yellow index of the solid product formed after the curing of the unsaturated polyester resin system containing DOPO and the yellow index of the solid product formed after the curing of the unsaturated polyester resin system without DOPO after heat treatment at 150℃ for 30min is ≥2.

[0011] The solid product formed after the curing of the unsaturated polyester resin system containing DOPO in this paper is prepared by mixing the ingredients in the unsaturated polyester resin system containing DOPO except for the curing agent, then adding the curing agent, stirring uniformly, and then pouring into a mold to obtain the solid product. The temperature and time control of the curing process need to be adjusted flexibly according to the resin formula, product thickness and performance requirements. Similarly, the solid product formed after the curing of the unsaturated polyester resin system without DOPO is prepared by mixing the ingredients in the unsaturated polyester resin system without DOPO except for the curing agent, then adding the curing agent, stirring uniformly, and then pouring into a mold to obtain the solid product.

[0012] The second aspect of the present invention provides an anti-yellowing unsaturated polyester resin composition, comprising:

[0013] 100 parts by weight of unsaturated polyester resin;

[0014] 0.01 to 3 parts by weight of DOPO.

[0015] The unsaturated polyester resin is a mixture of unsaturated polyester prepolymer and vinyl monomer. The unsaturated polyester prepolymer is a linear high molecular compound with ester bond and unsaturated C=C double bond, which is prepared by condensation polymerization of raw materials including unsaturated diacid or anhydride and dihydric alcohol. The C=C double bond from unsaturated diacid or anhydride in the main chain can undergo free radical copolymerization with vinyl monomer.

[0016] Common unsaturated diacids or anhydrides include one or more of maleic anhydride, maleic acid, fumaric acid, itaconic acid, etc. Common dihydric alcohols include one or more of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, etc.

[0017] The raw materials for preparing the unsaturated polyester prepolymer can also include saturated diacids or anhydrides. Common saturated diacids or anhydrides include one or more of succinic acid, adipic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, isophthalic anhydride, etc.

[0018] The vinyl monomer is an olefinically unsaturated compound containing vinyl group (CH2=CH-) and / or in the molecular structure. According to the type of substituent, it can be divided into styrene or its derivatives (such as styrene, α-methylstyrene, p-methylstyrene, o-methylstyrene, p-tert-butylstyrene), (meth) acrylate (such as methyl methacrylate, methyl acrylate, ethyl acrylate, butyl methacrylate), halogenated ethylene (such as vinyl chloride, vinylidene chloride), alkyl-substituted olefins (such as propylene, 1-butene, isoprene), etc.

[0019] The vinyl monomer can be divided into monofunctional monomer and multifunctional monomer according to function. The monofunctional monomer contains a single polymerizable double bond, including styrene, α-methylstyrene, p-methylstyrene, o-methylstyrene, acrylate, methacrylic acid, methacrylate, etc. The multifunctional monomer contains 2 or more reactive C=C double bonds, including divinylbenzene, diethylene glycol bisacrylate, ethylene glycol bismethacrylate, etc. Alternatively, the vinyl monomer is styrene, styrene derivative, (meth) acrylate or a mixture thereof.

[0020] Optionally, the vinyl monomer is styrene or a derivative thereof.

[0021] Optionally, the vinyl monomer is a mixture of styrene and methyl methacrylate (MMA).

[0022] Preferably, the vinyl monomer is styrene.

[0023] Optionally, the unsaturated polyester resin comprises one or more of ortho-phenol type unsaturated polyester resin, meta-phenol type unsaturated polyester resin, para-phenol type unsaturated polyester resin, bisphenol A type unsaturated polyester resin, vinyl type unsaturated polyester resin, and halogenated unsaturated polyester resin, etc.

[0024] Preferably, the unsaturated polyester resin is meta-phenol type unsaturated polyester resin.

[0025] The amount of DOPO is 0.01-3 parts by weight per 100 parts by weight of the unsaturated polyester resin. If the amount of DOPO is too low, the anti-yellowing property is reduced; if the amount of DOPO is higher than 3 parts by weight, the initial color of the unsaturated polyester resin becomes darker, and the gel time is prolonged, and the economy is reduced.

[0026] Optionally, the amount of DOPO can be any value in 0.010, 0.015, 0.020, 0.030, 0.040, 0.050, 0.060, 0.070, 0.080, 0.090, 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0 parts by weight per 100 parts by weight of the unsaturated polyester resin, or a range value between any two thereof.

[0027] Preferably, the amount of DOPO is 0.01-1 parts by weight per 100 parts by weight of the unsaturated polyester resin. More preferably, the amount of DOPO is 0.03-0.20 parts by weight per 100 parts by weight of the unsaturated polyester resin.

[0028] The present application has found that when the amount of DOPO in the unsaturated polyester resin is low, the yellow index of the solid product formed by curing the unsaturated polyester resin system containing DOPO before high temperature treatment is close to that of the solid product formed by curing the unsaturated polyester resin system without DOPO, but after high temperature treatment, the yellow index of the former is significantly lower than that of the latter. Moreover, more surprisingly, the low addition amount of DOPO within the concentration range for anti-yellowing does not cause a large change in the gel time of the unsaturated polyester resin system, and the gel time does not drift with storage time.

[0029] When the amount of DOPO is high, although the yellow index of the solid product formed by curing the unsaturated polyester resin system containing DOPO before high temperature treatment is greater than that of the solid product formed by curing the unsaturated polyester resin system without DOPO before high temperature treatment, it is very unexpected that the yellow index of the solid product formed by curing the unsaturated polyester resin system containing high content of DOPO after high temperature treatment is not only lower than that of the solid product formed by curing the unsaturated polyester resin system without DOPO after high temperature treatment, but also lower than its own yellow index before high temperature treatment. The higher the content of DOPO, the greater the decrease in the yellow index, and even the yellow index approaches 0 (close to colorless).

[0030] Preferably, the anti-yellowing unsaturated polyester resin composition further comprises a curing agent and an accelerator.

[0031] Optionally, the curing agent is a peroxide compound. The optional peroxide compound includes, but is not limited to, one or more of methyl ethyl ketone peroxide, cyclohexanone peroxide, methyl isobutyl ketone peroxide, benzoyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, 2,4-dichlorobenzoyl peroxide, dodecanoyl peroxide, etc. Preferably, the curing agent is methyl ethyl ketone peroxide.

[0032] Optionally, the amount of the curing agent is 0.001-2 parts by weight per 100 parts by weight of the unsaturated polyester resin. Too low amount of the curing agent results in incomplete curing. Higher amount than 2 parts by weight results in too fast curing speed and short operation time.

[0033] The accelerator is any compound that can accelerate the decomposition of the curing agent at a lower temperature to generate free radicals, thereby accelerating the crosslinking reaction of the unsaturated polyester prepolymer and the vinyl monomer.

[0034] Optionally, the accelerator of the present application is one or more of cobalt organic salts, tertiary amines. The cobalt organic salts include one or more of cobalt iso-octoate, cobalt naphthenate, cobalt naphthenate, cobalt neodecanoate, etc. The tertiary amines include one or more of N,N-dimethyl aniline, N,N-diethyl aniline, N-methyl-N-2-hydroxyethyl-p-toluidine, dimethyl benzyl amine, triethylene diamine, etc.

[0035] Optionally, the amount of the accelerator is 0.001-2 parts by weight per 100 parts by weight of the unsaturated polyester resin.

[0036] Preferably, the curing agent is methyl ethyl ketone peroxide or cyclohexanone peroxide, and the accelerator is a cobalt organic salt.

[0037] Further preferably, the curing agent is methyl ethyl ketone peroxide, and the accelerator is cobalt isooctoate.

[0038] Optionally, the anti-yellowing unsaturated polyester resin composition further comprises other auxiliary agents, including antioxidants, stabilizers, coloring auxiliary agents (such as pigments, dyes, color paste, pearlescent paste, etc.), processing auxiliary agents (such as dispersants, release agents, etc.), wax water, fillers, etc. Other auxiliary agents are added according to actual needs to achieve the application purpose.

[0039] Compared with the prior art, the present application has the following beneficial effects:

[0040] 1. The introduction of DOPO into the unsaturated polyester resin system can improve the anti-yellowing property of the unsaturated polyester resin system, and a small amount can greatly inhibit the thermal oxidative yellowing of the unsaturated polyester resin.

[0041] 2. When the addition amount of DOPO is high (≥0.6 parts by weight per 100 parts by weight of the unsaturated polyester resin), the yellow index of the solid product formed after curing of the unsaturated polyester resin system is greatly reduced after high-temperature treatment, and the higher the content of DOPO, the greater the decrease in the yellow index, and even the yellow index is close to 0, and the sample is close to colorless.

[0042] 3. The introduction of DOPO into the unsaturated polyester resin system does not affect the gel time of the unsaturated polyester resin in a small amount.

[0043] 4. The introduction of DOPO into the unsaturated polyester resin system stabilizes the gel time of the unsaturated polyester resin with storage time, and the gel time does not drift.

[0044] 5. The addition of DOPO in the unsaturated polyester resin in which the vinyl monomer is styrene and methyl methacrylate also has outstanding anti-yellowing effect.

[0045] 6. The present application preferably uses meta-benzene type unsaturated polyester resin as the base resin; in the meta-benzene type unsaturated polyester resin system, the addition of DOPO not only has less effect on the gel time, but also can give the resin more outstanding anti-yellowing effect. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1The yellow index of the solid product cured from the unsaturated polyester resin composition of Comparative Examples 1-3 and Examples 1-8 before and after high temperature treatment was compared. DETAILED DESCRIPTION

[0047] In the description of the present application, unless otherwise specified, the numerical range "a~b" represents a shorthand notation for any real combination between a and b, and includes a and b. Various numbers include two, three, four, five, and more.

[0048] The technical solutions of the present application are further described and illustrated below by specific examples and drawings. It should be understood that the specific examples described herein are only used to help understand the present application, and are not used to limit the specific application. The drawings used herein are only used to better illustrate the disclosed content of the present application, and do not limit the scope of protection. If not otherwise specified, the raw materials used in the examples of the present application are all commonly used raw materials in the art, and the methods used in the examples are all conventional methods in the art.

[0049] The following are the sources of raw materials:

[0050] Unsaturated polyester resin 1: Tianhe TH-926 (m-phenyl type unsaturated polyester resin containing 30% by weight of styrene).

[0051] Unsaturated polyester resin 2: Tianhe TH-196 (o-phenyl type unsaturated polyester resin containing 30% by weight of styrene).

[0052] Cobalt accelerator: Tianhe TZ-10 cobalt water.

[0053] Methyl ethyl ketone peroxide (MEKP): Nolane M-50.

[0054] 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO): Shanghai Aladdin Biochemical Technology Co., Ltd.

[0055] Antioxidant 3010: Wuhan Kemik Biological Medicine Technology Co., Ltd.

[0056] Methyl methacrylate (MMA): National Pharmaceutical Group Chemical Reagent Co., Ltd.

[0057] Comparative Examples 1-9 and Examples 1-14:

[0058] The ingredients and weight parts of the unsaturated polyester resin composition of Comparative Examples 1-9 and Examples 1-14 are shown in Table 1.

[0059] Yellow index (YI) determination:

[0060] The ingredients of the unsaturated polyester resin compositions of Comparative Examples 1-9 and Examples 1-14 except the curing agent were added into a beaker, stirred well, then the curing agent MEKP was added, and stirred until uniform, poured into a mold, cured to a certain hardness to obtain a sample with a thickness of 5 mm, then further cured at 80°C for 40 min, at this time the sample was taken out, and the yellow index was determined according to the standard of HG / T 3862-2006 "Plastics Yellow Index Test Method" using a Lambda 950 type ultraviolet visible near infrared spectrophotometer, marked as YI before high temperature baking; then the sample after curing was baked in a constant temperature air oven at 150°C, the sample was taken out every 30 min to test the yellow index, a total of 90 min, to obtain the yellow index after baking at 150°C for 30 min, the yellow index after baking for 60 min, and the yellow index after baking for 90 min, as shown in Table 1 and Figure 1

[0061] Gel time: according to the gel time determination method in the standard GB / T 7193-2008 "Unsaturated Polyester Resin Test Method": the ingredients of the unsaturated polyester resin compositions of Comparative Examples 1-9 and Examples 1-14 except the accelerator were weighed into a beaker, heated in a constant temperature water bath and stirred well, when the temperature of the mixture reached 25°C, the accelerator was added, immediately start the stopwatch when the last drop was added, and stir the mixture. Observe every 30 seconds, test the flow of the mixture with a glass rod, until the stringing state appears, stop the stopwatch, and record the time shown by the stopwatch, which is the gel time. The gel time of the unsaturated polyester resins of Comparative Examples 1-9 and Examples 1-14 is shown in Table 1.

[0062] Table 1 Gel time and yellow index of unsaturated polyester resins of Comparative Examples 1-9 and Examples 1-14

[0063]

[0064] Comparisons of Examples 1-2 and Comparative Example 1 show that the gel time of the unsaturated polyester resin with 0.05-0.10 parts by weight of DOPO added is very close to the gel time of the unsaturated polyester resin without DOPO (Comparative Example 1). The color of the solid product formed after curing of Examples 1-2 is similar to that of Comparative Example 1 before high temperature treatment, but the anti-yellowing performance of the solid product formed after curing of the unsaturated polyester resin containing DOPO is significantly stronger than that of the blank sample without DOPO after high temperature heat treatment.

[0065] ​Comparative Examples 2-3 show that the solid state articles formed from the unsaturated polyester resins with 0.05-0.20 parts by weight of DOPO added have not only lower yellowness index before high temperature treatment, but also much lower yellowness index after high temperature treatment than the solid state articles formed from the unsaturated polyester resins with 0.30-0.45 parts by weight of antioxidant 3010 added, which indicates that DOPO provides better anti-yellowing performance than antioxidant 3010 at lower addition level.

[0066] Comparative Example 2 and Examples 4-8 show that when the amount of DOPO is increased, the solid state articles formed from the unsaturated polyester resins have higher yellowness index before high temperature treatment than the solid state articles formed from the unsaturated polyester resins with antioxidant 3010, but the former has much lower yellowness index after high temperature treatment than the latter. Especially for Examples 6-8, the samples are almost colorless after 30 minutes of heat treatment, which has very strong high temperature anti-yellowing performance.

[0067] Comparing Comparative Examples 5-6 and Comparative Example 4, it can be seen that the solid state articles formed from the unsaturated polyester resins with MMA diluent and antioxidant 3010 added have similar yellowness index before and after high temperature treatment as the solid state articles formed from the unsaturated polyester resins without antioxidant 3010 (Comparative Example 4), which indicates that antioxidant 3010 has no anti-yellowing effect in the unsaturated polyester resins with MMA diluent.

[0068] Comparing Comparative Example 4 and Examples 9-10, it can be seen that the solid state articles formed from the unsaturated polyester resins with MMA diluent and DOPO added have similar yellowness index before high temperature treatment as the solid state articles formed from the unsaturated polyester resins without DOPO (Comparative Example 4), but the former has much lower yellowness index after high temperature treatment than the latter, which indicates that DOPO has excellent anti-yellowing effect in the unsaturated polyester resins with MMA diluent.

[0069] Comparing Examples 2 and 9, and Examples 3 and 10, it can be seen that adding DOPO in the unsaturated polyester resins with MMA diluent has more prominent anti-yellowing effect than adding DOPO in the unsaturated polyester resins without MMA diluent.

[0070] Comparative Example 7 and Examples 11-14 show that DOPO also has obvious high temperature anti-yellowing effect in the ortho-phthalate type unsaturated polyester resins.

[0071] Comparative Examples 8-9 and Examples 13-14 show that, in the ortho-phenyl type unsaturated polyester resin system, although the cured product of the unsaturated polyester resin containing DOPO has a higher yellow index than the cured product of the unsaturated polyester resin containing antioxidant 3010 before high temperature treatment, the former has a significantly lower yellow index than the latter after high temperature treatment. For example, the cured product of the unsaturated polyester resin containing 0.30 parts by weight of DOPO has a significantly lower yellow index after high temperature treatment than the cured product of the unsaturated polyester resin containing 0.45 parts by weight of antioxidant 3010 after the same high temperature treatment, indicating that DOPO has a better anti-yellowing effect on the ortho-phenyl type unsaturated polyester resin.

[0072] In addition, by comparing the results of Examples 1-8 and Examples 11-14, it can be seen that, in the meta-phenyl type unsaturated polyester resin system, the addition of DOPO has a smaller effect on the gel time and the resin has a lower yellowing index after heat treatment than in the ortho-phenyl type unsaturated polyester resin system.

[0073] Comparative Examples 10-11 and Examples 15-20:

[0074] The components and parts by weight of the unsaturated polyester resin compositions of Comparative Examples 10-11 and Examples 15-20 are shown in Table 2.

[0075] Yellow index (YI) determination and calculation of yellow index change ΔYI:

[0076] The components of Comparative Examples 10-11 and Examples 15-20, except for the curing agent, were added to a beaker and stirred thoroughly, then the curing agent MEKP was added and stirred until uniform, poured into a mold, and cured to a certain hardness to obtain a sample with a thickness of 5 mm, then the sample was taken out and further cured at 80°C for 40 min. The yellow index was determined according to the standard of HG / T 3862-2006 "Plastic Yellow Index Test Method" using a Lambda 950 ultraviolet-visible near-infrared spectrophotometer. Then the cured sample was baked in a constant temperature air oven at 150°C, and the yellow index was tested every 30 min and the yellow index change was calculated. The baking time was 90 min, and the yellow index change after baking for 30 min, 60 min, and 90 min was obtained. The yellow index change ΔYI was calculated as follows:

[0077] ΔYI = YI - YI0

[0078] In the formula, YI is the yellow index of the sample after high temperature baking, and YI0 is the yellow index of the sample before high temperature baking.

[0079] The results are shown in Table 2.

[0080] Gel time determination is the same as above. The results are shown in Table 2.

[0081] Table 2 Gel time and yellow index change of Comparative Examples 10-11 and Examples 15-20

[0082]

[0083] As can be seen from Table 2, the solid product formed after curing of the unsaturated polyester resin without adding antioxidant 3010 or DOPO (Comparative Example 10) has a positive ΔYI value and the value increases significantly as the high-temperature baking time increases, indicating that the yellow index increases and the yellow color becomes darker and darker. The ΔYI value of the product with the addition of antioxidant 3010 (Comparative Example 11) is smaller than that of the former, and the increase is smaller, indicating that antioxidant 3010 has a certain anti-yellowing effect. The ΔYI of the product with the addition of DOPO (Examples 15-20) is close to 0 or negative, indicating that the anti-yellowing effect is very significant. The product of Example 15 is observed by naked eye to have almost no color change before and after high-temperature treatment, and has excellent anti-yellowing performance, and the gel time is close to that of the unsaturated polyester resin without the addition of DOPO (Comparative Example 10). After 90 min of high-temperature treatment, the product with the addition of 0.45% of DOPO (Example 16) has no yellowing, while the product with the addition of 0.45% of antioxidant 3010 (Comparative Example 11) has very obvious yellowing after high-temperature treatment. Examples 17-20 show that increasing the addition amount of DOPO increases the anti-yellowing performance of the sample, and the sample has no yellow color after high-temperature treatment, and the color is stable and basically unchanged as the baking time increases; and the gel time is close to that of the unsaturated polyester resin without the addition of DOPO.

[0084] Comparative Examples 12-13 and Examples 21-27

[0085] The unsaturated polyester resin and DOPO are mixed uniformly at a ratio of 100 parts by weight of unsaturated polyester resin and 0.5 parts by weight of DOPO and placed in the room. On the 1st day (Example 21), the 10th day (Example 22), the 20th day (Example 23), the 30th day (Example 24), the 40th day (Example 25), the 50th day (Example 26), and the 60th day (Example 27), samples are taken and the gel time is tested according to the method in the standard GB / T 7193-2008 "Test Methods for Unsaturated Polyester Resin" above (the amounts of the accelerant and the curing agent are both: 100 parts by weight of unsaturated polyester resin plus 0.5 parts by weight of accelerant and 0.5 parts by weight of curing agent).

[0086] Unsaturated polyester resin 100 parts by weight and diphenyl phosphite 0.5 parts by weight were mixed and placed in a room. The gel time was measured at day 1 (comparative example 12) and day 30 (comparative example 13) using the same method (accelerator and curing agent amounts are the same as above).

[0087] The results are shown in Table 3.

[0088] Table 3 Gel time of TH-926 with DOPO after different storage time

[0089]

[0090] From Table 3, comparative example 12 and Table 1, comparative example 1, it can be seen that the gel time of the unsaturated polyester resin with diphenyl phosphite at day 1 is similar to that of the unsaturated polyester resin without diphenyl phosphite, and the yellow index of the cured product is also similar. However, comparative example 13 shows that the gel time of the unsaturated polyester resin with diphenyl phosphite is greatly extended after 30 days of storage, and it still does not cure after 48 hours, and no solid product is obtained, indicating that the gel time of the unsaturated polyester resin with diphenyl phosphite drifts severely with storage time.

[0091] Examples 21-27 show that the introduction of DOPO into the unsaturated polyester resin system does not cause the gel time of the unsaturated polyester resin to drift.

[0092] In the preparation method of the present application, the order of the steps is not limited to the order listed, and for those skilled in the art, changes in the order of the steps without creative effort are also within the scope of protection of the present application. In addition, two or more steps or actions can be performed simultaneously.

[0093] Finally, it should be noted that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the embodiments of the present application. Those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, and it is not necessary or possible to list all the embodiments here. Any obvious changes or variations derived from the essential spirit of the present application still fall within the scope of protection of the present application, and any interpretation as an additional limitation is contrary to the spirit of the present application.

Claims

The application of 1,9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) in the anti-yellowing of unsaturated polyester resins, characterized in that, The introduction of DOPO into the unsaturated polyester resin system can improve the anti-yellowing properties of the solid products formed after the unsaturated polyester resin system is cured.

2. The application according to claim 1, characterized in that, The yellow index of solid products formed by curing unsaturated polyester resin systems containing DOPO after heat treatment at 150°C for 30 minutes, as measured according to standard HG / T 3862—2006, is lower than that of solid products formed by curing unsaturated polyester resin systems without DOPO after heat treatment at 150°C for 30 minutes.

3. The application according to claim 1 or 2, characterized in that, The difference between the yellow index of a solid product formed by curing an unsaturated polyester resin system containing DOPO and the yellow index of a solid product formed by curing an unsaturated polyester resin system without DOPO and the yellow index of a solid product formed by curing an unsaturated polyester resin system without DOPO and the yellow index of a solid product formed by curing an unsaturated polyester resin system containing ...

4. A yellowing-resistant unsaturated polyester resin composition, characterized in that, include: 100 parts by weight of unsaturated polyester resin; 0.01 to 3 parts by weight of DOPO.

5. The anti-yellowing unsaturated polyester resin composition according to claim 4, characterized in that, include: 100 parts by weight of unsaturated polyester resin; 0.03 to 0.20 parts by weight of DOPO.

6. The anti-yellowing unsaturated polyester resin composition according to claim 4 or 5, characterized in that, Unsaturated polyester resin is composed of unsaturated polyester prepolymer and vinyl monomer; Unsaturated polyester prepolymers are linear polymeric compounds with ester bonds and unsaturated C=C double bonds, which are formed by the condensation polymerization of raw materials including unsaturated diacids or anhydrides and diols. Vinyl monomers are molecules containing CH2=CH- and / or Unsaturated olefinic compounds.

7. The anti-yellowing unsaturated polyester resin composition according to claim 6, characterized in that, The vinyl monomer is styrene.

8. The anti-yellowing unsaturated polyester resin composition according to claim 4 or 5, characterized in that, The unsaturated polyester resin is an isophthalic unsaturated polyester resin.

9. The anti-yellowing unsaturated polyester resin composition according to claim 4 or 5, characterized in that, The anti-yellowing unsaturated polyester resin composition also includes a curing agent and an accelerator; For every 100 parts by weight of unsaturated polyester resin, the amount of curing agent is 0.001 to 2 parts by weight, and the amount of accelerator is 0.001 to 2 parts by weight.

10. The anti-yellowing unsaturated polyester resin composition according to claim 9, characterized in that, The curing agent is a peroxide compound, which includes one or more of the following: methyl ethyl ketone peroxide, cyclohexanone peroxide, methyl isobutyl ketone peroxide, benzoyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, 2,4-dichlorobenzoyl peroxide, and dodecyl peroxide. The accelerator is one or more of cobalt organic salts and tertiary amines.

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