Modifier, unsaturated polyester resin cured product, preparation method of modifier and unsaturated polyester resin cured product, and application of modifier and unsaturated polyester resin cured product to cover surface of image capture device

Abstract

The invention discloses a modifier for toughening unsaturated polyester resin. The modifier is characterized in that the modifier is a polyether ester multi-block copolymer composed of an aliphatic polyether block and an aliphatic polyester block. The invention also discloses an unsaturated polyester resin cured product adopting the modifier, a preparation method of the unsaturated polyester resin cured product and application of the unsaturated polyester resin cured product on a cover surface of an image capture device. Compared with the prior art, the modifier provided by the invention can improve the toughness, impact strength and tensile strength of the unsaturated polyester resin cured product.

Description

Technical Field

[0001] The invention relates to the technical field of unsaturated resins, and in particular to a modifier for toughening unsaturated polyester resins and an unsaturated polyester resin solidified product, as well as a preparation method thereof and an application thereof on a cover surface of an image capturing device. Background Art

[0002] With the rapid development of digital technology and network technology, concepts such as the Internet of Everything, Smart City, and Safe City have been proposed and implemented one after another. As the "eyes", terminal image capture devices such as cameras and monitors are becoming more and more important. Terminal image capture devices are placed in every corner of cities, communities, gardens, factories, and rivers to collect real-time images of these areas and provide image data for various sectors of society. These data are used to monitor natural disasters, factory operations, natural resources, etc., providing a reference for the safety of all aspects of society. It can be said that the clarity of the image expression determines the safety level of a certain area within a certain range.

[0003] For the cover of the image capture device, the cover body is generally made of thermosetting resin such as unsaturated polyester resin. In order to improve the mechanical properties of the cover body and enable it to better protect the internal module of the image capture device, the thermosetting resin can be toughened.

[0004] At present, the toughening of unsaturated polyester resin can be generally divided into the following categories: one is to change the chemical composition to synthesize a new type of unsaturated polyester resin, mainly by introducing flexible segments into it, but the cost of toughening modification by this method is high and it is difficult to meet the diverse requirements in practical applications; the second is to toughen by adding inorganic nanoparticles, but due to their high surface energy and surface activity, it is difficult to disperse them evenly in the polymer and it is difficult to achieve the ideal toughening effect; the third is to use thermoplastic resin and unsaturated polyester to form an interpenetrating network or semi-interpenetrating network structure to produce a synergistic effect to improve the toughness of the material; the fourth is to introduce an elastomer (such as rubber) to make it evenly dispersed in the unsaturated polyester resin matrix to form microphase separation to improve the toughness of the unsaturated polyester resin. However, the above two methods may have problems such as poor compatibility, unstable particle size, poor transparency, and reduced strength.

[0005] Block copolymers can combine the excellent properties of multiple polymers to obtain functional polymer materials with superior performance. By designing the molecular structure of block copolymers, their compatibility with unsaturated polyester resins and toughening and strengthening effects can be taken into account. In addition, by adjusting the composition and structure of block copolymers, the morphology of microphase separation can be regulated, playing an important role in the toughening modification of unsaturated polyester resins.

[0006] For example, CN101072828A discloses an amphiphilic block copolymer toughened epoxy vinyl ester and unsaturated polyester resin, wherein the ester resin toughening agent used is an amphiphilic block copolymer containing at least one ester resin miscible block and at least one ester resin immiscible block, so that the toughness of the toughened unsaturated polyester resin cured product is improved. However, the invention mainly focuses on the toughening effect of the full polyether block copolymer in the unsaturated polyester resin, and mainly includes diblock and triblock copolymers. Compared with diblock and triblock copolymers, multiblock copolymers generally have better mechanical properties and have a richer microphase separation structure, therefore, adding them to the unsaturated polyester resin will produce better toughening and strengthening effects.

[0007] Based on the above analysis, there is an urgent need to develop a multi-block copolymer as a toughening modifier for unsaturated polyester resins, so as to be applied to the toughening of unsaturated polyester resins and achieve improvements in their toughness, tensile strength and impact strength. Summary of the invention

[0008] The first technical problem to be solved by the present invention is to provide a modifier for toughening unsaturated polyester resin, which can improve the toughness, impact strength and tensile strength of unsaturated polyester resin cured product, in view of the current status of the prior art.

[0009] The second technical problem to be solved by the present invention is to provide an unsaturated polyester resin cured product with enhanced toughness, impact strength and tensile strength.

[0010] The third technical problem to be solved by the present invention is to provide a method for preparing the above-mentioned unsaturated polyester resin cured product.

[0011] The fourth technical problem to be solved by the present invention is to provide an application of the above-mentioned unsaturated polyester resin cured product on the cover of an image capturing device.

[0012] The technical solution adopted by the present invention to solve the first technical problem is: a modifier for toughening unsaturated polyester resin, characterized in that: the modifier is a polyether ester multi-block copolymer composed of aliphatic polyether blocks and aliphatic polyester blocks, and the general formula of the polyether ester multi-block copolymer is: ; Wherein, a is any integer from 2 to 6; b is any integer between 2 and 11; c is any integer from 2 to 4; d is any integer between 13 and 68; e and f are determined by the contents of aliphatic polyester block and aliphatic polyether block, respectively; The number average molecular weight of the polyetherester multi-block copolymer is 8000-50000 g / mol.

[0013] Preferably, the content of the aliphatic polyether block is 30-85 wt %, the content of the aliphatic polyester block is 15-70 wt %, and the sum of the contents of the aliphatic polyether block and the aliphatic polyester block is 100 wt %.

[0014] Preferably, the aliphatic polyester block is at least one of polyethylene adipate, polybutylene succinate, and polyethylene tridecanoate.

[0015] Preferably, the value of c is 2 or 4. When c is 2, the aliphatic polyether block is polyethylene oxide, and when c is 4, the aliphatic polyether block is polytetrahydrofuran. The number average molecular weight of the polyethylene oxide or polytetrahydrofuran is 600 to 3000 grams per mole.

[0016] The technical solution adopted by the present invention to solve the second technical problem is: an unsaturated polyester resin solidified material using the above-mentioned modifier, characterized in that its raw materials include: unsaturated polyester resin, initiator and modifier.

[0017] Preferably, the mass ratio of the unsaturated polyester resin to the modifier is 100:1 to 10:1.

[0018] Preferably, the mass ratio of the unsaturated polyester resin to the initiator is 200:1 to 40:1.

[0019] Preferably, the unsaturated polyester resin is an orthophthalic unsaturated polyester resin.

[0020] Preferably, the initiator is an organic peroxide.

[0021] Furthermore, the initiator is at least one of di-tert-butyl peroxide, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane, benzoyl peroxide, and tert-butyl perbenzoate.

[0022] The technical solution adopted by the present invention to solve the third technical problem is: a method for preparing the above-mentioned unsaturated polyester resin cured product, characterized in that it includes the following steps: mixing the unsaturated polyester resin with the modifier, heating to 70-110°C, stirring for 10 minutes-2 hours, mixing evenly, and standing to room temperature; adding an initiator to the mixture, mixing evenly and then curing to obtain the desired unsaturated polyester resin cured product.

[0023] The technical solution adopted by the present invention to solve the fourth technical problem is: an application of the above-mentioned unsaturated polyester resin solidified material on the cover surface of the image capturing device.

[0024] Preferably, the image capture device mask comprises The cover body is made of the unsaturated polyester resin solidified material, is hollow inside and has an opening at the rear, and has a mounting hole on the front side wall of the cover body; and The transparent panel is installed in the installation hole of the cover body.

[0025] Compared with the prior art, the advantages of the present invention are: (1) The modifier for toughening unsaturated polyester resin proposed in the present invention is a polyether ester multi-block copolymer composed of aliphatic polyether blocks and aliphatic polyester blocks. On the one hand, the aliphatic polyether blocks have good compatibility with the unsaturated polyester resin matrix and provide good flexibility and impact strength. Therefore, the modifier of the present invention can be well dissolved in the unsaturated polyester resin matrix and evenly dispersed. On the other hand, during the curing process, the polyether ester multi-block copolymer can undergo microphase separation, and the toughening effect can be achieved by using a relatively small amount of the polyether ester multi-block copolymer. (2) After the modifier of the present invention is added to the unsaturated polyester resin matrix, the energy dissipation pathway is improved due to the microphase separation generated in the system, and the toughness, impact strength and tensile strength of the unsaturated polyester resin cured product are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a stress-strain curve diagram of the unsaturated polyester resin cured product obtained in Example 1 of the present invention; Figure 2 is a stress-strain curve diagram of the unsaturated polyester resin cured product obtained in Example 7 of the present invention; Figure 3 is a stress-strain curve diagram of the unsaturated polyester resin cured product obtained in Example 9 of the present invention; Figure 4 is a stress-strain curve diagram of the unsaturated polyester resin cured product obtained in Example 10 of the present invention; Figure 5 is a stress-strain curve diagram of the unsaturated polyester resin cured product obtained in Comparative Example 1 of the present invention; Figure 6 A schematic diagram of the three-dimensional structure of a mask surface in an embodiment of an image capturing device of the present invention; Figure 7 for Figure 6 A schematic diagram of the three-dimensional structure in another direction; Figure 8 for Figure 6 Schematic diagram of the three-dimensional structure of the middle cover body. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the accompanying drawings.

[0028] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods, and the materials, reagents, etc. used are all available from commercial sources unless otherwise specified.

[0029] In the following examples and comparative examples of the present invention, the unsaturated polyester resin is an orthophthalic unsaturated polyester resin (produced by Jinling Aliance Resin Co., Ltd., with a trade name of Palapreg P17-902). Embodiment 1:

[0030] The modifier used in this embodiment is a polyether ester multi-block copolymer mBCP-1 composed of polyethylene glycol tridecanedioate (PEB) and polyethylene oxide (PEO, molecular weight 2000 g / mol); wherein the polyether ester multi-block copolymer mBCP-1 is prepared by mixing musk T (10.0 g), polyethylene glycol (20.0 g, molecular weight 2000 g / mol) and 15.0 μL tetrabutyl titanate, passing nitrogen, mechanical stirring, and reacting at 220 ° C for 60 min; mBCP-1 is subjected to quantitative nuclear magnetic hydrogen spectrum test, the polyester block is polyethylene glycol tridecanedioate (PEB), the content is 22%; the polyether block is polyethylene oxide (PEO), the content is 78%, and the molecular weight of mBCP-1 is 18.7 kg / mol; 50.0 g of unsaturated polyester resin was mixed with 1.5 g of mBCP-1, heated to 100 °C, stirred for 40 minutes, mixed evenly, and allowed to stand to room temperature; 0.5 g of tert-butyl peroxybenzoate was mixed with it, mixed evenly, and cured at 110 °C for 40 minutes, and cured at 120 °C and 140 °C for 20 minutes in sequence to obtain an unsaturated polyester resin cured product UPR-1. Embodiment 2:

[0031] The modifier used in this embodiment is the same as that in Example 1, except that: 50.0 g of unsaturated polyester resin is mixed with 0.5 g of mBCP-1, the temperature is raised to 100 ° C, stirred for 20 minutes, mixed evenly, and allowed to stand to room temperature; 0.5 g of tert-butyl peroxybenzoate is mixed therewith, mixed evenly, and then cured at 110 ° C for 40 minutes, and cured at 120 ° C and 140 ° C for 20 minutes in sequence to obtain an unsaturated polyester resin cured product UPR-2. Embodiment 3:

[0032] The modifier used in this embodiment is the same as that in Example 1, except that: 50.0 g of unsaturated polyester resin is mixed with 2.5 g of mBCP-1, the temperature is raised to 100 ° C, stirred for 1 hour, mixed evenly, and allowed to stand to room temperature; 0.5 g of tert-butyl peroxybenzoate is mixed therewith, mixed evenly, and then cured at 110 ° C for 40 minutes, and cured at 120 ° C and 140 ° C for 20 minutes in sequence to obtain an unsaturated polyester resin cured product UPR-3. Embodiment 4:

[0033] The modifier used in this embodiment is a polyether ester multi-block copolymer mBCP-2 composed of polyethylene glycol tridecanedioate (PEB) and polyethylene oxide (PEO, molecular weight of 2000 g / mol); wherein the polyether ester multi-block copolymer mBCP-2 is prepared by mixing musk T (10.0 g), polyethylene glycol (20.0 g, molecular weight of 2000 g / mol) and 15.0 μL tetrabutyl titanate, passing nitrogen, mechanical stirring, and reacting at 220 ° C for 180 min; mBCP-2 is subjected to quantitative nuclear magnetic hydrogen spectrum test, the polyester block is polyethylene glycol tridecanedioate (PEB), the content is 23%; the polyether block is polyethylene oxide (PEO), the content is 77%, and the molecular weight of mBCP-2 is 35.1 kg / mol; 50.0 g of unsaturated polyester resin was mixed with 1.5 g of mBCP-2, heated to 110 °C, stirred for 40 minutes, mixed evenly, and allowed to stand to room temperature; 0.5 g of tert-butyl peroxybenzoate was mixed therewith, mixed evenly, and cured at 110 °C for 40 minutes, and cured at 120 °C and 140 °C for 20 minutes in sequence to obtain an unsaturated polyester resin cured product UPR-4. Embodiment 5:

[0034] The modifier used in this embodiment is a polyether ester multi-block copolymer mBCP-3 composed of polyethylene glycol tridecanedioate (PEB) and polyethylene oxide (PEO, molecular weight 2000 g / mol); wherein the polyether ester multi-block copolymer mBCP-3 is prepared by mixing musk T (15.0 g), polyethylene glycol (15.0 g, molecular weight 2000 g / mol) and 15.0 μL tetrabutyl titanate, passing nitrogen, mechanical stirring, and reacting at 220 ° C for 60 min; mBCP-3 is subjected to quantitative nuclear magnetic hydrogen spectrum test, the polyester block is polyethylene glycol tridecanedioate (PEB), the content is 42%; the polyether block is polyethylene oxide (PEO), the content is 58%, and the molecular weight of mBCP-3 is 11.7 kg / mol; The preparation process of the unsaturated polyester resin cured product is the same as that of Example 1, except that the modifier mBCP-3 of the same mass is used instead of the modifier mBCP-1 to obtain the unsaturated polyester resin cured product UPR-5. Embodiment 6:

[0035] The modifier used in this embodiment is a polyether ester multi-block copolymer mBCP-4 composed of polyethylene adipate (PEA) and polyethylene oxide (PEO, molecular weight of 3000 g / mol); wherein the polyether ester multi-block copolymer mBCP-4 is prepared by mixing cyclic oligomeric polyethylene adipate (10.0 g), polyethylene glycol (20.0 g, molecular weight of 3000 g / mol) and 15.0 μL tetrabutyl titanate, passing nitrogen, mechanical stirring, and reacting at 220 ° C for 60 min; mBCP-4 is subjected to quantitative nuclear magnetic hydrogen spectrum test, the polyester block is polyethylene adipate (PEA), the content is 21%; the polyether block is polyethylene oxide (PEO), the content is 79%, and the molecular weight of mBCP-4 is 10.6 kg / mol; The preparation process of the unsaturated polyester resin cured product is the same as that of Example 1, except that the modifier mBCP-4 of the same mass is used instead of the modifier mBCP-1 to obtain the unsaturated polyester resin cured product UPR-6. Embodiment 7:

[0036] The modifier used in this embodiment is a polyether ester multi-block copolymer mBCP-5 composed of polyethylene glycol tridecanedioate (PEB) and polyethylene oxide (PEO, molecular weight 600 g / mol); wherein the polyether ester multi-block copolymer mBCP-5 is prepared by mixing musk T (15.0 g), polyethylene glycol (15.0 g, molecular weight 600 g / mol) and 15.0 μL tetrabutyl titanate, passing nitrogen, mechanical stirring, and reacting at 220 ° C for 60 min; mBCP-5 is subjected to quantitative nuclear magnetic hydrogen spectrum test, the polyester block is polyethylene glycol tridecanedioate (PEB), the content is 58%; the polyether block is polyethylene oxide (PEO), the content is 42%, and the molecular weight of mBCP-5 is 10.6 kg / mol; The preparation process of the unsaturated polyester resin cured product is the same as that of Example 1, except that the modifier mBCP-5 of the same mass is used instead of the modifier mBCP-1 to obtain the unsaturated polyester resin cured product UPR-7. Embodiment 8:

[0037] The modifier used in this embodiment is a polyether ester multi-block copolymer mBCP-6 composed of polybutylene succinate (PBS) and polyethylene oxide (PEO, molecular weight of 2000 g / mol); wherein the polyether ester multi-block copolymer mBCP-6 is prepared by mixing cyclic oligomeric polybutylene succinate (10.0 g), polyethylene glycol (20.0 g, molecular weight of 2000 g / mol) and 15.0 μL tetrabutyl titanate, passing nitrogen, mechanical stirring, and reacting at 220 ° C for 180 min; mBCP-6 is subjected to quantitative nuclear magnetic hydrogen spectrum test, the polyester block is polybutylene succinate (PBS), the content is 33%; the polyether block is polyethylene oxide (PEO), the content is 67%, and the molecular weight of mBCP-6 is 40.7 kg / mol; The preparation process of the unsaturated polyester resin cured product is the same as that of Example 1, except that an equal mass of the modifier mBCP-6 is used instead of the modifier mBCP-1, and 1.0 g of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane is used instead of 0.5 g of tert-butyl peroxybenzoate to obtain the unsaturated polyester resin cured product UPR-8. Embodiment 9:

[0038] The modifier used in this embodiment is a polyether ester multi-block copolymer mBCP-7 composed of polybutylene succinate (PBS) and polyethylene oxide (PEO, molecular weight of 2000 g / mol); wherein the polyether ester multi-block copolymer mBCP-7 is prepared by mixing cyclic oligomeric polybutylene succinate (10.0 g), polyethylene glycol (30.0 g, molecular weight of 2000 g / mol) and 15.0 μL tetrabutyl titanate, passing nitrogen, mechanical stirring, and reacting at 220 ° C for 180 min; mBCP-7 is subjected to quantitative nuclear magnetic hydrogen spectrum test, the polyester block is polybutylene succinate (PBS), the content is 25%; the polyether block is polyethylene oxide (PEO), the content is 75%, and the molecular weight of mBCP-7 is 45.7 kg / mol; The preparation process of the unsaturated polyester resin cured product is the same as that of Example 1, except that the modifier mBCP-7 of the same mass is used instead of the modifier mBCP-1 to obtain the unsaturated polyester resin cured product UPR-9.

[0039] Embodiment 10: The modifier used in this embodiment is a polyether ester multi-block copolymer mBCP-8 composed of polyethylene tridecanedioate (PEB) and polytetrahydrofuran (PTMO, molecular weight of 1000 g / mol); wherein the polyether ester multi-block copolymer mBCP-8 is prepared by mixing musk T (15.0 g), polytetrahydrofuran diol (15.0 g, molecular weight of 1000 g / mol) and 15.0 μL tetrabutyl titanate, passing nitrogen, mechanical stirring, and reacting at 220 ° C for 60 min; mBCP-8 is subjected to quantitative nuclear magnetic hydrogen spectrum test, the polyester block is polyethylene tridecanedioate (PEB), the content is 44%; the polyether block is polytetrahydrofuran (PTMO), the content is 56%, and the molecular weight of mBCP-8 is 14.2 kg / mol; The preparation process of the unsaturated polyester resin cured product is the same as that of Example 4, except that the modifier mBCP-8 is used in place of the modifier mBCP-2 with the same mass to obtain the unsaturated polyester resin cured product UPR-10.

[0040] Embodiment 11: The modifier used in this embodiment is a polyether ester multi-block copolymer mBCP-9 composed of polyethylene tridecanedioate (PEB) and polytetrahydrofuran (PTMO, molecular weight of 2900 g / mol); wherein the polyether ester multi-block copolymer mBCP-9 is prepared by mixing musk T (10.0 g), polytetrahydrofuran diol (20.0 g, molecular weight of 2900 g / mol) and 15.0 μL tetrabutyl titanate, passing nitrogen, mechanical stirring, and reacting at 220 ° C for 60 min; mBCP-9 is subjected to quantitative nuclear magnetic hydrogen spectrum test, the polyester block is polyethylene tridecanedioate (PEB), the content is 28%; the polyether block is polyethylene oxide (PTMO), the content is 72%, and the molecular weight of mBCP-9 is 11.5 kg / mol; 50.0 g of unsaturated polyester resin was mixed with 1.5 g of mBCP-9, heated to 110 °C, stirred for 1 hour, mixed evenly, and allowed to stand to room temperature; 0.5 g of tert-butyl perbenzoate was mixed therewith, mixed evenly, and cured at 110 °C for 40 minutes, and then cured at 120 °C and 140 °C for 20 minutes respectively to obtain an unsaturated polyester resin cured product UPR-11.

[0041] Comparative Example 1: 50.0 g of unsaturated polyester resin and 0.5 g of tert-butyl peroxybenzoate were mixed, and after mixing evenly, the mixture was cured at 110° C. for 40 minutes, and then cured at 120° C. and 140° C. for 20 minutes in sequence to obtain an unsaturated polyester resin cured product UPR.

[0042] Comparative Example 2: The modifier used in this comparative example is a polyether ester multi-block copolymer mBCP-10 composed of polyethylene terephthalate (PET) and polytetrahydrofuran (PTMO, molecular weight of 2000 g / mol); wherein the polyether ester multi-block copolymer mBCP-10 is prepared by mixing cyclic oligoethylene terephthalate (10.0 g), polytetrahydrofuran diol (20.0 g, molecular weight of 2000 g / mol) and 15.0 μL tetrabutyl titanate, passing nitrogen, mechanically stirring, and reacting at 220 °C for 60 min; mBCP-10 is subjected to quantitative nuclear magnetic hydrogen spectrum test, and the polyester block is polyethylene terephthalate (PEB) with a content of 33%; the polyether block is polytetrahydrofuran (PTMO) with a content of 67%; 50.0 g of unsaturated polyester resin was mixed with 1.5 g of mBCP-10, heated to 110 °C, and stirred for 2 hours. mBCP-10 is incompatible with unsaturated polyester resin, so it is difficult to toughen the unsaturated polyester resin.

[0043] The performance test steps are as follows: (1) Tensile property test: The tensile properties of the unsaturated polyester resin cured product were tested using an Instron-3365 universal material testing machine (tensile rate: 10 mm / min, temperature: 20.0°C, humidity: 70.0%); (2) Impact resistance test: The simply supported beam notch impact resistance of unsaturated polyester resin cured material was tested using an FPP-01A impact testing machine.

[0044] The impact toughness and tensile strength of the unsaturated polyester resin cured products obtained in all the above examples and Comparative Example 1 are shown in Table 1 (the impact strength is used to characterize the toughness of the unsaturated polyester resin cured product). The stress-strain curves of the unsaturated polyester resin cured products obtained in Example 1, Example 7, Example 9, Example 10 and Comparative Example 1 are shown in Table 1. Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 shown.

[0045] Table 1

[0046] From Table 1 and Figures 1 to 5 It can be seen that after adding the modifier of the present invention, the toughness and strength of the unsaturated polyester resin cured product are significantly improved, the impact strength can be increased by more than 90%, the strength can be increased by more than 30%, and the elongation at break is increased from less than 2% to about 4%.

[0047] The unsaturated polyester resin cured product can be applied to the cover of an image capturing device.

[0048] like Figures 6 to 8 FIG. 1 is a preferred embodiment of the image capturing device of the present invention. The image capturing device can be a camera, a monitor, etc. The cover of the image capturing device includes a cover body 1 and a transparent panel 2.

[0049] The cover body 1 is made of the unsaturated polyester resin solidified material. The cover body 1 is roughly a cuboid, hollow inside and open at the rear, with a mounting hole 11 on the front side wall of the cover body 1, the mounting hole 11 is a stepped hole with a stepped surface 111 facing the rear side.

[0050] The transparent panel 2 is installed in the installation hole 11 of the cover body 1, and the front side of the edge of the transparent panel 2 is arranged close to the step surface 111 to prevent foreign matter from entering.

Claims

1. A modifier for toughening unsaturated polyester resin, characterized in that: The modifier is a polyether ester multi-block copolymer composed of aliphatic polyether blocks and aliphatic polyester blocks, and the general formula of the polyether ester multi-block copolymer is: ； Wherein, a is any integer from 2 to 6; b is any integer between 2 and 11; c is any integer from 2 to 4; d is any integer between 13 and 68; e and f are determined by the contents of aliphatic polyester block and aliphatic polyether block, respectively; The number average molecular weight of the polyetherester multi-block copolymer is 8000-50000 g / mol.

2. The modifier according to claim 1, characterized in that: The content of the aliphatic polyether block is 30-85 wt %, the content of the aliphatic polyester block is 15-70 wt %, and the sum of the contents of the aliphatic polyether block and the aliphatic polyester block is 100 wt %.

3. The modifier according to claim 1, characterized in that: The aliphatic polyester block is at least one of polyethylene adipate, polybutylene succinate and polyethylene tridecanoate.

4. The modifying agent according to any one of claims 1 to 3, characterized in that: The value of c is 2 or 4.

5. An unsaturated polyester resin cured product using the modifier according to any one of claims 1 to 4, characterized in that: The raw materials include: unsaturated polyester resin, initiator and modifier.

6. The unsaturated polyester resin cured product according to claim 5, characterized in that: The mass ratio of the unsaturated polyester resin to the modifier is 100:1 to 10:1; The mass ratio of the unsaturated polyester resin to the initiator is 200:1 to 40:

1.

7. The unsaturated polyester resin cured product according to claim 5, characterized in that: The unsaturated polyester resin is an orthophthalic unsaturated polyester resin; The initiator is an organic peroxide.

8. A method for preparing the unsaturated polyester resin cured product according to any one of claims 5 to 7, characterized in that The method comprises the following steps: mixing unsaturated polyester resin and modifier, heating to 70-110°C, stirring for 10 minutes-2 hours, mixing evenly, and standing to room temperature; adding initiator to the mixture, mixing evenly, and curing to obtain the desired unsaturated polyester resin cured product.

9. Use of the cured unsaturated polyester resin according to any one of claims 5 to 7 on a cover of an image capturing device.

10. The use according to claim 9, characterized in that: The image capture device mask includes The cover body (1) is made of the unsaturated polyester resin solidified material, is hollow inside and has an opening at the rear, and has a mounting hole (11) on the front side wall of the cover body (1); and A transparent panel (2) is installed in the installation hole (11) of the cover body (1).

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