Unsaturated polyester resin composition and molded product thereof
By using a combination of low styrene content and high boiling point comonomers in unsaturated polyester resins, the problems of strong styrene volatility and large curing volume shrinkage in the prior art are solved, and low volatility and low shrinkage are achieved The unsaturated polyester resin composition protects the health and environment of the operator while improving the performance of the product.
Patent Information
- Application Number
- CN202110303206.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Priority Date
- 2020-10-26
- Filing Date
- 2021-03-22
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2041-03-22
AI Technical Summary
The high styrene content in existing unsaturated polyester resins leads to strong volatility, which harms the health and environment of operators, and the volume shrinkage during curing greatly affects the size and gloss of the product.
Low styrene volatile unsaturated polyester resin compositions, which include 30 to 60 parts by weight of unsaturated polyester resin and 2 to 30 parts by weight of comonomer, methylstyrene, hydroxyacrylate monomers in the comonomer The weight ratio of the bulk and diallyl phthalate is 6:3:1, the styrene content is less than 5 wt%. The high boiling point comonomer is used to reduce volatile organic matter and improve the volume shrinkage during curing.
It effectively reduces the volatile nature of styrene and has less organic volatility, protects the health of operators, reduces environmental pollution, and improves the dimensional stability and surface gloss of the products.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to an unsaturated polyester resin composition and a molded product thereof, in particular to an unsaturated polyester resin composition with low styrene volatility and a molded product thereof. Background Art
[0002] Unsaturated polyester resin is made by esterification reaction between diol and dibasic acid at 190 to 220℃. After reaching the expected acid value (or viscosity), it is diluted and dissolved with a certain amount of styrene monomer to form a viscous liquid, which is unsaturated polyester resin. Unsaturated polyester resin can be hardened and formed at room temperature and pressure. The hardened product of unsaturated polyester resin has good mechanical strength and electrical properties, and has excellent acid corrosion resistance, weather resistance and water resistance, and can save heating devices. Therefore, unsaturated polyester resin is widely used in injection molding, sheet molding compound (SMC) or bulk molding compound (BMC) manufacturing processes, and various plastic industry products.
[0003] Unsaturated polyester resin contains double bonds in its resin molecular chain, which can copolymerize with double-bond monomers to form a three-dimensional structure, so it has excellent mechanical properties and chemical corrosion resistance. Generally speaking, the existing technology uses styrene as a diluent and comonomer for unsaturated polyester resin, and its usage accounts for up to 30 to 40% of the total resin. However, because styrene has a low boiling point, is easy to volatilize, has a high vapor pressure at room temperature, and has a special odor and toxicity, it poses a great threat to the health of on-site operators and the environmental load. Therefore, the development of unsaturated polyester resins with low styrene content has become one of the important issues that this business wants to solve. Summary of the invention
[0004] The technical problem to be solved by the present invention is to provide a low styrene volatility unsaturated polyester resin composition in view of the deficiencies in the prior art.
[0005] In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide a low styrene volatile unsaturated polyester resin composition, which comprises: 30 to 60 parts by weight of unsaturated polyester resin and 2 to 30 parts by weight of comonomer. The comonomer comprises: (a) methyl styrene; (b) hydroxy acrylate monomer; and (c) diallyl phthalate monomer, and the weight ratio of the contents of (a), (b) and (c) in the comonomer is 6:3:1.
[0006] Furthermore, the styrene content of the unsaturated polyester resin composition is less than 5 wt %.
[0007] Furthermore, the unsaturated polyester resin is selected from the group consisting of phthalic acid-based unsaturated polyesters, isophthalic acid-based unsaturated polyesters and terephthalic acid-based unsaturated polyesters.
[0008] Furthermore, the hydroxy acrylate monomer is selected from the group consisting of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and pentaerythritol triacrylate.
[0009] Furthermore, the diallyl phthalate monomer is selected from the group consisting of diallyl phthalate and diallyl isophthalate.
[0010] Furthermore, the total weight percentage of the comonomer based on the unsaturated polyester resin and the comonomer is between 2 and 50 wt %.
[0011] In order to solve the above technical problems, another technical solution adopted by the present invention is to provide a molded product, which is formed by heating and curing the unsaturated polyester resin composition of the present invention.
[0012] One of the beneficial effects of the present invention is that the unsaturated polyester resin composition and the molded product thereof provided by the present invention can obtain an unsaturated polyester resin composition with low styrene volatility through the technical scheme of "the comonomer includes: (a) methyl styrene; (b) hydroxy acrylate monomer; and (c) diallyl phthalate monomer" and "in the comonomer, the weight ratio of the content of (a), (b) and (c) is 6:3:1".
[0013] To further understand the features and technical contents of the present invention, please refer to the following detailed description of the present invention. However, the contents provided are only for reference and description and are not intended to limit the present invention. DETAILED DESCRIPTION
[0014] The following is an explanation of the implementation methods of the "unsaturated polyester resin composition and its molded product" disclosed in the present invention through specific specific examples. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the concept of the present invention. The following embodiments will further explain the relevant technical content of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention. In addition, the term "or" used in this article may include any one or more combinations of the associated listed items depending on the actual situation. The article "one" is used in this article to indicate one or more than one (i.e., at least one) grammatical object of the article. For example, "one epoxy group" refers to one epoxy group or more than one epoxy group.
[0015] The present invention provides a low styrene volatile unsaturated polyester resin composition, which comprises: 30 to 60 parts by weight of an unsaturated polyester resin and 2 to 30 parts by weight of a comonomer, wherein the comonomer comprises: (a) methyl styrene; (b) a hydroxy acrylate monomer; and (c) a diallyl phthalate monomer, and the weight ratio of the contents of (a), (b) and (c) in the comonomer is 6:3:1.
[0016] Preferably, the weight ratio of the unsaturated polyester resin to the comonomer is 4:1 to 7:1.
[0017] More specifically, the unsaturated polyester resin is selected from the group consisting of phthalic acid-based unsaturated polyesters, isophthalic acid-based unsaturated polyesters and terephthalic acid-based unsaturated polyesters. Preferably, the unsaturated polyester resin has a degree of polymerization of 2 to 8 and a viscosity of 5000 to 30000 cps at 25°C.
[0018] More specifically, the hydroxyacrylate monomer is selected from the group consisting of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and pentaerythritol triacrylate.
[0019] More specifically, the hydroxyacrylate monomer is selected from the group consisting of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and pentaerythritol triacrylate.
[0020] More specifically, the diallyl phthalate monomer is selected from the group consisting of diallyl phthalate and diallyl isophthalate.
[0021] Preferably, the total weight percentage of the comonomer based on the unsaturated polyester resin and the comonomer is between 5 and 20 wt%. Specifically, the comonomer used in the present invention has a high boiling point, a low vapor pressure at room temperature, is not easy to volatilize, and has less volatile organic compounds (VOC), which can improve production conditions, protect the health of operators and reduce environmental pollution.
[0022] In addition, the unsaturated polyester resin in the prior art has a large volume shrinkage rate when solidified, which further affects the size and surface gloss of the product. The comonomer selected in the present invention can effectively improve this problem without affecting other physical properties.
[0023] Furthermore, the unsaturated polyester resin composition of the present invention may further include fillers such as glass fiber, asbestos fiber, carbon fiber, boron fiber, mica, silica, talc, silicate, calcium carbonate, metal oxide and carbon black to increase its mechanical strength.
[0024] As required, the unsaturated polyester resin composition may further include other general resin additives, such as, for example, ultraviolet absorbers (benzophenone, benzotriazole, cyanoacrylate, tris-based, salicylate, etc.), light stabilizers (hindered amine, etc.), antioxidants (hindered phenol, amine, copper, organic phosphorus peroxide decomposers, organic sulfur peroxide decomposers, etc.), sunscreens (rutile titanium oxide, chromium oxide, cerium oxide, etc.), metal deactivators (benzotriazole, etc.), matting agents (organic nickel, etc.), natural waxes, synthetic waxes, higher fatty acids, metal salts of higher fatty acids, antifogging agents, mildew inhibitors, antibacterial agents, deodorants, plasticizers, antistatic agents, surfactants, polymerization inhibitors, crosslinking agents, dyes, colorants (carbon black, titanium oxide, red iron oxide, etc.), oxide) and other pigments, dyes, etc.), sensitizers, hardening accelerators, diluents, fluidity regulators, defoamers, foaming agents, leveling agents, adhesives, tackifiers, tackifiers, lubricants, release agents, lubricants, solid lubricants (polytetrafluoroethylene, low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ultra-high molecular weight polyethylene and other polyolefin resins, graphite, molybdenum disulfide, tungsten disulfide, boron nitride, etc.), nucleating agents, reinforcing agents, compatibilizers, conductive materials (carbon, metal, metal oxide, etc.), anti-blocking agents, anti-tracking agents, light storage agents, various stabilizers, etc. However, the above examples are only feasible embodiments of the present invention and are not intended to limit the present invention.
[0025] The various conditions for synthesizing the unsaturated polyester resin composition of the present invention need to be appropriately set according to the raw materials used or their amounts, but generally speaking, esterification is carried out at a temperature of 140 to 230° C. under pressure or reduced pressure in a stream of an inert gas such as nitrogen. In the esterification reaction, an esterification catalyst can be used as required. Examples of catalysts include: manganese acetate, dibutyltin oxide, stannous oxalate, zinc acetate, and cobalt acetate, etc., which can be used alone or in combination.
[0026] The present invention further provides a molded product, which is formed by heating and curing the unsaturated polyester resin composition of the present invention. In other words, the unsaturated polyester resin composition of the present invention can be prepared into SMC (sheet molding compound), TMC (thick molding compound) or BMC (bulk molding compound) according to the above-mentioned ratio composition by a conventional mixing and impregnation method.
[0027] The molded article of the unsaturated polyester resin composition according to the present invention can be prepared by heating and molding the unsaturated polyester resin composition in a compression molding machine or an injection molding machine at a predetermined temperature and a predetermined pressure. For example, the unsaturated polyester resin composition is cured at a pressure of 1 to 12 MPa and a temperature of 80 to 160°C.
[0028] Example
[0029] The present invention is further explained by the following examples. The unsaturated polyester resin composition was uniformly mixed according to the components and contents shown in Table 1 to prepare a sheet-like kneaded product.
[0030] Table 1
[0031]
[0032]
[0033] Test Results
[0034] The unsaturated polyester resin composition of the present invention can be kneaded at a temperature of 80 to 160° C. and a pressure of 10 to 120 kgf / cm 2 The molded article is molded by a compression or injection molding machine under a pressure of , and the physical properties thereof are further tested according to the following method, and the test results are recorded in Table 2.
[0035] Table 2
[0036]
[0037]
[0038] [Beneficial Effects of Embodiments]
[0039] One of the beneficial effects of the present invention is that the unsaturated polyester resin composition provided by the present invention can obtain an unsaturated polyester resin composition with low styrene volatility through the technical scheme of "the comonomer includes: (a) methyl styrene; (b) hydroxy acrylate monomer; and (c) diallyl phthalate monomer" and "the weight ratio of the comonomer (a), (b), and (c) is 6:3:1". In more detail, the unsaturated polyester resin still contains a small amount of styrene monomer (Styrene Monomer, SM). By using the composition of the present invention, the styrene content of the unsaturated polyester resin composition can be effectively reduced to less than 5wt%.
[0040] Furthermore, the comonomer used in the present invention has a high boiling point, a low vapor pressure at room temperature, is not easily volatile, and has less volatile organic compounds (VOCs), which can improve production conditions, protect the health of operators, and reduce environmental pollution.
[0041] In addition, the unsaturated polyester resin in the prior art has a large volume shrinkage when solidified, which further affects the size and surface gloss of the product. The comonomer selected by the present invention can effectively improve this problem and provide an unsaturated polyester resin composition with a low shrinkage.
[0042] The contents disclosed above are only preferred feasible embodiments of the present invention, and are not intended to limit the protection scope of the claims of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention specification are included in the protection scope of the claims of the present invention.
Claims
1. An unsaturated polyester resin composition, characterized in that The unsaturated polyester resin composition comprises: 30 to 60 parts by weight of an unsaturated polyester resin; and 2 to 30 parts by weight of comonomers comprising: (a) Methylstyrene; (b) a hydroxy acrylate monomer selected from the group consisting of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, 4-hydroxybutyl acrylate and pentaerythritol triacrylate; and (c) a diallyl phthalate monomer, wherein the diallyl phthalate monomer is selected from the group consisting of diallyl phthalate and diallyl isophthalate; Wherein, the weight ratio of the contents of (a), (b) and (c) in the comonomer is 6:3:1; The unsaturated polyester resin is selected from the group consisting of phthalic acid type unsaturated polyester, isophthalic acid type unsaturated polyester and terephthalic acid type unsaturated polyester.
2. The unsaturated polyester resin composition according to claim 1, characterized in that The unsaturated polyester resin composition has a styrene content of less than 5 wt %.
3. The unsaturated polyester resin composition according to claim 1, characterized in that The total weight percentage of the comonomer based on the unsaturated polyester resin and the comonomer is between 5 and 20 wt %.
4. A molded product, characterized in that The molded product is formed by heating and curing the unsaturated polyester resin composition according to claim 1.