A glass fiber sizing for smc and its preparation method, product and application

Abstract

The application discloses a glass fiber sizing agent for SMC, which comprises effective components and water; the solid content of the sizing agent is 3.6-12.6%; the solid mass percentage of each component of the effective components in the total solid mass of the sizing agent is shown as follows: coupling agent 9.5-15.0%, film forming agent 36.0-59.0%, toughening agent 8.5-21.0%, lubricant 9.0-20.0% and antistatic agent 7.0-12.0%; wherein the toughening agent is organic silicon modified water-based polyurethane emulsion; the film forming agent is a mixture of a first film forming agent and a second film forming agent, the mass ratio of the first film forming agent to the second film forming agent is 1:1-1:3.5, the first film forming agent is double crosslinking monomer modified PVAc emulsion, and the second film forming agent is polyester modified epoxy emulsion. The glass fiber yarn produced by using the sizing agent has good surface smoothness and good wear resistance, so that the fiber is not easy to produce glass fiber hair in the production and use process; and the polyester resin has good compatibility, strong interface combination, and can significantly improve the mechanical properties of products.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sizing for glass fiber, in particular to a kind of glass fiber sizing for ultra-low hair SMC, and the preparation method, product and application of the sizing. BACKGROUND

[0002] SMC product has many advantages such as light weight, high strength, corrosion resistance, good designability, easy forming, easy coloring, etc., and has been widely used in the fields of shell, chassis, bumper and spoiler in automobile industry, high-voltage switch cabinet and rectifier box in electrical industry, water tank plate, waterproof plate, bathroom facilities in building industry. With the continuous improvement of technology, SMC manufacturers have put forward higher requirements for production continuity, stability and uniformity of sheet. In order to meet the needs of downstream customers, glass fiber manufacturers must develop SMC special yarn with lower hair. If the yarn is not wear-resistant, it is more likely to produce hair in the process of cutting and using, which will accumulate in the knife roll and fall into the sheet, causing local uneven distribution of glass fiber. Customers usually need to stop production to clean the accumulated hair, which reduces production efficiency and production stability. In addition, the slipperiness and cutting property of yarn are also important. Yarn with good slipperiness can ensure its smooth passing through plastic pipe and threading through porcelain eye without generating a large amount of hair; yarn with good cutting property can ensure that the yarn is cut off in one stroke, avoiding the hair generated by repeated cutting. SUMMARY

[0003] The present application aims to provide a kind of glass fiber sizing for ultra-low hair SMC, the surface of glass fiber coated by the sizing has good slipperiness and wear resistance, so that the fiber is not easy to produce glass fiber hair in the process of production and use; and has good compatibility with polyester resin, strong interface bonding, which can significantly improve the mechanical properties of product.

[0004] In order to achieve the above technical effects, the present application realizes the following technical scheme:

[0005] According to one aspect of the present application, a kind of glass fiber sizing for SMC is provided, the sizing comprises effective component and water; the solid content of the sizing is 3.6% to 12.6%; the effective component comprises coupling agent, film forming agent, toughening agent, lubricant and antistatic agent; the solid mass of each effective component of the sizing accounts for the percentage of total solid mass of the sizing as follows:

[0006]

[0007]

[0008] Among them, the toughening agent is organic silicon modified water-based polyurethane emulsion;

[0009] The film-forming agent is a mixture of a first film-forming agent and a second film-forming agent; the first film-forming agent is a double crosslinking monomer modified PVAc emulsion; the second film-forming agent is a polyester modified epoxy emulsion; and the mass ratio of the first film-forming agent to the second film-forming agent is 1:1 to 1:3.5.

[0010] The solid mass percentage of each effective component of the infiltrating agent in the total solid mass of the infiltrating agent is shown as follows:

[0011]

[0012] The lubricant is a composition of oleic acid diethanolamide and tall oil diethanolamide mixed in any ratio.

[0013] The coupling agent is a silane coupling agent containing a methacryloyloxy group.

[0014] The antistatic agent is an inorganic salt containing lithium.

[0015] The organosilicon modified waterborne polyurethane emulsion is prepared by dispersing a product of reaction of toluene diisocyanate, hydroxyl-terminated polydimethylsiloxane and polyisopropylene glycol in water, with dimethylolpropionic acid as a chain extender.

[0016] The double crosslinking monomer modified PVAc emulsion is prepared by using a semi-continuous seed emulsion polymerization method, with diallyl phthalate as a pre-crosslinking monomer and vinyltriethoxysilane as a post-crosslinking monomer.

[0017] The polyester modified epoxy emulsion is prepared by emulsifying an epoxy resin with an unsaturated polyester as an emulsifying agent.

[0018] The epoxy resin is at least one of bisphenol A type epoxy resin, bisphenol S type epoxy resin and bisphenol F type epoxy resin; and the epoxy equivalent weight of the epoxy resin is 700 to 3600 g / eq.

[0019] The roles and contents of the components in the glass infiltrating agent for SMC are shown as follows:

[0020] The coupling agent of the present application is selected from silane coupling agent (general structure YSiX3). In the general structure, Y is an organic end, usually an alkene or a hydrocarbon group with amino, mercapto, epoxy, azide and isocyanate groups and other functional groups; X is a hydrolyzable group, such as chlorine, alkoxy and the like. Due to this special chemical structure, silane coupling agent can be used as a bridge between inorganic glass fiber and organic polymer film-forming agent, so that the entire infiltration agent film can be fixed on the surface of the glass fiber through chemical bonds, thereby maintaining the good bunching, toughness and stiffness of the glass fiber during processing or cutting. Preferably, the coupling agent of the present application is selected from a silane coupling agent containing methacryloxy, which can form a stable bond with the selected film-forming agent through chemical bonds, and can effectively improve the performance of the glass fiber. For example, the coupling agent of the present application can be selected from γ-methacryloxypropyl trimethoxysilane coupling agent. At the same time, the amount of coupling agent needs to be controlled within a suitable range. It is found that if the content of the coupling agent is too low, it cannot effectively bridge between inorganic glass fiber and organic polymer film-forming agent; if the content is too high, it will hinder the film-forming agent from playing its due role. Therefore, the solid mass percentage of the coupling agent in the total solid mass of the infiltration agent is controlled to be 9.5% to 15.0%; preferably 10.0 to 14.5%; more preferably 10.5 to 14.0%.

[0021] The film-forming agent is the main component of the glass fiber infiltration agent, which has the functions of protecting the glass fiber, improving the cuttability, bunching and compatibility of the glass fiber with the matrix resin, and has a decisive influence on the continuous production and subsequent application of the glass fiber. Therefore, the selection of the film-forming agent is one of the focuses of the present application. At the same time, the amount of film-forming agent needs to be controlled within a suitable range; if the amount of film-forming agent is too small, the glass fiber is easily damaged by mechanical friction to produce hair, and the compatibility with the matrix resin is reduced; if the amount is too large, the resin of the yarn will be soaked slowly, causing the yarn to be soaked in the sheet material. Therefore, the solid mass percentage of the film-forming agent in the total solid mass of the infiltration agent is controlled to be 36.0% to 59.0%, preferably 40.0% to 57.0%, and more preferably 44.0% to 55.0%.

[0022] The film-forming agent used in the present application is in the form of an emulsion, specifically a combination of a first film-forming agent and a second film-forming agent. The first film-forming agent is a double crosslinking monomer modified PVAc emulsion, which is prepared by using vinyl acetate and vinyl versatate as the main monomers, diallyl phthalate (DAP) as the pre-crosslinking monomer, and vinyl triethoxy silane (VTES) as the post-crosslinking monomer, by using a semi-continuous seed emulsion polymerization method (reference: Synthesis and Performance of Double Crosslinking Monomer Modified PVAc Emulsion Adhesive [J]. Renjie, et al. China Adhesives. 2022 (31)). Compared with ordinary PVAc emulsion, the double crosslinking monomer modified PVAc emulsion has higher crosslinking degree, better water resistance and heat resistance, and when coated on the surface of glass fibers, it makes the glass fibers have better bundling, so that the integrity of the glass fibers can be maintained as much as possible during use, thereby reducing the hairiness. Preferably, the solid content of the double crosslinking monomer modified PVAc emulsion is 28.0% to 48.0%.

[0023] The second film-forming agent of the present application is a polyester modified epoxy emulsion, which is prepared by using an unsaturated polyester containing carboxyl end groups as an emulsifier to emulsify an epoxy resin, and the mass ratio of the unsaturated polyester to the epoxy resin is controlled to be 1:4 to 1:9. After the polyester modified epoxy emulsion is coated on the glass fibers, the epoxy component in it can ensure that the glass fibers have good bundling, reduce the generation of loose fibers during use, and further accumulate into hairiness; at the same time, it has good compatibility with the target reinforcing matrix, i.e. unsaturated resin, and can effectively improve the mechanical properties of glass fiber composite products. Preferably, the epoxy resin is at least one of bisphenol A type epoxy resin, bisphenol S type epoxy resin and bisphenol F type epoxy resin; further preferably, the epoxy equivalent weight of the epoxy resin is 700 to 3600 g / eq.

[0024] In addition, the present application needs to control the amount ratio of the first film-forming agent and the second film-forming agent. It has been found that when the mass ratio of the first film-forming agent to the second film-forming agent is controlled to be 1:1 to 1:3.5, the yarn has good bundling, less hairiness, high stiffness, good compatibility with unsaturated resin, and high mechanical strength of the product. When the proportion of the first film-forming agent is too high, it is easy to cause slow resin penetration of the glass fiber product and decrease the mechanical properties of the product; when the proportion of the second film-forming agent is too high, it is easy to cause increase of the brittleness of the glass fiber product, damage of the film formation, and obvious decrease of the stiffness during use. Preferably, the mass ratio of the first film-forming agent to the second film-forming agent is 1:1.2 to 1:3.4; further preferably, it is 1:1.4 to 1:3.2.

[0025] Toughening agent refers to a substance that can increase the flexibility of the film layer of the film-forming agent. The film-forming agent of the thermosetting resin emulsion, such as the epoxy emulsion and the PVAc emulsion, has a large brittleness after being cured, and when the bonded part of the glass fiber bears an external force, cracks are easily generated and quickly spread, resulting in cracking of the film layer, thereby generating a large amount of glass fiber hair. Therefore, the present application uses a toughening agent to reduce the brittleness of the film layer, increase the toughness, and improve the strength of the glass fiber film layer against external force, thereby reducing the hair generated by the glass fiber during use. Preferably, the toughening agent is selected from an organic silicon modified water-based polyurethane emulsion, which is a product dispersed in water after reaction of toluene diisocyanate, hydroxyl-terminated polydimethylsiloxane and polyisopropylene glycol (reference: Preparation and Performance Research of High Content Organic Silicon Modified Water-based Polyurethane Emulsion [J]. Huang Qian, et al. Coatings Industry. 2006 (9)).

[0026] At the same time, the amount of the toughening agent also needs to be controlled within a suitable range. Too much amount will cause the film-forming agent system to be destroyed, and too little amount will cause the problem of too much glass fiber hair. Therefore, the present application controls the percentage of the solid mass of the toughening agent in the total solid mass of the sizing agent to be 8.5-21.0%, preferably 11.0-18.0%, and further preferably 12.5-15.5%.

[0027] In the present application, the lubricant is mainly used to ensure the lubricating effect of the glass fiber during the processes of drawing, winding and SMC production and use. Preferably, the lubricant is a composition of oleic acid diethanolamide and tall oil diethanolamide mixed in any ratio. At the same time, the amount of the lubricant also needs to be controlled within a suitable range. Too little amount cannot achieve the lubricating effect, and too much amount will cause the glass fiber surface to be sticky and affect the cutting dispersibility of the glass fiber, which has a negative impact on the mechanical properties of the glass fiber composite material. Therefore, the present application controls the percentage of the solid mass of the lubricant in the total solid mass of the sizing agent to be 9.0-20.0%, preferably 10.5-19.5%, and further preferably 12.0-19.0%.

[0028] Since the glass fiber is extremely prone to static electricity during the cutting process, which causes uneven dispersion, the present application uses an antistatic agent to improve the antistatic performance of the glass fiber. Preferably, the antistatic agent is selected from inorganic salts containing lithium, and further preferably lithium nitrate. At the same time, the amount of the antistatic agent also needs to be controlled within a suitable range. Too much amount will cause the film-forming agent system to be destroyed, and too little amount will cause the problem of static electricity of the glass fiber. Therefore, the present application controls the percentage of the solid mass of the antistatic agent in the total solid mass of the sizing agent to be 7.0-12.0%, preferably 7.5-11.5%, and further preferably 8.0-11.0%.

[0029] The water in the present application is the dispersion phase of the components in the sizing agent. The water is preferably deionized water.

[0030] According to a second aspect of the present application, a method for preparing the aforementioned glass fiber sizing agent for SMC is provided, comprising the following steps:

[0031] S1: dispersing a coupling agent in 10-50 times its volume of water to prepare a coupling agent solution;

[0032] S2: separately dissolving a lubricant and an antistatic agent in 10-40 times their volume of water to prepare a lubricant solution and an antistatic agent solution, respectively, and then mixing the two solutions and adding them to the solution obtained in step S1;

[0033] S3: diluting a first film-forming agent with 5-11 times its volume of water, and then adding a second film-forming agent, which has been diluted with 4-10 times its volume of water, to the solution obtained in step S2, mixing and stirring to homogeneity;

[0034] S4: dissolving a toughening agent in 5-15 times its volume of water, and then adding it to the solution obtained in step S3, mixing and stirring to homogeneity.

[0035] According to a third aspect of the present application, a glass fiber product coated with the aforementioned glass fiber sizing agent for SMC is provided.

[0036] According to a fourth aspect of the present application, the aforementioned glass fiber product is provided for use in the fields of automobiles and construction.

[0037] The glass fiber reinforced resin matrix coated with the aforementioned glass fiber sizing agent for SMC is an unsaturated polyester resin.

[0038] The glass fiber yarn coated with the aforementioned sizing agent has good surface smoothness and wear resistance, and the fiber is less likely to generate fiber fluff during production and use. In addition, the sizing agent has good compatibility with polyester resin, strong interfacial bonding, and can significantly improve the mechanical properties of the product. DETAILED DESCRIPTION

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be described below in connection with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other arbitrarily without conflict. The following are examples of preferred value ranges of each component included in the glass fiber composition according to the present application.

[0040] Preferred Example One

[0041] The glass fiber sizing agent for SMC according to the present application comprises effective components and water, and the solid content of the sizing agent is 3.6% to 12.6%; the effective components comprise a coupling agent, a film forming agent, a toughening agent, a lubricant and an antistatic agent; the percentage of the solid mass of each effective component of the sizing agent in the total mass of the sizing agent is shown as follows:

[0042]

[0043] The toughening agent is a silicone-modified waterborne polyurethane emulsion.

[0044] The film forming agent is a mixture of a first film forming agent and a second film forming agent; the first film forming agent is a double crosslinking monomer modified PVAc emulsion; the second film forming agent is a polyester modified epoxy emulsion; the mass ratio of the first film forming agent to the second film forming agent is 1:1 to 1:3.5.

[0045] Preferred Example Two

[0046] The glass fiber sizing agent for SMC according to the present application comprises effective components and water, and the solid content of the sizing agent is 4.1% to 12.1%; the percentage of the solid mass of each effective component of the sizing agent in the total mass of the sizing agent is shown as follows:

[0047]

[0048]

[0049] The toughening agent is a silicone-modified waterborne polyurethane emulsion.

[0050] The film forming agent is a mixture of a first film forming agent and a second film forming agent; the first film forming agent is a double crosslinking monomer modified PVAc emulsion; the second film forming agent is a polyester modified epoxy emulsion; the mass ratio of the first film forming agent to the second film forming agent is 1:1.2 to 1:3.4.

[0051] Preferred Example Three

[0052] The glass fiber sizing agent for SMC according to the present application comprises effective components and water, and the solid content of the sizing agent is 4.1% to 12.1%; the percentage of the solid mass of each effective component of the sizing agent in the total mass of the sizing agent is shown as follows:

[0053]

[0054] The toughening agent is a silicone-modified waterborne polyurethane emulsion.

[0055] The film forming agent is a mixture of a first film forming agent and a second film forming agent; the first film forming agent is a double crosslinking monomer modified PVAc emulsion; the second film forming agent is a polyester modified epoxy emulsion; and the mass ratio of the first film forming agent to the second film forming agent is 1:1.2-1:3.4.

[0056] The lubricant is a composition of oleic acid diethanolamide and tall oil diethanolamide mixed in any ratio.

[0057] Preferred Example Four

[0058] The glass fiber sizing agent for SMC according to the present application comprises effective components and water, and the solid content of the sizing agent is 4.1-12.1%; wherein the percentage of the solid mass of each component of the effective components in the total solid mass of the sizing agent is represented as follows:

[0059]

[0060]

[0061] The toughening agent is an organic silicon modified waterborne polyurethane emulsion.

[0062] The film forming agent is a mixture of a first film forming agent and a second film forming agent; the first film forming agent is a double crosslinking monomer modified PVAc emulsion; the second film forming agent is a polyester modified epoxy emulsion; and the mass ratio of the first film forming agent to the second film forming agent is 1:1.2-1:3.4.

[0063] The lubricant is a composition of oleic acid diethanolamide and tall oil diethanolamide mixed in any ratio.

[0064] The coupling agent is a silane coupling agent containing a methacryloyloxy group.

[0065] Preferred Example Five

[0066] The glass fiber sizing agent for SMC according to the present application comprises effective components and water, and the solid content of the sizing agent is 4.6-11.6%; wherein the percentage of the solid mass of each component of the effective components in the total solid mass of the sizing agent is represented as follows:

[0067]

[0068] The toughening agent is an organic silicon modified waterborne polyurethane emulsion.

[0069] The film-forming agent is a mixture of a first film-forming agent and a second film-forming agent; the first film-forming agent is a double crosslinking monomer modified PVAc emulsion; the second film-forming agent is a polyester modified epoxy emulsion; the mass ratio of the first film-forming agent and the second film-forming agent is 1:1.4-1:3.2.

[0070] Preferred example six

[0071] The glass fiber sizing agent for SMC according to the present application comprises effective components and water, and the solid content of the sizing agent is 4.6-11.6%; wherein the percentage of the solid mass of each component of the effective components in the total mass of the sizing agent is expressed as follows:

[0072]

[0073] The toughening agent is an organic silicon modified waterborne polyurethane emulsion.

[0074] The film-forming agent is a mixture of a first film-forming agent and a second film-forming agent; the first film-forming agent is a double crosslinking monomer modified PVAc emulsion; the second film-forming agent is a polyester modified epoxy emulsion; the mass ratio of the first film-forming agent and the second film-forming agent is 1:1.4-1:3.2.

[0075] The antistatic agent is a lithium-containing inorganic salt.

[0076] The organic silicon modified waterborne polyurethane emulsion is prepared by dispersing the product of the reaction of toluene diisocyanate, hydroxyl-terminated polydimethylsiloxane and polyisopropylene glycol in water with dimethylol propionic acid as a chain extender.

[0077] Preferred example seven

[0078] The glass fiber sizing agent for SMC according to the present application comprises effective components and water, and the solid content of the sizing agent is 4.6-11.6%; wherein the percentage of the solid mass of each component of the effective components in the total mass of the sizing agent is expressed as follows:

[0079]

[0080] The toughening agent is an organic silicon modified waterborne polyurethane emulsion.

[0081] The film-forming agent is a mixture of a first film-forming agent and a second film-forming agent; the first film-forming agent is a double crosslinking monomer modified PVAc emulsion; the second film-forming agent is a polyester modified epoxy emulsion; the mass ratio of the first film-forming agent and the second film-forming agent is 1:1.4-1:3.2.

[0082] The antistatic agent is a lithium-containing inorganic salt.

[0083] The organic silicon modified waterborne polyurethane emulsion is prepared by dispersing the reaction product of toluene diisocyanate, hydroxyl-terminated polydimethylsiloxane and polyisopropylene glycol in water with dimethylol propionic acid as a chain extender.

[0084] The double crosslinking monomer modified PVAc emulsion is prepared by using semi-continuous seed emulsion polymerization method with diallyl phthalate as a pre-crosslinking monomer and vinyl triethoxysilane as a post-crosslinking monomer.

[0085] Preferred Example Eight

[0086] The glass fiber sizing agent for ultra-low hairiness SMC according to the present application comprises effective components and water, and the solid content of the sizing agent is 4.6-11.6%; wherein the solid mass percentage of each component of the effective components in the total solid mass of the sizing agent is expressed as follows:

[0087]

[0088] The toughening agent is an organic silicon modified waterborne polyurethane emulsion.

[0089] The film forming agent is a mixture of a first film forming agent and a second film forming agent; the first film forming agent is a double crosslinking monomer modified PVAc emulsion; the second film forming agent is a polyester modified epoxy emulsion; and the mass ratio of the first film forming agent to the second film forming agent is 1:1.4-1:3.2.

[0090] The antistatic agent is an inorganic salt containing lithium.

[0091] The organic silicon modified waterborne polyurethane emulsion is prepared by dispersing the reaction product of toluene diisocyanate, hydroxyl-terminated polydimethylsiloxane and polyisopropylene glycol in water with dimethylol propionic acid as a chain extender.

[0092] The double crosslinking monomer modified PVAc emulsion is prepared by using semi-continuous seed emulsion polymerization method with diallyl phthalate as a pre-crosslinking monomer and vinyl triethoxysilane as a post-crosslinking monomer.

[0093] The polyester modified epoxy emulsion is prepared by emulsifying an epoxy resin with an unsaturated polyester as an emulsifier; the epoxy resin is at least one of bisphenol A type epoxy resin, bisphenol S type epoxy resin and bisphenol F type epoxy resin; and the epoxy equivalent weight of the epoxy resin is 700-3600 g / eq.

[0094] The beneficial effects of the SMC glass fiber sizing agent according to the present application with the above content ranges of each component will be illustrated by specific experimental data in the examples. Some specific embodiments of the SMC glass fiber sizing agent according to the present application are listed as follows.

[0095] Examples

[0096] The solid mass percentage of each component in the embodiments of the glass fiber sizing agent for SMC of the present application is shown in Table 1.

[0097] Table 1 Formulation of the glass fiber sizing agent for SMC of the embodiments

[0098]

[0099] Table 1 (continued) Formulation of the glass fiber sizing agent for SMC of the embodiments

[0100]

[0101]

[0102] The preparation method of Examples 1-12 is as follows:

[0103] S1: The coupling agent is pre-dispersed in 10-50 times its volume of water to obtain a coupling agent solution;

[0104] S2: The lubricant and the antistatic agent are separately pre-dissolved in 10-40 times their volume of water to obtain a lubricant solution and an antistatic agent solution, respectively, and then the two solutions are mixed and added to the solution obtained in step S1;

[0105] S3: The first film-forming agent is diluted with 5-11 times its volume of water, and the second film-forming agent is diluted with 4-10 times its volume of water, and then added to the solution obtained in step S2 in sequence, mixed and stirred uniformly;

[0106] S4: The toughening agent is pre-dissolved in 5-15 times its volume of water and then added to the solution obtained in step S3, mixed and stirred uniformly.

[0107] In order to further illustrate the beneficial effects of the present application, two commonly used glass fiber sizing agents (Comparative Example 1 and Comparative Example 2) are selected, and the solid content percentage of each effective component in the comparative examples is expressed as follows: the balance is water:

[0108] Comparative Example 1

[0109]

[0110] Comparative Example 2

[0111]

[0112] Comparative Example 3

[0113]

[0114] Comparative Example 3

[0115] Table 2 shows the performance test results of the glass fiber ply yarn products produced with the sizing agents of Examples 1-12 and Comparative Examples 1-2. In order to ensure the comparability of the test results, the glass fiber combustible content prepared in each example and comparative example was ensured to be substantially the same (control range 1.3-1.6, center value 1.45) during the sample preparation, i.e., the solid mass of the sizing agent coated on the surface of the glass fiber accounted for a percentage of the mass of the glass fiber in each example and comparative example was substantially the same. In addition, the other raw materials and production process parameters used when performing the mechanical property tests of the glass fiber prepared in each example and comparative example were kept the same, so as to parallelly compare the properties of the glass fiber.

[0116] Table 2 Glass fiber performance test results

[0117]

[0118]

[0119] Table 2 (continued) Glass fiber performance test results

[0120]

[0121] Note:

[0122] Among them, the glass fiber reinforced unsaturated polyester resin sample for mechanical property (including bending strength and side pressure strength) test was prepared by SMC (sheet molding compound) molding.

[0123] From the test results of the above examples, we can see that the hairiness test results of the glass fiber coated with the sizing agent of the present application have obvious advantages compared with the comparative examples, and the mechanical properties of the fiber reinforced unsaturated polyester resin prepared are also obviously better than those of the comparative examples, such as the glass fiber prepared with the sizing agent of Examples 6 and 7, which are particularly outstanding. In addition, it also has the advantages of high stiffness and good surface smoothness.

[0124] Therefore, the glass fiber sizing agent formula and process provided by the present application are scientific and reasonable, the glass fiber coated with the sizing agent has better compatibility with the unsaturated polyester resin, can form a stronger interfacial bond, and at the same time, the surface performance of the product is also improved.

[0125] The above-described content can be implemented alone or in various combinations, and these variations are within the protection scope of the present application.

[0126] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalent ones, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A glass fiber sizing for SMC, characterized in that, The infiltrant comprises effective components and water; the solid content of the infiltrant is 3.6%-12.6%; the effective components comprise coupling agent, film forming agent, toughening agent, lubricant and antistatic agent; the percentage of the solid mass of each effective component of the infiltrant in the total mass of the solid of the infiltrant is shown as follows: Coupling agent 9.5-15.0%; Film forming agent 36.0-59.0%; Toughening agent 8.5-21.0%; Lubricant 9.0-20.0%; Antistatic agent 7.0-12.0%; The toughening agent is organic silicon modified water-based polyurethane emulsion. The film forming agent is a mixture of first film forming agent and second film forming agent; the first film forming agent is double crosslinking monomer modified PVAc emulsion; the second film forming agent is polyester modified epoxy emulsion; the mass ratio of the first film forming agent and the second film forming agent is 1:1-1:3.5; The lubricant is a composition of oleic acid diethanol amide and tall oil diethanol amide mixed in any ratio; The antistatic agent is inorganic salt containing lithium.

2. The glass fiber sizing for SMC according to claim 1, characterized in that, The percentage of the solid mass of each effective component of the infiltrant in the total mass of the solid of the infiltrant is shown as follows: Coupling agent 10.0-14.5%; Film forming agent 40.0-57.0%; Toughening agent 11.0-18.0%; Lubricant 10.5-19.5%; Antistatic agent 7.5-11.5%.

3. The glass fiber sizing for SMC according to claim 1 or 2, characterized in that, The coupling agent is silane coupling agent containing methacryloyloxy group.

4. The glass fiber sizing for SMC according to claim 1 or 2, characterized in that, The organic silicon modified water-based polyurethane emulsion is prepared by dispersing the product of reaction of toluene diisocyanate, hydroxyl-terminated polydimethylsiloxane and polyisopropylene glycol in water with dimethylol propionic acid as chain extender.

5. The glass fiber sizing for SMC according to claim 1 or 2, characterized in that, The double crosslinking monomer modified PVAc emulsion is prepared by semi-continuous seed emulsion polymerization method with diallyl phthalate as pre-crosslinking monomer and vinyl triethoxy silane as post-crosslinking monomer.

6. The glass fiber sizing for SMC according to claim 1 or 2, characterized in that, The polyester modified epoxy emulsion is prepared by emulsifying epoxy resin with unsaturated polyester as emulsifier; the epoxy resin is at least one of bisphenol A type epoxy resin, bisphenol S type epoxy resin and bisphenol F type epoxy resin; the epoxy equivalent weight of the epoxy resin is 700-3600 g / eq.

7. A method of producing a glass fiber sizing agent for SMC according to any one of claims 1 to 6, characterized by, The method comprises the following steps: S1: coupling agent is pre-dispersed in water 10-50 times of its volume to prepare coupling agent solution; S2: lubricant and antistatic agent are respectively pre-dissolved in water 10-40 times of its volume to prepare lubricant solution and antistatic agent solution respectively, then the two solutions are mixed uniformly and added into the solution obtained in step S1; S3: first film forming agent is diluted with water 5-11 times of its volume; second film forming agent is diluted with water 4-10 times of its volume, then they are added into the solution obtained in step S2 in sequence and mixed and stirred uniformly; S4: toughening agent is pre-dissolved in water 5-15 times of its volume and then added into the solution obtained in step S3, and mixed and stirred uniformly.

8. A glass fiber product produced by coating the glass fiber infiltrant for SMC according to any one of claims 1-6.

9. Use of the glass fiber product according to claim 8 in the fields of automobile and building.

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