A glass fiber sizing agent for coloring grade SMC and its preparation method, product and application

Abstract

This application discloses a glass fiber sizing for pigmented SMC, comprising active ingredients and water. The sizing has a solid content of 3.8% to 13.8%. The percentage of the solid mass of each active ingredient relative to the total solid mass of the sizing is expressed as follows: coupling agent 9.0% to 20%, film-forming agent 36% to 72%, antistatic agent 3.0% to 9.0%, leveling agent 4.0% to 11%, and feel agent 12% to 27%. The feel agent is a polymer polymerized from a silicone oil containing a long-chain alkyl group and modified by end capping. The film-forming agent is a mixture of a first film-forming agent and a second film-forming agent in a mass ratio of 1:1 to 1:5, wherein the first film-forming agent is a silicone-modified epoxy emulsion, and the second film-forming agent is a fast-permeating unsaturated polyester emulsion. The glass fiber yarn produced by coating with the sizing has a smooth surface and good molding fluidity, ensuring uniform fiber dispersion in the finished product and preventing surface glass fiber grain. The sizing also exhibits good compatibility with polyester resin and strong interfacial bonding, significantly improving the mechanical properties of the finished product.

Description

Technical Field

[0001] The present application relates to the technical field of sizing agents for glass fiber coating, and in particular to a glass fiber sizing agent for coloring grade SMC, as well as a preparation method, product and application of the sizing agent. Background Art

[0002] SMC products, with their numerous advantages, including lightweight, high strength, corrosion resistance, designability, ease of molding, and coloring, are finding increasing application in the construction industry. For example, applications in electrical installations include electrical cabinets and instrument boxes, while residential applications primarily include waterproofing panels, door panels, and water tanks. These applications require products with a high appearance quality while maintaining a certain level of strength. These products are typically light-colored and do not undergo secondary coating. Therefore, the glass fiber must exhibit excellent coloring properties to ensure a high-quality appearance, without noticeable fiber grain. At the same time, it must bond well with the unsaturated resin matrix to ensure good mechanical properties.

[0003] With the continuous improvement of SMC technology and living standards, downstream customers are placing more stringent demands on the mechanical properties, appearance quality, and various special properties of products in this field. For example, the structural and integrated design of electrical cabinets requires higher component strength, and the design of waterproof panels is more aesthetically pleasing, requiring better product appearance quality to achieve its advantages. These developments are placing higher and multi-dimensional demands on the performance of colored glass fiber. Colored glass fiber refers to glass fiber reinforced resin composites that are less likely to show their original color, meaning that the surface is less likely to produce noticeable glass fiber grain. Summary of the Invention

[0004] The technical problem to be solved by the present application is to provide a glass fiber sizing for colored grade SMC. The glass fiber produced by coating the sizing has a smooth surface and good molding fluidity, so that the fiber is evenly dispersed in the product and is not prone to surface glass fiber grain. The sizing also has good compatibility with polyester resin and strong interface bonding, thereby significantly improving the mechanical properties of the product. At the same time, the glass fiber also has the advantages of good cutting dispersion and less hairiness during production and use.

[0005] In order to achieve the above technical effects, this application is implemented through the following technical solutions:

[0006] According to one aspect of the present application, a glass fiber sizing for colored SMC is provided, comprising effective components and water; the solid content of the sizing is 3.8 to 13.8%; the effective components comprise a coupling agent, a film-forming agent, an antistatic agent, a leveling agent, and a feel agent; the percentage of the solid mass of each effective component of the sizing to the total solid mass of the sizing is expressed as follows:

[0007]

[0008] The hand feeling agent is a high molecular polymer formed by polymerization of silicone oil containing long-chain alkyl groups and end-capping modification;

[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 silicone-modified epoxy emulsion, and the second film-forming agent is a fast-penetrating unsaturated polyester emulsion; the mass ratio of the first film-forming agent to the second film-forming agent is 1:1 to 1:5.

[0010] The percentage of the solid mass of each effective component of the wetting agent to the total solid mass of the wetting agent is expressed as follows:

[0011]

[0012] Wherein, the coupling agent is a silane coupling agent containing an unsaturated bond.

[0013] Wherein, the leveling agent is a polyether-modified organic silicon compound.

[0014] Wherein, the antistatic agent is at least one of sodium dodecyl sulfonate, lithium dodecyl sulfonate and potassium dodecyl sulfonate.

[0015] The organosilicon-modified epoxy emulsion is obtained by mixing epoxy-terminated polyether organosilicon as an emulsifier with epoxy resin and then uniformly dispersing the mixture in water.

[0016] The epoxy resin is at least one of bisphenol A epoxy resin, bisphenol S epoxy resin and bisphenol F epoxy resin; and the epoxy equivalent of the epoxy resin is 600 to 3300 g / eq.

[0017] The fast-penetrating unsaturated polyester emulsion is obtained by polycondensing maleic anhydride doped with phthalic anhydride and propylene glycol, and the product is uniformly dispersed in water; the molecular weight of the fast-penetrating unsaturated polyester is 4000-15000 Da.

[0018] The functions and contents of the components in the glass sizing agent for colored SMC in this application are as follows:

[0019] The coupling agent of the present application is a silane coupling agent (with the general structural formula YSiX3). In the general structural formula, Y is an organic end, usually a chain olefin or a hydrocarbon group with functional groups such as amino, thiol, epoxy, azide and isocyanate at the end; X is a hydrolyzable group, such as chlorine, alkoxy, etc. Due to this special chemical structure, the silane coupling agent can be used as a bridge between the inorganic glass fiber and the organic polymer film-forming agent, so that the entire sizing film can be fixed to the surface of the glass fiber through chemical bonds, thereby maintaining the good bundling, toughness and stiffness of the glass fiber during processing or cutting. Preferably, the coupling agent of the present application is a silane coupling agent containing an unsaturated bond. More preferably, the coupling agent of the present application is a silane coupling agent containing a double bond. The coupling agent contains a double bond and can form a stable bond with the film-forming agent selected in the present application through a chemical bond, which can effectively improve the performance of the glass fiber. Exemplarily, the coupling agent of the present application can use a vinyltrimethoxysilane coupling agent. At the same time, the amount of coupling agent must be controlled within an appropriate range. Studies have found that if the coupling agent content is too low, it will not be able to effectively bridge the gap between the inorganic glass fiber and the organic polymer film-forming agent; if the content is too high, it will interfere with the film-forming agent and prevent it from playing its due role. Therefore, the solid mass of the coupling agent in this application is controlled to be 9.0% to 20.0% of the total solid mass of the sizing agent; preferably 10.0% to 19.0%; and more preferably 11.0% to 18.0%.

[0020] The film-forming agent is the main component of the glass fiber sizing agent. It has the function of protecting the glass fiber, improving the cuttability and bundling of the glass fiber and its compatibility 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 this application. At the same time, the amount of the film-forming agent must be controlled within an appropriate range; if the amount of the film-forming agent is too little, the glass fiber will be easily damaged by mechanical friction to produce fuzz, and the compatibility with the matrix resin will be reduced; if the amount is too much, the yarn resin will be impregnated more slowly and it will not be easy to become a single fiber, resulting in more glass fiber grains in the product. Therefore, this application controls the percentage of the solid mass of the film-forming agent to the total solid mass of the sizing agent to be 36.0-72.0%, preferably 40.0-69.0%, and more preferably 44.0-66.0%.

[0021] The film-forming agent of the present application adopts a combination of a first film-forming agent and a second film-forming agent, and the film-forming agent used in the present application is in the form of an emulsion. Among them, the first film-forming agent is an organosilicon-modified epoxy emulsion, which is obtained by mixing end-epoxy polyether organosilicon with epoxy resin as an emulsifier and uniformly dispersing it in water (Reference: Preparation and Performance Study of Organosilicon-Modified Epoxy Resin Emulsion [J]. Peng Jun et al. New Chemical Materials. 2021 (12)). Compared with ordinary epoxy resin emulsions, organosilicon-modified epoxy emulsions have better toughness and heat resistance after film formation, so that the glass fiber can maintain its integrity as much as possible during use. Preferably, the epoxy resin is at least one of bisphenol A epoxy resin, bisphenol S epoxy resin and bisphenol F epoxy resin; further preferably, the epoxy equivalent of the epoxy resin is 600 to 3300 g / eq. The solid content of the organosilicon-modified epoxy emulsion described in the present application is 32% to 52%.

[0022] The second film-forming agent of the present application is a fast-penetrating unsaturated polyester emulsion, which is obtained by polycondensation reaction of maleic anhydride doped with phthalic anhydride and propylene glycol, and the product is uniformly dispersed in water. The specific preparation method is: add maleic anhydride doped with phthalic anhydride and propylene glycol into a four-necked bottle, the molar ratio of the two is 1:0.6 to 1:1.8, start the stirring program and heat up. When the temperature reaches 200-220°C, maintain the temperature for polycondensation reaction, and test the acid value between 15 and 30 to control the reaction end point; then cool the reaction product to room temperature, add emulsifier, and then add water to disperse at a speed of 2000-6000 rpm to prepare a fast-penetrating unsaturated polyester emulsion. Among them, the temperature is preferably 210°C; the emulsifier can be a conventional emulsifier system, preferably, a mixture of branched fatty alcohol polyoxyethylene ether, modified fatty alcohol polyoxyethylene and vinyl ether EO-PO block copolymer. The doping of phthalic anhydride can increase the hardness of polyester after film formation, maintain a high stiffness of glass fiber, and improve cuttability and molding fluidity. After the fast-penetrating unsaturated polyester emulsion forms a film, it can ensure that the glass fiber is quickly impregnated by the unsaturated resin, and has good compatibility, which can effectively improve the mechanical properties of the product. In addition, the surface impregnation agent of the glass fiber after impregnation can be well dissolved in the resin system, and the glass fiber can be in a monofilament state in the resin, resulting in fewer glass fiber grains in the product. Preferably, the molecular weight of the fast-penetrating unsaturated polyester emulsion is 4000~15000Da; the solid content of the fast-penetrating unsaturated polyester emulsion is 25%~35%.

[0023] In addition, this application needs to control the dosage relationship between the first film-forming agent and the second film-forming agent. Studies have found that when the mass ratio of the first film-forming agent to the second film-forming agent is controlled at 1:1 to 1:5, the yarn has better bundling, less hairiness, high stiffness, good compatibility with unsaturated resins, high mechanical strength of the product and less glass fiber grain on the surface. When the proportion of the first film-forming agent is too high, it is easy to cause the resin penetration of the glass fiber product to slow down, the mechanical properties of the product to decrease, and the surface glass fiber grain to increase; when the proportion of the second film-forming agent is too high, it is easy to cause the bundling of the glass fiber product to deteriorate, the hairiness to increase during product production and use, and the stiffness to decrease. Preferably, the mass ratio of the first film-forming agent to the second film-forming agent is 1:1.4 to 1:4.7; more preferably, it is 1:1.6 to 1:4.5.

[0024] Since glass fiber is very prone to static electricity during the cutting process, which causes uneven dispersion problems, the present application uses an antistatic agent to improve the antistatic properties of the glass fiber. Preferably, the antistatic agent is selected from at least one of sodium dodecyl sulfonate, lithium dodecyl sulfonate and potassium dodecyl sulfonate. At the same time, the amount of the antistatic agent must also be controlled within an appropriate range. Too much will cause the film-forming agent system to be destroyed, and too little will cause static electricity problems in the glass fiber. Therefore, the present application controls the solid mass of the antistatic agent to a percentage of 3.0 to 9.0% of the total solid mass of the impregnating agent, preferably 3.5 to 8.0%, and more preferably 4.0 to 7.5%.

[0025] The use of a leveling agent can effectively reduce the surface tension of the wetting agent, allowing the wetting agent to spread evenly on the surface of the glass fiber, reducing the occurrence of soft and hard segments in the glass fiber, and making the glass fiber have better fluidity during molding, more evenly distributed in the product, and helping to reduce the glass fiber grain on the surface. Preferably, the leveling agent described in the present application is a polyether-modified organosilicon compound. At the same time, the amount of the leveling agent must also be controlled within an appropriate range. Excessive use will cause the film-forming agent system to be destroyed, while too little will not have the effect of reducing the tension of the wetting agent. Therefore, the present application controls the solid mass of the leveling agent to a percentage of 4.0 to 11.0% of the total solid mass of the wetting agent; preferably 4.5 to 10.0%; and more preferably 5.0 to 9.5%.

[0026] The use of a feel agent can effectively reduce the bonding force between yarn bundles, thereby reducing the tension of the yarn being unwound from the original yarn tube during plying, and can minimize yarn wear, tearing, and frizz. It can also increase the smoothness of the finished glass fiber surface and reduce the generation of lint during use. Preferably, the feel agent described in this application is a polymer polymerized from silicone oil containing a long-chain alkyl group and end-capped and modified; the long-chain alkyl group is a saturated alkyl chain, and the number of carbon atoms can be 12, 14, 16, 18, or 20; the feel agent used in this application is a commercially available product (Shanghai Huiyan New Materials Co., Ltd., brand HY-51Z series). At the same time, the amount of the feel agent used must also be controlled within an appropriate range. Excessive use will destroy the film-forming structure of the film-forming agent, while too little will have no effect. Therefore, this application controls the solid mass of the feel agent to a percentage of 12.0-27.0% of the total solid mass of the sizing agent, preferably 13.0-26.0%, and more preferably 14.0-25.0%.

[0027] The water in this application is the dispersed phase of each component in the wetting agent. Wherein, water is preferably deionized water.

[0028] According to a second aspect of the present application, a method for preparing the aforementioned colored grade SMC glass fiber sizing is provided, comprising the following steps:

[0029] S1: Add the coupling agent and the feeling agent into water for pre-dispersion to prepare a coupling agent solution and a feeling agent solution respectively, and then mix the two solutions evenly;

[0030] S2: pre-dissolving the antistatic agent and adding it to the solution obtained in step S1;

[0031] S3: diluting the first film-forming agent with 6 to 12 times its volume of water; diluting the second film-forming agent with 3 to 9 times its volume of water, and adding the two to the solution obtained in step S2, mixing and stirring uniformly;

[0032] S4: pre-dissolve the leveling agent and add it to the solution obtained in step S3, mix and stir until evenly mixed.

[0033] According to a third aspect of the present application, a glass fiber product is provided, which is produced by coating the colored-grade SMC with a glass fiber sizing.

[0034] According to a fourth aspect of the present application, application of the glass fiber product in the construction field is provided.

[0035] The glass fiber reinforced resin matrix produced by coating the colored grade SMC with a glass fiber sizing agent is an unsaturated polyester resin.

[0036] The glass fiber produced by coating the sizing agent described in the present application has a smooth surface and good molding fluidity, so that the fibers are evenly dispersed in the product and are less likely to produce surface glass fiber grain; it also has good compatibility with unsaturated polyester resin and strong interface bonding, thereby significantly improving the mechanical properties of the product; at the same time, the glass fiber also has the advantages of good cutting dispersion and less hairiness during production and use.

[0037] The beneficial effects of selecting the above-mentioned content ranges of the components in the glass fiber sizing for the colored grade SMC of the present application will be illustrated by providing specific experimental data through examples.

[0038] The following are examples of preferred value ranges for the various components included in the glass fiber composition according to the present application.

[0039] Preferred Example 1

[0040] The glass fiber sizing agent for colored SMC according to the present application comprises an effective component and water, and the solid content of the sizing agent is 3.8 to 13.8%. The percentage of the solid mass of each component of the effective component to the total solid mass of the sizing agent is expressed as follows:

[0041]

[0042] The hand feeling agent is a high molecular polymer formed by polymerization of silicone oil containing long-chain alkyl groups and end-capping modification;

[0043] The film-forming agent is a mixture of a first film-forming agent and a second film-forming agent, wherein the first film-forming agent is a silicone-modified epoxy emulsion; the second film-forming agent is a fast-penetrating unsaturated polyester emulsion; and the mass ratio of the first film-forming agent to the second film-forming agent is 1:1 to 1:5.

[0044] Preferred Example 2

[0045] The glass fiber sizing agent for colored SMC according to the present application comprises an effective component and water, and the solid content of the sizing agent is 4.2 to 13.3%. The percentage of the solid mass of each component of the effective component to the total solid mass of the sizing agent is expressed as follows:

[0046]

[0047] The hand feeling agent is a high molecular polymer formed by polymerization of silicone oil containing long-chain alkyl groups and end-capping modification;

[0048] The film-forming agent is a mixture of a first film-forming agent and a second film-forming agent, wherein the first film-forming agent is a silicone-modified epoxy emulsion; the second film-forming agent is a fast-penetrating unsaturated polyester emulsion; and the mass ratio of the first film-forming agent to the second film-forming agent is 1:1.4 to 1:4.7.

[0049] Preferred Example 3

[0050] The glass fiber sizing agent for colored SMC according to the present application comprises an effective component and water, and the solid content of the sizing agent is 4.6-12.5%. The percentage of the solid mass of each component of the effective component to the total solid mass of the sizing agent is expressed as follows:

[0051]

[0052] Among them, the hand feeling agent is a high molecular polymer formed by the polymerization of silicone oil containing long-chain alkyl groups and end-capped modifications; 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 silicone-modified epoxy emulsion; the second film-forming agent is a fast-penetrating unsaturated polyester emulsion; the mass ratio of the first film-forming agent to the second film-forming agent is 1:1.6 to 1:4.5.

[0053] Wherein, the coupling agent is a silane coupling agent containing an unsaturated bond.

[0054] Preferred Example 4

[0055] The glass fiber sizing agent for colored SMC according to the present application comprises an effective component and water, and the solid content of the sizing agent is 4.2 to 13.3%. The percentage of the solid mass of each component of the effective component to the total solid mass of the sizing agent is expressed as follows:

[0056]

[0057] Among them, the hand feeling agent is a high molecular polymer formed by the polymerization of silicone oil containing long-chain alkyl groups and end-capped modifications; 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 silicone-modified epoxy emulsion; the second film-forming agent is a fast-penetrating unsaturated polyester emulsion; the mass ratio of the first film-forming agent to the second film-forming agent is 1:1.4 to 1:4.7.

[0058] Wherein, the coupling agent is a silane coupling agent containing an unsaturated bond; and the leveling agent is a polyether-modified organic silicon compound.

[0059] Preferred Example 5

[0060] The glass fiber sizing agent for colored SMC according to the present application comprises an effective component and water, and the solid content of the sizing agent is 4.6-12.5%. The percentage of the solid mass of each component of the effective component to the total solid mass of the sizing agent is expressed as follows:

[0061]

[0062] Among them, the hand feeling agent is a high molecular polymer formed by the polymerization of silicone oil containing long-chain alkyl groups and end-capped modifications; 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 silicone-modified epoxy emulsion; the second film-forming agent is a fast-penetrating unsaturated polyester emulsion; the mass ratio of the first film-forming agent to the second film-forming agent is 1:1.6 to 1:4.5.

[0063] Wherein, the coupling agent is a silane coupling agent containing a double bond; the leveling agent is a polyether-modified organic silicon compound; and the antistatic agent is at least one of sodium dodecyl sulfonate, lithium dodecyl sulfonate and potassium dodecyl sulfonate.

[0064] Preferred Example 6

[0065] The glass fiber sizing agent for colored SMC according to the present application comprises an effective component and water, and the solid content of the sizing agent is 5.0-12%. The percentage of the solid mass of each component of the effective component to the total solid mass of the sizing agent is expressed as follows:

[0066]

[0067] The hand-feeling agent is a polymer formed by polymerizing a silicone oil containing a long-chain alkyl group and modified by end capping. The film-forming agent is a mixture of a first film-forming agent and a second film-forming agent, wherein the first film-forming agent is a silicone-modified epoxy emulsion and the second film-forming agent is a fast-penetrating unsaturated polyester emulsion. The mass ratio of the first film-forming agent to the second film-forming agent is 1:2.0 to 1:3.8. The coupling agent is a silane coupling agent containing a double bond. The leveling agent is a polyether-modified silicone compound. The antistatic agent is at least one of sodium dodecyl sulfonate, lithium dodecyl sulfonate, and potassium dodecyl sulfonate.

[0068] Preferred Example 7

[0069] The glass fiber sizing agent for colored SMC according to the present application comprises an effective component and water, and the solid content of the sizing agent is 5.0-12%. The percentage of the solid mass of each component of the effective component to the total solid mass of the sizing agent is expressed as follows:

[0070]

[0071] Among them, the hand feeling agent is a high molecular polymer formed by the polymerization of silicone oil containing long-chain alkyl groups and end-capped modifications; 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 silicone-modified epoxy emulsion; the second film-forming agent is a fast-penetrating unsaturated polyester emulsion; the mass ratio of the first film-forming agent to the second film-forming agent is 1:2.0 to 1:3.8.

[0072] The silicone-modified epoxy emulsion is obtained by mixing epoxy-terminated polyether silicone as an emulsifier with an epoxy resin and then uniformly dispersing the mixture in water; the epoxy resin is at least one of bisphenol A epoxy resin, bisphenol S epoxy resin and bisphenol F epoxy resin; and the epoxy equivalent of the epoxy resin is 600 to 3300 g / eq.

[0073] The fast-penetrating unsaturated polyester emulsion is obtained by polycondensing maleic anhydride doped with phthalic anhydride and propylene glycol, and the product is uniformly dispersed in water; the molecular weight of the fast-penetrating unsaturated polyester is 4000-15000 Da.

[0074] Preferred Example 8

[0075] The glass fiber sizing agent for colored SMC according to the present application comprises an effective component and water, and the solid content of the sizing agent is 5.0-12%. The percentage of the solid mass of each component of the effective component to the total solid mass of the sizing agent is expressed as follows:

[0076]

[0077] Among them, the hand feeling agent is a high molecular polymer formed by the polymerization of silicone oil containing long-chain alkyl groups and end-capped modifications; 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 silicone-modified epoxy emulsion; the second film-forming agent is a fast-penetrating unsaturated polyester emulsion; the mass ratio of the first film-forming agent to the second film-forming agent is 1:2.0 to 1:3.8.

[0078] Wherein, the coupling agent is a silane coupling agent containing a double bond; the leveling agent is a polyether-modified organic silicon compound; and the antistatic agent is at least one of sodium dodecyl sulfonate, lithium dodecyl sulfonate and potassium dodecyl sulfonate.

[0079] The silicone-modified epoxy emulsion is obtained by mixing an epoxy-terminated polyether silicone as an emulsifier with an epoxy resin and then uniformly dispersing the mixture in water. The epoxy resin is at least one of bisphenol A, bisphenol S, and bisphenol F, and has an epoxy equivalent weight of 600 to 3300 g / eq. The fast-penetrating unsaturated polyester emulsion is obtained by polycondensing maleic anhydride doped with phthalic anhydride and propylene glycol, with the product uniformly dispersed in water. The molecular weight of the fast-penetrating unsaturated polyester is 4000 to 15000 Da. DETAILED DESCRIPTION

[0080] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with the specific embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other in any way.

[0081] Some specific examples of the glass fiber sizing for SMC of this application are listed below.

[0082] Example

[0083] The percentage of the solid mass of each component in the embodiment of the colored grade SMC glass fiber sizing of the present application to the total solid mass is shown in Table 1.

[0084] Table 1 Example formula of glass fiber sizing agent for colored SMC

[0085]

[0086] Table 1 (Continued) Example formula of glass fiber sizing agent for colored SMC

[0087]

[0088] The preparation methods of Examples 1 to 12 are as follows:

[0089] S1: Add the coupling agent and the feeling agent into water for pre-dispersion to prepare a coupling agent solution and a feeling agent solution respectively, and then mix the two solutions evenly;

[0090] S2: pre-dissolving the antistatic agent and adding it to the solution obtained in step S1;

[0091] S3: diluting the first film-forming agent with 6 to 12 times its volume of water; diluting the second film-forming agent with 3 to 9 times its volume of water, and adding the two to the solution obtained in step S2, mixing and stirring uniformly;

[0092] S4: pre-dissolve the leveling agent and add it to the solution obtained in step S3, mix and stir evenly to obtain the wetting agent.

[0093] 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) and sizing agents with different content ratios are selected as comparative examples (Comparative Example 3 and Comparative Example 4). Among them, the feeling agents of Comparative Examples 3-4 are the same as those of the present application. The percentage of the solid content of each effective component in Comparative Examples 1 to 4 to the total solid content of the sizing agent is expressed as follows, with the balance being water:

[0094] Comparative Example 1

[0095]

[0096] Comparative Example 2

[0097]

[0098] Comparative Example 3

[0099]

[0100]

[0101] Comparative Example 4

[0102]

[0103] Table 2 shows the performance test results of glass fiber plied yarn products produced using the sizing agents described in Examples 1 to 12 and Comparative Examples 1 to 4. To ensure comparability of the test results, the combustible content of the glass fibers prepared in each Example and Comparative Example was ensured to be substantially the same during sample preparation (control range 1.15 to 1.35, center value 1.25). That is, the percentage of the solid mass of the sizing applied to the surface of the glass fibers as a percentage of the mass of the glass fibers in the Examples and Comparative Examples was substantially the same. In addition, the other raw materials and production process parameters used in the mechanical property tests of the glass fibers prepared in each Example and Comparative Example were ensured to be consistent, allowing for parallel comparison of the performance of the glass fibers.

[0104] Table 2 Performance test results of glass fibers produced by coating with the sizing agent in the examples and comparative examples

[0105]

[0106]

[0107] Table 2 (Continued) Performance test results of glass fibers produced by coating with the sizing agents described in Examples and Comparative Examples

[0108]

[0109] Note:

[0110] Among them, the glass fiber reinforced unsaturated polyester resin sample used for mechanical properties (including bending strength and lateral compressive strength) testing was prepared by SMC (sheet molding compound) molding.

[0111] From the test results of the above embodiments, we can see that the glass fiber surface texture of the glass fiber products coated with the wetting agent of the present application has obvious advantages, and the mechanical properties of the prepared fiber-reinforced unsaturated polyester resin are also significantly better than those of the comparative examples. For example, the glass fibers prepared with the wetting agents of Examples 6 and 7 perform particularly well. In addition, they also have the advantages of high stiffness, good surface smoothness, and less hairiness during production and use.

[0112] It can be seen from this that the glass fiber sizing agent formula and process provided in this 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 interface bond, and the surface performance of the product is also improved.

[0113] Finally, it should be noted that in this document, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0114] The above embodiments are intended only to illustrate the technical solutions of the present application and are not intended to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they may still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents; and such modifications or replacements do not deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A glass fiber sizing agent for colored SMC, characterized in that: The wetting agent comprises effective components and water; the solid content of the wetting agent is 3.8-13.8%; the effective components comprise a coupling agent, a film-forming agent, an antistatic agent, a leveling agent and a feel agent; the percentage of the solid mass of each effective component of the wetting agent to the total solid mass of the wetting agent is expressed as follows: The hand feeling agent is a high molecular polymer formed by polymerization of silicone oil containing long-chain alkyl groups and end-capping modification; 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 silicone-modified epoxy emulsion, and the second film-forming agent is a fast-penetrating unsaturated polyester emulsion; the mass ratio of the first film-forming agent to the second film-forming agent is 1:1 to 1:

5.

2. The glass fiber sizing for colored SMC according to claim 1, characterized in that: The percentage of the solid mass of each effective component of the infiltrant to the total solid mass of the infiltrant is expressed as follows: Wherein, the coupling agent is a silane coupling agent containing an unsaturated bond.

3. The glass fiber sizing agent for colored SMC according to claim 1 or 2, characterized in that: The leveling agent is a polyether-modified organic silicon compound.

4. The glass fiber sizing agent for colored SMC according to claim 1 or 2, characterized in that: The antistatic agent is at least one of sodium dodecyl sulfonate, lithium dodecyl sulfonate and potassium dodecyl sulfonate.

5. The glass fiber sizing for colored SMC according to claim 1 or 2, characterized in that: The organosilicon-modified epoxy emulsion is obtained by mixing epoxy-terminated polyether organosilicon as an emulsifier with epoxy resin and then uniformly dispersing the mixture in water.

6. The glass fiber sizing for colored SMC according to claim 5, characterized in that: The epoxy resin is at least one of bisphenol A epoxy resin, bisphenol S epoxy resin and bisphenol F epoxy resin; the epoxy equivalent of the epoxy resin is 600 to 3300 g / eq.

7. The glass fiber sizing for colored SMC according to claim 1 or 2, characterized in that: The fast-penetrating unsaturated polyester emulsion is obtained by polycondensing maleic anhydride doped with phthalic anhydride and propylene glycol, and the product is uniformly dispersed in water; the molecular weight of the fast-penetrating unsaturated polyester is 4000-15000 Da.

8. A method for preparing a glass fiber sizing for colored SMC according to any one of claims 1 to 7, characterized in that: The steps include: S1: Add the coupling agent and the feeling agent into water for pre-dispersion to prepare a coupling agent solution and a feeling agent solution respectively, and then mix the two solutions evenly; S2: pre-dissolving the antistatic agent and adding it to the solution obtained in step S1; S3: diluting the first film-forming agent with 6 to 12 times its volume of water; diluting the second film-forming agent with 3 to 9 times its volume of water, and adding the two to the solution obtained in step S2, mixing and stirring uniformly; S4: pre-dissolve the leveling agent and add it to the solution obtained in step S3, mix and stir until evenly mixed.

9. A glass fiber product produced by coating the glass fiber sizing for colored SMC according to any one of claims 1 to 8.

10. Use of the glass fiber product according to claim 9 in the field of construction.

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