Glass fiber impregnating compound as well as preparation method, product and application thereof

Abstract

The invention discloses a glass fiber impregnating compound. The solid mass of each component accounts for the total mass of the impregnating compound, and the impregnating compound comprises the following components in percentage by mass: 0.10-1.00% of a coupling agent; 0.20%-5.00% of an antistatic agent; 5.00% to 15.00% of a polyester emulsion; 0.20%-5.00% of a belt forming agent; 0.01% to 0.20% of a pH value regulator; 73.80 to 94.49 percent of water; the belt forming agent is at least one of polyurethane, epoxy resin or an aqueous solution of the polyurethane and the epoxy resin. The impregnating compound not only ensures the performances of jet chopping, infiltration, uniform dispersion and the like, but also keeps good banding performance, omits the heating and shaping treatment of the products, improves the internal production efficiency, shortens the internal production process and improves the product quality.

Description

Technical Field

[0001] This application belongs to the field of glass fiber surface treatment technology, specifically relating to a glass fiber wetting agent for spraying, its preparation method, product and application. Background Technology

[0002] The plied yarn used in glass fiber spraying must possess excellent ribbon-forming properties. The core reason for this is to ensure a smooth and efficient spraying process, reducing production problems and costs. During spray forming, if the yarn structure is loose and the fiber arrangement is disordered, it will rub and entangle with equipment components such as yarn guides and nozzles, causing spraying interruptions and resulting in poor ribbon-forming properties of the plied yarn. This makes it prone to snagging, and frequent shutdowns for adjustments not only reduce production efficiency but may also damage the equipment. Simultaneously, poor ribbon-forming properties generate a large amount of fuzz. These loose fibers fly around in the spraying area, polluting the working environment and affecting the health of operators. Furthermore, fuzz adhering to the surface of the formed product reduces its appearance quality, causing unevenness, defects, and other problems. It may also affect the product's mechanical properties, causing uneven strength and structural defects. Therefore, the sprayed yarn needs to have excellent ribbon-forming properties, with fibers tightly and orderly arranged into a ribbon, allowing for smooth transport within the spraying equipment, reducing friction with the equipment, avoiding snagging and jamming, and ensuring continuous and stable spraying. Furthermore, the regular strip structure can effectively suppress fuzz formation, ensure a clean working environment, improve product quality, and meet customers' needs for efficient and high-quality production.

[0003] The poor ribbon-forming properties of fiberglass sprayed yarn are mainly due to the following reasons: 97%-100% of the fiberglass yarn is inorganic glass, and 0%-3% is coated with an organic sizing agent. This sizing agent must reduce friction on the fiber surface, minimizing friction between the fiber and equipment during drawing and winding processes to prevent fiber breakage. It must also form a uniform, continuous protective film on the fiber surface to protect the fiber from environmental damage, such as preventing moisture erosion, maintaining fiber bundles, ensuring neat fiber arrangement, and enhancing the bonding strength between the matrix materials. Even after ensuring lubrication, bundle formation, bonding strength, and dispersion, it is difficult to guarantee the ribbon-forming performance of the fiberglass sprayed yarn in winter. When the ribbon-forming properties of the fiberglass sprayed yarn are poor, the strands cannot bond well together, leading to scattering and even tube collapse during use, significantly impacting customer experience.

[0004] Currently, fiberglass manufacturers mainly reheat the plied yarn at high temperatures to make the sizing agent adhere to each other, thereby improving the performance of the sprayed yarn into tape and ultimately achieving smooth performance for customers. However, reheating brings a lot of waste in energy, manpower, space, and time. At the same time, the plied yarn will also affect various properties of the sizing agent due to reheating.

[0005] If a jet yarn product has good impregnation properties and can guarantee dispersion performance under high summer temperatures, it is difficult to guarantee its tape-forming performance in winter. When the tape-forming property of glass fiber plied yarn is poor, downstream customers will experience scattering or even collapse of the yarn during use, which will greatly affect their use. Summary of the Invention

[0006] This application aims to provide a glass fiber sizing agent. Glass fibers coated with this sizing agent can change the physical and chemical properties of the glass fiber surface, effectively improve the bonding between the glass fiber and the matrix resin, and the product has high dispersibility, low hairiness, fast impregnation speed, excellent antistatic properties, and good tape-forming properties.

[0007] This application describes a glass fiber sizing agent composition developed to achieve high performance in jet-blown products while eliminating the need for reheating and setting. By adding a tape-forming agent to the jet-blown yarn sizing agent, the composition ensures good jetting, sizing, and dispersion properties, while maintaining good tape-forming performance. This reduces the need for heat setting, improves internal production efficiency, shortens the internal production process, and enhances product quality.

[0008] To achieve the above objectives, this application adopts the following technical solution: According to one aspect of this application, a glass fiber impregnating agent is provided, wherein the percentage of the solid mass of each component to the total mass of the impregnating agent is expressed as follows: Coupling agent 0.10%-1.00%; Antistatic agent 0.20%-5.00%; Polyester emulsion 5.00%-15.00%; Stripping agent: 0.20%-5.00%; pH adjuster 0.01%-0.20%; Water content: 73.80-94.49%; The tape-forming agent is at least one of polyurethane, epoxy resin, or an aqueous solution thereof.

[0009] Preferably, the percentage of the solid mass of each component to the total mass of the treatment agent is expressed as follows: Coupling agent 0.15%-0.80% Antistatic agent 0.20%-4.00%; Polyester emulsion 8.00%-15.0%; Stripping agent: 0.30%-4.00%; Glacial acetic acid 0.01%-0.15% Water content: 76.05% - 91.34%.

[0010] Preferably, the coupling agent is a composition of methacryloxypropyltrimethoxysilane and styrylaminotrimethoxysilane; wherein the mass ratio of methacryloxypropyltrimethoxysilane to styrylaminotrimethoxysilane is 10:1-5:1.

[0011] Preferably, the antistatic agent is at least one of inorganic antistatic agents, cationic antistatic agents, and nonionic antistatic agents; more preferably, it is one or a mixture of two of lithium nitrate and sodium sulfate in any proportion. Preferably, the polyester emulsion is a composition of saturated polyester emulsion and unsaturated polyester emulsion; wherein the mass ratio of the saturated polyester emulsion to the unsaturated polyester emulsion is 6:1.

[0012] Preferably, the tape-forming agent is at least one of polyurethane, epoxy resin, or an aqueous solution thereof.

[0013] Preferably, the polyurethane is a low molecular weight polyurethane-type polyurethane.

[0014] Preferably, the epoxy resin is a glycerol ether epoxy resin with an epoxy equivalent of 160-260.

[0015] In this application, water serves as the dispersed phase of each component in the wetting agent, and deionized water is preferred.

[0016] The coupling agent used in this application is a combination of methacryloxypropyltrimethoxysilane and styreneaminotrimethoxysilane. Methacryloxy (-OCOC(CH3)=CH2) is reactive and can participate in subsequent polymerization reactions, such as copolymerizing with double bonds in unsaturated polyester resins, thus enhancing the bonding force between the glass fiber and the resin matrix. Introducing styreneaminotrimethoxysilane improves the product's cutability, facilitating jet shaving and reducing blade wear. Furthermore, the amino group of styreneaminotrimethoxysilane has strong polarity and reactivity, forming hydrogen bonds with hydroxyl groups on the glass fiber surface and reacting with certain components in the tape-forming agent (such as epoxy groups in epoxy resin), enhancing the bond between the fiber and the tape-forming agent. Further, the mass ratio of methacryloxypropyltrimethoxysilane to styreneaminotrimethoxysilane is 10:1-5:1. Styrene-aminotrimethoxysilane can improve the cutting properties of the product, which is beneficial for jet shaving and reducing blade wear. However, excessive content leads to high cost and makes the yarn too stiff; too little or no addition makes cutting difficult. In some embodiments, the mass ratio of methacryloxypropyltrimethoxysilane to styrene-aminotrimethoxysilane can be 5:1, 5.09:1, 5.33:1, 5.45:1, 5.83:1, 7.5:1, or 8.57:1.

[0017] The core of glass fiber tape formation lies in "the formation of moderate adhesion between fibers," and this adhesion depends on the continuity of the tape-forming agent molecules on the fiber surface and the intermolecular forces. The tape-forming agent in this application is at least one of polyurethane, epoxy resin, or an aqueous solution thereof, possessing low viscosity and high chemical stability, providing good weather resistance, abrasion resistance, and impact resistance. Specifically, at least one of a low molecular weight polyurethane-type polyurethane and a glycerol ether epoxy resin emulsion or aqueous solution with an epoxy equivalent of 160-260 can be selected. Low molecular weight (molecular weight 4000-9000) polyurethane-type polyurethane and glycerol ether epoxy resin emulsions or aqueous solutions with an epoxy equivalent of 160-260 can be stably dissolved in pure water, avoiding pipe and equipment blockage, etc., while possessing moderate adhesion. In winter use, it can effectively bind the yarns together, thereby improving the tape-forming performance of the jet yarn and enhancing the smoothness of customer use; simultaneously, the product will not cause excessive adhesion or other adverse phenomena such as fraying when used at high temperatures in summer. In low-temperature environments (winter), if the molecular weight of polyurethane is too large, the chain segments will become stiff and "cured and brittle," making it impossible to form a continuous and flexible film on the fiber surface, resulting in insufficient adhesion and yarn breakage. Polyurethane with a smaller molecular weight has shorter molecular chains and less chain segment rotation resistance (lower glass transition temperature Tg, usually <0℃), and can maintain good flexibility even at low temperatures. It can closely adhere to the fiber surface to form a uniform film and generate stable adhesion through the polarity of the urethane bond (forming hydrogen bonds with hydroxyl groups / coupling agent amino groups on the fiber surface), thus preventing the yarn from becoming tangled in winter.

[0018] The core design of this tape-forming agent lies in creating a "moderate, reversible adhesive force" between multiple fibers, ensuring the yarn forms a tape (without scattering or collapsing) while not affecting subsequent spraying and dispersion. Unlike film-forming agents that act on the surface of a single glass fiber to form a "coating layer," this agent does not involve the bonding and aggregation between multiple components (e.g., it does not bond multiple fibers into a tape). Instead, it forms a "continuous, dense protective film" on the surface of a single fiber / matrix. Its core function is to isolate external environmental moisture, improve product hardness and weather resistance, and does not directly regulate the adhesion between fibers.

[0019] The polyester emulsion is a composition of saturated and unsaturated polyester emulsions. The saturated polyester emulsion primarily provides rapid resin penetration and good resin binding, improves mechanical properties, and reduces the likelihood of glass fiber rebound. A small amount of unsaturated polyester emulsion in the composition can improve the bundled properties of the glass fiber and the stiffness of the product, as well as enhance the dispersion performance during spraying. Maintaining a mass ratio of 6:1 between the two emulsions effectively balances these various properties.

[0020] According to a second aspect of this application, a method for preparing the aforementioned glass fiber impregnating agent is provided, specifically comprising the following steps: Add 20-30 times the mass of the coupling agent to water in the first container, then add the predetermined mass of pH adjuster, and add the predetermined mass of coupling agent while stirring, stirring until the mixture is evenly dispersed and clear. Add 1-2 times the amount of room temperature water to the second container, then add more polyester emulsion and stir until evenly dispersed; preferably, add 2 times the amount of room temperature water. Add 1-2 times the amount of room temperature water to the third container to form the sizing agent, then add the sizing agent again and stir until evenly dispersed; preferably, add 2 times the amount of room temperature water. Add 8-10 times the amount of antistatic agent to water at 80-100℃ in the fourth container, then add the antistatic agent, stir until evenly dispersed, and then let it cool to room temperature; preferably, add 10 times the amount of water at 80-100℃. The raw materials from the first to the fourth containers are added to the fifth container, and then the remaining room temperature water is added. After stirring and dispersing evenly, the glass fiber impregnating agent is obtained.

[0021] Normal temperature generally refers to 20-30℃.

[0022] According to a third aspect of this application, a glass fiber yarn product produced by coating with the aforementioned glass fiber sizing agent is provided.

[0023] According to a fourth aspect of this application, the glass fiber sizing agent is provided for use in the production of glass fiber electronic yarn.

[0024] Compared with the prior art, the beneficial effects of this application are reflected in: First, the glass fiber impregnating agent of this application introduces a ribbon-forming agent, which can improve the ribbon-forming performance of glass fiber and avoid the waste of a lot of energy, manpower, space and time caused by the heating and setting of glass fiber ply yarn. At the same time, the various properties of the impregnating agent will be affected by reheating. It can solve the ribbon-forming problem of glass fiber ply yarn in one go and shorten the production process of glass fiber sprayed yarn to a certain extent.

[0025] Second: The introduction of the ribboning agent increases the wrapping of the glass fiber yarn, reduces friction, and reduces the generation of fuzz, etc. At the same time, the low molecular weight ribboning agent also effectively improves the compatibility between the glass fiber ply yarn and the resin, without affecting the various properties of the glass fiber ply yarn and the composite material.

[0026] Third: Through the synergistic effect of the tape-forming agent, coupling agent, polyester emulsion, etc., the product has good bundle properties, and the product is more evenly dispersed during spraying; the resin penetrates quickly and has good bonding properties, and the product is less prone to springback at corners, resulting in high production efficiency for customers and high mechanical properties of the product; the product has good tape-forming properties, avoiding energy waste and increased costs caused by secondary shaping, shortening the internal production process, and improving internal production efficiency. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0028] In some alternative embodiments, a glass fiber impregnating agent is provided, wherein the percentage of the solid mass of each component relative to the total mass of the impregnating agent is expressed as follows: Coupling agent 0.10%-1.00%; Antistatic agent 0.20%-5.00%; Polyester emulsion 5.00%-15.00%; Stripping agent: 0.20%-5.00%; pH adjuster 0.01%-0.20%; Water content: 73.80-94.49%; The tape-forming agent is at least one of polyurethane, epoxy resin, or an aqueous solution thereof.

[0029] In some alternative implementations, the percentage of the solid mass of each component relative to the total mass of the treatment agent is expressed as follows: Coupling agent 0.15%-0.80% Antistatic agent 0.20%-4.00%; Polyester emulsion 8.00%-15.0%; Stripping agent: 0.30%-4.00%; Glacial acetic acid 0.01%-0.15% Water content: 76.05% - 91.34%.

[0030] Preferably, the coupling agent is a composition of methacryloxypropyltrimethoxysilane and styrylaminotrimethoxysilane; wherein the mass ratio of methacryloxypropyltrimethoxysilane to styrylaminotrimethoxysilane is 10:1-5:1.

[0031] In some optional embodiments, the polyurethane is a low molecular weight polyurethane-based polyurethane, and the epoxy resin is at least one of a glycerol ether epoxy resin or an aqueous solution thereof with an epoxy equivalent of 160-260. The antistatic agent is at least one of an inorganic antistatic agent, a cationic antistatic agent, or a nonionic antistatic agent; more preferably, it is one or a mixture of two of lithium nitrate and sodium sulfate in any proportion. In some optional embodiments, the polyester emulsion is a composition of a saturated polyester emulsion and an unsaturated polyester emulsion; wherein the mass ratio of the saturated polyester emulsion to the unsaturated polyester emulsion is 6:1.

[0032] The following are specific examples of glass fiber impregnating agents: Table 1 shows the percentage of solid mass of each component in the composition of the specific embodiments relative to the total mass of the wetting agent. The corresponding values ​​are mass percentages.

[0033] It should be noted that the specific types, contents, and combinations of the components selected in Table 1 do not limit the scope of protection of this application.

[0034] Table 1 List of specific examples of wetting agents

[0035] In each embodiment, the coupling agents are: methacryloyloxypropyltrimethoxysilane, which is Jiangsu Chenguang Coupling Agent Co., Ltd.; and styrylaminotrimethoxysilane, which is Dow Chemical Company. The polyester emulsion grade is TX111H, produced by Jushi Branch Plant; among which, TX111H is a mixed liquid, containing saturated polyester emulsion and unsaturated polyester emulsion, with a mass ratio of 6:1.

[0036] Ribboning agent 1: The small molecule polyurethane is TX811, which is a polyurethane-type polyurethane with a molecular weight of 4000-9000. Banding agent 2: TX-A is a glycerol ether epoxy resin emulsion or its aqueous solution with an epoxy equivalent of 160-260; The antistatic agent is lithium nitrate, manufactured by Guangzhou Guanghua. The pH adjuster is glacial acetic acid. The preparation method steps are as follows: 1S: Add 20-30 times the mass of the coupling agent to water in the first container, then add the predetermined mass of glacial acetic acid, and add the predetermined mass of coupling agent while stirring. Stir until the mixture is evenly dispersed and clear. 2S: Add room temperature water twice the volume of polyester emulsion to the second container, then add more polyester emulsion and stir until evenly dispersed; 3S: Add room temperature water twice the amount of the binding agent to the third container, then add the binding agent and stir until evenly dispersed; 4S: Add 10 times the amount of antistatic agent to 80-100℃ water in the fourth container, then add the antistatic agent, stir until evenly dispersed, and then let it cool to room temperature; 5S: Add the raw materials from the first to the fourth containers to the fifth container, then add the remaining room temperature water, stir evenly and disperse to obtain the glass fiber impregnating agent.

[0037] Comparative test cases To further demonstrate the beneficial effects of this application, we selected sizing agents with different formulations and commonly used sizing agents for jet yarn as comparative examples (Comparative Examples 1 to 4) for comparative testing.

[0038] The formulation contents of Comparative Examples 1-3 are shown in Table 2.

[0039] Table 2

[0040] Among them, the coupling agents are: methacryloyloxypropyltrimethoxysilane, which is from Jiangsu Chenguang Coupling Agent Co., Ltd.; and styrylaminotrimethoxysilane, which is from Dow Chemical Company. Polyester emulsion: Comparative Examples 1 and 2 are of grade TX111H, produced by Jushi Branch Plant; the mass ratio of saturated polyester emulsion to unsaturated polyester emulsion in the polyester emulsion of Comparative Example 3 is 5:1.

[0041] Ribbon forming agent 1: The small molecule polyurethane is TX811, which is a polyurethane-type polyurethane. The molecular weight of ribbon forming agent 1 used in Comparative Examples 1 and 3 is 10,000-15,000, and it is produced by Jushi Branch Plant. The molecular weight of Comparative Example 2 is 4,000-9,000. Ribboning agent 2: TX-A is a glycerol ether epoxy resin emulsion or its aqueous solution with an epoxy equivalent of 160-260. The epoxy equivalent of Comparative Examples 1 and 3 is 160-260. The ribboning agent 2 used in Comparative Example 2 has an epoxy equivalent of 100-150 and is also produced by Jushi Branch Plant. Comparative Example 4 The content of each component in the wetting agent is expressed as a percentage by mass as follows: Methacryloxypropyltrimethoxysilane 0.55%; Polyvinyl acetate emulsion 11.40%; Nonionic polyurethane emulsion 2.00%; Antistatic agent 0.28% Acetic acid 0.16%; Water balance.

[0042] The above-described embodiments and comparative examples were applied to the production of glass fiber, and their spraying and other properties were tested and compared.

[0043] Table 3 Performance test results of the examples and comparative examples

[0044] Table 2 (continued) Performance test results of the examples and comparative examples

[0045] Through the above product performance tests and comparisons, especially regarding the tape-forming performance, the tape-forming performance of Comparative Examples 1-4 is relatively poor, and requires secondary hot air setting to improve the tape-forming performance. In particular, the tape-forming performance of Examples 4-6 is excellent, meeting the requirement of not needing setting, and the product performance meets the design requirements. Furthermore, the addition of styrene-aminotrimethoxysilane also improves the cutting performance, and the overall product performance fully meets customer needs.

[0046] As can be seen from the above test examples, the glass fibers made using the impregnating agent provided in this application have better overall performance. Specifically, the glass fibers have better cutting and tape-forming performance, faster impregnation and better molding performance, less yarn shedding during use, and are more environmentally friendly. They do not require secondary shaping, which reduces energy waste and performance damage.

[0047] In summary, the use of the sizing agent of this application to coat glass fibers can change the physical and chemical properties of the glass fiber surface, improve the bundle and cutting performance of the glass fibers, increase the tape forming performance of the product, improve the smoothness of glass fiber use, and reduce the accumulation of fuzz, etc. The resulting glass fibers have moderate stiffness, fast impregnation speed and good mold-forming performance, and are easier to cut with less yarn waste.

[0048] Finally, it should be noted that in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0049] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A glass fiber impregnating agent, characterized in that, The percentage of the solid mass of each component relative to the total mass of the wetting agent is expressed as follows: Coupling agent 0.10%-1.00%; Antistatic agent 0.20%-5.00%; Polyester emulsion 5.00%-15.00%; Stripping agent: 0.20%-5.00%; pH adjuster 0.01%-0.20%; Water content: 73.80-94.49%; The tape-forming agent is at least one of polyurethane, epoxy resin, or an aqueous solution thereof.

2. The glass fiber impregnating agent according to claim 1, characterized in that, The percentage of the solid mass of each component relative to the total mass of the wetting agent is expressed as follows: Coupling agent 0.15%-0.80% Antistatic agent 0.20%-4.00%; Polyester emulsion 8.00%-15.0%; Stripping agent: 0.30%-4.00%; pH adjuster 0.01%-0.15%; Water content: 76.05% - 91.34%.

3. The glass fiber impregnating agent as described in claim 1 or 2, characterized in that, The coupling agent is a composition of methacryloyloxypropyltrimethoxysilane and styrylaminotrimethoxysilane; wherein the mass ratio of methacryloyloxypropyltrimethoxysilane to styrylaminotrimethoxysilane is 10:1-5:

1.

4. The glass fiber impregnating agent according to claim 1 or 2, characterized in that, The antistatic agent is one of lithium nitrate and sodium sulfate, or a mixture of two in any proportion.

5. The glass fiber impregnating agent according to claim 1 or 2, characterized in that, The polyester emulsion is a composition of saturated polyester emulsion and unsaturated polyester emulsion; wherein the mass ratio of the saturated polyester emulsion to the unsaturated polyester emulsion is 6:

1.

6. The glass fiber impregnating agent according to claim 1 or 2, characterized in that, The antistatic agent is at least one of inorganic antistatic agents, cationic antistatic agents, and nonionic antistatic agents; The pH adjuster is glacial acetic acid.

7. The glass fiber impregnating agent according to claim 1 or 2, characterized in that, The polyurethane is a low molecular weight polyurethane of the polyurethane type.

8. The glass fiber impregnating agent according to claim 1 or 2, characterized in that, The epoxy resin is a glycerol ether epoxy resin with an epoxy equivalent of 160-260.

9. A method for preparing a glass fiber impregnating agent as described in any one of claims 1-8, characterized in that, Includes the following steps: Add 20-30 times the mass of the coupling agent to water in the first container, then add the predetermined mass of pH adjuster, and add the predetermined mass of coupling agent while stirring, stirring until the mixture is evenly dispersed and clear. Add 1-2 times the amount of room temperature water to the second container, then add more polyester emulsion and stir until evenly dispersed. Add 1-2 times the amount of room temperature water to the third container to form the sizing agent, then add the sizing agent and stir until evenly dispersed. Add 8-10 times the amount of antistatic agent to water at 80-100℃ in the fourth container, then add the antistatic agent, stir until evenly dispersed, and then let it cool to room temperature. The raw materials from the first to the fourth containers are added to the fifth container, and then the remaining room temperature water is added. After stirring and dispersing evenly, the glass fiber impregnating agent is obtained.

10. A glass fiber yarn product produced by coating with the glass fiber sizing agent according to any one of claims 1-8.

11. The application of the glass fiber sizing agent as described in any one of claims 1-8 in the field of glass fiber yarn production.

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