An electronic grade industrial glass fiber yarn impregnant and a method for preparing the same

Abstract

This invention belongs to the technical field of glass fiber production auxiliaries, and discloses an electronic-grade industrial glass fiber yarn sizing agent and its preparation method. The method includes the following steps: reacting HTPB and a hydrogen-containing silane coupling agent under solvent and platinum acid catalyst conditions, followed by the addition of diisocyanate to obtain a polyurethane-structured macromolecular coupling agent; preparing an acetic acid aqueous solution with a pH of 4-5, and sequentially adding an emulsifier, softener, and macromolecular coupling agent to carry out a hydrolysis reaction under heating and stirring to obtain a macromolecular coupling agent hydrolysate; diluting the aqueous polyurethane emulsion, then adding a lubricant and the macromolecular coupling agent hydrolysate, mixing, and homogenizing to obtain the electronic-grade industrial glass fiber yarn sizing agent. The sizing agent of this invention can significantly improve the problems of viscosity increase and uneven coating during use, and increase the yield of glass fiber impregnation treatment.

Description

Technical Field

[0001] This invention belongs to the field of glass fiber production auxiliary technology, specifically relating to an electronic-grade industrial glass fiber yarn impregnating agent and its preparation method. Background Technology

[0002] Currently, starch-based sizing agents are mainly used in conventional industrial glass fiber yarns. They offer the advantage of low cost and can be modified through compounding to improve lubrication and dispersibility on glass fibers. However, their bonding strength to glass fibers still needs improvement, making them unsuitable for the requirements of high-strength, high-cohesion electronic-grade industrial glass fiber yarns. Polyurethane sizing agents, with their polar urethane bonds, exhibit superior bonding and cohesion to glass fibers compared to starch-based film-forming agents, and are gradually gaining dominance in high-end glass fiber products.

[0003] Existing polyurethane sizing agent formulations typically incorporate small-molecule silane coupling agents to further enhance their bonding with glass fiber. However, these small-molecule silane coupling agents exhibit high self-crosslinking activity after alcohol condensation in aqueous solutions or upon exposure to air. This self-crosslinking reduces the compatibility between the coupling agent and the polyurethane film-forming agent. In practical applications, during the winding process, the sizing agent is coated onto the glass fiber. Due to the reduced compatibility of the coupling agent, the film-forming agent adheres unevenly, resulting in unsatisfactory film formation. Furthermore, with prolonged use, the viscosity of the sizing agent exposed to air gradually increases, further exacerbating uneven coating and affecting subsequent product use. This negatively impacts the final glass fiber product quality, leading to numerous defects such as: 1. Severe increase in sizing agent viscosity over time, resulting in uneven sizing agent coating on the glass fiber surface; 2. Poor film formation when the sizing agent is applied to the glass fiber surface, easily causing monofilament breakage; 3. Reduced processing efficiency due to uneven sizing agent coating on the glass fiber surface; 4. Significantly increased sizing agent consumption. Summary of the Invention

[0004] To address the issues of viscosity increase and uneven coating in existing polyurethane emulsion sizing agents, this invention proposes an electronic-grade industrial glass fiber sizing agent and its preparation method. By developing a macromolecular coupling agent suitable for polyurethane emulsion systems, its stability is improved, and its compatibility and bonding force with polyurethane film-forming agents are enhanced. The resulting sizing agent exhibits stable viscosity during use and can uniformly adhere to the surface of glass fibers, forming a high-strength protective film that can bundle and protect the glass fibers. This allows the glass fibers to bundle a fixed number of monofilaments together, making them softer and less prone to breakage, thereby achieving the spinnability of the glass fibers.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A method for preparing an electronic-grade industrial glass fiber yarn impregnating agent includes the following steps:

[0007] (1) Preparation of macromolecular coupling agent: Hydroxyl-terminated polybutadiene (HTPB) and hydrogen-containing silane coupling agent are dissolved in toluene, and chloroplatinic acid catalyst is added and heated to catalyze the reaction to obtain hydroxyl-terminated polybutadiene containing coupling groups; then diisocyanate is added and the reaction is continued at a constant temperature. After the reaction is completed, the solvent is removed by drying to obtain a polyurethane-structured macromolecular coupling agent.

[0008] (2) Preparation of macromolecular coupling agent hydrolyzed emulsion: Prepare an acetic acid aqueous solution with a pH of 4-5, then add emulsifier and softener and stir to dissolve, then add the polyurethane structure macromolecular coupling agent obtained in step (1) and heat and stir to carry out hydrolysis reaction to obtain macromolecular coupling agent hydrolyzed emulsion.

[0009] (3) Preparation of sizing agent: dilute water-based polyurethane emulsion, then add lubricant and hydrolyzed emulsion of macromolecular coupling agent obtained in step (2), mix and homogenize to obtain the electronic grade industrial glass fiber yarn sizing agent.

[0010] Preferably, the HTPB has a hydroxyl value of 0.6 to 2.0 mmol / g (corresponding to a theoretical number-average molecular weight of 1000 to 3300) and a 1,2-vinyl structure content of >20% (such as NISSO-PB G series hydroxyl polybutadiene (G-1000 / G-2000 / G-3000)).

[0011] Preferably, the hydrogen-containing silane coupling agent is trimethoxysilane or triethoxysilane, and the amount of hydrogen-containing silane coupling agent added is 5% to 40% of the mass of HTPB.

[0012] Preferably, the temperature of the heating catalytic reaction is 70–90°C, and the time is 3–6 hours.

[0013] Preferably, the diisocyanate is any one of isophorone diisocyanate, diphenylmethane diisocyanate, and toluene diisocyanate, and the molar ratio of diisocyanate to HTPB is 0.5–0.7:1. By using an excess of HTPB, the main chain end groups of the macromolecular coupling agent are composed of hydroxyl groups with lower activity, ensuring its subsequent emulsification stability.

[0014] Preferably, the emulsifier is any one of fatty alcohol polyoxyethylene ether and alkylphenol polyoxyethylene ether.

[0015] Preferably, the fabric softener is polyethylene glycol or polyether-modified cyclosiloxane, more preferably a polyether-modified cyclosiloxane fabric softener, and the preparation method of the polyether-modified cyclosiloxane fabric softener is as follows:

[0016] Tetramethylcyclotetrasiloxane (D4H) and allyl polyethylene glycol were dissolved in toluene at a molar ratio of 1:2 to 4. Chloroplatinic acid catalyst was added and heated to catalyze the reaction, resulting in a polyether-modified cyclosiloxane softener.

[0017] The present invention utilizes a polyether-modified cyclosiloxane softener with a polyether branched structure and a central cyclosiloxane structure, which has lower surface tension and better softening effect, and can better promote the mixing compatibility of macromolecular coupling agents and polyurethane film-forming agents and improve film-forming effect.

[0018] Preferably, in the preparation step of the macromolecular coupling agent hydrolyzed emulsion, the mass ratio of emulsifier, softener and polyurethane-structured macromolecular coupling agent added is 0.3-0.6:0.2-0.4:1; and the solid content of the macromolecular coupling agent hydrolyzed emulsion is 20%-40%.

[0019] Preferably, in the preparation step of the wetting agent, the aqueous polyurethane emulsion is diluted to a solid content of 6% to 15%; the lubricant is a fatty acid ester lubricant, and the amount of lubricant added is 2% to 6% of the solid content of the aqueous polyurethane emulsion; the amount of the hydrolyzed emulsion of the macromolecular coupling agent added is 5% to 20% of the solid content of the aqueous polyurethane emulsion.

[0020] An electronic-grade industrial glass fiber yarn impregnating agent is prepared by the above method.

[0021] The principle of this invention is as follows: Hydroxyl-terminated polybutadiene (HTPB) side-chain vinyl groups are grafted onto a hydrogen-containing silane coupling agent via a hydrosilylation reaction. This is followed by a prepolymerization reaction with diisocyanate to obtain a macromolecular coupling agent with a polyurethane main chain and silane coupling groups on the side chains. This macromolecular coupling agent exhibits good compatibility and bonding strength with the polyurethane film-forming agent. Simultaneously, the coupling groups it contains enhance the bonding strength with glass fibers, thereby improving film formation and glass fiber wetting. Furthermore, by grafting silane coupling groups onto the polyurethane main chain, the self-condensation and crosslinking activity of small-molecule silane coupling groups is significantly reduced. Moreover, by pre-hydrolyzing the silane coupling groups in an acidic solution, the unstable alkoxy groups are hydrolyzed into relatively stable silanol groups with strong bonding strength to glass fibers, preventing slow hydrolysis and crosslinking reactions during application and improving the stability of the bond with glass fibers. These combined effects improve the viscosity stability of the wetting agent and the stability of the coating effect.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] (1) The sizing agent of the present invention is a polyurethane film-forming agent with higher film-forming strength, which can meet the requirements of high-strength, high-cohesion electronic-grade industrial glass fiber yarn.

[0024] (2) The wetting agent of the present invention adopts a macromolecular coupling agent with a polyurethane structure, and through a pre-hydrolysis reaction, it can improve the problem of viscosity increase and uneven coating during the use of the wetting agent. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0026] Example 1

[0027] A method for preparing an electronic-grade industrial glass fiber yarn impregnating agent includes the following steps:

[0028] (1) Preparation of macromolecular coupling agent: 100 parts by mass of hydroxyl-terminated polybutadiene (NISSO-PB G-1000) and 20 parts by mass of trimethoxysilane were added to toluene for dissolution. Chloroplatinic acid catalyst was added and heated to 75°C for 5 h for catalytic reaction. The active hydrogen (Si-H) content in the product was determined by bromination titration to determine the reaction endpoint and obtain hydroxyl-terminated polybutadiene containing coupling groups. Then, 13 parts by mass of isophorone diisocyanate were added and the reaction was continued at the temperature for 1 h. The isocyanate group content in the product was determined to determine the reaction endpoint. After the reaction was completed, the solvent was removed by drying to obtain a macromolecular coupling agent with a polyurethane structure.

[0029] (2) Preparation of hydrolyzed emulsion of macromolecular coupling agent: Add pure water at 60°C to the preparation tank, add acetic acid and stir until the pH value is about 4.5, then add AEO-7 emulsifier and PEG-400 softener and stir to dissolve, then add the polyurethane structure macromolecular coupling agent obtained in step (1) and keep warm and stir for hydrolysis reaction for 2 hours. The mass ratio of AEO-7 emulsifier, PEG-400 softener and macromolecular coupling agent is 0.4:0.3:1, and a hydrolyzed emulsion of macromolecular coupling agent with a solid content of 30% is obtained.

[0030] (3) Preparation of sizing agent: Take 100 parts by weight of waterborne polyurethane emulsion (Anda Huatai AH-1704-1 nonionic waterborne polyurethane, solid content 30%) and dilute with 1.5 times deionized water. Then add 1.5 parts by weight of ethyl oleate lubricant and 15 parts by weight of macromolecular coupling agent hydrolysate obtained in step (2), mix and homogenize to obtain the electronic grade industrial glass fiber yarn sizing agent.

[0031] The initial viscosity of the sizing agent obtained in this embodiment was 4.1 cps, and the viscosity was 4.6 cps after 48 hours of continuous operation, showing no significant change from the start to the end of use. The film strength of the sizing agent, measured using a burst strength tester, was 530 kPa. The glass fiber breakage rate during fiber drawing was 1.15%, and the finished product hairiness rate was 2.20%. The uneven coating phenomenon disappeared, and the yield increased to 96%.

[0032] Example 2

[0033] A method for preparing an electronic-grade industrial glass fiber yarn impregnating agent includes the following steps:

[0034] (1) Preparation of macromolecular coupling agent: 100 parts by mass of hydroxyl-terminated polybutadiene (NISSO-PB G-2000) and 30 parts by mass of triethoxysilane were added to toluene for dissolution. Chloroplatinic acid catalyst was added and heated to 80°C for 5 h to catalyze the reaction. The active hydrogen (Si-H) content in the product was determined by bromination titration to determine the reaction endpoint, and hydroxyl-terminated polybutadiene containing coupling groups was obtained. Then, 8 parts by mass of diphenylmethane diisocyanate were added and the reaction was continued at the temperature for 1 h. The isocyanate group content in the product was determined to determine the reaction endpoint. After the reaction was completed, the solvent was removed by drying to obtain a macromolecular coupling agent with a polyurethane structure.

[0035] (2) Preparation of hydrolyzed emulsion of macromolecular coupling agent: Add pure water at 60°C to the preparation tank, add acetic acid and stir until the pH value is about 4.5, then add AEO-7 emulsifier and PEG-400 softener and stir to dissolve, then add the polyurethane structure macromolecular coupling agent obtained in step (1) and keep warm and stir for hydrolysis reaction for 2 hours. The mass ratio of AEO-7 emulsifier, PEG-400 softener and macromolecular coupling agent is 0.5:0.2:1, and a hydrolyzed emulsion of macromolecular coupling agent with a solid content of 40% is obtained.

[0036] (3) Preparation of sizing agent: Take 100 parts by weight of waterborne polyurethane emulsion (same as in Example 1) and dilute it with 1.5 times the amount of deionized water. Then add 1.5 parts by weight of ethyl oleate lubricant and 10 parts by weight of the hydrolyzed emulsion of macromolecular coupling agent obtained in step (2), mix and homogenize to obtain the electronic grade industrial glass fiber yarn sizing agent.

[0037] The initial viscosity of the sizing agent obtained in this embodiment was 4.3 cps, and the viscosity was 4.7 cps after 48 hours of continuous operation, showing no significant change from the start to the end of use. The film strength of the sizing agent was measured to be 550 kPa using a burst strength tester. The glass fiber breakage rate during fiber drawing was 1.06%, and the finished product hairiness rate was 1.45%. The uneven coating phenomenon disappeared, and the yield increased to 97%.

[0038] Example 3

[0039] A method for preparing an electronic-grade industrial glass fiber yarn impregnating agent includes the following steps:

[0040] (1) Preparation of macromolecular coupling agent: 100 parts by mass of hydroxyl-terminated polybutadiene (NISSO-PB G-3000) and 10 parts by mass of trimethoxysilane were added to toluene and dissolved. Chloroplatinic acid catalyst was added and heated to 80°C for 4 hours to catalyze the reaction. The active hydrogen (Si-H) content in the product was determined by bromination titration to determine the reaction endpoint and obtain hydroxyl-terminated polybutadiene containing coupling groups. Then, 3 parts by mass of toluene diisocyanate were added and the reaction was continued at the temperature for 1 hour. The isocyanate group content in the product was determined to determine the reaction endpoint. After the reaction was completed, the solvent was removed by drying to obtain a macromolecular coupling agent with a polyurethane structure.

[0041] (2) Preparation of hydrolyzed emulsion of macromolecular coupling agent: Add pure water at 60°C to the preparation tank, add acetic acid and stir until the pH value is about 4.5, then add AEO-7 emulsifier and PEG-400 softener and stir to dissolve, then add the polyurethane structure macromolecular coupling agent obtained in step (1) and keep warm and stir for hydrolysis reaction for 2 hours. The mass ratio of AEO-7 emulsifier, PEG-400 softener and macromolecular coupling agent is 0.3:0.3:1, and a hydrolyzed emulsion of macromolecular coupling agent with a solid content of 20% is obtained.

[0042] (3) Preparation of sizing agent: Take 100 parts by weight of waterborne polyurethane emulsion (same as in Example 1) and dilute it with 1.5 times the amount of deionized water. Then add 1.5 parts by weight of ethyl oleate lubricant and 20 parts by weight of the hydrolyzed emulsion of macromolecular coupling agent obtained in step (2), mix and homogenize to obtain the electronic grade industrial glass fiber yarn sizing agent.

[0043] The initial viscosity of the sizing agent obtained in this embodiment was 4.6 cps, and the viscosity was 5.0 cps after 48 hours of continuous operation, with no significant change in viscosity from the start to the end of use. The film strength of the sizing agent was measured to be 520 kPa using a burst strength tester. The glass fiber breakage rate during fiber drawing was 1.20%, and the finished product hairiness rate was 2.63%. The uneven coating phenomenon disappeared, and the yield increased to 96%.

[0044] Example 4

[0045] A method for preparing an electronic-grade industrial glass fiber yarn impregnating agent, wherein a polyether-modified cyclosiloxane softener is used to replace the PEG-400 softener in Example 3, and the rest is the same as in Example 3.

[0046] The preparation method of the polyether-modified cyclosiloxane softener is as follows:

[0047] Tetramethylcyclotetrasiloxane (D4H) and allyl polyethylene glycol (APEG-400) were dissolved in toluene at a molar ratio of 1:4. Chloroplatinic acid catalyst was added and the mixture was heated to 80°C for 4 hours to catalyze the reaction. The double bond content in the product was measured to determine the reaction endpoint, and polyether-modified cyclosiloxane softener was obtained.

[0048] The initial viscosity of the sizing agent obtained in this embodiment was 3.6 cps, and the viscosity was 4.0 cps after 48 hours of continuous operation, with no significant change in viscosity from the start to the end of use. The film strength of the sizing agent was measured to be 540 kPa using a burst strength tester. The glass fiber breakage rate during fiber drawing was 0.67%, and the finished product hairiness rate was 0.90%. The uneven coating phenomenon disappeared, and the yield increased to 98%.

[0049] A comparison of the results of Example 4 and Example 3 shows that the polyether-modified cyclosiloxane softener used in this invention can further improve the film-forming effect compared with the polyethylene glycol softener, significantly reduce the broken fiber rate and fuzz rate of the finished product, and improve the yield.

[0050] Comparative Example 1

[0051] A method for preparing an electronic-grade industrial glass fiber yarn sizing agent, using a conventional small-molecule coupling agent as a bonding promoter, includes the following steps:

[0052] Take 100 parts by weight of waterborne polyurethane emulsion (same as in Example 1) and dilute it with 1.5 times the amount of deionized water. Then add 1.5 parts by weight of ethyl oleate lubricant, 0.75 parts by weight of AEO-7 emulsifier, 0.75 parts by weight of PEG-400 softener, 2.5 parts by weight of silane coupling agent γ-(methacryloyloxy)propyltrimethoxysilane (KH-570) and 16 parts by weight of deionized water, mix and homogenize to obtain the electronic grade industrial glass fiber yarn impregnating agent.

[0053] The initial viscosity of the sizing agent obtained in this comparative example was 3.5 cps, and the viscosity reached 29.8 cps after 48 hours of continuous operation, showing a significant increase from the start to the end of use. The film strength of the sizing agent, measured using a burst strength tester, was 410 kPa. The glass fiber breakage rate during fiber drawing was 9.60%, and the finished product hairiness rate was 11.86%. Significant uneven coating was observed, with a finished product yield of 75%.

[0054] A comparison of the results of Comparative Example 1 and Example 3 shows that the wetting agent formulation using the hydrolyzed emulsion of the macromolecular coupling agent of the present invention to replace the existing small molecule silane coupling agent can significantly improve the viscosity stability and coating effect of the wetting agent during application.

[0055] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing an electronic-grade industrial glass fiber yarn impregnating agent, characterized in that: Includes the following steps: (1) Preparation of macromolecular coupling agent: HTPB and hydrogen-containing silane coupling agent are dissolved in toluene, chloroplatinic acid catalyst is added and heated to catalyze the reaction to obtain hydroxyl-terminated polybutadiene containing coupling groups; diisocyanate is then added and the reaction is continued at a constant temperature. After the reaction is completed, the solvent is removed by drying to obtain a macromolecular coupling agent with a polyurethane structure. (2) Preparation of macromolecular coupling agent hydrolyzed emulsion: Prepare an acetic acid aqueous solution with a pH of 4~5, then add emulsifier and softener and stir to dissolve, then add the polyurethane structure macromolecular coupling agent obtained in step (1) and heat and stir to carry out hydrolysis reaction to obtain macromolecular coupling agent hydrolyzed emulsion. (3) Preparation of sizing agent: dilute water-based polyurethane emulsion, then add lubricant and hydrolyzed emulsion of macromolecular coupling agent obtained in step (2), mix and homogenize to obtain the electronic grade industrial glass fiber yarn sizing agent; The hydrogen-containing silane coupling agent mentioned in step (1) is trimethoxysilane or triethoxysilane; The softener mentioned in step (2) is polyethylene glycol or polyether-modified cyclosiloxane.

2. The method for preparing an electronic-grade industrial glass fiber yarn sizing agent according to claim 1, characterized in that: The HTPB has a hydroxyl value of 0.6~2.0 mmol / g and a 1,2-vinyl structure content of >20%.

3. The method for preparing an electronic-grade industrial glass fiber yarn impregnating agent according to claim 1, characterized in that: The amount of the hydrogen-containing silane coupling agent added is 5% to 40% of the mass of HTPB.

4. The method for preparing an electronic-grade industrial glass fiber yarn sizing agent according to claim 1, characterized in that: The temperature of the heating catalytic reaction is 70~90℃, and the time is 3~6h.

5. The method for preparing an electronic-grade industrial glass fiber yarn sizing agent according to claim 1, characterized in that: The diisocyanate is any one of isophorone diisocyanate, diphenylmethane diisocyanate, and toluene diisocyanate, and the molar ratio of diisocyanate to HTPB is 0.5~0.7:

1.

6. The method for preparing an electronic-grade industrial glass fiber yarn sizing agent according to claim 1, characterized in that: The emulsifier is any one of fatty alcohol polyoxyethylene ether and alkylphenol polyoxyethylene ether.

7. The method for preparing an electronic-grade industrial glass fiber yarn impregnating agent according to claim 1, characterized in that: The fabric softener is a polyether-modified cyclosiloxane fabric softener, and the preparation method of the polyether-modified cyclosiloxane fabric softener is as follows: D4H and allyl polyethylene glycol were dissolved in toluene at a molar ratio of 1:2~4, and chloroplatinic acid catalyst was added and heated to catalyze the reaction, thus obtaining a polyether-modified cyclosiloxane softener.

8. The method for preparing an electronic-grade industrial glass fiber yarn sizing agent according to claim 1, characterized in that: In the preparation steps of the macromolecular coupling agent hydrolyzed emulsion, the mass ratio of emulsifier, softener and polyurethane-structured macromolecular coupling agent added is 0.3~0.6:0.2~0.4:1; the solid content of the macromolecular coupling agent hydrolyzed emulsion is 20%~40%.

9. The method for preparing an electronic-grade industrial glass fiber yarn sizing agent according to claim 1, characterized in that: In the preparation step of the wetting agent, the aqueous polyurethane emulsion is diluted to a solid content of 6% to 15%; the lubricant is a fatty acid ester lubricant, and the amount of lubricant added is 2% to 6% of the solid content of the aqueous polyurethane emulsion; the amount of the hydrolyzed emulsion of the macromolecular coupling agent added is 5% to 20% of the solid content of the aqueous polyurethane emulsion.

10. An electronic-grade industrial glass fiber yarn impregnating agent, characterized in that, It is prepared by the method described in any one of claims 1 to 9.