CN118290033A - Preparation method of T-shaped glass fiber and high-strength transparent composite material thereof - Google Patents

Abstract

The invention relates to a method for preparing a T-glass fiber and a high-strength transparent composite material thereof. Based on the total amount of all glass raw materials in the T-glass fiber, the T-glass fiber includes the following glass raw material components by mass percentage: _SiO2 66-72%, _{Al2O3 0-7} %, _K2O and _Na2O total 10-12%, CaO and MgO total 10-14%, _La2O3 0-3%, _{B2O3 0-3} %; after the uniformly mixed glass raw materials are melted, they are drawn through a platinum-rhodium alloy plate to obtain the T-glass fiber; after the T-glass fiber _is coated with a wetting agent to prepare glass fiber yarn, the yarn is wound into spindles and woven into glass fiber fabric, and then compounded with epoxy resin to obtain the high-strength transparent composite material. The T-glass fiber of the invention has a lower refractive index; the preparation method is simple; and the preparation method of the high-strength transparent composite material can ensure high tensile strength and high transmittance.

Description

A method for preparing T-shaped glass fiber and high-strength transparent composite material thereof

Technical Field

The invention belongs to the technical field of resin-based composite materials and relates to a preparation method of a T-shaped glass fiber and a high-strength transparent composite material thereof.

Background technique

Resin-based glass fiber reinforced composites (GFRP), commonly known as glass fiber reinforced plastics, have good mechanical, chemical and heat resistance properties and are widely used in various structural reinforcement materials, such as the frame structure of vehicles such as automobiles, aircraft and high-speed railways, the shell of electronic devices such as mobile phones and televisions, photovoltaics, wind power, etc. However, the currently known glass fiber composite materials are all white, or colorants are added to the resin to form various colors. If the resin-based composite material can be made as highly transparent as organic glass and have both the mechanical and chemical properties of the composite material, it will have a wide range of uses in various structures.

In the prior art, glass fiber reinforced resin has poor transparency. The main reasons are as follows: the refractive index of glass fiber does not match that of the resin base; when light enters from one medium (such as glass fiber) into another medium (such as resin), if the refractive index of the two media does not match, the light will be reflected and refracted at the interface and cannot pass smoothly. For example, if light enters glass from air, the surface reflectivity calculation formula is as shown in formula (1);

R = (n _glass - n _air ) ² / (n _glass and n _air ) ² (1);

The refractive index of ordinary flat glass, _nglass , is 1.50, and _nair is 1, so the reflectivity of one surface reaches 4%; the glass transmittance test is for the front and back glass surfaces of the glass sheet, so the total reflectivity is 8%. The national standard GB 11614-2022 "Flat Glass" introduces formula (2) to calculate the transmittance of glass of different thicknesses;

T ₂ =92(T ₁ /92) ^(D ₂ ^/D ₁ ⁾ (2);

Wherein, _T1 is the transmittance of the sample, unit: %; _T2 is the transmittance converted to _D2 thickness, unit: %; _D1 is the sample thickness, unit: mm;

If it is ordinary E glass fiber, its refractive index is 1.56, and its single surface reflectivity R will reach 4.79%, then the total transmittance of the double-sided glass sheet is only 90.43%.

In order to increase the refractive index of the resin matrix, additional groups need to be introduced, so the aging resistance is poor; in the production process of glass fiber, in order to improve the wettability and adhesion between the fiber and the resin, a layer of sizing agent is usually applied. However, this layer of sizing agent is difficult to completely remove when preparing GFRP, and an interface will be formed between the fiber and the resin. This interface will not only affect the adhesion between the fiber and the resin, but also have a negative impact on the transmittance of light. Light may be scattered or reflected when passing through this interface, thereby reducing the transparency of GFRP.

Some studies have attempted to solve the problem of poor transparency of glass fiber reinforced resin. For example, CN201310566036.1 discloses a transparent glass fiber reinforced polypropylene composite material and a preparation method thereof, wherein the transparent composite material is prepared by adding 5-25% glass fiber, but the transmittance thereof does not exceed 80%, and when the glass fiber content reaches 25%, the tensile strength is 70 MPa and the transmittance is only 65%, which means that the tensile strength cannot be high while having a high transmittance.

CN201810057510.0 discloses a transparent core rod of a fiber-reinforced resin-based composite material for overhead conductors and its preparation process. The patent utilizes carbon fiber and glass fiber to composite and prepare a transparent core rod with a thermosetting resin. The patent does not explicitly mention transparency, but the carbon fiber is black and its transparency is limited.

CN202311726012.8 discloses a high-transmittance glass fiber reinforced epoxy resin composite material and a preparation method thereof, which utilizes E glass fiber or S glass fiber to achieve high-transmittance glass fiber reinforcement, uses epoxy resin as a matrix, and is coated with a commercial fiber bundle after being treated with a wetting agent, and a glass fiber with a mass fraction of 30 to 70% is added. The thickness of the prepared transparent composite material is only 0.40 mm. Based on its transmittance of 88.9%, the transmittance converted to 2 mm is only 77.5%.

Therefore, it is of great significance to try to solve the problem in the prior art that glass fiber resin composite materials cannot have high tensile strength and high transmittance at the same time.

Summary of the invention

The purpose of the present invention is to solve the problems existing in the prior art and provide a method for preparing a T-shaped glass fiber and a high-strength transparent composite material thereof.

To achieve the above object, the technical solution adopted by the present invention is as follows:

A T-glass fiber, based on the total amount of all glass raw materials in the T-glass fiber, the T-glass fiber comprises the following glass raw material components in terms of mass percentage:

SiO ₂ 66~72%;

Al ₂ O ₃ 0~7%;

Total amount of K ₂ O and Na ₂ O 10~12%;

Total amount of CaO and MgO 10~14%;

La ₂ O ₃ 0~3%;

B ₂ O ₃ 1~4%;

The total content (mass percentage) of Fe ₂ O ₃ impurities in the glass raw material is ≤0.01%;

SiO ₂ 66~72%, mainly provides the tetrahedral network structure of T-type glass fiber, ensuring that the glass has good heat resistance and stability, as well as lower melting temperature and molding operability.

Al ₂ O ₃ 0~7%, mainly provides chemical stability for T-type glass fiber, and is used in conjunction with SiO ₂ to reduce the crystallization tendency of glass, increase the fiber drawing window, improve the pass rate, and play a significant role in improving strength.

The total amount of K ₂ O and Na ₂ O is 10~12%. They are flux for T-glass fibers. While lowering the melting temperature, they can also increase the conductivity of T-glass fibers. In order to lower the dielectric constant, the total content of K ₂ O and Na ₂ O should not exceed 12%. K ₂ O can improve the transmittance and refractive index.

The total amount of CaO and MgO is 10~14%. Due to the limited alkali metal content, in order to further reduce the melting temperature, alkaline earth metal oxides are added to assist melting. At the same time, MgO can also increase the strength of the glass network and improve the mechanical properties of the glass fiber. MgO has a good regulating effect on improving the strength of T-glass fiber.

La ₂ O ₃ 0~3%. This oxide is mainly used to adjust the refractive index of T-type glass fiber. Since the matching of the refractive index directly affects the transmittance of the high-strength transparent composite material, the precise adjustment of the refractive index is achieved by fine-tuning the La ₂ O ₃ content.

B ₂ O ₃ 1~4%, boron oxide has the effect of further reducing the melting temperature, improving the heat resistance of glass fiber, and reducing the refractive index of glass. It plays a significant role in adjusting the refractive index and melting temperature.

The total content of Fe ₂ O ₃ impurities in glass raw materials is ≤ 0.01%. The content of Fe ₂ O ₃ is strictly controlled in order to reduce the absorption coefficient of glass to visible light and ultraviolet light.

The refractive index of the T-type glass fiber is 1.502-1.512.

As the preferred technical solution:

The T-glass fiber as described above, based on the total amount of all glass raw materials in the T-glass fiber, the T-glass fiber includes the following glass raw material components in terms of mass percentage:

SiO ₂ 68%;

Al ₂ O ₃ 6%;

Total amount of K ₂ O and Na ₂ O 11%;

Total amount of CaO and MgO 13%;

La ₂ O ₃ 1%;

B ₂ O ₃ 1%;

The total content of Fe ₂ O ₃ impurities in the glass raw materials is 0.006%.

The T-glass fiber as described above, based on the total amount of all glass raw materials in the T-glass fiber, the T-glass fiber includes the following glass raw material components in terms of mass percentage:

SiO ₂ 72%;

Al ₂ O ₃ 1%

Total amount of K ₂ O and Na ₂ O 11%;

Total amount of CaO and MgO 13%;

B ₂ O ₃ 3%;

The total content of Fe ₂ O ₃ impurities in the glass raw materials is 0.08%.

The present invention also provides a method for preparing a T-shaped glass fiber as described in any of the above items, wherein the uniformly mixed glass raw materials are melted at 1450-1550° C. for 3-4 hours and then drawn through a platinum-rhodium alloy bushing to obtain the T-shaped glass fiber.

The present invention also provides a method for preparing a high-strength transparent composite material, comprising coating the T-shaped glass fiber as described in any one of the above items with a sizing agent to prepare a glass fiber yarn, winding the glass fiber yarn into spindles and weaving it into a glass fiber fabric with a thickness of 20 to 50 microns, and then compounding it with an epoxy resin to obtain a high-strength transparent composite material;

The impregnating agent is an epoxy resin with a refractive index of 1.502 to 1.512;

The high-strength transparent composite material has a thickness of 2 mm, a tensile strength of more than 250 MPa, and a transmittance of more than 85%.

As the preferred technical solution:

In the method for preparing a high-strength transparent composite material as described above, the coating amount of the wetting agent is 0.1-0.5wt%.

In the method for preparing a high-strength transparent composite material as described above, the proportion of glass fiber fabric in the high-strength transparent composite material is 10-50wt%.

Principle of the invention:

The iron element in traditional glass fiber affects the transmittance. The present invention improves the transmittance of glass fiber by reducing the content of iron impurities. According to the definition in the ultra-white float glass industry standard JC/T 2128-2012: the content of _Fe2O3 in the composition is not more than 0.015%. In order to prepare high-transmittance T-type glass fiber, the present invention needs to strictly control _{the content of Fe2O3 in} the raw materials, so the total content of _{Fe2O3 impurities} in the glass raw materials is controlled to be _≤0.01 %.

Glass fiber yarns will refraction due to different refractive indices. The present invention uses a sizing agent with almost the same refractive index as the T-type glass fiber, so that the refractive indices of the prepared glass fiber yarns are the same, thereby reducing refraction.

Due to the different refractive indices between the glass fiber yarn and the resin matrix, reflection and refraction will also occur. The present invention eliminates reflection and refraction by ensuring that the refractive indices between them are substantially the same, thereby further improving transparency.

The wetting agent in the fiber yarn in the traditional transparent composite material is not removed cleanly or cannot be removed, resulting in light reflection and loss. The present invention avoids this problem by using a wetting agent with the same refractive index because the wetting agent does not need to be removed.

The refractive index of the T-shaped glass fiber of the present invention is 1.502-1.512, which is lower than 1.54-1.57 of common glass fiber, so it is easier to match with resins with the same refractive index, improves the stability of the composite material, and reduces the yellowing phenomenon.

In summary, the high-strength transparent composite material prepared in the present invention has a transmittance of more than 85% while ensuring a tensile strength of more than 250 MPa.

Beneficial effects:

(1) A T-type glass fiber of the present invention, wherein the total content of Fe ₂ O ₃ impurities in the glass raw material is ≤0.01%, so that the T-type glass fiber has a lower refractive index and a higher transmittance;

(2) The method for preparing T-shaped glass fiber of the present invention has a simple process and is easy to operate;

(3) A method for preparing a high-strength transparent composite material of the present invention uses a sizing agent having the same refractive index as the T-glass fiber, so that the refractive index between the glass fiber yarns is the same, reducing refraction, and there is no need to remove the sizing agent, thereby simplifying the preparation process and making the high-strength transparent composite material have good stability and yellowing resistance;

(4) The method for preparing a high-strength transparent composite material of the present invention significantly improves the optical properties while ensuring the mechanical properties. The prepared high-strength transparent composite material can ensure that the tensile strength is above 250 MPa and the transmittance reaches above 85%.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a transmittance curve of high-strength transparent composite materials of Examples 6 to 10; wherein T1 is Example 6, T2 is Example 7, T3 is Example 8, T4 is Example 9, and T5 is Example 10.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

The test methods involved in the performance indicators in the embodiments and comparative examples of the present invention are as follows:

Glass fiber density: refer to GB/T 5432-2008 "Determination of glass density by buoyancy method".

Glass fiber refractive index: refer to GB/T 7962.1-2010 Test method for colorless optical glass Part 1: Refractive index and dispersion coefficient.

Glass fiber transmittance: Refer to GB/T 7962.12-2010 Test method for colorless optical glass Part 12: Spectral transmittance, and measure the average transmittance in the visible light band in the GB/T 2680-2021 standard.

Glass fiber tensile strength: refer to GB/T 31290-2022 Determination of tensile properties of carbon fiber monofilament.

Glass fiber elastic modulus: refer to GB/T 31290-2022 Determination of tensile properties of carbon fiber monofilament.

Composite material tensile strength: refer to GB/T 1447-2005 Test method for tensile properties of fiber reinforced plastics.

Composite material transmittance: Refer to GB/T 2410-2008 Determination of light transmittance and haze of transparent plastics, and measure the average transmittance in the visible light band in GB/T2680-2021 standard.

Example 1

A method for preparing T-shaped glass fiber, the specific steps are as follows:

(1) Based on the total amount of all glass raw materials in T-glass fiber, calculated by mass percentage, T-glass fiber includes the following glass raw material components:

SiO ₂ 68%;

Al ₂ O ₃ 6%;

_K2O 1%;

_Na2O 10%;

CaO 10%;

MgO 3%;

La ₂ O ₃ 1%;

B ₂ O ₃ 1%;

The total content of Fe ₂ O ₃ impurities in the glass raw materials is 0.006%;

(2) After the uniformly mixed glass raw materials are melted at 1480°C for 4 hours, they are drawn through a platinum-rhodium alloy wire drawing plate to produce T-shaped glass fibers.

The refractive index of the prepared T-glass fiber is 1.508.

Example 2

A method for preparing T-shaped glass fiber, the specific steps are as follows:

(1) Based on the total amount of all glass raw materials in T-glass fiber, calculated by mass percentage, T-glass fiber includes the following glass raw material components:

SiO ₂ 68%;

Al ₂ O ₃ 5%;

_Na2O 10%;

CaO 12%;

La ₂ O ₃ 3%;

B ₂ O ₃ 2%;

The total content of Fe ₂ O ₃ impurities in the glass raw materials is 0.008%;

(2) After the uniformly mixed glass raw materials are melted at 1530°C for 3.5 hours, they are drawn through a platinum-rhodium alloy filter plate to produce T-shaped glass fibers.

The refractive index of the prepared T-glass fiber is 1.511.

Example 3

A method for preparing T-shaped glass fiber, the specific steps are as follows:

(1) Based on the total amount of all glass raw materials in T-glass fiber, calculated by mass percentage, T-glass fiber includes the following glass raw material components:

SiO ₂ 72%;

Al ₂ O ₃ 1%;

_K2O 1%;

_Na2O 10%;

CaO 8%;

MgO 5%;

B ₂ O ₃ 3%;

The total content of Fe ₂ O ₃ impurities in the glass raw materials is 0.008%;

(2) After the uniformly mixed glass raw materials are melted at 1520°C for 3 hours, they are drawn through a platinum-rhodium alloy wire drawing plate to produce T-shaped glass fibers.

The refractive index of the prepared T-glass fiber is 1.502.

Comparative Example 1

A method for preparing an E-glass fiber is basically the same as that of Example 3, except that the E-glass fiber includes the following glass raw material components, calculated by mass percentage, based on the total amount of all glass raw materials in the E-glass fiber:

SiO ₂ 54%;

Al ₂ O ₃ 16%;

_Na2O 0.5%;

CaO 17%;

MgO 4.4%;

B ₂ O ₃ 8%;

Fe ₂ O ₃ 0.1%.

The refractive index of the prepared E-type glass fiber is 1.560, and the internal transmittance is only 92%.

Comparing Comparative Example 1 with Example 3, it can be found that the E-type glass fiber has a high refractive index and a low internal transmittance. This is because the raw material of the E-type glass fiber contains a small amount of Fe ₂ O ₃ . After being made into glass fiber, the light is scattered due to the reduced diameter, so it appears grayish white and has a low internal transmittance.

Example 4

A method for preparing T-shaped glass fiber, the specific steps are as follows:

(1) Based on the total amount of all glass raw materials in T-glass fiber, calculated by mass percentage, T-glass fiber includes the following glass raw material components:

SiO ₂ 70%;

Al ₂ O ₃ 1%;

_Na2O 12%;

CaO 10%;

MgO 2%;

La ₂ O ₃ 1%;

B ₂ O ₃ 4%;

The total content of Fe ₂ O ₃ impurities in the glass raw materials is 0.008%;

(2) After the uniformly mixed glass raw materials are melted at 1550°C for 3 hours, they are drawn through a platinum-rhodium alloy wire drawing plate to produce T-shaped glass fibers.

The refractive index of the prepared T-glass fiber is 1.506.

Example 5

A method for preparing T-shaped glass fiber, the specific steps are as follows:

(1) Based on the total amount of all glass raw materials in T-glass fiber, calculated by mass percentage, T-glass fiber includes the following glass raw material components:

SiO ₂ 66%;

Al ₂ O ₃ 7%;

_Na2O 10%;

CaO 11%;

MgO 2%;

La ₂ O ₃ 1.0 % ;

B ₂ O ₃ 3%;

The total content of Fe ₂ O ₃ impurities in the glass raw materials is 0.009%;

(2) After the uniformly mixed glass raw materials are melted at 1450°C for 4 hours, they are drawn through a platinum-rhodium alloy wire drawing plate to produce T-shaped glass fibers.

The refractive index of the prepared T-glass fiber is 1.504.

The detailed performance data of Examples 1 to 5 are shown in Table 1:

Table 1

Example 1 Example 2 Example 3 Example 4 Example 5 Glass fiber density/g.cm ^-3 2.512 2.521 2.506 2.516 2.518 Glass fiber refractive index/% 1.508 1.511 1.502 1.506 1.504 Transmission rate in glass fiber/% 99% 99% 99% 99% 99% Glass fiber tensile strength/MPa 1268 1524 1366 1380 1257 Glass fiber elastic modulus/GPa 72 76 71 72 75

Example 6

A method for preparing a high-strength transparent composite material, the specific steps are as follows:

(1) Preparation of raw materials:

The T-glass fiber of Example 1;

Sizing agent: A composite epoxy resin with a refractive index of 1.508 is prepared by mixing two hydrogenated bisphenol A epoxy resins I102215 and P464946 in a mass ratio of 45:55. The manufacturer of I102215 and P464946 is Shanghai Aladdin Biochemical Technology Co., Ltd., CAS: 80-04-6;

Epoxy resin: A composite epoxy resin with a refractive index of 1.508 was prepared by mixing two hydrogenated bisphenol A epoxy resins, I102215 and P464946, in a mass ratio of 45:55. The manufacturer of I102215 and P464946 is Shanghai Aladdin Biochemical Technology Co., Ltd., CAS: 80-04-6;

(2) coating T-shaped glass fibers with a sizing agent to prepare glass fiber yarns, winding the glass fiber yarns into spindles to weave glass fiber fabrics with a thickness of 35 μm, and then compounding with epoxy resin to obtain a high-strength transparent composite material;

The coating amount of the wetting agent is 0.15wt%; the proportion of the glass fiber fabric in the high-strength transparent composite material is 20wt%.

The final high-strength transparent composite material has a thickness of 2 mm, a tensile strength of 286 MPa, and a transmittance of 86.6%.

Example 7

A method for preparing a high-strength transparent composite material, the specific steps are as follows:

(1) Preparation of raw materials:

The T-glass fiber of Example 2;

Sizing agent: A composite epoxy resin with a refractive index of 1.511 is prepared by mixing two hydrogenated bisphenol A epoxy resins I102215 and P464946 in a mass ratio of 24:76. The manufacturer of I102215 and P464946 is Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No.: 80-04-6;

Epoxy resin: A composite epoxy resin with a refractive index of 1.511 was prepared by mixing two hydrogenated bisphenol A epoxy resins, I102215 and P464946, in a mass ratio of 24:76. The manufacturer of I102215 and P464946 is Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No.: 80-04-6;

(2) coating T-shaped glass fibers with a sizing agent to prepare glass fiber yarns, winding the glass fiber yarns into spindles to weave glass fiber fabrics with a thickness of 50 μm, and then compounding with epoxy resin to obtain a high-strength transparent composite material;

The coating amount of the wetting agent is 0.1wt%; the proportion of the glass fiber fabric in the high-strength transparent composite material is 25wt%.

The high-strength transparent composite material finally obtained has a thickness of 2 mm, a tensile strength of 269 MPa, as shown in FIG1 , and a transmittance of 87.4%.

Example 8

A method for preparing a high-strength transparent composite material, the specific steps are as follows:

(1) Preparation of raw materials:

The T-glass fiber of Example 3;

Sizing agent: A composite epoxy resin with a refractive index of 1.502 is prepared by mixing two hydrogenated bisphenol A epoxy resins I102215 and P464946 in a mass ratio of 76:24. The manufacturer of I102215 and P464946 is Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No.: 80-04-6;

Epoxy resin: A composite epoxy resin with a refractive index of 1.502 was prepared by mixing two hydrogenated bisphenol A epoxy resins, I102215 and P464946, in a mass ratio of 76:24. The manufacturer of I102215 and P464946 is Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No.: 80-04-6;

(2) coating T-shaped glass fibers with a sizing agent to prepare glass fiber yarns, winding the glass fiber yarns into spindles to weave glass fiber fabrics with a thickness of 30 μm, and then compounding with epoxy resin to obtain high-strength transparent composite materials;

The coating amount of the wetting agent is 0.3wt%; the proportion of the glass fiber fabric in the high-strength transparent composite material is 30wt%.

The high-strength transparent composite material finally obtained has a thickness of 2 mm, a tensile strength of 275 MPa, as shown in FIG1 , and a transmittance of 86.2%.

Comparative Example 2

A method for preparing a transparent composite material is basically the same as that of Example 8, except that the T-type glass fiber is replaced by the E-type glass fiber of Comparative Example 1.

The prepared transparent composite material has a thickness of 2 mm, a tensile strength of 234 MPa, and a transmittance of 58.4%.

Comparing Comparative Example 2 with Example 8, it can be found that the optical transmittance of Comparative Example 2 is significantly reduced, from 86.2% to 58.4%. This is because the glass fiber in Comparative Example 2 contains more _{Fe2O3 ,} which absorbs visible light. At the same time, due to the different components, the refractive index of the glass fiber is different. The refractive index of the glass fiber and the resin in Comparative Example 2 is quite different, and the interface reflection loss between the glass fiber and the resin is relatively large. It also causes light scattering, and the scattered light further reduces the glass transmittance.

Comparative Example 3

A method for preparing a transparent composite material is basically the same as Example 8, except that the wetting agent is a composite epoxy resin with a refractive index of 1.544 compounded by hydrogenated bisphenol A epoxy resin (P464946, manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., CAS No.: 80-04-6) and bisphenol A type epoxy resin (E-03 type, manufacturer: Hubei Xinkang Pharmaceutical Chemical Co., Ltd., CAS No.: 25085-99-8) in a mass ratio of 30:70.

The thickness of the prepared transparent composite material is 2 mm, the tensile strength is 215 MPa, and the transmittance is 63.6%.

By comparing Comparative Example 3 with Example 8, it can be found that the tensile strength of the composite material of Comparative Example 3 is reduced, the optical transmittance is significantly reduced, and the obvious texture of the glass fiber fabric can still be seen. This is due to three factors: 1. Since the refractive index of the impregnating agent coated on the glass fiber is inconsistent with that of the matrix resin, the light is distorted, so the texture of the surface fabric of the composite material can be clearly seen; 2. Due to the difference between the two resins, the matrix resin and the fiber fabric are not tightly combined, so the tensile performance is reduced; 3. Since the refractive index of the glass fiber and the matrix resin is different, multiple interfaces are generated. On the one hand, each interface has reflection, and on the other hand, each interface will also produce refraction and scattering, which will significantly reduce the transmittance of the composite material.

Example 9

A method for preparing a high-strength transparent composite material, the specific steps are as follows:

(1) Preparation of raw materials:

The T-glass fiber of Example 4;

Sizing agent: A composite epoxy resin with a refractive index of 1.506 is prepared by mixing two hydrogenated bisphenol A epoxy resins I102215 and P464946 in a mass ratio of 40:60. The manufacturer of I102215 and P464946 is Shanghai Aladdin Biochemical Technology Co., Ltd., CAS: 80-04-6;

Epoxy resin: A composite epoxy resin with a refractive index of 1.506 was prepared by mixing two hydrogenated bisphenol A epoxy resins, I102215 and P464946, in a mass ratio of 40:60. The manufacturer of I102215 and P464946 is Shanghai Aladdin Biochemical Technology Co., Ltd., CAS: 80-04-6;

(2) coating T-shaped glass fibers with a sizing agent to prepare glass fiber yarns, winding the glass fiber yarns into spindles to weave glass fiber fabrics with a thickness of 25 μm, and then compounding with epoxy resin to obtain a high-strength transparent composite material;

The coating amount of the wetting agent is 0.2wt%; the proportion of the glass fiber fabric in the high-strength transparent composite material is 10 wt%.

The high-strength transparent composite material finally obtained has a thickness of 2 mm, a tensile strength of 256 MPa, as shown in FIG1 , and a transmittance of 88.2%.

Example 10

A method for preparing a high-strength transparent composite material, the specific steps are as follows:

(1) Preparation of raw materials:

The T-glass fiber of Example 5;

Sizing agent: A composite epoxy resin with a refractive index of 1.504 was prepared by mixing two hydrogenated bisphenol A epoxy resins I102215 and P464946 in a mass ratio of 32:68. The manufacturer of I102215 and P464946 is Shanghai Aladdin Biochemical Technology Co., Ltd., CAS: 80-04-6;

Epoxy resin: A composite epoxy resin with a refractive index of 1.504 was prepared by mixing two hydrogenated bisphenol A epoxy resins, I102215 and P464946, in a mass ratio of 32:68. The manufacturer of I102215 and P464946 is Shanghai Aladdin Biochemical Technology Co., Ltd., CAS: 80-04-6;

(2) coating T-shaped glass fibers with a sizing agent to prepare glass fiber yarns, winding the glass fiber yarns into spindles to weave glass fiber fabrics with a thickness of 50 μm, and then compounding with epoxy resin to obtain a high-strength transparent composite material;

The coating amount of the wetting agent is 0.5wt%; the proportion of the glass fiber fabric in the high-strength transparent composite material is 50 wt%.

The high-strength transparent composite material finally obtained has a thickness of 2 mm, a tensile strength of 266 MPa, as shown in FIG1 , and a transmittance of 85.8%.

Claims (7)

1. A T-glass fiber, characterized in that: based on the total amount of all glass raw materials in the T-shaped glass fiber, the T-shaped glass fiber comprises the following glass raw material components in percentage by mass:

SiO₂ 66~72%；

Al₂O₃ 0~7%；

10-12% of the total amount of K ₂ O and Na ₂ O;

10-14% of the total amount of CaO and MgO;

La₂O₃ 0~3%;B₂O₃ 1~4%；

The total content of Fe ₂O₃ impurities in the glass raw material is less than or equal to 0.01 percent;

The refractive index of the T-shaped glass fiber is 1.502-1.512.

2. A T-glass fiber according to claim 1, wherein the T-glass fiber comprises the following glass raw material components in mass percent based on the total amount of all glass raw materials in the T-glass fiber:

SiO2 68%；

Al2O3 6%

11% of the total amount of K ₂ O and Na ₂ O;

13% of the total amount of CaO and MgO;

La₂O₃ 1%；

B₂O₃ 1%；

the total content of Fe ₂O₃ impurities in the glass raw material is 0.006%.

3. A T-glass fiber according to claim 1, wherein the T-glass fiber comprises the following glass raw material components in mass percent based on the total amount of all glass raw materials in the T-glass fiber:

SiO₂ 72%；

Al₂O₃ 1%；

11% of the total amount of K ₂ O and Na ₂ O;

13% of the total amount of CaO and MgO;

B₂O₃ 3%；

the total content of Fe ₂O₃ impurities in the glass raw material is 0.008%.

4. A method for preparing a T-glass fiber according to any one of claims 1 to 3, wherein: and melting the uniformly mixed glass raw materials at 1450-1550 ℃ for 3-4 hours, and drawing wires through a platinum-rhodium alloy bushing plate to obtain the T-shaped glass fiber.

5. A preparation method of a high-strength transparent composite material is characterized by comprising the following steps: preparing glass fiber yarns after coating the impregnating compound on the T-shaped glass fibers according to any one of claims 1-3, and weaving the glass fiber yarns into glass fiber fabrics with the thickness of 20-50 microns by winding, and then compounding the glass fiber fabrics with epoxy resin to prepare a high-strength transparent composite material;

the impregnating compound is epoxy resin with the refractive index of 1.502-1.512;

the thickness of the high-strength transparent composite material is 2mm, the tensile strength is more than 250MPa, and the transmittance is more than 85%.

6. The method for preparing a high-strength transparent composite material according to claim 5, wherein the coating amount of the impregnating compound is 0.1-0.5wt%.

7. The method for preparing the high-strength transparent composite material according to claim 5, wherein the glass fiber fabric in the high-strength transparent composite material accounts for 10-50wt%.