阅读说明：本技术 一种透明阻燃耐热有机玻璃板及其制备方法 (Transparent flame-retardant heat-resistant organic glass plate and preparation method thereof ) 是由 田统帅 周小二 邹毅 于 2020-12-03 设计创作，主要内容包括：本发明涉及一种透明阻燃耐热有机玻璃板及其制备方法,该透明阻燃耐热有机玻璃板由以下重量份配比的原料制成：甲基丙烯酸甲酯90-120份、甲基丙烯酸1-10份、阻燃剂15-30份、偶氮二异丁腈0.001-0.01份、硬脂酸0.1-5份、交联剂1-10份。与现有技术相比,本发明制备的透明阻燃耐热有机玻璃板不仅具有阻燃性能优良的特点,此外还具有优异的透光性、较高的热变形温度,由此拓宽了有机玻璃板材的应用领域及使用价值。(The invention relates to a transparent flame-retardant heat-resistant organic glass plate and a preparation method thereof, wherein the transparent flame-retardant heat-resistant organic glass plate is prepared from the following raw materials in parts by weight: 90-120 parts of methyl methacrylate, 1-10 parts of methacrylic acid, 15-30 parts of a flame retardant, 0.001-0.01 part of azobisisobutyronitrile, 0.1-5 parts of stearic acid and 1-10 parts of a cross-linking agent. Compared with the prior art, the transparent flame-retardant heat-resistant organic glass plate prepared by the invention has the characteristic of excellent flame-retardant performance, and also has excellent light transmittance and higher heat distortion temperature, so that the application field and the use value of the organic glass plate are expanded.)

1. A transparent flame-retardant heat-resistant organic glass plate is characterized by being prepared from the following raw materials in parts by weight:

2. the transparent flame-retardant heat-resistant organic glass sheet according to claim 1, wherein the flame retardant is a mixture of halogenated phosphate and dimethyl methylphosphonate.

3. The transparent flame-retardant heat-resistant organic glass plate as claimed in claim 2, wherein the mass ratio of the halogenated phosphate to the dimethyl methylphosphonate is 1: 1-5: 1.

4. A transparent fire retardant and heat resistant plastic glazing panel as claimed in claim 2 or claim 3 wherein the halogenated phosphate esters comprise tris (2-chloropropyl) phosphate, tris (2-chloroethyl) phosphate, tris (1,3 dichloropropyl) phosphate.

5. The transparent flame-retardant heat-resistant organic glass plate as claimed in claim 1, wherein the cross-linking agent is one or more of acrylic esters such as acrylic methacrylate, ethylene glycol methacrylate, butylene glycol diacrylate and the like.

6. The method for preparing a transparent flame-retardant heat-resistant organic glass plate according to any one of claims 1 to 5, wherein the transparent flame-retardant heat-resistant organic glass plate is prepared by the following steps:

(5) taking methyl methacrylate, methacrylic acid and an initiator azobisisobutyronitrile according to the proportion, stirring and heating until the mixture is boiled; then stopping heating, keeping the temperature and stirring to obtain a system, and taking out the system to cool to room temperature after the system reaches the required viscosity;

(6) adding a cross-linking agent, an initiator azodiisobutyronitrile, a flame retardant and a release agent into the system according to the proportion, uniformly stirring and defoaming in vacuum to obtain a pre-polymerization material;

(7) metering the pre-polymerized material, filling the pre-polymerized material into a glass mold, exhausting gas, and clamping by using a clamp;

(8) placing the glass mold filled with the materials in a water bath, maintaining the temperature of the water bath at 40-60 ℃, and reacting for 2-8 hours until the materials in the mold are completely hardened;

(5) and (3) placing the die into a drying room, and further curing for 1-3 hours at the high temperature of 80-130 ℃. And naturally cooling to room temperature, and removing the mold to obtain the transparent flame-retardant heat-resistant organic glass plate.

7. The method for preparing the transparent flame-retardant heat-resistant organic glass plate according to claim 6, wherein the specific process of vacuum defoaming in the step (2) is as follows:

firstly, putting a system added with a cross-linking agent, an initiator azodiisobutyronitrile, a flame retardant and a release agent into a closed container;

then stirring and adding a system of a cross-linking agent, an initiator azodiisobutyronitrile, a flame retardant and a release agent into the closed container, and exhausting air from the closed container to the outside in the stirring process until the air pressure in the closed container is less than a standard atmospheric pressure;

then keeping the air pressure in the closed container, standing for more than 5 minutes, and injecting air into the closed container at an air flow rate of less than 1L per hour until the air pressure in the closed container is consistent with the air pressure outside the closed container.

Technical Field

The invention relates to the technical field of organic glass, in particular to a transparent flame-retardant heat-resistant organic glass plate and a preparation method thereof.

Background

The organic glass has excellent optical and mechanical properties, but the polymethyl methacrylate has low limited oxygen index, poor flame retardant property, easy combustion and high heat release rate, thereby greatly limiting the application of the organic glass and being necessary to improve the flame retardant property of the organic glass. However, PMMA is a weak-polarity linear structure, the intermolecular force is weak, the main chain strength is low, the glass transition temperature of pure organic glass is 105 ℃, the maximum temperature of the pure organic glass for long-term use is 60 ℃, the pure organic glass is easy to bend and deform when being used at a higher temperature for a long time, in order to achieve a certain flame-retardant grade, 20-30% of flame retardant is often required to be introduced, the softening temperature of the organic glass is further reduced, and the use of the organic glass in a larger range is limited.

Patent CN110294814A and patent CN110294815A provide a transparent flame-retardant organic glass and a preparation method thereof, and the flame-retardant organic glass with excellent flame-retardant property is prepared by adopting phosphate and dimethyl methylphosphonate, but the softening temperature of the organic glass is further reduced, and the application of the organic glass in a wider range is limited.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a transparent flame-retardant heat-resistant organic glass plate and a preparation method thereof.

The invention solves the technical problems through the following technical means: a transparent flame-retardant heat-resistant organic glass plate is characterized by being prepared from the following raw materials in parts by weight:

further, the flame retardant is a mixture of halogenated phosphate and dimethyl methylphosphonate.

Further, the mass ratio of the halogenated phosphate to the dimethyl methylphosphonate is 1: 1-5: 1.

Further, the halogenated phosphate ester comprises phosphoric acid-tris (2-chloropropyl) ester, phosphoric acid-tris (2-chloroethyl) ester and phosphoric acid-tris (1, 3-dichloropropyl) ester.

Furthermore, the cross-linking agent is one or more of propylene esters such as methacrylic acid propylene ester, ethylene glycol methacrylate, butanediol diacrylate and the like.

The preparation method of the transparent flame-retardant heat-resistant organic glass plate comprises the following steps:

(1) taking methyl methacrylate, methacrylic acid and an initiator azobisisobutyronitrile according to the proportion, stirring and heating until the mixture is boiled; then stopping heating, keeping the temperature and stirring to obtain a system, and taking out the system to cool to room temperature after the system reaches the required viscosity;

(2) adding a cross-linking agent, an initiator azodiisobutyronitrile, a flame retardant and a release agent into the system according to the proportion, uniformly stirring and defoaming in vacuum to obtain a pre-polymerization material;

(3) metering the pre-polymerized material, filling the pre-polymerized material into a glass mold, exhausting gas, and clamping by using a clamp;

(4) placing the glass mold filled with the materials in a water bath, maintaining the temperature of the water bath at 40-60 ℃, and reacting for 2-8 hours until the materials in the mold are completely hardened;

(5) and (3) placing the die into a drying room, and further curing for 1-3 hours at the high temperature of 80-130 ℃. And naturally cooling to room temperature, and removing the mold to obtain the transparent flame-retardant heat-resistant organic glass plate.

Further, the specific process of vacuum defoaming in the step (2) is as follows:

firstly, putting a system added with a cross-linking agent, an initiator azodiisobutyronitrile, a flame retardant and a release agent into a closed container;

then stirring and adding a system of a cross-linking agent, an initiator azodiisobutyronitrile, a flame retardant and a release agent into the closed container, and exhausting air from the closed container to the outside in the stirring process until the air pressure in the closed container is less than a standard atmospheric pressure;

then keeping the air pressure in the closed container, standing for more than 5 minutes, and injecting air into the closed container at an air flow rate of less than 1L per hour until the air pressure in the closed container is consistent with the air pressure outside the closed container.

The invention has the advantages that: the halophosphate and dimethyl methylphosphonate were selected as flame retardants for organic glass because both compounds are colorless liquids and have good compatibility with MMA. And the refractive index is similar to that of PMMA, so that the transparency of the organic glass can be kept under the condition of achieving flame retardance.

Methacrylic acid with active hydrogen atoms can form hydrogen bonds with oxygen atoms on the carbonyl group of the substrate, so that the interaction force among polymer chains is enhanced. On the premise of not influencing the processing and shaping, the thermal deformation temperature of the organic glass is improved. And the methyl group of the methacrylic acid restricts the rotation of the main chain, and the glass transition temperature of the organic glass can be obviously improved. Therefore, the invention adopts methacrylic acid as a comonomer to improve the heat resistance of the flame-retardant organic glass.

The transparent flame-retardant heat-resistant organic glass plate prepared by the technical scheme has the characteristic of excellent flame-retardant property, and also has higher heat distortion temperature and transparency of not less than 90%, so that the application field and use value of the organic glass plate are widened.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

a transparent flame-retardant heat-resistant organic glass plate is prepared from the following raw materials in parts by weight: 100 parts of methyl methacrylate, 4 parts of methacrylic acid, 15 parts of tris (2-chloropropyl) phosphate, 10 parts of dimethyl methylphosphonate, 0.004 part of azobisisobutyronitrile, 3 parts of stearic acid and 2 parts of allyl methacrylate.

The preparation steps are as follows:

(1) 100 parts of methyl methacrylate, 4 parts of methacrylic acid and 0.004 part of azodiisobutyronitrile are uniformly mixed, stirred and heated to boiling, and then the heating is stopped and the stirring is kept at the temperature. Taking out the system after the viscosity of the system reaches 60-70s, and cooling to room temperature;

(2) adding 15 parts of tris (2-chloropropyl) phosphate, 10 parts of dimethyl methyl phosphonate, 0.003 part of azobisisobutyronitrile, 3 parts of stearic acid and 2 parts of allyl methacrylate, stirring uniformly, and vacuumizing to obtain a prepolymer;

metering the pre-polymerized material, filling the pre-polymerized material into a mold, exhausting gas, and clamping by using a clamp; the specific flow of gas removal is as follows: firstly, putting a system added with a cross-linking agent, an initiator azodiisobutyronitrile, a flame retardant and a release agent into a closed container; then stirring and adding a system of a cross-linking agent, an initiator azodiisobutyronitrile, a flame retardant and a release agent into the closed container, and exhausting air from the closed container to the outside in the stirring process until the air pressure in the closed container is less than a standard atmospheric pressure; then keeping the air pressure in the closed container, standing for more than 5 minutes, and injecting air into the closed container at an air flow rate of less than 1L per hour until the air pressure in the closed container is consistent with the air pressure outside the closed container;

(3) placing the glass mold filled with the materials in a water bath, maintaining the temperature of the water bath at 40 ℃, and reacting for 6 hours until the materials in the mold are completely hardened;

(4) the mould is placed into a drying room and is further cured for 2 hours at the high temperature of 110 ℃. And naturally cooling to room temperature, and removing the mold to obtain the transparent flame-retardant heat-resistant organic glass plate.

Example 2

A transparent flame-retardant heat-resistant organic glass plate is prepared from the following raw materials in parts by weight: 100 parts of methyl methacrylate, 3 parts of methacrylic acid, 20 parts of tris (1,3 dichloropropyl) phosphate, 15 parts of dimethyl methylphosphonate, 0.005 part of azobisisobutyronitrile, 5 parts of stearic acid and 3 parts of propylene methacrylate.

The preparation steps are as follows:

(1) 100 parts of methyl methacrylate, 3 parts of methacrylic acid and 0.005 part of azodiisobutyronitrile are uniformly mixed, stirred and heated to boiling, and then the heating is stopped and the stirring is kept at the temperature. Taking out the system after the system reaches the required viscosity and cooling to room temperature;

(2) adding 20 parts of tris (1, 3-dichloropropyl) phosphate, 15 parts of dimethyl methylphosphonate, 0.005 part of azobisisobutyronitrile, 5 parts of stearic acid and 3 parts of allyl methacrylate, stirring uniformly, and vacuumizing to obtain a prepolymer;

metering the pre-polymerized material, filling the pre-polymerized material into a mold, exhausting gas, and clamping by using a clamp; the specific flow of gas removal is as follows: firstly, putting a system added with a cross-linking agent, an initiator azodiisobutyronitrile, a flame retardant and a release agent into a closed container; then stirring and adding a system of a cross-linking agent, an initiator azodiisobutyronitrile, a flame retardant and a release agent into the closed container, and exhausting air from the closed container to the outside in the stirring process until the air pressure in the closed container is less than a standard atmospheric pressure; then keeping the air pressure in the closed container, standing for more than 5 minutes, and injecting air into the closed container at an air flow rate of less than 1L per hour until the air pressure in the closed container is consistent with the air pressure outside the closed container;

(3) placing the glass mold filled with the materials in a water bath, maintaining the temperature of the water bath at 50 ℃, and reacting for 4 hours until the materials in the mold are completely hardened;

(4) the mould is placed into a drying room and is further cured for 2 hours at the high temperature of 110 ℃. And naturally cooling to room temperature, and removing the mold to obtain the transparent flame-retardant heat-resistant organic glass plate.

Example 3

A transparent flame-retardant heat-resistant organic glass plate is prepared from the following raw materials in parts by weight: 100 parts of methyl methacrylate, 5 parts of methacrylic acid, 18 parts of tris (2-chloropropyl) phosphate, 10 parts of dimethyl methylphosphonate, 0.004 part of azobisisobutyronitrile, 3 parts of stearic acid and 1 part of ethylene glycol methacrylate.

The preparation steps are as follows:

(1) uniformly mixing 100 parts of methyl methacrylate, 5 parts of methacrylic acid and 0.004 part of azodiisobutyronitrile, stirring and heating to boil, then stopping heating, preserving heat and stirring. Taking out the system after the system reaches the required viscosity and cooling to room temperature;

(2) adding 18 parts of tris (2-chloropropyl) phosphate, 10 parts of dimethyl methyl phosphonate, 0.004 part of azobisisobutyronitrile, 3 parts of stearic acid and 1 part of ethylene glycol methacrylate, stirring uniformly, and vacuumizing to obtain a prepolymer;

metering the pre-polymerized material, filling the pre-polymerized material into a mold, exhausting gas, and clamping by using a clamp; the specific flow of gas removal is as follows: firstly, putting a system added with a cross-linking agent, an initiator azodiisobutyronitrile, a flame retardant and a release agent into a closed container; then stirring and adding a system of a cross-linking agent, an initiator azodiisobutyronitrile, a flame retardant and a release agent into the closed container, and exhausting air from the closed container to the outside in the stirring process until the air pressure in the closed container is less than a standard atmospheric pressure; then keeping the air pressure in the closed container, standing for more than 5 minutes, and injecting air into the closed container at an air flow rate of less than 1L per hour until the air pressure in the closed container is consistent with the air pressure outside the closed container;

(3) placing the glass mold filled with the materials in a water bath, maintaining the temperature of the water bath at 60 ℃, and reacting for 3 hours until the materials in the mold are completely hardened;

(4) the mould is placed into a drying room and is further cured for 3 hours at the high temperature of 110 ℃. And naturally cooling to room temperature, and removing the mold to obtain the transparent flame-retardant heat-resistant organic glass plate.

Comparative example

A transparent flame-retardant organic glass plate is prepared from the following raw materials in parts by weight: 100 parts of methyl methacrylate, 15 parts of tris (2-chloropropyl) phosphate, 10 parts of dimethyl methylphosphonate, 0.004 part of azobisisobutyronitrile and 3 parts of stearic acid.

The preparation steps are as follows:

(1) and (3) uniformly mixing 100 parts of methyl methacrylate and 0.004 part of azobisisobutyronitrile, stirring and heating until the mixture is boiled, then stopping heating, keeping the temperature and stirring. Taking out the system after the system reaches the required viscosity and cooling to room temperature;

(2) adding 15 parts of tris (2-chloropropyl) phosphate, 10 parts of dimethyl methylphosphonate, 0.004 parts of azobisisobutyronitrile and 3 parts of stearic acid, stirring uniformly, and vacuumizing to obtain a prepolymer;

(3) metering the pre-polymerized material, filling the pre-polymerized material into a mold, exhausting gas, and clamping by using a clamp;

(4) placing the glass mold filled with the materials in a water bath, maintaining the temperature of the water bath at 40 ℃, and reacting for 6 hours until the materials in the mold are completely hardened;

(5) the mould is placed into a drying room and is further cured for 2 hours at the high temperature of 110 ℃. And naturally cooling to room temperature, and removing the mold to obtain the transparent flame-retardant organic glass plate.

The transparent flame-retardant heat-resistant organic glass plates prepared in examples 1 to 3 and the transparent flame-retardant organic glass plate prepared in the comparative example were subjected to performance tests, and the test results are shown in the following table:

the test result shows that the acrylic plate prepared by the method provided by the invention can meet the flame-retardant requirement, and simultaneously keeps the same excellent light transmittance. And other physical properties such as strength and heat resistance are improved to a certain extent, and the problem that the thermal property is reduced by using organic flame retardants such as phosphate is solved.

The halophosphate and dimethyl methylphosphonate were selected as flame retardants for organic glass because both compounds are colorless liquids and have good compatibility with MMA. And the refractive index is similar to that of PMMA, so that the transparency of the organic glass can be kept under the condition of achieving flame retardance.

Methacrylic acid with active hydrogen atoms can form hydrogen bonds with oxygen atoms on the carbonyl group of the substrate, so that the interaction force among polymer chains is enhanced. On the premise of not influencing the processing and shaping, the thermal deformation temperature of the organic glass is improved. And the methyl group of the methacrylic acid restricts the rotation of the main chain, and the glass transition temperature of the organic glass can be obviously improved. Therefore, the invention adopts methacrylic acid as a comonomer to improve the heat resistance of the flame-retardant organic glass.

The transparent flame-retardant heat-resistant organic glass plate prepared by the technical scheme has the characteristic of excellent flame-retardant property, and also has higher heat distortion temperature and transparency of not less than 90%, so that the application field and use value of the organic glass plate are widened.

In the vacuum defoaming process of pumping and stirring, firstly, bubble breaking can be accelerated, and the defoaming process can be accelerated; and the bubbles can drive fluid in the rising and breaking process, and the stirring action is realized, so that the stirring process can be accelerated.

It is noted that, in this document, relational terms such as first and second, and the like, if any, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.