阅读说明：本技术 聚氨酯胶片材料及其制备方法 (Polyurethane film material and preparation method thereof ) 是由 李旭 张运生 欧迎春 朱治国 蔡源春 于 2021-09-09 设计创作，主要内容包括：本发明是关于一种聚氨酯胶片材料及其制备方法,该制备方法包括：先以脂肪族二异氰酸酯35～50份、脂肪族单官能度异氰酸酯5～10份、分子量为500～3000的聚醚多元醇40～70份、小分子多元醇0～10份和第二催化剂0～0.3份为原料制备NCO封端聚氨酯预聚体,然后将NCO封端聚氨酯预聚体50～72份；端羟基混合物28～46份；抗氧化剂0.5～1.5份,光稳定剂1～1.5份,触变剂0.1～0.5份和第一催化剂0～0.5份混合,得到混合物,经流延反应成膜的方式制备聚氨酯胶片材料。该聚氨酯胶片材料包括分子量大于40万的高分子量聚氨酯和分子量为10～20万的低分子量聚氨酯。本发明制备的聚氨酯胶片材料为双分子量分布,没有晶点,具有热稳定性能好,光学性能优异等优点。(The invention relates to a polyurethane film material and a preparation method thereof, wherein the preparation method comprises the following steps: firstly, preparing an NCO-terminated polyurethane prepolymer by using 35-50 parts of aliphatic diisocyanate, 5-10 parts of aliphatic monofunctional isocyanate, 40-70 parts of polyether polyol with the molecular weight of 500-3000, 0-10 parts of micromolecular polyol and 0-0.3 part of second catalyst as raw materials, and then preparing 50-72 parts of the NCO-terminated polyurethane prepolymer; 28-46 parts of a hydroxyl-terminated mixture; 0.5-1.5 parts of antioxidant, 1-1.5 parts of light stabilizer, 0.1-0.5 part of thixotropic agent and 0-0.5 part of first catalyst are mixed to obtain a mixture, and the polyurethane sheet material is prepared by a casting reaction film forming mode. The polyurethane film material comprises high molecular weight polyurethane with the molecular weight of more than 40 ten thousand and low molecular weight polyurethane with the molecular weight of 10-20 ten thousand. The polyurethane film material prepared by the invention has bimolecular weight distribution, has no crystal point, and has the advantages of good thermal stability, excellent optical performance and the like.)

1. The preparation method of the polyurethane film material is characterized by comprising the following steps:

(1) preparing an NCO end-capped polyurethane prepolymer: firstly, mixing 35-50 parts by mass of aliphatic diisocyanate and 5-10 parts by mass of aliphatic monofunctional isocyanate, then adding 40-70 parts by mass of polyether polyol with the molecular weight of 500-3000, 0-10 parts by mass of micromolecular polyol and 0-0.3 part by mass of second catalyst in batches, controlling the R value of reactants to be 1.6-2.2, continuously stirring, preserving heat for 1-2 hours at 30-50 ℃ under the protection of nitrogen, and preserving heat for 1-2 hours at 60-70 ℃;

(2) preparing a polyurethane film material: mixing 50-72 parts by mass of NCO end-capped polyurethane prepolymer obtained in the step (1) with 28-46 parts by mass of a hydroxyl-terminated mixture, 0.5-1.5 parts by mass of an antioxidant, 1-1.5 parts by mass of a light stabilizer, 0.1-0.5 part by mass of a thixotropic agent and 0-0.5 part by mass of a first catalyst to obtain a mixture, casting the mixture into a film, heating and curing, rolling, and placing until the film is completely cured to obtain a polyurethane film material.

2. The preparation method of the polyurethane adhesive sheet material according to claim 1, wherein the molecular weight of the NCO-terminated polyurethane prepolymer is 1000-6000, the mass percentage of NCO is 4.7-8.3%, and the viscosity at 60 ℃ is less than 4000 mPa-s.

3. The method of preparing a polyurethane film material according to claim 1, wherein the aliphatic diisocyanate is at least one selected from the group consisting of hexamethylene diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, 4' -dicyclohexylmethane diisocyanate, cyclohexanedimethylene diisocyanate, cyclohexanediisocyanate, and hexahydrotoluenediisocyanate;

the aliphatic monofunctional isocyanate is selected from one of tert-butyl isocyanate, cyclohexyl isocyanate and hexyl isocyanate;

the polyether polyol is selected from at least one of polytetrahydrofuran glycol, polypropylene oxide glycol and polyethylene oxide glycol;

the micromolecular polyalcohol is at least one selected from 1, 4-butanediol, ethylene glycol, propylene glycol, methyl propylene glycol, diethylene glycol, 1, 4-cyclohexanol, neopentyl glycol, 1, 6-hexanediol and trimethylolpropane;

the second catalyst is at least one of organic tin, organic bismuth and organic zinc.

4. The method of preparing a polyurethane film material of claim 1, wherein said hydroxyl terminated mixture is prepared by the steps of:

mixing 58-73 parts of polyether polyol with the molecular weight of 500-4000 and 5-20 parts of micromolecular polyol by mass, adding 19-35 parts of polycarbonate polyol with the molecular weight of 500-3000, continuously stirring, keeping the temperature for 1-2h at 50-70 ℃ under the protection of nitrogen, and keeping the temperature for 1-2h at 70-90 ℃.

5. The method for preparing polyurethane film material according to claim 1 or 4, wherein the OH content of the hydroxyl-terminated mixture is 3-5% by mass, and the viscosity at 60 ℃ is less than 2000 mPa-s.

6. The method of preparing a polyurethane film material according to claim 4, wherein said polyether polyol is selected from at least one of polytetrahydrofuran glycol, polypropylene oxide glycol and polyethylene oxide glycol;

the micromolecular polyalcohol is at least one selected from 1, 4-butanediol, ethylene glycol, propylene glycol, methyl propylene glycol, diethylene glycol, 1, 4-cyclohexanol, neopentyl glycol, 1, 6-hexanediol and trimethylolpropane;

the molecular weight of the polycarbonate polyol is 500-3000, and the polycarbonate polyol is selected from at least one of UH-50, UH-100, UH-200, UH-300, PH-50, PH-100, PH-200, PH-300, BH-100, BH-200, UHC-50-200, UC, UM-90(3/1), UM-90(1/1), UM-90(1/3) and Desmophen @ C1200.

7. The method for preparing polyurethane film material according to claim 1, wherein the antioxidant is at least one selected from Irgastab PUR68, Irganox 245, BHT, antioxidant 1010, antioxidant 1035 and antioxidant 168;

the light stabilizer is selected from at least one of Tinuvin 101, UV327, UV328, UV320, UV-P, UV326, UV765, Tinuvin 770 and Chimassorb 944;

the thixotropic agent is at least one selected from BYK-410, BYK-411, BYK420 and Borchi Gel L75N;

the first catalyst is at least one of organic tin, organic bismuth, organic zinc or tertiary amine.

8. The polyurethane film material is characterized by comprising high molecular weight polyurethane and low molecular weight polyurethane, wherein the molecular weight of the high molecular weight polyurethane is more than 40 ten thousand, and the molecular weight of the low molecular weight polyurethane is 10-20 ten thousand.

9. Polyurethane film material according to claim 8,

the mass ratio of the high molecular weight polyurethane to the low molecular weight polyurethane is 0.8-1.6.

10. Polyurethane film material according to claim 8,

the high molecular weight polyurethane forms a film skeleton, and the low molecular weight polyurethane is inserted between the skeletons formed by the high molecular weight polyurethane.

Technical Field

The invention relates to the technical field of optical polyurethane elastomers, in particular to a polyurethane film material and a preparation method thereof.

Background

The safety glass with composite structure is generally referred to as laminated glass, and the laminated glass is formed by sandwiching and bonding tough films between two or more layers of glass. When the laminated glass is impacted by external force to cause the glass to break, fragments of the glass can still be adhered to the film to form radial cracks only, and the human casualty accident caused by the scattering of the fragments cannot be caused, so that the glass has good safety performance. In addition, the glass also has the characteristics of sound insulation, ultraviolet ray insulation and the like, so that the glass is suitable for being applied to the outer protective structure of modern buildings and the interior of the buildings, including civil buildings and household bathrooms.

Currently, the interlayer adhesive sheet for laminated glass is mainly composed of polyvinyl butyral (PVB), Thermoplastic Polyurethane (TPU), ethylene-vinyl acetate copolymer (EVA), and the like. Among them, PVB is widely used in the fields of building glass, curtain wall glass, automobile glass, etc., but when the low temperature is low (below zero), the material is brittle, the bonding strength between the material and organic glass and inorganic glass is greatly weakened, even if plasticizer is added into PVB to improve the low temperature brittleness, the adding effect is not ideal, and the mechanical property is sharply reduced, and meanwhile, the plasticizer can erode the surface of PC, causing the glass to fog.

The polyurethane film for laminated glass is mostly formed by melting, extruding and casting TPU particles, so that the film is limited by production processes and raw materials, the molecular weight is low, the molecular weight of polyether TPU is about 9 ten thousand, and the molecular weight of polyester TPU is about 12 ten thousand, so that the material has poor thermal stability, and is easy to melt and soften and lose structural bonding strength at high temperature. In addition, because the molecular weight distribution of the TPU particles is not uniform, the melting state of the TPU particles is inconsistent at the casting extrusion molding temperature, the melting temperature of the high molecular weight TPU is higher, and the TPU particles are in an incompletely molten state, and the incompletely molten TPU particles form crystal points after casting molding, so that the TPU particles cannot be directly applied to laminated glass.

Disclosure of Invention

The invention mainly aims to provide a polyurethane film material and a preparation method thereof, and aims to solve the technical problem of improving the thermal stability and the optical performance of the polyurethane film material.

The object of the present invention and the technical problem to be solved are achieved by the following technical means. According to the preparation method of the polyurethane film material provided by the invention, the preparation method comprises the following steps:

(1) preparing an NCO end-capped polyurethane prepolymer: firstly, mixing 35-50 parts by mass of aliphatic diisocyanate and 5-10 parts by mass of aliphatic monofunctional isocyanate, then adding 40-70 parts by mass of polyether polyol with the molecular weight of 500-3000, 0-10 parts by mass of micromolecular polyol and 0-0.3 part by mass of second catalyst in batches, controlling the R value of reactants to be 1.6-2.2, continuously stirring, preserving heat for 1-2 hours at 30-50 ℃ under the protection of nitrogen, and preserving heat for 1-2 hours at 60-70 ℃;

(2) preparing a polyurethane film material: mixing 50-72 parts by mass of NCO end-capped polyurethane prepolymer obtained in the step (1) with 28-46 parts by mass of a hydroxyl-terminated mixture, 0.5-1.5 parts by mass of an antioxidant, 1-1.5 parts by mass of a light stabilizer, 0.1-0.5 part by mass of a thixotropic agent and 0-0.5 part by mass of a first catalyst to obtain a mixture, casting the mixture into a film, heating and curing, rolling, and placing until the film is completely cured to obtain a polyurethane film material.

The object of the present invention and the technical problems solved thereby can be further achieved by the following technical measures.

Preferably, in the preparation method of the polyurethane adhesive sheet material, the molecular weight of the NCO-terminated polyurethane prepolymer is 1000-6000, the mass percentage content of NCO is 4.7-8.3%, and the viscosity at 60 ℃ is less than 4000mPa · s.

Preferably, in the preparation method of the polyurethane film material, the aliphatic diisocyanate is at least one selected from the group consisting of hexamethylene diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, 4' -dicyclohexylmethane diisocyanate, cyclohexanedimethylene diisocyanate, cyclohexanediisocyanate and hexahydrotoluenediisocyanate;

the aliphatic monofunctional isocyanate is selected from one of tert-butyl isocyanate, cyclohexyl isocyanate and hexyl isocyanate;

the polyether polyol is selected from at least one of polytetrahydrofuran glycol, polypropylene oxide glycol and polyethylene oxide glycol;

the micromolecular polyalcohol is at least one selected from 1, 4-butanediol, ethylene glycol, propylene glycol, methyl propylene glycol, diethylene glycol, 1, 4-cyclohexanol, neopentyl glycol, 1, 6-hexanediol and trimethylolpropane;

the second catalyst is at least one of organic tin, organic bismuth and organic zinc.

Preferably, the preparation method of the polyurethane film material, wherein the preparation method of the hydroxyl-terminated mixture comprises the following steps:

mixing 58-73 parts of polyether polyol with the molecular weight of 500-4000 and 5-20 parts of micromolecular polyol by mass, adding 19-35 parts of polycarbonate polyol with the molecular weight of 500-3000, continuously stirring, keeping the temperature for 1-2h at 50-70 ℃ under the protection of nitrogen, and keeping the temperature for 1-2h at 70-90 ℃.

Preferably, in the preparation method of the polyurethane film material, the OH mass percentage of the hydroxyl-terminated mixture is 3-5%, and the viscosity at 60 ℃ is less than 2000mPa · s.

Preferably, in the preparation method of the polyurethane sheet material, the polyether polyol is at least one selected from polytetrahydrofuran glycol, polypropylene oxide glycol and polyethylene oxide glycol;

the micromolecular polyalcohol is at least one selected from 1, 4-butanediol, ethylene glycol, propylene glycol, methyl propylene glycol, diethylene glycol, 1, 4-cyclohexanol, neopentyl glycol, 1, 6-hexanediol and trimethylolpropane;

the molecular weight of the polycarbonate polyol is 500-3000, and the polycarbonate polyol is selected from at least one of UH-50, UH-100, UH-200, UH-300, PH-50, PH-100, PH-200, PH-300, BH-100, BH-200, UHC-50-200, UC, UM-90(3/1), UM-90(1/1), UM-90(1/3) and Desmophen @ C1200.

Preferably, the preparation method of the polyurethane sheet material is that the antioxidant is at least one selected from Irgastab PUR68, Irganox 245, BHT, antioxidant 1010, antioxidant 1035 and antioxidant 168;

the light stabilizer is selected from at least one of Tinuvin 101, UV327, UV328, UV320, UV-P, UV326, UV765, Tinuvin 770 and Chimassorb 944;

the thixotropic agent is at least one selected from BYK-410, BYK-411, BYK420 and Borchi Gel L75N;

the first catalyst is at least one of organic tin, organic bismuth, organic zinc or tertiary amine.

The purpose of the invention and the technical problem to be solved are realized by adopting the following technical scheme. The polyurethane film material provided by the invention comprises high molecular weight polyurethane and low molecular weight polyurethane, wherein the molecular weight of the high molecular weight polyurethane is more than 40 ten thousand, and the molecular weight of the low molecular weight polyurethane is 10-20 ten thousand.

The object of the present invention and the technical problems solved thereby can be further achieved by the following technical measures.

Preferably, in the polyurethane film material, the mass ratio of the high molecular weight polyurethane to the low molecular weight polyurethane is 0.8 to 1.6.

Preferably, in the polyurethane sheet material, the high molecular weight polyurethane forms a film skeleton, and the low molecular weight polyurethane is inserted between the skeletons formed by the high molecular weight polyurethane.

By the technical scheme, the polyurethane film material and the preparation method thereof provided by the invention at least have the following advantages:

1. the main raw materials of the polyurethane sheet material are NCO-terminated polyurethane prepolymer and a hydroxyl-terminated mixture, the NCO-terminated polyurethane prepolymer is mainly prepared from aliphatic diisocyanate and aliphatic monofunctional isocyanate, and the monofunctional isocyanate reacts to digest hydroxyl groups, so that partial chain segment reaction is stopped, the size of partial molecular weight can be controlled, different molecular weight mixing states are formed, the polyurethane sheet containing high molecular weight polyurethane and low molecular weight polyurethane is prepared, and the proportion of the high molecular weight polyurethane to the low molecular weight polyurethane can be adjusted by adjusting the proportion of the aliphatic diisocyanate to the aliphatic monofunctional isocyanate. The polyurethane film material prepared by the method has bimolecular distribution, has no crystal points, and has the advantages of good thermal stability, excellent optical performance and the like.

2. The two-component polyurethane is in a solution state, the two-component polyurethane is mixed to directly form a film by tape casting, molecules are gradually reacted and cured in the process of film forming by tape casting, and the molecular weight is gradually increased, so that the molecular weight does not influence the process of the film preparation process, and the reaction process of the film is still slowly carried out after the film is subjected to surface dry shaping and rolling, so that the high molecular weight is achieved, and the temperature-resistant optical-grade polyurethane film material with good thermal stability and excellent optical performance is obtained. The invention combines the preparation of polyurethane raw materials and the preparation of rubber sheets, is not limited by the preparation and melting of intermediate colloidal particles, and has no melting process in the whole process, namely, the problem of incomplete melting crystal points.

3. The polyurethane film material comprises high molecular weight polyurethane and low molecular weight polyurethane, wherein the molecular weight of the high molecular weight polyurethane is more than 40 ten thousand, and the molecular weight of the low molecular weight polyurethane is 10-20 ten thousand. The high molecular weight polyurethane can ensure the high temperature performance of the polyurethane film material, the polyurethane film material is kept stable in a high temperature state, the melting phenomenon cannot occur, and the low molecular weight polyurethane is softened and sticky at the glass laminating temperature, so that the good bonding of the film and the glass is realized. The high molecular weight polyurethane forms a high-temperature stable film skeleton, and the low molecular weight polyurethane is inserted between the skeletons formed by the high molecular weight polyurethane, so that the bonding performance is ensured. Meanwhile, the polyurethane film material has excellent thermal stability and optical performance, and the transparent polyurethane film material can meet the application and use requirements of the aviation laminated glass.

4. The polyurethane film material is a novel interlayer bonding material, overcomes the defects of a PVB film, and can bond inorganic glass, Polycarbonate (PC) plates, PET plates and other transparent organic materials from low temperature to high temperature. The polyurethane sheet material of the invention provides the possibility of inorganic and organic compounding, and provides a product with light weight and high strength for the market. Can be widely applied to the building industry, the automobile industry, the aviation industry and the financial industry, and is particularly suitable for bullet-proof glass.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

FIG. 1 shows a flow diagram for the preparation of a polyurethane film material according to an embodiment of the present invention;

FIG. 2 shows a relative chromatogram of the molecular weight distribution of a polyurethane film material of example 1 of the present invention;

FIG. 3 shows a relative chromatogram of the molecular weight distribution of a polyurethane film material of example 2 of the present invention;

FIG. 4 shows a relative chromatogram of the molecular weight distribution of a polyurethane film material of example 3 of the present invention;

fig. 5 shows a relative chromatogram of the molecular weight distribution of the polyurethane film material of comparative example 1 of the present invention.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description of the embodiments, structures, characteristics and effects of the polyurethane sheet material and the preparation method thereof according to the present invention will be made with reference to the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

As shown in fig. 1, one embodiment of the present invention provides a method for preparing a polyurethane film material, where the method for preparing a polyurethane film material by a casting reaction film formation method specifically includes the following steps:

(1) preparing an NCO end-capped polyurethane prepolymer: adding 35-50 parts by mass of aliphatic diisocyanate and 5-10 parts by mass of aliphatic monofunctional isocyanate into a reaction kettle, and adding 40-70 parts by mass of polyether polyol with the molecular weight of 500-3000, 0-10 parts by mass of micromolecular polyol and 0-0.3 part by mass of second catalyst in batches; controlling the R value of the reactant to be 1.6-2.2; continuously stirring, gradually heating under the protection of nitrogen, preserving heat for 1-2h at 30-50 ℃, preserving heat for 1-2h at 60-70 ℃, stopping heating after the reaction is completed (the mass percentage of NCO reaches 4.7-8.3%), naturally cooling, and sealing and storing;

in the present embodiment, the R value is a ratio of the sum of the number of moles of NCO groups contained in the aliphatic diisocyanate and the aliphatic monofunctional isocyanate to the sum of the number of moles of OH groups contained in the polyether polyol and the small molecule polyol. According to the technical scheme of the embodiment, the R value of the reaction raw material is controlled to be 1.6-2.2, so that the end group of the prepared polyurethane prepolymer is controlled to be NCO end-capped.

Furthermore, the molecular weight of the NCO-terminated polyurethane prepolymer is 1000-6000, the mass percentage of NCO is 4.7-8.3%, and the viscosity at 60 ℃ is less than 4000mPa & s.

In this step, the aliphatic diisocyanate is selected from at least one of hexamethylene diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate, 4' -dicyclohexylmethane diisocyanate, cyclohexanedimethylene diisocyanate, cyclohexanediisocyanate and hexahydrotoluene diisocyanate;

the aliphatic monofunctional isocyanate is selected from one of tert-butyl isocyanate, cyclohexyl isocyanate and hexyl isocyanate;

the polyether polyol is selected from at least one of polytetrahydrofuran glycol, polypropylene oxide glycol and polyethylene oxide glycol;

the micromolecular polyalcohol is at least one selected from 1, 4-butanediol, ethylene glycol, propylene glycol, methyl propylene glycol, diethylene glycol, 1, 4-cyclohexanol, neopentyl glycol, 1, 6-hexanediol and trimethylolpropane;

the second catalyst is at least one of organic tin, organic bismuth and organic zinc.

(2) Preparation of hydroxyl-terminated mixture: adding 58-73 parts by mass of polyether polyol with the molecular weight of 500-4000 and 5-20 parts by mass of micromolecular polyol into a reaction kettle, adding 19-35 parts by mass of polycarbonate polyol with the molecular weight of 500-3000, continuously stirring, gradually heating under the protection of nitrogen, keeping the temperature at 50-70 ℃ for 1-2h, keeping the temperature at 80-90 ℃ for 1-2h, stopping heating after the reaction is completed, naturally cooling, and sealing for storage;

furthermore, the OH content of the hydroxyl-terminated mixture is 3-5% by mass, and the viscosity at 60 ℃ is less than 2000mPa & s.

In this step, the polyether polyol is selected from at least one of polytetrahydrofuran glycol, polypropylene oxide glycol and polyethylene oxide glycol;

the micromolecular polyalcohol is at least one selected from 1, 4-butanediol, ethylene glycol, propylene glycol, methyl propylene glycol, diethylene glycol, 1, 4-cyclohexanol, neopentyl glycol, 1, 6-hexanediol and trimethylolpropane;

the molecular weight of the polycarbonate polyol is 500-3000, and the polycarbonate polyol is selected from at least one of UH-50, UH-100, UH-200, UH-300, PH-50, PH-100, PH-200, PH-300, BH-100, BH-200, UHC-50-200, UC, UM-90(3/1), UM-90(1/1), UM-90(1/3) and Desmophen @ C1200.

(3) Preparing a polyurethane film material by a casting reaction film forming method: 50-72 parts by mass of NCO-terminated polyurethane prepolymer; 28-46 parts of a hydroxyl-terminated mixture; 0.5-1.5 parts of antioxidant, 1-1.5 parts of light stabilizer, 0.1-0.5 part of thixotropic agent and 0-0.5 part of first catalyst are mixed, added into a casting machine, cast on a plane conveying film through a die head, cast into a film, adopt a roller to roll to set the thickness and the width, adopt an infrared or microwave mode to heat and solidify for 2-5 min in the conveying process of the conveying film, control the reaction rate, discharge liquid from the casting machine to surface dry, the solidifying time is less than 5min, ensure that the material solidifying degree reaches the film shape, roll up after the material shape is stable, place for 14d, the film is completely solidified, test the performance, and the molecular weight of the polyurethane elastomer material after complete solidification is more than 40 ten thousand high molecular weight and about 10-20 ten thousand low molecular weight mixed state.

In this step, the antioxidant is at least one selected from Irgastab PUR68, Irganox 245, BHT, antioxidant 1010, antioxidant 1035 and antioxidant 168;

the light stabilizer is selected from at least one of Tinuvin 101, UV327, UV328, UV320, UV-P, UV326, UV765, Tinuvin 770 and Chimassorb 944;

the thixotropic agent is at least one selected from BYK-410, BYK-411, BYK420 and Borchi Gel L75N;

the first catalyst is at least one of organic tin, organic bismuth, organic zinc or tertiary amine.

In the present invention, unless otherwise specified, the molecular weight means a weight average molecular weight. For example, polyether polyol with the molecular weight of 500-4000, the molecular weight of high molecular weight polyurethane is more than 40 ten thousand, and the molecular weight of low molecular weight polyurethane is 10-20 ten thousand, and the like, which refer to the weight average molecular weight.

The reaction mechanism is as follows: the monofunctional isocyanate reacts to digest hydroxyl groups, so that partial chain segments are stopped to control the molecular weight of part of the chain segments, and a mixed state of different molecular weights is formed.

When difunctional isocyanates and difunctional alcohols are used in equal proportions, it is theoretically possible to form molecules of very high molecular weight, the reaction formula is as follows:

when monofunctional isocyanate is present, the reaction of monofunctional isocyanate with hydroxyl group will result in the termination of segment reaction and the formation of molecules with smaller molecular weight, and the reaction formula is as follows:

the invention controls the molecular weight and molecular weight distribution formed by material reaction by controlling the proportion of bifunctional isocyanate and monofunctional isocyanate and the preparation process.

The process of synthesizing macromolecules by small molecule reaction is in the same reaction kettle, and the molecules with different molecular weights are generated in the same synthesis process, so the molecules with different molecular weights are in a uniform dispersion state in the material, and the phenomenon of similar crystal point aggregation can not occur.

In this embodiment, the molecular weight distribution of the polyurethane film material is controlled by controlling the feeding proportion, the feeding sequence, the reaction time and the reaction degree.

The polyurethane sheet material is a temperature-resistant optical polyurethane sheet, the main raw materials of the temperature-resistant optical polyurethane sheet material are NCO-terminated polyurethane prepolymer and a hydroxyl-terminated mixture, the NCO-terminated polyurethane prepolymer is prepared from aliphatic diisocyanate and aliphatic monofunctional isocyanate, and the monofunctional isocyanate reacts to digest hydroxyl groups, so that partial chain segment reaction is terminated, the size of partial molecular weight can be controlled, different molecular weight mixed states are formed, and the polyurethane sheet containing high molecular weight polyurethane and low molecular weight polyurethane is prepared.

In the present embodiment, the mass ratio of the high molecular weight polyurethane and the low molecular weight polyurethane can be adjusted by adjusting the ratio of the aliphatic diisocyanate and the aliphatic monofunctional isocyanate in the raw materials. Preferably, the mass ratio of the high molecular weight polyurethane to the low molecular weight polyurethane is 0.8-1.6.

The polyurethane film material prepared by adopting the two-component polyurethane raw material forms a special molecular weight distribution state after being completely cured, and simultaneously has a state of combination of high molecular weight and low molecular weight, wherein the molecular weight of the high molecular weight polyurethane is more than 40 ten thousand, and the molecular weight of the low molecular weight polyurethane is about 10-20 ten thousand, wherein the high molecular weight polyurethane can ensure the high-temperature performance of the polyurethane film material, and the high-temperature polyurethane is stable in a high-temperature state, so that the melting phenomenon cannot occur, and the low molecular weight polyurethane softens and sticks at the glass laminating temperature, thereby realizing good bonding of the film and the glass. The high molecular weight polyurethane forms a high-temperature stable film skeleton, and the low molecular weight polyurethane is inserted between the skeletons formed by the high molecular weight polyurethane, so that the bonding performance is ensured. Although there is a distribution of molecules having different molecular weights, molecules having a large molecular weight are reacted with molecules having a small molecular weight, and therefore, the degree of dispersion between the molecules is on a molecular scale, and there is no problem that the molecules are not uniformly dispersed, and thus, crystal spots are not generated. Therefore, the polyurethane film material prepared by adopting the casting reaction curing mode has excellent thermal stability and optical performance, does not have the problems of crystal points and the like, and can meet the application and use requirements of the aviation laminated glass.

Compared with the existing preparation method of the polyurethane film, the preparation method of the invention is obviously different. In the existing preparation method of the polyurethane film, a thermoplastic polyurethane material is adopted for granulation, and then the granulation is carried out by melting and tape casting to form the film, because the preparation of the polyurethane raw material is separated from the preparation of the polyurethane film, the prepared colloidal particles have limitation, the molecular weight of the colloidal particle material needs to be controlled in order to ensure that the colloidal particles can be melted when the film is prepared, the colloidal particles can only be used as a linear thermoplastic polyurethane material, the polyether molecular weight is about 9 ten thousand, and the polyester molecular weight is about 12 ten thousand. Because the film is in a thermoplastic state, the laminated glass can form viscous flow due to the thermoplastic characteristic after being heated, so that the bonding of the laminated glass fails, and on the other hand, the molecular weight distribution of the materials in the prepared polyurethane adhesive particles has certain dispersion, the outflow temperature adopted by melt flow is a fixed temperature, the polyurethane materials with different molecular weights are different in melt state, and the melt with larger molecular weight is incomplete, so that the crystal points of the formed film exist, and the optical performance is affected. The invention adopts two-component polyurethane material, prepares film through reaction casting solidification, combines the polyurethane raw material preparation and film production preparation together, is not limited by intermediate colloidal particle preparation and fusion, thereby can prepare high molecular weight polyurethane, polyurethane adopts two-component reaction solidification, gradually reacts and solidifies in the casting film forming process, the molecular weight is gradually increased, the thickness is fixed through rolling, heating solidification is realized, surface drying is realized in the heating process, the appearance of the film is fixed after surface drying, the film can be rolled and placed, and placed at room temperature, the post-solidification process is carried out, and the film performance reaches the best after being placed for 14 d. The whole process has no melting process, the problem of incomplete melting crystal points does not exist, the double-component polyurethane is in a solution state, casting film forming can be realized, molecules are gradually reacted and solidified in the casting film forming process, the molecular weight is gradually increased, so the molecular weight cannot influence the film preparation process, and after the film surface is dried, shaped and rolled, the film reaction process is still carried out slowly, and then high molecular weight is achieved. Therefore, the embodiment of the invention solves the problem that the production and preparation of the existing polyurethane film are limited by raw materials and production processes, prepares the polyurethane film with excellent optical performance and excellent thermal stability, and meets the application and use requirements of the aviation laminated glass.

Compared with the traditional polyurethane film, the polyurethane film prepared by the invention has obvious thermal stability, and breaks through the limitation of the traditional preparation process on the material performance.

Another embodiment of the present invention provides a polyurethane film material, which includes high molecular weight polyurethane and low molecular weight polyurethane, wherein the molecular weight of the high molecular weight polyurethane is greater than 40 ten thousand, and the molecular weight of the low molecular weight polyurethane is 10 to 20 ten thousand.

The polyurethane film material comprises high molecular weight polyurethane and low molecular weight polyurethane, wherein the molecular weight of the high molecular weight polyurethane is more than 40 ten thousand, and the molecular weight of the low molecular weight polyurethane is 10-20 ten thousand. The high molecular weight polyurethane can ensure the high temperature performance of the polyurethane film material, the polyurethane film material is kept stable in a high temperature state, the melting phenomenon cannot occur, and the low molecular weight polyurethane is softened and sticky at the glass laminating temperature, so that the good bonding of the film and the glass is realized. The high molecular weight polyurethane forms a high-temperature stable film skeleton, and the low molecular weight polyurethane is inserted between the skeletons formed by the high molecular weight polyurethane, so that the bonding performance is ensured. Meanwhile, the polyurethane film material has excellent thermal stability and optical performance, and the transparent polyurethane film material can meet the application and use requirements of the aviation laminated glass.

It is obvious from Gel Permeation Chromatography (GPC) detection that the polyurethane film material of the present embodiment is in a state of high-low molecular weight complex, and the high-molecular weight and low-molecular weight polyurethane molecules in the polyurethane material are uniformly dispersed. From mechanism, high molecular weight and low molecular weight are obtained by gradually adding and polymerizing small molecules in the same reaction solution, and are subjected to common reaction in the same system, high molecular weight and low molecular weight are naturally formed along with the reaction, and the reaction conditions and the reaction process of the two molecular weight molecules are completely consistent, so that the high molecular weight and the low molecular weight molecules are completely uniformly and randomly distributed in the system, and the aggregation phenomenon does not exist. From the chemical property, the high molecular weight molecules and the low molecular weight molecules have the same polarity of functional groups, chain links and chemical bonds, and the problem of phase separation does not exist in the synthetic process. From the aspect of optical performance, the whole material has uniform optical performance, does not have optical distortion or anisotropy, and belongs to an isotropic amorphous elastomer.

The molecular weight distribution of the material is tested by gel permeation chromatography, the strength of a peak represents the concentration of the material in the solution according to the calculation of a molecular weight distribution curve, and the concentrations of different molecular weights in the solution can be obtained by comparing the strengths of the peaks of different molecular weights in the molecular weight distribution curve, so that the mass ratio of the high molecular weight polyurethane to the low molecular weight polyurethane is obtained.

In some embodiments, the mass ratio of the high molecular weight polyurethane to the low molecular weight polyurethane is 0.8 to 1.6, e.g., 1.0, 1.2, 1.4, 1.5.

The method ensures that the obtained polyurethane film material has better optical performance by adjusting the proportion of the high molecular weight polyurethane and the low molecular weight polyurethane, because the regulation and control of the molecular weight can be regulated and controlled by the proportion of the synthetic raw materials, and the proportion relation between the high molecular weight and the low molecular weight can be calculated from the peak intensity proportion of different molecular weights in a molecular weight distribution curve. The invention combines the preparation of polyurethane raw materials and the preparation of rubber sheets, is not limited by the preparation and melting of intermediate colloidal particles, and has no melting process in the whole process, namely, the problem of incomplete melting crystal points.

By adopting the mode of matching high molecular weight and low molecular weight, the molecular melting temperature of the high molecular weight is higher, so that the mechanical property of the whole film can be kept at high temperature, and the influence of the high temperature on the film strength is weakened. The molecules with lower molecular weight are converted to viscous state when heated, and can form good bonding effect with bonding interface. The combination of high and low molecular weight makes the film have good thermal stability and good adhesive property. The film with the molecular weight distribution prepared by the preparation process is provided. In the traditional preparation method, the mode of preparing colloidal particles and then preparing a film by secondary melting is adopted, in order to ensure the melting and casting of the colloidal particles, the molecular weight is generally about one hundred thousand, the low molecular weight causes the poor temperature resistance of the film, the poor strength of the film at high temperature, when high molecular weight molecules exist in the colloidal particles, the melting degree is different at the same temperature, the high molecular weight molecules are not completely melted in the molten liquid, crystal points are formed in the cast film, and the optical performance of the film is influenced. Embodiments of the present invention address this problem by selection of raw materials and control of the preparation process.

The present invention will be further described with reference to the following specific examples, which should not be construed as limiting the scope of the invention, but rather as providing those skilled in the art with certain insubstantial modifications and adaptations of the invention based on the teachings of the invention set forth herein.

In the following examples of the present invention, unless otherwise specified, all the components referred to are commercially available products well known to those skilled in the art, and if not specified, all the methods referred to are conventional methods.

Example 1

A preparation method of a polyurethane film material comprises the following specific steps:

(1) preparing an NCO end-capped polyurethane prepolymer: adding 35 parts by mass of 4, 4' -dicyclohexylmethane diisocyanate and 5 parts by mass of tert-butyl isocyanate into a reaction kettle, adding 57 parts by mass of polytetrahydrofuran glycol and 3 parts by mass of a 1:1 mixture of ethylene glycol and diethylene glycol in batches, and controlling the R value of reactants to be 2; continuously stirring, gradually heating under the protection of nitrogen, keeping the temperature at 40 ℃ for 2h, keeping the temperature at 60 ℃ for 2h, stopping heating when the NCO content reaches a theoretical value of 4.3%, naturally cooling, and sealing for storage;

(2) preparation of hydroxyl-terminated mixture: adding 60 parts of polytetrahydrofuran glycol and 10 parts of 1, 4-butanediol by mass into a reaction kettle, adding UH-20013 parts, PH-20010 parts and BH-2007 parts, continuously stirring, heating gradually under the protection of nitrogen, keeping the temperature at 60 ℃ for 2 hours, keeping the temperature at 80 ℃, stopping heating after uniform mixing, naturally cooling, and sealing for storage;

(3) casting into a film: 53 parts of NCO-terminated polyurethane prepolymer, 44 parts of hydroxyl-terminated mixture, 10101 parts of antioxidant, UV-3281.3 parts of light stabilizer, BYK 4100.4 parts of thixotropic agent and 0.3 part of zinc neodecanoate catalyst are mixed in a casting machine by mass, the mixture is cast on a transmission substrate through a die head, the transmission substrate is conveyed through a heating device channel for heating and curing, the thickness is set by rolling, the curing is carried out for 3-5 min, the mixture is rolled and placed for 14d after the setting degree is reached, the polyurethane sheet material is obtained, and the performance of the polyurethane sheet material is tested.

According to the detection of GB/T528-2009 determination of tensile stress strain performance of vulcanized rubber or thermoplastic rubber, the tensile strength of the polyurethane rubber sheet material obtained in the embodiment at room temperature is 50MPa, the elongation at break is 680%, the tear strength is 63kN/m, the transmittance is 91%, and the haze is 0.5%.

The molecular weight distribution of the polyurethane film material obtained in this example, as measured by Gel Permeation Chromatography (GPC), is shown in FIG. 2, and the molecular weight distribution data is shown in Table 1. It is calculated that the mass ratio of the high molecular weight polyurethane to the low molecular weight polyurethane in the polyurethane film material of this example is 1.38.

Table 1 molecular weight distribution of polyurethane film material obtained in example 1

Example 2

A preparation method of a polyurethane film material comprises the following specific steps:

(1) preparing an NCO end-capped polyurethane prepolymer: adding 40 parts by mass of isophorone diisocyanate and 5 parts by mass of cyclohexyl isocyanate into a reaction kettle, adding 52 parts by mass of polytetrahydrofuran diol and 3 parts by mass of a mixture of 1, 4-butanediol and trimethylolpropane in batches, and controlling the R value of reactants to be 2; continuously stirring, gradually heating under the protection of nitrogen, keeping the temperature at 40 ℃ for 2h, keeping the temperature at 80 ℃ for 2h, stopping heating when the NCO content reaches 4.4% of a theoretical value, naturally cooling, and sealing for storage;

(2) preparation of hydroxyl-terminated mixture: adding 57 parts by mass of polytetrahydrofuran glycol, 20 parts by mass of 1, 4-butanediol, BH-20010 parts by mass of UHC-50-20013 parts by mass into a reaction kettle, continuously stirring, heating gradually under the protection of nitrogen, keeping the temperature at 60 ℃ for 2 hours, keeping the temperature at 80 ℃, stopping heating after uniform mixing, naturally cooling, and sealing for storage;

(3) casting into a film: 56 parts of NCO-terminated polyurethane prepolymer, 41 parts of hydroxyl-terminated mixture, Irgastab PUR 681 parts, UV 3280.5 parts of light stabilizer, UV 3200.6 parts, BYK 4200.5 parts of thixotropic agent and 0.4 part of organic tin catalyst are mixed in a casting machine, the mixture is cast on a conveying substrate through a die head, the conveying substrate is conveyed through a heating device channel for heating and curing, the thickness is determined by rolling and curing for 3-5 min, after the setting degree is reached, the mixture is rolled and placed for 14d, a polyurethane sheet material is obtained, and the performance of the polyurethane sheet material is tested.

According to the detection of GB/T528-2009 determination of tensile stress strain performance of vulcanized rubber or thermoplastic rubber, the tensile strength of the polyurethane rubber sheet material obtained in the embodiment at room temperature is 41MPa, the elongation at break is 780%, the tear strength is 52kN/m, the transmittance is 91%, and the haze is 0.4%.

The polyurethane film material (elastomer after curing) obtained in this example was swollen in tetrahydrofuran, was insoluble, and was in a crosslinked macromolecular state, and the molecular weight of the dissolved portion was measured, and the molecular weight distribution measured by Gel Permeation Chromatography (GPC) was as shown in fig. 3, and the molecular weight distribution data thereof is shown in table 2. It is calculated that the mass ratio of the high molecular weight polyurethane to the low molecular weight polyurethane in the polyurethane film material of this example is 0.83.

Table 2 molecular weight distribution of polyurethane film material obtained in example 2

Example 3

A preparation method of a polyurethane film material comprises the following specific steps:

(1) preparing an NCO end-capped polyurethane prepolymer: adding 37 parts by mass of isophorone diisocyanate and 5 parts by mass of hexyl isocyanate into a reaction kettle, adding 55 parts by mass of polytetrahydrofuran diol and 3 parts by mass of a mixture of 1, 4-butanediol and trimethylolpropane in batches, and controlling the R value of reactants to be 2; continuously stirring, gradually heating under the protection of nitrogen, keeping the temperature at 40 ℃ for 2h, keeping the temperature at 80 ℃ for 2h, stopping heating when the NCO content reaches 4.4% of a theoretical value, naturally cooling, and sealing for storage;

(2) preparation of hydroxyl-terminated mixture: adding 65 parts of polyethylene oxide glycol, 17 parts of 1, 4-butanediol, 5 parts of UM-90(1/1), 5 parts of UM-90(1/3) and 120013 parts of Desmophen @ C into a reaction kettle, continuously stirring, gradually heating under the protection of nitrogen, keeping the temperature at 60 ℃ for 2 hours, keeping the temperature at 80 ℃, stopping heating after uniform mixing, naturally cooling, and sealing for storage;

(3) casting into a film: according to parts by mass, 70 parts of NCO-terminated polyurethane prepolymer, 27 parts of hydroxyl-terminated mixture, 10350.5 parts of antioxidant, 1680.5 parts of antioxidant, 0.5 part of antioxidant BHT, 1010.5 parts of light stabilizer Tinuvin, UV 7650.5 parts, BYK-4110.2 parts of thixotropic agent and 0.3 part of organic bismuth catalyst are mixed in a casting machine, the mixture is cast on a conveying substrate through a die head, the conveying substrate is conveyed through a heating device channel for heating and curing, the roller is rolled for thickness setting, the curing is carried out for 3-5 min, the curing is carried out for 14d after the setting degree is reached, and a polyurethane sheet material is obtained and the performance of the polyurethane sheet material is tested.

According to the detection of GB/T528-2009 determination of tensile stress strain performance of vulcanized rubber or thermoplastic rubber, the tensile strength of the polyurethane rubber sheet material obtained in the embodiment at room temperature is 36.5MPa, the elongation at break is 720%, the tear strength is 46kN/m, the transmittance is 91%, and the haze is 0.5%.

The molecular weight distribution of the polyurethane film material obtained in this example, as measured by Gel Permeation Chromatography (GPC), is shown in FIG. 4, and the molecular weight distribution data is shown in Table 3. It is calculated that the mass ratio of the high molecular weight polyurethane to the low molecular weight polyurethane in the polyurethane film material of this example is 1.11.

Table 3 molecular weight distribution of polyurethane film material obtained in example 3

Comparative example 1

A PE399 polyurethane film manufactured by Hensmei company was selected.

The polyurethane film of comparative example 1 had a tensile strength of 44.5MPa at room temperature, an elongation at break of 530%, a tear strength of 36.75kN/m, a transmittance of 91%, and a haze of 0.5%.

The molecular weight distribution of the polyurethane film of comparative example 1 is shown in FIG. 5, and the molecular weight distribution data is shown in Table 4.

Table 4 molecular weight distribution of the polyurethane film of comparative example 1

Comparative example 2

Comparative example 2 no monofunctional isocyanate was added.

(1) Preparing an NCO end-capped polyurethane prepolymer: adding 38 parts by mass of 4, 4' -dicyclohexylmethane diisocyanate into a reaction kettle, adding 57 parts by mass of polytetrahydrofuran glycol and 3 parts by mass of a mixture of ethylene glycol and diethylene glycol, and controlling the R value of a reactant to be 2; continuously stirring, gradually heating under the protection of nitrogen, keeping the temperature at 40 ℃ for 2h, keeping the temperature at 60 ℃ for 2h, stopping heating when the NCO content reaches a theoretical value of 4.27%, naturally cooling, and sealing for storage;

(2) preparation of hydroxyl-terminated mixture: adding 60 parts of polytetrahydrofuran glycol and 15 parts of 1, 4-butanediol by mass into a reaction kettle, adding UH-5010 parts and PH-30015 parts, continuously stirring, gradually heating under the protection of nitrogen, keeping the temperature at 60 ℃ for 2 hours, keeping the temperature at 80 ℃, stopping heating after uniformly mixing, naturally cooling, and sealing for storage;

(3) casting into a film: 54 parts of NCO-terminated polyurethane prepolymer, 43 parts of hydroxyl-terminated mixture, 681 parts of antioxidant Irgastab PUR, 0.3 part of light stabilizer UV-P, 0.5 part of thixotropic agent BYK-4100.2 and zinc neodecanoate catalyst are mixed in a casting machine, the mixture is cast on a transmission substrate through a die head, the transmission substrate is conveyed through a heating device channel for heating and curing, the thickness is set through rolling and curing for 3-5 min, after the setting degree is reached, the mixture is rolled and placed for 14d, polyurethane sheet material is obtained, and the performance of the polyurethane sheet material is tested.

According to the detection of GB/T528-2009 determination of tensile stress strain performance of vulcanized rubber or thermoplastic rubber, the tensile strength of the polyurethane rubber sheet material obtained by the comparative example at room temperature is 47MPa, the elongation at break is 880%, the tear strength is 51kN/m, the transmittance is 91%, and the haze is 0.5%.

The polyurethane film material obtained in the comparative example swells in tetrahydrofuran solvent and cannot be dissolved, which shows that the material has extremely high molecular weight and can be considered as a cross-linked thermosetting material.

The relevant test data of examples 1 to 3 and comparative examples 1 to 2 are shown in tables 5 and 6.

TABLE 5 tensile Strength of polyurethane film materials of examples 1-3 and comparative examples 1-2

TABLE 6 room temperature PC bond strengths of examples 1 to 3 and comparative examples 1 to 2

As can be seen from table 5 above, the temperature resistance of the polyurethane adhesive sheet materials of examples 1 to 3 is significantly better than that of the polyurethane adhesive sheet of comparative document 1, the tensile strength of the polyurethane film materials of examples 1-3 and comparative examples 1-2 are not substantially the same at room temperature, but in the process of gradually increasing from room temperature to 100 ℃, the tensile strength of the film material of comparative document 1 significantly decreased with the increase in temperature, particularly from room temperature to 50 c, the tensile strength of the film material of the comparison document 1 is rapidly reduced and becomes a viscous flow state at 100 ℃, and the tensile strength of the polyurethane film material of the embodiments 1-3 is similar to the change range of the film material of the comparison example 2 along with the increase of the temperature, which shows that the polyurethane film material of the embodiments 1-3 has better temperature resistance and is close to the tensile strength of the film material of the comparison example 2.

As can be seen from Table 6 above, the bonding strength between the polyurethane film material of examples 1-3 and PC is comparable to that of the film material of comparative example 1 at room temperature, and is significantly higher than that of the film material of comparative example 2.

As can be seen from fig. 2, 3 and 4, the polyurethane film materials of examples 1 to 3 have high molecular weight polyurethane and low molecular weight polyurethane, and the molecular weight of the high molecular weight polyurethane is greater than 40 ten thousand, and the molecular weight of the low molecular weight polyurethane is between 10 and 20 ten thousand, which is different from the molecular weight distribution of the PE399 polyurethane film of comparative example 1 corresponding to fig. 5.

In summary, the polyurethane film material of embodiments 1 to 3 has better temperature resistance on the premise that the bonding strength is equivalent to that of the low molecular weight film on the market, and the tensile strength can still reach or approach the tensile strength of the high molecular weight film along with the rise of the temperature.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.