TWI837844B - Method for producing liquid polycarbonate compound, and polyurethane - Google Patents

Abstract

The present application relates to a liquid polycarbonate compound and a method for producing the same, and polyurethane. The polycarbonate compound includes -COO- groups, thereby being equipped with more flexible mechanical properties, and further the formed polyurethane can have better flexibility and extensibility properties. The polyurethane formed from the polycarbonate compound of the present application can meet the requirements of molecular weight and mechanical properties.

Description

Method for producing liquid polycarbonate compound and polyurethane

The present invention relates to a polycarbonate compound, and in particular to a liquid polycarbonate compound with a high molecular weight, a method for preparing the same, and a polyurethane formed therefrom.

Polyurethane is a material with urethane groups in the main polymer chain. Based on its structural characteristics, polyurethane materials have excellent strength and processing properties and are widely used in various fields. However, the mechanical properties of polyurethane materials are relatively rigid and cannot meet other application areas that require good flexibility. Although some current methods use specific reactive monomers to adjust the mechanical properties of polyurethane, the selected reactive monomers are usually expensive, or the polyurethane produced still cannot have good flexibility and elongation, and needs further improvement.

In view of this, it is urgent to provide a liquid polycarbonate compound and a preparation method thereof and polyurethane to further improve the defects of the known polycarbonate compounds and polyurethanes.

Therefore, one aspect of the present invention is to provide a liquid polycarbonate compound having a specific content of -COO- groups, which can have both high molecular weight and relatively flexible mechanical properties, as well as good polyether compatibility.

Another aspect of the present invention is to provide a method for producing a liquid polycarbonate compound, which uses a specific polyether diol compound to carry out a condensation reaction to produce the aforementioned liquid polycarbonate compound. The reactor used excludes the setting of a distillation unit.

Another aspect of the present invention is to provide a polyurethane formed using the aforementioned liquid polycarbonate compound.

According to one aspect of the present invention, a liquid polycarbonate compound is proposed, which has a structure as shown in the following formula (I).

In formula (I), R represents a group derived from a polyether diol compound as shown in formula (II) below, and m represents an integer from 1 to 40. Wherein, based on 100 weight percent of the liquid polycarbonate compound, the content of -COO- group is 3 weight percent to 30 weight percent.

In formula (II), _R1 may represent a linear, branched, cyclic or aromatic alkylene group having 2 to 20 carbon atoms, or a polyoxyalkylene ether; _R2 and _R3 may independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a methyl alkyl ether, or a methyl alkenyl ether; n1 and n2 may represent integers from 0 to 15, respectively, and the sum of n1 and n2 is not less than 1.

According to some embodiments of the present invention, the molecular weight of the aforementioned liquid polycarbonate compound is 700 g/mole to 5000 g/mole.

According to some embodiments of the present invention, the aforementioned liquid polycarbonate compound is formed by the reaction of a carbonic acid compound and a polyether diol compound.

According to some embodiments of the present invention, the aforementioned carbonate compound includes ethylene carbonate and/or dimethyl carbonate.

According to some embodiments of the present invention, the molecular weight of the aforementioned polyether diol compound is 100 g/mole to 1000 g/mole.

According to another aspect of the present invention, a method for preparing a liquid polycarbonate compound is proposed. This method first adds a carbonate compound and a polyether diol compound shown in the following formula (II) into a reactor, wherein the reactor excludes the setting of a distillation unit.

In formula (II), _R1 may represent a linear, branched, cyclic or aromatic alkylene group having 2 to 20 carbon atoms, or a polyoxyalkylene ether; _R2 and _R3 may independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a methyl alkyl ether, or a methyl alkenyl ether; n1 and n2 may represent integers of 0 to 15, respectively, and the sum of n1 and n2 is not less than 1.

與一結構化合物，其中

係與聚醚二醇化合物之衍生物反應鍵結，以形成如下式(I)所示之液態聚碳酸酯化合物。 Then, the carbonic acid compound and the polyether diol compound are subjected to a condensation reaction. During the condensation reaction, the carbonic acid compound forms

and a structural compound, wherein

It reacts and bonds with a derivative of a polyether diol compound to form a liquid polycarbonate compound as shown in the following formula (I).

。 In formula (I), R represents a group derived from the polyether diol compound represented by formula (II); m represents an integer from 1 to 40. Wherein, based on 100 weight percent of the liquid polycarbonate compound, the liquid polycarbonate compound contains 3 weight percent to 30 weight percent of

.

According to some embodiments of the present invention, the molecular weight of the aforementioned liquid polycarbonate compound is 700 g/mole to 5000 g/mole.

According to some embodiments of the present invention, the pressure of the aforementioned reactor is 800 torr to 6000 torr.

According to some embodiments of the present invention, the aforementioned condensation reaction includes a first-stage reaction and a second-stage reaction. When the first-stage reaction is performed, the pressure of the reactor is 800 torr to 6000 torr, and when the second-stage reaction is performed, the pressure of the reactor is less than 760 torr.

According to some embodiments of the present invention, when the aforementioned first-stage reaction is carried out, the pressure of the reactor is 1000 torr to 5000 torr, and when the second-stage reaction is carried out, the pressure of the reactor is less than 400 torr.

According to some embodiments of the present invention, the aforementioned condensation reaction includes a first-stage reaction and a second-stage reaction. When the product of the first-stage reaction has a set molecular weight, a decompression operation is performed to carry out the second-stage reaction.

According to some embodiments of the present invention, the ratio of the molecular weight of the aforementioned liquid polycarbonate compound to the set molecular weight of the product is 1:0.1 to 1:0.6.

According to some embodiments of the present invention, the molar ratio of the aforementioned polyether diol compound to the carbonate compound is 1:0.2 to 1:4.0.

According to another aspect of the present invention, a polyurethane is proposed, which is formed by utilizing the aforementioned liquid polycarbonate compound, wherein the polyurethane has functions such as good flexibility, stretchability and better uniformity.

The liquid polycarbonate compound, the preparation method thereof and the polyurethane of the present invention are applied by introducing -COO- groups between the polymer chain segments of the polycarbonate compound, so that the polycarbonate compound has a specific content of -COO- groups, thereby having both a higher molecular weight and more flexible mechanical properties. Secondly, by introducing the -COO- groups, the polycarbonate compound of the present invention can be liquid and have better operability. The liquid polycarbonate compound of the present invention can be formed by a condensation reaction. By adjusting the conditions of the condensation reaction and the parameters of the reactor, the by-products generated in the condensation reaction can be effectively removed, so that the carbonic acid compound and the polyether diol compound have good reactivity, thereby obtaining the liquid polycarbonate compound of the present invention having a specific content of -COO- groups and a molecular weight. In addition, the liquid polycarbonate compound of the present invention can be further reacted to form a more flexible polyurethane with better elongation.

The manufacture and use of embodiments of the present invention are discussed in detail below. However, it is understood that the embodiments provide many applicable inventive concepts that can be implemented in a variety of specific contexts. The specific embodiments discussed are for illustration only and are not intended to limit the scope of the present invention.

The present invention provides a polyurethane, which is formed by reacting the liquid polycarbonate compound of the present invention with an isocyanate compound. The obtained polyurethane has better flexibility and elongation. Among them, the liquid polycarbonate compound of the present invention (having a structure shown in the following formula (I)) can be formed by reacting a polyether diol compound with a carbonate compound.

In formula (I), R represents a group derived from a polyether diol compound, and m represents an integer from 1 to 40.

)之含量為3重量百分比至30重量百分比，故所製得之聚氨酯兼具較佳之柔韌性與延伸性。在其他具體例中，聚碳酸酯化合物的數目平均分子量較佳可為750至3000。 In some embodiments, the polycarbonate compound has a number average molecular weight of 700 g/mole to 5000 g/mole, and based on 100 weight percent of the polycarbonate compound, the -COO- group (

) content is 3 weight percent to 30 weight percent, so the obtained polyurethane has better flexibility and elongation. In other specific examples, the number average molecular weight of the polycarbonate compound is preferably 750 to 3000.

The polyether diol compound may include but is not limited to the compound shown in the following formula (II), other suitable polyether diol compounds, or any combination of the above compounds.

In formula (II), _R1 may represent a linear, branched, cyclic or aromatic alkylene group having 2 to 20 carbon atoms, or a polyoxyalkylene ether; _R2 and _R3 may independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a methyl alkyl ether (the alkyl group has 1 to 8 carbon atoms), or a methyl alkenyl ether (the alkenyl group has 2 to 4 carbon atoms); n1 and n2 may represent integers of 0 to 15, respectively, and the sum of n1 and n2 is not less than 1.

For example, _R1 can be, for example, an ethyl group, a 1,3-propyl group, a 2-methyl-1,3-propyl group, a 2,2-dimethyl-1,3-propyl group, a 1,4-butyl group, a 2-methyl-1,4-butyl group, a 1,5-pentyl group, a 3-methyl-1,5-pentyl group, a 1,6-hexyl group, a 1,7-heptyl group, a 1,8-octyl group, a 1,9-nonyl group, a 1,10-decyl group, a 1,12-dodecyl group, a 1,4-cycloheptyl group, a 1,4-cyclohexyl group, a 1,3-cyclopentyl group, a p-phenol bisethanol ether group, a bisphenol A bisethanol ether group, a bisphenol A diisopropyl alcohol ether group, a divalent functional group derived from a polyoxyalkyl ether (such as a polyoxyethylene ether, a polyoxypropylene ether and/or a polyoxyethylene polyoxypropylene ether), and/or other appropriate groups. _R2 and _R3 can be independently, for example, a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, an ethyl ether, an ethyl propyl group, an ethyl butyl group, an ethyl 2-ethylhexyl group, an ethyl allyl group, and/or other appropriate groups.

In some embodiments, the number average molecular weight of the polyether diol compound is 100 g/mole to 1000 g/mole, preferably 150 g/mole to 900 g/mole, and more preferably 180 g/mole to 850 g/mole. When the number average molecular weight of the polyether diol compound is within the aforementioned range, the obtained polycarbonate compound may have an appropriate content of -COO- groups and have both high molecular weight and better flexibility.

))即可。在一些具體例中，碳酸化合物可包含但不限於碳酸乙烯酯、碳酸丙烯酯、碳酸丁烯酯、碳酸二甲酯、碳酸二乙酯、碳酸二丙酯、碳酸二丁酯、碳酸二戊酯、碳酸二己酯、碳酸二辛酯、碳酸二苯酯、碳酸二萘酯、其他適當之碳酸化合物，或上述化合物之任意混合。 The aforementioned carbonate compound is not particularly limited, and it only needs to be able to react with the polyether diol compound to form an ester group in the polycarbonate compound (i.e., a -COO- group in the polycarbonate compound (

In some specific examples, the carbonate compound may include but is not limited to ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, dipentyl carbonate, dihexyl carbonate, dioctyl carbonate, diphenyl carbonate, dinaphthyl carbonate, other appropriate carbonate compounds, or any mixture of the above compounds.

The preparation of the polycarbonate compound of the present invention is to add the aforementioned polyether diol compound and the carbonic acid compound into a reactor to carry out a condensation reaction to form the polycarbonate compound. In some embodiments, the condensation reaction is carried out at 120° C. to 220° C., and the reaction time can be 6 hours to 48 hours. However, the present invention is not limited thereto. In other embodiments, the temperature and reaction time of the condensation reaction can be appropriately adjusted according to the type and content of the selected polyether diol compound and the carbonic acid compound to react and form the polycarbonate compound of the present invention. Based on the usage of 1 mol of the polyether diol compound, the usage of the carbonic acid compound is 0.2 mol to 4 mol, and preferably 0.5 mol to 3 mol. When the amount of the carbonate compound is within this range, the polycarbonate compound obtained can have a specific content of -COO- groups, and the mechanical properties of the polycarbonate compound can be adjusted.

基團外，碳酸化合物中之剩餘基團亦可形成結構化合物。其中，由於低碳數(如碳數不大於6)之碳酸化合物具有較快之縮合反應性，故低碳數之碳酸化合物於反應時易生成結構化合 物。此些結構化合物易與碳酸化合物反應，而降低聚醚二醇化合物與碳酸化合物之反應性，進而降低聚碳酸酯化合物的產率。據此，此些結構化合物即為縮合反應不欲形成之副產物。須說明的是，於後續內容中，此些結構化合物係簡稱為副產物。基於所選用之碳酸化合物的種類，所生成之副產物亦有所不同。舉例而言，當碳酸化合物為碳酸烯酯時，具有最少碳數之碳酸乙烯酯(碳數為3)經反應可形成乙二醇之氣態副產物，且乙二醇亦會與碳酸化合物產生反應，進而降低聚醚二醇化合物與碳酸化合物之反應性，且影響所欲具有特定分子量之聚碳酸酯化合物的生成；當碳酸化合物為碳酸二酯時，具有最少碳數之碳酸二甲酯(碳數為3)經反應可形成甲醇之氣態副產物，進而影響聚醚二醇化合物與碳酸化合物之反應性，以及所欲具有特定分子量之聚碳酸酯化合物的生成。 When the condensation reaction is carried out, the carbonic acid compound can form the aforementioned polycarbonate compound through the electron transfer of the covalent bond.

In addition to the carbonic acid groups, the remaining groups in the carbonate compound can also form structured compounds. Among them, since the carbonate compounds with low carbon numbers (such as carbon numbers not greater than 6) have faster condensation reactivity, the carbonate compounds with low carbon numbers are easy to generate structured compounds during the reaction. These structured compounds are easy to react with carbonate compounds, thereby reducing the reactivity of polyether diol compounds and carbonate compounds, and further reducing the yield of polycarbonate compounds. Accordingly, these structured compounds are the by-products that are not intended to be formed by the condensation reaction. It should be noted that in the subsequent content, these structured compounds are simply referred to as by-products. Based on the type of carbonate compound selected, the by-products generated are also different. For example, when the carbonate compound is an alkylene carbonate, ethylene carbonate (carbon number is 3) having the least carbon number can react to form a gaseous byproduct of ethylene glycol, and ethylene glycol will also react with the carbonate compound, thereby reducing the reactivity of the polyether diol compound and the carbonate compound, and affecting the formation of the desired polycarbonate compound with a specific molecular weight; when the carbonate compound is a diester carbonate, dimethyl carbonate (carbon number is 3) having the least carbon number can react to form a gaseous byproduct of methanol, thereby affecting the reactivity of the polyether diol compound and the carbonate compound, and the formation of the desired polycarbonate compound with a specific molecular weight.

In some embodiments, the reactor for the condensation reaction may be a high-pressure reactor without a refining unit (such as an industrial equipment refining tower, distillation tower, fractionation tower, packed tower, and/or other similar equipment), which can reduce the complexity of the reaction process. Since the refining unit is not used, the internal pressure of the reactor is adjusted during the reaction process to remove the byproducts produced by the condensation reaction, thereby ensuring that the polyether diol compound and the carbonate compound can maintain good reactivity. In some embodiments, the pressure of the reactor may be 800 torr to 6000 torr, preferably 1000 torr to 5000 torr, and more preferably 2000 torr to 4000 torr. In some embodiments, the aforementioned condensation reaction can be divided into multiple stages to facilitate the removal of by-products. In the initial stage of the condensation reaction, the polyether diol compound and the carbonate compound can react to form oligomers, and the pressure of the reactor can be 800 torr to 6000 torr. Then, the pressure of the reactor is adjusted to less than 760 torr to facilitate the condensation reaction between the oligomers to form the polycarbonate compound of the present invention. Preferably, the initial pressure of the reactor can be 1000 torr to 5000 torr, and when the aforementioned oligomer condensation is performed, the pressure of the reactor is adjusted to less than 400 torr. In other embodiments, at the initial stage of the condensation reaction, the pressure of the reactor may be 800 torr to 6000 torr, so that the polyether diol compound and the carbonate compound can react to form an oligomer. Preferably, the pressure of the reactor may be 1000 torr to 5000 torr, so as to facilitate the formation of the oligomer. When the molecular weight of the polycarbonate compound to be prepared is in the ratio of 1:0.1 to 1:0.6 to the molecular weight of the oligomer, the pressure of the reactor is reduced to less than 760 torr, so as to facilitate the removal of by-products. Preferably, the pressure of the reactor may be reduced to 400 torr. It is understandable that during the initial condensation reaction, the generation of byproducts will increase the pressure of the reactor, and by reducing the subsequent pressure, the byproducts in the reactor can be removed more effectively, thereby improving the reactivity between the polyether diol compound and the carbonate compound.

In addition, by adjusting the reaction conditions and/or reactor parameters (e.g., the molar ratio of the polyether diol compound to the carbonate compound, the temperature of the condensation reaction, the amount of catalyst, and/or other conditions), it is also helpful to remove by-products and reduce their interference with the condensation reaction, thereby ensuring that the polycarbonate compound produced has a specific molecular weight and contains a specific content of -COO- groups. In some specific examples, the molar ratio of the polyether diol compound to the carbonate compound can be, for example, 1:0.2 to 1:4.0, and preferably 1:0.5 to 1:3.0; the temperature of the condensation reaction can be, for example, 120°C to 220°C, and preferably 140°C to 200°C; the amount of catalyst can be, for example, 10 ppm to 10000 ppm, and preferably 10 ppm to 1000 ppm. When the molar ratio of the polyether diol compound to the carbonate compound, the temperature of the condensation reaction, and/or the amount of the catalyst are within the aforementioned range, the byproducts of the carbonate compound can be effectively removed, thereby ensuring the reactivity between the carbonate compound and the polyether diol compound, thereby increasing the yield of the polycarbonate compound of the present invention. In other embodiments, the removal of the byproducts can also be achieved by other methods, but it should be noted that the polycarbonate compound obtained by the reaction must have a specific molecular weight and contain a specific amount of -COO- groups.

In some embodiments, when the condensation reaction is carried out, the corresponding catalyst is added to the reactor to improve the reaction efficiency. In some specific examples, the catalyst may include but is not limited to metal elements such as lithium, sodium, potassium, cadmium, cadmium, magnesium, calcium, strontium, barium, titanium, cobalt, nickel, zinc, germanium, arsenic, zirconium, aluminum, tin, lead, antimony, and arsenic; metal oxides, metal hydroxides, metal salts, metal alkoxides or metal organic compounds of the aforementioned metal elements; other appropriate catalyst materials; or any mixture of the above catalysts. The amount of catalyst used is 10ppm to 10000ppm to the total amount of raw materials, and preferably 10ppm to 1000ppm.

In the polycarbonate compound of the present invention, the polycarbonate compound may have different contents of -COO- groups based on the selection of the polyether diol compound. For example, when the polyether diol compound represented by the aforementioned formula (II) is used, and its number average molecular weight is 100 g/mole to 1000 g/mole, the formed 100 weight percent of the polycarbonate compound (as shown in the following formula (I-1)) has 3 weight percent to 30 weight percent of -COO- groups.

In formula (I-1), R ₁ , R ₂ , R ₃ , n1, n2 and m are defined as above and will not be further described herein.

In the obtained polycarbonate compound, the introduction of -COO- groups can form a similar interruption effect on the polymer chain segment of the polycarbonate compound, so that the polycarbonate compound can remain in a liquid state despite having a higher molecular weight, thereby improving its operability and facilitating the preparation of polyurethane with both flexibility and extensibility. Accordingly, if the content of -COO- groups in the polycarbonate compound is not within the aforementioned range of the present invention, too few -COO- groups will reduce the aforementioned interruption effect, and the subsequently formed polyurethane will not have a flexible property; too many -COO- groups can greatly improve the aforementioned interruption effect, but the polymer chain segment of the polycarbonate compound will also be shortened, thereby reducing the extensibility and mechanical strength of the formed polyurethane, and it is difficult to meet the application requirements. It is understandable that the interruption of the aforementioned polymer chain segment refers to the interruption of the repeating units of the polymer chain segment, rather than the actual interruption of the covalent bond. In other words, each polymer chain of the formed polycarbonate compound can be formed by several low molecular weight polymer chain segments, and these polymer chain segments are covalently bonded by -COO- groups.

In some application examples, the present invention introduces -COO- groups into polycarbonate compounds, so that -COO- groups are covalently bonded between polymer chain segments, thereby increasing the molecular weight of the liquid polycarbonate compound and making it have better flexibility. Secondly, when the liquid polycarbonate compound with a specific -COO- group content is used to prepare polyurethane, the obtained polyurethane has not only a higher molecular weight, but also better flexibility, elongation and uniformity. In addition, by adjusting the conditions of the condensation reaction and the parameters of the reactor, the byproducts formed by the carbonate compound in the condensation reaction can be effectively removed, which helps to maintain the reactivity between the carbonate compound and the polyether diol compound, thereby increasing the yield of the liquid polycarbonate compound with a specific molecular weight and a specific content of -COO- groups.

The following examples are used to illustrate the application of the present invention, but they are not used to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention.

Preparation of polycarbonate compounds

Embodiment 1 to Embodiment 3

Implementation Example 1

In a 2L stainless steel reactor equipped with a stirrer, a thermometer and a nitrogen inlet tube, 1000g of alkyl polyether diol (number average molecular weight is 200g/mol), 990g of dimethyl carbonate and 1g of tetrabutoxytitanium catalyst were added. After nitrogen replacement, the temperature in the reactor was raised to 185°C under stirring to carry out the condensation reaction. First, the pressure was reduced to 50torr to 200torr for 10 hours, and then the pressure was reduced to 50torr to 200torr. After the reaction was continued for 4 hours, the temperature in the reactor was reduced to room temperature to obtain the polycarbonate compound (PCDO-1, viscous liquid) of Example 1, and its hydroxyl value was 58.6mgKOH/g, and the -COO- group content was about 17%.

To further confirm that the polycarbonate compound of the present invention can be uniformly mixed with the polyether diol compound and react with the isocyanate functional organic compound to form polyurethane, the polycarbonate compound prepared in Example 1 was mixed with polyether diol compounds such as PTMEG, PEG and PPG at a mixing ratio of 1:9 to 9:1 at 80°C, and after mixing at the temperature for 8 hours, the appearance change was observed visually, and the results are shown in the following table, where "◎" represents that the mixed solution is uniformly mixed, "○" represents that the mixed solution is slightly turbid, "×" represents that the mixed solution is stratified, and "△" represents that the appearance of the mixed solution is between slightly turbid (○) and stratified (×).

In addition, the same test was conducted with a commercially available product (polycarbonate compound model UH200 manufactured by UBE Corporation), and the mixture with PTMEG1000 or PTMEG2000 was layered and did not have good miscibility.

Accordingly, the polycarbonate compound of the present invention can be well mixed with the polyether diol compound and can further react to form polyurethane.

Example 2

In a 2L stainless steel reactor equipped with a stirrer, a thermometer and a nitrogen inlet tube, 1000g of polyoxypropylene ether glycol (number average molecular weight of 400g/mol), 135g of dimethyl carbonate and 0.6g of tetrabutoxy titanium catalyst were added. After nitrogen replacement, the temperature in the reactor was raised to 160°C under stirring to carry out the condensation reaction. First, the pressure was reduced to 50torr to 200torr for 7 hours, and then the pressure was reduced to 50torr to 200torr. After the reaction was continued for 5 hours, the temperature in the reactor was reduced to room temperature to obtain the polycarbonate compound (PCDO-2, viscous liquid) of Example 2, and its hydroxyl value was 106.9mgKOH/g, and the -COO- group content was about 6%.

Example 3

In a 3L stainless steel reactor equipped with a stirrer, a thermometer and a nitrogen inlet pipe, 1000g of methyl propylene glycol polyether (number average molecular weight of 130g/mol), 1400g of dimethyl carbonate and 0.9g of tetrabutoxy titanium catalyst were added. After nitrogen replacement, the temperature in the reactor was raised to 175°C under stirring to carry out the condensation reaction. First, the pressure was reduced to 50torr to 200torr for 10 hours, and then the pressure was reduced to 50torr to 200torr. After the reaction was continued for 6 hours, the temperature in the reactor was reduced to room temperature to obtain the polycarbonate compound (PCDO-3, viscous liquid) of Example 3, and its hydroxyl value was 28.5mgKOH/g, and the -COO- group content was about 27%.

The polycarbonate compound obtained in Example 2 and Example 3 can also be well mixed with the specific polyether diol compound, which helps the reaction between the two, so it can further react to form a polyurethane with both more flexible mechanical properties and better elongation and uniformity.

Accordingly, the liquid polycarbonate compound of the present invention is prepared by condensing a polyether diol compound with a carbonate compound, and the -COO- group derived from the carbonate compound can be covalently bonded between the polymer chain segments derived from the polyether diol compound, so that it has a specific content of -COO- groups, and the obtained liquid polycarbonate compound has a higher molecular weight and more flexible mechanical properties. Among them, due to the introduction of the -COO- group, the polycarbonate compound obtained by the reaction can be a liquid compound, so it has better operability. Furthermore, the liquid polycarbonate compound of the present invention can be further reacted to obtain polyurethane, and the polyurethane has more flexible mechanical properties and better elongation and uniformity, so it can meet the application requirements. In addition, by controlling the conditions of the condensation reaction and the parameters of the reactor, the byproducts produced by the carbonate compound during the condensation reaction can be effectively removed, thereby avoiding the loss of the carbonate compound by the byproducts, thereby helping to maintain the reactivity between the carbonate compound and the polyether diol compound, thereby increasing the yield of the liquid polycarbonate compound of the present invention that has both flexibility and extensibility.

Although the present invention has been disclosed in the form of implementation as above, it is not intended to limit the present invention. Anyone with common knowledge in the technical field to which the present invention belongs can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of the patent application attached hereto.

Claims (8)

A method for preparing a liquid polycarbonate compound comprises: adding a carbonate compound and a polyether diol compound represented by the following formula (II) into a reactor, wherein the reactor excludes a distillation unit;

In formula (II), _R1 can represent a linear, branched, cyclic or aromatic alkylene group with a carbon number of 2 to 20, or a polyoxyalkylene ether; _R2 and _R3 can independently represent a hydrogen atom, an alkyl group with a carbon number of 1 to 8, a methyl alkyl ether, or a methyl alkenyl ether; n1 and n2 can represent integers of 0 to 15, respectively, and the sum of n1 and n2 is not less than 1; and a condensation reaction is carried out on the carbonate compound and the polyether diol compound, and during the condensation reaction, the carbonate compound forms

and a structural compound, wherein the structural compound is formed by the carbonate compound

After that, the remaining group is derived from the compound, and

It reacts and bonds with a derivative of the polyether diol compound to form the liquid polycarbonate compound represented by the following formula (I);

In formula (I), R represents a group derived from the polyether diol compound represented by formula (II); m represents an integer from 1 to 40; wherein based on 100 weight percent of the liquid polycarbonate compound, the liquid polycarbonate compound contains 3 weight percent to 30 weight percent of

. A method for preparing a liquid polycarbonate compound as described in claim 1, wherein a molecular weight of the liquid polycarbonate compound is 700 g/mole to 5000 g/mole. The method for preparing a liquid polycarbonate compound as described in claim 1, wherein the condensation reaction comprises: performing a first-stage reaction, wherein the pressure of the reactor during the first-stage reaction is 800 torr to 6000 torr; and performing a second-stage reaction after the first-stage reaction, wherein the pressure of the reactor during the second-stage reaction is less than 760 torr. The method for producing a liquid polycarbonate compound as described in claim 3, wherein the pressure of the reactor during the first stage reaction is 1000 torr to 5000 torr, and the pressure of the reactor during the second stage reaction is less than 400 torr. The method for preparing a liquid polycarbonate compound as described in claim 1, wherein the condensation reaction comprises: performing a first-stage reaction; and when a product of the first-stage reaction has a set molecular weight, performing a decompression operation to perform a second-stage reaction. A method for preparing a liquid polycarbonate compound as described in claim 5, wherein a ratio of a molecular weight of the liquid polycarbonate compound to a set molecular weight of the product is 1:0.1 to 1:0.6. The method for preparing a liquid polycarbonate compound as described in claim 1, wherein the molar ratio of the polyether diol compound to the carbonate compound is 1:0.2 to 1:4.0. A polyurethane formed by a liquid polycarbonate compound, wherein the liquid polycarbonate compound is prepared by the preparation method described in any one of claims 1 to 7.