Polyester plasticizer having high cold resistance and polyvinyl chloride composition comprising the same

Abstract

This invention discloses a polyester plasticizer with high cold resistance and a polyvinyl chloride (PVC) composition comprising the same. The polyester plasticizer of this invention is obtained by esterification of a diacid component and a diol component, followed by end-capping with a capping agent. The diacid component is sebacic acid, and the diol component comprises a first diol component and a second diol component. The first diol component is diethylene glycol, and the second diol component is a diol having a silicon-oxygen structural unit, a diol having a linear structure, or a diol having a branched chain structure. Therefore, the polyester plasticizer of this invention can be applied to PVC compositions to improve the low-temperature resistance and flexural strength of flexible PVC products, as well as reduce oil seepage.

Description

Technical Field

[0001] This invention relates to a polyester plasticizer and its application, and more particularly to a polyester plasticizer with high cold resistance and a polyvinyl chloride composition comprising the same. Background Technology

[0002] For thermoplastics, plasticizers are important additives that improve the flowability and plasticity of the plastic during processing and molding. It is well known that plasticizers are inextricably linked to polyvinyl chloride (PVC) plastics; by adding plasticizers, PVC plastics can be made into flexible PVC products such as films and sheets.

[0003] There are many types of plasticizers. Among them, phthalate plasticizers such as DEHP, DBP, BBP, DINP, DIDP, and DNOP are restricted due to concerns about toxicity. Currently, some manufacturers are using polyester plasticizers as a substitute. However, polyester plasticizers are prone to precipitation in practical applications, which adversely affects the appearance, physical properties, and mechanical properties of subsequently processed products.

[0004] In addition, soft PVC products (such as PVC rubber) are generally not suitable for extremely low temperature environments. They become harder and more brittle in extremely low temperature environments, and are prone to cracking and breakage during use.

[0005] In summary, these flexible PVC products may experience plasticizer exudation (oil seepage) during use, and in some aspects, such as low-temperature resistance and flexural strength, they may not meet the required performance. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a polyester plasticizer with high cold resistance and a polyvinyl chloride composition including the same, addressing the shortcomings of existing technologies. The concept of this invention is to use sebacic acid and diethylene glycol, along with a diol having silicon-oxygen structural units, a linear structure, or a branched chain structure, to carry out an esterification reaction, thereby improving the cold resistance and durability of the polyester plasticizer in plasticized products, and enabling soft PVC products to maintain flexibility at low temperatures.

[0007] To solve the above-mentioned technical problems, one of the technical solutions adopted by the present invention is to provide a polyester plasticizer with high cold resistance, which is obtained by esterification reaction of diacid component and diol component and end-capping with end-capping agent. The diacid component is sebacic acid, and the diol component includes a first diol component and a second diol component. The first diol component is diethylene glycol, and the second diol component is a diol with silicon-oxygen structural unit, a diol with a straight chain structure, or a diol with a branched chain structure.

[0008] In a feasible or optional embodiment of the present invention, the polyester plasticizer with high cold resistance has a structure as shown in Formula I:

[0009]

[0010] In Formula I, A represents a residue of sebacic acid; B1 and B2 each independently represent residues of the first diol component or the second diol component; n is a positive integer from 1 to 4.

[0011] In a feasible or optional embodiment of the present invention, the diol having silicon-oxygen structural units has the structure shown in Formula II:

[0012]

[0013] In Formula II, Me represents methyl. Furthermore, the diol with a straight-chain structure is dodecanediol, and the diol with a branched-chain structure is 2-butyl-2-ethyl-1,3-propanediol; n is a positive integer from 1 to 12.

[0014] In feasible or optional embodiments of the present invention, the second diol component is a diol having a silicon-oxygen structural unit; and in Formula I, B1 and B2 each independently represent residues of diethylene glycol or residues derived from the diol having a silicon-oxygen structural unit.

[0015] In feasible or optional embodiments of the present invention, the second diol component is a diol having a straight-chain structure; and in Formula I, B1 and B2 each independently represent residues of diethylene glycol or residues derived from the diol having a straight-chain structure.

[0016] In feasible or optional embodiments of the present invention, the second diol component is a diol having a branched chain structure; and in Formula I, B1 and B2 each independently represent residues of diethylene glycol or residues derived from the diol having a branched chain structure.

[0017] In feasible or optional embodiments of the present invention, the capping agent is an acid-based capping agent or an alcohol-based capping agent.

[0018] In a feasible or optional embodiment of the present invention, the capping agent is lauric acid.

[0019] To address the aforementioned technical problems, another technical solution adopted by the present invention is to provide a polyvinyl chloride composition for manufacturing flexible articles. The polyvinyl chloride composition comprises 100 parts by weight of polyvinyl chloride, a plasticizer, a stabilizer, and at least inorganic additives, wherein the plasticizer comprises a polyester plasticizer with high cold resistance as described above.

[0020] In feasible or optional embodiments of the present invention, the plasticizer component further comprises C9-C11 phthalate, and the addition ratio of the C9-C11 phthalate to the polyester plasticizer with high cold resistance is 3:1.

[0021] In general, the polyester plasticizer with high cold resistance provided by the present invention contains sebacic acid residues and diethylene glycol residues linked to sebacic acid residues in its molecular backbone, as well as diol residues with silicon-oxygen structural units (e.g., silicon-oxygen bonds or silicon-oxygen chains), or diol residues with straight-chain structures (e.g., dodecanediol residues), or diol residues with branched-chain structures (e.g., 2-butyl-2-ethyl-1,3-propanediol residues). Therefore, it has excellent cold resistance and migration resistance, and can be applied to polyvinyl chloride compositions to improve the low-temperature resistance, flexural strength, and oil exudation of PVC flexible products.

[0022] To further understand the features and technical content of the present invention, please refer to the following detailed description and accompanying drawings. However, the drawings provided are for reference and illustration only and are not intended to limit the present invention. Attached Figure Description

[0023] Figure 1 This is a flowchart of a method for manufacturing the reinforced plastic extrusion of the present invention. Detailed Implementation

[0024] The following specific embodiments illustrate the implementation of the invention regarding "a polyester plasticizer with high cold resistance and a polyvinyl chloride composition comprising the same". Those skilled in the art can understand the advantages and effects of the invention from the content disclosed in this specification. The invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the invention. Furthermore, the accompanying drawings are for simple illustrative purposes only and are not depictions of actual dimensions, as stated beforehand. The following embodiments will further describe the relevant technical content of the invention in detail, but the disclosed content is not intended to limit the scope of protection of the invention.

[0025] It should be understood that while terms such as "first," "second," and "third" may be used in this document to describe various components or signals, these components or signals should not be limited by these terms. These terms are primarily used to distinguish one component from another, or one signal from another. Furthermore, the term "or" as used in this document should, depending on the context, include any combination of one or more related listed items.

[0026] Unless otherwise defined, the terms used herein have the same meaning as commonly understood by those skilled in the art. Materials involved in the embodiments are commercially available or made according to prior art, unless otherwise specified. Methods or operations involved in the embodiments are conventional methods or operations in the art, unless otherwise specified.

[0027] PVC materials have a wide range of applications, and with the addition of plasticizers, they can be made into flexible PVC products such as films and sheets. However, these flexible PVC products may experience plasticizer exudation (oil seepage) during use, and in some aspects, such as low-temperature resistance and flexural strength, they may not meet the required performance. Therefore, this invention provides a polyester plasticizer with high cold resistance, the main chain of which contains repeating units derived from diacids with long carbon chains and diols with silicon-oxygen structures, straight-chain structures, and / or branched-chain structures. Therefore, the polyester plasticizer of this invention improves cold resistance, migration resistance, and extraction resistance, and enhances the low-temperature flexural strength of flexible PVC products.

[0028] Polyester plasticizer with high cold resistance

[0029] In this invention, the polyester plasticizer is obtained through esterification of a diacid component and a diol component, followed by end-capping with a capping agent. The diacid component suitable for this invention can be selected from aliphatic diacids, and may also be sebacic acid. The diol component suitable for this invention may include a first diol component and a second diol component. The first diol component is diethylene glycol, and the second diol component is a diol having a silicon-oxygen structural unit, a diol having a straight-chain structure, or a diol having a branched-chain structure. Therefore, the polyester plasticizer of this invention has a large molecular weight and can introduce silicon-oxygen structural units (e.g., silicon-oxygen bonds or silicon-oxygen chains) and one of long carbon chain side chains or branched side chains into the molecular backbone, thereby improving the low-temperature resistance and flexural strength of PVC flexible products, as well as reducing oil seepage.

[0030] Furthermore, the weight-average molecular weight of the polyester plasticizer of the present invention is in the range of 2000 g / mol to 5000 g / mol. The polyester plasticizer of the present invention has the structure shown in Formula I:

[0031]

[0032] In Formula I, A represents a residue of an aliphatic diacid, such as a sebacic acid residue; B1 and B2 each independently represent residues of the first or second diol component, wherein the first diol component is a diethylene glycol residue, and the second diol component is a diol residue with a silicon-oxygen structural unit, a diol residue with a straight chain structure, or a diol residue with a branched chain structure; n is a positive integer from 1 to 4.

[0033] It should be noted that the diol components involved in the esterification reaction include two different diols: diethylene glycol and a diol with silicon-oxygen structural units, a straight-chain structure, or a branched-chain structure. Therefore, residues of both diols are present in the structure shown in Formula I. For example, in Formula I, the structural units (monomer units) of A and B1 can constitute a repeating unit, where B1 in one of the repeating units represents a diethylene glycol residue, and B2 represents a residue of a diol with silicon-oxygen structural units, a straight-chain structure, or a branched-chain structure.

[0034] In embodiments of the present invention, the polyester plasticizer comprises 100 mol% diacid residues and 100 mol% diol residues. As the second diol component, the diol having a silicon-oxygen structural unit may optionally have the structure shown in Formula II:

[0035]

[0036] In Formula II, Me represents methyl; n is a positive integer from 1 to 12.

[0037] In embodiments of the present invention, the diol having a straight-chain structure may be selected as dodecanediol (1,12-Dodecanediol) as the second diol component.

[0038] In embodiments of the present invention, the diol having a branched chain structure may be selected as 2-butyl-2-ethyl-1,3-propanediol (BEPD) as the second diol component.

[0039] Method for producing polyester plasticizers with high cold resistance

[0040] Please see Figure 1 This describes the steps involved in producing a polyester plasticizer with high cold resistance, as described in this invention. Figure 1 As shown, the polyester plasticizer with high cold resistance of the present invention can be made by the following steps: feeding step S1, esterification reaction step S2, end-capping reaction step S3, and vacuum purification step S4.

[0041] In the feeding step S1, the diacid component, diol component and catalyst are first added to the reactor to form a reaction system, wherein the mass ratio of the diol component to the diacid component can be 1.1-1.3:1; the catalyst can be, but is not limited to, a titanium catalyst, such as tetrabutyl titanate (TNBT).

[0042] In esterification step S2, the reaction system can undergo esterification in two different temperature ranges while simultaneously refluxing. Step S3 proceeds when the acid value is detected to be less than 100 mg KOH / g. The first temperature range is 120°C to 150°C, and the second temperature range is 190°C to 220°C, with an average heating rate of 20°C / hour. Depending on the requirements, there can be more than two temperature ranges for esterification step S2, arranged in ascending order of temperature.

[0043] In the capping reaction step S3, a capping agent is added to the reactor to cap the esterification reaction product. During this process, reflux is maintained. When the acid value is detected to be less than 30 mg KOH / g, step S4 is carried out. The amount of capping agent added can be 10% to 20% of the total mass of the reaction system, and the capping reaction temperature is controlled in the range of 150°C to 180°C.

[0044] In the vacuum purification step S4, the crude ester product obtained in step S3 is subjected to vacuum distillation to remove unwanted components from the crude ester product under conditions of pressure below 760 Torr and temperature of 150°C to 180°C, thereby obtaining the polyester plasticizer of the present invention. In practical applications, the vacuum purification step S4 can be carried out in a pressure range of 10 Torr to 750 Torr. Depending on the needs, the pressure range of the vacuum purification step S4 can be divided into multiple ranges ordered from high to low pressure.

[0045] Polyvinyl chloride composition

[0046] This invention provides a polyvinyl chloride (PVC) composition, which mainly comprises 100 parts by weight of PVC, a plasticizer, a stabilizer, and at least one inorganic additive. Notably, the plasticizer comprises a polyester plasticizer with high cold resistance as described above. Therefore, soft products such as rubber sheets made from the PVC composition of this invention are suitable for extremely low-temperature regions or environments (such as cold storage rooms).

[0047] In embodiments of the present invention, the plasticizer component may further include C9-C11 phthalate (911P), which is formed by esterification of C9-C11 mixed alcohols and phthalic anhydride, and has excellent cold-resistant properties; and the addition ratio of C9-C11 phthalate to the polyester plasticizer with high cold resistance as described above is 3:1. Optionally, the stabilizer is a barium zinc stabilizer, and the inorganic additive is calcium carbonate.

[0048] As needed, the polyvinyl chloride composition of the present invention may further include at least one functional additive, such as, but not limited to, lubricants, antioxidants, UV absorbers, impact modifiers, processing aids, and colorants.

[0049] Example 1

[0050] According to the formulation and dosage in Table 1, sebacic acid, Diol-A (a diol with the structure shown in Formula II), diethylene glycol, and tetrabutyl titanate were added to the esterification reactor, and a phosphorus-containing antioxidant (TPP) was added to the resulting reaction system. The reaction system then underwent esterification in the reactor. The reactor temperature was first raised to 120°C and held for 1 hour, then stepped up to 200°C and held for 3 hours. When the acid value was detected to be less than 100 mg KOH / g, lauric acid, an acidic end-capping agent, was added to the reactor to end-cap the esterification product. The end-capping reaction was terminated when the acid value was detected to be less than 30 mg KOH / g. Subsequently, the crude ester product was subjected to vacuum distillation under the following conditions: the reactor pressure was reduced to 50 Torr, the temperature was reduced to below 180°C, and the nitrogen flow rate was controlled at 100 Nm³. 3 / Hr. When the acid value is detected to be less than 1 mg KOH / g, a high molecular weight polyester plasticizer is obtained.

[0051] Example 2

[0052] As in Example 1, Diol-A was replaced with dodecanediol, and the polymeric polyester plasticizer was prepared under the same operating conditions according to the formulation and dosage in Table 1.

[0053] Example 3

[0054] As in Example 1, Diol-A was replaced with 2-butyl-2-ethyl-1,3-propanediol, and the polymeric polyester plasticizer was prepared under the same operating conditions according to the formulation dosage in Table 2.

[0055] Example 4

[0056] As in Example 1, diethylene glycol was replaced with neopentyl glycol (NPG), and the polymeric polyester plasticizer was prepared under the same operating conditions according to the formulation and dosage in Table 2.

[0057] Example 5

[0058] As in Example 1, diethylene glycol was replaced with 2-methyl-1,3-propanediol (MPO), and the polymeric polyester plasticizer was prepared under the same operating conditions according to the formulation dosage in Table 2.

[0059] Example 6

[0060] As in Example 1, diethylene glycol was used alone as the diol component, and 2-ethylhexanol (2-EH), an alcohol-based end-capping agent, was used to replace the acid-based end-capping agent. The polymeric polyester plasticizer was prepared under the same operating conditions according to the formulation dosage in Table 3.

[0061] Example 7

[0062] As in Example 1, diethylene glycol was used alone as the diol component, and the polymeric polyester plasticizer was prepared under the same operating conditions according to the formulation dosage in Table 3.

[0063] Comparative example

[0064] As in Example 1, adipic acid was used as the diacid component, a combination of 2-methyl-1,3-propanediol (MPO) and neopentyl glycol (NPG) was used as the diol component, and 2-ethylhexanol (2-EH) was used as the end-capping agent. The polymeric polyester plasticizer was prepared under the same operating conditions according to the formulation dosage in Table 1.

[0065] The polyester plasticizers of Examples 1-7 and the Comparative Examples were combined with C9-C11 phthalate (911P) and added to polyvinyl chloride (polyester plasticizer: 911P = 1:3), along with appropriate amounts of inorganic filler calcium carbonate and barium zinc stabilizer. The resulting polyvinyl chloride compositions were prepared into samples, and their glass transition temperature, low-temperature flexural strength, and plasticizer retention properties were tested. The test methods are described below, and the test results are summarized in Tables 1 to 3.

[0066] Glass transition temperature Tg: measured using a dynamic mechanical analyzer (DMA).

[0067] Bending resistance at low temperatures: Using a cold resistance testing machine, a test piece with a width of 5cm and a length of 14.5cm was repeatedly bent at a certain angle a certain number of times in an environment of -20℃, and the damage to the test piece was observed.

[0068] Plasticizer retention performance (expressed as migration rate): Test specimens were placed in a 120℃ oven for 7 days. The mass difference before and after baking was analyzed, and the migration rate was calculated using the following formula; in the formula, ΔW represents the mass change of the test specimen before and after baking (mg); A represents the area of ​​the test specimen placed in the test tray (dm²). 2 ); t represents the test time (number of days).

[0069]

[0070] Table 1

[0071]

[0072] Table 2

[0073]

[0074]

[0075] Table 3

[0076]

[0077]

[0078] Comparing Examples 1-3 with the Comparative Examples, it can be seen that the polyester plasticizer of the present invention contains sebacic acid residues and diethylene glycol residues linked to sebacic acid residues in its molecular backbone, as well as diol residues having silicon-oxygen structural units, straight-chain structures, or branched-chain structures, which can improve the low-temperature resistance and flexural resistance of plasticized products and reduce oil exudation.

[0079] Comparing Examples 1 with Examples 2 and 3, it can be seen that the polyester plasticizer obtained by combining diethylene glycol with a diol having a silicon-oxygen structural unit and performing an esterification reaction with sebacic acid has better low-temperature flexural resistance and plasticizer performance retention than that obtained by combining diethylene glycol with a diol having a straight-chain or branched-chain structure and performing an esterification reaction with sebacic acid.

[0080] Comparing Examples 4 and 5 with Examples 1-3, it is evident that the polyester plasticizer obtained by using sebacic acid and diethylene glycol, along with diols having silicon-oxygen structural units, linear structures, or branched chain structures, in a esterification reaction exhibits significantly improved low-temperature flexural resistance. Furthermore, comparing Example 7 with Examples 1-3, it is clear that, compared to using diethylene glycol alone, the plasticizer obtained by using a combination of diethylene glycol and diols having silicon-oxygen structural units, linear structures, or branched chain structures as the diol component exhibits significantly improved low-temperature flexural resistance.

[0081] Comparing Examples 6 and 7, it can be seen that, compared to using alcohol-based end-capping agents to end-cap the products of the esterification reaction, using acid-based end-capping agents to end-cap the products of the esterification reaction results in improved low-temperature flexural strength and improved plasticizer performance.

[0082] Beneficial effects of the embodiments

[0083] The polyester plasticizer with high cold resistance provided by this invention contains sebacic acid residues and diethylene glycol residues linked to sebacic acid residues in its molecular backbone, as well as diol residues with silicon-oxygen structural units (e.g., silicon-oxygen bonds or silicon-oxygen chains), or diol residues with straight-chain structures (e.g., dodecanediol residues), or diol residues with branched-chain structures (e.g., 2-butyl-2-ethyl-1,3-propanediol residues). Therefore, it has excellent cold resistance and migration resistance, and can be applied to PVC flexible products to improve their low-temperature resistance, flexural strength, and oil exudation.

[0084] The content disclosed above is only a preferred and feasible embodiment of the present invention, and is not intended to limit the scope of protection of the claims of the present invention. Therefore, all equivalent technical changes made based on the content of the present invention specification and drawings are included within the scope of protection of the claims of the present invention.

Claims

1. A polyester plasticizer having high cold resistance, characterized by comprising: The polyester plasticizer is obtained by esterification reaction of diacid and diol components and end-capping with an end-capping agent. The diacid component is sebacic acid, and the diol component includes a first diol component and a second diol component. The first diol component is diethylene glycol, and the second diol component is a diol with a silicon-oxygen structural unit, a diol with a straight-chain structure, or a diol with a branched-chain structure.

2. The polyester plasticizer having high cold resistance according to claim 1, characterized by, It has the structure shown in Equation I: In Formula I, A represents a residue of sebacic acid; B1 and B2 each independently represent residues of the first diol component or the second diol component; n is a positive integer from 1 to 4.

3. The polyester plasticizer having high cold resistance according to claim 2, characterized by, The diol having silicon-oxygen structural units has the structure shown in Formula II: In Formula II, Me represents methyl; in addition, the diol with a straight chain structure is dodecanediol, and the diol with a branched chain structure is 2-butyl-2-ethyl-1,3-propanediol; n is a positive integer from 1 to 12.

4. The polyester plasticizer having high cold resistance according to claim 3, characterized by, The second diol component is a diol having a silicon-oxygen structural unit; and in Formula I, B1 and B2 each independently represent residues of diethylene glycol or residues derived from the diol having a silicon-oxygen structural unit.

5. The polyester plasticizer having high cold resistance according to claim 3, characterized by, The second diol component is a diol with a straight-chain structure; and in Formula I, B1 and B2 each independently represent residues of diethylene glycol or residues derived from the diol with a straight-chain structure.

6. The polyester plasticizer with high cold resistance according to claim 3, characterized in that, The second diol component is a diol with a branched chain structure; and in Formula I, B1 and B2 each independently represent residues of diethylene glycol or residues derived from the diol with the branched chain structure.

7. The polyester plasticizer with high cold resistance according to any one of claims 4 to 6, characterized in that, The capping agent is an acid-based capping agent or an alcohol-based capping agent.

8. The polyester plasticizer with high cold resistance according to claim 7, characterized in that, The capping agent is lauric acid.

9. A polyvinyl chloride composition for making flexible articles, characterized in that, The polyvinyl chloride composition comprises 100 parts by weight of polyvinyl chloride component, plasticizer component, stabilizer and at least one inorganic additive, wherein the plasticizer component comprises the polyester plasticizer with high cold resistance according to claim 1.

10. The polyvinyl chloride composition according to claim 9, characterized in that, The plasticizer component further includes C9-C11 phthalate, and the ratio of the C9-C11 phthalate to the polyester plasticizer with high cold resistance is 3:1.

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