PHA water-based paint, and preparation method therefor and use thereof

Abstract

A PHA water-based paint, and a preparation method therefor and the use thereof. The PHA water-based paint comprises the following raw materials: a PHA water-based dispersion liquid, an emulsifier, a thickening agent, a film-forming auxiliary agent and a leveling agent, wherein the PHA water-based dispersion liquid is obtained by wall-breaking treatment of a PHA fermentation liquid. The PHA water-based dispersion liquid obtained by means of fermentation and wall breaking treatment is used for directly preparing the PHA water-based paint, and the PHA water-based paint which is not easy to settle, good in terms of storage stability, uniform in terms of dispersion and small in terms of particle size can be prepared.

Description

A PHA water-based coating and its preparation method and application

[0001] Cross-references

[0002] This application claims priority to Chinese Patent Application No. 2023112859956, filed on October 7, 2023, entitled “A PHA Water-Based Coating, Preparation Method and Application Thereof,” the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to the technical field of water-based coatings, and in particular to a PHA water-based coating and a preparation method and application thereof. Background Art

[0004] At present, water-based coatings include water-soluble coatings, water-dilutable coatings, latex coatings, etc. The preparation method of polyhydroxyalkanoate (PHA) water-based coatings is generally to add PHA powder into water and disperse it at high speed, and then add various additives and stir evenly.

[0005] Due to the agglomeration of PHA powder, a large amount of dispersants, wetting agents and other additives need to be added during the coating production process, and it is difficult to completely disperse it to the original particle size. The PHA water-based coating prepared by this method has the problems of easy sedimentation and poor storage stability.

[0006] Therefore, there is an urgent need in the art to provide a PHA water-based coating that is not easy to settle and is storage-stable, and a preparation method thereof.

[0007] Summary of the Invention

[0008] To address the above technical problems, the present invention provides a PHA water-based coating, a preparation method, and applications thereof. The present invention directly prepares the PHA water-based coating using an aqueous PHA dispersion obtained through upstream fermentation and cell wall-breaking treatment. This coating is characterized by being non-settling, excellent storage stability, uniform dispersion, and small particle size.

[0009] In a first aspect, the present invention provides a PHA water-based coating comprising: a PHA aqueous dispersion, an emulsifier, a thickener, a film-forming aid, and a leveling agent; wherein the PHA aqueous dispersion is obtained by cell wall-breaking a PHA fermentation broth.

[0010] The present invention adopts the PHA aqueous dispersion obtained by fermentation and cell wall breaking treatment upstream, and sequentially adds emulsifiers, thickeners, film-forming aids and other additives to prepare a PHA water-based coating that is not easy to settle, has good storage stability, is evenly dispersed and has a small particle size.

[0011] Preferably, the PHA aqueous dispersion is selected from one or more of a PHB aqueous dispersion, a P34HB aqueous dispersion, a PHBV aqueous dispersion, a PHBHHx aqueous dispersion and a P3HB4HB3HV aqueous dispersion.

[0012] More preferably, the 4HB monomer content in the P34HB is 5% to 20%, which can be any value between 5% and 20%, such as 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, and 20%; the HV monomer content in the PHBV is 5% to 15%, which can be any value between 5% and 15%, such as 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, and 15%; the HHx monomer content in the PHBHHx is 5% to 15%. %, can be any value between 5% and 15%, for example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, and 15%; the 4HB monomer content in the P3HB4HB3HV is 21% to 30%, for example, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, and 30%, and the 3HV monomer content is 5% to 20%, for example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, and 20%. Unless otherwise specified in the present invention, monomer content is molar content.

[0013] Further preferably, the PHA aqueous dispersion is selected from one or more of a PHB aqueous dispersion, a P34HB aqueous dispersion having a 4HB monomer content of 10%, a PHBV aqueous dispersion having an HV monomer content of 10%, a PHBHHx aqueous dispersion having an HHx monomer content of 10%, and a P3HB4HB3HV aqueous dispersion having a 4HB monomer content of 22% and a 3HV monomer content of 10%.

[0014] More preferably, in the aqueous PHA dispersion, the PHA particle size D50 is ≤ 1 μm, preferably 0.1-1 μm.

[0015] In the present invention, there is no limitation on the content of PHA in the aqueous PHA dispersion. For example, in some embodiments of the present invention, the content of PHA is 20%-50%.

[0016] Preferably, the emulsifier is sodium dodecyl sulfate and / or sodium dodecylbenzene sulfonate.

[0017] Preferably, the thickener is selected from one or more of nanocellulose, sodium hydroxypropyl cellulose, sodium alginate, gelatinized starch, polyacrylonitrile, sodium polyacrylate, sodium alginate, and polypyrrolidone.

[0018] Preferably, the film-forming aid is selected from one or more of diethanol ether, propylene glycol ether, and N-methylpyrrolidone.

[0019] Preferably, the leveling agent is selected from one or more of polyether siloxane copolymers, modified polysiloxanes, and cellulose.

[0020] Preferably, the PHA water-based coating comprises the following raw materials in parts by mass: 20-50 parts of PHA in a PHA aqueous dispersion, 0.01-0.5 parts of an emulsifier, 0.01-0.5 parts of a thickener, 0.01-0.5 parts of a film-forming aid, and 0.01-0.5 parts of a leveling agent.

[0021] More preferably, the PHA aqueous dispersion contains 20-30 parts of PHA, 0.05-0.2 parts of emulsifier, 0.05-0.3 parts of thickener, 0.05-0.3 parts of film-forming aid, and 0.01-0.1 parts of leveling agent.

[0022] In a second aspect, the present invention provides a method for preparing the PHA water-based coating, comprising the steps of mixing the PHA aqueous dispersion, an emulsifier, a thickener, a film-forming aid, and a leveling agent according to a mass ratio, stirring, and removing bubbles.

[0023] Preferably, the viscosity of the prepared PHA water-based coating is controlled to be 300-400 mPa.s, and the PHA particle size D50 is controlled to be 0.1-1 μm.

[0024] In the present invention, by controlling the parameter conditions of the prepared PHA water-based coating, when the PHA water-based coating is directly prepared from the PHA aqueous dispersion, the emulsifier, thickener, film-forming aid and leveling agent can interact better, thereby improving the dispersion performance and having better stability.

[0025] Preferably, the stirring can be performed by using a commonly used dispersion method in the art, such as mechanical stirring or ultrasonic dispersion.

[0026] Further preferably, the stirring includes mechanical stirring for 30-60 min, followed by ultrasonic treatment for 20-30 min; preferably, in a specific embodiment of the present invention, when mechanical stirring is used, the rotation speed is controlled at 2000 rpm; when ultrasonic dispersion is used, the dispersion time is controlled at 30 min.

[0027] In a third aspect, the present invention provides an application of the PHA water-based coating or the PHA water-based coating obtained by the preparation method of the PHA water-based coating, comprising applying the PHA water-based coating to a substrate surface and then performing a drying treatment.

[0028] More preferably, the drying temperature is 110-150° C., and the drying time is 10-30 seconds.

[0029] In the present invention, the substrate can be made of paper, plastic, wood, metal or the like, and the coating can be performed by scraper coating, gravure printing or the like.

[0030] More preferably, the processing temperature of the paper is 150° C. or lower.

[0031] It should be noted that the processing temperature tolerance refers to the temperature at which the paper can be processed without deformation or yellowing due to heat, which would otherwise affect its appearance and performance. The paper used in the present invention includes conventional paper with a processing temperature tolerance between the melting point of PHA and 150°C, such as white cardboard, gray board, coated paper, offset paper, corrugated paper, writing paper, kraft paper, and newsprint. It does not include specialty paper with a processing temperature tolerance exceeding 150°C. In the specific embodiments of the present invention, the paper used is white cardboard.

[0032] The present invention has at least the following beneficial effects: The present invention uses a PHA aqueous dispersion obtained through fermentation and cell wall fragmentation to directly prepare a PHA water-based coating. The PHA particles are small, and the resulting PHA water-based coating is less susceptible to sedimentation and exhibits excellent storage stability. The PHA aqueous dispersion of the present invention achieves excellent stability, prevents stratification at rest, and reduces material costs, without requiring the use of large amounts of dispersants, wetting agents, and other additives. The present invention has a simple production process and broad application prospects. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0034] If specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this field or in the product instructions were used. The experimental methods used in the following examples are all conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified. The instruments used, etc., for which the manufacturer is not specified, are all conventional products that can be purchased through regular channels.

[0035] The term "comprising" or "including" in the present invention is an open description, containing the specified components or steps described, as well as other specified components or steps that will not be substantially affected. The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in this article.

[0036] In the description of this specification, the reference terms "one embodiment", "some embodiments", "specific implementation methods", or "some specific implementation methods" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, unless they are mutually inconsistent.

[0037] In the present invention, PHA is the abbreviation of polyhydroxyalkanoate, PHB is the abbreviation of poly 3-hydroxybutyrate, P34HB is the abbreviation of copolyester of 3-hydroxybutyric acid and 4-hydroxybutyric acid, PHBV is the abbreviation of copolyester of 3-hydroxybutyric acid and 3-hydroxyvaleric acid, PHBHHx is the abbreviation of copolyester of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid, and P3HB4HB3HV is the abbreviation of tripolyester of 3-hydroxybutyric acid, 4-hydroxybutyric acid and 3-hydroxyvaleric acid.

[0038] In the embodiments of the present invention, the PHB aqueous dispersion, the P34HB aqueous dispersion with a 4HB monomer content of 10%, the PHBV aqueous dispersion with a HV monomer content of 10%, the PHBHHx aqueous dispersion with a HHx monomer content of 10%, and the P3HB4HB3HV aqueous dispersion with a 4HB monomer content of 22% and a 3HV monomer content of 10% are all obtained by cell wall breaking treatment of PHA fermentation broth, and are products of Beijing Microstructure Factory Biotechnology Co., Ltd.

[0039] In the embodiment of the present invention, the reslurryability test method is as follows: the test is performed according to the standard T_ZZB 2836-2022 for water-based coated paperboard for food packaging.

[0040] The static stability test method is: place the aqueous emulsion in a room temperature environment, let it stand for 24 hours, and observe whether stratification occurs. If stratification occurs, it is judged as unqualified.

[0041] The corn oil resistance test method involves adding a certain amount of corn oil at a specified temperature (23°C or 100°C) to a heat-sealed paper cup, filling it to approximately 6mm from the cup's rim. The cup is then placed on a flat glass plate and left to stand for 1 hour before being inspected for signs of leakage. Five cups are tested for each sample; if even one shows leakage, the cup is deemed unqualified.

[0042] The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0043] Example 1

[0044] This embodiment provides a PHA water-based coating and a preparation method thereof. The PHA water-based coating uses the following raw materials in parts by weight:

[0045] The PHB aqueous dispersion contains 25 parts of PHB, 0.1 parts of sodium lauryl sulfate, 0.2 parts of sodium hydroxypropyl cellulose, 0.1 parts of diethanol ether, and 0.01 parts of polyether siloxane copolymer.

[0046] Preparation steps of water-based paint: weigh each component according to the mass ratio, viscosity 350mPa.s, PHA particle size D50 0.7um, mechanical stirring for 30min, and ultrasonication for 20min to remove bubbles.

[0047] The prepared PHA water-based coating was applied to the paper surface using a scraper coating method, and then dried at a temperature of 150° C. for 10 s.

[0048] Storage stability: The water-based paint was placed at 50°C for 5 days with slight stratification, which did not affect its use.

[0049] Example 2

[0050] This embodiment provides a PHA water-based coating and a preparation method thereof. The PHA water-based coating uses the following raw materials in parts by weight:

[0051] The P34HB aqueous dispersion (4HB monomer content 10%) contains 25 parts of P34HB, 0.1 parts of sodium dodecylbenzenesulfonate, 0.2 parts of sodium alginate, 0.1 parts of propylene glycol ether, and 0.01 parts of modified polysiloxane.

[0052] Preparation steps of water-based paint: weigh each component according to the mass ratio and mix them, viscosity 380mPa.s, PHA particle size D50 0.8um, mechanical stirring for 30min, and ultrasonication for 20min to remove bubbles.

[0053] The prepared PHA water-based coating was applied to the paper surface using a scraper coating method, and then dried at a drying temperature of 120° C. for 25 s.

[0054] Storage stability: The water-based paint was placed at 50°C for 5 days with slight stratification, which did not affect its use.

[0055] Example 3

[0056] This embodiment provides a PHA water-based coating and a preparation method thereof. The PHA water-based coating uses the following raw materials in parts by weight:

[0057] The PHBV aqueous dispersion (HV monomer content 10%) contains 25 parts of PHBV, 0.1 parts of sodium dodecylbenzenesulfonate, 0.2 parts of polyacrylonitrile, 0.1 parts of N-methylpyrrolidone, and 0.01 parts of cellulose.

[0058] Preparation steps of water-based paint: weigh each component according to the mass ratio, viscosity 320mPa.s, PHA particle size D50 0.1um, mechanical stirring for 30min, and ultrasonication for 20min to remove bubbles.

[0059] The prepared PHA water-based coating was applied to the paper surface using a scraper coating method, and then dried at a temperature of 130° C. for 20 seconds.

[0060] Storage stability: The water-based paint was placed at 50°C for 5 days with slight stratification, which did not affect its use.

[0061] Example 4

[0062] This embodiment provides a PHA water-based coating and a preparation method thereof. The PHA water-based coating uses the following raw materials in parts by weight:

[0063] The PHBHHx aqueous dispersion (HHx monomer content 10%) contains 25 parts of PHBHHx, 0.1 parts of sodium lauryl sulfate, 0.2 parts of polypyrrolidone, 0.1 parts of diethanol ether, and 0.01 parts of cellulose.

[0064] Preparation steps of water-based paint: weigh each component according to the mass ratio, viscosity 320mPa.s, PHA particle size D50 0.5um, mechanical stirring for 30min, and ultrasonication for 20min to remove bubbles.

[0065] The prepared PHA water-based coating was applied to the paper surface using a scraper coating method, and then dried at a temperature of 130° C. for 20 seconds.

[0066] Storage stability: The water-based paint was placed at 50°C for 5 days with slight stratification, which did not affect its use.

[0067] Example 5

[0068] This embodiment provides a PHA water-based coating and a preparation method thereof. The PHA water-based coating uses the following raw materials in parts by weight:

[0069] The P3HB4HB3HV aqueous dispersion (4HB monomer content 22%, 3HV monomer content 10%) contains 25 parts of P3HB4HB3HV, 0.1 parts of sodium dodecylbenzenesulfonate, 0.2 parts of sodium hydroxypropyl cellulose, 0.1 parts of propylene glycol ether, and 0.01 parts of modified polysiloxane.

[0070] Preparation steps of water-based paint: weigh each component according to the mass ratio, viscosity 390mPa.s, PHA particle size D50 0.7um, mechanical stirring for 30min, and ultrasonication for 20min to remove bubbles.

[0071] The prepared PHA water-based coating was applied to the paper surface using a scraper coating method, and then dried at a drying temperature of 110° C. for 30 seconds.

[0072] Storage stability: The water-based paint was placed at 50°C for 5 days with slight stratification, which did not affect its use.

[0073] Example 6

[0074] This embodiment provides a PHA water-based coating and a preparation method thereof. The PHA water-based coating uses the following raw materials in parts by weight:

[0075] The P3HB4HB3HV aqueous dispersion (4HB monomer content 22%, 3HV monomer content 10%) contains 28 parts of P3HB4HB3HV, 0.1 parts of sodium dodecylbenzenesulfonate, 0.2 parts of sodium hydroxypropyl cellulose, 0.1 parts of propylene glycol ether, and 0.01 parts of modified polysiloxane.

[0076] Preparation steps of water-based paint: weigh each component according to the mass ratio, viscosity 390mPa.s, PHA particle size D50 0.7um, mechanical stirring for 30min, and ultrasonication for 20min to remove bubbles.

[0077] The prepared PHA water-based coating was applied to the paper surface using a scraper coating method, and then dried at a drying temperature of 110° C. for 30 seconds.

[0078] Storage stability: The water-based paint was placed at 50°C for 5 days with slight stratification, which did not affect its use.

[0079] Comparative Example 1

[0080] This comparative example provides a PHA water-based coating and a preparation method thereof. The PHA water-based coating uses the following raw materials in parts by weight:

[0081] P34HB powder (4HB monomer content 10%) contains 25 parts of P34HB, 75 parts of water, 0.1 parts of sodium dodecylbenzene sulfonate, 0.2 parts of sodium hydroxypropyl cellulose, 0.1 parts of propylene glycol ether, 0.01 parts of modified polysiloxane, 0.2 parts of dispersant Dow 731A, and 0.1 parts of wetting agent Maier Chemical HY352.

[0082] Preparation steps of water-based paint: weigh each component according to the mass ratio, viscosity 320mPa.s, PHA particle size D50 5um, mechanical stirring for 30min, and ultrasonication for 20min to remove bubbles.

[0083] The prepared PHA water-based coating was applied to the paper surface using a scraper coating method, and then dried at a drying temperature of 110° C. for 30 seconds.

[0084] Storage stability: The water-based paint was left at 50°C for 5 days and showed severe stratification and could not be used.

[0085] Comparative Example 2

[0086] This comparative example provides a PHA water-based coating and a preparation method thereof. The PHA water-based coating uses the following raw materials in parts by weight:

[0087] P34HB powder (4HB monomer content 10%) contains 25 parts of P34HB, 75 parts of water, 0.1 parts of sodium dodecylbenzenesulfonate, 0.2 parts of sodium hydroxypropylcellulose, 0.1 parts of propylene glycol ether, and 0.01 parts of modified polysiloxane.

[0088] Preparation steps of water-based paint: weigh each component according to the mass ratio, viscosity 390mPa.s, PHA particle size D50 0.7um, mechanical stirring for 30min, and ultrasonication for 20min to remove bubbles.

[0089] The prepared PHA water-based coating was applied to the paper surface using a scraper coating method, and then dried at a drying temperature of 110° C. for 30 seconds.

[0090] Storage stability: The water-based paint was left at 50°C for 5 days and showed severe stratification and could not be used.

[0091] Table 1 Test results of examples and comparative examples

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention. Industrial Applicability

[0093] The present invention provides a PHA water-based coating, a preparation method, and applications thereof. The PHA water-based coating comprises the following raw materials: a PHA aqueous dispersion, an emulsifier, a thickener, a film-forming aid, and a leveling agent; the PHA aqueous dispersion is obtained by cell-breaking a PHA fermentation broth. The present invention directly prepares the PHA water-based coating using an upstream PHA aqueous dispersion obtained through fermentation and cell-breaking. This coating is capable of producing a PHA water-based coating that is non-settling, exhibits excellent storage stability, is uniformly dispersed, and has a small particle size. The coating has good economic value and application prospects.

Claims

1. A PHA water-based coating, characterized in that: include: PHA aqueous dispersion, emulsifier, thickener, film-forming aid and leveling agent; wherein the PHA aqueous dispersion is obtained by cell-breaking treatment of PHA fermentation broth.

2. The PHA water-based coating according to claim 1, characterized in that: The PHA aqueous dispersion is selected from one or more of a PHB aqueous dispersion, a P34HB aqueous dispersion, a PHBV aqueous dispersion, a PHBHHx aqueous dispersion and a P3HB4HB3HV aqueous dispersion.

3. The PHA water-based coating according to claim 1 or 2, characterized in that: In the PHA aqueous dispersion, the PHA particle size D50 is ≤1 μm, preferably 0.1-1 μm.

4. The PHA water-based coating according to any one of claims 1 to 3, characterized in that: The emulsifier is sodium dodecyl sulfate and / or sodium dodecylbenzene sulfonate; and / or the thickener is selected from one or more of nanocellulose, sodium hydroxypropyl cellulose, sodium alginate, gelatinized starch, polyacrylonitrile, sodium polyacrylate, sodium alginate, and polypyrrolidone.

5. The PHA water-based coating according to any one of claims 1 to 3, characterized in that: The film-forming aid is selected from one or more of diethanol ether, propylene glycol ether and N-methyl pyrrolidone.

6. The PHA water-based coating according to any one of claims 1 to 3, characterized in that: The leveling agent is selected from one or more of polyether siloxane copolymer, modified polysiloxane and cellulose.

7. The PHA water-based coating according to any one of claims 1 to 3, characterized in that: The method comprises the following raw materials in parts by weight: 20-50 parts of PHA in a PHA aqueous dispersion, 0.01-0.5 parts of an emulsifier, 0.01-0.5 parts of a thickener, 0.01-0.5 parts of a film-forming aid, and 0.01-0.5 parts of a leveling agent; Preferably, the PHA aqueous dispersion contains 20-30 parts of PHA, 0.05-0.2 parts of emulsifier, 0.05-0.3 parts of thickener, 0.05-0.3 parts of film-forming aid, and 0.01-0.1 parts of leveling agent.

8. The method for preparing the PHA water-based coating according to any one of claims 1 to 7, characterized in that: The method comprises the steps of mixing the PHA aqueous dispersion, emulsifier, thickener, film-forming aid and leveling agent according to mass ratio, stirring and removing bubbles.

9. The method for preparing the PHA water-based coating according to claim 8, characterized in that: The viscosity of the prepared PHA water-based coating is controlled to be 300-400 mPa.s, and the PHA particle size D50 is controlled to be 0.1-1 um; and / or, the stirring includes mechanical stirring for 30-60 minutes, and then ultrasonic treatment for 20-30 minutes.

10. Use of the PHA water-based coating according to any one of claims 1 to 7 or the PHA water-based coating prepared by the method of preparing the PHA water-based coating according to claim 8 or 9, characterized in that: The process comprises applying the PHA water-based coating to the surface of the substrate and then performing a drying treatment; preferably, the drying temperature is 110-150° C. and the drying time is 10-30 seconds.

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