CN111518319B - Starch-based plastic and preparation method thereof - Google Patents
Starch-based plastic and preparation method thereof Download PDFInfo
- Publication number
- CN111518319B CN111518319B CN202010481310.5A CN202010481310A CN111518319B CN 111518319 B CN111518319 B CN 111518319B CN 202010481310 A CN202010481310 A CN 202010481310A CN 111518319 B CN111518319 B CN 111518319B
- Authority
- CN
- China
- Prior art keywords
- starch
- parts
- plasticizer
- cold water
- pregelatinized
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L3/00—Compositions of starch, amylose or amylopectin or of their derivatives or degradation products
- C08L3/04—Starch derivatives, e.g. crosslinked derivatives
- C08L3/08—Ethers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2201/00—Properties
- C08L2201/06—Biodegradable
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
- C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Processes Of Treating Macromolecular Substances (AREA)
Abstract
The invention belongs to the technical field of high polymer materials, and particularly relates to a starch-based plastic and a preparation method thereof, wherein the starch-based plastic comprises the following components in parts by weight: 45-70 parts of partially pregelatinized hydroxypropyl starch, 1-30 parts of bio-based resin, 0-5 parts of plasticizer, 1-5 parts of compatilizer and 1-5 parts of lubricant. The starch-based plastic is prepared by replacing natural starch with partial pregelatinized starch with specific cold water solubility, has higher tensile strength, toughness and processability, contains less plasticizer or even no plasticizer compared with the traditional formula, solves the problem of plasticizer migration, and can be applied to preparation of safe food packaging materials.
Description
Technical Field
The invention belongs to the technical field of high polymer materials. More particularly, it relates to a starch-based plastic and a method for preparing the same.
Background
Starch-based biodegradable plastic is one of the most promising degradable plastics at present, and is generally prepared by blending Starch (TPS), plasticizer and degradable resin, such as polylactic acid, polycaprolactone, polybutylene succinate and the like, and has better processing performance and cost advantage compared with pure degradable resin. The natural starch contains a large amount of hydroxyl groups, has strong polarity and hydrophilicity, contains 13-20% of moisture, and the moisture and the hydroxyl groups in the starch can form strong hydrogen bonds, so that the natural starch presents a granular structure. In conclusion, the natural starch is a natural macromolecule with high rigidity and a plurality of medium chains, the macromolecule comprises crystalline and amorphous heterogeneous substances, and a plurality of groups which can form hydrogen bonds such as hydroxyl groups are learned in the molecule, so that the crystallinity is high, and the properties result in that the melting point of the starch is higher than the degradation temperature of the starch, and the starch cannot be directly processed in practice. In order to improve the fluidity of starch, a plasticizer is required to be added, so that the plasticity of the starch is improved, the hydrogen bonding action of the plasticized starch molecules is weakened, the diffusion capacity of molecular chains is improved, the glass transition temperature of the material is reduced, and the melting of microcrystals can be realized before the starch is decomposed. Meanwhile, the film prepared from the original starch has poor mechanical property and larger brittleness, and the plasticizer is added to increase the distance between starch molecules and improve the flexibility of a molecular chain, so that the toughness of the starch film is improved.
However, like the traditional polymer materials, the starch-based plastics are easy to migrate from the interior of the materials to the packaging interface, and the health hazard caused by the migration of the plasticizer has attracted attention of the masses. At present, in order to inhibit the migration of the plasticizer, related researchers have studied to modify the high molecular polymer by different means, for example, modifying the surface of the material by using a radiation technology; adding nano particles which have stronger interaction with the plasticizer and the material, and the like. However, the above-mentioned technical means are all to suppress the migration of the plasticizer by modifying the material or the like.
Pregelatinized starch refers to modified starch prepared by partially or totally breaking down starch granules by chemical or mechanical means, which is insoluble in organic solvents, slightly soluble to be soluble in cold water, and has better fluidity and mechanical strength than native starch. At present, pregelatinized starch is mainly used as a pharmaceutical adjuvant such as an adhesive, a diluent, a disintegrant and the like, and no report of preparing degradable plastics by using the pregelatinized starch as a plastic main body instead of starch is found.
Disclosure of Invention
The invention aims to overcome the defects of the existing starch-based material and provide a starch-based material without a plasticizer, wherein the material is compounded with a bio-based resin by adopting partially pregelatinized hydroxypropyl starch instead of raw starch, so that a degradable material with good mechanical property and processability and without the problem of plasticizer migration is obtained, and the degradable material has a wide prospect when being applied to food packaging.
Therefore, the invention specifically adopts the technical scheme that: the starch-based plastic comprises the following components in parts by weight: 45-70 parts of partially pregelatinized hydroxypropyl starch, 1-30 parts of bio-based resin, 0-5 parts of plasticizer, 1-5 parts of compatilizer and 1-5 parts of lubricant.
The pregelatinized hydroxypropyl starch can be prepared by adopting any one of corn starch, pea starch, rice starch, wheat starch and sweet potato starch as a raw material, and preferably adopts the corn starch as the raw starch. The pregelatinized hydroxypropyl starch can be prepared by chemical or mechanical activation, preferably mechanical activation. In the mechanical force activation process of the starch, due to the action of mechanical forces such as friction, impact, collision, shearing and the like, the shape, granularity and surface properties of natural starch particles can be changed, the crystalline structure of the starch is damaged, the crystallinity is reduced, the polycrystalline state is changed into an amorphous state, and meanwhile, the arrangement of molecular chains of the starch, the molecular weight distribution and the proportion of direct connection and branched chain content can be changed. Therefore, the pregelatinized hydroxypropyl starch obtained by mechanical activation has higher mechanical strength and fluidity and better processability than the original starch.
Further, the partially pregelatinized hydroxypropyl starch has a cold water solubility of 10-45%. Still further, the partially pregelatinized hydroxypropyl starch consists of two partially pregelatinized hydroxypropyl starches having different cold water solubilities.
Further, the partially pregelatinized hydroxypropyl starch is composed of pregelatinized hydroxypropyl starch having cold water solubility of 10-25% and pregelatinized hydroxypropyl starch having cold water solubility of 30-42%.
Further, the weight ratio of the pregelatinized hydroxypropyl starch with the cold water solubility of 10-25% to the pregelatinized hydroxypropyl starch with the cold water solubility of 30-42% is 3: 1-2.
Further, the partially pregelatinized hydroxypropyl starch consists of pregelatinized hydroxypropyl starch having a cold water solubility of 25.0% and pregelatinized hydroxypropyl starch having a cold water solubility of 35.7% in a weight ratio of 3: 2.
As used herein, "cold water solubility" refers to any amount of solubility in water at room temperature (25. + -. 1-2 ℃ C.).
The method for measuring the cold water solubility comprises the following steps: a pregelatinized starch sample 2.0g (W) was added to 100mL of deionized water at a constant temperature (25. + -. 1-2 ℃), continuously stirred, stirred at a high speed for 2min, placed in a centrifuge tube, centrifuged at 3000rpm for 20min, 25mL of the supernatant was removed by a pipette, dried at 110 ℃ to constant weight to obtain the weight (T, g) of the dissolved starch, and the cold water solubility (Sc,%) was calculated according to the following formula.
The cold water solubility of the pregelatinized hydroxypropyl starch is continuously increased along with the increase of the activation time, and the pregelatinized hydroxypropyl starch with different cold water solubilities can be accurately prepared by controlling the time and the temperature of mechanical force activation. The mechanical force activation time is controlled to be 10-40 min, and the temperature is controlled to be 50 ℃, so that the pregelatinized hydroxypropyl starch with the cold water solubility of 10-45% can be prepared.
The inventors have surprisingly found that pregelatinized starch comprising a particular cold water solubility and particle size can bring the following significant benefits to the material, for example: firstly, the tensile strength of the material is obviously improved; compared with hydroxypropyl starch, the mechanical strength and the fluidity of the hydroxypropyl starch are obviously improved after the hydroxypropyl starch is pregelatinized, and pregelatinized hydroxypropyl starch molecules and the bio-based resin can be better combined, so that the mechanical property of a material system is better enhanced; ③ systems containing two pregelatinized hydroxypropyl starches with different cold water solubilities can contain smaller amounts of plasticizer, even without plasticizer, still show good processability and mechanical properties. Whereas if pregelatinized starch with a cold water solubility of < 10% or > 45% is added, the same benefits are not imparted to the material.
Further, the plasticizer is selected from one of glycerin, urea, and formamide. In the material system according to the invention, preference is given to using glycerol as plasticizer, which may be present in the form of 2 parts by weight or in smaller amounts.
Further, the bio-based resin is selected from one of polyvinyl alcohol, polylactic acid, polycaprolactone, polybutylene succinate and polyhydroxyalkanoate. Still further, the bio-based resin is selected from polylactic acid.
Further, the compatibilizer is selected from white oil and/or mineral oil; the lubricant is at least one selected from liquid paraffin, stearic acid amide and n-butyl stearate.
One embodiment of the invention provides a starch-based plastic, which comprises the following components in parts by weight: 45-70 parts of partially pregelatinized hydroxypropyl starch, 1-30 parts of polylactic acid, 0-5 parts of glycerol, 1-5 parts of a compatilizer and 1-5 parts of stearic acid; wherein the partial pregelatinized hydroxypropyl starch consists of pregelatinized hydroxypropyl starch with cold water solubility of 10-25% and pregelatinized hydroxypropyl starch with cold water solubility of 30-42% in a weight ratio of 3: 1-2; wherein the partially pregelatinized hydroxypropyl starch consists of pregelatinized hydroxypropyl starch with cold water solubility of 10-25% and pregelatinized hydroxypropyl starch with cold water solubility of 30-42%.
Another object of the present invention is to provide a method for preparing said starch-based plastic, comprising the steps of:
drying the raw materials at 60-80 ℃ for 6-10 h, adding part of pregelatinized hydroxypropyl starch and a plasticizer into a high-speed mixer, uniformly mixing, adding the bio-based resin, the compatilizer and the lubricant, uniformly mixing, and extruding and granulating by a double-screw extruder.
The invention has the following beneficial effects:
the starch-based plastic is prepared by replacing natural starch with partial pregelatinized starch with specific cold water solubility, has more excellent mechanical property, contains less plasticizer or even no plasticizer compared with the traditional formula, avoids the problem of plasticizer migration, and can be applied to preparation of safe food packaging materials.
Detailed Description
The present invention is further illustrated by the following specific examples, which are not intended to limit the invention in any way. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.
Unless otherwise indicated, reagents and materials used in the following examples are commercially available.
Example 1 preparation of partially pregelatinized hydroxypropyl starches of different cold water solubility
The method comprises the following specific steps: and (2) adopting a ball mill, adopting bearing steel balls as grinding balls, cooling the grinding balls by using circulating water during ball milling at the rotating speed of 300r/min, wherein the mass ratio of ball materials is 20:3, and other ball milling process parameters are shown in the following table 1, taking out the materials after ball milling, and sieving to obtain 1# to 9# partially pregelatinized hydroxypropyl starch.
TABLE 1 mechanical force activation parameters
| Numbering | Raw materials | Time of activation | Activation temperature | Cold water solubility |
| 1# | Hydroxypropyl corn starch | 3min | 50℃ | 5.0％ |
| 2# | Hydroxypropyl corn starch | 10min | 50℃ | 15.2％ |
| 3# | Hydroxypropyl corn starch | 17min | 50℃ | 20.2％ |
| 4# | Hydroxypropyl corn starch | 22min | 50℃ | 25.0％ |
| 5# | Hydroxypropyl corn starch | 28min | 50℃ | 31.5％ |
| 6# | Hydroxypropyl corn starch | 35min | 50℃ | 35.7％ |
| 7# | Hydroxypropyl corn starch | 43min | 50℃ | 42.0％ |
| 8# | Hydroxypropyl corn starch | 47min | 50℃ | 45.0％ |
| 9# | Hydroxypropyl corn starch | 51min | 50℃ | 48.3％ |
Table 2 examples 2-8 formulation and parts by weight of starch-based plastics
The preparation method comprises the following steps:
drying the raw materials at 80 ℃ for 8h, adding part of pregelatinized hydroxypropyl starch and glycerol into a high-speed mixer, and uniformly mixing; adding polylactic acid, mineral oil, white oil and stearic acid, uniformly mixing, and extruding and granulating by a double-screw extruder; the length-diameter ratio of the double-screw extruder is 45:1, and the temperatures of four sections of the double screw are as follows: the temperature of the first section is 85-90 ℃, the temperature of the second section is 107-110 ℃, the temperature of the third section is 115-118 ℃, and the temperature of the fourth section is 125-130 ℃.
Comparative example 6 compared to example 6 except that instead of pregelatinized hydroxypropyl starch, hydroxypropyl starch was replaced by hydroxypropyl starch, the remaining parameters were the same as in example 6.
Test example I, mechanical Property test
The materials prepared in examples 2-8 and comparative examples 1-6 were injection molded into standard tensile sample strips and impact sample strips, the injection molding temperature was 175-185 ℃, the injection molding pressure was 70-90 MPa, and the holding pressure was 45MPa, and the tensile strength and elongation at break were measured according to GB9341-2000 standard, and the measurement results are shown in Table 3 below.
TABLE 3 test results
From the above table, it can be seen that the inclusion of pregelatinized hydroxypropyl starch having two different cold water solubilities, combined in a specific weight ratio, provides a material system with a significant increase in tensile strength and toughness as compared to the addition of unmodified hydroxypropyl starch (comparative example 6). Of these, the best overall performance of example 6, the tensile strength and toughness of the material were increased by 88.8% and 84.2% respectively over the addition of the unmodified hydroxypropyl starch composite, while the same benefits could not be achieved if only one cold water soluble pregelatinized hydroxypropyl starch was added (comparative examples 3 and 4). While comparative example 5 contains no plasticizer, the tensile strength and toughness of the material were increased by 70.8% and 56.7%, respectively, as compared to comparative example 6, indicating that a material system incorporating pregelatinized hydroxypropyl starch with two different cold water solubilities still achieved better performance without the addition of plasticizer.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Claims (4)
1. The starch-based plastic is characterized by comprising the following components in parts by weight: 45-70 parts of partially pregelatinized hydroxypropyl starch, 1-30 parts of polylactic acid, 0-5 parts of glycerol, 1-5 parts of a compatilizer and 1-5 parts of stearic acid; the partial pregelatinized hydroxypropyl starch consists of pregelatinized hydroxypropyl starch with the cold water solubility of 10-25% and pregelatinized hydroxypropyl starch with the cold water solubility of 30-42% in a weight ratio of 3: 1-2.
2. The starch-based plastic according to claim 1, wherein the native starch of the partially pregelatinized hydroxypropyl starch is selected from the group consisting of corn starch, pea starch, rice starch, wheat starch, and sweet potato starch.
3. The starch-based plastic according to claim 1, wherein the compatibilizer is selected from white oil and/or mineral oil.
4. A method for preparing a starch-based plastic according to any one of claims 1 to 3, comprising the steps of:
drying the raw materials at 60-80 ℃ for 6-10 h, adding part of pregelatinized hydroxypropyl starch and glycerol into a high-speed mixer, uniformly mixing, adding polylactic acid, a compatilizer and stearic acid, uniformly mixing, and extruding and granulating by a double-screw extruder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010481310.5A CN111518319B (en) | 2020-05-31 | 2020-05-31 | Starch-based plastic and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010481310.5A CN111518319B (en) | 2020-05-31 | 2020-05-31 | Starch-based plastic and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111518319A CN111518319A (en) | 2020-08-11 |
| CN111518319B true CN111518319B (en) | 2021-10-29 |
Family
ID=71911550
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010481310.5A Active CN111518319B (en) | 2020-05-31 | 2020-05-31 | Starch-based plastic and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111518319B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113388043B (en) * | 2021-06-30 | 2022-06-17 | 西南林业大学 | Thermosetting starch-based plastic and preparation method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104262493A (en) * | 2014-09-05 | 2015-01-07 | 湖南尔康制药股份有限公司 | Preparation method and use of medicinal pregelatinized hydroxypropyl starch |
| CN105440606A (en) * | 2014-09-02 | 2016-03-30 | 允友成(宿迁)复合新材料有限公司 | Preparation method of fully biodegradable starch/polylactic acid base resin |
| CN106535646A (en) * | 2014-05-27 | 2017-03-22 | 泰特&莱尔组分美国公司 | Starch compositions for thickening aqueous liquids |
| CN107987618A (en) * | 2013-03-29 | 2018-05-04 | 罗盖特公司 | Film-forming composition for the coating of solid form |
-
2020
- 2020-05-31 CN CN202010481310.5A patent/CN111518319B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107987618A (en) * | 2013-03-29 | 2018-05-04 | 罗盖特公司 | Film-forming composition for the coating of solid form |
| CN106535646A (en) * | 2014-05-27 | 2017-03-22 | 泰特&莱尔组分美国公司 | Starch compositions for thickening aqueous liquids |
| CN105440606A (en) * | 2014-09-02 | 2016-03-30 | 允友成(宿迁)复合新材料有限公司 | Preparation method of fully biodegradable starch/polylactic acid base resin |
| CN104262493A (en) * | 2014-09-05 | 2015-01-07 | 湖南尔康制药股份有限公司 | Preparation method and use of medicinal pregelatinized hydroxypropyl starch |
Non-Patent Citations (1)
| Title |
|---|
| "预糊化对挤压吹塑制备淀粉/PVA纳米复合膜性能的影响";王文涛等;《中国粮油学报》;20151225;第30卷(第12期);第53-58页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111518319A (en) | 2020-08-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR102574368B1 (en) | Biodegradable polyester articles containing enzymes | |
| JP7217267B2 (en) | Liquid compositions containing biological entities and uses thereof | |
| Sabetzadeh et al. | Study on ternary low density polyethylene/linear low density polyethylene/thermoplastic starch blend films | |
| CN108929527B (en) | PBAT/modified starch full-biodegradable film with high ductility and high barrier property as well as preparation method and application thereof | |
| CN106751625B (en) | A kind of biodegradable high-barrier shape material products and preparation method thereof | |
| CN108559232A (en) | A kind of starch plastics film and preparation method thereof that tearing-resistant performance is excellent | |
| EP1860138A1 (en) | Biodegradable thermoplastic nanocomposite polymers | |
| CN112552654B (en) | PBAT/PHA/wood flour composition suitable for preparing film and preparation and application thereof | |
| CN112552655B (en) | Modified cellulose filled PBAT/PLA composition suitable for preparing film, and preparation and application thereof | |
| US11859081B2 (en) | Biobased additive for thermoplastic polyesters | |
| CN113956630A (en) | Completely biodegradable film and preparation method thereof | |
| CN111763410B (en) | Biodegradable PBAT alloy with high starch content and preparation method thereof | |
| CN111518319B (en) | Starch-based plastic and preparation method thereof | |
| US20230340212A1 (en) | Method for preparing an enzyme masterbatch | |
| US11130259B1 (en) | Device and method for online preparation of modified polylactic acid material with polylactic acid melt | |
| CN113956546A (en) | Preparation method of starch-based fully-degradable blown film composition | |
| CN111423627B (en) | Degradable plastic and preparation method thereof | |
| CN116891623A (en) | Biological full-degradable material and preparation method thereof | |
| CN111286164B (en) | Biodegradable plastic and preparation method thereof | |
| CN114276584A (en) | Starch masterbatch capable of completely biodegrading film and preparation method thereof | |
| CN103965600A (en) | Method for toughening heat-resistant modified polylactic acid with plant-base composite environment-friendly modifier | |
| CN113881111A (en) | Thermoplastic corn starch for plastic filling and preparation method thereof | |
| CN113402869A (en) | PGA modified blown film material and preparation method thereof | |
| Toh et al. | Influence of compounding methods on poly (vinyl) alcohol/sago pith waste biocomposites: mechanical and water absorption properties | |
| CN112063099A (en) | Degradable ABS plastic and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20211015 Address after: 641402 group 12, Shunjiang village, Yangma Town, Eastern New Area, Chengdu, Sichuan (within the scope of Jianzhou new town) Applicant after: Sichuan gutefis Technology Co.,Ltd. Address before: 528139 No.6, Jiuxiang, Changshuo village, dushugang, Lubao Town, Sanshui District, Foshan City, Guangdong Province Applicant before: Cai Baohong |
|
| TA01 | Transfer of patent application right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20221129 Address after: 641300 Wenfeng Industrial Park, Tongjia Development Zone, Lezhi county, Ziyang City, Sichuan Province Patentee after: Ziyang zhongnuocheng plastic products Co.,Ltd. Address before: 641402 group 12, Shunjiang village, Yangma Town, Eastern New Area, Chengdu, Sichuan (within the scope of Jianzhou new town) Patentee before: Sichuan gutefis Technology Co.,Ltd. |
|
| TR01 | Transfer of patent right |