# US 11,992,007 B2 · Aqueous formulation that reduces damage caused by spring frosts in plants and production method thereof

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- Number: US 11,992,007 B2
- Document ID: US11992007B2
- Status: Granted
- Kind: B2
- Application number: 17/632,152
- Filed: 2020-08-11
- Published: 2022-10-06
- Granted: 2024-05-28
- Earliest claimed: 2019-08-14
- Assignees: Universidad De Concepcion; Centro De Investigacion De Polimeros Avanzados
- Applicants: Universidad De Concepcion; Centro De Investigacion De Polimeros Avanzados
- Inventors: Saddys María Rodriguez Llamazares; Constanza Sabando Correa; Walther Ide; Richard Mauricio Bastias Ibarra
- Web page: https://patentgrep.com/patent/US11992007B2

## CPC

- A01N 25/10: Macromolecular compounds
- A01N 3/00: Preservation of plants or parts thereof, e.g. inhibiting evaporation, improvement of the appearance of leaves {or protection against physical influences such as UV radiation using chemical compositions} (preservation or chemical ripening of fruit or vegetables A23B7/00); Grafting wax
- C08J 3/03: in aqueous media
- C09D 129/04: Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
- C08J 2329/04: Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
- A01N: PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF (preservation of food or foodstuff A23); BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES (preparations for medical, dental or toiletry purposes which kill or prevent the growth or proliferation of unwanted organisms A61K); PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
- C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29)
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)

## Abstract

An aqueous formulation that reduces the damage caused by spring frosts in plants having: (a) 0.001-2% by weight PVA micro/nanoparticles having a molecular weight of 10,000-100,000 g/mol and 1-20% acetate groups; (b) 0.0001-0.4% by weight stabilising agents; (c) 0.0005-0.05% by weight category IV adjuvants; (d) 0.00025-4% by weight emulsifier; (e) 0.003-6% by weight sodium hydroxide; and (f) 0.0065-13% by weight hydrochloric acid at 37% weight/weight and 1.18 g/mL density; a process for producing the aqueous formulation, and to uses.

## Claims

### Claim 1

An aqueous formulation that reduces spring frost damage to plants wherein it comprises at least the following components:
i. 0.001-2% by weight of polyvinyl alcohol (PVA) micro/nanoparticles of molecular weight between 10,000-100,000 g/mol and percentage of acetate groups between 1 and 20%;
ii. 0.0001-0.4% by weight of stabilizing agents;
iii. 0.0005-0.05% by weight of adjuvants;
iv. 0.00025-4% by weight of emulsifier;
v. 0.003-6% by weight of sodium hydroxide; and
vi. 0.0065-13% by weight of hydrochloric acid, wherein the % weight is based on the hydrochloric acid at 37% w/w and 1.18 density g/ml of the hydrochloric acid.

### Claim 2 (depends on 1)

The aqueous formulation that reduces spring frost damage to plants according to claim 1, wherein the stabilizing agent is polyvinylpyrrolidone and/or nonionic surfactants.

### Claim 3 (depends on 1)

The aqueous formulation that reduces spring frost damage in plants according to claim 1, wherein the emulsifier is soy lecithin.

### Claim 4 (depends on 1)

A process for producing the aqueous formulation of claim 1 comprising the following steps:
a. dissolving polyvinyl alcohol (PVA) in water in at least a 1/50 ratio in a mineral bath and with temperatures fluctuating between 40-100° C., depending on the molecular weight and degree of hydrolysis of the PVA and for at least 2 hours, using agitation with speeds between 500-900 rpm;
b. dissolving sodium hydroxide in water at room temperature (20° C.), using agitation with speeds between 500-900 rpm and concentrations fluctuating between 2-8% weight/volume;
c. obtaining PVA micro/nanoparticles: the solution obtained in stage “a” is mixed in a reactor containing the solution of stage “b” in a 1/1 ratio, by dripping using a peristaltic pump with a flow rate of 10-50 ml/h and using agitation with speeds between 700-8000 rpm, to obtain PVA micro/nanoparticles whose size varies between 300-3000 nm;
d. neutralizing the dispersion obtained in step “c” with hydrochloric acid up to pH 7, using agitation with speeds between 100-300 rpm; and
e. mixing the neutralized dispersion in a reactor with stabilizers, emulsifiers and/or adjuvants in a 1/10 ratio at room temperature, using agitation with speeds between 4000-8000 rpm.

### Claim 5 (depends on 1)

A method of inhibiting recrystallization of ice in plants comprising applying the aqueous formulation of claim 1 to the plant to inhibit recrystallization of ice.

### Claim 6 (depends on 1)

A method of reducing damage in plants comprising applying the aqueous formulation of claim 1 to the plant to reduce damage in conditions of frosts down to −5° C. and for 4 hours.