JPH07507827A - Lactic acid polymer degradable by water and UV light - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Contract origin of lactic acid polymer invention degradable by water and ultraviolet light Agreement between the University of Chicago, which represents the Argon National Laboratory, and the U.S. Department of Energy. Pursuant to Contract No. W-31-109-ENG-38, the U.S. Government granted this invention. shall have the right to do so.

Background of the invention The present invention is a material that is safe for the environment and can be decomposed by water or ultraviolet light. Improved waste treatment or agriculturally useful ports developed for the purpose of providing Relating to remers and polymer blends. these The material is environmentally safe and naturally produced by exposure to water or ultraviolet light. decomposes into substances that Improved polymers and polymer blends can be used in garbage bags or can be used for other disposal purposes and only environmentally safe substances are produced when burned It can be incinerated.

Many plastic materials used in packaging and waste disposal end up in landfills. It does not decompose when treated with water and produces toxic substances when incinerated. This causes serious environmental problems.

Interest in environmentally safe plastic materials is increasing day by day, and 135,000 More than 639,000 pieces of plastic are dumped into the ocean every year (dI). It is a matter of concern that plastic containers and bags are being dumped into the ocean every day. This was confirmed at the hearing of the Board of Directors. In addition to this intolerable situation, packaging and trash Large amounts of non-degradable plastic materials used for processing are disposed of in municipal waste. Filling up a landfill that was previously considered a perfectly suitable place to dump things This makes the landfill site unusable. Waste treatment in the U.S. and worldwide has become a very serious problem.

This makes it a suitable plastic material for packaging and waste disposal, making it environmentally safe. There is a growing need for plastic materials that can be biodegraded by living organisms into .

Waste containing higher carbohydrates produced as cheese and whey in the United States By collaborating with potato processing factories, we use lactic acid as a raw material in an environmentally friendly process. It has recently been confirmed that it can be used for other purposes. Lactic acid is a naturally occurring substance It can be said to be a preferable substance because it decomposes into environmentally safe substances. In addition to this, lactic acid Oligomers of have been found to be useful as plant growth promoters, including Accordingly, U.S. Patent No. 4 was granted to Kinnersley Pond in March 1989, 21U3. No. 813.997.

Converting waste containing higher carbohydrates into feedstock for producing lactic acid is This is the result of research at the Argon Institute, and along with this and other discoveries, the book is Invented various copolymers of lactic acid widely used in agriculture and packaging. Mixtures of polymers can be formed. These various copolymers and lactic acid A mixture of polymers is a material that fulfills all of the above objectives. Also, these materials is an environmentally safe alternative to the plastics currently in use that are difficult to dispose of safely. It can be said that it is a material.

Therefore, the object of the present invention is to improve the ability of decomposition by water and ultraviolet rays, An improved lactic acid polymer useful in at least one of the packaging industry and the waste industry. The purpose of the present invention is to provide a reamer or a mixture thereof.

Another object of the invention is that the invention is capable of decomposition by water or by ultraviolet light; is an environmentally safe substance and is used in agricultural fields to provide plant growth promoters. polylactic acid polymers and mulch that can be used as degradable agricultural dressings and mulches. and copolymers.

Another object of the invention is a water-degradable modified polylactic acid polymer comprising lactic acid It has a copolymer of monomers and adjusting monomers, and the adjusting monomers are ethylene. polyethylene glycol, propylene and polypropylene glycol, p -dioxanone, 1,5-dioxeban-2-one, 1,4-oxathialane- 2-one selected from the class consisting of 4,4-dioxides and mixtures thereof. and the ethylene glycol is in the range of about 5% to about 40% by weight. and the propylene glycol is present in the range of about 5% to about 40% by weight. p-dioxanone, 1,5-dioxeban-2-one or 1 ．． 4-Oxathialan-2-one 4,4-dioxide is about 2% by weight to about 4% by weight 0% by weight, and the conditioning monomer is present in the conditioned polylactic acid polymer. An object of the present invention is to provide a modified polylactic acid polymer comprising less than about 40% by weight of the polylactic acid polymer.

Yet another object of the invention is a polylactic acid polymer that is degradable by water and ultraviolet light. Therefore, a copolymer consisting of lactic acid and a regulating monomer is provided, and the regulating monomer is p-dioxanone in an amount up to about 20% by weight and 1° in an amount up to about 20% by weight. 5-dioxeban-2-one and 1,4-oxathiala in an amount up to about 20% by weight selected from the class consisting of ion-2-one 4,4-dioxide; or a mixture thereof, wherein the conditioning monomer is less than about 20% by weight. The object of the present invention is to provide polylactic acid polymers present in the proportions.

Still another object of the present invention is to provide a mixture of polylactic acid and high molecular weight polyethylene oxide. A compound containing from about 2% to about 50% by weight of high molecular weight polyethylene oxide The object of the present invention is to provide a mixture of substances which can be decomposed by water present within the range of %.

Yet another object of the present invention is to provide agricultural land with seeds, seedlings, pesticides, herbicides, fertilizers and the like. A method of applying an active substance selected from a class consisting of a mixture of lactic acid and Monomers and ethylene and polyethylene glycol, propylene and polyethylene glycol, p-dioxanone, 1,5-dioxeban-2-one, 1゜4- Oxathialan-2-one consisting of 4,4-dioxide and mixtures thereof preparing a copolymer having a modulating monomer selected from the class; , the ethylene glycol is present in the range of about 5% to about 40% by weight; The propylene glycol is present in the range of about 5% to about 40% by weight; p-dioxanone, 1,5-dioxeban-2-one or the above 1,4-oxanone, Sachialan-2-one 4,4-dioxide is about 2% to about 40% by weight. The conditioning monomer is present within a range of about 4% of the conditioned polylactic acid polymer. a combination of said copolymer and said active substance, occupying less than 1% by weight of 0f; and the active substance comprises from about 60% to about 9% by weight of said combination. 8% by weight, and applying said combination to agricultural land. The purpose is to provide a method consisting of.

The invention resides in certain novel features, and combinations of which are disclosed in detail below. Therefore, the details of the invention as set out in the appended claims are as follows: Various modifications may be made without departing from the spirit of the invention or without detracting from the advantages of the invention. It is possible to implement it without sacrificing it.

Detailed description of the invention Lactic acid polymers and copolymers have a wide range of properties similar to traditional thermoplastics. It is a colorless and transparent thermal DJ plastic with excellent physical properties. add moisture , or contact with biological fluid The improved plastic is gradually hydrolyzed over several months and becomes milky. It breaks down into naturally occurring harmless substances such as acids. Copoly of lactic acid and glycolic acid Mer is a resorbable thread (resorbable 5tures). First developed and sold as a product.

These polymers and copolymers have high strength and biocompatibility as well as In addition, its decomposition can be controlled.

Are lactic acid and glycolic acid polymers prepared by condensation polymerization of free acids? , or by opening the ring of dilactone using a catalyst. can be adjusted. Lactic acid polymers and glycolic acid polymers are naturally occurring Both are decomposed into lactic acid and glycolic acid, which are harmless substances present. Both can be adapted to the environment. These polymers can be added with other specific substances. While more primarily degraded by hydrolysis, these polymers are Decomposition is possible by exposure to an ultraviolet light source. When incinerating these pots, The rimmer does not contain harmful or corrosive gases such as those found when many plastics are burned. Burns with a clean blue flame without producing any gas.

Thermoplastics based on lactic acid polymers degrade over a period of several weeks to a year. The fact that the products are disaggregated has the advantage of providing relatively reasonable product shelf life. Score points. Water-soluble polymers that separate quickly in water or swell with water The improved polymer degrades more slowly than the improved polymer. These polymers are classified as moisture-sensitive polymers. For example, lactic acid polymers and Certain copolymers show a decrease in molecular weight even after being immersed in water for several months. I didn't. However, the physical properties of these materials decreased significantly after 6 months.

For example, water-degradable polylactic acid copolymers combine lactic acid monomers with ethylene. polyethylene glycol, propylene and polypropylene glycol , p-dioxanone, 1.5 dioxeban-2-one, 1,4-ogizathiaran -2-one, 4,4-dioxide and various mixtures thereof and adjusting monomers selected from the following. crystallinity, melting point, Degradation rate, elasticity, and similar physical properties depend on the amount and temperature of copolymer formed. Varies depending on the type.

The elasticity of materials varies from glass-like materials with low elasticity to materials with high elastic modulus. . Also, the degradation rate of the material is determined by the lactic acid polymer or glycolic acid polymer used. Varies between medium, fast, very slow, and none based on the amount of

In general, the various physical properties mentioned above depend on the type of copolymer used as the final material. can vary widely based on the amount of milk produced and the desired end use. It is important to contain 5-40% by weight of conditioning polymer for the acid polymer; This allows it to have physical properties suitable for the end use purpose and is resistant to decomposition by water. Possible improved polylactic acid copolymers are provided.

It is anticipated that various copolymers of lactic acid will be suitable for a variety of agricultural and waste treatment applications. It will be done. For example, copolymers can be used as coating materials or as matrices. This matrix can be used for seeds, seedlings, pesticides, herbicides, fertilizers and their mixtures. It can be used as a matrix for compounds. These coating materials or lix provides a controlled release of applied or embedded active materials. This release depends on the thickness of the active material applied onto the matrix, or Proceeds based on the concentration of active material embedded within the matrix. The coating material is It can be formed to a thickness of approximately 0.25 to 4 microns, which allows for The release rate of the active material can be varied accordingly. Seeds, pesticides, herbicides, fertilizers , and mixtures thereof, are mixed with the copolymer and processed by extrusion. The active material is dispersed within the matrix. It is in. Here, the release of the active material depends on the type of copolymer and the amount of copolymer contained. It can be controlled by changing the amount. matrix of active materials When a copolymer is used as , i.e., the active material preferably accounts for about 60-98%. Therefore, urea or be coated with other nitrogen-rich fertilizers in varying thicknesses, or It is possible to disperse it within a matrix. This can result in excessive urea or Crop burning that occurs when other fertilizers are temporarily released. ) or other undesirable side effects, coated active materials, or Continuous release of dispersed active material can be carried out over a wide range of time becomes.

Generally, copolymers of lactic acid with molecular weights of about 20,000 to 100,000 are Useful as a dressing or matrix. Agricultural mulch and sheet materials are required. Copolymers with molecular weights greater than about 25,000 are preferred, especially when required. Copolymers with molecular weights between 25,000 and 100,000 are preferred for agricultural mulch. Indeed, these copolymers degrade when exposed to moisture or UV light. It breaks down into lactic acid and other monomers that make up the copolymer.

Copolymers are used as matrices or coatings for active materials, especially in agriculture. It is used a lot. From 11;j, lactic acid polymers are used as drugs in the medical field. Which capsules are used and what is the preparation of the encapsulated active material? 1095~, Volume 36, No. 3 of the Journal of Chemistry and Pharmacology, published in 1988. "Lactic acid polymer, polylactic acid copolymer" written by Koyou et al. on page 1103 or Leuprola in microcapsules made of polyglycolic acid copolymer. A new technique for the effective encapsulation of idoacetate was disclosed in a paper titled The disclosure of this paper shall be deemed to have disclosed its contents in this application. Furthermore, La A method for preparing microcapsules of cutide or lactide copolymers was published in 1987. Disclosed in U.S. Patent No. 4,637,905, issued to Gardner on January 20, 2013. This disclosure is deemed to be the content thereof disclosed in this application. similarly In the field of pharmacology, the encapsulation of drugs into microcapsules began on November 1, 1986. No. 4,622,244, issued to Love, et al. , the contents thereof are deemed to have been disclosed in this application with this disclosure.

The various improved monomers forming the new copolymers have high crystallinity. from crystalline to amorphous, and from high to low melting points. It exhibits a wide range of physical properties, including melting points. Therefore, from these monomers irradiating the copolymer with ultraviolet light and adding moisture. Decompose these copolymers by performing at least one of the following: It becomes possible to control the rate of decomposition during decomposition.

``1 Milk, which is beneficial to the environment and is an inexpensive material for forming capsules. Pesticide slow release system using acid and glycolic acid polymers Sinclair's paper, titled '', combines glycolic and lactic acids to It discloses that it can be used as a matrix for Especially used as a conditioning agent Polypropylene glycol and polyethylene glycol are It belongs to a different class from the glycolic acid disclosed by Rhea.

The present invention allows for the formation of copolymers that control the rate of release of active materials into the environment. do. Matrix control if the active material is a fertilizer with a high urea content urea production at a rate that does not cause crop blight or other undesirable side effects. It is permissible to emit. If the active ingredient is a herbicide or insecticide, Controlled decomposition of the lix allows for long-term continuous release of pesticides or herbicides. release and allow farmers to apply even lower amounts of these chemicals. In the end, only the required amount is released at any given time. This will further reduce the amount of active material released into the environment.

This results in lower amounts of chemical application and even lower amounts of active material used. Since it is possible to eliminate this, agricultural workers can reduce their financial expenses.

Still other features and advantages of the invention provide a matrix or coating for seeds or seedlings. The present invention relates to the use of improved polylactic acid polymers as materials. for germination or growth growth-promoting lactic acid polymer oligomers or modified polylactic acid copolymer. When the copolymers disclosed in this application are used as remers, they are Decomposed. When the copolymers disclosed herein degrade on agricultural land, a wide variety of chains are generated. Various types of lactic acid polymers with a length or molecular weight of 4T and copolymers thereof of oligomers are added to agricultural land. Some of these are known to be growth promoters. It has been confirmed that

Agriculture and waste management require a wide variety of products such as agricultural mulches and trash bags. These agricultural mulches and trash bags are designed to meet the physical properties of the selected polymer. It is then decomposed over a wide range of time. For example, agricultural mulch can be used for several days to several days. Can be configured to decompose over a period of months. However, plastic garbage bags is not formed so as to be decomposed between the numbers 11. to form a film A mixture of lactic acid polymer and high molecular weight polyethylene oxide is preferred.

In order to form even better films, high molecular weight components exceeding about ioo, ooo Polyethylene oxide with a molecular weight of about 25,000 to 100 It is mixed with a lactic acid polymer in the range of 0.0000000. In particular, high molecular weight polyester The tyrene oxide is present as a mixture at about 2 to 50% by weight of the total polymeric material. When used, it is possible to form excellent films. This is a copo like the one above. Lactic acid polymer and molecule-high f4 polyethylene oxide rather than reamer refers to the physical mixing of the copolymers formed during this physical mixing. It will not be done. However, lactic acid polymers and polyethylene with high molecular weight - These mixtures of oxides form films with excellent physical properties. Na The lactic acid polymer used in this case is one with the above-mentioned changes, and a glycolytic acid polymer. Either with addition of oleic acid monomer or without any modification That's it.

Furthermore, when these mixtures are used in films such as garbage bags, they cannot be exposed to ultraviolet light. It can even become a film that decomposes. Situations where such ultraviolet rays do not hit can be found in garbage dumps, etc.

Although preferred embodiments of the present invention have been disclosed hereinbelow, the details of the present invention will be described hereinafter. Many modifications may be made without departing from the spirit of the invention and without sacrificing the advantages of the invention. It is possible to implement changes.

Copy and translation before amendment) submission form (Article 184-8 of the Patent Law)

Claims (29)

[Claims] 1. A modified polylactic acid polymer decomposable by water, comprising lactic acid monomer and modified polylactic acid polymer. copolymer of ethylene and polyethylene. glycol, propylene and polypropylene glycol, p-dioxanone, 1,5-dioxepan-2-one, 1,4-oxacharan-2-one 1,4- selected from the class consisting of carbon dioxide and mixtures thereof; The ethylene glycol is present in the range of about 5% to about 40% by weight; Propylene glycol is present in the range of about 5% to about 40% by weight; -dioxanone, 1,5-dioxepan-2-one or 1,4-oxathia Ran-2-one 4,4-dioxide is in the range of about 2% to about 40% by weight. exists, The conditioning monomer accounts for less than about 40% by weight of the prepared polylactic acid polymer. Adjusted polylactic acid polymer. 2. 2. The aqueous copolymer of claim 1, wherein the copolymer has a molecular weight greater than about 20,000. Modified polylactic acid polymer that is more degradable. 3. The molecular weight of the copolymer is within the range of about 20,000 to about 100,000. A modified water-degradable polylactic acid polymer according to claim 1. 4. The polymer consists of seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof. By water according to claim 3 present as a coating on particles selected from the class Degradable modified polylactic acid polymer. 5. The polymeric coating has a thickness within the range of about 0.25 microns to about 4 microns. 5. The water-degradable modified polylactic acid polymer according to claim 4, having a 6. The polymer is in the form of a thin sheet and has a molecular weight greater than about 25,000. The water-degradable modified polylactic acid polymer of claim 1. 7. 7. The molecular weight of claim 6 is within the range of about 25,000 to about 100,000. A water-degradable modified polylactic acid polymer. 8. The polymer may be mixed with fertilizers, pesticides, herbicides, seedlings, seeds and mixtures thereof. 2. The water-degradable compound according to claim 1, wherein the water-degradable Modified polylactic acid polymer. 9. Polylactic acid polymer decomposable by water and ultraviolet light, used for lactic acid and conditioning comprising a copolymer consisting of monomers, the regulating monomer being up to about 20% by weight. p-dioxanone in an amount of up to about 20% by weight and 1,5-dioxebane-2 in an amount of up to about 20% by weight. -one and up to about 20% by weight of 1,4-oxathialan-2-one 4,4- selected from the class consisting of carbon dioxide, or a mixture thereof. can be, The conditioning monomer is present in less than about 20% by weight of the polylactic acid polymer. -. 10. 10. The copolymer according to claim 9, wherein the molecular weight of the copolymer is greater than 20,000. A polylactic acid copolymer that can be decomposed by UV light and UV light. 11. The molecular weight of the copolymer is within the range of about 20,000 to about 100,000. The polylactic acid copolymer degradable by water and ultraviolet light according to claim 10. 12. The copolymer can be obtained from seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof. 12. Water according to claim 11, present as a coating on particles selected from the class: and UV-degradable polylactic acid polymers. 13. The copolymer coating is within the range of about 0.25 microns to about 4 microns. 13. The water- and UV-degradable polylactic acid copolymer according to claim 12, having a thickness of Rimmer. 14. The copolymer is in the form of a thin sheet and has a molecular weight greater than about 25,000. The polylactic acid copolymer decomposable by water and ultraviolet light according to claim 11, having . 15. The copolymer can be obtained from seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof. Claim 11 is present as a matrix for an active substance selected from the class consisting of: A polylactic acid copolymer degradable by water and ultraviolet light as described in . 16. The matrix in combination with the active substance 16. The water and ultraviolet light of claim 15 present in the range of about 2% to about 40% by weight. Polylactic acid copolymer that can be decomposed by radiation. 17. A mixture of polylactic acid and high molecular weight polyethylene oxide, molecular weight of polyethylene oxide is present in the range of about 2% to about 50% by weight. Mixed substances that can be decomposed by water. 18. High molecular weight polyethylene oxide has a molecular weight greater than about 100,000 and the polylactic acid has a molecular weight greater than about 20,000. Mixed substances that can be decomposed by water. 19. The mixture consists of seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof. A coating on a particle selected from a class or a coating on a matrix containing that particle. 18. A water-decomposable mixture according to claim 17, present as a covering material. 20. The polylactic acid polymer includes glycolic acid, ethylene and polyethylene glycol. Coal, propylene and polypropylene glycol, p-dioxanone, 1,5 -dioxepan-2-one, 1,4-oxathialan-2-one 1,4-diox Tailored by monomers selected from the class consisting of side and mixtures thereof The adjusting monomer is about 40% of the combined polylactic acid and adjusting monomer. 18. The water-decomposable mixture of claim 17, wherein the water-decomposable mixture is present in an amount of up to %. 21. The substance is in the form of a thin sheet, and the molecular weight of the polylactic acid for adjustment is approximately 25,00. 21. The water decomposable mixed material of claim 20, which is greater than 0. 22. Agricultural land contains seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof. A method of applying an active substance selected from lactic acid monomer and ethylene polyethylene glycol, propylene and polypropylene glycol, p-dioxanone, 1,5-dioxepan-2-one, 1,4-oxathialane selected from the class consisting of -2-one 4,4-dioxides and mixtures thereof; a copolymer having the ethylene copolymer; The recall is present in the range of about 5 weight percent to about 40 weight percent, and the propylene glycol The coal is present in the range of about 5% to about 40% by weight and the p-dioxanone , 1,5-dioxepan-2-one or the 1,4-oxathiaran-2- 4,4-dioxide is present in the range of about 2% to about 40% by weight; The conditioning monomer accounts for less than about 40% by weight of the prepared polylactic acid polymer. forming a combination of said copolymer and said active substance; of the active substance is present in the range of about 60% to about 98% by weight of said combination. Being and applying said combination to agricultural land. 23. Film or sheet material used in combination as agricultural mulch 23. The method of claim 22, comprising: 24. The active substance is a seed and the copolymer decomposes in agricultural fields to produce lactic acid. 23. The method of claim 22, wherein the method is present as an oligomer-producing coating. 25. The active substance used is a fertilizer and the conditioning polymer is a matrix for it 23. wherein the carbon dioxide is present in the range of about 2% to about 10% by weight. the method of. 26. 2. The modified copolymer is present in a range of about 2% to about 5% by weight. The method according to item 25. 27. The active substance is an insecticide and the copolymer is a matrix therefor. of claim 22, present in the range of about 2% to about 40% by weight. Method. 28. The modified copolymer may be present in the range of about 5% to about 10% by weight. The method according to claim 27. 29. The growth promoter is released by decomposing the copolymer by exposing it to light and moisture. The method further includes a step of waiting for a predetermined period of time to produce various oligomers containing 23. The method according to claim 22.