WO2003002638A1

WO2003002638A1 - A kind of biodegradable composite material as well as the process for making disposal products using the said material

Info

Publication number: WO2003002638A1
Application number: PCT/CN2002/000388
Authority: WO
Inventors: Tet Siong Ong
Original assignee: G5 Manufacturing (Suzhou) Ltd.
Priority date: 2001-06-06
Filing date: 2002-06-04
Publication date: 2003-01-09
Also published as: CN1371944A; CN1151206C

Abstract

A kind of biodegradable composite material as well as the process for making disposal products, the material is composed of 35-55 wt% urea formaldehyde moulding power, 33-58 wt% starch, 4-11 wt% medium CaCO?, 2-3 wt% vegetable fibres; the vegetable fibre mentioned above can be any one among the rice-husk, sugar cane, corn, peanuts-husk and plants straw. The process is as follow: grinding the raw materials; mixing and formulating the raw materials; molding and forming twice, the specific pressure is settled at 300-450 kg/cm∫, the temperature is settled at 120-180ΩC, the temperature and pressure holding time is 25-80 seconds; taking the products out from the mould, then do some finishing. The advantages of the invention are as follow: faster degradation, low cost, good properties, simple technology, powerful practicability, suitable for disposal products, food package, article package as well as disposal medical things etc.

Description

Fully degradable material and method for preparing disposable products using the same

The invention relates to a fully degradable material and a method for preparing a single-use, degradable product by using the material. The above-mentioned disposable degradable products include disposable tableware, food packaging, article packaging, and disposable medical supplies. Background technique

As everyone knows, the "white pollution" caused by disposable tableware has become a prominent problem in the treatment of environmental pollution in today's society. Governments and environmental experts around the world have recognized the disaster and harm caused by "white pollution" to the human environment and are taking active measures to address it. Many European countries have long banned the use of non-degradable disposable tableware and plastic packaging products. In China, biodegradable plastics have been listed as key research projects in the Eighth Five-Year Plan period and key promotion projects in the Ninth Five-Year Plan period. The treatment of "white pollution" has received great attention from government departments at all levels and has become a major issue of concern to the whole society. Many cities have begun to ban the use of disposable PS tableware, and many companies and researchers are actively engaged in the research and development of degradable alternatives for this topic. In recent years, Chinese patents have successively disclosed many technical solutions on the subject of this technology. They can be summarized into the following four categories. The first category is made by the pulp molding method; the second category is made from whole starch. The third category is made of decomposable plastic materials; the fourth category is made of plant fiber materials. Although the various technical solutions mentioned above have proposed many measures from different angles and achieved positive results, there are still many problems from the practical application point of view, for example, the pulp molding production cost is high, and the emissions during the production process will bring black pollution. . The whole starch-based production process is pollution-free, but the price of raw materials is high. Decomposable plastic products cannot be completely degraded into harmless substances. Plant fiber products need to be burned to quickly degrade. The above defects directly affect the substitution effect of the existing degradation products to varying degrees, and it is also one of the problems that "white pollution" in China has not been solved. Summary of the Invention The purpose of the present invention is to provide a fully degradable material with fast degradation, low cost, good performance, simple process and strong practicability, and a method for preparing disposable products by using the material.

In order to achieve the above-mentioned object, the first technical solution adopted by the total degradable material of the present invention is: a fully degradable material for preparing disposable products, containing raw materials and weight percentages of the following components: amino molding compound 35-55% by weight;

Starch 33 ~ 58% by weight;

Intermediate calcium carbonate 4 ~ 11% by weight;

Plant fiber material 2 ~ 3% by weight;

The plant fiber material is one of rice husk, crop straw, bagasse, corn cob, and peanut husk. The formula is suitable for the preparation of disposable biodegradable tableware, food packaging and disposable medical supplies. The amino molding compound in the scheme plays the role of toning and binder in the formula, starch plays the role of degradation, aldehyde trapping and filler in the formula, and the intermediate calcium carbonate acts as a degrading agent, modification and filler in the formula. Function, the plant fiber material plays a filler role in the formula.

The "amino molding compound" in the present invention refers to a thermosetting plastic formed by reacting a monomer containing an amino group (^) or an amide group (-CONH-) with formaldehyde. It belongs to General Plastics. It usually includes the following materials:

-Urea-formaldehyde plastic, which is based on urea-formaldehyde resin, ct-fiber as filler, and added with curing agent, lubricant, and colorant. The color of the system is jade, and it is also called electric jade plastic;

-Urine melamine plastic, which is based on urine melamine formaldehyde resin, α-fiber as filler, and added lubricant, colorant, etc .;

-Triammonium formaldehyde plastic, which is based on triammonium chloride formaldehyde resin, α-fiber as filler, and added lubricant, colorant, etc .;

-Melamine plastic (melamine benzoguanidine plastic), which is based on melamine benzoguanidine formaldehyde resin, ct-fiber as the filler, titanium dioxide as the filler, and adding lubricants.

The "starch" in the present invention includes not only starch, but also flour, soy flour, and the like containing starch as a main component.

In the above technical solution, the following two formulas can be generated according to the requirements of the degradation period: 1. In order to make the degradable material completely degrade within 180 days (6 months), the raw material components and weight percentages are:

Amino molding compound 36 ~ 44% by weight; 47 ~ 58% starch

Medium calcium carbonate 4 ~ 6% weight;

Plant fiber material 2 ~ 3% by weight;

Since the weight of degradable raw materials in this formula accounts for more than 50% by weight, the degradation rate is fast. 2. In order for the degradable material to be completely degraded within 6 to 12 months, its raw material components and weight percentages are:

Amino molding compound 45 ~ 55% weight;

Starch 33 ~ 42% by weight;

Medium calcium carbonate 9 ~ 11% by weight;

Plant fiber material 2 ~ 3% by weight.

In order to achieve the above purpose, the second technical solution adopted by the fully degradable material of the present invention is: a fully degradable material for preparing disposable products, containing raw materials and weight percentages of the following components-amino molding compound

18 ~ 22% starch

Medium calcium carbonate 4 ~ 6% weight;

Plant fiber material 20 ~ 25% by weight;

Water 2 ~ 3% by weight;

The plant fiber material is one of rice husk, crop straw, bagasse, corn cob, and peanut husk. The degradation materials described in this solution can be completely degraded within 6-12 months. This formula is suitable for the preparation of general goods packaging. The amino molding compound in the scheme plays the role of toning and binder in the formula, starch plays the role of degradation, aldehyde trapping and filler in the formula, and the intermediate calcium carbonate acts as a degrading agent, modification and filler in the formula. Function, the plant fiber material plays a filler role in the formula.

The fully degradable material of the present invention can be used to prepare disposable products including, but not limited to, fully degradable tableware, food packaging, article packaging, and disposable medical supplies.

In order to achieve the above object, the present invention provides a method for preparing a disposable product using the above-mentioned fully degradable material.

According to one aspect of the present invention, a method for preparing a disposable product using a fully degradable material is provided, including the following steps:

(1) Crush the plant fiber material to 100-200 mesh; (2) mixing 35 ~ 55% by weight amino molding compound, 33 ~ 58% by weight starch, 4 ~ 11% by weight medium calcium carbonate, and 2 ~ 3% by weight plant fiber material to obtain a mixture;

(3), adding the mixture to the initial pressure of the mold in the mold cavity, open the mold once and exhaust, the initial pressure unit pressure is 300 ~ 450kg / cm ² , the temperature is 120 ~ 180 ° C;

(4) Re-clamping and hot-pressing curing molding, the unit pressure is 300 ~ 450kg / cm ² , and the temperature is

120 ~ 180 ° C, heat preservation and pressure curing time 25 ~ 80 seconds;

(5) The product is obtained by demolding and post-processing.

According to another aspect of the present invention, a method for preparing a disposable product using a fully degradable material is provided, including the following steps-(1) pulverizing the plant fiber material to 100-200 mesh;

(2) Mix 20 ~ 25% by weight of plant fiber material with 2 ~ 3% by weight of water, and then mix with 45 ~ 55% by weight of amino molding compound, 18 ~ 22% by weight of starch and 4 ~ 6% by weight of medium carbonic acid Calcium mixed and stirred to obtain a mixture;

(3) Add the mixture to the initial pressure of the mold in the mold cavity, open the mold once and bleed it once, the initial pressure unit pressure is 300 ~ 450kg / cm ² , and the temperature is 120 ~ 180 ° C _;

(4) Re-molding and hot-pressing and curing, the unit pressure is 300 ~ 450kg / cm ² , the temperature is 120 ~ 180 ° C, and the heat preservation and pressure holding curing time is 25 ~ 80 seconds;

(5) The product is obtained by demolding and post-processing.

In the first step of the above technical solution, in general, the amino molding compound, starch, and medium calcium carbonate are powdered, and the particle size of the amino molding compound and starch is above 140 mesh. If the configured raw materials do not meet the particle size requirements, It should also be crushed to 140 mesh.

In the third step of the above technical solution, the unit pressure is preferably 370 to 430 kg / cm ² and the temperature is 140 to 160 ° C.

In the fourth step of the above technical solution, the unit pressure is preferably 370 to 430 kg / cm ² , the temperature is 140 to 160 ° C, and the heat preservation and pressure curing time is 40 to 60 seconds.

The third step initial pressure and the fourth step forming pressure of the above technical solution may be continuously completed by using the same pair of molds, or may be separately pressed by using two pairs of molds.

In the fifth step of the above technical solution, the post-processing mainly includes trimming and disinfection. The disinfection can be disinfected by ultraviolet sterilization, and the temperature is controlled at about 300 ° C. Other conventional disinfection methods can also be used. Due to the application of the above technical solutions, the present invention has the following advantages and effects compared with the prior art:

1. The sample of the present invention "Migration Test: Determination of Heavy Metals" is reported below-

(1) Testing unit

The Singapore Productivity and Standards Board (PSB), the statutory management board with 1,000 employees in Singapore, conducts migration testing. PSB helps local companies access global markets by ensuring that processes and products directly adapt to international standards.

(2), subject

Identification of heavy metals in samples prepared from "biodegradable materials" composed of agricultural fibers. This test was completed on October 2, 2000, and the test report number is 29S0002989-EO.

(3), sample description

Samples prepared from "biodegradable materials" composed of agricultural fibers are described below: a. Disposable table supplies

b. Horticultural products

c. Packaging materials

d. Medical devices

(4), test method

EN71-3 is a European standard approved by the European Committee for Standardization (CEN) on December 13, 1994. CEN's members are the National Standards Institutes of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. According to CEN / CENELEC internal regulations, these countries must implement this European Standard.

A. EN71: Part 3, March 1995 "Safety of Toys", Part 3 "Determining Technical Conditions for Element Migration".

B. Test the mercury content by atomic absorption spectrometer-cold vapor method.

C. Test other elements by inductively coupled plasma-atomic divergence spectrophotometry.

(5) Test results

Elemental biodegradable materials EN71 Part 3 1995 Antimony SB (mg / kg) <5.0 maximum 60 As As (mg / kg) <5.0 maximum 25 Barium Bs (mg / kg) <5.0 maximum 250 cadmium Cd (mg / kg) <0.5 maximum 50 chromium Cr (mg / kg) <0.5 maximum 25 lead Pb (mg / kg) <5.0 maximum 90 mercury Hg (mg / kg) <0.5 maximum 25 selenium Se (mg / kg) <5.0 maximum 500 (6), explanation

The requirements of this standard are based on the bioavailability caused by the use of toys, and each object should not exceed the daily level of the above list (test result column 3). Measurements are in milligrams per kilogram (mg / Kg).

Sample test results (column 2 of the test results table) are far from their upper limits.

2. The invention has fast degradation speed, high temperature resistance, freeze resistance, water resistance and good strength. According to GB6344 -1996 "Determination of tensile strength and elongation at break of soft foam polymer materials" and GB3681-2000 "Test method for atmospheric exposure of plastics", the physical and chemical properties of the product of the present invention are tested and determined as:

Tensile strength ^ 1.5MPa

Elongation at break 2%

Temperature resistance 80 ~ 100 ° C without obvious deformation

Degradation time Under the condition of humidity of 80% at 25 ° C, the start and end days of degradation are 7 to 60 days. Resistance to water and water resistance Immersion in water at 80 to 100 ° C for 2 hours without obvious deformation

3. The product of the present invention is white or milky white, has a slightly scented food, and has an attractive and hygienic appearance. It is generally close to the existing disposable PS tableware, and some of them even exceed the disposable PS tableware.

4. The preparation method of the present invention is dry hot press forming, and there is no pollution discharge in the production process, and the processing process is simple.

5. The product of the present invention is hot-pressed twice, and an exhaust and retraction process is provided between the two hot-presses, which has played a positive role in further improving the quality of the product and has achieved significant results.

6. After the disposable product of the present invention is used, it can be recovered and crushed to be processed into fish storage feed, and it can also be naturally degraded into organic fertilizer.

7. The present invention is rich in raw materials and relatively low in cost. Market competitiveness is an ideal substitute for replacing the existing plastic foam products. detailed description

The invention is further described below with reference to the drawings and embodiments:

Embodiment 1: A single-use fully degradable tableware (with a degradation period of 180 days or within 6 months) is manufactured according to the following formula and preparation process. The ingredients and weight percentages of the formula are:

Amino molding compound powder 40% by weight;

Corn flour 52.5% by weight;

Medium calcium carbonate powder 5% by weight;

Corn cob 2.5% by weight.

The preparation process is:

(1) Raw material pretreatment. Crush the corn cob to 120 mesh.

(2) Preparation of mix materials Weigh and mix each raw material powder according to the formula, and mix each raw material and stir well to obtain a mix.

(3), compression molding. The mixture is added to the initial pressure of the mold in the cavity, the mold is opened and vented once, and the mold is closed and hot-pressed to solidify. The unit pressure is 400 kg / cm ² , the temperature is 150 ° C, and the heat preservation and holding time is 50 seconds.

(4). Demoulding.

(5), trimming. Remove the burrs, and then polish the shape. If the model is a combination of multiple products, it must first be divided.

(6) Disinfection.

(7) Finished product packaging.

Complete degradation period: 6 months, temperature and water resistance: 95 ± 5 ° C oil and water, 45 minutes at 60 ° C constant temperature without shading and leakage. Embodiment 2: A single-use fully degradable medical disc (degradation period is 6 to 12 months) is manufactured according to the following formula and preparation process. The raw materials and weight percentages of the formula are: 50% by weight of amino molding compound powder;

37.5% weight of flour; 10% by weight of medium calcium carbonate powder;

Straw 2.5% weight.

The preparation process is:

(1) Raw material pretreatment. Crush the straw to 120 mesh.

(2) Preparation of mixture. Weigh each raw material powder according to the formula and mix each raw material and stir well to obtain a mixture.

(4). Demoulding.

(6) Disinfection.

(7) Finished product packaging.

The complete degradation period is 10 months. Temperature and water resistance: 95 ± 5 ° C oil and water, 60 minutes at 60 ° C constant temperature without shading and leakage. Embodiment 3: A single-use item package (degradation period is 6-12 months) is manufactured according to the following formula and preparation process. The raw materials and weight percentage of the formula are-50% by weight of amino molding compound powder;

20% by weight of legume powder;

Medium calcium carbonate powder 5% by weight;

Rice bran 22.5% by weight;

Water 2.5% by weight.

Preparation process is-

(1) Raw material pretreatment. The rice bran was pulverized to 120 mesh.

(2) Preparation of mixture. Weigh each raw material powder according to the formula, first mix the rice bran powder with water and stir well, then mix with the amino molding compound powder, legume powder, and medium calcium carbonate powder and stir to obtain a mixture.

(3), compression molding. Add the mixture into the mold cavity and close the initial pressure of the mold. The molds were hot-pressed and solidified again, and the unit pressure was 400 kg / cm ² , the temperature was 150 ° C, and the heat-preservation and pressure-maintaining curing time was 50 seconds.

(4). Demoulding.

(6), 'Disinfection.

(7) Finished product packaging.

The complete degradation period is 12 months. Temperature and water resistance: 95 ± 5 ° C oil and water, 80 minutes under 60 ° C constant temperature conditions, no shading and leakage. Examples 4-9

Following a method similar to Example 1, a single-use fully degraded tableware was prepared according to the following table:

% By weight Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Amino molding compound powder 36 44 55 44 55 45 Starch 58 47 33 42 18 22 Medium calcium carbonate powder 4 6 9 11 4 6 Rice bran 2 3 2 3 21 24 Water----2 3

Claims

Claim

1. A fully degradable material, which is characterized by containing the following components:

Amino molding compound 35 ~ 55% weight;

Starch 33 ~ 58% by weight;

Medium calcium carbonate 4 ~ 11% by weight;

Plant fiber material 2 ~ 3% by weight;

The plant fiber material is one of rice husk, crop straw, bagasse, corn cob, and peanut husk.

2. The fully degradable material according to claim 1, wherein the material contains the following components:

Amino molding compound 36 ~ 44% by weight;

47 ~ 58% starch

Medium calcium carbonate 4 ~ 6% weight;

Plant fiber material 2 ~ 3% by weight.

3. The fully degradable material according to claim 1, wherein the material contains the following components:

Amino molding compound 45 ~ 55% weight;

Starch 33 ~ 42% by weight;

Medium calcium carbonate 9 ~ 11% by weight;

Plant fiber material 2 ~ 3% by weight.

4. A fully degradable material, which is characterized by containing the following components

Amino molding compound 45 ~ 55% weight;

Starch 1 8 ~ 22% by weight;

Medium calcium carbonate 4 ~ 6% weight;

Plant fiber material 20 ~ 25% by weight;

Water 2 ~ 3% by weight;

5. Use of a fully degradable material according to any one of claims 1-4 in the preparation of disposable products.

6. A method for preparing a disposable article using a fully degradable material according to claim 1, comprising the following steps:

(1) Crush the plant fiber material to 100-200 mesh;

(2) Mix 35 ~ 55% by weight amino molding compound, 33 ~ 58% by weight starch, 4 ~ 11% by weight intermediate calcium carbonate, and 2 ~ 3% by weight plant fiber material to obtain a mixture;

120 ~ 18 (TC, 25 ~ 80 seconds for holding and holding pressure;

(5) The product is obtained by demolding and post-processing.

7. A method for preparing a disposable article using a fully degradable material according to claim 4, comprising the following steps:

(1) Crush the plant fiber material to 100-200 mesh;

(2) Mix 20 ~ 25% by weight of vegetable fiber material with 2 ~ 3% by weight of water, and then mix with 45 ~ 55% by weight of amino molding compound, 18 ~ 22% by weight of starch and 4 ~ 6% by weight of medium carbonic acid. Calcium is mixed to obtain a mixture;

(4) Re-molding and hot-pressing and curing, the unit pressure is 300 ~ 450kg / cm ² , the temperature is 120 ~ 180 ° C, and the heat-preserving and curing time is 25 ~ 80 seconds;

(5) The product is obtained by demolding and post-processing. .

8. The method according to claim 6 or 7, characterized in that the post-processing mainly comprises trimming and disinfection.

9. The method according to claim 6 or 7, characterized in that the particle size of the amino molding compound, starch and medium calcium carbonate is above 140 mesh.