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CN-118290933-B - Melamine standard substance based on polyamide substrate and preparation method and application thereof

CN118290933BCN 118290933 BCN118290933 BCN 118290933BCN-118290933-B

Abstract

The invention discloses a melamine standard substance based on a polyamide substrate, and a preparation method and application thereof, and belongs to the technical field of standard substance preparation. The melamine standard substance provided by the invention comprises 89-99 parts by weight of polyamide resin, 1-10 parts by weight of melamine cyanurate, 0.05-0.35 part by weight of antioxidant and 0.1-1.1 part by weight of lubricant, wherein the relative viscosity of the polyamide resin is less than or equal to 2.55, the antioxidant is at least one of phosphite antioxidant and hindered phenol antioxidant, the lubricant is polyethylene wax, and the apparent viscosity of the polyethylene wax at 140 ℃ is 550-660cps. The melamine content in the melamine standard substance provided by the invention has excellent stability within the range of 300-1000mg/kg, and the obtained standard substance has no obvious difference between the inside and the outside of the sample.

Inventors

  • LI WEILING
  • YE NANBIAO
  • WU BO
  • RAO XIANG
  • PANG CHENGHUAN
  • CHEN PINGXU
  • LI JIANJUN
  • ZHOU HUALONG

Assignees

  • 国高材高分子材料产业创新中心有限公司
  • 金发科技股份有限公司

Dates

Publication Date
20260505
Application Date
20240318

Claims (8)

  1. 1. A melamine standard based on a polyamide substrate, characterized in that it comprises the following components in parts by weight: 89-99 parts of polyamide resin, 1-10 parts of melamine cyanurate, 0.05-0.35 part of antioxidant and 0.1-1.1 part of lubricant; the relative viscosity of the polyamide resin is less than or equal to 2.55, the relative viscosity of the polyamide resin is tested by referring to ISO 307-2019, the relative viscosity is tested by weighing 0.5g of the polyamide resin, transferring the polyamide resin into a 50 mL volumetric flask, adding 40 mL of 96% mass fraction concentrated sulfuric acid, oscillating by ultrasonic until the polyamide resin is completely dissolved, cooling the solution to 25 ℃, diluting the solution to a scale by using the concentrated sulfuric acid, mixing uniformly, and recording the flow-through time of 0.01g/mL of the polyamide resin solution through an Ubbelohde viscometer at the temperature of 25 ℃, namely t1, the flow-through time of the solvent concentrated sulfuric acid is tested by using the same viscometer, namely t2, and t1/t2 is the relative viscosity; the antioxidant is at least one of phosphite antioxidants and hindered phenol antioxidants; The lubricant is polyethylene wax, the apparent viscosity of the polyethylene wax at 140 ℃ is 550-660 cps, and the apparent viscosity of the polyethylene wax at 140 ℃ is tested by referring to ASTM D1986-14.
  2. 2. The melamine standard according to claim 1, wherein the polyamide resin is at least one of polyamide 6 and polyamide 66.
  3. 3. Melamine standard according to claim 1, characterized in that the polyamide resin has a relative viscosity of 1.65-2.45.
  4. 4. The melamine standard according to claim 1, wherein the antioxidant is at least one of antioxidant 168, antioxidant 608, antioxidant PEP 36.
  5. 5. The melamine standard according to claim 1, wherein the apparent viscosity of the polyethylene wax is 570-580cps at 140 ℃.
  6. 6. The method for preparing the melamine standard according to any one of claims 1 to 5, comprising the steps of uniformly mixing the components, melt-extruding, and granulating to obtain the melamine standard.
  7. 7. The method according to claim 6, wherein the melt extrusion temperature is 190-250 ℃ and the rotation speed is 250-350rpm.
  8. 8. Use of a melamine standard according to any one of claims 1-5 for evaluating the amount of melamine migration in plastic materials.

Description

Melamine standard substance based on polyamide substrate and preparation method and application thereof Technical Field The invention relates to the technical field of standard substance preparation, in particular to a melamine standard substance based on a polyamide substrate, and a preparation method and application thereof. Background Food contact materials refer to various materials that are in direct contact with or possibly in contact with food, the safety of which is critical to ensuring food quality and human health. An increasing number of plastic articles are used in the food packaging industry, wherein melamine in plastic articles is one of the common contaminants in food contact materials, and can migrate from the plastic material into the food, creating a potential risk to human health. The development of the existing standard substances of the melamine based on the plastic in the food contact material is mostly concentrated on the liquid such as dairy powder, methanol/water and the like, but the standard substances of the plastic base material are relatively few, and because the plastic material structure is a condensed structure, the migration rule of the melamine is greatly different from the conventional liquid and powder forms, and the situation limits the accurate assessment and control of the migration of the melamine in the plastic base material. In addition, the european chemical authorities list highly focused substances for melamine, and the management and control of melamine substances in the current electronic and electrical fields are also in the list, and most of the current electronic and electrical fields are plastic materials, so that the traditional dairy products and liquid melamine standard substances have different forms and control limit values, and cannot meet the requirements for the management and control of melamine in the electronic and electrical fields, and development of melamine standard substances based on plastic substrates is urgently needed. Patent CN109883782a discloses a standard substance of milk powder containing melamine and a preparation method, which adopts melamine and milk powder to be respectively dissolved and then mixed to prepare a uniform solution, and then the solution is dried and crushed to obtain the standard substance, but the method is to directly add melamine into the milk powder and belongs to the food field, and can not be effectively applied to the research of melamine rules in plastics in the electronic and electric field. Patent CN1233711C discloses a molecular composite melamine cyanurate flame retardant and a preparation method thereof, focuses on researching the preparation method of the melamine cyanurate flame retardant, does not relate to the research of melamine standard substances in polymer materials, and patent CN111040248A discloses a preparation method of Melamine Cyanurate (MCA) flame retardant and application thereof in PA6, focuses on researching and reporting the preparation method of the flame retardant and application thereof in PA6 as the flame retardant, and does not relate to the research of uniform and stable standard substances and the research of the accurate content of melamine. Therefore, the above-mentioned published literature data focus on research on melamine standard substances in foods and research on preparation and flame-retardant application of melamine cyanurate flame retardants, and have not been reported on the research on melamine standard substances in plastic substrates. The prior art still has some problems and limitations in the development of melamine standard substances for plastic substrates in the field of electronics and electrical, and needs to be further improved and perfected. Disclosure of Invention Based on the defects existing in the prior art, the invention aims to provide a melamine standard substance with excellent stability and based on a polyamide substrate, and a preparation method and application thereof. In order to achieve the above object, in a first aspect of the present invention, there is provided a melamine standard substance based on a polyamide substrate, the melamine standard substance comprising the following components, by weight, 89-99 parts of a polyamide resin, 1-10 parts of melamine cyanurate, 0.05-0.35 part of an antioxidant, and 0.1-1.1 parts of a lubricant; The relative viscosity of the polyamide resin is less than or equal to 2.55; the antioxidant is at least one of phosphite antioxidants and hindered phenol antioxidants; The lubricant is polyethylene wax with apparent viscosity of 550-660cps at 140 ℃. According to the melamine standard substance based on the polyamide substrate, the melamine content in the obtained melamine standard substance is excellent in stability within the range of 300-1000mg/kg by selecting proper parts by mass of components and types of the components, and no obvious difference exists between the inside and the outside of the sa