CN110746648A - Preparation method of modified white carbon black for nylon 6 - Google Patents
Preparation method of modified white carbon black for nylon 6 Download PDFInfo
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- CN110746648A CN110746648A CN201911055163.9A CN201911055163A CN110746648A CN 110746648 A CN110746648 A CN 110746648A CN 201911055163 A CN201911055163 A CN 201911055163A CN 110746648 A CN110746648 A CN 110746648A
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K9/00—Use of pretreated ingredients
- C08K9/08—Ingredients agglomerated by treatment with a binding agent
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
- C08G69/02—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids
- C08G69/08—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from amino-carboxylic acids
- C08G69/14—Lactams
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K7/00—Use of ingredients characterised by shape
- C08K7/22—Expanded, porous or hollow particles
- C08K7/24—Expanded, porous or hollow particles inorganic
- C08K7/26—Silicon- containing compounds
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K9/00—Use of pretreated ingredients
- C08K9/04—Ingredients treated with organic substances
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K9/00—Use of pretreated ingredients
- C08K9/04—Ingredients treated with organic substances
- C08K9/06—Ingredients treated with organic substances with silicon-containing compounds
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers
- C08L77/02—Polyamides derived from omega-amino carboxylic acids or from lactams thereof
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/28—Compounds of silicon
- C09C1/30—Silicic acid
- C09C1/3063—Treatment with low-molecular organic compounds
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/28—Compounds of silicon
- C09C1/30—Silicic acid
- C09C1/3081—Treatment with organo-silicon compounds
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/28—Compounds of silicon
- C09C1/30—Silicic acid
- C09C1/309—Combinations of treatments provided for in groups C09C1/3009 - C09C1/3081
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- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/22—Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K2201/00—Specific properties of additives
- C08K2201/002—Physical properties
- C08K2201/003—Additives being defined by their diameter
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- Compositions Of Macromolecular Compounds (AREA)
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Abstract
The invention discloses a preparation method of modified white carbon black for nylon 6, which comprises the following steps: 1) adding an initiator, a catalyst and a molecular weight regulator into caprolactam, and reacting for 0.5-24 h at 80-160 ℃ under the protection of nitrogen to obtain caprolactam oligomer; the addition amounts of the initiator, the catalyst and the molecular weight regulator are respectively 0.1-5%, 0.2-8% and 0.5-10% of the mass of caprolactam; 2) preparing white carbon black slurry with the mass concentration of 5-25%; 3) heating the white carbon black slurry to 50-100 ℃, adding caprolactam oligomer, stirring and reacting for 0.5-2 h, adding an organic coupling agent, stirring and emulsifying for 0.5-1.5 h, filtering, drying and crushing to obtain the modified white carbon black. The preparation method is simple and low in cost, a volatile solvent is not adopted in the preparation process, the environmental pollution is small, the prepared modified white carbon black has good dispersibility in nylon 6, and the tensile strength, toughness and modulus of the nylon 6 can be improved.
Description
Technical Field
The invention belongs to the technical field of preparation of white carbon black, and particularly relates to a preparation method of modified white carbon black for nylon 6.
Background
The white carbon black has the characteristics of large specific surface area, small particle size, good chemical stability, high temperature resistance, good electrical insulation performance and the like, is widely applied to industries such as rubber, tires, adhesives, coatings, plastics and the like, but has a large amount of active silicon hydroxyl on the surface, is easy to absorb water and aggregate into particles, causes poor compatibility and dispersibility in a high polymer matrix, and is limited in some application fields with functional requirements. Therefore, the white carbon black can be modified according to different requirements.
Nylon is a thermoplastic engineering plastic widely used in various fields, and has excellent properties such as high strength, wear resistance, impact resistance, fatigue resistance, corrosion resistance, oil resistance and the like, but nylon 6 has the defects of poor low-temperature and dry impact properties, high water absorption and the like. In order to meet the needs of industrial development, improvement of properties such as dry impact property and water absorption of nylon 6 has become a subject of extensive attention. In addition, in many application fields, the toughness of the nylon is highly required, so that the toughening modification of the nylon has important theoretical and practical significance.
The Chinese patent publication No. CN101215416A is that silicon dioxide is dispersed in polar organic solvent, and through in-situ polymerization to prepare master batch, and then the master batch is melt blended with polycaprolactam to prepare the nano silicon dioxide/polycaprolactam composite resin. However, the above invention has the disadvantages of high polymerization temperature, high energy consumption, high cost, complicated process, etc.
Disclosure of Invention
The invention aims to provide a preparation method of modified white carbon black for nylon 6
Based on the purpose, the invention adopts the following technical scheme:
a preparation method of modified white carbon black for nylon 6 comprises the following steps:
1) adding an initiator, a catalyst and a molecular weight regulator into caprolactam, and reacting for 0.5-24 h at 80-160 ℃ under the protection of nitrogen to obtain caprolactam oligomer; the addition amounts of the initiator, the catalyst and the molecular weight regulator are respectively 0.1-5%, 0.2-8% and 0.5-10% of the mass of caprolactam;
2) dispersing a certain amount of white carbon black in water to prepare white carbon black slurry with the mass concentration of 5-25%;
3) heating the white carbon black slurry obtained in the step 2) to 50-100 ℃, adding the caprolactam oligomer obtained in the step 1), stirring and reacting for 0.5-2 hours, adding the organic coupling agent, stirring and emulsifying for 0.5-1.5 hours, filtering, drying and crushing to obtain modified white carbon black; the mass ratio of the caprolactam oligomer to the white carbon black is 1: 1-20.
In the step 1), the initiator is one or a mixture of more than two of water, ethanol and glycol.
The catalyst in the step 1) is one or a mixture of concentrated sulfuric acid and concentrated nitric acid.
The molecular weight regulator in the step 1) is one or a mixture of more than two of caproic acid, acetic acid and adipic acid.
The organic coupling agent in the step 3) is one or a mixture of more than two of silane coupling agent, borate coupling agent, titanate coupling agent and aluminate coupling agent.
The organic coupling agent is a silane coupling agent.
The addition amount of the organic coupling agent is 0.5-10% of the mass of the white carbon black.
The particle size of the white carbon black in the step 2) is 10-100 nm.
Compared with the prior art, the invention has the following beneficial effects:
the preparation method is simple and low in cost, a volatile solvent is not adopted in the preparation process, the environmental pollution is small, the prepared modified white carbon black has good dispersibility in nylon 6, and the tensile strength, toughness and modulus of the nylon 6 can be improved.
Detailed Description
Example 1
A preparation method of modified white carbon black for nylon 6 comprises the following steps:
1) adding 100g of caprolactam, 1g of water, 2g of concentrated sulfuric acid and 2.25g of adipic acid into a three-neck flask, heating to 110 ℃ under the protection of nitrogen, and reacting for 3 hours (until the product becomes viscous) to obtain caprolactam oligomer;
2) dispersing 500g of untreated white carbon black with the particle size of 15nm in water to prepare white carbon black slurry with the mass concentration of 15%;
3) heating the white carbon black slurry obtained in the step 2) to 60 ℃, adding the caprolactam oligomer obtained in the step 1), adjusting the temperature to 60 ℃, stirring at the rotating speed of 100 rpm, reacting for 1.5h, adding 20g of silane coupling agent, continuously stirring and emulsifying for 1h, filtering, drying and crushing to obtain the modified white carbon black.
Example 2
A preparation method of modified white carbon black for nylon 6 comprises the following steps:
1) adding 200g of caprolactam, 10g of absolute ethyl alcohol, 1g of concentrated nitric acid and 5g of acetic acid into a three-neck flask, and reacting for 6 hours (until the product becomes viscous) at 150 ℃ under the protection of nitrogen to obtain caprolactam oligomer;
2) dispersing 2000g of white carbon black with the particle size of 20nm in water to prepare white carbon black slurry with the mass concentration of 10%;
3) heating the white carbon black slurry obtained in the step 2) to 70 ℃, adding the caprolactam oligomer obtained in the step 1), adjusting the temperature to 70 ℃, stirring at the rotating speed of 300 r/min, reacting for 1h, adding 50g of borate coupling agent, continuously stirring and emulsifying for 1h, filtering, drying and crushing to obtain the modified white carbon black.
Example 3
A preparation method of modified white carbon black for nylon 6 comprises the following steps:
1) adding 120g of caprolactam, 2g of ethylene glycol, 5g of concentrated sulfuric acid and 3.5g of acetic acid into a three-neck flask, heating to 90 ℃ under the protection of nitrogen, and reacting for 8 hours (until the product becomes viscous) to obtain caprolactam oligomer;
2) dispersing 900g of untreated white carbon black with the particle size of 25nm in water to prepare white carbon black slurry with the mass concentration of 20%;
3) heating the white carbon black slurry obtained in the step 2) to 80 ℃, adding the caprolactam oligomer obtained in the step 1), adjusting the temperature to 80 ℃, stirring at the rotating speed of 200 rpm, reacting for 1 hour, adding 20g of silane coupling agent, continuously stirring and emulsifying for 1 hour, filtering, drying and crushing to obtain the modified white carbon black.
Example 4
1000g of untreated white carbon having a particle diameter of 12nm were directly used as comparative example 1.
Performance testing
The properties of the modified white carbon black of examples 1 to 3 and the white carbon black of comparative example 1 were measured. The test results are shown in table 1.
TABLE 1 results of mechanical Properties test of examples and comparative examples
As shown in table 1, the modified white carbon black of the present invention has improved tensile strength, elongation at break, flexural strength, and notched impact strength to a great extent, and thus can improve the tensile strength, toughness, and modulus of nylon 6, as compared to comparative example 1.
Claims (8)
1. The preparation method of the modified white carbon black for nylon 6 is characterized by comprising the following steps:
1) adding an initiator, a catalyst and a molecular weight regulator into caprolactam, and reacting for 0.5-24 h at 80-160 ℃ under the protection of nitrogen to obtain caprolactam oligomer; the addition amounts of the initiator, the catalyst and the molecular weight regulator are respectively 0.1-5%, 0.2-8% and 0.5-10% of the mass of caprolactam;
2) dispersing a certain amount of white carbon black in water to prepare white carbon black slurry with the mass concentration of 5-25%;
3) heating the white carbon black slurry obtained in the step 2) to 50-100 ℃, adding the caprolactam oligomer obtained in the step 1), stirring and reacting for 0.5-2 hours, adding the organic coupling agent, stirring and emulsifying for 0.5-1.5 hours, filtering, drying and crushing to obtain modified white carbon black; the mass ratio of the caprolactam oligomer to the white carbon black is 1: 1-20.
2. The method for preparing modified white carbon black for nylon 6 according to claim 1, wherein the initiator in the step 1) is one or a mixture of more than two of water, ethanol and ethylene glycol.
3. The method for preparing modified silica white for nylon 6 according to claim 2, wherein the catalyst in step 1) is one or a mixture of concentrated sulfuric acid and concentrated nitric acid.
4. The method for preparing modified silica white for nylon 6 according to claim 3, wherein the molecular weight regulator in step 1) is one or a mixture of more than two of caproic acid, acetic acid and adipic acid.
5. The method for preparing modified silica white for nylon 6 according to claim 1, wherein the organic coupling agent in step 3) is one or a mixture of two or more of silane coupling agent, borate coupling agent, titanate coupling agent and aluminate coupling agent.
6. The method for preparing modified white carbon black for nylon 6 according to claim 5, wherein the organic coupling agent is a silane coupling agent.
7. The preparation method of the modified white carbon black for nylon 6, according to claim 6, wherein the addition amount of the organic coupling agent is 0.5-10% of the mass of the white carbon black.
8. The method for preparing modified white carbon black for nylon 6 according to any one of claims 1 to 7, wherein the particle size of the white carbon black in the step 2) is 10 to 100 nm.
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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CN116003780A (en) * | 2023-01-09 | 2023-04-25 | 华润化学材料科技股份有限公司 | Nylon engineering plastic and preparation method thereof |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102951649A (en) * | 2012-11-15 | 2013-03-06 | 北京橡胶工业研究设计院 | Preparation method of modified precipitated white carbon black |
US20130131357A1 (en) * | 2011-06-02 | 2013-05-23 | Beijing University Of Chemical Technology | Method for preparing white carbon black modified by silane coupling agent |
CN103237832A (en) * | 2010-10-07 | 2013-08-07 | 巴斯夫欧洲公司 | Method for producing monomer composition, and use thereof for producing molded polyamide part |
CN107011509A (en) * | 2017-04-28 | 2017-08-04 | 湖南工业大学 | A kind of heat conduction powder/monomer moulding casting nylon nano composite material and its preparation method and application |
CN107973935A (en) * | 2017-12-07 | 2018-05-01 | 沈阳化工大学 | A kind of modified white carbon black and preparation method thereof |
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Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103237832A (en) * | 2010-10-07 | 2013-08-07 | 巴斯夫欧洲公司 | Method for producing monomer composition, and use thereof for producing molded polyamide part |
US20130131357A1 (en) * | 2011-06-02 | 2013-05-23 | Beijing University Of Chemical Technology | Method for preparing white carbon black modified by silane coupling agent |
CN102951649A (en) * | 2012-11-15 | 2013-03-06 | 北京橡胶工业研究设计院 | Preparation method of modified precipitated white carbon black |
CN107011509A (en) * | 2017-04-28 | 2017-08-04 | 湖南工业大学 | A kind of heat conduction powder/monomer moulding casting nylon nano composite material and its preparation method and application |
CN107973935A (en) * | 2017-12-07 | 2018-05-01 | 沈阳化工大学 | A kind of modified white carbon black and preparation method thereof |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN116003780A (en) * | 2023-01-09 | 2023-04-25 | 华润化学材料科技股份有限公司 | Nylon engineering plastic and preparation method thereof |
CN116003780B (en) * | 2023-01-09 | 2024-06-07 | 华润化学材料科技股份有限公司 | Nylon engineering plastic and preparation method thereof |
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