Anti-pre-crosslinking rapid-solidification low-smoke zero-halogen flame-retardant silane crosslinking nano-modified polyolefin composition

Abstract

The invention relates to an anti-pre-crosslinking rapid-solidification low-smoke zero-halogen flame-retardant silane crosslinking nano-modified polyolefin composition. The composition is prepared from, by weight, 100 parts of zero-halogen flame-retardant silane grafted nano-modified polyolefin matrixes A and 4-6 parts of catalyst master batches B. By the adoption of a fractional step method, a preparation method includes the steps that the zero-halogen flame-retardant silane grafted nano-modified polyolefin matrixes A and the catalyst master batches B are prepared and then mixed evenly, wherein the zero-halogen flame-retardant silane grafted nano-modified polyolefin matrixes A are formed by mixing nano-modified polyolefin, zero-halogen flame-retardant master batches, a silane grafted system and anti-pre-crosslinking agents, and the catalyst master batches B are formed by mixing carrier resin polyolefin and a rapid catalyst system. By the application of the method, the anti-pre-crosslinking low-smoke zero-halogen flame-retardant silane crosslinking nano-modified polyolefin composition capable of achieving rapid crosslinking under natural conditions can be prepared, the performance of the composition meets using requirements, and particularly, the composition can also be used for producing heat-resistant flame-retardant pipes when serving as a low-smoke zero-halogen flame-retardant silane crosslinking polyolefin cable material.

Description

technical field [0001] The present invention relates to an anti-pre-crosslinking fast-curing low-smoke halogen-free flame-retardant silane cross-linked nano-modified polyolefin composition and its preparation process, in particular to an anti-pre-crosslinking in the preparation process and storage, A low-smoke, halogen-free, flame-retardant silane cross-linked nano-modified polyolefin cable material that can be rapidly cross-linked under natural conditions after being extruded into a product and a preparation method thereof. The composition is mainly used in the insulation coating production of low-voltage (below 10KV) wires and cables with environmental protection and flame-retardant requirements, and can also be used in the production of flame-retardant pipes and the like. Background technique [0002] Cross-linked low-smoke, halogen-free, and flame-retardant polyolefin compositions for wire and cable are currently mainly manufactured in China by irradiation cross-linking ...

AI Technical Summary

Problems solved by technology

The silane crosslinkability of the base resin used in this method is not good, and the adsorption of silane by the granular carrier resin is not ideal

Chinese invention patent CN103205051A: In the low-smoke halogen-free flame-retardant silane polyolefin and its preparation method, the base resin silane is grafted first, and then the halogen-free flame-retardant masterbatch with high flame retardant content is twin-screw extrusion pelletized, silane The fluidity of the grafted resin decreases, and when it is co-extruded with a flame retardant containing a high proportion of crystal water, pre-crosslinking reactions are prone to occur. As the main flame retardant, the flame retardant will cause pre-crosslinking during product storage due to its strong moisture absorption, and will lead to a rapid decline in the electrical properties of the crosslinked product

In the Chinese patent CN103013020A silane natural cross-linked low-smoke halogen-free flame-retardant polyolefin cable material and its preparation method, the basic resin silane is first grafted with high-content halogen-free flame-retardant masterbatch twin-screw extrusion pelletization; although Modified montmorillonite is used as a flame retardant synergist to reduce the amount of the main flame retardant, which can improve the processing fluidity of the product and reduce the cost, but the method is to compound the silane grafting material with the flame retardant Mixed with modified nano-montmorillonite, etc., it is difficult to make nano-montmorillonite form an intercalation or exfoliation structure, and no effective synergistic flame retardant effect can be achieved, and in this invention, hydrogen oxidation with a lower decomposition temperature is used. Aluminum, during the extrusion preparation process, is prone to premature decomposition to release crystal water, causing pre-crosslinking

Chinese patent CN102558733A: silane cross-linked low-smoke halogen-free flame-retardant polyolefin and Chinese patent CN101245169B: non-boiled low-smoke halogen-free flame-retardant silane cross-linked polyolefin composition and its preparation method, both adopt one-step method, although the preparation process is simple , but the reaction of the silane grafted resin should be completed when extruding the cross-linked product, the grafting reaction equipment and process conditions are high, and it is difficult for the single-screw extruder used to extrude the product to complete the reaction step stably

When using a twin-screw extruder to extrude and granulate a flame-retardant polyolefin material with a large amount of inorganic hydroxide flame retardant powder, the uniform feeding of the extruder and the full mixing and uniformity of the components are very important. Difficulty; This invention also has the problem that the reaction of silane grafted resin will be difficult to control when extruding the cross-linked product

Chinese patent CN103261324 applied by American Dow Global Company: Halogen-free flame retardant compound containing cross-linked silane-g-EVA, which involves thermoplastic polyurethane composite materials, and the organic phosphate flame retardant used is highly volatile and heat-resistant Low temperature, with obvious neurotoxicity, carcinogenicity and genotoxicity, posing a potential threat to the ecological environment and human health

Chinese patent CN103224681A: In the silane self-crosslinking halogen-free flame-retardant polyolefin foam composite material and its preparation method, an intumescent phosphorus-nitrogen flame retardant is used as the main flame retardant. Although the addition amount can be low, this type of Flame retardants tend to absorb moisture and water, leading to pre-crosslinking

Japanese patent JP-A-3-167229 discloses a one-step silane crosslinking method, which uses a porous polymer as a carrier resin. In this method, in addition to silane and free radical initiators, the carrier polymer A cross-linking catalyst should also be added in the storage process. During the storage process, the catalyst will cause the oligomerization of silane, which will affect the cross-linking effect in the next step.

[0004] In short, although the current methods for preparing flame-retardant cross-linked polyolefin materials omit the complicated link of irradiation, the cross-linking speed is slow under natural conditions, and basically all need boiling or steam bath to speed up the cross-linking process, which is time-consuming. performance, seriously affecting economic benefits; and the use of halogen-free flame retardants, especially inorganic hydroxides, is added in a large amount, which reduces the processing fluidity of the product, and most of the flame retardants contain crystal water or are easy to absorb moisture and water. It is very easy to cause pre-crosslinking of silane grafts during the manufacturing process, which seriously affects the subsequent production and processing performance and product quality of the product, and even leads to the scrapping of the product

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