CN110951167B

CN110951167B - Transparent polypropylene resin with optical lighting haze and preparation method thereof

Info

Publication number: CN110951167B
Application number: CN201911226760.3A
Authority: CN
Inventors: 娄小安; 李莉; 陈超; 陈光伟; 梁伟成; 陈晓东
Original assignee: Shanghai Sunny Technology Co ltd
Current assignee: Shanghai Sunny Technology Co ltd
Priority date: 2019-12-04
Filing date: 2019-12-04
Publication date: 2022-04-15
Anticipated expiration: 2039-12-04
Also published as: CN110951167A

Abstract

The invention relates to a transparent polypropylene resin with optical lighting haze and a preparation method thereof, wherein the transparent polypropylene resin with optical lighting haze mainly comprises 100 parts by weight of polypropylene, 0.5-1 part by weight of compound nucleating agent, 0.6-0.8 part by weight of atomizing agent, 7-9 parts by weight of anti-aging component and 2-3 parts by weight of polar modifier, wherein the atomizing agent is sodium polyacrylate resin with a porous structure; the preparation method comprises the following steps: the components are mixed according to the formula ratio and then are melted and extruded to prepare the transparent polypropylene resin with optical lighting haze. The invention utilizes the characteristics of the sodium polyacrylate resin with porous structure that the sodium polyacrylate resin absorbs water to become transparent and dehydrates and is not transparent to prepare the polypropylene resin with optical lighting haze; the high-transparency polypropylene resin is prepared by selecting a proper compound nucleating agent; by selecting proper anti-aging components, the polypropylene resin with excellent thermo-oxidative aging resistance is prepared. The method of the invention has simple operation and low cost.

Description

Transparent polypropylene resin with optical lighting haze and preparation method thereof

Technical Field

The invention belongs to the technical field of polypropylene composite materials, and relates to a transparent polypropylene resin with optical lighting haze and a preparation method thereof.

Background

With the rapid development of the modern home decoration industry, the requirements of people on individuation and functionalization of home decoration products are higher and higher, and new requirements are provided in the field of lamps. For example, the transparent reversible conversion optical glass for lighting up, fogging and light-out in the market at present adopts electric control liquid crystal glass, and specifically comprises the following components: the liquid crystal film is packaged between the transparent glasses in a high-temperature and high-pressure mode, and a user can control the arrangement of liquid crystal molecules according to the electrification of current or not, so that the aim of controlling the transparent and opaque states of the glass is fulfilled.

With the technical innovation of the field of LED lamps, the plastic lampshade gradually enters the market and partially replaces the original glass lampshade. The plastic material has the advantages of low raw material cost, good material toughness, light weight, difficult damage, low processing energy consumption, wide processing window and the like. The PC material has been widely used in LED lamp covers in various fields instead of glass material because of its excellent properties, especially material transparency.

However, due to the shortage of PC raw material sources and the high price of raw materials, especially the trend of mountain bike type price rising since 2018, serious innovation is caused to downstream lamp enterprises, some PC materials for plugging and LED light diffusion PC materials have been turned to polypropylene (PP) materials, PP is adopted to replace the traditional PC material for the field of LED lamps, the raw material cost can be reduced by 40% for downstream lamp customers, compared with PC resin, the PP has the obvious advantage that the processing window of the material is wide, but PP is a polymer easy to crystallize, the transparency of unmodified or conventionally crystal-modified PP is far less excellent than PC, and the two technical problems are inferior to PC in thermal oxidation resistance and aging resistance, which severely limit the application of PP materials in the optical field.

In addition, neither PC material nor PP material has the characteristics of transparent and reversible conversion between lighting and fogging and lighting-out, which hinders the popularization of plastic lampshades to some extent.

Therefore, it is very important to study a polypropylene resin having optical lighting haze (i.e., lighting fogging and light extinction transparency), high transparency, and excellent thermal oxidative aging resistance.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a transparent polypropylene resin with optical lighting haze and a preparation method thereof.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the transparent polypropylene resin with optical lighting haze comprises polypropylene, an atomizing agent, a polar modifier and a compound nucleating agent, wherein the atomizing agent is sodium polyacrylate resin with a porous structure, and the compound nucleating agent consists of a beta nucleating agent and an alpha nucleating agent.

One of the objectives of the present invention is to solve the problem that the polypropylene resin in the prior art does not have optical lighting haze, and specifically, to solve the problem by mixing polypropylene, an atomizing agent (a sodium polyacrylate resin with a porous structure), and a polar modifier, the specific mechanism is as follows:

the sodium polyacrylate resin with the porous structure has the properties of becoming transparent after absorbing water and being opaque after dehydration, the polypropylene is a nonpolar polymer and incompatible with water, so the water absorption rate is low, after a polar modifier is introduced into the polypropylene, the water absorption rate is greatly improved, when a lamp is turned off, the polypropylene can absorb moisture in the air and transmit the moisture to the sodium polyacrylate resin in the polypropylene under the action of the polar modifier, and the sodium polyacrylate resin becomes transparent after absorbing water, so that the polypropylene becomes transparent; when lighting, heat is transferred to the sodium polyacrylate resin through the polypropylene, the sodium polyacrylate resin is dehydrated and changed from a transparent state to an opaque state, and the polypropylene is further opaque (i.e. fogging).

As a preferred technical scheme:

the transparent polypropylene resin with optical lighting haze mainly comprises, by weight, 100 parts of polypropylene, 0.5-1 part of a compound nucleating agent, 0.6-0.8 part of an atomizing agent (the addition amount of the atomizing agent is too much to influence the transparency during light-off and the optical haze during lighting is too little to influence the lighting), 7-9 parts of an anti-aging component and 2-3 parts of a polarity modifier.

The polypropylene is a random copolymerization polypropylene, the anti-aging component is composed of an antioxidant and a heat conducting agent, the polarity modifier is composed of PP-g-MAH and polyvinyl alcohol, when the polypropylene resin is heated and blended, hydroxyl on the polyvinyl alcohol chain randomly reacts with anhydride in the PP-g-MAH, so that polypropylene branched chains are grafted on the polyvinyl alcohol chain to form a new molecular chain (intermediate product), the polypropylene branched chains in the intermediate product are similar to and compatible with the polypropylene chain, the compatibility and the movement of the molecular chain form a chain entanglement structure between the polypropylene branched chains, and the chain entanglement further enables rich hydroxyl of the polyvinyl alcohol to be well distributed around the polypropylene chain, so that the hydrophilicity of the polypropylene is improved.

In the transparent polypropylene resin with optical lighting haze, MI of the random copolymerization polypropylene is 22-25 g/10min, and is not suitable to be too high, otherwise, the molecular chain is too short, and the mechanical property of the prepared product is not good.

In the transparent polypropylene resin having optical lighting haze, the mass ratio of the beta nucleating agent to the alpha nucleating agent is 5: 2.

The transparent polypropylene resin with optical lighting haze comprises 1: 8-10 mass ratio of the antioxidant to the heat conducting agent, BASF 168 as the antioxidant, and 240-250 ℃ high-temperature resistant heat conducting silicone oil as the heat conducting agent.

According to the transparent polypropylene resin with optical lighting haze, the mass ratio of PP-g-MAH to polyvinyl alcohol is 1: 5-7, when the mass ratio of PP-g-MAH to polyvinyl alcohol is too small, the reaction points of hydroxyl and anhydride are too many, so that the viscosity of the system is increased, MI of the whole system is seriously influenced, the polypropylene crystallization is slowed, the nucleation points of spherulites are relatively reduced, the spherulites are not refined enough, and the transparency of a product is reduced; when the mass ratio of PP-g-MAH to polyvinyl alcohol is too large, the intermediate product is too small, and the hydrophilicity of the polypropylene is not sufficiently improved.

The transparent polypropylene resin with optical lighting haze, which has the thickness of 2.0mm, has the light transmittance of 88-92% when not lighting, the haze when lighting is 92-98%, the light transmittance reduction rate after lighting for 1500h under the temperature condition of 150 ℃ is less than 2%, and the haze variation value after lighting for 1500h at 150 ℃ is less than 1%.

The invention also aims to solve the problem of low transparency of the polypropylene resin in the prior art, and mainly solves the problem by selecting proper polypropylene, selecting proper compound nucleating agent and dosage and the like, and the specific mechanism is as follows:

the polypropylene is random copolymerization polypropylene with MI of 22-25 g/10min, and the molecular chain has stronger motion capability, so that amorphous form can be obtained, and higher transparency can be obtained;

the compound nucleating agent consists of a beta nucleating agent and an alpha nucleating agent, wherein the alpha nucleating agent plays a role in providing a rapid nucleation point, polypropylene can form a large amount of spherulites in the presence of the alpha nucleating agent, and the beta nucleating agent plays a role in changing the growth state of the spherulites by forming mixed crystals; the mass ratio of the beta nucleating agent to the alpha nucleating agent is 5:2, wherein when the proportion of the alpha nucleating agent is too large, the beta nucleating agent is difficult to change the growth state of spherulites; when the occupation ratio of the alpha nucleating agent is too small, the number of nucleation points is reduced, and the polypropylene chain segments grow more grains; the proper mass ratio of the beta nucleating agent to the alpha nucleating agent is beneficial to grain refinement, and the grain refinement can improve the transparency of the polypropylene;

the addition amount of the compound nucleating agent is proper, the crystal grain refinement is not enough when the addition amount is too low, and the transparency can not meet the requirement of improvement; too high, the effect is not improved, but the cost is increased;

the random copolymerization polypropylene with MI of 22-25 g/10min is matched with the compound nucleating agent, so that the grain growth capacity and speed of each nucleation point are improved, finer grains are obtained, and the transparency of the polypropylene is improved.

The invention also aims to solve the problem of poor thermal-oxidative aging resistance of the polypropylene resin in the prior art, and mainly solves the problem by adding anti-aging components (an antioxidant and a heat-conducting agent, wherein the antioxidant is BASF 168, and the heat-conducting agent is heat-conducting silicone oil resistant to high temperature of 240-250 ℃), and the specific mechanism is as follows:

the polypropylene can be degraded and generate free radicals in use, and the antioxidant plays a role in capturing the free radicals; the heat conducting agent reduces the local temperature of the polypropylene generated by heat absorption due to illumination, and further prevents the polypropylene from being aged by local heating. The antioxidant and the heat conducting agent play a mutual promotion role, and specifically comprise the following components: when the polypropylene product is produced, the heat-conducting agent can form a protective layer on the surface of the product, and the protective layer can isolate the polypropylene from contacting with oxygen and reduce the heat accumulation; in addition, the heat conducting agent has self-lubricating property, can improve the movement capability of the antioxidant, is beneficial to the antioxidant to capture free radicals more quickly, and further inhibits the aging process of the polypropylene better.

The invention also provides a method for preparing the transparent polypropylene resin with optical lighting haze, which is prepared by mixing the components according to the formula ratio and then carrying out melt extrusion.

According to the method, a high-speed mixer is adopted for mixing, and the mixing time is 3-5 min; the melt extrusion adopts a double-screw extruder, double vacuum is opened in the front and rear conveying sections in the melt extrusion process, the gauge pressure of a vacuum meter is less than or equal to-0.08 MPa, the rotating speed of the double-screw extruder is 200-300 r/min, and the value range of the temperature of each zone of the double-screw extruder is 210-230 ℃.

Has the advantages that:

(1) the transparent polypropylene resin with optical lighting haze has excellent transparency when not lighting and excellent haze when lighting;

(2) the transparent polypropylene resin with optical lighting haze of the invention has a light transmittance reduction rate of less than 2% and a haze variation value of less than 1% after lighting for 1500h at 150 ℃.

Detailed Description

The invention will be further illustrated with reference to specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

Example 1

A preparation method of transparent polypropylene resin with optical lighting haze comprises the following steps:

(1) mixing 100 parts by weight of random copolymer polypropylene (PP 5250T) with MI of 22g/10min, 0.5 part by weight of compound nucleating agent (consisting of beta nucleating agent (ADK STAB NA-21) and alpha nucleating agent (WBG-II) in a mass ratio of 5: 2), 0.6 part by weight of sodium polyacrylate resin with a porous structure, 7 parts by weight of anti-aging component (consisting of BASF 168 and 240 ℃ high-temperature-resistant heat-conducting silicon oil in a mass ratio of 1: 8) and 2 parts by weight of polarity modifier (consisting of PP-g-MAH and polyvinyl alcohol in a mass ratio of 1: 5) by adopting a high-speed mixer for 3 min;

(2) adopting a double-screw extruder to melt and extrude to prepare transparent polypropylene resin with optical lighting haze; double vacuum is opened in the front conveying section and the rear conveying section in the melt extrusion process, the gauge pressure of a vacuum gauge is-0.08 MPa, the rotating speed of a double-screw extruder is 200r/min, and the temperature of each zone of the double-screw extruder is 210 ℃.

The transparent polypropylene resin (thickness: 2.0mm) having optically lit haze was obtained, which had a light transmittance of 88% when not lit, a haze of 92% when lit, a light transmittance decrease rate of 1.9% after lighting at 150 ℃ for 1500 hours, and a haze fluctuation value of 0.8% after lighting at 150 ℃ for 1500 hours.

Comparative example 1

A polypropylene resin was prepared in the same manner as in example 1 except that the MI value of the random copolymer polypropylene added in step (1) was 8g/10min (PP M800E), and the polypropylene resin (having a thickness of 2.0mm) was prepared to have a light transmittance of 71% when unlit.

Comparing comparative example 1 with example 1, it can be seen that the light transmittance of the polypropylene resin prepared in example 1 is higher when the polypropylene resin is not lighted, because the use of the high MI random copolymer polypropylene in example 1 improves the mobility of the molecular chain, and improves the grain growth capability and speed of each nucleation point on the basis of compounding the nucleating agent, so that finer grains can be obtained, and finally a high-transmittance polypropylene product is obtained.

Comparative example 2

A process for producing a polypropylene resin, which comprises the same steps as in example 1, except that the MI value of the random copolymer polypropylene added in the step (1) was 45g/10min (PP 5450XT), the polypropylene resin (thickness: 2.0mm) produced had a light transmittance of 89% and a notched impact of 2.3kJ/m when unlit²(ii) a Example 1 had a transmittance of 88% and a notched impact of 4.2kJ/m when unlit²。

As can be seen from comparison of comparative example 2 with example 1, the polypropylene resin prepared in comparative example 2 has no significant difference in light transmittance when unlit from example 1, but has poor mechanical properties because when MI of polypropylene is too high, molecular chains are too short, and thus the obtained polypropylene resin has poor mechanical properties.

Comparative example 3

The preparation method of the polypropylene resin is basically the same as that of the example 1, except that the compound nucleating agent added in the step (1) consists of a beta nucleating agent and an alpha nucleating agent in a mass ratio of 4:3, and the light transmittance of the prepared polypropylene resin (with the thickness of 2.0mm) is 83% when the polypropylene resin is not lighted.

As can be seen from comparison between comparative example 3 and example 1, the polypropylene resin obtained in example 1 has a higher light transmittance when unlit, because the proportion of the α -nucleating agent in comparative example 3 is too large, and when the proportion of the α -nucleating agent is too large, the β -nucleating agent hardly changes the growth state of spherulites, which causes the grain size to become large, so that the light transmittance of the polypropylene resin is reduced.

Comparative example 4

The preparation method of the polypropylene resin is basically the same as that of the example 1, except that the compound nucleating agent added in the step (1) consists of a beta nucleating agent and an alpha nucleating agent in a mass ratio of 6:1, and the light transmittance of the prepared polypropylene resin (with the thickness of 2.0mm) is 81% when the polypropylene resin is not lighted.

As can be seen from comparison of comparative example 4 with example 1, the polypropylene resin obtained in example 1 has a higher light transmittance when unlit, because the α -nucleating agent ratio in comparative example 4 is too small, the number of nucleation sites decreases, the polypropylene segment undergoes more grain growth, the grain size is larger, and the light transmittance of the polypropylene resin also decreases.

Comparative example 5

A method for preparing a polypropylene resin, which comprises the same procedure as in example 1, except that the amount of the sodium polyacrylate resin having a porous structure added in the step (1) is 0.5 parts, and the resulting polypropylene resin (having a thickness of 2.0mm) has a haze of 85% when lit. When comparative example 5 is compared with example 1, it can be seen that the polypropylene resin obtained in example 1 has a higher haze at the time of lighting, indicating that the amount of the atomizing agent should not be too small.

Comparative example 6

A polypropylene resin was prepared in substantially the same manner as in example 1, except that the amount of the sodium polyacrylate resin having a porous structure in step (1) was 1 part, the light transmittance of the resulting polypropylene resin (having a thickness of 2.0mm) was 87% when it was not lit, and that the swelling of the sodium polyacrylate resin in comparative example 6 was excessive, which resulted in deformation of the polypropylene resin-made article, indicating that the amount of the atomizing agent should not be excessive.

Comparative example 7

A process for producing a polypropylene resin, which comprises the same procedure as in example 1 except that in the step (1), a sodium polyacrylate resin having a porous structure was replaced with silicone EP-2720, and the resulting polypropylene resin (having a thickness of 2.0mm) had a haze of 94% when lit and unlit, which was not an optical lighting haze.

Comparative example 8

A polypropylene resin preparation method, which has substantially the same procedure as in example 1, except that no anti-aging component was added in the step (1), and the polypropylene resin (having a thickness of 2.0mm) was obtained with a light transmittance decrease of 6.8% after lighting at 150 ℃ for 1500 hours, and a haze variation of 3.2% after lighting at 150 ℃ for 1500 hours.

Comparing comparative example 8 with example 1, it can be seen that the polypropylene resin obtained in example 1 has lower light transmittance decrease rate and smaller haze variation value after being lighted at 150 ℃ for 1500h, because polypropylene is degraded and generates free radicals during use, and the antioxidant plays a role in capturing free radicals; the heat conducting agent reduces the local temperature of the polypropylene generated by heat absorption due to illumination, and further prevents the polypropylene from being aged by local heating. The antioxidant and the heat conducting agent play a mutual promotion role, and specifically comprise the following components: when the polypropylene product is produced, the heat-conducting agent can form a protective layer on the surface of the product, and the protective layer can isolate the polypropylene from contacting with oxygen and reduce the heat accumulation; in addition, the heat conducting agent has self-lubricating property, and can promote the antioxidant to capture free radicals more quickly, so that the aging process of the polypropylene is better inhibited.

Comparative example 9

A polypropylene resin was prepared in substantially the same manner as in example 1, except that no polar modifier was added in the step (1), and the polypropylene resin (having a thickness of 2.0mm) was obtained with a light transmittance of 74% when unlit.

As can be seen from comparison of comparative example 9 with example 1, the polypropylene resin obtained in example 1 has a higher light transmittance when unlit, because hydroxyl groups on the polyvinyl alcohol chain in the polar modifier react randomly with acid anhydride in PP-g-MAH to form new molecular chains (intermediate product) when blended under heat; because the polypropylene branched chain in the intermediate product is similar to and compatible with the polypropylene chain, the compatibility and the movement of the molecular chain enable a chain entanglement structure to be formed between the polypropylene branched chain and the polypropylene chain, and the chain entanglement further enables rich hydroxyl groups of polyvinyl alcohol to be well distributed around the polypropylene chain segment, so that the hydrophilicity of the polypropylene is improved, the properties that the atomizing agent becomes transparent after absorbing water and is opaque after dehydration are achieved by improving the hydrophilicity, and the light transmittance is improved.

Comparative example 10

A preparation method of polypropylene resin is basically the same as that of example 1, except that the polar modifier added in the step (1) consists of PP-g-MAH and polyvinyl alcohol in a mass ratio of 1:4, and the prepared polypropylene resin (with the thickness of 2.0mm) has a light transmittance of 82% when not lighted; comparing comparative example 10 with example 1, it can be seen that the polypropylene resin obtained in example 1 has higher light transmittance when not lit because the mass ratio of PP-g-MAH to polyvinyl alcohol in comparative example 10 is too small, the reaction sites of hydroxyl and acid anhydride are too many, the viscosity of the system is increased, the MI of the whole system is seriously affected, the crystallization of polypropylene is slowed, and the transparency of the material is deteriorated.

Comparative example 11

A preparation method of polypropylene resin is basically the same as that of example 1, except that the polar modifier added in the step (1) consists of PP-g-MAH and polyvinyl alcohol in a mass ratio of 1:8, and the prepared polypropylene resin (with the thickness of 2.0mm) has a light transmittance of 76% when not lighted; as can be seen from comparison of comparative example 11 with example 1, the polypropylene resin obtained in example 1 has a higher light transmittance when unlit, because the mass ratio of PP-g-MAH to polyvinyl alcohol in comparative example 11 is too large, the intermediate product is too small, the hydrophilicity to polypropylene is not sufficiently improved, and the sodium polyacrylate resin cannot absorb water to become transparent, so that the material remains hazy when unlit.

Example 2

(1) mixing 100 parts by weight of random copolymer polypropylene (PP 5250T) with MI of 22g/10min, 0.6 part by weight of compound nucleating agent (consisting of beta nucleating agent (ADK STAB NA-21) and alpha nucleating agent (WBG-II) in a mass ratio of 5: 2), 0.7 part by weight of sodium polyacrylate resin with a porous structure, 8 parts by weight of anti-aging component (consisting of BASF 168 and high-temperature-resistant heat-conducting silicon oil at 242 ℃) in a mass ratio of 1:9 and 2.5 parts by weight of polar modifier (consisting of PP-g-MAH and polyvinyl alcohol in a mass ratio of 1: 6) by adopting a high-speed mixer for 4 min;

(2) adopting a double-screw extruder to melt and extrude to prepare transparent polypropylene resin with optical lighting haze; double vacuum is opened in the front conveying section and the rear conveying section in the melt extrusion process, the gauge pressure of a vacuum gauge is-0.08 MPa, the rotating speed of a double-screw extruder is 210r/min, and the temperature of each zone of the double-screw extruder is 215 ℃.

The transparent polypropylene resin (thickness: 2.0mm) having optically lit haze was obtained, which had a light transmittance of 89% when not lit, a haze of 94% when lit, a light transmittance decrease rate of 1.1% after lighting at 150 ℃ for 1500 hours, and a haze fluctuation value of 0.3% after lighting at 150 ℃ for 1500 hours.

Example 3

(1) mixing 100 parts by weight of random copolymer polypropylene (PP K4818) with MI of 23g/10min, 0.7 part by weight of compound nucleating agent (consisting of beta nucleating agent (ADK STAB NA-21) and alpha nucleating agent (WBG-II) in a mass ratio of 5: 2), 0.8 part by weight of sodium polyacrylate resin with a porous structure, 9 parts by weight of anti-aging component (consisting of BASF 168 and 244 ℃ high-temperature-resistant heat-conducting silicon oil in a mass ratio of 1: 10) and 3 parts by weight of polarity modifier (consisting of PP-g-MAH and polyvinyl alcohol in a mass ratio of 1: 7) by adopting a high-speed mixer for 5 min;

(2) adopting a double-screw extruder to melt and extrude to prepare transparent polypropylene resin with optical lighting haze; double vacuum is opened in the front conveying section and the rear conveying section in the melt extrusion process, the gauge pressure of a vacuum gauge is-0.08 MPa, the rotating speed of a double-screw extruder is 230r/min, and the temperature of each zone of the double-screw extruder is 220 ℃.

The transparent polypropylene resin (thickness: 2.0mm) having optically lit haze was obtained, which had a light transmittance of 90% when not lit, a haze of 98% when lit, a light transmittance decrease rate of 0.6% after lighting at 150 ℃ for 1500 hours, and a haze fluctuation value of 0.2% after lighting at 150 ℃ for 1500 hours.

Example 4

(1) mixing 100 parts by weight of random copolymer polypropylene (PP HT9025NX) with MI of 25g/10min, 1 part by weight of compound nucleating agent (consisting of beta nucleating agent (ADK STAB NA-21) and alpha nucleating agent (WBG-II) in a mass ratio of 5: 2), 0.7 part by weight of sodium polyacrylate resin with a porous structure, 7 parts by weight of anti-aging component (consisting of BASF 168 and heat-conducting silicone oil resistant to high temperature of 246 ℃) in a mass ratio of 1:8 and 2.2 parts by weight of polar modifier (consisting of PP-g-MAH and polyvinyl alcohol in a mass ratio of 1: 6) by adopting a high-speed mixer for 3 min;

(2) adopting a double-screw extruder to melt and extrude to prepare transparent polypropylene resin with optical lighting haze; double vacuum is opened in the front conveying section and the rear conveying section in the melt extrusion process, the gauge pressure of a vacuum gauge is-0.09 MPa, the rotating speed of the double-screw extruder is 250r/min, and the temperature of each zone of the double-screw extruder is 225 ℃.

The transparent polypropylene resin (thickness: 2.0mm) having optically lit haze was obtained, which had a light transmittance of 92% when not lit, a haze of 95% when lit, a light transmittance decrease rate of 1.6% after lighting at 150 ℃ for 1500 hours, and a haze fluctuation value of 0.7% after lighting at 150 ℃ for 1500 hours.

Example 5

(1) mixing 100 parts by weight of random copolymer polypropylene (PP K4818) with MI of 23g/10min, 0.5 part by weight of compound nucleating agent (consisting of beta nucleating agent (ADK STAB NA-21) and alpha nucleating agent (WBG-II) in a mass ratio of 5: 2), 0.76 part by weight of sodium polyacrylate resin with a porous structure, 7.5 parts by weight of anti-aging component (consisting of BASF 168 and 248 ℃ high-temperature-resistant heat-conducting silicon oil in a mass ratio of 1: 8) and 2.4 parts by weight of polarity modifier (consisting of PP-g-MAH and polyvinyl alcohol in a mass ratio of 1: 5) by adopting a high-speed mixer for 4 min;

(2) adopting a double-screw extruder to melt and extrude to prepare transparent polypropylene resin with optical lighting haze; double vacuum is opened in the front conveying section and the rear conveying section in the melt extrusion process, the gauge pressure of a vacuum gauge is-0.09 MPa, the rotating speed of the double-screw extruder is 270r/min, and the temperature of each zone of the double-screw extruder is 230 ℃.

The transparent polypropylene resin (thickness: 2.0mm) having optically lit haze was obtained, which had a light transmittance of 89% when not lit, a haze of 97% when lit, a light transmittance decrease rate of 1.4% after lighting at 150 ℃ for 1500 hours, and a haze fluctuation value of 0.5% after lighting at 150 ℃ for 1500 hours.

Example 6

(1) mixing 100 parts by weight of random copolymer polypropylene (PP 5250T) with MI of 22g/10min, 0.8 part by weight of compound nucleating agent (consisting of beta nucleating agent (ADK STAB NA-21) and alpha nucleating agent (WBG-II) in a mass ratio of 5: 2), 0.65 part by weight of sodium polyacrylate resin with a porous structure, 8 parts by weight of anti-aging component (consisting of BASF 168 and high-temperature-resistant heat-conducting silicon oil at a mass ratio of 1: 9) and 2.5 parts by weight of polar modifier (consisting of PP-g-MAH and polyvinyl alcohol in a mass ratio of 1: 7) by adopting a high-speed mixer for 4 min;

(2) adopting a double-screw extruder to melt and extrude to prepare transparent polypropylene resin with optical lighting haze; double vacuum is opened in the front conveying section and the rear conveying section in the melt extrusion process, the gauge pressure of a vacuum gauge is-0.09 MPa, the rotating speed of the double-screw extruder is 300r/min, and the temperature of each zone of the double-screw extruder is 215 ℃.

The transparent polypropylene resin (thickness: 2.0mm) having optically lit haze was obtained, which had a light transmittance of 88% when not lit, a haze of 93% when lit, a light transmittance decrease rate of 1.2% after lighting at 150 ℃ for 1500 hours, and a haze fluctuation value of 0.5% after lighting at 150 ℃ for 1500 hours.

Example 7

(1) mixing 100 parts by weight of random copolymer polypropylene (PP 5250T) with MI of 22g/10min, 0.7 part by weight of compound nucleating agent (consisting of beta nucleating agent (ADK STAB NA-21) and alpha nucleating agent (WBG-II) in a mass ratio of 5: 2), 0.7 part by weight of sodium polyacrylate resin with a porous structure, 8 parts by weight of anti-aging component (consisting of BASF 168 and 244 ℃ high-temperature-resistant heat-conducting silicon oil in a mass ratio of 1: 9) and 2.8 parts by weight of polar modifier (consisting of PP-g-MAH and polyvinyl alcohol in a mass ratio of 1: 5) by adopting a high-speed mixer for 4 min;

(2) adopting a double-screw extruder to melt and extrude to prepare transparent polypropylene resin with optical lighting haze; double vacuum is opened in the front conveying section and the rear conveying section in the melt extrusion process, the gauge pressure of a vacuum gauge is-0.09 MPa, the rotating speed of the double-screw extruder is 240r/min, and the temperature of each zone of the double-screw extruder is 218 ℃.

The transparent polypropylene resin (thickness: 2.0mm) having optically lit haze was obtained, which had a light transmittance of 89% when not lit, a haze of 95% when lit, a light transmittance decrease rate of 1.0% after lighting at 150 ℃ for 1500 hours, and a haze fluctuation value of 0.3% after lighting at 150 ℃ for 1500 hours.

Example 8

(1) mixing 100 parts by weight of random copolymer polypropylene (PP HT9025NX) with MI of 25g/10min, 0.6 part by weight of compound nucleating agent (consisting of beta nucleating agent (ADK STAB NA-21) and alpha nucleating agent (WBG-II) in a mass ratio of 5: 2), 0.7 part by weight of sodium polyacrylate resin with a porous structure, 8 parts by weight of anti-aging component (consisting of BASF 168 and 243-temperature-resistant heat-conducting silicone oil in a mass ratio of 1: 10) and 2.7 parts by weight of polar modifier (consisting of PP-g-MAH and polyvinyl alcohol in a mass ratio of 1: 6) by adopting a high-speed mixer for 5 min;

(2) adopting a double-screw extruder to melt and extrude to prepare transparent polypropylene resin with optical lighting haze; double vacuum is opened in the front conveying section and the rear conveying section in the melt extrusion process, the gauge pressure of a vacuum gauge is-0.09 MPa, the rotating speed of the double-screw extruder is 250r/min, and the temperature of each zone of the double-screw extruder is 216 ℃.

Claims

1. A transparent polypropylene resin having optical lighting haze, characterized in that: the composite material comprises polypropylene, an atomizing agent, a polar modifier and a compound nucleating agent, wherein the atomizing agent is sodium polyacrylate resin with a porous structure, and the compound nucleating agent consists of a beta nucleating agent and an alpha nucleating agent;

the transparent polypropylene resin with optical lighting haze mainly comprises, by weight, 100 parts of polypropylene, 0.5-1 part of a compound nucleating agent, 0.6-0.8 part of an atomizing agent, 7-9 parts of an anti-aging component and 2-3 parts of a polar modifier;

the polypropylene is random copolymerization polypropylene with MI of 22-25 g/10 min;

the anti-aging component consists of an antioxidant and a heat conducting agent in a mass ratio of 1: 8-10; the antioxidant is BASF 168, and the heat conducting agent is heat conducting silicone oil resistant to high temperature of 240-250 ℃;

the polar modifier consists of PP-g-MAH and polyvinyl alcohol in a mass ratio of 1: 5-7;

the mass ratio of the beta nucleating agent to the alpha nucleating agent is 5: 2.

2. The transparent polypropylene resin with optical lighting haze according to claim 1, wherein the transparent polypropylene resin with optical lighting haze having a thickness of 2.0mm has a light transmittance of 88 to 92% when unlit, a haze when lit of 92 to 98%, a light transmittance decrease rate of <2% after lighting at 150 ℃ for 1500h, and a haze variation value of <1% after lighting at 150 ℃ for 1500 h.

3. The method for preparing the transparent polypropylene resin with optical lighting haze according to claim 1, wherein: the components are mixed according to the formula ratio and then are melted and extruded to prepare the transparent polypropylene resin with optical lighting haze.

4. The method according to claim 3, wherein the mixing is carried out by a high-speed mixer for 3-5 min; the melt extrusion adopts a double-screw extruder, double vacuum is opened in the front and rear conveying sections in the melt extrusion process, the gauge pressure of a vacuum meter is less than or equal to-0.08 MPa, the rotating speed of the double-screw extruder is 200-300 r/min, and the value range of the temperature of each zone of the double-screw extruder is 210-230 ℃.