CN113174106A

CN113174106A - PP material with high shading rate and high toughness and preparation method thereof

Info

Publication number: CN113174106A
Application number: CN202011463005.XA
Authority: CN
Inventors: 董卫平
Original assignee: Weida Cosmetic Packaging Industrial Co ltd
Current assignee: Weida Cosmetic Packaging Industrial Co ltd
Priority date: 2020-12-14
Filing date: 2020-12-14
Publication date: 2021-07-27

Abstract

The invention belongs to the technical field of materials, and particularly relates to a PP material with high shading rate and high toughness and a preparation method thereof. A PP material with high light shading rate and high toughness comprises the following components in percentage by weight: 5-7% of POE, 35-45% of wollastonite, 0-12% of compound opacifier, 0.3-0.7% of antioxidant, 0.3-0.7% of lubricant and the balance of PP. A preparation method of a PP material with high shading rate and high toughness is used for preparing the PP material and comprises the following steps: s1, preliminary preparation, namely mixing the carbon shading auxiliary agent and the titanium dioxide to prepare a compound opacifier; s2, modifying, namely blending the compound opacifier obtained in the step S1 and wollastonite to modify PP. The invention provides a PP material with excellent shading performance, high shading rate and high toughness, which is applicable to cosmetic box covers, and a preparation method thereof.

Description

PP material with high shading rate and high toughness and preparation method thereof

Technical Field

The invention belongs to the technical field of materials, and particularly relates to a PP material with high shading rate and high toughness and a preparation method thereof.

Background

Polypropylene (PP) is short, is a thermoplastic resin obtained by polymerizing propylene, has the characteristics of strong corrosion resistance at normal temperature, easiness in shaping, light weight, weak conductivity, high thermal stability and the like, is a material with a food safety level specified by the state, and is low in price and widely applied to the aspects of foods, medical instruments, automobiles, chemical containers and the like.

The PP material has certain light transmittance, and pure PP is used as the box cover material and cannot avoid the irradiation of sunlight, so that the direct irradiation of the sunlight can oxidize grease and spices of certain cosmetics and damage pigments, even deteriorate the pigments, and the damage to the cosmetics is great. Therefore, the modification is used for improving the light shielding property of the PP material, and is the key point of the PP material which can be used as a cosmetic box cover material.

The existing PP material can be used for cosmetic cover material less, and the PP material with certain light-shielding property is mostly used for lamp structure, for example, the technical content disclosed in chinese patent CN 110183781A: the flame-retardant PP material suitable for the lamp structural member comprises 80-90 parts of high-crystalline polypropylene, 1-3 parts of a compound flame retardant, 5-10 parts of titanium dioxide, 0-15 parts of talcum powder, 0-5 parts of muscovite, 0.1-0.5 part of an antioxidant, 0.1-0.5 part of a light stabilizer and 0.1-0.5 part of a lubricant; the compound flame retardant is a nitrogen, phosphorus and bromine compound flame retardant system, the nitrogen content is 8 +/-3%, the phosphorus content is 20 +/-3%, the bromine content is 6 +/-3%, the whiteness is more than or equal to 88, and the water content is less than 0.5%.

Although the technical scheme considers that the flame retardance of the material can be improved by adopting the PP base material with high crystallinity and selecting the flame-retardant system compounded by nitrogen, phosphorus and bromine; meanwhile, the high-quality rutile titanium dioxide is compounded to be used for filling and color changing, so that the light shading property, the heat resistance and the long-acting uvioresistant property of the material are improved. However, when the light-shading agent is applied to a cosmetic case cover, the light-shading rate of the cosmetic case cover still cannot meet the use requirement.

Disclosure of Invention

The invention aims to provide a PP material with excellent shading performance, high shading rate and high toughness, which is applicable to cosmetic case covers, and a preparation method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

a PP material with high light shading rate and high toughness comprises the following components in percentage by weight:

POE 5～7％，

35 to 45 percent of wollastonite,

0 to 12 percent of compound opacifier,

0.3 to 0.7 percent of antioxidant,

0.3 to 0.7 percent of lubricant,

and the balance of PP.

The POE is a polyolefin thermoplastic elastomer which is a high-performance polyolefin product, is rubber elastic at normal temperature, and has the characteristics of small density, large bending, high low-temperature impact resistance, easiness in processing, reusability and the like.

Wherein, the lubricant can be stearic acid lubricant, and can also play a role in nucleating and promoting crystallization, polyethylene wax, EBS and the like; the antioxidant can be selected from a main antioxidant 1010 and an auxiliary antioxidant 168, and the main antioxidant 1010 and the auxiliary antioxidant 168 are introduced into PP through blending; the PP may be homopolypropylene.

Preferably, the composition comprises the following components in percentage by weight:

POE 6％，

40 percent of wollastonite,

0 to 12 percent of compound opacifier,

0.5 percent of antioxidant,

0.5 percent of lubricant,

and the balance of PP.

Further, the compound sunscreen agent comprises the following components in percentage by weight:

99.90 to 99.99 percent of titanium dioxide,

the balance of carbon shading auxiliary agent.

Wherein the carbon shading auxiliary agent can be glycol fatty acid ester.

Further, the mass fraction of the compound opacifier is 8%.

Furthermore, the particle size of the wollastonite is 2-20 micrometers, and the mass fraction of the wollastonite is 10-40%.

Meanwhile, the invention also provides a preparation method of the PP material with high shading rate and high toughness, which is used for preparing the PP material and comprises the following steps:

s1, preliminary preparation, namely mixing the carbon shading auxiliary agent and the titanium dioxide to prepare a compound opacifier;

s2, modifying, namely blending the compound opacifier obtained in the step S1 and wollastonite to modify PP.

The invention has the following technical characteristics:

according to the invention, through scientific compatibility of the PP material, the improved PP material not only retains the advantages of the traditional PP material, but also has the characteristics of high shading rate and high toughness, so that the PP material is very suitable for manufacturing cosmetic box covers, can block sunlight irradiation, and prevents oil and perfume of cosmetics from being oxidized and damaging pigments.

Detailed Description

The following specific examples are further illustrative of the methods and techniques provided by the present invention and should not be construed as limiting the invention thereto.

Wherein the CAS number of polypropylene is 9003-07-0, and the CAS number of wollastonite is 1344-95-2.

Specifically, the carbon shading auxiliary agent and the titanium dioxide are mixed in proportion to prepare a compound opacifier, and the compound opacifier is blended with wollastonite to modify PP. The following examples were selected for the light transmittance at different particle sizes and mass fractions of wollastonite.

In the first embodiment, wollastonite with a particle size of 20 microns and a mass fraction of 10% is selected.

Example two, wollastonite with a particle size of 20 microns and a mass fraction of 20% was selected.

Example three, wollastonite with a particle size of 20 microns and a mass fraction of 30% was selected.

Example four, wollastonite was selected with a particle size of 20 microns and a mass fraction of 40%.

Example five, wollastonite was selected having a particle size of 10 microns and a mass fraction of 10%.

Example six, wollastonite with a particle size of 10 microns and a mass fraction of 20% was selected.

Example seven wollastonite with a particle size of 10 microns and a mass fraction of 30% was selected.

Example eight wollastonite with a particle size of 10 microns and a mass fraction of 40% was selected.

Example nine wollastonite with a particle size of 2 microns and a mass fraction of 10% was selected.

In the tenth example, wollastonite with a particle size of 2 μm and a mass fraction of 20% was selected.

In the eleventh embodiment, wollastonite with a particle size of 2 μm and a mass fraction of 30% is selected.

Example twelve, wollastonite was selected having a particle size of 2 microns and a mass fraction of 40%.

As for wollastonite with different particle sizes, the light transmittance of PP shows a gradually decreasing trend along with the increase of the content of the wollastonite, and the light shielding property is gradually improved. This is due to two factors: firstly, the refractive index (1.57) of wollastonite is greater than that (1.49) of PP, the wollastonite has stronger light reflection effect than PP, and due to the difference of the refractive indexes of the wollastonite and the PP, when light penetrates through the PP material, part of the light is reflected at the joint interface of the wollastonite and the PP material, so that the light-shielding effect is achieved; secondly, the particle size of the wollastonite is larger than the wavelength of light waves, and the wollastonite obstructs the light from passing through reflection, diffraction and absorption, so that the light transmittance of the material is reduced, and the light-shielding property is improved.

The influence of the wollastonite particle size on the PP light transmittance is related to the content of the wollastonite particle size, when the wollastonite mass fraction is 10%, the PP light transmittance is continuously reduced along with the decrease of the wollastonite particle size, and the light shielding property is continuously improved; the light-shielding effect is the worst at a particle size of 20 μm, 10 μm times, and 2 μm is the best. When the mass fraction of the wollastonite is 20% or more, the light transmittance of the PP decreases and then increases with the decrease in the particle diameter, that is, the light-shielding property is first improved and then reduced. This indicates that, at a low content, the smaller the particle size of wollastonite, the better the light-shielding property; at a high content, wollastonite having a small particle diameter rather lowers the light-shielding property. When the content of the wollastonite is lower, the specific surface area of the wollastonite is increased along with the reduction of the particle size, reflection and scattering interfaces are increased, and reflected and refracted rays are increased, so that the light-shielding property is improved; with the increase of the content of the wollastonite, the wollastonite with small particle size is agglomerated, and reflected and scattered light is reduced, so that the light-shielding property is reduced. The comparison shows that when the particle size of the wollastonite is 10 μm and the mass fraction is 40%, the light transmittance of PP is the lowest and the light shielding performance is the best, so that 10 μm wollastonite is selected as a research object, and the mass fraction is fixed to be 40%.

In order to research the influence of the proportion of titanium dioxide and carbon shading auxiliary agent on the PP shading performance in the compound shading agent, the titanium dioxide is used as a main component, the carbon shading auxiliary agent is used as an auxiliary component, and the titanium dioxide and the carbon shading auxiliary agent are mixed according to different proportions to prepare the compound shading agent, which is respectively the following thirteen to fifteen embodiments, and the following table shows that:

in order to better embody the research result, two groups of comparative examples are provided, namely a comparative example I: pure PP material, comparative example two: PP material and single titanium dioxide.

Wherein the mass fraction of the titanium dioxide and the three compound opacifiers is 8 percent.

The light shading performance of the PP material is remarkably improved by adding the opacifier, and when the wavelength is 780nm, the light transmittance of the thirteen embodiment, the fourteen embodiment and the fifteen embodiment is reduced by more than 98 percent compared with that of the first comparative embodiment; the light transmittance (0.017%) of the thirteen examples was reduced by 26% compared to the light transmittance (0.023%) of the comparative example two, while the light transmittance (0.009%, 0.003%) of the fourteen and fifteen examples was reduced by 60.9% and 87%, respectively. The reason is that titanium dioxide has the characteristics of light reflection and light scattering, the carbon shading auxiliary agent has the characteristic of strong light absorption, and the titanium dioxide and the carbon shading auxiliary agent are compounded to generate a synergistic effect and have the capabilities of reflecting light and absorbing light, so that the shading effect of the titanium dioxide is better than that of pure titanium dioxide. The proportion change of the titanium dioxide and the carbon shading auxiliary agent in the compound opacifier has obvious influence on the shading property of PP, the PP added in the embodiment fifteen has the best shading effect, which is mainly related to the action of the carbon shading auxiliary agent, the titanium dioxide content in the three compound opacifiers is higher, the micro change can not influence the reflection action of the compound opacifiers on light, the content of the carbon shading auxiliary agent is extremely low, the micro change can obviously influence the absorption action of the compound opacifiers on light, the absorption capacity of the compound opacifiers on light is enhanced along with the increase of the content of the carbon shading auxiliary agent, light can not penetrate through the material, and therefore the shading property is improved.

After 8% of compound opacifier is added, the light transmittance of the PP material is far less than 0.1% and is close to zero, but the light transmittance can only represent the shading trend of the material, and whether light penetrates when the material is irradiated by a strong light source cannot be proved. Therefore, a sample plate having a thickness of 1mm was irradiated with an intense light source, and the light transmittance was visually observed. When the diameter of the light spot is smaller, the light intensity is weaker, the light-shielding property of the material is better, and otherwise, the light-shielding property is poorer.

The light spot of the comparative example I is the largest, the diameter is 36mm, and the light is strong and dazzling; in the comparative example, the diameter of the light spot is reduced to 15mm, and the light intensity is weakened; the diameters of the light spots of the thirteen embodiment, the fourteen embodiment and the fifteen embodiment are respectively reduced to 13mm, 11mm and 9mm, the diameters are gradually reduced, and the light intensity is weaker and weaker. The light-shielding property of PP is improved better in each of the thirteenth, fourteenth and fifteenth embodiments than in the second comparative example, wherein the light-shielding property of the fifteenth embodiment is the best. The compound opacifier obviously improves the light-shading property of PP, and the light-shading result is consistent with the light transmittance test result.

Specifically, to further verify the properties of the PP material of the present invention, based on the fifteen examples, the following six groups of examples with different amounts of formulated sunscreen agent are provided, which are respectively sixteen to twenty one examples. As shown in the following table, the mass fractions (%) of the components of the examples are as follows:

examples	PP	POE	Wollastonite	Titanium white powder	Antioxidant agent	Lubricant agent
							Example sixteen	53	6	40	0	0.5	0.5
Example seventeen	50	6	40	3	0.5	0.5
							EXAMPLE eighteen	48	6	40	5	0.5	0.5
Example nineteen	45	6	40	8	0.5	0.5
							Example twenty	43	6	40	10	0.5	0.5
Example twenty one	41	6	40	12	0.5	0.5

The mechanical properties and MFR of the modified PP material obtained with the different amounts of the compounded sunscreen agent in the above examples are shown in the following table:

as can be seen from the above table, with the increase of the content of the compound opacifier of the fifteen example, the change range of the tensile strength and the elongation at break of the PP/wollastonite is not large, the impact strength and the bending strength are slightly improved, and the MFR is slightly reduced. The compound opacifier belongs to an inorganic substance, has small particle size and large specific surface area, enhances uniform dispersibility in PP matrix resin, increases the coated area by the matrix resin, has strong mutual interface action, has small damage to the continuous phase of the composite material, is beneficial to reducing the generation of stress concentration defects, can uniformly transfer external stress, and has small influence on the mechanical property of the material. Meanwhile, the addition of the compound opacifier increases the internal friction resistance among matrix resins and weakens the relative movement among molecules, thereby reducing the MFR of the material.

The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core ideas. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. The PP material with high light shading rate and high toughness is characterized by comprising the following components in percentage by weight:

POE 5～7％，

35 to 45 percent of wollastonite,

0 to 12 percent of compound opacifier,

0.3 to 0.7 percent of antioxidant,

0.3 to 0.7 percent of lubricant,

and the balance of PP.

2. The high opacity, high toughness PP material according to claim 1, wherein it comprises the following components in weight percent:

POE 6％，

40 percent of wollastonite,

0 to 12 percent of compound opacifier,

0.5 percent of antioxidant,

0.5 percent of lubricant,

and the balance of PP.

3. The high opacity, high toughness PP material according to claim 1 or 2, wherein the compound sunscreen agent comprises the following components in percentage by weight:

99.90 to 99.99 percent of titanium dioxide,

the balance of carbon shading auxiliary agent.

4. The high opacity, high toughness PP material according to claim 3, wherein the mass fraction of the built opacifier is 8%.

5. The PP material with high light shading rate and high toughness as claimed in claim 1 or 2, wherein the particle size of the wollastonite is 2-20 μm, and the mass fraction of the wollastonite is 10-40%.

6. A process for the preparation of a high tenacity, high opacity PP material, characterized in that it is used for the preparation of a PP material according to any one of claims 1 to 5, comprising the steps of: