CN114410144B

CN114410144B - Anti-settling glass bead for hot-melt marking paint

Info

Publication number: CN114410144B
Application number: CN202210183261.6A
Authority: CN
Inventors: 杜利民; 侯涛; 高伟; 牛文斌; 李鹏; 程晓飞
Original assignee: Shanxi Zhongtu Traffic Technology Co ltd
Current assignee: Shanxi Zhongtu Traffic Technology Co ltd
Priority date: 2022-02-25
Filing date: 2022-02-25
Publication date: 2023-03-10
Anticipated expiration: 2042-02-25
Also published as: CN114410144A

Abstract

The invention discloses a sedimentation-proof glass bead for hot-melt marking paint, which is formed by pretreating the surface of the glass bead by using a silane coupling agent, bonding and wrapping a bonding component containing an expanding agent on the surface of the pretreated glass bead by using the silane coupling agent, and coating a sealing agent on the outer surface of the bonding component containing the expanding agent. According to the invention, the foaming material is bonded on the surface layer of the glass bead, and the substance with strong covering power is wrapped outside the foaming material, so that on one hand, the foaming material is heated and decomposed to form a closed expanded porous structure, the buoyancy of the glass bead is improved, on the other hand, the light reflection effect of the glass bead is improved, and the problems of poor road marking light reflection performance and coating waste caused by the sedimentation of the glass bead in the construction process of the hot-melt marking coating are effectively solved.

Description

Anti-settling glass bead for hot-melt marking paint

Technical Field

The invention belongs to the technical field of road marking coatings, relates to a hot-melt marking coating, and particularly relates to an inner-mixing or surface-scattering glass bead for the hot-melt marking coating.

Background

The road marking is one of important traffic safety facilities, and clear and standard markings can provide clear and safe guidance for traffic participants. The hot-melt type road marking mainly comprises petroleum resin, heavy calcium powder, quartz sand, premixed glass beads, pigment, plasticizer and the like, and is the road marking with the highest proportion in expressways and trunk roads of China.

Clear and bright road marking guidance is more needed for safe driving of vehicles at night, and as no lighting facilities are basically arranged on expressways and national and provincial main roads, very high requirements are put on the night identifiability of the hot melt type road markings of the road sections.

The road marking line does not emit light, but the light emitted by the vehicle lamp can be reflected back to the visual field range of a driver through the glass beads on the marking line, so that the marking line emits light and shines, and the driver can clearly see the lane dividing line and the driving indication.

These glass beads may be classified into a premix type and a scatter type. The premixed glass beads are used as necessary components in the coating, are directly added into the coating in the production process of the reflective hot-melt marking coating, and mainly play a role in reflecting light after the surface layer of the road marking is abraded. The surface scattering type glass beads are used as a reflecting medium for providing the initial reflecting performance of the road marking, and are additionally scattered on the surface of the marking during the construction of marking paint.

In the case of road marking paints, an important indicator of the useful life or performance of the paint is the reflective properties of the paint, and the coefficient of retroreflection brightness can be used as characterization data.

Two factors are mainly used for influencing the retroreflection brightness coefficient, one is the performance of the glass beads, and the performance mainly comprises the refractive index and the circularity of the glass beads; the second is to control the spreading of the surface and the sedimentation of the premixed glass beads during the construction. The specific requirement is that 50-60% of the surface-scattered glass beads are sunk in the coating, and the coating has better light reflecting performance and firm bonding force; the premixed glass beads need to be properly settled and uniformly distributed in the coating without precipitation.

However, because the performance of hot-melt road marking paint in China is uneven, construction teams and construction equipment technologies are lagged behind, field control is not in place, and the like, the glass beads in the following various situations are not properly settled.

1. The viscosity of the road marking paint is too low, so that the premixed glass beads are settled at normal construction temperature, the paint cannot be constructed to cause waste, the proportion of the premixed glass beads of the constructed road marking can not meet the requirement, the later-stage reflective performance of the marking is not enough, and the initial-stage reflective performance is reduced due to excessive settlement of the surface-scattered glass beads.

Although the above-mentioned sedimentation problem can be solved by lowering the application temperature to achieve a suitable sedimentation of the glass beads by increasing the viscosity of the coating, the lowering of the application temperature leads to a decrease in the adhesion of the marking coating, and in particular, in the case of a low ambient temperature, the problem of the falling off of the road marking occurs.

2. The construction of the road marking is carried out on the road section of a passing vehicle in many times, and various emergency situations can be met, so that the situation that the coating is excessively heated sometimes occurs. After the paint is heated excessively, the viscosity is reduced, so that components with larger specific gravity, such as glass beads, are settled, and the material waste or the construction quality does not reach the standard is caused.

3. In the construction process, due to working negligence, stirring is not timely, or the stirring time of the coating is not satisfactory for saving fuel, and the glass beads with larger specific gravity in the coating are also settled.

4. Some road marking projects require the glass beads with the inner mixed particle size of 20 meshes or even larger, and the premixed glass beads have large weight and smooth surface and are very easy to settle on the bottom layer of the coating. Because the bottom glass beads of the road marking are enriched and lack sufficient bonding materials, the bonding force of the marking is poor, and the falling is caused to influence the effective service life of the road marking.

Disclosure of Invention

The invention aims to provide anti-settling glass beads for a hot-melt type marking paint, and aims to solve the problem of poor road marking light reflection performance caused by excessive precipitation of the glass beads in the construction process of the hot-melt type marking paint.

The anti-settling glass bead for the hot-melt type marking paint is formed by pretreating the surface of the glass bead by using a silane coupling agent, bonding and wrapping a bonding component containing an expanding agent on the surface of the pretreated glass bead by using the silane coupling agent, and wrapping a sealing agent on the outer surface of the bonding component containing the expanding agent.

Further, the adhesive component is a mixed solution of adhesive resin and thermoplastic elastomer dissolved in a liquid solvent and having a viscosity of 20 to 150 mPas at 70 ℃.

Further, the liquid solvent is any one of dioctyl phthalate (DOP), dibutyl phthalate (DBP), naphthenic oil and industrial white oil, or a mixture of several of the above in any proportion.

In the present invention, the boiling point of the liquid solvent is not lower than 100 ℃.

Furthermore, the bonding resin is any one of C5 petroleum resin, C9 hydrogenated petroleum resin, maleic anhydride modified rosin resin and thermoplastic epoxy resin or a mixture of the above resins in any proportion.

Furthermore, the thermoplastic elastomer is any one of Thermoplastic Polyurethane (TPU), styrene thermoplastic elastomer, thermoplastic polyolefin elastomer and ethylene-vinyl acetate copolymer (EVA), or a mixture of several of the above in any proportion.

More specifically, the styrene-based thermoplastic elastomer may include any one of styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS), or a mixture of several of them in any proportion.

Furthermore, the expanding agent is specifically a foaming material with the decomposition temperature of 50-220 ℃.

Further, the expanding agent can include, but is not limited to, any one of ammonium phosphate, ammonium polyphosphate, glycine, dicyandiamide and urea, or a mixture of the ammonium phosphate, the ammonium polyphosphate, the glycine, the dicyandiamide and the urea in any proportion.

More preferably, the expanding agent of the present invention is a micron-sized foaming material.

The expanding agent is used as a foaming material, and is uniformly coated on the outer surface of the glass bead by the carrier bonding component. After the marking paint is heated to a certain temperature, the micron-sized expanding agents begin to decompose and release gas, a porous structure is formed inside the bonding component, and the micro bubbles are stably adhered to the outer surface of the glass beads to form a micro-expanded wrapping layer, so that certain buoyancy is provided, and the glass beads are guaranteed to be uniformly suspended inside the paint without excessively sinking.

Furthermore, the sealing agent is a material with better covering power and good compatibility with a coating system, such as titanium dioxide or barium sulfate and the like. The use of the sealant can reduce mutual adhesion between the glass beads wrapped with the bonding components on one hand, and can improve the light reflection performance of the glass beads on the other hand.

According to the optical principle of the road marking glass bead, the sealing agent coated on the outermost layer can also improve the retroreflective brightness coefficient of the road marking, which mainly means that the sealing agent has good covering power and can reduce the refraction proportion of an incident light source in the glass bead so as to enable more light sources to reflect and emit bright light,

in general, for white hot melt type marking paints, the sealant used in the present invention is preferably rutile titanium dioxide, followed by anatase titanium dioxide. For yellow hot-melt type marking paint, in order to ensure that the marking color meets the standard requirements, the marking paint can be selected and compounded with 5-50% rutile type titanium dioxide by using yellow pigment.

Specifically, in the anti-settling glass bead for the hot-melt marking paint, the dosage of the bonding component is 5-20% of the mass of the glass bead, the dosage of the expanding agent is 5-30% of the mass of the bonding component, and the dosage of the sealing agent is 5-30% of the mass of the bonding component.

More specifically, the invention carries out surface pretreatment on the glass beads of the reflecting main body by using a silane coupling agent, and aims to improve the bonding strength between the glass beads and bonding resin in bonding components, ensure that the bonding components containing the expanding agent can be firmly bonded on the surface layers of the glass beads, and reduce the loss of the expanding agent in the coating.

The silane coupling agent used in the present invention is not particularly limited, and may be various conventional silane coupling agents. For example, vinyl silane, amino silane, methacryloxy silane, and the like, which are the more common silane coupling agents, can be used. Except silane with alkalinity such as amino silane, the rest silane can be prepared into solution with certain concentration by water or alcohol, and then the pH value is adjusted to 3.5-5 by acetic acid.

The invention also provides a preparation method of the anti-settling glass bead for the hot-melt type marking paint, which is characterized in that bonding resin and thermoplastic elastomer are dissolved in a liquid solvent to obtain a mixed solution with the viscosity of 20-150 mPa & s at 70 ℃ as a bonding component, then an expanding agent is uniformly dispersed in the bonding component to obtain a bonding component containing the expanding agent, then glass beads pretreated by adopting a silane coupling agent in advance are added, the glass beads are rotated and rolled to ensure that the glass beads pretreated by the silane coupling agent are uniformly wrapped by the bonding component containing the expanding agent, and finally a layer of sealing agent is wrapped on the outer layer of the bonding component containing the expanding agent to prepare the anti-settling glass bead for the hot-melt type marking paint.

In brief, the anti-settling glass bead for the hot-melt type marking paint is formed by uniformly wrapping a layer of compressed sponge material on the surface layer of the glass bead. Before the glass pearl is heated, this layer of spongy material remains throughout and compresses tightly the state, and after the heating reached the uniform temperature, spongy material began to expand gradually, nevertheless remains inseparable bonding state with the glass pearl throughout, provides bigger buoyancy for the glass pearl after the inflation, guarantees that the glass pearl can not excessively deposit.

Therefore, the anti-settling glass bead for the hot-melt type marking paint prepared by the invention can be used as an internal mixing and/or surface scattering glass bead of the hot-melt type marking paint.

When the coating is used as internal mixing glass beads, the hot melting marking coating mixed with the anti-settling glass beads is heated in a hot melting kettle and begins to gradually rise in temperature for melting, when the temperature rises to a certain temperature, the expanding agent begins to decompose to generate gas to form micro bubbles, and the micro bubbles are uniformly wrapped on the surface layers of the glass beads, so that the glass beads can be uniformly suspended in the coating and are prevented from settling at the bottom of the kettle. After the marking construction, interior muddy glass pearl evenly distributed is inside the marking coating, through the wearing and tearing of tire, exposes the glass pearl body after sealant and the bonding component on anti-settling glass pearl upper epidermis are worn and torn, with in normally thoughtlessly mixing glass pearl the same performance of reflecting light to because the latter half of glass pearl is covered by bonding component and sealant, can improve the contrary reflective effect of road marking.

And for the surface scattering glass beads, the light reflecting performance can be exerted without abrasion. The glass beads are spread on the surface of the marking paint before the paint is cured during paint construction, and the part embedded in the paint is reflected by light, and the part exposed out of the marking paint is refracted by light. The light rays return to the field of vision of the driver via refraction (into the interior of the glass beads) → reflection (the portion of the glass beads embedded in the coating) → refraction (the light rays exiting the glass beads).

Detailed Description

The following examples are given to further illustrate the embodiments of the present invention. The following examples are only for more clearly illustrating the technical solutions of the present invention so as to enable those skilled in the art to better understand and utilize the present invention, and do not limit the scope of the present invention.

The names and abbreviations of the experimental methods, production processes, instruments and equipment involved in the examples and comparative examples of the present invention are those commonly known in the art and are clearly and clearly understood in the relevant fields of use, and those skilled in the art can understand the conventional process steps and apply the corresponding equipment according to the names and perform the operations according to the conventional conditions or conditions suggested by the manufacturers.

The various starting materials or reagents used in the examples of the present invention and comparative examples are not particularly limited in terms of their sources, and are all conventional products commercially available. They may also be prepared according to conventional methods well known to those skilled in the art.

Example 1.

Weighing 15g of SBS, 20g of C5 petroleum resin and 5g of epoxy resin, adding into 120g of DOP, slowly stirring, heating to 80 ℃, and completely dissolving to obtain the bonding component.

And maintaining the temperature at 80 ℃, adding 2g of ammonium phosphate, 8g of ammonium polyphosphate and 10g of dicyandiamide, and stirring while keeping the temperature until the mixture is uniformly dispersed to obtain the bonding component containing the expanding agent.

Adding 500g of national standard No. 1 glass beads into a stirring kettle heated to 50 ℃, slowly dropwise adding 25g of 20wt% vinyl triethoxysilane ethanol solution with the pH value of 4.5 while stirring, and continuously stirring and reacting for 0.5h after dropwise adding is finished to prepare the silane coupling agent pretreated glass beads.

Uniformly spraying the prepared bonding component containing the expanding agent on the silane coupling agent pretreated glass beads, mixing and stirring for 0.5h, naturally cooling to room temperature, adding 15g of titanium dioxide serving as a sealing agent, and continuously stirring for 0.5h to prepare the anti-settling glass beads.

Example 2.

20g of SIS and 10g of epoxy resin are weighed and added into 130g of white oil, the temperature is raised to 90 ℃ under slow stirring, and the bonding component is obtained after complete dissolution.

Maintaining the temperature at 90 ℃, adding 20g of ammonium phosphate and 10g of ammonium polyphosphate, and stirring while keeping the temperature until the mixture is uniformly dispersed to obtain the bonding component containing the expanding agent.

Adding 500g of glass beads American Standard No. 3 into a stirring kettle heated to 50 ℃, slowly dropwise adding 25g of ethanol solution of 18wt% of N-beta- (aminoethyl) -gamma-aminopropylmethyldimethoxysilane under stirring, and after the dropwise addition, continuing stirring for reaction for 0.5h to prepare the silane coupling agent pretreated glass beads.

Uniformly spraying the prepared bonding component containing the expanding agent on the silane coupling agent pretreated glass beads, mixing and stirring for 0.5h, naturally cooling to room temperature, adding 10g of titanium dioxide serving as a sealing agent, and continuously stirring for 0.5h to prepare the anti-settling glass beads.

Example 3.

And weighing 20g of SEBS and 40g of epoxy resin, adding into 120g of naphthenic oil, slowly stirring, heating to 70 ℃, and completely dissolving to obtain the bonding component.

And maintaining the temperature at 70 ℃, adding 5g of ammonium phosphate, 2g of glycine and 8g of dicyandiamide, and keeping the temperature and stirring until the mixture is uniformly dispersed to obtain the bonding component containing the expanding agent.

Adding 500g of national standard No. 2 glass beads into a stirring kettle heated to 50 ℃, slowly dripping 25g of 18wt% vinyl trimethoxy silane aqueous solution with the pH value of 4 while stirring, and continuously stirring for reacting for 0.5h after dripping is finished to prepare the silane coupling agent pretreated glass beads.

Uniformly spraying the prepared bonding component containing the expanding agent on the silane coupling agent pretreated glass beads, mixing and stirring for 0.5h, naturally cooling to room temperature, adding 50g of titanium dioxide serving as a sealing agent, and continuously stirring for 0.5h to prepare the anti-settling glass beads.

Example 4.

Weighing 10g of SBS and 20g of modified rosin resin, adding into 130g of DOP, slowly stirring, heating to 70 ℃, and completely dissolving to obtain the bonding component.

Maintaining the temperature at 70 ℃, adding 15g of ammonium polyphosphate, 2g of glycine, 5g of dicyandiamide and 3g of urea, and stirring while keeping the temperature until the mixture is uniformly dispersed to obtain the bonding component containing the expanding agent.

Adding 500g of national standard No. 2 glass beads into a stirring kettle heated to 50 ℃, slowly dropwise adding 25g of 25wt% gamma-methacryloxypropyl trimethoxy silane ethanol solution with the pH value of 4.5 while stirring, and continuously stirring for reaction for 0.5h after dropwise adding to prepare the silane coupling agent pretreated glass beads.

Uniformly spraying the prepared bonding component containing the expanding agent on the silane coupling agent pretreated glass beads, mixing and stirring for 0.5h, naturally cooling to room temperature, adding 20g of titanium dioxide serving as a sealing agent, and continuously stirring for 0.5h to prepare the anti-settling glass beads.

Example 5.

11g of SEBS, 2g of SIS and 10g of C9 hydrogenated petroleum resin are weighed and added into a mixed solution of 50g of DOP and 70g of naphthenic oil, the temperature is raised to 60 ℃ under slow stirring, and the bonding component is obtained after complete dissolution.

Maintaining the temperature at 60 ℃, adding 8g of ammonium phosphate and 2g of glycine, and stirring while keeping the temperature until the mixture is uniformly dispersed to obtain the bonding component containing the expanding agent.

Adding 500g of national standard No. 2 glass beads into a stirring kettle heated to 50 ℃, slowly dropwise adding 25g of 20% gamma-aminopropyltriethoxysilane aqueous solution while stirring, and continuously stirring for reaction for 0.5h after dropwise adding is finished to prepare the silane coupling agent pretreated glass beads.

Uniformly spraying the prepared bonding component containing the expanding agent on the silane coupling agent pretreated glass beads, mixing and stirring for 0.5h, naturally cooling to room temperature, adding 30g of titanium dioxide serving as a sealing agent, and continuously stirring for 0.5h to prepare the anti-settling glass beads.

Comparative example 1.

And uniformly spraying the prepared bonding component on the silane coupling agent pretreated glass beads, mixing and stirring for 0.5h, naturally cooling to room temperature, adding 15g of titanium dioxide serving as a sealing agent, and continuously stirring for 0.5h to prepare the anti-settling glass beads.

Comparative example 2.

500g of glass beads No. 3 Meibiao was charged into a stirred tank heated to 50 ℃ and 25g of ethanol solution of 18wt% N-. Beta. - (aminoethyl) - γ -aminopropylmethyldimethoxysilane was slowly added dropwise with stirring, and after completion of the dropwise addition, the stirring reaction was continued for 0.5 hour to prepare pretreated glass beads of a silane coupling agent.

And uniformly spraying the prepared bonding component on the silane coupling agent pretreated glass beads, mixing and stirring for 0.5h, naturally cooling to room temperature, adding 10g of titanium dioxide serving as a sealing agent, and continuously stirring for 0.5h to prepare the anti-settling glass beads.

Comparative example 3.

The glass beads of national standard No. 2 without any treatment were used directly.

Example 1 is applied.

Using the anti-settling glass beads prepared in examples 1 to 5 and comparative examples 1 to 2, and the untreated glass beads of comparative example 3, respectively, hot melt coatings were prepared according to the following formulations: 185g of C5 petroleum resin, 12.5g of PE wax, 6g of white oil, 700g of heavy calcium carbonate, 12g of EVA, 300g of glass beads, 50g of titanium dioxide, and the total amount

g。

Respectively heating and fully stirring the hot-melt coatings uniformly, pouring the hot-melt coatings into a cylindrical mold with the diameter of 5cm and the height of 30cm when the temperature reaches 220 ℃, standing, cooling and solidifying.

The test block was taken out, the bottom and the top were polished flat, and then cut into 3 sections on average, and the mass of each section was measured, and the specific results are listed in table 1.

The results in Table 1 show that the masses of the test blocks in the upper, middle and lower sections of examples 1-5 are relatively uniformly distributed, and the mass difference between every two adjacent test blocks is not more than 10g.

Compared with the comparative example 1, the glass beads of national standard No. 1 with the same particle size are adopted in the example 1, but the expansion agent is not added into the glass beads in the comparative example 1, so that the mass difference of two adjacent test blocks reaches 25g, and the mass distribution of three test blocks in the example 1 is uniform and is only 3g at most.

Compared with the comparative example 2, the glass beads of American standard No. 3 with the same particle size are adopted in the example 2, but as the comparative example 2 does not add the expanding agent to the glass beads, the mass difference of two adjacent test blocks reaches 40g at most and 30g at least, and the mass distribution of the three test blocks in the example 2 is uniform and only has 10g at most.

Compared with the examples 3-5, the comparative example 3 adopts the glass beads with the same grain size, but the quality of the three-stage test block of the comparative example 3 is very different, and particularly the quality of the middle section and the bottom section is different by 58g. Although the glass beads of national standard No. 2 with the smallest average particle size are adopted, the sedimentation is also very serious, and if the glass beads are changed into the glass beads with large particle sizes, the sedimentation is more serious.

Example 2 is applied.

Using the anti-settling glass beads prepared in examples 1 to 5 and comparative examples 1 to 2, and the untreated glass beads of comparative example 3, respectively, hot melt coatings were prepared according to the following formulations: 1.85kg of C5 petroleum resin, 125g of PE wax, 60g of white oil, 7kg of heavy calcium carbonate, 120g of EVA, 3kg of glass beads, 0.5kg of titanium dioxide and 12.65kg of total weight.

And respectively heating and fully stirring the hot-melt coatings uniformly, and when the temperature reaches 220 ℃, forming a road marking with the length of 3m, the width of 0.2m and the thickness of 2mm on the asphalt pavement of the test section in a blade coating mode, wherein glass beads are not scattered on the surface of the road marking.

By using a cleanerThe road marking prepared in examples 1-5 and comparative examples 1-3 is ground in sequence by the same working parameters in a sweeping machine grinding mode, and the abrasion of the road marking by the simulated tire is accelerated. After each road marking is continuously polished for 6 times, a retroreflection brightness coefficient test is carried out, 6 points are taken for testing, and the average value of test results is taken. The results are shown in Table 2, and the coefficient of retroreflection luminance is given in mcd 8729m ^-2 ∙lx ^-1 。

Because the glass beads are not scattered on the surface of the road marking in construction, and the light reflection performance is mainly exerted by the glass beads, the test result before polishing is very low.

Examples 1-5 retroreflection luminance coefficient values all increased to 200mcd 8729m after the first sanding treatment ^-2 ∙lx ^-1 As shown above, the internal mixed glass beads begin to play a role in reflecting light, and then can still be maintained at 200-300 mcd 8729m until the 5 th test ^-2 ∙lx ^-1 And peaks at the 2 nd test. Later on, although gradually attenuated, the attenuation period is relatively long, and the reflecting effect in the limited service life of the road marking can be ensured. In the 6 th test, the road marking has been worn seriously, the coefficient of retroreflection brightness is reduced obviously, but the initial coefficient of retroreflection brightness of the white marking in China is larger than 150mcd 8729m ^-2 ∙lx ^-1 The standard requirements of (2).

Comparing example 1 with comparative example 1, the retroreflective luminance coefficient of example 1 already reached 200mcd 8729m ^-2 ∙lx ^-1 Whereas comparative example 1 reached 200mcd 8729m on the 4 th test ^-2 ∙lx ^-1 Above and decays rapidly to 200mcd 8729m after the 6 th test ^-2 ∙lx ^-1 The following description shows that the glass beads in the road marking coating of example 1 are uniformly distributed, and as the marking is worn, the newly exposed glass beads in the coating and the worn glass beads are basically balanced, and the light reflection performance can also be realizedThe relative stability is kept; in comparative example 1, the glass beads are not treated by adding the expanding agent, and the glass beads are seriously settled in the coating, so that the internal mixed glass beads are not exposed all the time when the glass beads are worn in the early stage, the reflective performance cannot meet the requirement, and the reflective performance is reversely and rapidly improved in the later stage due to more internal mixed glass beads at the bottom layer.

Compared with the example 1, the example 2 uses American standard No. 3 internal mixing glass beads, has larger grain diameter compared with the national standard No. 1 glass beads of the example 1, can be quickly worn out to expose the surface layer of the coating, and plays a role in reflecting light. However, since the glass bead of U.S. Pat. No. 3 has a larger particle size, the adhesion to the glass bead is reduced and the glass bead falls off more rapidly due to the thinness of the coating layer during later wear, which leads to the decrease of the reflective performance of the later-stage marked line rather than that of the embodiment 1.

Comparing example 2 with comparative example 2, the variation tendency of the retroreflective brightness coefficient test result is substantially similar to that of example 1 and comparative example 1. However, comparative example 2 reached a peak of 338mcd 8729m at the 5 th test ^-2 ∙lx ^-1 The reason is that the comparative example 2 does not add the expanding agent to the glass beads, the glass beads are seriously settled in the coating, the bottom layer is greatly enriched, and a large amount of internal mixing glass beads are exposed when the coating is abraded to a certain degree, so that the light reflecting performance of the road marking is rather good. However, as the large-particle-size glass beads are enriched in the bottom layer and the paint bonding component is relatively few, a large number of glass beads at the position can rapidly fall off along with the abrasion of the marking coating, so that the light reflecting performance is rapidly reduced.

Compared with comparative example 3, the glass beads of the national standard No. 2 are adopted in the examples 3 to 5, but the glass beads are not treated in the comparative example 3, the precipitation in a coating system is the most serious, and the glass beads can reach 200mcd 8729m when tested for the 4 th time ^-2 ∙lx ^-1 The temperature quickly decays to 200mcd 8729m when tested for the 6 th time ^-2 ∙lx ^-1 The following. In contrast, the test results of examples 3-5 were all maintained at 200mcd 8729m from test 1 to test 5 ^-2 ∙lx ^-1 Therefore, under the real use state, the road marking can keep the excellent light reflecting effect for a long time。

The above embodiments of the present invention are not intended to be exhaustive or to limit the invention to the precise form disclosed. Various changes, modifications, substitutions and alterations to these embodiments will be apparent to those skilled in the art without departing from the principles and spirit of this invention.

Claims

1. The anti-settling glass bead for the hot-melt marking paint is formed by pretreating the surface of a glass bead by adopting a silane coupling agent, bonding and wrapping a bonding component containing an expanding agent on the surface of the pretreated glass bead by using the silane coupling agent, and coating a sealing agent on the outer surface of the bonding component containing the expanding agent;

wherein the bonding component is a mixed solution which is formed by dissolving bonding resin and thermoplastic elastomer in a liquid solvent and has the viscosity of 20-150 mPa & s at 70 ℃, and the using amount of the mixed solution is 5-20% of the mass of the glass beads; the bonding resin is any one of C5 petroleum resin, C9 hydrogenated petroleum resin, maleic anhydride modified rosin resin and thermoplastic epoxy resin or a mixture of the above resins in any proportion; the thermoplastic elastomer is any one of thermoplastic polyurethane, styrene thermoplastic elastomer, thermoplastic polyolefin elastomer and ethylene-vinyl acetate copolymer or a mixture of several of the thermoplastic polyurethane, the styrene thermoplastic elastomer and the thermoplastic polyolefin elastomer in any proportion;

the expanding agent is any one of foaming materials of ammonium phosphate, ammonium polyphosphate, glycine, dicyandiamide and urea with the decomposition temperature of 50-220 ℃, or a mixture of a plurality of foaming materials in any proportion, and the using amount of the expanding agent is 5-30% of the mass of the bonding component;

the sealing agent is titanium dioxide or barium sulfate, and the dosage of the sealing agent is 5-30% of the mass of the bonding component.

2. The anti-settling glass bead for the hot melt type marking paint as claimed in claim 1, wherein the liquid solvent is any one of dioctyl phthalate, dibutyl phthalate, naphthenic oil, industrial white oil, or a mixture of several of them in any proportion.

3. The anti-settling glass bead for hot melt type marking paint as claimed in claim 1 or 2, wherein the boiling point of the liquid solvent is not lower than 100 ℃.

4. The anti-settling glass bead for hot melt type reticle coating according to claim 1, wherein the styrenic thermoplastic elastomer is any one of styrene-butadiene-styrene block copolymer, hydrogenated styrene-butadiene block copolymer, styrene-isoprene-styrene block copolymer, or a mixture of several thereof at any ratio.

5. The preparation method of the anti-settling glass bead for the hot melt type marking paint as claimed in claim 1, which comprises the steps of dissolving the bonding resin and the thermoplastic elastomer in a liquid solvent to obtain a mixed solution with a viscosity of 20-150 mPa · s at 70 ℃ as a bonding component, uniformly dispersing the swelling agent in the bonding component to obtain a bonding component containing the swelling agent, adding the glass bead pretreated by adopting the silane coupling agent in advance, rotating and rolling to enable the silane coupling agent pretreated glass bead to be uniformly wrapped by the bonding component containing the swelling agent, and finally wrapping a layer of sealing agent on the outer layer of the bonding component containing the swelling agent to prepare the anti-settling glass bead for the hot melt type marking paint.

6. The anti-settling glass bead for hot melt type marking paint according to claim 1, wherein the anti-settling glass bead is used as an internal mixing and/or surface scattering glass bead of the hot melt type marking paint.