An anti-slip plastic bottle cap and its preparation method

Abstract

The present invention discloses an anti-slip plastic bottle cap and a preparation method thereof, which relates to the technical field of plastic bottle caps. An anti-slip plastic bottle cap includes a cap body and a protective rubber pad. A plurality of anti-slip grooves are evenly formed on the outer peripheral side of the cap body. The protective rubber pad is tightly sleeved on the outer peripheral side of the cap body, and depressions corresponding to the anti-slip grooves are formed at the positions of the anti-slip grooves. Further, the cap body is injection molded from PET resin, and the protective rubber pad is made by mixing natural rubber and ethylene propylene diene monomer rubber and integrally injection molded with the cap body through a two-color injection molding process. Through the mutual cooperation of the anti-slip grooves on the cap body and the protective rubber pad, not only can the plastic bottle cap be fully stressed and is easier to rotate without slipping, but also the soft protective rubber pad can reduce the potential scratching and indentation feeling on the hand of the user caused by the harder anti-slip grooves, improving the comfort when rotating the plastic bottle cap.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic bottle caps, and particularly to an anti-slip plastic bottle cap and a preparation method thereof. Background Art

[0002] Plastic bottle caps are one of the relatively common plastic products in our daily life, and their main function is to seal the bottle to prevent the beverages in the bottle from deteriorating. Among them, the rotary plastic bottle cap is the most common. The user can rotate the bottle cap, and the bottle cap can be tightened or loosened along the thread.

[0003] Currently, the most common problem with plastic bottle caps during use is that the bottle cap cannot be unscrewed. This is generally because negative pressure is generated inside the bottle, and the bottle cap is tightly pressed against the bottle by atmospheric pressure, greatly increasing the static friction between the bottle cap and the bottle. Coupled with the relatively low surface roughness of the material of general plastic bottle caps, the user is prone to slipping during the actual screwing process. As a result, the friction generated between the user's fingers and the bottle cap is less than the static friction between the bottle cap and the bottle, and at this time, the user cannot unscrew the bottle cap.

[0004] In order to increase the surface roughness of plastic bottle caps and reduce the slipping phenomenon when the user unscrews the bottle cap, traditional designs have been improved from the shape and structure of plastic bottle caps. For example, for a general mineral water bottle cap, several anti-slip stripes are added to the outer peripheral side of the bottle cap to increase the surface roughness of the bottle cap. Although the surface roughness of the plastic bottle cap covered with anti-slip stripes is high, the setting of these anti-slip stripes is generally hard, thin and dense. During long-term storage or transportation, the anti-slip stripes will also be worn or smoothed due to external factors such as aging, collision and extrusion. At this time, not only is the user prone to slipping when unscrewing, but the remaining anti-slip stripes on the surface will also make people feel uncomfortable and even may produce a small amount of burrs and scratch the user's fingers. Summary of the Invention

[0005] In order to improve the anti-slip performance of plastic bottle caps, extend the anti-slip effect of plastic bottle caps, and at the same time improve the touch and comfort of the user when rotating the plastic bottle cap, the present application provides an anti-slip plastic bottle cap and a preparation method thereof.

[0006] In a first aspect, an anti-slip plastic bottle cap provided by the present application adopts the following technical solution:

[0007] An anti-slip plastic bottle cap includes a cap body and a protective rubber pad. The inner surface of the cap body is provided with a tightening thread, and a plurality of anti-slip grooves are evenly opened on the outer peripheral side of the cap body. The protective rubber pad is tightly sleeved on the outer peripheral side of the cap body and forms a depression corresponding to the anti-slip groove at the position of the anti-slip groove;

[0008] Specifically, the cover body is injection-molded from PET resin, and the protective rubber pad is integrally injection-molded with the cover body through a two-color injection molding process by mixing natural rubber and ethylene propylene diene monomer rubber.

[0009] By adopting the above technical solution, the anti-slip grooves provided on the cover body can provide force application points and mortise joints for the plastic bottle cap. Not only can the user apply sufficient force through the protective rubber pad at the position of the anti-slip grooves, so that the plastic bottle cap can be fully stressed and is easier to rotate without slipping, but also the protective rubber pad can be fully tenoned and mortised with the cover body through the anti-slip grooves, and it is not easy to slip with the cover body and fall off the cover body during rotation. Secondly, the soft protective rubber pad covers the surface of the cover body, which can effectively reduce the potential scratching and indentation feeling of the relatively hard anti-slip grooves on the user's hand, and is beneficial to improving the comfort when rotating the plastic bottle cap. In addition, the cover body and the protective rubber pad are integrally formed by a two-color injection molding process, which is beneficial to improving the production efficiency of the plastic bottle cap and reducing the preparation cost.

[0010] Optionally, the cover body (1) is made of the following raw materials in parts by weight:

[0011] 70 - 80 parts of PET resin, 20 - 30 parts of active calcium carbonate, 1.4 - 1.8 parts of antioxidant, 2.5 - 3 parts of silane coupling agent, 1.5 - 2 parts of titanium dioxide, 0.6 - 0.9 parts of pigment filler;

[0012] The protective rubber pad (2) is made of the following raw materials in parts by weight:

[0013] 25 - 30 parts of natural rubber, 20 - 25 parts of ethylene propylene diene monomer rubber, 0.5 - 1 part of sulfur, 1.2 - 1.5 parts of vulcanization accelerator, 1.5 - 2 parts of compatibilizer, 5 - 8 parts of zinc oxide, 1.5 - 2 parts of stearic acid, 1.4 - 1.8 parts of anti-aging agent, 8 - 10 parts of modified white carbon black, 0.5 - 0.75 parts of color masterbatch;

[0014] Wherein the modified white carbon black is specifically white carbon black coated with carbonized starch.

[0015] By adopting the above technical solution, it is beneficial to obtain a cover body and a protective rubber pad with good heat aging performance and anti-slip effect.

[0016] Optionally, the preparation of the modified silica used in the raw materials of the protective rubber pad (2) includes the following steps: Mix corn starch and water in a weight ratio of 1:(8 - 10), heat up to 80 - 83°C and continuously stir and mix for 20 - 30 min. After the corn starch forms a paste, add fumed silica. Among them, the mixing weight ratio of the fumed silica and the corn starch is 1:(0.15 - 0.2). Heat to 84 - 86°C and continue to stir for 20 - 30 min. After heating and drying the moisture, carry out carbonization treatment in an inert environment. After natural cooling, fully crush it to obtain a modified silica coated with carbonized starch.

[0017] By adopting the above technical solution, adding the modified silica pre-coated with carbonized corn starch as the reinforcing filler of the protective rubber pad not only helps to improve the compatibility of the modified silica with natural rubber and ethylene propylene diene monomer (EPDM) rubber, reduce the precipitation of the modified silica from the protective rubber pad, but also helps to improve the wet skid resistance of the protective rubber pad. When the hands of the user and the plastic bottle cap are both wet, it can still have a certain anti-slip effect on the surface feel and is not prone to slipping.

[0018] Optionally, the vulcanization accelerator used in the protective rubber pad is specifically a mixture of N-cyclohexyl-2-benzothiazole sulfenamide and 2-mercaptobenzothiazole, and the weight ratio of N-cyclohexyl-2-benzothiazole sulfenamide to 2-mercaptobenzothiazole is 1:(0.2 - 0.5).

[0019] By adopting the above technical solution, it can effectively improve the vulcanization efficiency of the rubber system in which natural rubber and EPDM rubber are mixed with each other, thereby reducing the pressure vulcanization time of the protective rubber pad in the two-color injection molding process and being beneficial to improving the overall production efficiency of the plastic bottle cap.

[0020] Optionally, the antioxidant used in the protective rubber pad is specifically a mixture of antioxidant RD and antioxidant MB in a weight ratio of 1:(0.5 - 1).

[0021] By adopting the above technical solution, when antioxidant RD and antioxidant MB are used in combination in a weight ratio of 1:(0.5 - 1), due to the complementarity of the action mechanisms of the two antioxidants, a certain synergistic effect can be produced, which not only helps to improve the heat resistance, oxygen resistance, ozone resistance and flexing aging properties of natural rubber and EPDM rubber, but also helps to prevent the fatigue degradation of natural rubber and EPDM rubber, thereby extending the service life of the protective rubber pad.

[0022] Optionally, the pigment filler used in the cap body is inorganic pigment powder, and the masterbatch used in the protective rubber pad is specifically prepared with styrene-butadiene rubber as the carrier and inorganic pigment powder as the dye.

[0023] By adopting the above technical solution, the inorganic pigment has good light resistance, heat resistance, weather resistance, and solvent resistance. It not only has strong dyeing and covering properties, but also has low migration. Compared with the use of organic pigments, the use of non-toxic inorganic pigments is conducive to improving the long-term color of plastic bottle caps, so that the cap body and protective rubber pad can maintain rich colors for a long time, and can also prevent the cap body and protective rubber pad from fading, color migration, color powder precipitation and other problems.

[0024] Optionally, the tightening thread on the inner surface of the cap body is specifically a right-handed thread that tightens the plastic bottle cap clockwise, and the anti-slip groove is arranged to extend obliquely from top to bottom in a counterclockwise direction.

[0025] By adopting the above technical solution, when the user loosens the plastic bottle cap, the protective rubber pad has a tendency to slide downward along the anti-slip groove. At this time, the user can feel that the protective rubber pad is getting tighter and tighter towards the bottom of the cap body, and it is not easy to fall out. At the same time, the user can also give the cap body a counterclockwise and upward thrust through the protective rubber pad and the anti-slip groove, which is conducive to loosening the plastic bottle cap.

[0026] Optionally, the depth of the anti-slip groove on the cover body is 1-1.2 mm, and the thickness of the protective rubber pad is about 0.8-1 mm.

[0027] By adopting the above technical scheme, the anti-slip groove with a certain depth can provide sufficient force points for the cover body, which is conducive to the cover body being fully stressed and rotated, and the thinner protective rubber pad can not only tightly cover the surface of the cover body, but also form a depression corresponding to the anti-slip groove at the position of the anti-slip groove, which is conducive to the user to fully apply force on the anti-slip groove through the protective rubber pad, but also can reduce the potential scratches and roughness of the harder anti-slip groove on the user's hands to a certain extent, which is conducive to improving the comfort when turning the plastic bottle cap.

[0028] In the second aspect, the present application provides a method for preparing a non-slip plastic bottle cap using the following technical solution:

[0029] A method for preparing a non-slip plastic bottle cap comprises the following steps:

[0030] S1, PET resin, activated calcium carbonate, titanium dioxide, antioxidant, silane coupling agent and color filler are fully mixed in proportion, and melt-extruded and granulated after drying to obtain a cover body injection molding material, and then the cover body injection molding material is added to the injection molding machine A of the two-color injection molding machine; natural rubber, EPDM rubber, compatibilizer, zinc oxide, stearic acid, antioxidant, modified white carbon black and masterbatch are fully mixed in proportion, and then extruded and granulated after mixing to obtain a mixed rubber, and then the mixed rubber, sulfur and vulcanization accelerator are fully mixed in proportion to obtain a rubber cushion injection molding material, and then the rubber cushion injection molding material is added to the injection molding machine B of the two-color injection molding machine;

[0031] S2. First, perform a primary injection molding using injection molding machine A, inject the molten cover body injection material into the mold, then perform a primary pressure holding and cooling. After the melt in the mold is basically cooled and solidified, a semi-finished cover body is obtained.

[0032] S3. Flip the mold, perform a secondary injection molding using injection molding machine B, inject the molten gasket injection material into the mold, then perform a secondary pressure holding and cooling. After the melt in the mold is fully cooled and solidified, open the mold and take out the workpiece from the mold to obtain a non-slip plastic bottle cap.

[0033] By adopting the above technical solution, the cover body and the protective gasket are integrally formed by using a two-color injection molding process, which can not only reduce the process steps of combining the cover body and the protective gasket, but also improve the combination accuracy between the cover body and the protective gasket, which is beneficial to improving the molding efficiency of the plastic bottle cap and reducing the preparation cost.

[0034] Optionally, in step S2, the process parameters of the primary injection molding are: mold temperature 120 - 140 °C, melt temperature 270 - 280 °C, injection pressure 140 - 150 MPa; the process parameters of the primary pressure holding are: pressure holding pressure is 75% - 80% of the injection pressure, pressure holding time 10 - 15 s.

[0035] In step S3, the process parameters of the secondary injection molding are: mold temperature 80 - 120 °C, melt temperature 190 - 200 °C, injection pressure 140 - 150 MPa; the process parameters of the secondary pressure holding are: pressure holding pressure is 75% - 80% of the injection pressure, pressure holding time 2.5 - 3 min.

[0036] By adopting the above technical solution, it is beneficial to obtain a cover body and a protective gasket with a smooth and flat surface and uniform performance.

[0037] In summary, the technical solution of the present application has at least any one of the following beneficial effects.

[0038] 1. Through the mutual cooperation of the anti-slip grooves on the cover body and the protective gasket, not only can the plastic bottle cap be fully stressed and is easier to rotate without slipping, but also the soft protective gasket can slow down the potential scratching and indentation feeling of the harder anti-slip grooves on the user's hand, improving the comfort when rotating the plastic bottle cap.

[0039] 2. By adding modified silica white pre-coated with carbonized corn starch as a reinforcing filler for the protective gasket, it is not only beneficial to reduce the precipitation of modified silica white from the protective gasket, but also beneficial to improve the anti-wet skid performance of the protective gasket. When the user's hands and the plastic bottle cap are both wet, it can still have a certain anti-slip effect on the surface feel and is not easy to slip.

[0040] 3. By cooperating with the tightening thread of the right-handed thread to set the extending direction of the anti-slip groove, the anti-slip groove extends obliquely downward along the counterclockwise direction from top to bottom. When the user unscrews the plastic bottle cap, the protective gasket has a tendency to slide downward along the anti-slip groove. At this time, the user will feel that the protective gasket becomes tighter and tighter in the direction of the bottom of the cap during unscrewing, and it is not easy to fall out. At the same time, the user can also apply a pushing force to the cap along the counterclockwise direction and obliquely upward through the protective gasket and the anti-slip groove, which is beneficial to unscrewing the plastic bottle cap.

[0041] 4. By adopting the two-color injection molding process to integrally form the cap body and the protective gasket, it is beneficial to improve the combination accuracy between the cap body and the protective gasket, and also beneficial to improve the molding efficiency of the plastic bottle cap and reduce the preparation cost. Description of the Drawings

[0042] Figure 1 It is a schematic structural view of an anti-slip plastic bottle cap in Embodiment 1 of the present application.

[0043] Figure 2 It is a cross-sectional view of an anti-slip plastic bottle cap in Embodiment 1 of the present application.

[0044] Figure 3 It is a schematic structural view of a plastic bottle cap in Comparative Example 1 of the present application.

[0045] Figure 4 It is a cross-sectional view of a plastic bottle cap in Comparative Example 1 of the present application.

[0046] Figure 5 It is a schematic structural view of a plastic bottle cap in Comparative Example 2 of the present application.

[0047] Figure 6 It is a schematic structural view of a plastic bottle cap in Comparative Example 3 of the present application.

[0048] Description of the Reference Numerals:

[0049] 1. Cap body; 11. Tightening thread; 12. Anti-slip groove; 2. Protective gasket. Detailed Embodiments

[0050] The following further describes the present application in detail in conjunction with the attached Figure 1-6 preparation examples, embodiments and comparative examples.

[0051] Preparation Examples

[0052]

Preparation Example 1

[0053] A modified silica, comprising the following preparation steps:

[0054] Mix 400 g of corn starch and water in a weight ratio of 1:8, heat up to 80 °C and continuously stir and mix for 30 min. After the corn starch forms a paste, add 2 kg of fumed silica, heat to 84 °C and continue stirring for 30 min, further heat up to 105 °C and dry the moisture, then place it in an oven at 200 °C and carry out carbonization treatment for 6 h in a nitrogen environment. After it cools naturally, fully crush it to obtain a fumed silica coated with carbonized starch.

[0055]

Preparation Example 2

[0056] A modified fumed silica, comprising the following preparation steps:

[0057] Mix 300 g of corn starch and water in a weight ratio of 1:10, heat up to 83 °C and continuously stir and mix for 20 min. After the corn starch forms a paste, add 2 kg of fumed silica, heat to 86 °C and continue stirring for 20 min, then further heat up to 105 °C and dry the moisture, then place it in an oven at 240 °C and carry out carbonization treatment for 3 h in a nitrogen environment. After it cools naturally, fully crush it to obtain a fumed silica coated with carbonized starch.

[0058] Examples

[0059]

Example 1

[0060] An anti-slip plastic bottle cap, referring to Figure 1 and Figure 2 , includes a cap body 1 and a protective rubber pad 2. The inner surface of the cap body 1 is provided with a screwing thread 11, and a plurality of anti-slip grooves 12 are evenly opened on the outer peripheral side of the cap body 1. The protective rubber pad 2 is sleeved on the outer peripheral side of the cap body 1 and closely adheres to the outer surface of the anti-slip grooves 12. Specifically, in this embodiment, the screwing thread 11 is a right-handed thread for screwing the plastic bottle cap clockwise, the anti-slip grooves 12 are inclined and extended downward along the counterclockwise direction from top to bottom, and the depth of the anti-slip grooves 12 is set to 1 mm, and the formed thickness of the protective rubber pad 2 is about 0.8 mm. Since the protective rubber pad 2 closely adheres to the outer surface of the anti-slip grooves 12, depressions corresponding to the anti-slip grooves 12 are formed at the positions of the anti-slip grooves 12.

[0061] In this embodiment, the cap body 1 is made by mixing the following raw materials and injection molding:

[0062] 8 kg of PET resin, 2 kg of active calcium carbonate, 0.14 kg of antioxidant, 0.3 kg of silane coupling agent KH570, 0.2 kg of titanium dioxide, and 0.06 kg of ultramarine.

[0063] Among them, the antioxidant is specifically a compound mixture of antioxidant 1010 and antioxidant 168 in a weight ratio of 1:1, that is, it contains 0.07 kg of antioxidant 1010 and 0.07 kg of antioxidant 168.

[0064] In this embodiment, the protective rubber pad 2 is made by mixing the following raw materials and injection molding: 3 kg of natural rubber, 2 kg of ethylene propylene diene monomer rubber, 0.08 kg of sulfur, 0.15 kg of vulcanization accelerator, 0.2 kg of compatibilizer, 0.5 kg of zinc oxide, 0.15 kg of stearic acid, 0.18 kg of anti-aging agent, 1 kg of modified silica white, and 0.075 kg of masterbatch.

[0065] Among them, the vulcanization accelerator is specifically a compound mixture of N-cyclohexyl-2-benzothiazole sulfenamide and 2-mercaptobenzothiazole in a weight ratio of 1:0.5, that is, it contains 0.1 kg of N-cyclohexyl-2-benzothiazole sulfenamide and 0.05 kg of 2-mercaptobenzothiazole. The compatibilizer is specifically maleic anhydride grafted ethylene propylene diene monomer rubber. The anti-aging agent is specifically a compound mixture of anti-aging agent RD and anti-aging agent MB in a weight ratio of 1:0.5, that is, it contains 0.12 kg of anti-aging agent RD and 0.06 kg of anti-aging agent MB. The modified silica white is specifically a kind of modified silica white prepared in

Preparation Example 1

[0066] A preparation method of a non-slip plastic bottle cap includes the following steps:

[0067] S1. Sufficiently mix PET resin, active calcium carbonate, titanium dioxide, antioxidant, silane coupling agent KH570, and ultramarine in proportion, dry and then melt and extrude into pellets to obtain the injection molding material for the cap body 1, and then add it to injection molding machine A of a two-color injection molding machine; sufficiently mix natural rubber, ethylene propylene diene monomer rubber, compatibilizer, zinc oxide, stearic acid, anti-aging agent, modified silica white, and masterbatch in proportion, then knead and extrude into pellets to obtain a kneaded rubber, and then sufficiently mix the kneaded rubber, sulfur, and vulcanization accelerator in proportion to obtain the injection molding material for the rubber pad, and then add it to injection molding machine B of the two-color injection molding machine.

[0068] S2. First, perform the first injection molding through injection molding machine A, inject the molten injection molding material for the cap body 1 into the mold, where the mold temperature is set at 120 °C, the melt temperature is 270 °C, and the injection pressure is 140 MPa. Then perform the first pressure holding and cooling, where the pressure holding pressure is 80% of the injection pressure, the pressure holding time is 10 s, and the cooling time is 10 s. Wait until the melt in the mold is basically cooled and solidified to obtain the semi-finished product of the cap body 1.

[0069] S3. Flip the mold and perform secondary injection molding through injection molding machine B. Inject molten gasket injection plastic into the mold. The mold temperature is reduced to 80 °C, the melt temperature is 190 °C, and the injection pressure is 120 MPa. Then perform secondary pressure holding and cooling. The pressure holding pressure is 80% of the injection pressure, the pressure holding time is 3 min, and the cooling time is 10 s. After the melt in the mold is fully cooled and solidified, open the mold and take out the workpiece from the mold to obtain a non-slip plastic bottle cap.

[0070]

Example 2

[0071] A non-slip plastic bottle cap is different from that in

Example 1

[0072] In this embodiment, the cap body 1 is made by mixing the following raw materials and injection molding:

[0073] 7 kg of PET resin, 3 kg of active calcium carbonate, 0.2 kg of antioxidant, 0.25 kg of silane coupling agent KH570, 0.15 kg of titanium dioxide, and 0.09 kg of ultramarine.

[0074] Among them, the antioxidant is specifically a compound mixture of antioxidant 1010 and antioxidant 168 in a weight ratio of 1:1.5, that is, it contains 0.08 kg of antioxidant 1010 and 0.12 kg of antioxidant 168.

[0075] In this embodiment, the protective gasket 2 is made by mixing the following raw materials and injection molding:

[0076] 2.5 kg of natural rubber, 2.5 kg of ethylene propylene diene monomer rubber, 0.1 kg of sulfur, 0.12 kg of vulcanization accelerator, 0.15 kg of compatibilizer, 0.8 kg of zinc oxide, 0.2 kg of stearic acid, 0.14 kg of antioxidant, 0.8 kg of modified silica white, and 0.05 kg of color masterbatch.

[0077] Among them, the vulcanization accelerator is specifically a compound mixture of N-cyclohexyl-2-benzothiazole sulfenamide and 2-mercaptobenzothiazole in a weight ratio of 1:0.2, that is, it contains 0.1 kg of N-cyclohexyl-2-benzothiazole sulfenamide and 0.02 kg of 2-mercaptobenzothiazole. The compatibilizer is specifically maleic anhydride grafted ethylene propylene diene monomer rubber. The antioxidant is specifically a compound mixture of antioxidant RD and antioxidant MB in a weight ratio of 1:1, that is, it contains 0.07 kg of antioxidant RD and 0.07 kg of antioxidant MB. The modified silica white is specifically a kind of modified silica white prepared in

Preparation Example 2

[0078] A preparation method of a non-slip plastic bottle cap is different from that in

Example 1

[0079] Specifically, in step S2, the process parameters for the first injection molding are as follows: the mold temperature is set at 140 °C, the melt temperature is 280 °C, and the injection pressure is 150 MPa. The process parameters for the first pressure holding are as follows: the pressure holding pressure is 75% of the injection pressure, the pressure holding time is 15 s, and the cooling time is 10 s.

[0080] Specifically, in step S3, the process parameters for the first injection molding are as follows: the mold temperature is reduced to 100 °C, the melt temperature is 200 °C, and the injection pressure is 130 MPa. The process parameters for the first pressure holding are as follows: the pressure holding pressure is 75% of the injection pressure, the pressure holding time is 2.5 min, and the cooling time is 10 s.

[0081] Comparative Example

[0082]

Comparative Example 1

[0083] A plastic bottle cap, referring to Figure 3 and Figure 4 , is different from

Example 1

[0084]

Comparative Example 2

[0085] A plastic bottle cap, referring to Figure 5 , is different from

Example 1

[0086]

Comparative Example 3

[0087] A plastic bottle cap, referring to Figure 6 , is different from

Example 1

[0088] In this comparative example, the anti-slip groove 12 extends in the vertical direction.

[0089]

Comparative Example 4

[0090] An anti-slip plastic bottle cap is different from

Example 1

[0091] In this comparative example, no anti-aging agent is added to the protective rubber pad 2.

[0092]

Comparative Example 5

[0093] An anti-slip plastic bottle cap is different from

Example 1

[0094] In this comparative example, the modified white carbon black in the protective rubber pad 2 is replaced with ordinary fumed white carbon black in equal amount.

[0095] Performance test data

[0096] 1. Anti-slip feel test of the bottle cap: The tester first tightly screws the plastic bottle caps prepared in each example and comparative example onto the corresponding bottle bodies with a torque force of 3.0 N·m, and then the tester unscrews the plastic bottle caps respectively when the plastic bottle caps and both hands are dry or wet, and records the subjective feelings when turning to completely unscrew the plastic bottle caps of each example and comparative example.

[0097] 2. Heat aging test of the protective gasket: First, according to the provisions of cycle number 1 in method A of table 3 in "GB / T 16422.2-2014 Plastics - Methods of exposure to laboratory light sources", an automatic cycle exposure test is carried out, and the exposure time is 1000 h. The protective gasket of the plastic bottle cap needs to face the side of the xenon lamp light source. After aging, observe the surface state of the protective gasket, and record the appearance and feel changes of the protective gaskets of each example and comparative example after xenon lamp aging.

[0098]

[0099]

[0100] According to Example 1 and Comparative Examples 1-2 and combined with the data in Table 1, it can be seen that the anti-slip grooves 12 opened on the cap body 1 can provide a force application point and a mortise joint point for the plastic bottle cap. Not only can the user apply force fully through the protective gasket 2 at the position of the anti-slip grooves 12, so that the plastic bottle cap can be fully stressed and is easier to rotate, but also the protective gasket 2 can be fully tenoned and mortised with the cap body 1 through the anti-slip grooves 12. When rotating, the protective gasket 2 is not easy to slip with the cap body 1 and is not easy to fall off the cap body 1. Secondly, the soft protective gasket 2 is coated on the surface of the cap body 1. When the user rotates the plastic bottle cap, the protective gasket 2 can effectively reduce the potential scratching and indentation feeling of the harder anti-slip grooves 12 on the user's hand, greatly improving the comfort of rotating the plastic bottle cap.

[0101] According to Example 1 and Comparative Example 3 in combination with the data in Table 1, it can be seen that when the anti-slip groove 12 on the cover body 1 extends along an inclined direction, compared with when it extends along the vertical direction, the protective rubber pad 2 is less likely to separate from or fall out of the cover body 1 during rotation. This may be because the plastic bottle caps in Example 1 and Comparative Example 3 both use right-handed threads, that is, when the user wants to loosen the plastic bottle cap, it needs to be rotated counterclockwise. And the anti-slip groove 12 set in Example 1 extends obliquely downward along the counterclockwise direction. Thus, when the user loosens the plastic bottle cap, the protective rubber pad 2 has a tendency to slide downward along the anti-slip groove 12. At this time, it will be felt that the protective rubber pad 2 is tightened more and more towards the bottom of the cover body 1 and is not easy to fall out. At the same time, the user can also give the cover body 1 a thrust along the counterclockwise direction and obliquely upward through the protective rubber pad 2 and the anti-slip groove 12, which is also beneficial to loosening the plastic bottle cap. However, the anti-slip groove 12 in Comparative Example 3 extends along the vertical direction and cannot give the protective rubber pad 2 a tendency to slide downward. Coupled with the fact that when the user loosens the plastic bottle cap, there is often a force applied to move the plastic bottle cap away from the plastic bottle. Therefore, it will be felt in terms of hand feeling that the protective rubber pad 2 is easy to fall out of the cover body 1 along the anti-slip groove 12.

[0102] According to Example 1 and Comparative Example 4 in combination with the data in Table 1, it can be seen that when an anti-aging agent is added to the protective rubber pad 2, it can effectively improve the heat aging resistance of the protective rubber pad 2 and extend the service life of the protective rubber pad 2. And the protective rubber pad 2 can also play a certain protective role for the cover body 1 and the anti-slip groove 12 on the cover body 1, and is also beneficial to extending the anti-slip effect of the plastic bottle cap.

[0103] According to Example 1 and Comparative Example 5 in combination with the data in Table 1, it can be seen that compared with Example 1, the surface of the protective rubber pad 2 added with ordinary fumed silica in Comparative Example 5 is relatively slippery and prone to slipping when the hands of the user and the plastic bottle cap are both wet. And after long-term aging, a lot of powder precipitates on the surface, and the aging effect is not ideal. This may be because the surface of fumed silica has more hydroxyl groups, and natural rubber and ethylene propylene diene monomer rubber, which are the matrix resins of the protective rubber pad 2, are both non-polar rubbers. The compatibility between ordinary fumed silica and rubber is poor. Not only is it easy to separate and precipitate after aging, but it may also cause the protective rubber pad 2 to have a water absorption phenomenon and form a molecular adsorption layer, reducing the surface roughness of the protective rubber pad 2. Thus, it will be felt in terms of hand feeling that the surface of the protective rubber pad 2 is relatively wet and slippery. After being coated with corn starch and then carbonized, the surface polarity of the modified fumed silica is greatly reduced, which not only improves the compatibility between the modified fumed silica and rubber and is not easy to precipitate after long-term use, but also reduces the water absorption and wet-slipping problems caused by hydroxyl groups, which is beneficial to improving the anti-wet-slip performance of the protective rubber pad 2.

[0104] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this specific embodiment that do not contribute creatively as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A non-slip plastic bottle cap, characterized by: The invention comprises a cover body (1) and a protective rubber pad (2) which are integrally molded by a two-color injection molding process, wherein the inner surface of the cover body (1) is provided with a tightening thread (11), and the tightening thread (11) is specifically a right-hand thread for tightening the bottle cap in a clockwise direction; a plurality of anti-skid grooves (12) with a depth of 1-1.2 mm are evenly opened on the outer peripheral side of the cover body (1), and the anti-skid grooves (12) are arranged to extend obliquely from top to bottom in a counterclockwise direction; the protective rubber pad (2) is tightly sleeved on the outer peripheral side of the cover body (1), and the thickness of the protective rubber pad (2) is 0.8-1 mm; the protective rubber pad (2) forms a depression corresponding to the anti-skid groove (12) at the position of the anti-skid groove (12), and is fully connected to the cover body (1) by mortise and tenon joints through the anti-skid groove (12); The cover body (1) is made of the following raw materials in parts by weight: PET resin 70-80 parts, active calcium carbonate 20-30 parts, antioxidant 1.4-1.8 parts, silane coupling agent 2.5-3 parts, titanium dioxide 1.5-2 parts, color filler 0.6-0.9 parts; The protective rubber pad (2) is made of the following raw materials in parts by weight: 25-30 parts of natural rubber, 20-25 parts of EPDM rubber, 0.5-1 parts of sulfur, 1.2-1.5 parts of vulcanization accelerator, 1.5-2 parts of compatibilizer, 5-8 parts of zinc oxide, 1.5-2 parts of stearic acid, 1.4-1.8 parts of antioxidant, 8-10 parts of modified silica, 0.5-0.75 parts of masterbatch; The modified silica is specifically carbonized starch-coated silica that has been carbonized at 200-240°C.

2. The anti-slip plastic bottle cap according to claim 1, characterized in that: The preparation of the modified white carbon black used in the raw material of the protective rubber pad (2) comprises the following steps: Corn starch and water are mixed in a weight ratio of 1: (8-10), heated to 80-83°C and continuously stirred for 20-30 minutes, and fumed silica is added after the corn starch forms a paste, wherein the mixing weight ratio of the fumed silica to the corn starch is 1: (0.15-0.2), heated to 84-86°C and continuously stirred for 20-30 minutes, heated to dry the water, and then carbonized in an inert environment, and then fully crushed after naturally cooling to obtain a carbonized starch-coated modified silica.

3. The anti-slip plastic bottle cap according to claim 1, characterized in that: The vulcanization accelerator used in the protective rubber pad (2) is specifically a mixture of N-cyclohexyl-2-benzothiazole sulfenamide and 2-mercaptobenzothiazole, and the weight ratio of the N-cyclohexyl-2-benzothiazole sulfenamide to the 2-mercaptobenzothiazole is 1:(0.2-0.5).

4. The anti-slip plastic bottle cap according to claim 1, characterized in that: The antioxidant used in the protective rubber pad (2) is specifically a mixture of antioxidant RD and antioxidant MB in a weight ratio of 1:(0.5-1).

5. The anti-slip plastic bottle cap according to claim 1, characterized in that: The pigment filler used in the cover body (1) is inorganic pigment powder, and the masterbatch used in the protective rubber pad (2) is specifically made of styrene-butadiene rubber as a carrier and inorganic pigment powder as a dye.

6. The method for preparing a non-slip plastic bottle cap according to any one of claims 1 to 5, characterized in that: The method comprises the following preparation steps: S1, PET resin, activated calcium carbonate, titanium dioxide, antioxidant, silane coupling agent and pigment filler are fully mixed in proportion, and after drying, melt extrusion granulation is performed to obtain a cover body (1) injection molding material, and then the cover body (1) injection molding material is added to the injection molding machine A of the two-color injection molding machine; natural rubber, EPDM rubber, compatibilizer, zinc oxide, stearic acid, antioxidant, modified white carbon black and masterbatch are fully mixed in proportion, and then extrusion granulation is performed after mixing to obtain a mixed rubber, and then the mixed rubber, sulfur and vulcanization accelerator are fully mixed in proportion to obtain a rubber pad injection molding material, and then the rubber pad injection molding material is added to the injection molding machine B of the two-color injection molding machine; S2, firstly perform an injection molding process using the injection molding machine A to inject the molten injection material of the cover body (1) into the mold, then perform a pressure holding and cooling process, and wait until the melt in the mold is sufficiently cooled and shaped to obtain a semi-finished cover body (1); S3, flip the mold, and perform secondary injection molding through injection molding machine B, inject molten rubber pad injection plastic into the mold, and then perform secondary pressure holding and cooling. After the melt in the mold is fully cooled and shaped, open the mold and take out the workpiece from the mold to obtain a non-slip plastic bottle cap.

7. The method for preparing a non-slip plastic bottle cap according to claim 6, characterized in that: In step S2, the process parameters of the one-shot injection molding are: mold temperature 120-140°C, melt temperature 270-280°C, injection pressure 140-150MPa; the process parameters of the one-shot holding pressure are: holding pressure is 75%-80% of the injection pressure, and holding time is 10-15s; In step S3, the process parameters of the secondary injection molding are: mold temperature 80-120°C, melt temperature 190-200°C, injection pressure 140-150MPa; the process parameters of the secondary holding pressure are: holding pressure is 75%-80% of the injection pressure, and holding time is 2.5-3min.

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