An activator for improving the adhesion of yarn to rubber and use thereof

Abstract

The present application belongs to the field of activators, and particularly relates to an activator for improving the adhesion of yarn and rubber and the use thereof. The activator is composed of 38-68wt% component A: alkyl silane, 24.2-41.2wt% component B: fatty acid polyoxyethylene ester, 5.5-13wt% component C: triethylene glycol dimethyl ether and 0.6-4.7wt% component D: alkyl phenol polyoxyethylene ether. The activator of the present application can improve the adhesion of yarn and rubber.

Description

Technical Field

[0001] This invention belongs to the field of activators, specifically relating to an activator for improving the adhesion between yarn and rubber and its uses. Background Technology

[0002] In the evaluation of the adhesion strength of known yarn-rubber composites, the yarn types are mostly conventional industrial yarns such as polyester / nylon, and the rubber types are mainly butadiene rubber, styrene-butadiene rubber, and butyl rubber. The rubber needs to be refined and reshaped before it can be used for sample preparation, and it is commonly used in tire cord fabric, canvas, and fire hoses. Bonding yarn and rubber usually requires a traditional two-bath phenolic resin impregnation system followed by a vulcanization process. The one-bath impregnation process requires the addition of adhesion promoters, and the ammonia gas generated during the mixing process can affect the environment and human health. With the development of industrial technology, activators are widely used in the bonding process of yarn-rubber composites. Although the use of activators has replaced the one-bath impregnation process and reduced production costs, the adhesion strength of the yarn-rubber composites is not ideal and cannot meet the application specifications of downstream products.

[0003] Therefore, we developed an activator formulation that can enhance the adhesion between yarn and rubber to meet the application requirements of downstream products. Summary of the Invention

[0004] The technical problem to be solved by this invention is to develop an activator that improves the adhesion between yarn and rubber and its application, which eliminates the need for a one-bath impregnation process, reduces the production process, and lowers production costs.

[0005] To achieve the above objectives, the first aspect of the present invention adopts the following scheme: an activator for improving the adhesion between yarn and rubber, said activator being composed of 38-68 wt% component A: alkylsilane, 24.2-41.2 wt% component B: fatty acid polyoxyethylene ester, 5.5-13 wt% component C: triethylene glycol dimethyl ether, and 0.6-4.7 wt% component D: alkylphenol polyoxyethylene ether.

[0006] In a preferred embodiment, component A is at least one of [8-(epoxypropyloxy)-n-octyl]trimethoxysilane, γ-(2,3-epoxypropyloxy)propyltrimethoxysilane, or 3-glycidyl etheroxypropyltriethoxysilane.

[0007] Furthermore, the amount of component A (alkylsilane) added is 56 wt%, the amount of component B (fatty acid polyoxyethylene ester) added is 30.2 wt%, the amount of component C (triethylene glycol dimethyl ether) added is 10 wt%, and the amount of component D (alkylphenol polyoxyethylene ether) added is 3.8 wt%.

[0008] A second aspect of the present invention is to provide a method for preparing the aforementioned activator, wherein components A, B, C and D are thoroughly mixed at room temperature to obtain the activator.

[0009] A third aspect of the present invention discloses a method for improving the adhesion between yarn and rubber using the aforementioned activator, comprising yarn oiling activation, yarn aging, impregnation and vulcanization processes; wherein the yarn is high-modulus, low-shrinkage polyester industrial yarn with a fineness of 800D-1500D.

[0010] In a preferred embodiment, the spinning oiling rate is 0.25-0.35%, where oiling refers to the addition of an activator.

[0011] Furthermore, heat treatment is employed during aging, with an aging temperature of 60–80°C and an aging time of 24–72 hours. The impregnation process is a single impregnation.

[0012] A fourth aspect of the present invention is to provide the use of the aforementioned activator in improving the adhesion between yarn and rubber, and the use of the aforementioned preparation method in improving the adhesion between yarn and rubber.

[0013] Compared with the prior art, the present invention has the following beneficial effects: the hydroxyl groups on the alkylsilane increase the adhesion between the hydroxyl groups and the active components on the rubber, and the hydroxyl groups and the active components of the impregnation undergo an aldol condensation reaction, which promotes the adhesion between the rubber and the yarn.

[0014] Alkylsilane, as an activator, completely replaces epoxy resin for the first time. Together with fatty acid polyoxyethylene ester, triethylene glycol dimethyl ether, and alkylphenol polyoxyethylene ether, the four components improve the adhesion between yarn and rubber. Detailed Implementation

[0015] To make the technical problems, solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0016] This invention discloses an activator that enhances the adhesion between yarn and rubber, comprising component A (alkylsilane) + component B (fatty acid polyoxyethylene ester) + component C (triethylene glycol dimethyl ether) + component D (alkylphenol polyoxyethylene ether). Components A, B, C, and D are all commercially available.

[0017] This invention also discloses a method for improving the adhesion between yarn and rubber using an activator, comprising the following steps:

[0018] (1) Oiling and activating the yarn: After spinning on the TMT machine, oil is applied before winding. In the oiling process, oil is applied by the injection pump nozzle, and the oiling rate is set to 0.25-0.35% (activator formula); (2) After winding, yarn aging is carried out: After spinning on the TMT machine, yarn needs to be aged in a constant temperature chamber. The aging temperature and time are 60-80℃ and 24-72h; (3) Impregnation: After twisting, the yarn is impregnated with RFL glue solution for 195s. Because the modulus and polarity difference between fiber (yarn) and rubber is very large, the adhesion between untreated fiber and rubber is generally low. Chemical bonding is the result of the formation and action of chemical bonds, which plays a key role in the bonding between the skeleton material and T rubber. This bonding is mainly produced by the formation of a macromolecular network between RFL glue solution (resorcinol + formaldehyde (catalyst: ammonia water) → resorcinol resin solution + latex → impregnation solution RFL, which is commercially available) and rubber. Under certain temperature conditions, rubber begins to soften, and various chemical components in the rubber become active, partially diffusing and penetrating to the fiber surface. These chemical substances react with RFL to form a macromolecular network structure, and bond the fiber to the rubber through chemical adhesion. After surface activation treatment, polyester fiber reacts chemically with RFL adhesive, and then crosslinks with styrene-butadiene rubber during the vulcanization stage; (4) Vulcanization process: Set the parameters of the flat vulcanizing machine to 150~165℃, 3.2~3.7MPa, 16~24min or 150~165℃, 115~145KN, 16~24min. After the temperature stabilizes, place the mold on the vulcanizing machine for vulcanization molding. After vulcanization molding, it can be used as tire cord; (5) Peel force and pull-out force test, Peel force value: Cut the formed sample. For raw yarn ≤1670dtex, cut one strand from each side and keep five strands in the middle for testing; for raw yarn ≥1670dtex, cut two strands from each side and keep three strands in the middle for testing. Pull-out force value test: Cut off the edge part of the cooled sample and finally trim it into an "H" shape with yarn shears. Five parallel samples can be cut from each cord. Place the sample on the fixture. Before testing the first sample, the gauge length is zeroed. Before testing each sample, the load needs to be zeroed. Then the test begins.

[0019] The present invention is further illustrated below through specific embodiments. In the following embodiments and comparative examples, the vulcanization process parameters are: 160℃, 135KN, 20min. Unless otherwise specified, the yarn properties are: linear density (dtex): 1120, linear density CV (%): 1.40, breaking strength (N): 76.0, breaking strength (cN / dtex): 7.00, breaking strength CV (%): 3.00, breaking elongation (%): 13.0, breaking elongation CV (%): 8.0, medium elongation (cN / dtex / %): 5.8, dry heat (177℃*10min*0.05) (cN / dtex / %): 2.60, DSI: 8.4, network density (crochet method) (nodes / m): 6.

[0020] Example 1

[0021] The preparation of the activator includes the following steps:

[0022] 1. Mix the activator formulation components A (alkylsilane, 38-68 wt%), B (fatty acid polyoxyethylene ester, 24.2-41.2 wt%), C (triethylene glycol dimethyl ether, 5.5-13 wt%), and D (alkylphenol polyoxyethylene ether, 0.6-4.7 wt%) evenly at room temperature.

[0023] 2. Change the type of component A in step 1 to [8-(epoxypropyloxy)-n-octyl]trimethoxysilane, γ-(2,3-epoxypropyloxy)propyltrimethoxysilane and 3-glycidyl etheroxypropyltriethoxysilane. The contents of components A, B, C and D are 56%, 30.2%, 10% and 3.8% respectively, to obtain new formulations, which are denoted as formulations E, F and G respectively.

[0024] All component contents mentioned in this article are mass fractions.

[0025] Example 2

[0026] This invention discloses a method for improving the adhesion properties of yarn to rubber using an activator formulation, comprising the following steps:

[0027] (1) Activator formulations E, F and G were used in the spinning process, and the oiling rate was set to 0.31%;

[0028] (2) The aging temperature and time of the yarn were 75℃ and 48h, respectively;

[0029] (3) Molded through impregnation and vulcanization processes;

[0030] (4) The extraction force and peel force were tested separately. The specific test results are shown in the table below:

[0031] Table 1. Effects of activator formulations E, F, and G on the adhesion between yarn and rubber.

[0032] Activator formulation E F G Extraction force (N) 166.01 182.68 162.84 Peel force (N) 96.93 115.82 89.17

[0033] As shown in Table 1, activator formulation F has better pull-out force and peel force values.

[0034] Example 3

[0035] This invention discloses a method for improving the adhesion properties of yarn to rubber using an activator formulation, comprising the following steps:

[0036] (1) The activator formulation F was used in the spinning process. The contents of component A were 38%, 44%, 50%, 56%, 62% and 68%, respectively, while the contents of components C and D remained unchanged. The contents of component A+B were kept at 86.2%, and the oiling rate was set at 0.31%.

[0037] (2) The aging temperature and time of the yarn were 75℃ and 48h, respectively;

[0038] (3) Molded through impregnation and vulcanization processes;

[0039] (4) The extraction force and peel force were tested separately. The specific test results are shown in the table below:

[0040] Table 2. Effect of component A content in activator F formulation on the adhesion between yarn and rubber.

[0041]

[0042] Table 2 shows that when the content of component A in the activator F formulation is 56%, it exhibits better pull-out force and peel force values. Furthermore, the content of component A in the activator F formulation has a significant impact on the pull-out force and peel force values.

[0043] Example 4

[0044] This invention discloses a method for improving the adhesion properties of yarn to rubber using an activator formulation, comprising the following steps:

[0045] (1) The activator formulation F was used in the spinning process. The contents of component B were 24.2%, 27.2%, 30.2%, 33.2%, 36.2% and 41.2%, respectively. The contents of components C and D remained unchanged, so that the contents of component A+B were kept at 86.2%, and the oiling rate was set at 0.31%.

[0046] (2) The aging temperature and time of the yarn were 75℃ and 48h, respectively;

[0047] (3) Molded through impregnation and vulcanization processes;

[0048] (4) The extraction force and peel force were tested separately. The specific test results are shown in the table below:

[0049] Table 3. Effect of component B content in activator F formulation on the adhesion between yarn and rubber.

[0050]

[0051] Table 3 shows that when the content of component B in the activator F formulation is 30.2%, it exhibits better pull-out force and peel force values. Furthermore, the content of component B in the activator F formulation has a significant impact on the pull-out force and peel force values.

[0052] Example 5

[0053] This invention discloses a method for improving the adhesion properties of yarn to rubber using an activator formulation, comprising the following steps:

[0054] (1) The activator formulation F was used in the spinning process. The contents of component C were 5.5%, 7.0%, 8.5%, 10%, 11.5% and 13%, respectively. The contents of components A and B remained unchanged, so that the contents of component C+D were kept at 13.8%, and the oiling rate was set at 0.31%.

[0055] (2) The aging temperature and time of the yarn were 75℃ and 48h, respectively;

[0056] (3) Molded through impregnation and vulcanization processes;

[0057] (4) The extraction force and peel force were tested separately. The specific test results are shown in the table below:

[0058] Table 4. Effect of component C content in activator F formulation on the adhesion between yarn and rubber.

[0059]

[0060] As shown in Table 4, when the content of component C in the activator F formulation is 10%, it has better extraction force and peel force values.

[0061] Example 6

[0062] This invention discloses a method for improving the adhesion properties of yarn to rubber using an activator formulation, comprising the following steps:

[0063] (1) The activator formulation F was used in the spinning process, with the contents of components A, B, C and D being 56%, 30.2%, 10% and 3.8% respectively, and the oiling rates being set to 0.25%, 0.27%, 0.29%, 0.31%, 0.33% and 0.35% respectively;

[0064] (2) The aging temperature and time of the yarn were 75℃ and 48h, respectively;

[0065] (3) Molded through impregnation and vulcanization processes;

[0066] (4) The extraction force and peel force were tested separately. The specific test results are shown in the table below:

[0067] Table 5. Effect of oiling rate on the adhesion between yarn and rubber.

[0068]

[0069] As shown in Table 5, when the yarn oiling rate is 0.31%, activator formulation F has better pull-out force and peel force values.

[0070] Example 7

[0071] This invention discloses a method for improving the adhesion properties of yarn to rubber using an activator formulation, comprising the following steps:

[0072] (1) The activator formulation F was used in the spinning process, with the contents of components A, B, C and D being 56%, 30.2%, 10% and 3.8% respectively, and the oiling rate was set at 0.31%.

[0073] (2) The aging temperatures of the yarns were 60℃, 65℃, 70℃, 75℃ and 80℃, and the time was 48h.

[0074] (3) Molded through impregnation and vulcanization processes;

[0075] (4) The extraction force and peel force were tested separately. The specific test results are shown in the table below:

[0076] Table 6. Effect of aging temperature on the adhesion between yarn and rubber.

[0077] Yarn aging temperature 60℃ 65℃ 70℃ 75℃ 80℃ Extraction force (N) 155.53 167.81 171.89 182.68 171.11 Peel force (N) 79.30 85.01 93.55 115.82 105.51

[0078] As shown in Table 6, when the aging temperature of the yarn is 75℃, the activator formulation F has better pull-out force and peel force values.

[0079] Example 8

[0080] This invention discloses a method for improving the adhesion properties of yarn to rubber using an activator formulation, comprising the following steps:

[0081] (1) The activator formulation F was used in the spinning process, with the contents of components A, B, C and D being 56%, 30.2%, 10% and 3.8% respectively, and the oiling rate was set at 0.31%.

[0082] (2) The aging temperature of the yarn is 75℃, and the aging times are 24h, 36h, 48h, 60h and 72h respectively;

[0083] (3) Molded through impregnation and vulcanization processes;

[0084] (4) The extraction force and peel force were tested separately. The specific test results are shown in the table below:

[0085] Table 7. Effect of aging time on the adhesion between yarn and rubber.

[0086] Yarn aging time 24h 36h 48h 60h 72h Extraction force (N) 160.32 173.74 182.68 181.52 180.10 Peel force (N) 99.59 106.55 115.82 115.30 114.51

[0087] As shown in Table 7, when the yarn aging time is 48 hours, activator formulation F has better pull-out force and peel force values.

[0088] Example 9

[0089] (1) The activator formulation F was used in the spinning process, with the contents of components A, B, C and D being 56%, 30.2%, 10% and 3.8% respectively, and the oiling rate was set at 0.31%. The yarn linear density was 2240 dtex.

[0090] (2) The aging temperature of the yarn is 75℃ and the time is 48h;

[0091] (3) Molded through impregnation and vulcanization processes;

[0092] (4) Test the extraction force and peeling force respectively.

[0093] Table 8. Effect of yarn linear density on rubber adhesion.

[0094] Yarn linear density (dtex) 1120 2240 Extraction force (N) 182.68 191.87 Peel force (N) 115.82 157.16

[0095] When the yarn has a higher fineness, the pull-out force and peel force are also higher.

[0096] Comparative Example 1

[0097] Compared to the activator formulation in Example 2, component A was replaced with epoxy resin (glycerol glycidyl ether). All other processes were the same as in Example 2. Pull-out force and peel force were tested, and the results were 172.24 N and 107.2 N, respectively.

[0098] As shown in Comparative Example 1, using epoxy resin as an activator results in lower yarn-rubber adhesion compared to using alkyl silane. In existing technologies, epoxy resin is used as the activator, requiring a ring-opening reaction to expose active sites before polymerization with the impregnation solution, followed by vulcanization with the rubber. Alkyl silane does not require ring-opening and polymerizes more fully with the impregnation solution under the same conditions, increasing the yarn-rubber adhesion.

[0099] Comparative Example 2

[0100] Compared to the activator formulation F in Example 2, component B is omitted, and the mass ratio of components A, C, and D is 56:10:3.8. These three components are mixed at room temperature to form the activator. All other processes are the same as in Example 2. Pull-out force and peel force were tested, and the results were 134.16 N and 79.23 N, respectively.

[0101] Comparative Example 3

[0102] Compared to the activator formulation F in Example 2, components C and D are omitted. The mass ratio of components A and B is 56:30.2, and they are mixed at room temperature to form the activator. Pull-out force and peel force were tested, and the results were 72.39 N and 56.18 N, respectively.

[0103] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, are covered within the scope of protection of the present invention.

Claims

1. An activator for improving the adhesion between yarn and rubber, characterized in that, The activator is composed of 38-68 wt% component A: alkylsilane, 24.2-41.2 wt% component B: fatty acid polyoxyethylene ester, 5.5-13 wt% component C: triethylene glycol dimethyl ether, and 0.6-4.7 wt% component D: alkylphenol polyoxyethylene ether; the alkylsilane is γ-(2,3-epoxypropoxy)propyltrimethoxysilane; and the yarn is high-modulus, low-shrinkage polyester industrial yarn.

2. The activator for improving the adhesion between yarn and rubber as described in claim 1, characterized in that, Component A: 56 wt% alkylsilane, Component B: 30.2 wt% fatty acid polyoxyethylene ester, Component C: 10 wt% triethylene glycol dimethyl ether, Component D: 3.8 wt% alkylphenol polyoxyethylene ether.

3. A method for preparing the activator according to claim 1 or 2, characterized in that, The activator is obtained by thoroughly mixing components A, B, C, and D at room temperature.

4. A method for improving the adhesion between yarn and rubber using the activator as described in claim 1 or 2, characterized in that, This includes the processes of yarn oiling activation, yarn aging, impregnation, and vulcanization; the yarn is high-modulus, low-shrinkage polyester industrial yarn with a fineness of 800D-1500D.

5. The method for improving the adhesion between yarn and rubber according to claim 4, characterized in that, The oiling rate for spinning is 0.25~0.35%, where oiling refers to the addition of an activator.

6. The method for improving the adhesion between yarn and rubber according to claim 4, characterized in that, During aging, heat treatment is used, with an aging temperature of 60~80℃ and an aging time of 24~72 hours.

7. The method for improving the adhesion between yarn and rubber according to claim 4, characterized in that, The impregnation is a single impregnation process.

8. Use of the activator according to claim 1 or 2 in improving the adhesion between yarn and rubber.

9. Use of the preparation method according to claim 3 in improving the adhesion between yarn and rubber.

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