TW201934625A - Polyolefin elastomer composition and foamed elastomer including a copolymer, an unsaturated aliphatic polyolefin, an organic peroxide and a metal acrylate - Google Patents

Abstract

A polyolefin elastomer composition includes a copolymer, an unsaturated aliphatic polyolefin, an organic peroxide and a metal acrylate, wherein the copolymer is an ethylene copolymer, a polyolefin block copolymer or a combination thereof; the ratio of the unsaturated aliphatic polyolefin to the copolymer is from 1:3 to 3:1; and given that the total amount of the copolymer and the unsaturated aliphatic polyolefin is 100 parts by weight, the amount of organic peroxide is from 0.1 part by weight to 1 part by weight, and the amount of the metal acrylate that is from 0.1 part by weight to 5 parts by weight. With the polyolefin elastomer composition, a foamed elastomer having high impact resilience and low compression permanent deformation can be obtained, and a step of preparing a foamed elastomer required for secondary press processing due to insufficient structural strength can be omitted.

Description

Polyolefin elastomer composition and foamed elastomer

The invention relates to a foamed crosslinked polyolefin elastomer composition and a foamed elastomer, which are characterized in that the foamed elastomer molded product has a comfortable touch and can maintain low compression deformation and high compression ratio at a high expansion ratio. Advantages of high backlash flexibility.

Lightweight is the goal pursued by many products. Even lightweight materials have attracted much attention. Among them, lightweight materials made by foaming technology have the advantages of low specific gravity and good flexibility, and are widely used in building interior and exterior decoration. Materials, materials for people's livelihood, materials for car interior decoration, door and window glass frames, packaging materials and shoe materials.

However, although foamed elastomers made by foaming technology have the advantage of being lightweight, foaming also causes their structural properties to be reduced. People in this art have worked hard to add appropriate crosslinkers to the foaming composition. In order to strengthen the degree of cross-linking between resins, and then improve the melt strength of the resin, in order to maintain the lightweight of the foamed elastomer and reduce the loss of structural properties.

In the current foaming technology, the technology for making foamed elastomers using ethylene / vinyl acetate copolymers as raw materials is relatively mature. Its advantages are light weight, softness, cheapness, and some toughness; but the disadvantage is that It is difficult for foamed elastomers to take into account various properties, for example, it is easy to lose resilience due to long-term compression and poor permanent compression.

Taking Japanese Patent Publication No. 11-206406 as an example, it discloses ethylene-vinyl acetate copolymer (EVA), ethylene / butylene copolymer (EBM), organic The foamed composition composed of acid peroxide, sulfur, and foaming agent, and the crosslinked foamed elastomer made of the composition, although it can slightly improve the problems of specific gravity, material resilience and permanent compression deformation, but its performance is still insufficient. .

In addition, according to the contents of U.S. Invention Patent Bulletin No. 7179764 and Republic of China Invention Patent Bulletin No. 247777 as examples, it is disclosed that the ratio of ethylene / alpha-olefin copolymer or its mixture is adjusted to organic acid peroxidation. Composition, cross-linking auxiliary (preferably triallyl isocyanurate (TAIC) or triallyl cyanurate (TAC)) and a foaming composition of a foaming agent , Can improve the expansion ratio of foamed elastomer, compression set and tear strength, but still not the best performance.

According to the contents of U.S. Invention Patent Bulletin No. 6720364 and Republic of China Invention Patent Bulletin No. 574296, they are disclosed in ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer, and high-pressure low-density polyethylene. Adding organic peroxide, cross-linking assistant, organometallic salt compound (preferably zinc diacrylate or zinc dimethacrylate) and foaming agent to the foaming composition, and then subjecting it to secondary pressing to avoid surface breakage Foam to balance the properties of foamed elastomers in terms of weight, compression set, tear strength and impact resistance.

In addition, according to the contents of U.S. Invention Patent Bulletin No. 9493623 and Republic of China Invention Patent Bulletin No. 415882, it discloses a polymer consisting of an ethylene copolymer, an ethylene aromatic monomer unit, and a conjugated diene monomer unit having an unsaturated bond. Composition of polyolefin elastomer composition, which can improve the weight, softness, compression set and tear strength of the foamed elastomer. It is also revealed that the aforementioned polyolefin elastomer composition is made into foamed elasticity. In order to maintain the foamed elastomer with a certain structural strength, it is necessary to undergo secondary pressing to improve the structural strength of the foamed elastomer to achieve good resilience and molding stability. It can be used in shoe midsoles. . However, the steps mentioned above that require secondary press processing will not only reduce the flexibility, but also increase the processing time, complexity and production cost of the process.

In view of the above problems, an object of the present invention is to provide a polyolefin elastomer composition and a foamed elastomer. The foamed elastomer has good backlash elasticity and compression set, and has a certain structural strength.

To achieve the above object, the polyolefin elastomer composition of the present invention includes: a copolymer, the copolymer being an ethylene copolymer, a polyolefin block copolymer or a combination thereof; Unsaturated aliphatic polyolefin, the weight ratio of the amount of the unsaturated aliphatic polyolefin to the copolymer is 1: 3 to 3: 1; an organic peroxide, the copolymer and the unsaturated aliphatic polyolefin The total amount of the organic peroxide is 100 parts by weight, the amount of the organic peroxide is 0.1 to 1 part by weight; and an acrylic metal salt, based on the total amount of the copolymer and the unsaturated aliphatic polyolefin, 100 parts by weight, The acrylic metal salt is used in an amount of 0.1 to 5 parts by weight. By the above-mentioned technical means, the polyolefin elastomer composition of the present invention can make the foamed elastomer having sufficient structural strength, so it can overcome the need for the secondary foaming process of the foamed elastomer in the past due to insufficient structural strength. After the processing step is omitted, the processing time and complexity of the manufacturing process can be reduced, and the production cost can be reduced.

Preferably, the ethylene copolymer is selected from the group consisting of ethylene / vinyl acetate copolymer, ethylene / octane copolymer, polymer Ethylene (PE), ethylene / α-olefin copolymer, ethylene / α-olefin non-conjugated diene copolymer, ethylene / α-olefin copolymer Ethylene / acrylic copolymer, ethylene / methyl acrylic copolymer, ethylene / methyl acrylate copolymer, ethylene / methyl methacrylate copolymer ( ethylene / methyl methacrylate copolymer), ethylene / ethyl acrylate copolymer, ethylene / ethyl methacrylate copolymer, ethylene / butyl acrylate copolymer acrylate copolymer), ethylene / butyl methacrylate copolymer, and mixtures thereof.

More preferably, the copolymer is selected from the group consisting of ethylene / vinyl acetate copolymer, ethylene / octene copolymer, polyolefin block copolymer, and mixtures thereof.

More preferably, the copolymer may include a combination of at least two kinds of polymers, that is, the polymer may include a combination of at least two kinds of ethylene copolymers, or a combination of at least two kinds of polyolefin block copolymers. The combination, or may be a combination comprising at least one ethylene copolymer and at least one polyolefin block copolymer. For example, the copolymer may be a combination of ethylene / vinyl acetate copolymer and ethylene / octene copolymer, a combination of ethylene / vinyl acetate copolymer and polyolefin block copolymer, or an ethylene / octene copolymer And polyolefin block copolymers.

Even more preferably, when the copolymer is a mixture of two ethylene copolymers, the foamed elastomer made from the polyolefin elastomer composition may have better resilience or smaller compression set, and may Adjust the specific gravity, hardness and other characteristics according to the type and ratio of mixing. When the copolymer is a mixture of an ethylene copolymer and a polyolefin block copolymer, the foamed elastomer prepared with the polyolefin elastomer composition can finely adjust the specific gravity and hardness, and has excellent backlash elasticity and compression set.

Preferably, the unsaturated aliphatic polyolefin is selected from the group consisting of ethylene propylene diene monomer rubber (EPDM), polybutadiene rubber (BR), Butyl rubber (IIR), natural rubber (NR), isoprene rubber (IR), and mixtures thereof.

More preferably, the unsaturated aliphatic polyolefin is selected from the group consisting of ethylene-propylene-diene rubber, butadiene rubber, and mixtures thereof.

Preferably, the organic peroxide is selected from the group consisting of the following: dicumyl peroxide (dicumyl peroxide), bis (tert-butylperoxy isopropyl) benzene (bis (tert -butylperoxyisopropyl ) benzene), t-butyl perbenzoate peroxide (tert -butyl peroxybenzoate), peroxide (meth benzoyl) (di (methylbenzoyl) peroxide) and mixtures thereof.

Preferably, when the organic peroxide is used in an amount of 0.1 parts by weight to 1 part by weight, it can help optimize the specific gravity of the foamed elastomer produced, control the hardness specifications, and improve the compression permanent deformation of the foamed elastomer. proportion. More preferably, the organic peroxide is used in an amount of 0.2 to 0.5 parts by weight.

Preferably, the polyolefin elastomer composition includes a foaming agent, and the foaming agent may be an azo compound, a nitroso compound, or a sulfohydrazine compound, wherein the azo compound may be an azomethine Amines, ammonium azodicarboxylate, azobisisobutyronitrile, diisopropyl azodicarboxylate, diethyl azodicarboxylate, diazoaminobenzene or barium azodicarboxylate; nitroso compounds It can be N, N′-dinitrosopentamethylenetetramine or N, N′-dimethyl-N, N′-dinitroso-p-xylylenediamine; sulfohydrazine compounds can be 4,4′-disulfonylhydrazine diphenyl ether, p-benzenesulfonylhydrazine, 3,3′-disulfonylhydrazine diphenylsulfonium, 4,4′-diphenylsulfinylhydrazine, 1,3-benzenediphenyl Sulfarazine, 1,4-benzenedisulfazine.

Preferably, the amount of the acrylic metal salt is 0.1 to 5 parts by weight. More preferably, the amount of the acrylic metal salt is from 1 part by weight to 2.5 parts by weight.

Preferably, the acrylic metal salt is a zinc acrylate compound, and the zinc acrylate compound includes a substituted or unsubstituted zinc acrylate compound. Specifically, the unsubstituted zinc acrylate salt compound may be a zinc acrylate salt, and the substituted zinc acrylate salt compound may be a zinc 2-methacrylate salt, a zinc 2-ethylacrylate salt, or 2-propane Zinc acrylate, zinc 2-butyl acrylate, zinc 2-pentyl acrylate, zinc 2-hexyl acrylate, or mixtures thereof, but not limited thereto.

Preferably, the acrylic metal salt may further include a dispersant, and the dispersant is a polytetrafluoroethylene wax or a polytetrafluoroethylene-modified polyethylene wax; more preferably, based on the total weight of the acrylic metal salt The added amount of the dispersant is 0.1% by weight to 5% by weight. When the acrylic metal salt is added with a dispersant, the foamed elastomer can be uniformly cross-linked and the compression set can be improved.

Preferably, the polyolefin elastomer composition may include an additive to help thermal stability and cross-linking uniformity of the material. The additive includes a fatty acid having a carbon number of 12 to 20, a fatty acid metal salt (for example, zinc stearate). , Calcium stearate, barium stearate, etc.), polyethylene wax (PE Wax), zinc oxide, urea, talc, calcium carbonate, titanium dioxide, kaolin, or a combination thereof. More preferably, the additives may be stearic acid, zinc stearate, and zinc oxide.

To achieve the foregoing object, the present invention further provides a foamed elastomer, which is prepared from the aforementioned polyolefin elastomer composition.

With the above technical means, the foamed elastomer can take into account both the appropriate structural strength and the characteristics of high resilience elasticity and low compression and permanent deformation, and has a wider range of applications, such as sporting goods, transportation, construction materials or consumer goods, And it can be used directly as the material of grip, seat cushion, yoga mat, insole or shoe midsole.

Specifically, the foamed elastomer can be molded by the aforementioned polyolefin elastomer composition through processing methods such as compression foaming, in-mold foaming, or injection foaming.

Preferably, the foamed elastomer has a specific gravity of 0.1 g / cm ³ to 0.25 g / cm ³ .

More preferably, when the specific gravity of the foamed elastomer is greater than or equal to 0.15 g / cm ³ and less than 0.20 g / cm ³ , the foamed elastomer may have a Shore hardness of 37C to 40C, 68% to 76% Backlash elasticity, 25% to 32% compression set and tear strength of 8 kg / cm to 12 kg / cm; when the specific gravity of the foamed elastomer is greater than or equal to 0.20 g / cm ³ and less than or equal to 0.25 g / cm ³ , the foamed elastomer can have a Shore hardness of 38C to 40C, a backset elasticity of 68% to 71%, a compression set of 29% to 34%, and a tear of 9 kg / cm to 13 kg / cm Cracking strength.

Preferably, the Shore E hardness of the foamed elastomer is 35C to 45C.

Preferably, the rebound elasticity of the foamed elastomer is 60% to 80%. More preferably, the foamed elastomer has a backwash elasticity of 65% to 80%.

Preferably, the compression set of the foamed elastomer is 20% to 40%. More preferably, the foamed elastomer has a compression set of 20% to 35%.

Preferably, the foamed elastomer has a specific gravity lower than 0.2 g / cm ³ and a tear strength of 5 kg / cm to 15 kg / cm. More preferably, the foamed elastomer has a specific gravity of less than 0.2 g / cm ³ and a tear strength of 8 kg / cm to 15 kg / cm.

The polyolefin elastomer composition and foamed elastomer of several examples are listed below, and the specific tests of specific gravity, hardness, resilience, compression set, and tear strength are performed in the following manner. 1. Specific gravity: According to the D792 standard set by the American Society for Testing and Materials (ASTM), the foamed elastomer is cut into test pieces with a size of 3 × 2.5 × 1 cm and placed at a temperature of 23 ± 2 ° C and 50 ± 10% humidity for at least 40 hours, and then weighed with an electronic balance (brand: Percisa, model: 125A SCS) at 23 ± 2 ° C, taking three groups Data are averaged and specific gravity calculated. 2. Hardness: According to the D2240 standard stipulated by ASTM, the foamed elastomer is cut into round or square test pieces with a thickness of at least 6 mm, and the center of the test piece is at least 12 mm from each side, and then used. The hardness tester (brand: TECLOCK, model: GS-701N TYPE C) is measured at a temperature of 23 ± 2 ° C, the load is 5 kg, the read value is 5 seconds, and the average of the five sets of data is used as the measurement The resulting hardness. 3. Reverse elasticity: According to the D2632 standard stipulated by ASTM, the foamed elastomer is cut into a test piece with a thickness of 12.5 ± 0.5 mm, and the center of the test piece is at least 14 mm from each side, and then, at 23 ± Using a vertical elasticity testing machine (brand: High-speed Rail Technology, model: GT-7042-V1) at 2 ° C, a 28-gram impact hammer was dropped on the foamed elastomer from a height of 40 cm, and then a ruler was used. The rebound height of the foamed elastomer was read visually, and a total of three groups of test pieces were measured. Each test piece was measured 6 times, and the 4th to 6th rebound heights were averaged. 4. Compression permanent deformation: According to the D395 standard set by ASTM, the foamed elastomer is cut into a circular test piece with a diameter of 29.0 ± 0.5 mm. Before measurement, the permanent compression distortion tester (brand: HSR Technology, Model: GT-7049) Preheat in an oven at 50 ° C for at least 2 hours, and place the test piece in an environment with a temperature of 23 ± 2 ° C and a humidity of 50 ± 10% for at least 3 hours. The compression distortion tester compresses the test piece to 50% of its original thickness, and compresses it continuously at 50 ° C for 6 hours. After the pressure is released for 30 minutes, the thickness of the test piece is measured. At least two sets of test pieces are measured, and the average value is calculated. After calculating the compression set, the compression set is calculated as follows: C _B = [(t _o -t _i ) / (t _o -t _n )] × 100%; C _B = percentage of compression set (Method B) T _o = original thickness of the specimen; t _i = final thickness of the specimen; t _n = thickness of the space bars used. 5. Tear strength: According to the D624 standard stipulated by ASTM, the foamed elastomer is cut into a test piece with a thickness of 1 cm using a mold C-type cutter, and a tensile tester is used at a temperature of 23 ± 2 ° C. (Brand: High-speed rail technology, model: AI-7000S) and test the test piece at a tensile speed of 500 ± 50 mm per minute, the number of measurements is 3 groups, and the average value of the 3 groups of data is taken as the tear strength.

Examples 1 to 10 : Preparation of polyolefin elastomer composition

Complete copolymer (A), unsaturated aliphatic polyolefin (B), organic peroxide (C), acrylic metal salt (D), foaming agent (E) and additives, the additives are stearic acid, stearic acid Zinc acid and zinc oxide.

In the following examples, the copolymer (A) can be selected from: ethylene / vinyl acetate copolymer (A1) (EVATHENE UE-634 produced by Taiwan Polymerization Corporation), ethylene / octene copolymer (A2) (purchased from From DOW, trade name: Engage 8200), ethylene / octene copolymer (A3) (purchased from DOW, trade name: Engage 8150), polyolefin block copolymer (A4) (purchased from DOW, trade name: Infuse 9530) ) Or a mixture thereof. The unsaturated aliphatic polyolefin (B) can be selected from: EPDM (B1) (purchased from DOW, trade name: Nordel IP 4570), EPDM (B2) (purchased from Sabic, trade name) : PDM 756), butadiene rubber (B3) (purchased from Lanxess, trade name: Buna CB23) or a mixture thereof. The organic peroxide (C) can be selected from: dicumyl peroxide (C1) (purchased from Juntai Chemical Company, trade name: ACEOX DCP), bis (2-tert-butylperoxyisopropyl) benzene (C2) (purchased from Juntai Chemical Company, trade name: ACEOX BIBP) or a mixture thereof. The acrylic metal salt (D) can be selected from: zinc hard acrylic acid salt composition (D1) (containing 92 wt% zinc acrylic acid / 8 wt% zinc stearate; using K-CURE 339 produced by San Akira Co., Ltd.), zinc acrylate Salt composition (D2) (contains 91.5wt% zinc acrylate / 7.5wt% zinc stearate / 1wt% polytetrafluoroethylene modified polyethylene wax; K-CURE 339F produced by San Akira Co., Ltd.) or its mixture. The foaming agent (E) was selected from azomethoxamine (purchased from Juntai Chemical Company, trade name: ACEOX AC3000).

First, the copolymer (A), unsaturated aliphatic polyolefin (B), acrylic metal salt (D) and additives were added to a kneader (brand: Lina Machinery, model: KD-3-20), starting at 80 ° C to 125 ° C, melt-knead at 40 rpm for 5 minutes, then add organic peroxide (C) and blowing agent (E), and at a temperature of 80 ° C to 125 ° C, 40 rpm Melt and knead for 5 minutes at a rotating speed to form a polyolefin elastomer composition.

The component amounts of the copolymer (A), the unsaturated aliphatic polyolefin (B), the organic peroxide (C), and the acrylic metal salt (D) in the polyolefin elastomer composition of each example are listed in Table 1; In each embodiment, the amount of the blowing agent (E) in the polyolefin elastomer composition is fixed at 3.35 parts by weight, stearic acid is fixed at 0.44 parts by weight, zinc stearate is fixed at 0.67 parts by weight, and zinc oxide is fixed. It is 1.11 parts by weight to investigate the influence of the amount of components of the copolymer (A), unsaturated aliphatic polyolefin (B), organic peroxide (C), and acrylic metal salt (D) on the properties of the foamed elastomer. .

Comparative example 1 to 4 : Preparation of polyolefin elastomer composition

Comparative Examples 1 to 4 prepared the polyolefin elastomer composition roughly by the method of Examples 1 to 10. The difference was that the polyolefin elastomer composition of Comparative Examples 1 to 4 contained only the copolymer (A) and organic peroxide. (C), acrylic metal salt (D), foaming agent (E) and additives, without adding unsaturated aliphatic polyolefin (B).

The component amounts of the copolymer (A), organic peroxide (C), and acrylic metal salt (D) in the polyolefin elastomer composition of each comparative example are shown in Table 1. The amount of the foaming agent (E) and the amounts of additives such as stearic acid, zinc stearate, and zinc oxide were the same as those of Examples 1 to 10. Table 1: Parts by weight of each component in the polyolefin elastomer composition of Examples 1 to 10 and Comparative Examples 1 to 4.

Examples 11 to 20 And comparative example 5 to 8 : Preparation of foamed elastomer

The polyolefin elastomer compositions of Examples 1 to 10 and Comparative Examples 1 to 4 were cut into pellets having a length of about 3 mm through a pelletizer (brand: Lina Machinery, model: KD-FR-50) or It is rolled into a film by a double-roller mixer (brand: Xufeng, model: HF-2RM).

Next, the prepared pellets or films are placed in a metal mold and heated at a temperature of 160 ° C to 170 ° C and a pressure of 150 kg / cm ² to 170 kg / cm ² for 10 to 20 minutes, which can be sequentially The foamed elastomers of Examples 11 to 20 and Comparative Examples 5 to 8 were prepared, and the foamed elastomers were subjected to the aforementioned methods to test the specific gravity, hardness, resilience, compression set and tear strength results. In Table 2. Table 2: Characteristics of the foamed elastomers of Examples 11 to 20 and Comparative Examples 5 to 8.

According to the results in Tables 1 and 2, after the unsaturated aliphatic polyolefin is added and the amount of each component is controlled, the foamed elastomers of Examples 11 to 20 of the present invention may have a Shore hardness of 37C to 40C, 68% To 76% backlash elasticity, 25% to 34% compression set and tear strength of 8 kg / cm to 13 kg / cm, compared to the foamed elastomers of Comparative Examples 5 to 8 having higher backlash elasticity 、 Lower compression set and higher tear strength. According to this, the foamed elastomer produced by the present invention has proper structural strength, low compression set and excellent resilience properties, which can expand its applicability. .

In addition, since the foamed elastomer made of the polyolefin elastomer composition of the present invention has an appropriate specific gravity and hardness, it can be superior to the reverse elasticity and compression permanent deformation of the prior art without the need for secondary press processing, which can save processing. Time and complexity, to achieve the effect of reducing production costs.

According to the results of Examples 11 and 17, when the specific gravity of the foamed elastomer is greater than or equal to 0.20 and less than or equal to 0.25, the foamed elastomer may have a Shore hardness of 38C to 40C, and a backwash of 68% to 71%. Elasticity, compression set from 29% to 34%, and tear strength from 9 kg / cm to 13 kg / cm.

According to the results of Examples 12 to 16 and 18 to 20, when the specific gravity of the foamed elastomer is greater than or equal to 0.15 and less than 0.20, the foamed elastomer may have a Shore hardness of 37C to 40C, 68% to 76% Backlash elasticity, compression set of 25% to 32% and tear strength of 8 kg / cm to 12 kg / cm.

According to this, users can choose foaming elastomers with appropriate specific gravity and hardness according to their needs, and the foaming elastomers can achieve backlash elasticity greater than or equal to 68%, permanent compression less than or equal to 34%, and greater than or equal to Tear strength equal to 8 kg / cm.

Further comparison, from the results of Examples 1, 2, 11, and 12, it can be known that when the amount of the organic peroxide (C) in the polyolefin elastomer composition is large, a better compression set can be obtained.

It can be known from the results of Examples 2, 3, 12 and 13 or Examples 9, 10, 19 and 20 that the properties of the foamed elastomer are also affected when different acrylic metal salts are used; Example 3 is an example. The acrylic acid metal salt (D) added in Examples 2 and 3 is a zinc acrylic acid salt. The difference is that the zinc acrylic acid salt used in Example 3 is additionally added with polytetrafluoroethylene wax or polytetrafluoroethylene wax. The dispersant of fluoroethylene-modified polyethylene wax improves the dispersibility and reactivity of zinc acrylate. From the results in Table 2, it can be seen that the hardness and compression set of the foamed elastomer of Example 13 were obtained. Improve; similarly, in Example 9 and Example 10, the acrylic acid metal salt (D) added in Examples 9 and 10 are all zinc acrylate, the difference is that the zinc acrylate used in Example 10 is additionally added A polytetrafluoroethylene wax or a polytetrafluoroethylene-modified polyethylene wax was used as a dispersant. From the results in Table 2, it can be seen that the hardness and compression set of the foamed elastomer of Example 20 were also improved.

When at least two copolymers (A) are used in combination, the rebound elasticity of the foamed elastomer can be improved and the compression set can be reduced. Based on the results of Examples 2, 4, 12, and 14, the polyolefin elasticity of Example 4 can be obtained The two ethylene polymers (that is, ethylene / vinyl acetate copolymer (A1) and ethylene / octene copolymer (A2)) are mixed in the body composition, which can make the foamed elastomer of Example 14 have better backlash elasticity. And lower compression set; similarly, it can be known from the results of Examples 2, 5, 12 and 15 that Example 5 used two ethylene copolymers (ie, ethylene / vinyl acetate copolymer (A1 ) And ethylene / octene copolymer (A3)), the foamed elastomer of Example 15 can have better backwash elasticity and lower compression set.

A further comparison is made between the case where two ethylene polymers are used as the copolymer (A) and the case where the ethylene copolymer and the polyolefin block copolymer are used as the copolymer (A), and Examples 4, 5, 8, 14, and 15 are also compared. It can be known from the results of 18 that when the copolymer is a mixture of two copolymers, the foamed elastomer prepared from the polyolefin elastomer composition has better resilience and smaller compression set; When the copolymer is a mixture of an ethylene copolymer and a polyolefin block copolymer, the polyolefin elastomer composition can be made to have fine-adjustable specific gravity and hardness (Shore hardness 37C to 40C) and still have better backwash elasticity and compression. Permanently deformed foamed elastomer.

To sum up, the polyolefin elastomer composition of the present invention can be used to obtain a foamed elastomer that has both appropriate structural strength, high resilience elasticity and low compression set characteristics, and can omit secondary compression in the past when manufacturing foamed elastomers Processing steps.

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Claims (13)

A polyolefin elastomer composition includes: a copolymer, the copolymer being an ethylene copolymer, a polyolefin block copolymer, or a combination thereof; an unsaturated aliphatic polyolefin, the unsaturated aliphatic polyolefin The amount of the organic peroxide used is 1: 3 to 3: 1; an organic peroxide, with a total amount of the copolymer and the unsaturated aliphatic polyolefin of 100 parts by weight, the amount of the organic peroxide used is: 0.1 parts by weight to 1 part by weight; and an acrylic metal salt, with a total amount of the copolymer and the unsaturated aliphatic polyolefin of 100 parts by weight, and the amount of the acrylic metal salt used is 0.1 to 5 parts by weight. The polyolefin elastomer composition according to claim 1, wherein the ethylene copolymer is selected from the group consisting of ethylene / vinyl acetate copolymer, ethylene / octene copolymer, polyethylene, Ethylene / α-olefin copolymer, ethylene / α-olefin non-conjugated diene copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / methyl acrylate copolymer, ethylene / methyl methacrylate Copolymers, ethylene / ethyl acrylate copolymers, ethylene / ethyl methacrylate copolymers, ethylene / butyl acrylate copolymers, ethylene / butyl methacrylate copolymers, and mixtures thereof. The polyolefin elastomer composition according to claim 2, wherein the copolymer is selected from the group consisting of an ethylene / vinyl acetate copolymer, an ethylene / octene copolymer, and a polyolefin block Copolymers and mixtures thereof. The polyolefin elastomer composition according to claim 1, wherein the unsaturated aliphatic polyolefin is selected from the group consisting of ethylene-propylene-diene rubber, butadiene rubber, butyl rubber, Natural rubber, isoprene rubber and mixtures thereof. The polyolefin elastomer composition according to claim 4, wherein the unsaturated aliphatic polyolefin is selected from the group consisting of ethylene-propylene-diene rubber, butadiene rubber, and mixtures thereof. The polyolefin elastomer composition according to claim 1, wherein the organic peroxide is selected from the group consisting of dicumyl peroxide, di (tert-butylperoxyisopropyl) Benzene, tert-butyl peroxybenzoate, bis (methylbenzidine) peroxide and mixtures thereof. The polyolefin elastomer composition according to claim 1, wherein the acrylic metal salt composition is a zinc acrylate compound. The polyolefin elastomer composition according to claim 7, wherein the zinc acrylate salt compound is zinc acrylate, zinc 2-methacrylate, zinc 2-ethylacrylate, zinc 2-propylacrylate, Zinc 2-butyl acrylate, Zinc 2-pentyl acrylate, Zinc 2-hexyl acrylate, or mixtures thereof. The polyolefin elastomer composition according to any one of claims 1 to 8, wherein the acrylic metal salt includes a dispersant, and based on the total weight of the acrylic metal salt, the added amount of the dispersant is 0.1 weight Percent to 5 weight percent. The polyolefin elastomer composition according to claim 9, wherein the dispersant is a polytetrafluoroethylene wax or a polytetrafluoroethylene-modified polyethylene wax. A foamed elastomer prepared from the polyolefin elastomer composition according to any one of claims 1 to 10. The foamed elastomer according to claim 11, wherein the foamed elastomer has a backlash elasticity of 60% to 80%. The foamed elastomer according to claim 11 or 12, wherein the compression set of the foamed elastomer is 20% to 40%.