Hot-melt adhesive composition comprising bio-base material

Abstract

The present invention relates to a hot-melt adhesive composition comprising a biodegradable plastic, a thermoplastic polymer, a tackifier and a plasticizer, wherein the biodegradable plastic includes polyhydroxyalkanoate (PHA). The hot-melt adhesive composition according to the present invention has lower viscosity and higher adhesiveness compared to a petroleum-based hot-melt composition, and can be used as an eco-friendly hot-melt adhesive composition having physical properties corresponding to an excellent recycling criteria grade under recyclability assessment criteria.

Description

Hot melt adhesive composition comprising a bio-based material

[0001] The present invention relates to a hot melt adhesive composition comprising a bio-based material.

[0002] Polymer adhesives can be categorized into chemically reactive, solvent-based, and hot melt types, depending on the curing process. Among these, hot melt polymer adhesives are easy to use and can meet emerging environmental requirements.

[0003] Hot melt adhesives are 100% solid thermoplastic resins that do not contain solvents or water, either alone or mixed with other substances. They are applied and adhered to the surface of the adherend while in a heated, molten state, and then solidify and exhibit adhesive strength when cooled.

[0004] Conventional commercial hot melt adhesives are generally classified into ethylene-vinylacetate, polyolefin, styrene block copolymer, polyamide, polyester, and urethane (reactive hot melt) types depending on the base resin used. Since the base resin is mainly composed of petroleum-based materials, they have the disadvantage of being less environmentally friendly, such as generating a large amount of volatile organic compounds (VOCs) during the manufacturing or use process.

[0005] Therefore, considering environmental friendliness, it is necessary to replace all or part of the base resin, which is the main component of hot melt adhesives, with biomaterials that have a CO2 reduction effect.

[0006] Korean Patent Publication No. 10-2016-0002546 discloses a hot melt adhesive using starch, an eco-friendly material, and in order to improve the poor storage stability of existing starch-based hot melt adhesives, a starch-thermoplastic polymer copolymer is manufactured, followed by a plasticizer, wax, and a tackifier. In addition, Korean Patent Publication No. 10-2318930 discloses a method for manufacturing polyhydroxyalkanoate (PHA) with various monomer compositions and shows that PHA polymers including 2HB (2-hydroxybutyate; 2HB) can be usefully applied as hot melt adhesives by utilizing the large temperature-dependent viscosity change characteristic of PHA polymers. However, there are no examples or specific examples regarding the development or composition of hot melt adhesives using PHA, making it difficult to determine the applicability of hot melt adhesives.

[0007] Although there are many movements to replace petroleum-based materials in hot melt adhesives with bio-based materials, there is still no development of hot melt adhesive technology using PHA, one of the bio-based materials.

[0008] [Prior Art Literature]

[0009] (Patent Document 1) KR 10-2016-0002546 A1

[0010] (Patent Document 2) KR 10-2318930 B1

[0011] The present invention provides an eco-friendly hot melt adhesive composition that replaces petroleum-based materials in hot melt adhesives with bio-based materials.

[0012] The present invention provides a hot melt adhesive composition comprising a biodegradable plastic, a thermoplastic polymer, a tackifier and a plasticizer, wherein the biodegradable plastic comprises polyhydroxyalkanoate (PHA).

[0013] The present invention provides a hot melt adhesive composition having properties similar to petroleum-based hot melt products containing 40 to 90 wt% of a bio-based material by applying not only PHA, an eco-friendly bio-based material, but also various bio-based materials.

[0014] The hot melt adhesive composition according to the present invention is characterized by lower viscosity and higher adhesive strength compared to petroleum-based hot melts, thereby providing excellent adhesive strength to various adhesives. It is particularly suitable for use as PET bottle labels or cosmetic packaging, and can be used as an eco-friendly hot melt adhesive composition with properties equivalent to the excellent grade in the recycling standard for easy recycling.

[0015] Hereinafter, the present invention will be described in detail.

[0016] In the present invention, 'bio-based material' means a material in which a raw material derived from biomass is used in a certain proportion or more for any purpose.

[0017] The above biomass refers to a carbon-neutral material or biodegradable resin commonly known in the field of the present invention.

[0018] According to a preferred embodiment of the present invention, a biodegradable plastic is essentially comprised of a thermoplastic polymer, a tackifier, a plasticizer, a viscosity modifier and an antioxidant, wherein the tackifier, the plasticizer and the viscosity modifier may comprise the bio-based material.

[0019] A detailed description of the above configuration is as follows.

[0020]

[0021] (a) biodegradable plastics

[0022] The hot melt adhesive composition according to the present invention includes polyhydroxyalkanoate (PHA) as a biodegradable plastic.

[0023] Polyhydroxyalkanoate (PHA) is a copolymer of PHB and PHV. PHA is a group of biopolymers produced by microorganisms such as bacteria and algae. PHA is a representative biodegradable plastic material, and its structure and properties can be controlled because it can be synthesized from over 150 different monomers. Notably, it is not only harmless to the human body, but also exhibits superior biodegradability under natural and marine conditions compared to other biodegradable plastic materials. PHA exhibits significant viscosity changes depending on temperature, making it useful as a hot melt adhesive.

[0024] In one embodiment of the present invention, the hot melt adhesive composition according to the present invention may include other biodegradable plastics in addition to PHA.

[0025] The above other biodegradable plastics include, but are not limited to, one or a mixture of cellulose, pectin, chitin, polylactic acid (PLA), polycaprolactone (PCL), polyesterurethane (PEU), aliphatic polyester (AP), aromatic / aliphatic copolyester (Aro / Ali), Bio-PDO (Propanediol), CA (Cellulose Acetate), polyglycolicacid (PGA), polybutylene succinate (PBS), polyhydroxybutyrate (PHB), polyvinyl alcohol (PVA), and thermoplastic starch (TPS). no.

[0026] When a biodegradable plastic according to one embodiment of the present invention is included, it can have excellent environmental friendliness and excellent mechanical properties, viscosity, and tack properties.

[0027]

[0028] (b) thermoplastic polymers

[0029] A hot melt adhesive composition according to the present invention comprises a thermoplastic polymer.

[0030] In the present invention, the thermoplastic polymer has the function of controlling the adhesive strength and cohesive strength of the hot melt adhesive.

[0031] In the present invention, the thermoplastic polymer may include not only one selected from the group consisting of ethylene vinyl acetate copolymer (EVA), polyvinyl acetate, polyvinyl alcohol, ethylene-acrylic acid copolymer, and ethylene-methacrylic acid copolymer, but also rubber (polyisoprene), polybutadiene, synthetic polyisoprene, etc., which are types of elastomeric polymers.

[0032] Specifically, the thermoplastic polymer may be one selected from the group consisting of styrene-butadiene block copolymers, styrene-butadiene-styrene block copolymers, styrene-isoprene block copolymers, styrene-isoprene-benzene secondary alkene block copolymers, styrene-ethylene-butadiene-benzene secondary alkene block copolymers, styrene-isobutylene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-ethylene-ethylene-propylene-styrene block copolymers, styrene ethylene-propylene-styrene block copolymers, and combinations thereof.

[0033] In one embodiment of the present invention, the content of the thermoplastic polymer is not particularly limited, but may be included in an amount of 50 to 200 parts by weight based on 100 parts by weight of the biodegradable plastic. If the content of the thermoplastic polymer is less than 50 parts by weight, there is a problem of reduced initial adhesiveness, and if it exceeds 200 parts by weight, there is a problem of increased viscosity.

[0034]

[0035] (c) adhesive agent

[0036] The hot melt adhesive composition according to the present invention includes a tackifier.

[0037] The above adhesive may include a bio-based material.

[0038] In the present invention, the tackifier may be a compound or a low molecular weight polymer that enhances the adhesive strength of the hot melt adhesive composition.

[0039] In the present invention, the tackifier includes any compatible resin or mixtures thereof, such as natural and modified rosins including at least one selected from the group consisting of gum rosin, wood rosin, tall oil rosin, distilled rosin, hydrogenated rosin, dimerized rosin, rosin esters and polymerized rosins; pentaerythritol esters of natural and modified rosins including at least one selected from the group consisting of glycerol, phenol-modified rosin and rosin esters; monomer resins; polymers and copolymers of natural terpenes such as pinene; terpene resins; hydrogenated polyterpene resins; phenol-modified terpene resins and hydrogenated derivatives thereof; indene-coumarone resins; aliphatic petroleum hydrocarbon resins; hydrogenated aliphatic petroleum hydrocarbon resins; C5 / C9 hydrocarbon resins, aromatic petroleum hydrocarbon resins and hydrogenated derivatives, etc. Specifically, the bio-based material that can be included in the tackifier may include at least one selected from the group consisting of gum rosin, wood rosin, tall oil rosin, distilled rosin, hydrogenated rosin, dimerized rosin, rosin ester and polymerized rosin; pentaerythritol ester of natural and modified rosin including at least one selected from the group consisting of glycerol, phenol-modified rosin and rosin ester; monomer resin; polymer and copolymer of natural terpenes such as pinene; terpene resin; hydrogenated polyterpene resin; phenol-modified terpene resin and hydrogenated derivatives thereof; and at least one selected from the group consisting of: a bio-based material component; and a polymer. In this case, each component mentioned as the bio-based material may include the bio-based material component in a proportion of part or 100 wt% of the total components, depending on the purpose.

[0040] The above adhesive can be used alone as a bio-based material, or can be used in combination with one or more of the above-described petroleum-based materials.

[0041] In one embodiment of the present invention, the content of the tackifier is not particularly limited, but may be included in an amount of 150 to 350 parts by weight based on 100 parts by weight of the biodegradable plastic. If the content of the tackifier is less than 150 parts by weight, there is a problem of reduced initial adhesive strength, and if it exceeds 350 parts by weight, there is a problem of reduced mechanical properties.

[0042]

[0043] (d) plasticizer

[0044] The hot melt adhesive composition according to the present invention includes a plasticizer.

[0045] The above plasticizer may include a bio-based material.

[0046] The plasticizers include polyisobutylene, mineral oil, ethylene propylene diene monomer rubber, liquid hydrocarbon resins, various polyalkylene oxides (e.g., polyethylene oxide or propylene oxide), naphthenic oil, citric acid derivatives, fumaric acid derivatives, glycerol derivatives, isophthalic acid derivatives, lauric acid derivatives, linoleic acid derivatives, maleic acid derivatives, benzoic acid derivatives, phosphoric acid derivatives, sebacic acid derivatives, stearic acid derivatives, succinic acid derivatives, and sulfonic acid derivatives. Specifically, the bio-based material that can be included in the plasticizer may include at least one selected from the group consisting of citric acid derivatives, furmaric acid derivatives, glycerol derivatives, lauric acid derivatives, linoleic acid derivatives, sebacic acid derivatives, stearic acid derivatives, and succinic acid derivatives. In this case, each component mentioned as the bio-based material may include a portion of the total component or a 100 wt% ratio of the bio-based material component depending on the purpose.

[0047] The above plasticizer can be used alone as a bio-based material, or can be used in combination with one or more of the above-described petroleum-based materials.

[0048] In one embodiment of the present invention, the content of the plasticizer is not particularly limited, but may be included in an amount of 100 to 300 parts by weight based on 100 parts by weight of the biodegradable plastic. If the content of the plasticizer is less than 100 parts by weight, there is a problem of insufficient viscosity-reducing effect, and if it exceeds 300 parts by weight, there is a problem of deterioration of mechanical properties.

[0049]

[0050] (e) viscosity modifier

[0051] The hot melt adhesive composition according to the present invention may further include a viscosity modifier.

[0052] The above viscosity modifier may include a bio-based material.

[0053] As the viscosity modifier, paraffin wax, microcrystalline wax, polyethylene wax, polypropylene wax, amide wax, Fischer-Tropsch wax, beeswax, carnauba wax, candelilla wax, rice bran wax, soy wax, etc. can be used. Specifically, the bio-based material that can be included in the viscosity modifier may include one or more kinds composed of beeswax, carnauba wax, candelilla wax, rice bran wax, soy wax; In this case, each component mentioned as the bio-based material may include a part of the total component or a 100 wt% ratio of the bio-based material component depending on the purpose.

[0054] The above viscosity modifier can be used alone as a bio-based material, or can be used in combination with one or more of the above-described petroleum-based materials.

[0055] The viscosity modifier can lower the melting temperature of other polymer resins included in the adhesive composition, while improving fluidity and wettability and controlling the solidification speed of the adhesive composition.

[0056] In one embodiment of the present invention, the content of the viscosity modifier is not particularly limited, but may be included in an amount of 30 to 60 parts by weight based on 100 parts by weight of the biodegradable plastic. If the content of the viscosity modifier is less than 30 parts by weight, the viscosity-reducing effect is insignificant, and if it exceeds 60 parts by weight, there is a problem of reduced initial adhesiveness.

[0057]

[0058] (f) Antioxidants

[0059] The hot melt adhesive composition according to the present invention may further include an antioxidant.

[0060] In one embodiment of the present invention, the antioxidant may be at least one antioxidant selected from a phenol-based antioxidant, an aromatic amine-based antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant. When the antioxidant is further included, the polymer chain scission or crosslinking reaction caused by high temperature or light can be prevented, thereby improving the thermal stability of the adhesive composition.

[0061] In one embodiment of the present invention, the content of the antioxidant is not particularly limited, but may be included in an amount of 1 to 10 parts by weight based on 100 parts by weight of the biodegradable plastic.

[0062]

[0063] According to one embodiment of the present invention, the hot melt adhesive composition of the present invention may have a content of bio-based material of 40 to 90 wt%.

[0064] When the content of bio-based materials is less than 40 wt%, the effect of reducing CO2 emissions is minimal, and when it exceeds 90 wt%, the mechanical properties may be lower than those of petroleum-based hot melt.

[0065] The hot melt adhesive composition according to the present invention has no limited use, but can be used for PET bottle labels or cosmetic packaging.

[0066] Hereinafter, the present invention will be described in more detail through examples. These examples are intended solely to illustrate the present invention more specifically, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples, in accordance with the gist of the present invention.

[0067]

[0068] <Example>

[0069] PHA, thermoplastic polymer, tackifier, plasticizer, viscosity modifier, and antioxidant were measured and mixed at 160-170℃ using a batch internal mixer device (Model: Torque Rheometer System, Manufacturer: MKE (Korea)) to prepare a composition.

[0070]

[0071] <Examples 1 to 5>

[0072] The composition was manufactured by mixing at 160 to 170°C using a batch internal mixer device (Model: Torque Rheometer System, Manufacturer: MKE (Korea)) according to the types and amounts of ingredients listed in Table 1 below.

[0073] <Comparative Example>

[0074] TECHNOMELT EM 598RE, commercially available from Henkel, was used as a comparative example.

[0075]

[0076] Unit: PhrPHASIS Tackifier Plasticizer Viscosity regulator Antioxidant ABCD Comparative Example TECHNOMELT EM 598RE (Henkel) Example 1 100 100 300 250 503 Example 2 100 100 200 200 40 2.4 Example 3 100 150 250 100 60 503 Example 4 100 50 300 140 2003 Example 5 100 50 300 140 140 603

[0077]

[0078] In Table 1 above, the components corresponding to PHA, SIS, adhesive, plasticizer (A, B), viscosity modifier (C, D), and antioxidant are as follows.

[0079] PHA: Polyhydroxyalkanoate PHA (Product name: PHACT A1000P; Supplier: CJ CheilJedang)

[0080] SIS: Styrene-isoprene-styrene block copolymer (Product name: KRATON™ D1161 J Polymer, Supplier: Kraton (USA))

[0081] Tackifier: Rosin Ester (Product Name: SYLVALITE RE 105L Rosin Ester, Supplier: Kraton, Bio-based material content 94 wt%)

[0082] Plasticizer A: Paraffin oil (Product name: Paraffin oil, Supplier: Samjeon Chemical)

[0083] Plasticizer B: Acetyl tributyl citrate (Product name: BPC-137, Supplier: Taoka Chemical, Bio-based material content 100 wt%)

[0084] Viscosity modifier C: Microcrystalline wax (Product name: DNW-170s, Supplier: Dongnam Oil & Chemicals)

[0085] Viscosity modifier D: Carnauba wax (Product name: T-3, Supplier: FONCEPI COMERCIAL EXPORTADORA LTDA.)

[0086] Antioxidant: Tetrakis[methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate]methane (Product name: Songnox 1010, Supplier: Songwon Industrial)

[0087]

[0088] The melt viscosity, initial adhesiveness, and T-Peel tests were performed on the compositions prepared in Examples 1 to 5 and Comparative Examples, and the results are shown in Table 2 below.

[0089]

[0090] <Test method>

[0091] 1) Melt viscosity test

[0092] The melt viscosity of hot melt adhesives was measured using a viscometer (model number: DV2TRV) equipped with a Brookfield Thermosel system. Specifically, 10.5 ml of hot melt adhesive was weighed and placed in the sample chamber, completely melted at approximately 175°C, and the melt viscosity was measured using an SC4-27 or SC4-21 spindle.

[0093] 2) Initial adhesion (ball tack) test

[0094] Measurements were made in compliance with the test standard KS-T-1028, and the inclined ball tack test was performed by fixing the test specimen on an inclined plate at an angle of 20° to 40°, and then rolling the ball specified in KS B 2001 on it to measure the initial adhesive strength of the specimen using the ball's unique value (size) and angle.

[0095] 3) T-Peel test

[0096] Measurements were made in compliance with the test standard KS-T-1028. After compressing the test piece, it was left to rest for more than 5 minutes, and the test plate was inserted into a jig horizontally attached to the lower jaw of the tensile tester, and one end of the remaining part was inserted into the upper jaw. Next, it was continuously pulled and peeled at a speed of (300±30) mm / min, and four points were measured at 20 mm intervals. The result was recorded as the average value of 12 points measured with three test pieces.

[0097]

[0098] Melting viscosity (175°C) Initial adhesion (0.1t, 00~30°, No. 2~32) T-Peel (N / mm) Bio-based material (wt%) Comparative example 4555°, No. 135.060 Example 1 16430°, No. 117.6854.0 Example 2 31830°, No. 159.9851.0 Example 3 48830°, No. 227.8961.0 Example 4 24820°, No. 155.0971.0 Example 5 31620°, No. 184.7186.0

[0099]

[0100] Bio-based material (wt%): (Weight of bio-based material / Weight of total composition) * 100

[0101] <Experimental Results>

[0102] The experimental results according to the above analysis are important items for evaluating the suitability as a hot melt adhesive for PET bottle labels or cosmetic packaging.

[0103] As shown in Table 2 above, it was found that the compositions of Examples 1 to 5 according to the present invention had superior melt viscosity, initial adhesive strength, and T-Peel characteristics compared to the comparative examples using TECHNOMELT EM 598RE.

[0104] In particular, from the results of Examples 1 and 2, it was confirmed that although the effect of reducing viscosity can be observed when the amount of thermoplastic polymer is reduced, there is a disadvantage that the initial adhesive strength and mechanical properties are reduced.

[0105] In Examples 3 to 5, it was also confirmed that the viscosity of the hot melt adhesive could be reduced by applying acetyl tributyl citrate and carnauba wax.

[0106] As a result of the test, it was confirmed that a composition comprising a PHA resin, a thermoplastic polymer, a tackifier, a viscosity modifier, and a plasticizer according to the present invention can realize a hot melt adhesive having mechanical properties, viscosity, tack properties, etc. that are equivalent to or higher than those of commercially available petroleum-based hot melt adhesives, and a bio-based material content of 40 to 90 wt%.

Claims

1. Contains biodegradable plastics, thermoplastic polymers, tackifiers and plasticizers; The above biodegradable plastic contains polyhydroxyalkanoate (PHA). Hot melt adhesive composition.

2. In paragraph 1, The biodegradable plastic further comprises one or more of cellulose, pectin, chitin, polylactic acid (PLA), polycaprolactone (PCL), polyesterurethane (PEU), aliphatic polyester (AP), aromatic / aliphatic copolyester (Aro / Ali), Bio-PDO (Propanediol), CA (Cellulose Acetate), polyglycolic acid (PGA), polybutylene succinate (PBS), polyhydroxybutyrate (PHB), polyvinyl alcohol (PVA), and thermoplastic starch (TPS), or a mixture thereof. Hot melt adhesive composition.

3. In paragraph 1, The thermoplastic polymer is one selected from the group consisting of styrene-butadiene block copolymers, styrene-butadiene-styrene block copolymers, styrene-isoprene block copolymers, styrene-isoprene-benzene secondary alkene block copolymers, styrene-ethylene-butadiene-benzene secondary alkene block copolymers, styrene-isobutylene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-ethylene-ethylene-propylene-styrene block copolymers, styrene ethylene-propylene-styrene block copolymers, and combinations thereof. Hot melt adhesive composition.

4. In paragraph 1, The plasticizer is at least one selected from the group consisting of polyisobutylene, mineral oil, ethylene propylene diene monomer rubber, liquid hydrocarbon resin, polyethylene oxide or propylene oxide, naphthenic oil, citric acid derivatives, fumaric acid derivatives, glycerol derivatives, isophthalic acid derivatives, lauric acid derivatives, linoleic acid derivatives, maleic acid derivatives, benzoic acid derivatives, phosphoric acid derivatives, sebacic acid derivatives, stearic acid derivatives, succinic acid derivatives, and sulfonic acid derivatives. Hot melt adhesive composition.

5. In paragraph 1, A hot melt adhesive composition further comprising a viscosity modifier.

6. In paragraph 5, A hot melt adhesive composition wherein the viscosity modifier is a wax.

7. In paragraph 1, A hot melt adhesive composition further comprising an antioxidant.

8. In paragraph 1 or paragraph 5, A hot melt adhesive composition wherein the biodegradable plastic, tackifier, plasticizer and viscosity modifier each contain a bio-based material.

9. In paragraph 8, The above composition is a hot melt adhesive composition having a content of 40 to 90 wt% of a bio-based material.

10. In paragraph 1, The above composition is a hot melt adhesive composition used for PET bottle labels or cosmetic packaging purposes.