Bio-based Acrylate Monomers

Abstract

The present invention relates to a compound having the following structure: JPEG2022550359000009.jpg49107, where R1 is H or CH3, and R2 is a linear C1-C10 alkyl or a branched C3-C10 alkyl.

Description

[Technical field]

[0001] FIELD OF THE PRESENT ART The present invention relates to bio-based acrylate monomers. [Background technology]

[0002] 2. Background of the Invention (Meth)acrylate adhesives are mainly composed of (meth)acrylate monomers and oligomers. There is a constant need for new (meth)acrylate monomer and oligomer structures with new technical properties, such as low odor and low vapor pressure monomers to improve the production line and the health and safety of the end user.

[0003] These (meth)acrylate monomers and oligomers are traditionally produced using petroleum-based feedstocks. To increase sustainability, end-users of (meth)acrylate adhesives are increasingly looking for products with an increased bio-based content without compromising performance. Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, there is a demand for novel (meth)acrylate monomers that can be obtained by increasing the amount of bio-based raw materials without compromising the desired physical properties and performance. [Means for solving the problem]

[0005] Summary of the Invention The present invention relates to a compound having the following structure: JPEG0007603672000001.jpg49104 [wherein R1 is H or -CH3, and R2 is a linear C1-C10 alkyl or a branched C3-C10 alkyl] The present invention relates to a compound having the formula:

[0006] The present invention also relates to a method of producing the compounds of the present invention by reacting a bio-based alkyl-2-hydroxy-3-butenoate with (meth)acryloyl chloride or (meth)acrylic acid or (meth)acrylic anhydride, where alkyl is a linear C1-C10 alkyl or a branched C3-C10 alkyl.

[0007] The present invention includes adhesive compositions containing compounds according to the present invention.

[0008] The invention further encompasses the use of the compounds according to the invention as reactive acrylate monomers in structural bonding adhesives, acrylic pressure sensitive adhesives, water-based acrylic dispersions, anaerobic acrylic adhesives or 3D printing resins. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Detailed Description In the following text, the present invention will be described in more detail. Each aspect so described can be combined with any other aspect or aspects, unless expressly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

[0010] In the present invention, the terms used are to be construed in accordance with the following definitions, unless the context dictates otherwise.

[0011] As used herein, the singular forms "a," "an," and "the" include both singular and plural referents unless the context clearly dictates otherwise.

[0012] As used herein, the terms "comprising," "comprises," and "comprised of" are synonymous with "including," "includes," or "containing," and are inclusive or open-ended and do not exclude additional, unrecited components, elements, or method steps.

[0013] It should be noted that the numerical endpoints are intended to include all numbers, fractions and fractions subsumed within each range.

[0014] All percentages, parts, ratios, etc. referred to herein are by weight unless otherwise specified.

[0015] When an amount, concentration, or other value or parameter is expressed in the form of a range, preferred range, upper preferred value, or lower preferred value, it should be understood that the range obtained by combining any upper or preferred value with any lower or preferred value is specifically disclosed, regardless of whether the resulting range is clearly stated in the context.

[0016] All documents cited herein are incorporated by reference in their entirety.

[0017] Unless otherwise defined, all terms used in disclosing the present invention, including technical and scientific terms, have the meanings commonly understood by one of ordinary skill in the art to which this invention belongs. As a further guide, definitions of terms are included to better understand the teachings of the present invention.

[0018] The present invention relates to a compound having the following structure: JPEG0007603672000002.jpg50107 [wherein R1 is H or -CH3, and R2 is a linear C1-C10 alkyl or a branched C3-C10 alkyl] The present invention relates to a compound having the formula:

[0019] Preferably, R1 is -CH3 and R2 is selected from a methyl group, an ethyl group and an isopropyl group, preferably R2 is a methyl group.

[0020] In a highly preferred embodiment, R1 is -CH3 and R2 is -CH3.

[0021] Compounds I and II according to the present invention are bio-based molecules and therefore desirable. They also provide lower shrinkage in adhesive and coating applications. Furthermore, the addition of vinyl functionality allows for further modification and tuning of properties (further crosslinking, thiolene reaction, etc.). Compounds I and II where R1 is -CH3 and R2 is -CH3 group are slightly less reactive than compounds I and II where R1 is H.

[0022] Compounds with structures I and II, where R1 is -CH3 and R2 is -CH3, have higher boiling points resulting in higher flash points compared to other acrylate monomers such as MMA, thus improving the safety profile of the compounds. Furthermore, compounds with structures I and II, where R1 is -CH3 and R2 is -CH3, have lower viscosities, which makes the compounds easier to handle and use in adhesive compositions. Furthermore, compounds with structure I are particularly preferred due to the more reactive double bonds. The vinyl bond is a very important feature, as it can be used for further chemical modifications such as sulfur or peroxide crosslinking and thiol-ene reactions. Furthermore, the vinyl bond participates in conventional radical-mediated crosslinking reactions.

[0023] In a highly preferred embodiment, the compound has the structure: TIFF0007603672000003.tif4136 [Wherein, R1 is -CH3 and 、 R2 is -CH3] has.

[0024] In another highly preferred embodiment, the compound has the structure: TIFF0007603672000004.tif4136 [In the formula, R1 is -CH3 and R2 is -CH3] has.

[0025] The compound alkyl-2-hydroxy-3-butenoate (1), where alkyl (R2 in structures I and II) is a linear C1-C10 alkyl or a branched C3-C10 alkyl, preferably selected from methyl, ethyl and isopropyl groups, more preferably methyl groups, is used as the starting material to produce a compound having structure I or II.

[0026] Compounds having structure I or II are prepared by reacting a biobased alkyl-2-hydroxy-3-butenoate (1) with (meth)acryloyl chloride (2) or (meth)acrylic acid (3) or (meth)acrylic anhydride (4), as shown in Scheme 1 below.

[0027] TIFF0007603672000005.tif139130 Scheme 1

[0028] Biobased alkyl-2-hydroxy-3-butenoates (1) can be obtained from sugar streams. In principle, lactic acid, 2-hydroxy-3-butenoic acids and esters can be produced by converting glucose, fructose, sucrose, xylose, or glycoaldehyde in a solvent in the presence of a solid Lewis acid catalyst (details of the process are disclosed in EP2184270). The solvent used in the process promotes the formation of the alkyl group (R2 in structures I and II). If the reaction is carried out in methanol, the alkyl (R2) is -CH3, but if ethanol is used, a -CH2CH3 group is produced as the alkyl (R2), and isopropyl produces -CH(CH3)2 as the alkyl (R2). If the process is carried out in biobased MeOH or biobased EtOH, 100% biobased methyl-2-hydroxy-3-butenoate or ethyl-2-hydroxy-3-butenoate can be obtained.

[0029] Commercially available methyl-2-hydroxy-3-butenoate is currently available from fine chemical producers in the United States, Europe, or Asia, such as, for example, ABCR GmbH or Chemo GmbH.

[0030] Commercially available (meth)acryloyl chlorides suitable for use in the present invention include, but are not limited to, methacryloyl chloride from Acros.

[0031] Commercially available (meth)acrylic acids suitable for use in the present invention include, but are not limited to, methacrylic acid from Sigma-Aldrich.

[0032] Commercially available (meth)acrylic anhydrides suitable for use in the present invention include, but are not limited to, (meth)acrylic anhydride from Sigma-Aldrich.

[0033] In a preferred embodiment, the compound having structure I or II is produced by a process in which biobased methyl-2-hydroxy-3-butenoate (1) is reacted with (meth)acryloyl chloride (2) or (meth)acrylic acid (3) or (meth)acrylic anhydride (4) in the presence of a catalyst.

[0034] Suitable catalysts for use in the present invention are non-nucleophilic bases, preferably groups from the group consisting of tertiary amines having the structure NR3, where R3 is an alkyl group, triethylamine, N,N-diisopropylethylamine (DIPEA), 1,8-diazabicycloundec-7-ene (DBU), 1,5-diazabicyclo(4.3.0)non-5-ene (DBN), 2,6-di-tert-butylpyridine, phosphazene bases such as t-Bu-P4, lithium diisopropylamide, sodium bis(trimethylsilyl)amide (NaHMDS), potassium bis(trimethylsilyl)amide (KHMDS), lithium tetramethylpiperidide (LiTMP) and mixtures thereof, preferably triethylamine, 1,8-diazabicycloundec-7-ene (DBU) and mixtures thereof, more preferably the catalyst is triethylamine.

[0035] The catalyst influences the ratio of structures I and II, which are the major and minor products. Triethylamine is the preferred catalyst because it promotes the formation of structure I as the major product.

[0036] In addition to the choice of catalyst, the reaction conditions and purity of the reagents all affect the ratio of structures I and II.

[0037] The reaction is carried out in an aprotic organic solvent. Solvents suitable for use in the present invention are selected from the group consisting of dichloromethane, hexane, benzene, toluene, 1,4-dioxane, chloroform, diethyl ether, N-methylpyrrolidone, tetrahydrofuran, ethyl acetate, acetone, dimethylformamide, acetonitrile, dimethylsulfoxide, propylene carbonate, and mixtures thereof.

[0038] The compounds having structure I or II according to the present invention are polymerizable monomers and can be used as polymerizable components for adhesives. Structures I and II can be used alone or together as polymerizable components for adhesives.

[0039] The compounds having structures I and / or II can be used as part of an adhesive composition. In one embodiment, the adhesive composition comprises a compound having structures I and / or II according to the present invention.

[0040] One embodiment according to the present invention is directed to an adhesive composition in which structures I and II are both present, preferably in a ratio of I:II of 99.99%:0.001% to 0.001%:99.99%.

[0041] In one embodiment, the adhesive comprises a compound having structure I and / or II according to the present invention, an acrylate monomer and / or oligomer, and a radical initiator. The adhesive can be cured by heat and / or UV.

[0042] Suitable adhesives may be structural bonding adhesives such as 2K reactive adhesives; acrylic pressure sensitive adhesives; anaerobic acrylic adhesives such as thread locker; water-based acrylic dispersions or 3D printing resins.

[0043] Compounds having Structure I and / or II can be used as reactive acrylate monomers in structural bonding adhesives such as 2K reactive adhesives; acrylic pressure sensitive adhesives; anaerobic acrylic adhesives such as thread lockers; water-based acrylic dispersions or 3D printing resins. EXAMPLES

[0044] Example 1 56.2 g (0.49 Mol) of methyl-2-hydroxy-3-butenoate (only available from fine chemical manufacturers such as ABCRGmbH or ChemoS GmbH) was added to dichloromethane, followed by treatment with 56.3 g (0.60 Mol) of triethylamine (from Merck) and cooling to 0-3 °C. 60.3 g (0.60 Mol) of methacryloyl chloride (from Acros) was added within 15 min and the mixture was stirred for 2 h, during which the solution turned red. The solvent was evaporated on a rotary evaporator, the concentrate was mixed with dichloromethane and washed three times with water. The organic phase was dried with sodium sulfate and concentrated. The concentrate obtained was a transparent, viscous substance of dark red color. The concentrate obtained was mixed with 0.2 g of BHT and distilled in a short Vigreux column at high vacuum with a bath temperature of up to 95 °C, samples were collected at 50-52 °C. 57.2g of a colorless water thin liquid was produced, which had little strong odor like monomers such as MMA. The structure and purity of the compound were confirmed by NMR. Under these reaction conditions, 15% (+ / - 3%) of compound II and 85% of compound I were obtained.

[0045] Example 2 The compound obtained from Example 1 was mixed with 3% by weight of Irgacure 2959 (from Ciba Shiepital Chemicals). Before mixing, Irgacure 2959 was pre-dissolved in acetone. The mixture was heated to remove the acetone. The resulting clear solution was placed in an aluminum cup and subsequently irradiated in a UV chamber for 5 minutes. The composition was cured into a film with a Tg of about 64°C. The cured film was less brittle than a film formed from MMA.

[0046] Table 1 below lists the physical properties of a mixture of Compound I (88%) and Compound II (12%) according to the invention. The properties are compared to those of methyl methacrylate.

[0047] Compounds I and II according to the present invention have a higher boiling point resulting in lower vapor pressure, better health and safety when handling the compounds; less aggressive odor; lower shrinkage for increased adhesion in critical applications; additional vinyl / double bond functionality gives the possibility for further crosslinking / chemical modification; finally, due to the different structure, different properties can be expected in terms of Tg, adhesion, solubility, compatibility etc.

[0048] [Table 1] Preferred aspects of the invention include the following. [1] The following structure TIFF0007603672000007.tif50108 [In the formula, R 1 is H or CH 3 and R 2 is a straight chain C1-C10 alkyl or a branched C3-C10 alkyl. A compound having the formula: [2] The above R 1 Ha-CH 3 and R 2 is selected from the group consisting of methyl, ethyl and isopropyl groups, preferably R 2 is a methyl group. [3] The structure is Structure I, wherein R 1 Ha-CH 3 and R 2 Ha-CH 3 The compound according to [1] or [2], [4] The structure is Structure II, R 1 Ha-CH 3 and R 2 Ha-CH 3 The compound according to [1] or [2], [5] A method for producing the compound according to any one of [1] to [4], comprising reacting a bio-based alkyl-2-hydroxy-3-butenoate with (meth)acryloyl chloride or (meth)acrylic acid or (meth)acrylic anhydride, wherein the alkyl is a linear C1-C10 alkyl or a branched C3-C10 alkyl. [6] The method according to [5], wherein the bio-based alkyl-2-hydroxy-3-butenoate is reacted with (meth)acryloyl chloride or (meth)acrylic acid or (meth)acrylic anhydride in the presence of a catalyst, wherein the alkyl is a linear C1-C10 alkyl or a branched C3-C10 alkyl. [7] An adhesive composition comprising a compound having the structure I and / or II according to any one of [1] to [4]. [8] The adhesive composition according to [7], wherein the structures I and II are both present, preferably in a ratio I:II of 99.99%:0.001% to 0.001%:99.99%. [9] The adhesive composition according to [7] or [8], wherein the adhesive is a structural bonding adhesive, an acrylic pressure-sensitive adhesive, an anaerobic acrylic adhesive, an acrylic dispersion, or a 3D printing resin.

[10] Use of the compound according to any one of [1] to [4] as a reactive acrylate monomer in a structural bonding adhesive, an acrylic pressure-sensitive adhesive, an anaerobic acrylic adhesive, an aqueous acrylic dispersion or a 3D printing resin.

Claims

1. The following structure: [In the formula, R １ is H or CH ３ and R ２ is a straight chain C1-C10 alkyl or a branched C3-C10 alkyl. A compound having the formula:

2. The R １ Ha-CH ３ and R ２ The compound of claim 1 , wherein is selected from a methyl group, an ethyl group, and an isopropyl group.

3. The structure is Structure I, where R １ Ha-CH ３ and R ２ Ha-CH ３ 3. The compound according to claim 1 or 2,

4. The structure is Structure II, and R １ Ha-CH ３ and R ２ Ha-CH ３ 3. The compound according to claim 1 or 2,

5. 5. A method for preparing the compound according to any one of claims 1 to 4, comprising reacting a bio-based alkyl-2-hydroxy-3-butenoate with (meth)acryloyl chloride or (meth)acrylic acid or (meth)acrylic anhydride, wherein the alkyl is a linear C1-C10 alkyl or a branched C3-C10 alkyl.

6. 6. The method of claim 5, wherein the bio-based alkyl-2-hydroxy-3-butenoate is reacted with (meth)acryloyl chloride or (meth)acrylic acid or (meth)acrylic anhydride in the presence of a catalyst, wherein the alkyl is a linear C1-C10 alkyl or a branched C3-C10 alkyl.

7. An adhesive composition comprising a compound having structure I and / or II according to any one of claims 1 to 4.

8. The adhesive composition of claim 7 , wherein said structures I and II are both present.

9. 9. The adhesive composition of claim 7 or 8, wherein the adhesive is a structural bonding adhesive, an acrylic pressure sensitive adhesive, an anaerobic acrylic adhesive, an acrylic dispersion, or a 3D printing resin.

10. 5. Use of the compound according to any one of claims 1 to 4 as a reactive acrylate monomer in a structural bonding adhesive, an acrylic pressure sensitive adhesive, an anaerobic acrylic adhesive, an aqueous acrylic dispersion or a 3D printing resin.

Images