阅读说明：本技术 一种聚氨酯改性丙烯酸酯uv树脂及其制备方法 (Polyurethane modified acrylate UV resin and preparation method thereof ) 是由 徐涛 龙绪俭 熊东路 肖增钧 易松 杨轩 李斌仁 鲁晓东 于 2020-05-08 设计创作，主要内容包括：本发明涉及UV树脂相关的技术领域,更具体地,本发明提供一种聚氨酯改性丙烯酸酯UV树脂及其制备方法,所述制备方法,包括如下步骤：将二异氰酸酯加入反应瓶中,升温至50～70℃,滴加二元醇,反应,降温得到产物A；避光条件下,将丙烯酸酯单体加入反应瓶中,升温,再缓慢滴加乙醇胺,反应,降温得到产物B；氩气保护,避光条件下,将产物B加入反应瓶中,升温至50～70℃,滴加产物A,反应,降温即得所述聚氨酯改性丙烯酸酯UV树脂。本发明提供的聚氨酯改性丙烯酸酯UV树脂,解决传统紫外固化涂料附着力以及韧性差的问题,可以较好保持所得涂层硬度以及附着力,提高了耐磨性以及柔韧性,此外,所得固化漆膜外观光滑、无色透明、饱满。(The invention relates to the technical field related to UV resin, and more particularly provides polyurethane modified acrylate UV resin and a preparation method thereof, wherein the preparation method comprises the following steps: adding diisocyanate into a reaction bottle, heating to 50-70 ℃, dropwise adding dihydric alcohol, reacting, and cooling to obtain a product A; under the condition of keeping out of the sun, adding an acrylate monomer into a reaction bottle, heating, slowly dropwise adding ethanolamine, reacting, and cooling to obtain a product B; and under the protection of argon and in a dark condition, adding the product B into a reaction bottle, heating to 50-70 ℃, dropwise adding the product A, reacting, and cooling to obtain the polyurethane modified acrylate UV resin. The polyurethane modified acrylate UV resin provided by the invention solves the problem of poor adhesive force and toughness of the traditional UV curing coating, can well maintain the hardness and adhesive force of the obtained coating, improves the wear resistance and flexibility, and has a smooth, colorless, transparent and full appearance of the obtained cured paint film.)

1. A polyurethane modified acrylate UV resin is characterized in that the structural formula is shown as a general formula (1),

r in the general formula (1) is an ether structure; r₁Containing an aromatic ring structure or a six-membered ring structure; r₂、R₃Are independently acrylate structures.

2. The urethane-modified acrylate UV resin according to claim 1, wherein R in the general formula (1) is selected from the group consisting ofAny one or more combinations of; wherein n is 3-20, n₁1 to 30, n₂Is 2 to 40.

3. The urethane-modified acrylate UV resin according to claim 1, wherein R in the general formula (1)₁Is selected from Any one or more combinations thereof.

4. The urethane-modified acrylate UV resin according to claim 1, wherein R in the general formula (1)₂、R₃The structures are respectively and independently general formula (2) orA compound of the general formula (3),

r in the general formula (2)₅Is of ether structure, R₄Is methyl or hydrogen;

r in the general formula (3)₆Is an ether structure and/or a methylene group.

5. The urethane-modified acrylate UV resin according to claim 4, wherein R in the general formula (2)₅Is selected fromAny one or more combinations of; wherein m is 2-20; m is₁1 to 30; m is₂Is 2 to 30.

6. The urethane-modified acrylate UV resin according to claim 4, wherein R in the general formula (2)₆Is selected fromAny one or more combinations of; wherein p is 1-30; p is a radical of₁Is 1 to 30.

7. The method for preparing the urethane-modified acrylate UV resin according to any one of claims 1 to 6, comprising the steps of:

(1) adding diisocyanate into a reaction bottle, heating to 50-70 ℃, dropwise adding dihydric alcohol, reacting, and cooling to obtain a product A;

(2) under the condition of keeping out of the sun, adding an acrylate monomer into a reaction bottle, heating, slowly dropwise adding ethanolamine, reacting, and cooling to obtain a product B;

(3) and under the protection of argon and in a dark condition, adding the product B into a reaction bottle, heating to 50-70 ℃, dropwise adding the product A, reacting, and cooling to obtain the polyurethane modified acrylate UV resin.

8. The method for preparing the urethane-modified acrylate UV resin according to claim 7, wherein the diol is an alkoxy ether having a number average molecular weight of 500 to 2500; preferably, the dihydric alcohol is polyethylene glycol and/or polypropylene glycol.

9. The method for preparing the urethane-modified acrylate UV resin according to claim 7 or 8, wherein the acrylate monomer is a trifunctional acrylate monomer and/or a difunctional acrylate monomer.

10. A use method of the polyurethane modified acrylate UV resin as claimed in any one of claims 1 to 6, characterized in that the resin, the reactive diluent and the initiator are blended, stirred, coated on a PC-ABS plate and tinplate, and then cured by a UV machine to form a coating film.

Technical Field

The invention relates to the technical field related to UV resin, and particularly provides polyurethane modified acrylate UV resin and a preparation method thereof.

Background

Ultraviolet curing is a chemical method for curing liquid materials, and a coating cured by ultraviolet light is called an ultraviolet curing coating and is widely used for coating wood products, alloys, prepackaged products, plastic products and the like. The coating has unique advantages, such as high curing speed, and can meet the requirement of occasions requiring rapid curing; the environmental impact is low, the solid content can reach 100 percent, and no VOC is discharged; low energy consumption, only radiation energy and no need of heating to remove water or organic solvent.

The UV resin is a main film forming substance of the ultraviolet curing coating and has a key influence on the film coating performance. The structure, functionality, activity and shrinkage of the UV resin determine the curing speed, hardness, adhesion, etc. of the coating film. Although the coating film of the epoxy acrylic UV resin is high in hardness, the adhesion and toughness are poor, and the coating film is greatly limited in the actual use process, so that the invention provides the polyurethane modified acrylate UV resin, and the coating film formed by the polyurethane modified acrylate UV resin has good adhesion and wear resistance, and the toughness and hardness are adjustable.

Disclosure of Invention

In view of the above technical problems, the first aspect of the present invention provides a polyurethane modified acrylate UV resin, the structural formula of which is general formula (1),

r in the general formula (1) is an ether structure; r₁Containing an aromatic ring structure or a six-membered ring structure; r₂、R₃Are independently acrylate structures.

As a preferable embodiment of the present invention, R in the general formula (1) is selected from Any one or more combinations of; wherein n is 3-20, n₁1 to 30, n₂Is 2 to 40.

As a preferable embodiment of the present invention, R in the general formula (1)₁Is selected from Any one or more combinations thereof.

As a preferable embodiment of the present invention, R in the general formula (1)₂、R₃The structures are respectively and independently general formula (2) or general formula (3),

r in the general formula (2)₅Is of ether structure, R₄Is methyl or hydrogen;

r in the general formula (3)₆Is an ether structure and/or a methylene group.

As a preferred embodiment of the present invention, R in the general formula (2)₅Is selected from Any one or more combinations of; wherein m is 2-20; m is₁1 to 30; m is₂Is 2 to 30.

As a preferred embodiment of the present invention, R in the general formula (2)₆Is selected from Any one or more combinations of; wherein p is 1-30; p is a radical of₁Is 1 to 30.

The second aspect of the invention provides a preparation method of the polyurethane modified acrylate UV resin, which comprises the following steps:

(1) adding diisocyanate into a reaction bottle, heating to 50-70 ℃, dropwise adding dihydric alcohol, reacting, and cooling to obtain a product A;

(2) under the condition of keeping out of the sun, adding an acrylate monomer into a reaction bottle, heating, slowly dropwise adding ethanolamine, reacting, and cooling to obtain a product B;

(3) and under the protection of argon and in a dark condition, adding the product B into a reaction bottle, heating to 50-70 ℃, dropwise adding the product A, reacting, and cooling to obtain the polyurethane modified acrylate UV resin.

In a preferred embodiment of the present invention, the diisocyanate is selected from any one or a combination of toluene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, dimethylbiphenyl diisocyanate, and diphenylmethane diisocyanate.

As a preferred technical scheme of the invention, the dihydric alcohol is alkoxy ether, and the number average molecular weight of the alkoxy ether is 500-2500; preferably, the dihydric alcohol is polyethylene glycol and/or polypropylene glycol.

As a preferred technical scheme of the invention, the acrylate monomer is a trifunctional acrylate monomer and/or a difunctional acrylate monomer.

The third aspect of the invention provides a using method of the polyurethane modified acrylate UV resin, which comprises the steps of blending the resin, a reactive diluent and an initiator, stirring, coating on a PC-ABS plate and a tinplate, and curing by a UV machine to form a coating film.

Compared with the prior art, the invention has the following beneficial effects:

(1) the polyurethane modified acrylate UV resin with the polyurethane chain segment structure in the middle and the acrylate structure with at least one double bond at two ends is designed and prepared, so that the wear resistance and flexibility of the obtained paint film are effectively improved while better curing efficiency, adhesive force and hardness are maintained;

(2) the prepared polyurethane modified acrylate UV resin can be used for debugging the structures and molecular weights of different chain segments according to the performance requirements of the cured resin, so that the required polyurethane modified acrylate UV resin is obtained;

(3) the paint film material prepared by adopting the polyurethane modified acrylate UV resin has smooth and full surface and is colorless and transparent, and the application of the paint film material in different fields is expanded.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.

The invention mainly provides a novel polyurethane modified acrylate UV resin, which solves the problem of poor adhesive force and toughness of the traditional ultraviolet curing coating, and simultaneously maintains the curing efficiency of the resin material, better maintains the hardness of the obtained coating, and improves the wear resistance and the flexibility.

The invention provides a polyurethane modified acrylate UV resin with a structural formula of general formula (1),

r in the general formula (1) is an ether structure; r₁Containing an aromatic ring structure or a six-membered ring structure; r₂、R₃Are independently acrylate structures. The invention designs the molecular structure of the polyurethane modified acrylate, wherein R of a polyether structure is a structural chain segment formed by reacting polyether polyol containing hydroxyl with isocyanate groups in polyurethane; r having an aromatic ring structure or a six-membered ring structure₁Is a structural chain segment formed by the reaction of isocyanate containing-NCO and polyether polyol; and R attached to N at both ends of the molecule₂、R₃Is an acrylate segment structure for UV curing.

In one embodiment, R in formula (1) is selected from Any one or more of the groupsCombining; wherein n is 3-20, n₁1 to 30, n₂2 to 40; e.g. n₁10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, etc.; n is₂8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, etc. The R ether structure in the invention is a chain segment structure formed by reacting linear polyethylene glycol, polypropylene glycol with a methyl side chain or linear alkyl ether substances.

In one embodiment, R₁Is selected from Any one or more combinations thereof. R in the invention₁The polyurethane chain segment structure is a chain segment containing an aromatic ring or a six-membered ring, is a molecular structure formed after diisocyanate containing a cyclic structure is reacted, and forms a polyurethane chain segment structure together with an ether group chain segment structure of a straight chain or a short side chain.

In one embodiment, R in formula (1)₂、R₃The structures are respectively and independently general formula (2) or general formula (3),

r in the general formula (2)₅Is of ether structure, R₄Is methyl or hydrogen;

r in the general formula (3)₆Is an ether structure and/or a methylene group.

The tail ends of the two ends of the molecule of the polyurethane modified acrylate provided by the invention are acrylate structures, wherein the acrylate structures can be formed by (methyl) acrylic acid and ether polyols, and can be directly prepared by self or purchased directly, and the acrylate structure at the tail end of the obtained polyurethane modified acrylate at least contains one double bond for UV curing.

In one embodiment, in the general formula (2)R of (A) to (B)₅Is selected from Any one or more combinations of; wherein m is 2-20; m is₁1 to 30; m is₂2 to 30; for example, m is 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, etc.; m is₁Is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, etc.; m is₂2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, etc.

In one embodiment, R in formula (2)₆Is selected from Any one or more combinations of; wherein p is 1-30; p is a radical of₁1 to 30; for example, p is 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, etc.; p is a radical of₁2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, etc.

The polyurethane modified acrylate UV resin designed in the invention adopts the molecular design of an acrylate structure with a polyurethane chain segment structure in the middle and at least one double bond at two ends, and the polyurethane chain segment contains a flexible molecular chain segment of polypropylene glycol with a straight chain or a short side chain and two ends of a rigid molecule with a ring structure, and the combined action of different molecular structures and the chain segment structure keeps the curing efficiency of the obtained cured resin material and the hardness and the adhesive force of the obtained coating, improves the wear resistance and the flexibility, and can debug the structures and the molecular weights of different chain segments according to the performance requirements of the cured resin, thereby obtaining the required polyurethane modified acrylate UV resin.

The second aspect of the invention provides a preparation method of the polyurethane modified acrylate UV resin, which comprises the following steps:

(1) adding diisocyanate into a reaction bottle, heating to 50-70 ℃, dropwise adding dihydric alcohol, reacting, and cooling to obtain a product A;

(2) under the condition of keeping out of the sun, adding an acrylate monomer into a reaction bottle, heating, slowly dropwise adding ethanolamine, reacting, and cooling to obtain a product B;

(3) and under the protection of argon and in a dark condition, adding the product B into a reaction bottle, heating to 50-70 ℃, dropwise adding the product A, reacting, and cooling to obtain the polyurethane modified acrylate UV resin.

Preferably, the preparation method of the polyurethane modified acrylate UV resin comprises the following steps:

(1) adding diisocyanate into a reaction bottle, heating to 50-70 ℃, stirring, dropwise adding dihydric alcohol, continuing to perform heat preservation reaction for 3-5 hours after dropwise adding is finished, stopping the reaction, and cooling to obtain a product A;

(2) under the condition of keeping out of the sun, adding an acrylate monomer into a reaction bottle, heating, stirring, slowly dropwise adding ethanolamine, after dropwise adding, continuing to perform heat preservation reaction for 1-2 days, stopping the reaction, and cooling to obtain a product B;

(3) and under the protection of argon and in the dark condition, adding the product B into a reaction bottle, heating to 50-70 ℃, stirring, dropwise adding the product A, continuing to perform heat preservation reaction for 3-5 hours after dropwise adding is finished, stopping the reaction, and cooling to obtain the polyurethane modified acrylate UV resin.

Preferably, the molar ratio of diol to diisocyanate is 1: (2-2.2); the molar ratio of the acrylate monomer to the ethanolamine is (1.95-2.1): 1.

in one embodiment, the diisocyanate is selected from any one or combination of toluene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, dimethylbiphenyl diisocyanate, diphenylmethane diisocyanate; toluene diisocyanate is preferred.

In one embodiment, the diol is an alkoxy ether having a number average molecular weight of 500 to 2500; preferably, the dihydric alcohol is polyethylene glycol and/or polypropylene glycol; further preferably, the diol is polypropylene glycol-1000 and \ or polypropylene glycol-2000. According to the preparation method, linear polypropylene glycol is adopted to react with isocyanate with a ring structure, and then ethanolamine is used for bridging acrylate, so that the hardness and the adhesive force of the obtained material are kept, and the flexibility and the wear resistance of the material are improved.

In the preparation process of the polyurethane modified acrylate UV resin provided by the application, diisocyanate and dihydric alcohol are adopted to react to form a corresponding polyurethane-containing structureWherein the diisocyanate used contains R₁The diol used has a segment structure of R.

In one embodiment, the acrylate monomer is a trifunctional acrylate monomer and/or a difunctional acrylate monomer; the trifunctional or difunctional groups mean that the acrylate monomers respectively contain three double-bond groups or two double-bond groups.

Preferably, the acrylate monomer is selected from any one or more of tripropylene glycol diacrylate (CAS: 42978-66-5), trimethylolpropane triacrylate (CAS: 15625-89-5), 3-ethoxy-trimethylolpropane triacrylate (CAS: 28961-43-5), propoxytrimethylolpropane triacrylate (CAS: 53879-54-2), bisphenol A diacrylate, hexanediol diacrylate; in one embodiment, the acrylate monomer is tripropylene glycol diacrylate and/or trimethylolpropane triacrylate; in another embodiment, the molar ratio of tripropylene glycol diacrylate to trimethylolpropane triacrylate is 1: (0.95-1.05).

The application utilizes the reaction of acrylate monomer and ethanolamine to form the structure ofOf substance B, wherein R₂、R₃With R in the structure of polyurethane modified acrylate UV resin₂、R₃And (2) reacting the substance B with the substance A having a polyurethane structure formed in the step (1) to obtain the urethane-modified acrylate required by the present invention.

The invention adopts the structure of the polyurethane modified acrylate formed by a specific preparation method, wherein acrylate structures are positioned at two ends of the tail end of a molecular structure of the polyurethane modified acrylate, and acrylate monomers containing hydroxyl are not adopted to react with isocyanate, so as to realize the introduction of a structural chain segment of polyurethane into acrylate resin, and acrylate containing active groups, such as carboxyl, amino and other active groups capable of reacting with hydroxyl, are not adopted to react with polyol, so as to realize the introduction of the structural chain segment of polyurethane into the acrylate resin. The coating obtained by the applicant through UV curing by using the polyurethane modified acrylic resin has high curing efficiency, the hardness and the adhesive force of the obtained coating are kept, the wear resistance and the flexibility are improved, in addition, the obtained cured paint film has smooth, colorless, transparent and full appearance, a possibly adopted terminal acrylic ester is crosslinked under UV irradiation to form a network structure, the hardness and the wear resistance of a system are improved, meanwhile, a polyurethane chain segment formed by reaction of a specific molecular weight straight chain or polypropylene glycol with a short side chain and the polyurethane chain segment containing the ring structure improves the flexibility of the system, and meanwhile, better spreading action on the surfaces of PC-ABS and tinplate is realized, so that better adhesive force is kept.

The third aspect of the invention provides a using method of the polyurethane modified acrylate UV resin, which comprises the steps of blending the resin, the reactive diluent and the initiator, stirring, coating on a PC-ABS plate and a tinplate, and curing by a UV machine to form a coating film.

In one embodiment, the reactive diluent accounts for 40-60% of the total weight of the resin, the reactive diluent and the initiator; the initiator accounts for 2-4% of the total weight; the resin is the rest; preferably, the active diluent accounts for 45-55% of the total weight; the initiator accounts for 2.5-3.5% of the total weight; the resin is the rest.

In one embodiment, the reactive diluent is selected from any one or a combination of butyl acrylate, trimethylolpropane triacrylate, tripropylene glycol diacrylate.

In another embodiment, the reactive diluent may also be an organic solvent, which is not particularly limited in the present invention, and is an organic solvent well known in the art for adjusting the viscosity of acrylate systems, such as acetone, etc.

The initiator is not particularly limited in the present invention, and is a commonly used initiator for UV curing of acrylate systems well known to those skilled in the art, such as but not limited to: azobisisobutyronitrile, dibenzoyl peroxide, dicumyl peroxide, dilauroyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, tert-butyl hydroperoxide, cumene hydroperoxide, and the like.