阅读说明：本技术 一种汽车复合材料粘接用底涂剂及其制备方法 (Primer for bonding automobile composite material and preparation method thereof ) 是由 赵景左 唐礼道 韩胜利 王翠花 赵勇刚 章锋 于 2019-09-04 设计创作，主要内容包括：本发明公开了一种汽车复合材料粘接用底涂剂及其制备方法,属于聚氨酯胶粘接底涂剂技术领域。该底涂剂包括10～30重量份异氰酸酯基含量为6wt％～8wt％的硅烷偶联剂、5～15重量份异氰酸酯基含量为2wt％～5wt％的树脂、5～10重量份异氰酸酯基含量为6wt％～9wt％的聚烯烃、0～0.5重量份含氯量为20wt％～45wt％的氯化聚烯烃、5～10重量份粉料助剂、0.5～1重量份催化剂和10～50重量份溶剂,该底涂剂表干时间快、对汽车复合材料附着力高,并具有较好的耐高温高湿性能,配合单组份聚氨酯粘接胶使用,可节约生产线场地空间,方便施胶,提高汽车制造的生产效率,解决了现有单组份聚氨酯胶底涂剂无法在汽车复合材料上应用,特别是不耐高温高湿的问题。(The invention discloses a primer for bonding automobile composite materials and a preparation method thereof, belonging to the technical field of polyurethane adhesive primers. The primer comprises 10-30 parts by weight of silane coupling agent with 6-8 wt% of isocyanate group, 5-15 parts by weight of resin with 2-5 wt% of isocyanate group, 5-10 parts by weight of polyolefin with 6-9 wt% of isocyanate group, 0-0.5 part by weight of chlorinated polyolefin with 20-45 wt% of chlorine content, 5-10 parts by weight of powder auxiliary agent, 0.5-1 part by weight of catalyst and 10-50 parts by weight of solvent, the primer has the advantages of quick surface drying time, high adhesive force to automobile composite materials, better high temperature and high humidity resistance, and matching with single-component polyurethane adhesive for use, the primer can save the production line site space, facilitate the sizing, improve the production efficiency of automobile manufacturing, and solve the problems that the existing single-component polyurethane adhesive primer cannot be applied to automobile composite materials, and particularly cannot resist high temperature and high humidity.)

1. The primer for bonding the automobile composite material is characterized by being prepared from the following raw materials:

the content of isocyanate groups in the silane coupling agent containing isocyanate groups is 6 to 8 weight percent;

the content of isocyanate groups in the resin containing the isocyanate groups is 2 to 5 weight percent, and the resin containing the isocyanate groups is formed by condensing polyisocyanate and dimer acid modified polyester polyol or dimer urea modified polyester polyol;

the content of isocyanate groups in the polyolefin containing isocyanate groups is 6 to 9 weight percent;

the chlorine content of the chlorinated polyolefin is 20 wt% -45 wt%;

the polarity of the solvent A is not higher than that of acetone.

2. The primer for bonding automobile composite materials according to claim 1, characterized in that: the silane coupling agent containing isocyanate groups is a gamma-isocyanate silane coupling agent.

3. The primer for bonding automobile composite materials according to claim 2, characterized in that: the gamma-isocyanate silane coupling agent is gamma-isocyanate propyl trimethoxy silane or gamma-isocyanate propyl triethoxy silane.

4. The primer for bonding automobile composite materials according to claim 1, characterized in that: the catalyst is a polyurethane catalyst.

5. The primer for bonding automobile composite materials according to claim 1, characterized in that: chlorinated polypropylene with the room-temperature viscosity of 20-100 mPa.S of the chlorinated polyolefin; the solvent A is one or more of acetone, butanone, cyclohexanone, tetrahydrofuran, ethyl formate, ethyl acetate, propyl acetate, butyl acetate and toluene; the catalyst is one or more of triethylamine, triethylene diamine, stannous octoate and dibutyltin dilaurate.

6. The primer for bonding automobile composite materials according to claim 1, characterized in that: the silane coupling agent containing the isocyanate group is prepared by the following preparation method: mixing polyisocyanate C and silane coupling agent B, heating to 75-78 ℃, carrying out heat preservation reaction, and obtaining the silane coupling agent containing isocyanate groups with the isocyanate group content of 6-8 wt% after the reaction is completed; the molar ratio of the isocyanate group in the polyisocyanate C to the active group in the silane coupling agent B is 1.2-1.6: 1; the active group in the silane coupling agent B is sulfydryl or amino, and the polyisocyanate C is one or more of diphenylmethane diisocyanate, toluene diisocyanate, l, 6-hexamethylene diisocyanate biuret, l, 6-hexamethylene diisocyanate trimer and isophorone diisocyanate trimer.

7. The primer for bonding automobile composite materials according to claim 1, characterized in that: the isocyanate group-containing resin is obtained by the following preparation method: mixing polyisocyanate D and dimer acid modified polyester polyol or dimer urea modified polyester polyol, heating to 75-78 ℃, carrying out heat preservation reaction, and obtaining resin containing isocyanate groups with the isocyanate group content of 2-5 wt% after complete reaction; the polyisocyanate D is diphenylmethane diisocyanate or toluene diisocyanate; the dimer acid modified polyester polyol or the dimer urea modified polyester polyol has a bifunctional degree and a molecular weight of 1000-6000; the molar ratio of isocyanate groups in the polyisocyanate D to hydroxyl groups in the dimer acid-modified polyester polyol or the diperea-modified polyester polyol is 1.0-1.4: 1.

8. The primer for bonding automobile composite materials according to claim 1, characterized in that: the polyolefin containing isocyanate groups is prepared by the following method: mixing polyisocyanate E and hydroxyl-terminated polyolefin, heating to 75-78 ℃, carrying out heat preservation reaction, and obtaining polyolefin containing isocyanate groups with the isocyanate group content of 6-9 wt% after the reaction is completed; the polyisocyanate E is MDI-50 or polymeric MDI; the molar ratio of isocyanate groups in the polyisocyanate E to hydroxyl groups in the hydroxyl-terminated polyolefin is 5-7: 1; the hydroxyl-terminated polyolefin has a functionality of 1.8-2.4 and a molecular weight of 2000-5000.

9. The primer for bonding automobile composite materials according to claim 1, characterized in that: the hydroxyl terminated polyolefin is hydroxyl terminated linear polybutadiene.

10. A method for preparing the primer for bonding the automobile composite material, which is characterized by comprising the following steps of:

under the protection of nitrogen, uniformly dispersing 10-30 parts by weight of silane coupling agent containing isocyanate groups, 5-15 parts by weight of resin containing isocyanate groups, 5-10 parts by weight of polyolefin containing isocyanate groups, 0-0.5 part by weight of chlorinated polyolefin, 5-10 parts by weight of powder auxiliary agent and 0.5-1 part by weight of catalyst in 10-50 parts by weight of solvent A to obtain the primer for bonding the automobile composite material.

Technical Field

The invention belongs to the technical field of polyurethane adhesive primer, and relates to a primer for bonding an automobile composite material and a preparation method thereof.

Background

Generally, doors, roofs, seat parts, and peripheral structural members of automobiles use engineering plastics and composite materials, which are fixed to a vehicle body by means of adhesion. Most of the prior art adopts two-component structural adhesive after flame treatment or plasma treatment of composite materials, such as Doudar 6023 or Hubei Hui Haitian New materials Co., Ltd HT8667 for adhesion, and the two-component adhesive has complex adhesive applying equipment during adhesive applying and is often limited by the field of a manufacturing assembly line.

The single-component polyurethane structural adhesive gluing equipment is simple and can solve the problems. However, the single-component polyurethane adhesive is directly applied to the surface of the composite material treated by flame or plasma, the bonding effect is poor after curing, peeling and debonding are realized, even if the single-component polyurethane adhesive is matched with the primer for glass surface or paint surface sizing, the bonding property of normal-temperature curing is improved, 100% cohesive failure cannot be achieved, and even the primer and the surface of the composite material substrate can be directly debonded after damp-heat aging.

At present, a mature polyurethane sealant primer is provided, for example, in the technical schemes disclosed in chinese patent applications CN102140304A and CN103113819A, although the surface drying time is fast and the primer has good adhesion with a polyurethane sealant adhesive, the primer has a risk of debonding the primer when being applied to substrates such as automobile glass and aluminum plates, and the like, and applied to automobile composite materials, especially under high temperature and high humidity conditions.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a primer for bonding an automobile composite material, which aims to solve the problem of poor humidity resistance and heat resistance of the existing primer.

The technical scheme provided by the invention is as follows:

the primer for bonding the automobile composite material is prepared from the following raw materials:

the content of isocyanate group in the silane coupling agent containing isocyanate group is 6-8 wt%;

the content of isocyanate group in the resin containing isocyanate group is 2-5 wt%, and the resin containing isocyanate group is formed by condensing polyisocyanate and polyester polyol modified by dimer acid or polyester polyol modified by biuret;

the content of isocyanate group in the polyolefin containing isocyanate group is 6-9 wt%, and the polyolefin containing isocyanate group is formed by condensing polyisocyanate and hydroxyl-terminated polyolefin;

the chlorine content of the chlorinated polyolefin is 20 to 45 weight percent;

the polarity of the solvent A is not higher than that of acetone.

According to the technical scheme, the silane coupling agent containing the isocyanate group is a gamma-isocyanate silane coupling agent.

According to the technical scheme, the gamma-isocyanate silane coupling agent is gamma-isocyanate propyl triethoxysilane or gamma-isocyanate propyl trimethoxysilane, such as Mitigo A-Link25 or Mitigo A-Link35 produced by the American Mitigo advanced materials group.

According to the technical scheme, the chlorinated polyolefin is chlorinated polypropylene with the chlorine content of 20-45 wt% and the room-temperature viscosity of 20-100 mPa.S, such as one or more of Superchlorine 822, 892L and 814HS produced by Japan paper making chemical company; among them, 814HS is preferable.

According to the technical scheme, the catalyst is a polyurethane catalyst, and one or more of triethylamine, triethylene diamine, stannous octoate and dibutyltin dilaurate are specifically selected; among them, triethylene diamine or stannous octoate is preferable.

According to the technical scheme, the solvent A is one or more of acetone, butanone, cyclohexanone, tetrahydrofuran, ethyl formate, ethyl acetate, propyl acetate, butyl acetate and toluene.

According to the technical scheme, the silane coupling agent containing isocyanate groups is prepared by the following preparation method: mixing polyisocyanate C and silane coupling agent B, heating to 75-78 ℃, carrying out heat preservation reaction, and obtaining the silane coupling agent containing isocyanate groups with the isocyanate group content of 6-8 wt% after the reaction is completed; the molar ratio of the isocyanate group in the polyisocyanate C to the active group in the silane coupling agent B is 1.2-1.6: 1; the active group in the silane coupling agent B is sulfydryl or amino, and the polyisocyanate C is one or more of diphenylmethane diisocyanate (MDI), Toluene Diisocyanate (TDI), l, 6-hexamethylene diisocyanate biuret (HDI biuret), l, 6-hexamethylene diisocyanate trimer (HDI trimer) and isophorone diisocyanate trimer (IPDI trimer).

Based on the technical scheme, the silane coupling agent B is A-1100, A-1110 or A-189 produced by advanced materials group of Michigan, USA, wherein the A-1110 has the best performance.

According to the technical scheme, the resin containing isocyanate groups is prepared by the following preparation method: mixing polyisocyanate D and dimer acid modified polyester polyol or dimer urea modified polyester polyol, heating to 75-78 ℃, carrying out heat preservation reaction, and obtaining resin containing isocyanate groups with the isocyanate group content of 2-5 wt% after complete reaction; the polyisocyanate D is diphenylmethane diisocyanate or toluene diisocyanate; the dimer acid modified polyester polyol or the dimer urea modified polyester polyol has a bifunctional degree and a molecular weight of 1000-6000; the molar ratio of isocyanate groups in the polyisocyanate D to hydroxyl groups in the dimer acid-modified polyester polyol or the polyurea-modified polyester polyol is 1.0-1.4: 1, and the dimer acid-modified polyester polyol or the polyurea-modified polyester polyol is preferably DA20, DA21, D21H and DA2110 produced by Shanghai Jingtian new materials, and is most preferably DA 21.

According to the technical scheme, the polyolefin containing isocyanate groups is prepared by the following method: mixing polyisocyanate E and hydroxyl-terminated polyolefin, heating to 75-78 ℃, carrying out heat preservation reaction, and obtaining polyolefin containing isocyanate groups with the isocyanate group content of 6-9 wt% after the reaction is completed; the molar ratio of isocyanate groups in the polyisocyanate E to hydroxyl groups in the hydroxyl-terminated polyolefin is 5-7: 1; the hydroxyl-terminated polyolefin has a functionality of 1.8 to 2.4 and a molecular weight of 2000 to 5000. The polyisocyanate E is MDI-50 or a polymeric MDI, such as PM200, with MDI-50 being preferred.

Preferably, the hydroxyl terminated polyolefin is hydroxyl terminated linear polybutadiene having a molecular weight of 2000 to 5000 and a hydroxyl functionality of 1.8 to 2.4, such as Poly bd R45V and KrasolLBH-3000 manufactured by Kreivri.

A method for preparing the primer for bonding the automobile composite material comprises the following steps:

under the protection of nitrogen, uniformly dispersing 10-30 parts by weight of silane coupling agent containing isocyanate groups, 5-15 parts by weight of resin containing isocyanate groups, 5-10 parts by weight of polyolefin containing isocyanate groups, 0-0.5 part by weight of chlorinated polyolefin, 5-10 parts by weight of powder auxiliary agent and 0.5-1 part by weight of catalyst in 10-50 parts by weight of solvent A to obtain the primer for bonding the automobile composite material. The specific dispersion mode is high-speed stirring, ball milling or grinding in a sand mill, and the time is 30-60 min.

The primer prepared by the invention comprises the following components in percentage by weight: the siloxane end of the silane coupling agent containing the isocyanate group can act with the interface of the base material of the automobile composite material to generate good adhesive force and has excellent damp-heat aging resistance; the isocyanate group-containing resin enables the primer to have good toughness after forming a film, the primer film is not cracked under the action of external force, and the resin has good hydrolysis resistance and stable performance in a high-temperature and high-humidity environment; the polyolefin containing isocyanate group has a polyolefin structure chain segment which can also enable a primer film to have certain toughness, and the polyolefin and the surface of the automobile composite material have lower polarity, and a contact interface between the polyolefin and the surface of the automobile composite material has higher adhesive force, and the polyolefin containing 40 wt% of chlorine is matched, so that the chain segment proportion of the polyolefin is increased, and the polyolefin has further adhesive force with the base surface of the automobile composite material.

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

(1) the primer provided by the invention is a reactive primer, and has a good bonding effect with a single-component polyurethane adhesive and a composite material substrate, so that a good transition layer is formed, and the problem of debonding caused by the mismatch of the interface polarities of the polyurethane adhesive and the primer is avoided.

(2) The primer provided by the invention is diluted by an organic solvent, the solid content of the primer can be controlled to be 20-70 wt%, the surface drying time is less than 1min, and the sizing process of the single-component polyurethane adhesive can be carried out after 2-5 min, so that the production efficiency of automobile manufacturing can be greatly improved.

(3) The primer provided by the invention has good bonding performance with the base materials such as polypropylene materials (PP), long glass fiber reinforced PP materials (LGFPP), polycarbonate materials (PC), acrylonitrile-butadiene-styrene plastics (ABS), Sheet Molding Compounds (SMC) and the like which are commonly used in automobiles, and has good high-temperature and high-humidity resistance after bonding.

Detailed Description

The technical solution of the present invention will be described in detail below with reference to specific examples.

The gamma-isocyanate propyl triethoxy silane used in the invention is Mitigo A-Link25 produced by the American Mitigo high and new materials group, the adopted gamma-isocyanate propyl trimethoxy silane has the product number of Mitigo A-Link35, the used silane coupling agent is A-1100, A-1110 or A-189 produced by the American Mitigo high and new materials group, the used dimer acid modified polyester polyol or the dimer urea modified polyester polyol has the product numbers of DA20, DA21 and D21H produced by Shanghai Jingri new materials company, DA2110, the chlorinated polypropylene used is Superchlor 822, 892L, 814HS available from Japan paper chemistry, the polyisocyanate E used for the production of the polyolefins containing isocyanate groups is MDI-50, PM200 available, and the hydroxyl-terminated linear polybutadiene used is Poly bd R45V or KrasolLBH-3000 available from Kreviley.