WO2017101742A1 - 一种速干型防腐漆及其制备方法 - Google Patents

一种速干型防腐漆及其制备方法 Download PDF

Info

Publication number
WO2017101742A1
WO2017101742A1 PCT/CN2016/109427 CN2016109427W WO2017101742A1 WO 2017101742 A1 WO2017101742 A1 WO 2017101742A1 CN 2016109427 W CN2016109427 W CN 2016109427W WO 2017101742 A1 WO2017101742 A1 WO 2017101742A1
Authority
WO
WIPO (PCT)
Prior art keywords
quick
drying
anticorrosive paint
mixture
drying anticorrosive
Prior art date
Application number
PCT/CN2016/109427
Other languages
English (en)
French (fr)
Inventor
钱建良
Original Assignee
常熟市方塔涂料化工有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 常熟市方塔涂料化工有限公司 filed Critical 常熟市方塔涂料化工有限公司
Publication of WO2017101742A1 publication Critical patent/WO2017101742A1/zh

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
    • C09D5/08—Anti-corrosive paints
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D163/00—Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C09D7/60—Additives non-macromolecular
    • C09D7/61—Additives non-macromolecular inorganic

Definitions

  • the invention relates to the technical field of preparation of anticorrosive paints, in particular to a quick-drying anticorrosive paint and a preparation method thereof.
  • the technical problem mainly solved by the invention is to provide a quick-drying anticorrosive paint and a preparation method thereof, which can solve the defects that the existing anticorrosive paint can not be quickly dried and formed into a film under certain circumstances, and is harmful to the contact person and the environment.
  • a technical solution adopted by the present invention is to provide a quick-drying anticorrosive paint comprising the following components by weight: 70-80% of matrix resin, 30-50% of filler, 20-30 of plasticizer %, auxiliary agent 8-10%, antifoaming agent 0.1-0.2%, solvent 20-30%; wherein the matrix resin is a mixture of a chlorine-containing resin and a phenolic-modified epoxy resin, the filler is zinc phosphate, a mixture of sericite, carbon black and large white powder, the plasticizer is DOP, the auxiliary is a mixture of sodium lauryl sulfate and bentonite, the antifoaming agent is an emulsified silicone oil, and the solvent is ethanol and a mixture of pentaerythritol.
  • the matrix resin is a mixture of a chlorine-containing resin and a phenolic-modified epoxy resin
  • the filler is zinc phosphate, a mixture of sericite, carbon black and large white powder
  • the plasticizer is
  • the mixing ratio of the chlorine-containing resin and the phenolic-modified epoxy resin is from 3 to 5: 4 to 7.
  • the mixing ratio of the zinc phosphate, sericite, carbon black and white powder is from 3 to 5:2 to 3: 1 to 2: 3 to 2.
  • the mass ratio of the sodium lauryl sulfate to the bentonite is from 1 to 3:2 to 5.
  • the volume ratio of the ethanol to the pentaerythritol is from 2 to 3:3 to 5.
  • another technical solution adopted by the present invention is to provide a method for preparing a quick-drying anticorrosive paint, comprising the following steps:
  • the powder of the step (1) is added to the matrix resin, and then added to the solvent, ultrasonic dispersion for 1 ⁇ 2h;
  • the stirring condition in the step (6) is: a temperature of 30 to 50 ° C, a rotation speed of 1200 r / min, and a time of 3 to 5 h.
  • the quick-drying anticorrosive paint has a degree of adhesion of 1 grade, and has good anti-corrosion performance under oily water and acidic conditions, and the drying time is less than 6 h.
  • the preparation method of the quick-drying anticorrosive paint of the invention is simple and easy to implement; the invention ensures good adhesion and environmental protection performance by the reasonable selection of the formula materials, the proportion design and the reasonable process control. Under the premise, it has excellent anti-corrosion and quick-drying properties, and has important applications in low temperature and humid special environments.
  • a quick-drying anticorrosive paint comprising the following components by weight: 70-80% of matrix resin, 30-50% of filler, 20-30% of plasticizer, 8-10% of auxiliary agent, 0.1-0.2% of antifoaming agent a solvent of 20 to 30%; wherein the matrix resin is a mixture of a chlorine-containing resin and a phenolic-modified epoxy resin, the filler being a mixture of zinc phosphate, sericite, carbon black and large white powder, the plasticizer
  • the adjuvant is a mixture of sodium lauryl sulfate and bentonite
  • the antifoaming agent being an emulsified silicone oil
  • the solvent being a mixture of ethanol and pentaerythritol.
  • a quick-drying anticorrosive paint whose weight percentage components are as follows:
  • mass ratio of 5:7 mixed chlorine resin and phenolic modified epoxy resin matrix resin 80%, by mass ratio of 5: 3: 2: 2 mixed zinc phosphate, sericite, carbon black and white powder filler 50%, plasticizer (DOP) 30%, mass ratio of 3:5 mixed sodium lauryl sulfate and bentonite additives 10% , defoamer (emulsified silicone oil) 0.2%, 3:5 by volume of ethanol and pentaerythritol solvent 30%;
  • the powder of the step (1) is added to the matrix resin, and then added to the solvent, ultrasonic dispersion for 1 ⁇ 2h;
  • step (3) adding a plasticizer to the solution prepared in the step (2), and stirring at a temperature of 30 to 50 ° C at a rotation speed of 1200 r / min for 3 to 5 hours to obtain a quick-drying anticorrosive paint.
  • the quick-drying anticorrosive paint prepared by the above method has the adhesion degree of 1 grade, and has good anti-corrosion performance under oil water and acidic conditions, and the drying time is less than 5 h.
  • a quick-drying anticorrosive paint whose weight percentage components are as follows:
  • the powder of the step (1) is added to the matrix resin, and then added to the solvent, ultrasonic dispersion for 1 ⁇ 2h;
  • step (3) adding a plasticizer to the solution prepared in the step (2), and stirring at a temperature of 30 to 50 ° C at a rotation speed of 1200 r / min for 3 to 5 hours to obtain a quick-drying anticorrosive paint.
  • the quick-drying anticorrosive paint prepared by the above method has the adhesion degree of 1 grade, and has good anti-corrosion performance under oil water and acidic conditions, and the drying time is less than 7 h.

Abstract

一种速干型防腐漆及其制备方法，所述速干型防腐漆包括如下重量百分数的成分：基体树脂70～80％、填料30～50％、增塑剂20～30％、助剂8～10％、消泡剂0.1～0.2％、溶剂20～30％。通过该配方材料的合理选择、配比设计及合理的工艺控制，使所制备的防腐漆在保持良好附着力和环保性能的前提下，具有优异的防腐、速干的特性，在低温，湿润特殊环境中具有重要应用。

Description

一种速干型防腐漆及其制备方法 Technical Field
本发明涉及防腐漆制备技术领域，特别是涉及一种速干型防腐漆及其制备方法。
 Background Art
金属材料在使用中会发生自发的腐蚀过程，世界上金属材料及其制品每年有近1/3的损失，所以防腐材料有着重要应用。而在材料的防腐过程中，由于受到环境、气候、季节的影响，导致低温、湿润环境下防腐漆不能快速干燥成膜，影响后续工序进行。而目前主要靠添加催干剂解决特定环境下防腐漆不能快速干燥成膜的问题，但是催干剂多使用有毒、挥发性有机溶剂，会对接触人员和环境造成较大危害。
 Technical Solution
本发明主要解决的技术问题是提供一种速干型防腐漆及其制备方法，能够解决现有防腐漆特定环境下不能快速干燥成膜及对接触人员和环境有危害的缺点。
为解决上述技术问题，本发明采用的一个技术方案是：提供一种速干型防腐漆，包括如下重量百分数的成分：基体树脂70～80%、填料30～50%、增塑剂20～30%、助剂8～10%、消泡剂0.1～0.2%、溶剂20～30%；其中，所述基体树脂为含氯树脂和酚醛改性环氧树脂的混合物，所述填料为磷酸锌、绢云母、碳黑和大白粉的混合物，所述增塑剂为DOP，所述助剂为十二烷基硫酸钠和膨润土的混合物，所述消泡剂为乳化硅油，所述溶剂为乙醇和季戊四醇的混合物。
在本发明一个较佳实施例中，所述含氯树脂和酚醛改性环氧树脂的混合质量比为3～5: 4～7。
在本发明一个较佳实施例中，所述磷酸锌、绢云母、碳黑和大白粉的混合质量比为3～5:2～3: 1～2:3～2。
在本发明一个较佳实施例中，所述十二烷基硫酸钠和膨润土混合质量比为1～3:2～5。
在本发明一个较佳实施例中，所述乙醇和季戊四醇混合体积比为2～3:3～5。
为解决上述技术问题，本发明采用的另一个技术方案是：提供一种速干型防腐漆的制备方法，包括如下步骤：
（1）将基体助剂和填料混合均匀，砂磨机研磨至可通过50um以下；
（2）将步骤（1）研磨的粉末加入到基体树脂中，再加入溶剂，超声分散1～2h；
（3）向步骤（2）制备的溶液中加入增塑剂，一定条件下搅拌均匀制得速干型防腐漆。
在本发明一个较佳实施例中，所述步骤（6）中的搅拌条件为：温度30～50℃，转速1200r/min，时间3～5h。
在本发明一个较佳实施例中，所述速干型防腐漆附着力1级，在油水和酸性条件下均具有良好防腐蚀性能，干燥时间小于6h。
 Advantageous Effects
本发明一种速干型防腐漆的制备方法操作简便，容易实现；本发明通过配方材料的合理选择、配比设计及合理的工艺控制，使所制备的防腐漆在保持良好附着力和环保性能的前提下，具有优异的防腐、速干的特性，在低温，湿润特殊环境中具有重要应用。
Mode for Invention
下面对本发明的较佳实施例进行详细阐述，以使本发明的优点和特征能更易于被本领域技术人员理解，从而对本发明的保护范围做出更为清楚明确的界定。
本发明实施例包括：
一种速干型防腐漆，包括如下重量百分数的成分：基体树脂70～80%、填料30～50%、增塑剂20～30%、助剂8～10%、消泡剂0.1～0.2%、溶剂20～30%；其中，所述基体树脂为含氯树脂和酚醛改性环氧树脂的混合物，所述填料为磷酸锌、绢云母、碳黑和大白粉的混合物，所述增塑剂为DOP，所述助剂为十二烷基硫酸钠和膨润土的混合物，所述消泡剂为乳化硅油，所述溶剂为乙醇和季戊四醇的混合物。
实施例1
一种速干型防腐漆，其重量百分数成分如下：
按质量比为5: 7混合的含氯树脂和酚醛改性环氧树脂的基体树脂80%，按质量比为5: 3: 2: 2混合的磷酸锌、绢云母、碳黑和大白粉的填料50%，增塑剂（DOP）30%、按质量比为3:5混合的十二烷基硫酸钠和膨润土的助剂10%、消泡剂（乳化硅油）0.2%、按体积比为3:5混合的乙醇和季戊四醇的溶剂30%；
制备方法：
（1）将基体助剂和填料混合均匀，砂磨机研磨至可通过50um以下；
（2）将步骤（1）研磨的粉末加入到基体树脂中，再加入溶剂，超声分散1～2h；
（3）向步骤（2）制备的溶液中加入增塑剂，在温度30～50℃下，以1200r/min转速，搅拌3～5h，制得速干型防腐漆。
上述方法制备的速干型防腐漆附着力1级，在油水和酸性条件下均具有良好防腐蚀性能，干燥时间小于5h。
实施例2
一种速干型防腐漆，其重量百分数成分如下：
按质量比为5: 7混合的含氯树脂和酚醛改性环氧树脂的基体树脂70%，按质量比为3:2:1:3混合的磷酸锌、绢云母、碳黑和大白粉的填料30%，增塑剂（DOP）20%、按质量比为1:2混合的十二烷基硫酸钠和膨润土的助剂8%、消泡剂（乳化硅油）0.1%、按体积比为2:3混合的乙醇和季戊四醇的溶剂20%；
制备方法：
（1）将基体助剂和填料混合均匀，砂磨机研磨至可通过50um以下；
（2）将步骤（1）研磨的粉末加入到基体树脂中，再加入溶剂，超声分散1～2h；
（3）向步骤（2）制备的溶液中加入增塑剂，在温度30～50℃下，以1200r/min转速，搅拌3～5h，制得速干型防腐漆。
上述方法制备的速干型防腐漆附着力1级，在油水和酸性条件下均具有良好防腐蚀性能，干燥时间小于7h。
以上所述仅为本发明的实施例，并非因此限制本发明的专利范围，凡是利用本发明说明书内容所作的等效结构或等效流程变换，或直接或间接运用在其他相关的技术领域，均同理包括在本发明的专利保护范围内。

Claims (8)

  1. 一种速干型防腐漆，其特征在于，包括如下重量百分数的成分：基体树脂70～80%、填料30～50%、增塑剂20～30%、助剂8～10%、消泡剂0.1～0.2%、溶剂20～30%；其中，所述基体树脂为含氯树脂和酚醛改性环氧树脂的混合物，所述填料为磷酸锌、绢云母、碳黑和大白粉的混合物，所述增塑剂为DOP，所述助剂为十二烷基硫酸钠和膨润土的混合物，所述消泡剂为乳化硅油，所述溶剂为乙醇和季戊四醇的混合物。
  2. 根据权利要求1所述的速干型防腐漆，其特征在于，所述含氯树脂和酚醛改性环氧树脂的混合质量比为3～5: 4～7。
  3. 根据权利要求1所述的速干型防腐漆，其特征在于，所述磷酸锌、绢云母、碳黑和大白粉的混合质量比为3～5:2～3: 1～2:3～2。
  4. 根据权利要求1所述的速干型防腐漆，其特征在于，所述十二烷基硫酸钠和膨润土混合质量比为1～3:2～5。
  5. 根据权利要求1所述的速干型防腐漆，其特征在于，所述乙醇和季戊四醇混合体积比为2～3:3～5。
  6. 一种如权利要求1至5之一所述的速干型防腐漆的制备方法，其特征在于，包括如下步骤：
    （1）将基体助剂和填料混合均匀，砂磨机研磨至可通过50um以下；
    （2）将步骤（1）研磨的粉末加入到基体树脂中，再加入溶剂，超声分散1～2h；
    （3）向步骤（2）制备的溶液中加入增塑剂，一定条件下搅拌均匀制得速干型防腐漆。
  7. 根据权利要求6所述的速干型防腐漆的制备方法，其特征在于，所述步骤（3）中的搅拌条件为：温度30～50℃，转速1200r/min，时间3～5h。
  8. 根据权利要求6所述的速干型防腐漆的制备方法，其特征在于，所述速干型防腐漆附着力1级，在油水和酸性条件下均具有良好防腐蚀性能，干燥时间小于6h。
PCT/CN2016/109427 2015-12-17 2016-12-12 一种速干型防腐漆及其制备方法 WO2017101742A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201510948018.9A CN105368261A (zh) 2015-12-17 2015-12-17 一种速干型防腐漆及其制备方法
CN201510948018.9 2015-12-17

Publications (1)

Publication Number Publication Date
WO2017101742A1 true WO2017101742A1 (zh) 2017-06-22

Family

ID=55370917

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2016/109427 WO2017101742A1 (zh) 2015-12-17 2016-12-12 一种速干型防腐漆及其制备方法

Country Status (2)

Country Link
CN (1) CN105368261A (zh)
WO (1) WO2017101742A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108165965A (zh) * 2017-12-27 2018-06-15 北京涌阔科技有限公司 一种镁合金防腐蚀复合膜的制备方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105368261A (zh) * 2015-12-17 2016-03-02 常熟市方塔涂料化工有限公司 一种速干型防腐漆及其制备方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000063741A (ja) * 1998-08-12 2000-02-29 Iwakiri:Kk 速乾性防錆塗料
KR20100001234A (ko) * 2008-06-26 2010-01-06 에스티엑스조선해양 주식회사 선박 케이블 트레이용 분체도료 및 이를 이용한 선박케이블 트레이 도장방법
CN102391779A (zh) * 2011-09-29 2012-03-28 资阳赛特化工有限公司 金属基材防腐涂料及其制备方法
CN104087126A (zh) * 2014-07-15 2014-10-08 南京航空航天大学 海洋防腐涂料
CN105368261A (zh) * 2015-12-17 2016-03-02 常熟市方塔涂料化工有限公司 一种速干型防腐漆及其制备方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN100343352C (zh) * 2004-07-22 2007-10-17 中国科学院兰州化学物理研究所 水汽管道内防粘防腐涂料
CN103409037A (zh) * 2013-08-06 2013-11-27 信和新材料股份有限公司 一种溶剂型低温快速固化双组份环氧涂料及其制备方法
CN103483984A (zh) * 2013-10-10 2014-01-01 常熟市方塔涂料化工有限公司 一种环保型防腐涂料
CN105017939A (zh) * 2015-06-30 2015-11-04 湖州大周高分子材料有限公司 一种环保型防腐涂料

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000063741A (ja) * 1998-08-12 2000-02-29 Iwakiri:Kk 速乾性防錆塗料
KR20100001234A (ko) * 2008-06-26 2010-01-06 에스티엑스조선해양 주식회사 선박 케이블 트레이용 분체도료 및 이를 이용한 선박케이블 트레이 도장방법
CN102391779A (zh) * 2011-09-29 2012-03-28 资阳赛特化工有限公司 金属基材防腐涂料及其制备方法
CN104087126A (zh) * 2014-07-15 2014-10-08 南京航空航天大学 海洋防腐涂料
CN105368261A (zh) * 2015-12-17 2016-03-02 常熟市方塔涂料化工有限公司 一种速干型防腐漆及其制备方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
JING YINLI ET AL.: "Development of fast drying one component chlorine-containing anticorrosive coatings", SHANGHAI COATINGS, 30 November 2014 (2014-11-30), pages 7 - 10, ISSN: 1009-1696 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108165965A (zh) * 2017-12-27 2018-06-15 北京涌阔科技有限公司 一种镁合金防腐蚀复合膜的制备方法
CN108165965B (zh) * 2017-12-27 2019-11-26 温岭市合丰鞋材有限公司 一种镁合金防腐蚀复合膜的制备方法

Also Published As

Publication number Publication date
CN105368261A (zh) 2016-03-02

Similar Documents

Publication Publication Date Title
CN107163815B (zh) 防腐蚀、防火型钢结构专用涂料及其制备方法
CN105542644B (zh) 一种纳米二氧化硅改性水性聚氨酯防水涂料及其制备方法
CN106189677B (zh) 一种低表面处理环氧涂料及其制造方法
CN102746766A (zh) 一种水性防腐涂料及其制备方法
CN103642376A (zh) 一种防水涂料
CN104559336A (zh) 一种改性硅溶胶及其制备方法
CN109575774B (zh) 一种稀土多彩抗腐蚀水性涂料及其制备方法
CN105385305B (zh) 富含微胶囊结构改性锌粉的水性环氧富锌涂料及其制备
CN108300200A (zh) 一种水性uv涂料及其制备方法
CN103305129A (zh) 改性无机硅酸锂粘结剂及其制备方法和用途
CN104371524A (zh) 一种隔热防火水性涂料及其制备方法
WO2021109731A1 (zh) 一种自乳化环氧树脂乳液及其制备方法和应用
CN107502189A (zh) 一种新型水性沥青涂料组合物及其制备方法
WO2017101742A1 (zh) 一种速干型防腐漆及其制备方法
CN104119708A (zh) 一种无机富锌防腐涂料
CN111073359A (zh) 一种无机涂料及其制备方法
CN107815240A (zh) 防腐家具涂料及生产方法
CN111410556B (zh) 一种高性能混凝土表面防护剂及其制备方法
CN107043560A (zh) 一种无机干粉防腐蚀涂料及其应用
CN108531018A (zh) 一种环保型建筑防水涂料及其制备方法
CN113913073B (zh) 一种耐候防水阻燃一体化涂料及其制备方法
CN105110697A (zh) 一种渗透反应型防水防腐添加剂以及含有该添加剂的砂浆组合物
CN108610891A (zh) 机房电缆用环保耐高温抗静电绝缘漆组合物
CN110041787A (zh) 一种环保水性绝缘漆及其制备方法
CN110054454A (zh) 一种水性轮胎粉聚合物水泥基防水浆料及其制备方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16874799

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 16874799

Country of ref document: EP

Kind code of ref document: A1