[go: up one dir, main page]

WO2009130334A1 - Utilisation d’hydrocarbures comme additifs pour réduire le dégagement de poussière de produits chimiques de construction - Google Patents

Utilisation d’hydrocarbures comme additifs pour réduire le dégagement de poussière de produits chimiques de construction Download PDF

Info

Publication number
WO2009130334A1
WO2009130334A1 PCT/EP2009/055892 EP2009055892W WO2009130334A1 WO 2009130334 A1 WO2009130334 A1 WO 2009130334A1 EP 2009055892 W EP2009055892 W EP 2009055892W WO 2009130334 A1 WO2009130334 A1 WO 2009130334A1
Authority
WO
WIPO (PCT)
Prior art keywords
hydrocarbons
construction
use according
products
dusting
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/EP2009/055892
Other languages
German (de)
English (en)
Inventor
Markus Streicher
Klaus Hoetzl
Werner Stohr
Volker Schwarz
Alexander Ehle
Silvia DÜRNDORFER
Kornelia Kratzer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Construction Research and Technology GmbH
Original Assignee
Construction Research and Technology GmbH
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 Construction Research and Technology GmbH filed Critical Construction Research and Technology GmbH
Publication of WO2009130334A1 publication Critical patent/WO2009130334A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B24/00Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/02Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2103/00Function or property of ingredients for mortars, concrete or artificial stone
    • C04B2103/0068Ingredients with a function or property not provided for elsewhere in C04B2103/00
    • C04B2103/0075Anti-dusting agents
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00474Uses not provided for elsewhere in C04B2111/00
    • C04B2111/00663Uses not provided for elsewhere in C04B2111/00 as filling material for cavities or the like
    • C04B2111/00672Pointing or jointing materials
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/70Grouts, e.g. injection mixtures for cables for prestressed concrete
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/72Repairing or restoring existing buildings or building materials

Definitions

  • the present invention is the use of hydrocarbons or hydrocarbon mixtures as additives for reducing the dusting of dry, chemical construction products and a method for producing such products.
  • hydraulically binding or cement-based materials eg tile adhesives, joint fillers, fillers, sealing slurries
  • dust reducing agents which are added to the mixing water of cement in order to reduce the dust during the application of shotcrete or sprayed mortar.
  • polyethylene glycols or ethylene oxide / propylene oxide block copolymers are used as dust binders or additives for reducing dust formation.
  • such additives often have a negative effect on the processing behavior, since they lead in particular to a setting delay or pronounced hygroscopicity of the construction-chemical products.
  • hydrophobic additives which also include ethylene oxide / propylene oxide block copolymers, wetting difficulties arise, above all, in the case of pulverulent construction-chemical products.
  • WO 2006/084588 A1 discloses the use of aliphatic hydrocarbons and hydrocarbon mixtures as additives for reducing the dusting of dry and especially pulverulent construction-chemical products, such as tile adhesives, joint fillers, fillers, sealing slurries, etc.
  • hydrocarbons are described which are liquid under normal conditions
  • aliphatic hydrocarbons in particular in linear or branched, saturated or unsaturated form, with boiling points of 100 to 400 0 C are particularly mentioned.
  • hydrocarbons with more than 10 carbon atoms should be particularly well suited.
  • Particularly advantageous hydrocarbons in the present context are those which have a kinematic viscosity at 20 ° C.
  • the utility model DE 20 2006 016 797 111 relates to a low-dust dry mortar which contains at least one dust-reducing component in an amount of from 0.01 to 10% by weight, based on the total dry mixture.
  • the dust-reducing component is selected here from the series of monoalcohols, such as. 3-methoxybutanol, benzyl alcohol, 1,2-propanediol, hexanol, diacetone alcohol, ethyl diglycol, isopropanol, 2-ethylhexanol and / or alkanediols such as 2-methylpentane-2,4-diol, neopentylglycol and n-butane. 2,5-diol.
  • glycols polyethylene glycols, fatty alcohols and polyphenyl alcohols are also suitable. Particular mention is made of aliphatic ethers, cellulose ethers, alkoxylates and methyl / ethyl fatty acid ethers.
  • the present invention therefore an object of the invention to provide an additive with which the dusting of dry, construction chemical products can be significantly reduced.
  • Such additives should be characterized by a simple form of application with high effectiveness. In addition, they should not tend to form lumps during use and should not adversely affect the final properties of the products. Furthermore, the sustained high effectiveness of the additives over a longer period was desirable.
  • This object has been achieved by the use of hydrocarbons or hydrocarbon mixtures having a kinematic viscosity at 20 ° C. in the range from 0.1 to 25 mm 2 / s and / or of hydrocarbons or hydrocarbon mixtures having a kinematic viscosity at 40 ° C. in the range from 1 , 0 to 7 mm 2 / s.
  • the specified kinematic viscosities are determined according to ISO 3014 and / or DIN 51 562 / T1.
  • hydrocarbons which have a kinematic viscosity in the range from 5.0 to 20 mm 2 / s at 20 ° C. have proved to be particularly advantageous.
  • the following viscosities are especially suitable: 0.2, 0.4, 0.5, 0.6, 0.8, 1, 0, 2.0, 3.0, 4.0, 5.0 , 6.0, 7.0, 8.0, 9.0, 10.0, 11, 0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18 , 0, 19.0, 20.0, 21, 0, 22.0, 23.0 and 24.0 mm 2 / s.
  • the following viscosities are suitable: 1, 2, 1, 4, 1, 5, 1, 6, 1, 8, 2.0, 2.5, 3.0, 3.5, 4.0, 4 , 5, 5.0, 5.5, 6.0, 6.5 mm 2 / s.
  • cyclic hydrocarbons or mixtures thereof and in particular those containing 3 to 70 and particularly preferably 5 to 30 carbon atoms are particularly suitable.
  • suitable hydrocarbons are not subject to any particular restriction.
  • hydrocarbons or hydrocarbon mixtures which have a weight-average molecular mass of from 100 to 500 g / mol, in particular from 130 to 380 g / mol and particularly preferably from 150 to 300 g / mol, have basically proven suitable for the purposes of the present invention.
  • dust reducing agents for the purposes of the present invention, dust reducing agents, dust reducing additives or dewatering additives whose hydrocarbon representatives are selected from the series of hydrogenated butene tetramers, iso or n-paraffinic hydrocarbons and aliphatic and cyclic hydrocarbons are used to reduce dusting.
  • Isoalkanes having 9-12 carbon atoms are particularly suitable.
  • the hydrocarbon representatives used in each case are used in liquid form.
  • the advantage of this variant can be seen in the fact that liquid application forms can be better applied to the dedusting, chemical construction products and that the order takes place more homogeneously compared to solid variants.
  • smaller quantities are needed in the case of liquid hydrocarbons.
  • the adhesion or the initial adhesion of liquid additives compared to solid variants are improved.
  • the term "liquid” naturally correlates with the Viscosity essential to the invention at 20 0 C and 40 0 C, wherein predominantly the thin liquid range is meant.
  • the dry, chemical construction products which are dusted off by the additive according to the invention should, in the context of the present invention, preferably be in powder form and / or have pulverulent components, the average particle size in the respective construction chemical products preferably ranging from 0.1 to 5 mm should. It has proved to be particularly advantageous if the construction-chemical products have a particle size fraction of 2 to 10% ⁇ 68 ⁇ m and 10 to 30% ⁇ 200 ⁇ m. Particularly in the case of very finely divided variants, the dedusting potential of the hydrocarbons used according to the invention is particularly evident.
  • any desired dry, chemical construction products can be significantly dedusted with the hydrocarbons used according to the invention.
  • the use according to the invention has proven to be particularly advantageous when the construction chemical products are hydraulically setting or cement-based compositions and, in particular, tile adhesives, joint fillers, fillers, sealing slurries, repair mortars, leveling mortars, reinforcing adhesives, adhesives for thermal insulation composite systems (ETICS), mineral plasters, fine putty, screed systems, thick-bed mortar, surface protection systems and pigment preparations.
  • EICS thermal insulation composite systems
  • mineral plasters fine putty, screed systems
  • thick-bed mortar surface protection systems and pigment preparations.
  • Representative of the hydraulically setting cement-based or gypsum-based compositions should be mentioned in particular in which finely ground mineral substances harden under stone uptake in air or under water stone-like and are water resistant after curing.
  • redispersible polymer powders or tile adhesives which are the construction-chemical products or which are present as their pulverulent constituents.
  • the abovementioned redispersible polymer powders are preferably composed of at least one member of the series vinyl acetate, styrene, butadiene, ethylene, versatic acid vinyl ester, urea-formaldehyde condensation products and melamine-formaldehyde condensation products.
  • hydrocarbons or hydrocarbon mixtures to the dry, chemical product in an amount of 0.1 to 1, 5 wt .-%, preferably from 0.3 to 1, 2 wt .-% and particularly preferably from 0.5 to 1, 0 wt .-% add.
  • finely divided particles particles additionally contain at least one member of the series binders, fillers, aggregates, additives, organic or inorganic fibers and pigments.
  • the present invention also includes a method for producing dry and in particular pulverulent construction chemical products with a reduced dusting and dusting behavior.
  • this process is characterized in that the construction-chemical products are brought into contact with at least one hydrocarbon or hydrocarbon mixture as dedusting additive, which should be effected in particular by spraying.
  • the hydrocarbons or hydrocarbon mixtures used in this case have the properties already mentioned, in particular, the kinematic viscosity at 20 0 C and / or 40 0 C is mentioned.
  • the present invention also encompasses dry and in particular pulverulent, construction-chemical products which have reduced dusting and dusting behavior and which can be produced by the process just described, namely by bringing into contact and in particular by spraying.
  • the present invention comprises a construction chemical product having a reduced dusting and dusting behavior.
  • This product is in turn advantageously to hydraulically setting and / or cement or gypsum-based compounds or binders such.
  • the additives used in the context of the use according to the invention can of course also be supported by all other suitable additives in their dust-reducing or dedusting action. Even if the proposed hydrocarbons with defined viscosity in the predominant applications are completely sufficient to reduce or completely prevent the dustiness of dry, chemical construction products, it may well be useful in special cases to support the beneficial effect of these additives by other additives , which in turn also have a reducing effect on the dusting behavior.
  • additives are provided with the proposed hydrocarbons or hydrocarbon mixtures with defined viscosity, with which dry, chemical construction products can be dedusted in a simple and economical manner homogeneous and stable, so that in particular from the viewpoints of occupational safety, especially during decanting and processing a clear progress is noted.
  • Dispersion powder (Elotex AP 200) 3.0% by weight
  • Hardening accelerator (calcium formate) 0.5% by weight
  • Dispersion powder (Elotex AP 200) 4.0% by weight
  • Hardening accelerator (calcium formate) 0.5% by weight
  • Dispersion powder (Vinnapas 7031 H) 1, 0% by weight
  • Hardening accelerator (calcium formate) 0.5% by weight
  • Dispersion powder (Vinnapas 4010 L) 1, 0% by weight
  • Hardening accelerator (calcium formate) 0.5% by weight Flexible sealing slurries Portland cement CEM I 13.5% by weight Quartz sand 0.01-0.2 mm 55.5% by weight Limestone powder ⁇ 0.1 mm 5.5% by weight Dispersion powder (Vinnapas 5044 N) 25.0 % By weight hardening accelerator (calcium formate) 0.5% by weight
  • BASF GK 1778 hydrogenated butene tetramer, mp 129 ° C., boiling range> 280 ° C.
  • Cobersol H 190 alipat. + predominantly cyclic hydrocarbon fraction
  • Cobersol C120P aliphatic. + predominantly cyclic hydrocarbon fraction
  • the respective dispersion powder was placed in a mixing vessel.
  • the dedusting additive according to the invention was applied to the individual component by means of a pressure sprayer ("flower syringe") in the stated quantitative ratio and mixed homogeneously.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Sealing Material Composition (AREA)
  • Road Paving Structures (AREA)
  • Fire-Extinguishing Compositions (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)
  • Soil Conditioners And Soil-Stabilizing Materials (AREA)

Abstract

La présente invention concerne l'utilisation d'hydrocarbures ou mélanges d'hydrocarbures ayant une viscosité cinématique à 20°C de l'ordre de 0,1 à 25 mm²/s et/ou à 40°C de l'ordre de 1,0 à 7 mm²/s comme additifs pour réduire le dégagement de poussière de produits chimiques secs de construction et en particulier de pâtes à prise hydraulique ou à base de ciment ou de plâtre telles que des colles de carrelage, des pâtes de jointoiement, des mastics et des enduits d'étanchéité. Les additifs de dépoussiérage proposés ont un effet de dépoussiérage stable de longue durée et les propriétés de transformation et d'application des produits chimiques de construction traités ne sont soumises à aucune limitation.
PCT/EP2009/055892 2008-04-25 2009-05-15 Utilisation d’hydrocarbures comme additifs pour réduire le dégagement de poussière de produits chimiques de construction Ceased WO2009130334A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102008020737A DE102008020737A1 (de) 2008-04-25 2008-04-25 Verwendung von Kohlenwasserstoffen als Additive zur Verminderung des Staubens bauchemischer Produkte
DE102008020737.3 2008-04-25

Publications (1)

Publication Number Publication Date
WO2009130334A1 true WO2009130334A1 (fr) 2009-10-29

Family

ID=40935106

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2009/055892 Ceased WO2009130334A1 (fr) 2008-04-25 2009-05-15 Utilisation d’hydrocarbures comme additifs pour réduire le dégagement de poussière de produits chimiques de construction

Country Status (5)

Country Link
AR (1) AR071418A1 (fr)
CL (1) CL2009000968A1 (fr)
DE (1) DE102008020737A1 (fr)
PE (1) PE20100124A1 (fr)
WO (1) WO2009130334A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112551924A (zh) * 2021-01-22 2021-03-26 肖水 一种环保型干粉水泥制备方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3935025B1 (fr) 2019-03-07 2023-05-10 Sika Technology AG Composition de revêtement de sol hybride à base de ciment

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5447984A (en) * 1994-03-28 1995-09-05 Takemoto Yushi Kabushiki Kaisha Curable polymer mortar or concrete compositions
WO1998023705A1 (fr) * 1996-11-26 1998-06-04 S.A. Lhoist Recherche Et Developpement Compositions de traitement de sols, leur procede de preparation et leur utilisation
WO2000034200A1 (fr) * 1998-12-10 2000-06-15 3M Innovative Properties Company Compose bouche-fentes quasi exempt de poussiere
WO2003025091A2 (fr) * 2001-09-21 2003-03-27 Vlastimil Nevrkla Masse pulverisee modifiee pour le traitement des sols et des materiaux de construction en vrac
WO2006084588A2 (fr) * 2005-02-09 2006-08-17 Henkel Kommanditgesellschaft Auf Aktien Utilisation d'hydrocarbures et de melanges d'hydrocarbures aliphatiques dans des produits chimiques pulverulents pour la construction
DE202006016797U1 (de) * 2006-11-03 2006-12-28 Pci Augsburg Gmbh Staubarmer Trockenmörtel

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2739375B2 (de) * 1977-09-01 1980-06-04 Ekoperl Gmbh, 4600 Dortmund Verfahren zur Bindung von Staubanteilen in expandiertem Perlite
US4780143A (en) 1987-04-24 1988-10-25 Betz Laboratories, Inc. Methods for suppressing cement clinker dust emissions

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5447984A (en) * 1994-03-28 1995-09-05 Takemoto Yushi Kabushiki Kaisha Curable polymer mortar or concrete compositions
WO1998023705A1 (fr) * 1996-11-26 1998-06-04 S.A. Lhoist Recherche Et Developpement Compositions de traitement de sols, leur procede de preparation et leur utilisation
WO2000034200A1 (fr) * 1998-12-10 2000-06-15 3M Innovative Properties Company Compose bouche-fentes quasi exempt de poussiere
WO2003025091A2 (fr) * 2001-09-21 2003-03-27 Vlastimil Nevrkla Masse pulverisee modifiee pour le traitement des sols et des materiaux de construction en vrac
WO2006084588A2 (fr) * 2005-02-09 2006-08-17 Henkel Kommanditgesellschaft Auf Aktien Utilisation d'hydrocarbures et de melanges d'hydrocarbures aliphatiques dans des produits chimiques pulverulents pour la construction
DE202006016797U1 (de) * 2006-11-03 2006-12-28 Pci Augsburg Gmbh Staubarmer Trockenmörtel

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112551924A (zh) * 2021-01-22 2021-03-26 肖水 一种环保型干粉水泥制备方法

Also Published As

Publication number Publication date
AR071418A1 (es) 2010-06-16
PE20100124A1 (es) 2010-03-03
DE102008020737A1 (de) 2009-10-29
CL2009000968A1 (es) 2009-07-24

Similar Documents

Publication Publication Date Title
EP3664980B1 (fr) Procédé d'impression en 3d de compositions de liant minérales
EP2419388B1 (fr) Composition pulvérulente de matériau de construction dépoussiérée
EP3600811A1 (fr) Procédé d'application de compositions de liants minérales contenant des fibres
DE1771962A1 (de) Trockene Polymer-Zementmasse
EP2746237A1 (fr) Activateur pour ciment
EP0977716B1 (fr) Utilisation d'alcools comme additifs pour enduits et/ou mortiers
EP2313350B1 (fr) Procédé de dépoussiérage d'une composition pulvérulente de matériau de construction
DE102010034874B4 (de) Mineralische Bindemittelzusammensetzung und diese enthaltende bauchemische Produkte
CH682073A5 (fr)
EP2157069B1 (fr) Liant hydraulique revêtu
EP2313351B1 (fr) Compositions de matériau de construction en poudre contenant du dialkyle éther à chaîne longue
DE69902274T2 (de) Technologisches additiv zur agglomerierung von werfbaren baumaterialien und die verwendung dieser additive in werfbarem mörtel und beton
EP3630697B1 (fr) Mortier de ciment à base de résine époxy monocomposant
DE3825161A1 (de) Staubbindemittel fuer das betonspritzverfahren (ii)
WO2009130334A1 (fr) Utilisation d’hydrocarbures comme additifs pour réduire le dégagement de poussière de produits chimiques de construction
EP3538499B1 (fr) Accélérateur de durcissement
EP1394234B1 (fr) Entraîneur d'air avec poussiérage reduit
EP0352585B1 (fr) Suppresseur de poussière pour la pulvérisation de béton
EP3700967B1 (fr) Procédé de séchage par pulvérisation
DE202005021508U1 (de) Vorrichtung zum Verarbeiten von Baumaterial
EP4229019A1 (fr) Additif de matériau de construction pour des matériaux de construction à base de ciment
DE102020127379A1 (de) Baustoffadditiv für kalziumsulfatbasierte Baustoffe
DE102011113035B4 (de) Kalkfrischmörtelgebinde
EP2465835B1 (fr) Procédé de fabrication continue de masses de mortier
DE102022107704A1 (de) Trocknungsbeschleuniger für zementbasierte Baustoffe

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: 09735268

Country of ref document: EP

Kind code of ref document: A1

122 Ep: pct application non-entry in european phase

Ref document number: 09735268

Country of ref document: EP

Kind code of ref document: A1