FR1251267A - Procédé pour la fabrication d'éléments légers utilisables en particulier en construction - Google Patents

Procédé pour la fabrication d'éléments légers utilisables en particulier en construction

Info

Publication number
FR1251267A
FR1251267A FR809721A FR809721A FR1251267A FR 1251267 A FR1251267 A FR 1251267A FR 809721 A FR809721 A FR 809721A FR 809721 A FR809721 A FR 809721A FR 1251267 A FR1251267 A FR 1251267A
Authority
FR
France
Prior art keywords
manufacture
construction
lightweight elements
lightweight
elements
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.)
Expired
Application number
FR809721A
Other languages
English (en)
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.)
Houilleres du Bassin du Nord et du Pas de Calais
Original Assignee
Houilleres du Bassin du Nord et du Pas de Calais
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
Priority to NL257593D priority Critical patent/NL257593A/xx
Application filed by Houilleres du Bassin du Nord et du Pas de Calais filed Critical Houilleres du Bassin du Nord et du Pas de Calais
Priority to FR809721A priority patent/FR1251267A/fr
Priority to BE596105A priority patent/BE596105A/fr
Priority to LU39305D priority patent/LU39305A1/xx
Priority to GB36738/60A priority patent/GB900960A/en
Priority to US66777A priority patent/US3194708A/en
Priority to DE19601494109 priority patent/DE1494109C/de
Priority to SE10694/60A priority patent/SE300500B/xx
Application granted granted Critical
Publication of FR1251267A publication Critical patent/FR1251267A/fr
Expired legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/36—After-treatment
    • C08J9/365—Coating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
    • B29C44/02—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles for articles of definite length, i.e. discrete articles
    • B29C44/12—Incorporating or moulding on preformed parts, e.g. inserts or reinforcements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C44/00—Shaping by internal pressure generated in the material, e.g. swelling or foaming ; Producing porous or cellular expanded plastics articles
    • B29C44/34—Auxiliary operations
    • B29C44/56—After-treatment of articles, e.g. for altering the shape
    • B29C44/5618—Impregnating foam articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
    • B29C70/003—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts characterised by the matrix material, e.g. material composition or physical properties
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/34—Chemical features in the manufacture of articles consisting of a foamed macromolecular core and a macromolecular surface layer having a higher density than the core
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
    • E04C2/02—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials
    • E04C2/10—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of wood, fibres, chips, vegetable stems, or the like; of plastics; of foamed products
    • E04C2/20—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of wood, fibres, chips, vegetable stems, or the like; of plastics; of foamed products of plastics
    • E04C2/205—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of wood, fibres, chips, vegetable stems, or the like; of plastics; of foamed products of plastics of foamed plastics, or of plastics and foamed plastics, optionally reinforced
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
    • E04C2/02—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials
    • E04C2/10—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of wood, fibres, chips, vegetable stems, or the like; of plastics; of foamed products
    • E04C2/20—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of wood, fibres, chips, vegetable stems, or the like; of plastics; of foamed products of plastics
    • E04C2/22—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials of wood, fibres, chips, vegetable stems, or the like; of plastics; of foamed products of plastics reinforced
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2309/00—Use of inorganic materials not provided for in groups B29K2303/00 - B29K2307/00, as reinforcement
    • B29K2309/08—Glass
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2327/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers
    • C08J2327/02—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment
    • C08J2327/04—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Derivatives of such polymers not modified by chemical after-treatment containing chlorine atoms
    • C08J2327/06—Homopolymers or copolymers of vinyl chloride
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
    • C08J2367/06—Unsaturated polyesters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/23—Sheet including cover or casing
    • Y10T428/233—Foamed or expanded material encased
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/23—Sheet including cover or casing
    • Y10T428/239—Complete cover or casing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249955—Void-containing component partially impregnated with adjacent component
    • Y10T428/249958—Void-containing component is synthetic resin or natural rubbers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249982—With component specified as adhesive or bonding agent
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/249921—Web or sheet containing structurally defined element or component
    • Y10T428/249953—Composite having voids in a component [e.g., porous, cellular, etc.]
    • Y10T428/249982—With component specified as adhesive or bonding agent
    • Y10T428/249985—Composition of adhesive or bonding component specified

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Architecture (AREA)
  • Health & Medical Sciences (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Polymers & Plastics (AREA)
  • Civil Engineering (AREA)
  • Medicinal Chemistry (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
  • Composite Materials (AREA)
  • Mathematical Physics (AREA)
  • Mechanical Engineering (AREA)
  • Laminated Bodies (AREA)
  • Moulding By Coating Moulds (AREA)
FR809721A 1959-11-07 1959-11-07 Procédé pour la fabrication d'éléments légers utilisables en particulier en construction Expired FR1251267A (fr)

Priority Applications (8)

Application Number Priority Date Filing Date Title
NL257593D NL257593A (fr) 1959-11-07
FR809721A FR1251267A (fr) 1959-11-07 1959-11-07 Procédé pour la fabrication d'éléments légers utilisables en particulier en construction
BE596105A BE596105A (fr) 1959-11-07 1960-10-17 Procédé pour la fabrication d'éléments legers utilisables en particulier en construction.
LU39305D LU39305A1 (fr) 1959-11-07 1960-10-19
GB36738/60A GB900960A (en) 1959-11-07 1960-10-26 Production of light structural members
US66777A US3194708A (en) 1959-11-07 1960-11-02 Production of light structural members
DE19601494109 DE1494109C (de) 1959-11-07 1960-11-04 Mehrstufiges Verfahren zum Herstellen spezifisch leichter, mehrschichtiger Form teile mit einem schaumförmigen, porösen Kern aus Polyvinylchlorid
SE10694/60A SE300500B (fr) 1959-11-07 1960-11-07

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR809721A FR1251267A (fr) 1959-11-07 1959-11-07 Procédé pour la fabrication d'éléments légers utilisables en particulier en construction

Publications (1)

Publication Number Publication Date
FR1251267A true FR1251267A (fr) 1961-01-20

Family

ID=8721084

Family Applications (1)

Application Number Title Priority Date Filing Date
FR809721A Expired FR1251267A (fr) 1959-11-07 1959-11-07 Procédé pour la fabrication d'éléments légers utilisables en particulier en construction

Country Status (7)

Country Link
US (1) US3194708A (fr)
BE (1) BE596105A (fr)
FR (1) FR1251267A (fr)
GB (1) GB900960A (fr)
LU (1) LU39305A1 (fr)
NL (1) NL257593A (fr)
SE (1) SE300500B (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2514056A1 (fr) * 1981-10-05 1983-04-08 Durafour Construction Element de construction composite autoportant
EP0245816A2 (fr) * 1986-05-12 1987-11-19 Kawasaki Jukogyo Kabushiki Kaisha Elément de structure renforcé de fibres

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3302362A (en) * 1963-12-10 1967-02-07 Keith M Lang Method for forming roof structure
US3327441A (en) * 1963-12-27 1967-06-27 Union Carbide Corp Insulating panel assembly with a resinous impregnated support member
US3493460A (en) * 1966-11-21 1970-02-03 Dow Chemical Co Fire retardant laminate
US3627622A (en) * 1967-09-29 1971-12-14 Dow Chemical Co Partial resin coated foamed resinous articles
US4125664A (en) * 1974-07-13 1978-11-14 Herbert Giesemann Shaped articles of foam plastics
US4130685A (en) * 1974-09-20 1978-12-19 Tarullo John A Cork wall covering
US3944704A (en) * 1974-10-31 1976-03-16 The John Z. Delorean Corporation Composite structure
US4042746A (en) * 1975-11-07 1977-08-16 The John Z. Delorean Corporation Composite material and method of forming
EP0060356A1 (fr) * 1981-03-18 1982-09-22 Linx Building Systems Corporation Panneau de construction composite
GB2120167B (en) * 1982-04-21 1986-07-09 Beldale Investments Ltd A deformable structure and method of using such a structure
DE3564840D1 (en) * 1984-07-27 1988-10-13 Abs Brandschutz Accessible protection enclosure
US4764238A (en) * 1985-08-23 1988-08-16 Grumman Aerospace Corporation Energy absorbing foam-fabric laminate
US4844975A (en) * 1988-03-04 1989-07-04 Bally Engineered Structures, Inc. Reinforced composite sandwich panel assembly
DE3907510A1 (de) * 1989-01-09 1990-09-13 Albert Kubbutat Halteeinrichtung zum befestigen von fassadenplatten
US5098059A (en) * 1990-04-11 1992-03-24 Sawyer Robert D Concrete forming member for use in concrete casting
WO1997010396A1 (fr) * 1995-09-11 1997-03-20 Dow Europe S.A. Planches thermoplastiques destinees a un plancher
US20070051060A1 (en) * 2005-05-21 2007-03-08 Moore P K Structural elements and method for fabricating structural elements
US20100198414A1 (en) * 2007-06-28 2010-08-05 Kroll Steven C Systems and methods for controlling interior climates
CA2803069A1 (fr) * 2009-01-21 2010-07-29 Peter Barretto Materiau composite a base de cuir colle

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2482798A (en) * 1946-02-27 1949-09-27 Jr George B Rheinfrank Aircraft wing and method of manufacture
FR1075345A (fr) * 1953-02-06 1954-10-14 Prod G A L Soc Ind Des Matériaux composés
US2839442A (en) * 1955-02-23 1958-06-17 Smith Corp A O Process of making a lightweight structural panel
US2875117A (en) * 1955-08-29 1959-02-24 Haskelite Mfg Corp Multilaminar panel
BE563462A (fr) * 1956-12-27 1900-01-01

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2514056A1 (fr) * 1981-10-05 1983-04-08 Durafour Construction Element de construction composite autoportant
EP0077701A1 (fr) * 1981-10-05 1983-04-27 SOCIETE DE CONSTRUCTION DURAFOUR Société dite: Elément de construction composite autoportant
EP0245816A2 (fr) * 1986-05-12 1987-11-19 Kawasaki Jukogyo Kabushiki Kaisha Elément de structure renforcé de fibres
EP0245816A3 (en) * 1986-05-12 1989-05-10 Kawasaki Jukogyo Kabushiki Kaisha Fiber reinforced structural member

Also Published As

Publication number Publication date
SE300500B (fr) 1968-04-29
GB900960A (en) 1962-07-11
LU39305A1 (fr) 1960-12-19
DE1494109B2 (de) 1972-08-03
BE596105A (fr) 1961-02-15
DE1494109A1 (de) 1969-02-06
US3194708A (en) 1965-07-13
NL257593A (fr) 1900-01-01

Similar Documents

Publication Publication Date Title
FR1251267A (fr) Procédé pour la fabrication d'éléments légers utilisables en particulier en construction
BE586230A (fr) Procédé pour la fabrication d'eupolyoxyméthylènes
FR1286109A (fr) Composition et procédé pour la fabrication de meules usantes et articles similaires
BE588736A (fr) Procédé pour la fabrication d'halogénures d'alcalamine.
CH364473A (fr) Procédé de fabrication d'éléments tubulaires métalliques
FR1165357A (fr) Procédé pour la fabrication de pivots et axes, en particulier pour montres
BE606723A (fr) Procédé pour la fabrication d'eupolyoxyméthylenes.
BE597826A (fr) Procédé pour la fabrication de carbure d'uranium
BE593014A (fr) Procédé pour la fabrication d'acide peroxymonophosphorique
BE602539A (fr) Procédé de fabrication d'arylaminopyrazoles
BE591967A (fr) Procédé pour la fabrication d'acides 2-nitro-4-fluorobenzoïques et 4-nitro-2-fluorobenzoïques.
FR1224560A (fr) Procédé et appareillage pour la fabrication de l'urée
FR72590E (fr) Procédé pour la fabrication d'éléments de construction
FR1246751A (fr) Procédé et appareillage pour la fabrication rapide d'éléments mosaïques et similaires
FR1211182A (fr) Procédé de fabrication d'éléments de construction
FR1287324A (fr) Procédé pour la fabrication d'arylsulfonylurée
FR1237793A (fr) Procédé de fabrication d'éléments de construction
FR69891E (fr) Procédé pour la fabrication d'éléments de construction
BE595407A (fr) Procédé pour la fabrication de cyclotriméthylènetrinitramine.
FR1254004A (fr) Procédé de fabrication d'éléments tubulaires métalliques
FR1188916A (fr) Procédé pour la fabrication d'aiguilles, notamment pour l'horlogerie
FR1270525A (fr) Procédé pour la fabrication de corps creux
FR1250930A (fr) Procédé pour la fabrication de cyclo-dodécatriènes-(1, 5, 9)
FR1240702A (fr) Matière sableuse, en particulier pour la fabrication de mortiers et de bétons
FR1239506A (fr) Procédé pour la fabrication de sulfaméthylpyrimidine