GB2068819A - Polyurethane mouldings - Google Patents

Polyurethane mouldings Download PDF

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Publication number
GB2068819A
GB2068819A GB8004772A GB8004772A GB2068819A GB 2068819 A GB2068819 A GB 2068819A GB 8004772 A GB8004772 A GB 8004772A GB 8004772 A GB8004772 A GB 8004772A GB 2068819 A GB2068819 A GB 2068819A
Authority
GB
United Kingdom
Prior art keywords
mould
moulding
polyvinyl chloride
plastisol
plasticiser
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.)
Withdrawn
Application number
GB8004772A
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.)
ExxonMobil Technology and Engineering Co
Original Assignee
Exxon Research and Engineering Co
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 Exxon Research and Engineering Co filed Critical Exxon Research and Engineering Co
Priority to GB8004772A priority Critical patent/GB2068819A/en
Publication of GB2068819A publication Critical patent/GB2068819A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • 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
    • B29C33/00—Moulds or cores; Details thereof or accessories therefor
    • B29C33/56—Coatings, e.g. enameled or galvanised; Releasing, lubricating or separating agents
    • B29C33/60—Releasing, lubricating or separating agents
    • B29C33/62—Releasing, lubricating or separating agents based on polymers or oligomers
    • 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
    • B29C44/36—Feeding the material to be shaped
    • B29C44/38—Feeding the material to be shaped into a closed space, i.e. to make articles of definite length
    • B29C44/42—Feeding the material to be shaped into a closed space, i.e. to make articles of definite length using pressure difference, e.g. by injection or by vacuum
    • 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
    • B29C33/00—Moulds or cores; Details thereof or accessories therefor
    • B29C33/56—Coatings, e.g. enameled or galvanised; Releasing, lubricating or separating agents
    • 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
    • B29C37/00—Component parts, details, accessories or auxiliary operations, not covered by group B29C33/00 or B29C35/00
    • B29C37/0025—Applying surface layers, e.g. coatings, decorative layers, printed layers, to articles during shaping, e.g. in-mould printing
    • B29C37/0028—In-mould coating, e.g. by introducing the coating material into the mould after forming the article
    • 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
    • B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
    • B29K2027/06—PVC, i.e. polyvinylchloride
    • 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
    • B29K2075/00—Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Compositions Of Macromolecular Compounds (AREA)

Abstract

A polyvinyl chloride plastisol is initially sprayed onto the interior surface of the mould in the injection moulding of articles from polyurethanes. The plastisol sticks to the surface of the moulded article and can be coloured to colour the surface of the moulding. It also acts as a mould release agent. The plastisol layer may be cured in the mould prior to injection of the urethane forming mixture, if desired.

Description

SPECIFICATION Moulding polymers The present invention relates to improvements in or relating to the moulding of polyurethanes. Polyurethane articles are typically produced by injecting a mixture of a polyol, polyether or polyester and a diisocyanate into a mould where the two react exothermically and cure to form the solid moulded article.
The reactive being stored separately and mixed immediately before injection into the mould.
The surface of the mould which is usually metallic is coated with a mould release agent to prevent the moulding sticking to the surface of the mould so enhancing the surface finish. Silicones which stick to the surface are generally used and one problem with the use of silicones is that they tend to stick to the surface of the moulding making it difficult to paint.
A typical moulding cycle is about four minutes in which about 21 minutes allow for preparation of the mould. The remainder being for injection of material into the mould, the exothermic reaction and the curing of the moulding.
We have now found that if the interior surface of the mould is sprayed with a polyvinyl chloride plastisol the plastisol will act as a mould release agent; will stick to the surface of the moulding yielding a good surface finish. Furthermore, since the plastisol may be coloured the technique also allows the desired surface colour to be imparted to the moulding.
The present invention therefore provides the use as a mould release agent in the production of polyurethane mouldings of a polyvinyl chloride plastisol.
The present invention further provides a moulding cycle for the preparation of polyurethane mouldings comprising spraying a polyvinyl chloride plasticiser onto the interior surface of the mould subsequently injecting the urethane forming mixture into the mould allowing the mixture to react and cure in the mould and removing the so formed moulding.
Throughout this specification the term polyvinyl chloride plastisol is used to describe a free flowing liquid comprising particles of a thermoplastic polymer generally polyvinyl chloride suspended in plasticiser and the plasticiser composition may contain other materials such as stabilisers, fillers and antioxidants.
Any of the well known plasticiser compositions may be used in the process of our invention. Our preferred plasticiser for polyvinyl chloride are the phthalate, adipte, azelate and sebacate esters, preferably the C4-C,3 esters.
The polyvinyl chloride plastisol should be gelled either before or during the moulding cycle to ensure adhesion to the surface of the moulding and to give the moulding the desired surface finish. The gelling temperature of the polyvinyl chloride plastisol depends upon the particular plasticiser used although typically temperatures of around 60 C are required. If the temperature of the surface of the polyurethane during the exothermic curing reaction does not reach this temperature then the layer of polyvinyl chloride plastisol may conveniently be cured by injecting hot air into the mould following spraying of the polyvinyl chloride plastisol layer and before injection of the urethane forming mixture.
The present invention is applicable to all polyurethane mouldings and all sizes. The polyurethane may be derived from tolyene diisocyanate or di-isocyanate and is especially useful in the production of large mouldings such as panels for automobiles.
1. The use as a mould release agent in the production of polyurethane mouldings of a polyvinyl chloride plastisol.
2. A moulding cycle for the preparation of polyurethane mouldings comprising spraying a polyvinyl chloride plasticiser onto the interior surface of the mould subsequently injecting the urethane forming mixture into the mould allowing the mixture to react and cure in the mould and removing the so formed moulding.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (2)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Moulding polymers The present invention relates to improvements in or relating to the moulding of polyurethanes. Polyurethane articles are typically produced by injecting a mixture of a polyol, polyether or polyester and a diisocyanate into a mould where the two react exothermically and cure to form the solid moulded article. The reactive being stored separately and mixed immediately before injection into the mould. The surface of the mould which is usually metallic is coated with a mould release agent to prevent the moulding sticking to the surface of the mould so enhancing the surface finish. Silicones which stick to the surface are generally used and one problem with the use of silicones is that they tend to stick to the surface of the moulding making it difficult to paint. A typical moulding cycle is about four minutes in which about 21 minutes allow for preparation of the mould. The remainder being for injection of material into the mould, the exothermic reaction and the curing of the moulding. We have now found that if the interior surface of the mould is sprayed with a polyvinyl chloride plastisol the plastisol will act as a mould release agent; will stick to the surface of the moulding yielding a good surface finish. Furthermore, since the plastisol may be coloured the technique also allows the desired surface colour to be imparted to the moulding. The present invention therefore provides the use as a mould release agent in the production of polyurethane mouldings of a polyvinyl chloride plastisol. The present invention further provides a moulding cycle for the preparation of polyurethane mouldings comprising spraying a polyvinyl chloride plasticiser onto the interior surface of the mould subsequently injecting the urethane forming mixture into the mould allowing the mixture to react and cure in the mould and removing the so formed moulding. Throughout this specification the term polyvinyl chloride plastisol is used to describe a free flowing liquid comprising particles of a thermoplastic polymer generally polyvinyl chloride suspended in plasticiser and the plasticiser composition may contain other materials such as stabilisers, fillers and antioxidants. Any of the well known plasticiser compositions may be used in the process of our invention. Our preferred plasticiser for polyvinyl chloride are the phthalate, adipte, azelate and sebacate esters, preferably the C4-C,3 esters. The polyvinyl chloride plastisol should be gelled either before or during the moulding cycle to ensure adhesion to the surface of the moulding and to give the moulding the desired surface finish. The gelling temperature of the polyvinyl chloride plastisol depends upon the particular plasticiser used although typically temperatures of around 60 C are required. If the temperature of the surface of the polyurethane during the exothermic curing reaction does not reach this temperature then the layer of polyvinyl chloride plastisol may conveniently be cured by injecting hot air into the mould following spraying of the polyvinyl chloride plastisol layer and before injection of the urethane forming mixture. The present invention is applicable to all polyurethane mouldings and all sizes. The polyurethane may be derived from tolyene diisocyanate or di-isocyanate and is especially useful in the production of large mouldings such as panels for automobiles. CLAIMS
1. The use as a mould release agent in the production of polyurethane mouldings of a polyvinyl chloride plastisol.
2. A moulding cycle for the preparation of polyurethane mouldings comprising spraying a polyvinyl chloride plasticiser onto the interior surface of the mould subsequently injecting the urethane forming mixture into the mould allowing the mixture to react and cure in the mould and removing the so formed moulding.
GB8004772A 1980-02-13 1980-02-13 Polyurethane mouldings Withdrawn GB2068819A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8004772A GB2068819A (en) 1980-02-13 1980-02-13 Polyurethane mouldings

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8004772A GB2068819A (en) 1980-02-13 1980-02-13 Polyurethane mouldings

Publications (1)

Publication Number Publication Date
GB2068819A true GB2068819A (en) 1981-08-19

Family

ID=10511314

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8004772A Withdrawn GB2068819A (en) 1980-02-13 1980-02-13 Polyurethane mouldings

Country Status (1)

Country Link
GB (1) GB2068819A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0288457A4 (en) * 1986-08-04 1988-08-23 Brian M Kelly Method for injection molding with improved mold primer.
GB2229392A (en) * 1989-03-15 1990-09-26 Austin Rover Group Forming a fibre reinforced thermoplastic article
GB2262468A (en) * 1991-12-19 1993-06-23 Yad Hygiene Products Limited Moulding polymeric articles having a biocidally active surface
GB2286795B (en) * 1992-09-24 1997-04-30 Fuller H B Co Coated Substrates
WO2017046300A1 (en) * 2015-09-16 2017-03-23 3D-Side Implant molding system

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0288457A4 (en) * 1986-08-04 1988-08-23 Brian M Kelly Method for injection molding with improved mold primer.
EP0288457A1 (en) * 1986-08-04 1988-11-02 KELLY, Brian M. Method for injection molding with improved mold primer
GB2229392A (en) * 1989-03-15 1990-09-26 Austin Rover Group Forming a fibre reinforced thermoplastic article
GB2262468A (en) * 1991-12-19 1993-06-23 Yad Hygiene Products Limited Moulding polymeric articles having a biocidally active surface
GB2286795B (en) * 1992-09-24 1997-04-30 Fuller H B Co Coated Substrates
WO2017046300A1 (en) * 2015-09-16 2017-03-23 3D-Side Implant molding system

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Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)