Patents by Inventor Johannes Hoekstra

Johannes Hoekstra has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20200165450
    Abstract: Thermoplastic compositions are disclosed which include: a) a polyamide component comprising at least three amide monomer units and b) a stabilizer, wherein at least one of the at least three amide monomer units is an aliphatic amide monomer unit having a carbon to nitrogen ratio (C/N) equal to, or above 6.5, in that at least two of the at least three amide monomer units are semi-aromatic amide monomer units which polymerized provide at least one semi-crystalline semi-aromatic polyamide having a melting temperature of at least 290° C. as measured by DSC at a heating rate of 10° C./min according to standard ISO 11357-3 (2009), and in that the amount of aliphatic amide monomer unit is in the range from 20 to 60 wt. % relative to the total weight of the at least three amide monomer units in the polyamide components and the total amount of semi-aromatic amide monomer units is in the range from 40 to 80 wt.
    Type: Application
    Filed: January 31, 2020
    Publication date: May 28, 2020
    Inventors: Zhujuan WANG, Johannes HOEKSTRA, Pim Gerard Anton JANSSEN
  • Patent number: 10597534
    Abstract: The present invention relates to a thermoplastic composition comprising: a) a polyamide component comprising at least three amide monomer units and b) a stabilizer characterized in that at least one of the at least three amide monomer units is an aliphatic amide monomer unit having a carbon to nitrogen ratio (C/N) equal to, or above 6.5, in that at least two of the at least three amide monomer units are semi-aromatic amide monomer units which polymerized provide at least one semi-crystalline semi-aromatic polyamide having a melting temperature of at least 290° C. as measured by DSC at a heating rate of 10° C./min according to standard ISO 1 1357-3 (2009), and in that the amount of aliphatic amide monomer unit is in the range from 20 to 60 wt. % relative to the total weight of the at least three amide monomer units in the polyamide components and the total amount of semi-aromatic amide monomer units is in the range from 40 to 80 wt.
    Type: Grant
    Filed: September 29, 2015
    Date of Patent: March 24, 2020
    Assignee: DSM IP ASSETS B.V.
    Inventors: Zhujuan Wang, Johannes Hoekstra, Pim Gerard Anton Janssen
  • Patent number: 10577500
    Abstract: The invention relates to a process for the preparation of a semi-crystalline semi-aromatic polyamide copolymer (Co-PA) having a melting temperature (Tm-Co-PA) of at least 300° C., comprising steps of (a) preparing a first semi-crystalline semi-aromatic polyamide (A), having a melting temperature (Tm-A) of at least 310° C.; and consisting of repeat units derived from 45-50 mol % terephthalic acid; 47.
    Type: Grant
    Filed: June 26, 2014
    Date of Patent: March 3, 2020
    Assignee: DSM IP ASSETS B.V.
    Inventors: Johannes Hoekstra, Rudy Rulkens, Hans Klaas Dijk,Van
  • Patent number: 10377897
    Abstract: The invention relates to a laser-markable polyamide composition comprising: a first phase comprising Sb2O3 and an aliphatic polyamide with an amide density AD1, and a second phase comprising an aliphatic polyamide with an amide density AD2, wherein AD1-AD2 is at least 0.01, and wherein the amount of Sb2O3 is between 0.1 and 5 wt %, a halogen-free flame retardant in an amount of between 1 to 25 wt %, wherein the amount in weight percentage are based on the total amount of composition. The invention also relates to a process for preparing a laser-markable polyamide composition, as well as laser-marked products comprising the composition.
    Type: Grant
    Filed: May 18, 2015
    Date of Patent: August 13, 2019
    Assignee: DSM IP ASSETS B.V.
    Inventors: Raul Marcelino Perez Graterol, Franciscus Gerardus Henricus Van Duijnhoven, Franciscus Wilhelmus Maria Gelissen, Johannes Hoekstra
  • Patent number: 10113039
    Abstract: The invention relates to a process for producing shaped articles comprising the steps of: —compounding a polymer composition (A) containing a polyamide, a halogen-free melamine based flame retardant and at most 15 wt. % of glass fibers into pellets, compounding a polymer composition (B) containing a polyamide, more than 15 wt. % of glass fibers, and not containing halogen-free melamine based flame retardant into pellets, —producing a mixture comprising the pellets of polymer composition (A) and (B), —molding the mixture comprising the pellets of polymer composition (A) and (B) into shaped articles.
    Type: Grant
    Filed: April 20, 2015
    Date of Patent: October 30, 2018
    Assignee: DSM IP ASSETS B.V.
    Inventors: Johannes Hoekstra, Rui Zhang
  • Patent number: 10017628
    Abstract: The invention relates to a flame retarded thermoplastic moulding composition comprising (A) a polyamide (B) a flame retardant system comprising a metal salt of a phosphinic acid and/or a diphosphinic acid; and either (C) a fibrous reinforcing agent; or (D) an inorganic filler; or a combination of (C) and (D), wherein (A) consists primarily of a semi-crystalline semi-aromatic polyamide (A1) with a melting temperature of at least 310° C. and consisting of repeat units, predominantly derived from terephthalic acid and diamines selected from C2-C8 diamines and having a molar average number of carbon atoms of at most 7.
    Type: Grant
    Filed: July 9, 2014
    Date of Patent: July 10, 2018
    Assignee: DSM IP ASSETS B.V.
    Inventors: Johannes Hoekstra, Pim Gerard Anton Janssen
  • Publication number: 20170298225
    Abstract: The present invention relates to a thermoplastic composition comprising: a) a polyamide component comprising at least three amide monomer units and b) a stabilizer characterized in that at least one of the at least three amide monomer units is an aliphatic amide monomer unit having a carbon to nitrogen ratio (C/N) equal to, or above 6.5, in that at least two of the at least three amide monomer units are semi-aromatic amide monomer units which polymerized provide at least one semi-crystalline semi-aromatic polyamide having a melting temperature of at least 290° C. as measured by DSC at a heating rate of 10° C./min according to standard ISO 1 1357-3 (2009), and in that the amount of aliphatic amide monomer unit is in the range from 20 to 60 wt. % relative to the total weight of the at least three amide monomer units in the polyamide components and the total amount of semi-aromatic amide monomer units is in the range from 40 to 80 wt.
    Type: Application
    Filed: September 29, 2015
    Publication date: October 19, 2017
    Inventors: Zhujuan WANG, Johannes HOEKSTRA, Pim Gerard Anton JANSSEN
  • Publication number: 20170152382
    Abstract: The invention relates to a process for the preparation of a semi-crystalline semi-aromatic polyamide copolymer (Co-PA) having a melting temperature (Tm-Co-PA) of at least 300° C., comprising steps of (a) preparing a first semi-crystalline semi-aromatic polyamide (A), having a melting temperature (Tm-A) of at least 310° C.; and consisting of repeat units derived from 45-50 mol % terephthalic acid; 47.
    Type: Application
    Filed: June 26, 2014
    Publication date: June 1, 2017
    Inventors: Johannes HOEKSTRA, Rudy RULKENS, Hans Klaas DIJK,VAN
  • Publication number: 20170081513
    Abstract: The invention relates to a laser-markable polyamide composition comprising: a first phase comprising Sb2O3 and an aliphatic polyamide with an amide density AD1, and a second phase comprising an aliphatic polyamide with an amide density AD2, wherein AD1-AD2 is at least 0.01, and wherein the amount of Sb2O3 is between 0.1 and 5 wt %, a halogen-free flame retardant in an amount of between 1 to 25 wt %, wherein the amount in weight percentage are based on the total amount of composition. The invention also relates to a process for preparing a laser-markable polyamide composition, as well as laser-marked products comprising the composition.
    Type: Application
    Filed: May 18, 2015
    Publication date: March 23, 2017
    Inventors: Raul Marcelino PEREZ GRATEROL, Franciscus Gerardus Henricus VAN DUIJNHOVEN, Franciscus Wilhelmus Maria GELISSEN, Johannes HOEKSTRA
  • Publication number: 20170044336
    Abstract: The invention relates to a process for producing shaped articles comprising the steps of: —compounding a polymer composition (A) containing a polyamide, a halogen-free melamine based flame retardant and at most 15 wt. % of glass fibers into pellets, compounding a polymer composition (B) containing a polyamide, more than 15 wt. % of glass fibers, and not containing halogen-free melamine based flame retardant into pellets, —producing a mixture comprising the pellets of polymer composition (A) and (B), —molding the mixture comprising the pellets of polymer composition (A) and (B) into shaped articles.
    Type: Application
    Filed: April 20, 2015
    Publication date: February 16, 2017
    Applicant: DSM IP Assets B.V.
    Inventors: Johannes HOEKSTRA, Rui ZHANG
  • Patent number: 9399314
    Abstract: The present invention relates to a process for preparing an injection molded part, comprising the following steps: a preparing a glass fiber reinforced polyamide-6 composition with a relative viscosity of less than 2.4; b heating a such composition to obtain a viscous liquid; c filling a mold cavity with the viscous liquid with a filling time of at least 0.8 s; d leaving the viscous liquid in the mold under pressure until it cools to form a part; e opening the mold; f ejecting the part; wherein the polyamide-6 composition has a crystallization temperature under hyper DSC conditions of less than 168° C. The invention also relates to an injection molded part a having a maximum wall thickness of at least 2.5 mm; and/or b a part weight of at least 100 g per injection point; wherein the part consists of a glass fiber reinforced semi-crystalline polyamide-6 composition having a relative solution viscosity of less than 2.
    Type: Grant
    Filed: February 8, 2010
    Date of Patent: July 26, 2016
    Assignee: DSM IP ASSETS B.V.
    Inventors: Eric Willem Van Der Vegte, Johannes Hoekstra, Rudy Rulkens
  • Publication number: 20160152800
    Abstract: The invention relates to a flame retarded thermoplastic moulding composition comprising (A) a polyamide (B) a flame retardant system comprising a metal salt of a phosphinic acid and/or a diphosphinic acid; and either (C) a fibrous reinforcing agent; or (D) an inorganic filler; or a combination of (C) and (D), wherein (A) consists primarily of a semi-crystalline semi-aromatic polyamide (A1) with a melting temperature of at least 310° C. and consisting of repeat units, predominantly derived from terephthalic acid and diamines selected from C2-C8 diamines and having a molar average number of carbon atoms of at most 7.
    Type: Application
    Filed: July 9, 2014
    Publication date: June 2, 2016
    Inventors: Johannes HOEKSTRA, Pim Gerard Anton JANSSEN
  • Patent number: 9336964
    Abstract: The invention relates to an electrical circuit breaker comprising an arc formation chamber and an arc extinguishing chamber, the arc formation chamber being at least partially bounded by a side flange or at least a part of a side wall consisting of a polymeric composition comprising a thermoplastic polymer, a triazine based flame retardant, at most 0-5 wt. % of phosphorous or halogen containing flame retardants, and 0-15 wt. % of a reinforcing agent, wherein thermoplastic polymer comprises a polyamide with a melting temperature of at least 260° C. and the triazine based flame retardant comprises at least 20 wt. % of melam, wherein the weight percentages (wt. %) are relative to the total weight of the polymeric composition.
    Type: Grant
    Filed: June 17, 2011
    Date of Patent: May 10, 2016
    Assignee: DSM IP ASSETS B.V.
    Inventors: Rob Joseph Catharina Emiel Demandt, Johannes Hoekstra, Robert Hendrik Catharina Janssen
  • Patent number: 9006318
    Abstract: The present invention relates to a polyamide composition comprising (amounts are based on the total composition) (A) polyamide, (B) melamine cyanurate and (C) talcum as mineral filler wherein the amount of talcum is higher than 25 wt %, and the weight ratio melamine cyanurate/talcum is higher than ? and to articles made wholly or partly of this polyamide composition. The polyamide is preferably polyamide 6. The composition is commonly used in the industry of for instance electrical and electronic parts and preferably in miniature circuit breakers.
    Type: Grant
    Filed: July 8, 2009
    Date of Patent: April 14, 2015
    Assignee: DSM IP Assets B.V.
    Inventors: Johannes Hoekstra, Jeroen Joost Crevecoeur, Jin Ye
  • Publication number: 20140371357
    Abstract: The invention relates to plastic component for use as a live part in unattended household appliances, complying with IEC 60335 and/or VDE approval for use in unattended household appliances, wherein the plastic component is made from a halogen free flame retardant polymer composition comprising (A) a thermoplastic polyamide polymer; (B) 10-40 wt. % of glass fibers; (C) 10-40 wt. % of melam; and (D) 0-15 wt. % of a halogen free flame retardant; wherein the wt. % are relative to the total weight of the composition; with the proviso that when the polyamide or polyamides in component (A) consist of monomeric units comprising less than 10 mole % of aromatic units, relative to the total molar amount of the monomeric units, the amount of melam (C) is in the range of 15-40 wt. %.
    Type: Application
    Filed: December 11, 2012
    Publication date: December 18, 2014
    Inventors: Johannes Hoekstra, Josien Krijgsman, Rui Zhang
  • Publication number: 20130200046
    Abstract: The invention relates to an electrical circuit breaker comprising an arc formation chamber and an arc extinguishing chamber, the arc formation chamber being at least partially bounded by a side flange or at least a part of a side wall consisting of a polymeric composition comprising a thermoplastic polymer, a triazine based flame retardant, at most 0-5 wt. % of phosphorous or halogen containing flame retardants, and 0-15 wt. % of a reinforcing agent, wherein thermoplastic polymer comprises a polyamide with a melting temperature of at least 260° C. and the triazine based flame retardant comprises at least 20 wt. % of melam, wherein the weight percentages (wt. %) are relative to the total weight of the polymeric composition.
    Type: Application
    Filed: June 17, 2011
    Publication date: August 8, 2013
    Applicant: DSM IP ASSETTS B.V.
    Inventors: Rob Joseph Catharina Emiel Demandt, Johannes Hoekstra, Robert Hendrik Catharina Janssen
  • Publication number: 20120043700
    Abstract: The present invention relates to a process for preparing an injection molded part, comprising the following steps: a preparing a glass fiber reinforced polyamide-6 composition with a relative viscosity of less than 2.4; b heating a such composition to obtain a viscous liquid; c filling a mold cavity with the viscous liquid with a filling time of at least 0.8 s; d leaving the viscous liquid in the mold under pressure until it cools to form a part; e opening the mold; f ejecting the part; wherein the polyamide-6 composition has a crystallization temperature under hyper DSC conditions of less than 168° C. The invention also relates to an injection molded part a having a maximum wall thickness of at least 2.5 mm; and/or b a part weight of at least 100 g per injection point; wherein the part consists of a glass fiber reinforced semi-crystalline polyamide-6 composition having a relative solution viscosity of less than 2.
    Type: Application
    Filed: February 8, 2010
    Publication date: February 23, 2012
    Inventors: Eric Willem Van Der Vegte, Johannes Hoekstra, Rudy Rulkens
  • Publication number: 20110288265
    Abstract: The invention relates to a plastic container or conduit for a cooling system, a heating system, an air intake system, an exhaust system, a pressure system or a fuel system, consisting of or comprising a part or a layer made of a thermoplastic polymer composition comprising a semi-crystalline semi-aromatic polyamide having a glass transition temperature (Tg) of at least 115° C.
    Type: Application
    Filed: January 21, 2010
    Publication date: November 24, 2011
    Inventors: Eric W. Vegte Van Der, Johannes Hoekstra
  • Publication number: 20110207862
    Abstract: The present invention relates to a polyamide composition comprising (amounts are based on the total composition) (A) polyamide, (B) melamine cyanurate and (C) talcum as mineral filler wherein the amount of talcum is higher than 25 wt %, and the weight ratio melamine cyanurate/talcum is higher than ? and to articles made wholly or partly of this polyamide composition. The polyamide is preferably polyamide 6. The composition is commonly used in the industry of for instance electrical and electronic parts and preferably in miniature circuit breakers.
    Type: Application
    Filed: July 8, 2009
    Publication date: August 25, 2011
    Inventors: Johannes Hoekstra, Jeroen Joost Crevecoeur, Jin Ye
  • Publication number: 20100196507
    Abstract: A synthesized composition containing zinc ions, calcium ions, rubidium ions and/or potassium ions in a pharmaceutically acceptable carrier, which, when applied to an open wound, effectively modulates the activity of at least MMP-2 and/or MMP-9 in the wound. A method for treatment of wounds is disclosed.
    Type: Application
    Filed: September 23, 2009
    Publication date: August 5, 2010
    Applicant: GREYSTONE MEDICAL GROUP, INC.
    Inventors: Stephen H. MONROE, Matthias Johannes HOEKSTRA