US 2003.0143413A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2003/0143413 A1 Storbeck et al. (43) Pub. Date: Jul. 31, 2003 (54) PRODUCING PRESSURE-SENSITIVELY (30) Foreign Application Priority Data ADHESIVE PUNCHED PRODUCTS Nov. 22, 2001 (DE)..................................... 101 57 1534 (75) Inventors: Reinhard Storbeck, Hamburg (DE); Marc Husemann, Hamburg (DE); Publication Classification Matthias Koch, Hamburg (DE); Maren Klose, Seevetal (DE) (51) Int. Cl." ........................... B32B 27/00; B32B 27/30 (52) U.S. Cl. ............................................ 428/500; 428/522 Correspondence Address: KURT BRISCOE NORRIS, MCLAUGHLIN & MARCUS, PA. (57) ABSTRACT 220NEW EAST YORK, 42ND NY STREET, 10017 (US) 30TH FLOOR A process for producing preSSure-Sensitively adhesive punched products from backing material coated with pres (73) Assignee: tesa Aktiengesellschaft Sure Sensitive adhesive, wherein Said pressure Sensitive adhesive is oriented Such that it (21) Appl. No.: 10/219,523 possesses a preferential direction and, (22) Filed: Aug. 15, 2002 the punching process is carried out continuously. Patent Application Publication Jul. 31, 2003 Sheet 1 of 5 US 2003/0143413 A1 var- - - - - - - - - - mm Et= SOC kW Siga A - 726.6nm WD = 5 m Signal B = Fig. 1 Patent Application Publication Jul. 31, 2003. Sheet 2 of 5 US 2003/0143413 A1 Fig. 3 Patent Application Publication Jul. 31, 2003. Sheet 3 of 5 US 2003/0143413 A1 mid Patent Application Publication Jul. 31, 2003 Sheet 4 of 5 US 2003/0143413 A1 YMemorrOOOOL way www.scriptwrenna DODOO ODOOO OOOOO md OOOOO DDDDD DODOO . OOOOO 3DOOOO. mid Patent Application Publication Jul. 31, 2003. Sheet 5 of 5 US 2003/0143413 A1 US 2003/0143413 A1 Jul. 31, 2003 PRODUCING PRESSURE-SENSITIVELY 0008 Anisotropically oriented PSAS possess the ten ADHESIVE PUNCHED PRODUCTS dency to move back into the initial State following Stretching in a given direction, as a result of their “entropy-elastic' 0001. The invention relates to a process for producing behavior. punched products and to punched products thus obtainable. 0009 Suitable in principle for the inventive process are 0002 All presently known pressure sensitive adhesives all PSAS which exhibit an orientation, examples being those (PSAs) are characterized by a more or less pronounced flow based on natural or synthetic rubbers such as butyl rubber, behavior. When strongly pronounced, this flow behavior is neoprene, butadiene-acrylonitrile, Styrene-butadiene-Styrene also known as the cold flow or bleeding of a PSA. This copolymers and Styrene-isoprene-Styrene copolymers, and inherent behavior of a PSA leads to problems when punch also those based on linear polyesters and copolyesters, ing Self-adhesive materials. The two common punching polyurethanes, polysiloxane elastomers, based on acrylic methods, flatbed punching and rotary punching, are affected block copolymers, especially those with diblocks and/or by these problems. For example, punched products may be triblocks, in which at least one block component is based on removed as well during matrix Stripping, because the cold polyacrylates, and, additionally, PSAS based on Straight flow of a PSA does not allow clean separation of the acrylics, but with very Special advantage anisotropic PSAS adhesive. Where matrix Stripping is carried out manually based on polyacrylate and/or polymethacrylate. after the punching operation, as in Asia, for example, these problems are exacerbated, Since the adhesive then has Suf 0010) Surprisingly, in the form of a layer, anisotropically ficient time available to coalesce. oriented acrylic PSAs of this kind exhibit resilience of the PSA film following punching and/or cutting operations, at 0003) A further problem arises in the kiss-cut process. In the cut and punched edge, this recession being utilized the kiss-cutting of Self-adhesive materials, the release mate inventively for the punching of shapes which do not flow rial is part-punched as well, i.e., the punching tools penetrate together again (coalesce). This property is not known for any to a more or leSS defined depth into the Substrate material of the pressure sensitive adhesives which have hitherto (=release material). As a result, the antiadhesively finished belonged to the state of the art. (FIG. 1 shows one edge of Surface of the release material (in the majority of cases, the a punched product of this kind following the punching release materials are Siliconized; this applies to all release Systems described; Satas, 3rd edition, chapters 26 and 27) is process. The recession of the pressure Sensitive adhesive, always destroyed. The adhesive is able to flow into the caused by anisotropic orientation, can be seen.) substrate material of the release material (paper, PET, PP, 0011. The monomers are preferably chosen such that the PE) and adhere. The punched product can no longer be resulting polymers can be used as pressure Sensitive adhe removed readily from the Siliconized release material, Since Sives at room temperature or at higher temperatures, espe the edges of the punched product are Stuck to the Substrate. cially Such that the resulting polymers possess pressure In a downstream processing Step, Such as automatic dispens Sensitively adhering properties in accordance with the ing, for example, the punched product or the matrix lattice “Handbook of Pressure Sensitive Adhesive Technology” by Surrounding the punched products and intended for removal Donatas Satas (van Nostrand, New York, 1989). may tear during Stripping. Such tears nowadays cause mas Sive disruptions to production. The effects described apply to 0012. The polymers which can be used with preference all product Structures, Such as adhesive transfer tapes, and for the inventive process are preferably obtainable by poly also to Substrates coated on one or both Sides, Such as films, merizing a monomer mixture composed of acrylic esters nonwovens, papers, layS or foams. and/or methacrylic esters and/or their free acids with the formula CH=CH(R)(COOR), where R=H or CH and 0004. It is an object of the invention, therefore, to R is an alkyl chain having 1-20 carbon atoms or H. improve the production of punched products by avoiding, or else at least considerably reducing, the above-described 0013 The molar masses M of the polyacrylates used are disadvantages of the prior art. preferably 2200 000 g/mol. 0005 Surprisingly and in a manner unforeseeable for the 0014 Very preferably, use is made for the inventive skilled worker, this object is achieved through the use of process of acrylic or methacrylic monomers composed of anisotropic pressure Sensitive adhesives in the punching acrylates and methacrylates having alkyl groups of 4 to 14 process. The main claim accordingly relates to a proceSS for carbon atoms, preferably from 4 to 9 carbon atoms. Specific producing pressure Sensitively adhesive punched products examples, without wishing to be restricted by this listing, from backing material provided with a preSSure Sensitive include methyl acrylate, methyl methacrylate, ethyl acrylate, adhesive, Said pressure Sensitive adhesive being anisotropic n-butyl acrylate, n-butyl methacrylate, n-pentyl acrylate, by Virtue of possessing a preferential direction, and the n-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, n-octyl punching proceSS being carried out continuously. The Sub methacrylate, n-nonyl acrylate, lauryl acrylate, Stearyl acry late, behenyl acrylate, and the branched isomers thereof, claims relate to preferred developments of this process. Such as isobutyl acrylate, 2-ethylhexyl acrylate, 2-ethyl Further claims relate to the punched products thus obtain hexyl methacrylate, isooctyl acrylate, and isooctyl meth able. acrylate, for example. 0006 Pressure Sensitive Adhesives 0015. Further classes of compounds which can be used 0007 Anisotropic pressure sensitive adhesives which can include monofunctional acrylates and methacrylates of be employed for the inventive proceSS are Sometimes bridged cycloalkyl alcohols, composed of at least 6 carbon referred to below as anisotropically oriented, or Simply as atoms. The cycloalkyl alcohols may also be Substituted, by oriented, PSAS. C-6 alkyl groups, halogen atoms or cyano groups, for US 2003/0143413 A1 Jul. 31, 2003 example. Specific examples include cyclohexyl methacry phenyl methacrylate, t-butylphenyl acrylate, t-butylphenyl lates, isobornyl acrylate, isobornyl methacrylate and 3,5- methacrylate, 4-biphenyl acrylate and methacrylate, 2-naph dimethyladamanty1 acrylate. thyl acrylate and methacrylate, and mixtures of those mono 0016. In one procedure monomers are used which carry mers, this list not being conclusive. polar groupS. Such as carboxyl radicals, Sulfonic and phoS 0022. For the inventive process it is also possible to use phonic acid, hydroxyl radicals, lactam and lactone, N-Sub oriented block copolymers based on acrylate and/or meth Stituted amide, N-Substituted amine, carbamate, epoxy, thiol, acrylate. Here, mention may be made in particular, by way alkoxy, and cyano radicals, ethers or the like. of example, of those pressure Sensitive adhesives based on at least one block copolymer, the weight fractions of the 0017 Examples of moderate basic monomers are N,N- block copolymers totaling at least 50% of the pressure dialkyl-substituted amides, such as N,N-dimethylacryla mide, N,N-dimethylmethacrylamide, N-tert-butylacryla Sensitive adhesive, and at least one block copolymer being mide, N-vinyl-pyrrolidone, N-vinylactam, composed at least in part